JP2012129269A - Inductor element with core and method of manufacturing the same - Google Patents

Abstract

To increase the inductance of an inductor formed on a semiconductor substrate.
A core formed on another substrate is inserted into a coil central hole of a coil wiring formed of at least one layer formed on a semiconductor substrate. After fixing the core to the coil center hole, the separate substrate is separated. The core is patterned by attaching a thin plate of a core material (magnetic material) to another substrate via a bonding material. The coil center hole formed on the semiconductor substrate contains a fluid adhesive, and after the core is inserted, the fluid adhesive is cured and the core is fixed. After the core is fixed, the adhesive strength of the bonding agent is reduced to separate another substrate. Since the core material has the same high magnetic permeability as the bulk, an inductor having a very large inductance can be formed.
[Selection] Figure 1

Description

  The present invention relates to a high-performance inductor mounted on a semiconductor device and a manufacturing method thereof.

  An IC inductor element and an on-chip coil are configured such that a wiring pattern is spirally formed between interlayer insulating films on a Si substrate, and the inside of the coil is covered with a cavity or an insulating film. In order to form a coil having a large inductance, it is necessary to increase the number of turns of the coil or to increase the size thereof, and there is a problem that the occupied area becomes large. In order to solve this, a method has been proposed in which a coil central portion is opened and soft magnetic particles are applied and solidified with an adhesive material in the opening. However, the magnetic permeability by this method is about 10, and a great effect cannot be expected. (Patent Document 1)

Patent 4200631

  In an inductor element or on-chip coil of an IC, an inductor without a core inside the coil needs to increase the number of turns of the coil or increase the size in order to increase the inductance, and the occupied area increases. There's a problem. On the other hand, the conventional type in which the core is provided inside the coil is formed by applying and solidifying soft magnetic particles with an adhesive material as the core, and the magnetic permeability is about 10, so that a large effect cannot be expected. Is also complicated.

The present invention forms a high-performance inductor element by attaching a core having a high magnetic permeability attached to another substrate to a substrate on which a semiconductor element is formed or an inductor wiring is formed. It is.
When an inductor element is formed on a semiconductor substrate on which a semiconductor element is formed, an inductor wiring is formed on the semiconductor substrate on which the semiconductor element is formed, and a core with high magnetic permeability attached to another substrate is attached to the central portion of the inductor wiring. Let The other substrate is then removed or removed. Alternatively, an inductor with a core formed on another substrate (second substrate) is attached to a semiconductor substrate (generally referred to as a first substrate) on which a semiconductor element is formed. The second substrate is then removed or removed. Furthermore, at this time, another substrate (first substrate, second substrate) is formed at the center of the inductor wiring formed on another substrate (which may be generally referred to as a second substrate in order to distinguish from the first substrate). In order to distinguish it from the substrate, a core having a high magnetic permeability that is generally attached to the third substrate may be attached. The third substrate is then removed or removed.
In the case of forming a single inductor element, a core with high magnetic permeability attached to another substrate is attached to the central portion of the inductor wiring formed on the substrate. The other substrate is then removed or removed.

The inductor element of the present invention has a very high performance because a core with high magnetic permeability is mounted at the center thereof. That is, compared with the conventional inductor element, the inductance can be considerably increased and the Q value can be remarkably improved. The size of an inductor having an inductance having desired characteristics can be greatly reduced. Moreover, since the manufacturing method is very simple, the manufacturing cost can be greatly reduced.

FIG. 1 is a diagram showing a first embodiment of the present invention. FIG. 2 is a view for explaining a method of fixing the core 33 of the present invention in the coil central hole 17. FIG. 3 is a diagram showing the inductor by a symbol. FIG. 4 shows another embodiment to which the first embodiment of the present invention is applied. FIG. 4 shows another embodiment to which the first embodiment of the present invention is applied. FIG. 4 shows another embodiment to which the first embodiment of the present invention is applied. FIG. 4 shows another embodiment to which the first embodiment of the present invention is applied. FIG. 5 is an example of a plan view of a coil wiring pattern in the present invention. FIG. 6 is still another example in the first embodiment of the present invention. FIG. 6 is still another example in the first embodiment of the present invention. FIG. 6 is still another example in the first embodiment of the present invention. FIG. 6 is still another example in the first embodiment of the present invention. FIG. 7 is a view showing a modification of the manufacturing method shown in FIG. FIG. 7 is a view showing a modification of the manufacturing method shown in FIG. FIG. 7 is a view showing a modification of the manufacturing method shown in FIG. FIG. 7 is a view showing a modification of the manufacturing method shown in FIG. FIG. 8 is a diagram for explaining a patterning method by attaching a magnetic material to a support substrate. FIG. 9 is a diagram for explaining a method of manufacturing a support substrate in the case of having a magnetic shield material. FIG. 9 is a diagram for explaining a method of manufacturing a support substrate in the case of having a magnetic shield material. FIG. 10 is a diagram for explaining another method for producing a support substrate having a magnetic shield material. FIG. 10 is a diagram for explaining another method for producing a support substrate having a magnetic shield material. FIG. 11 is a diagram showing the structure of a semiconductor device equipped with the inductor of the present invention. FIG. 12 is a diagram showing an example of another support substrate to which the magnetic body of the present invention is attached. FIG. 13 is a diagram showing a fourth embodiment of the present invention. FIG. 14 occupies a modification of the third embodiment. FIG. 15 is a diagram showing a basic structure of the lateral inductor of the present invention. FIG. 16 is a diagram illustrating a method for manufacturing a horizontal inductor. FIG. 17 is a diagram for explaining another method for manufacturing a horizontal inductor. FIG. 18 is a diagram for explaining an embodiment of a method for manufacturing a horizontal inductor according to the present invention. FIG. 19 is a diagram for explaining a process in which the photosensitive film is used on the first conductor film to be the lower coil wiring. FIG. 20 is a diagram illustrating a process of an embodiment of the horizontal inductor according to the present invention. FIG. 21 is a diagram showing one process in the lateral inductor of the present invention. FIG. 22 shows a variation of the method for manufacturing the horizontal inductor shown in FIG. FIG. 23 is a diagram showing a manufacturing method of one embodiment of the vertical inductor of the present invention. FIG. 23 is a diagram showing a manufacturing method of one embodiment of the vertical inductor of the present invention. FIG. 24 is a diagram showing a variation of FIG. FIG. 25 is a diagram showing a toroidal coil manufactured using the lateral inductor of the present invention. FIG. 26 is a view showing the structure of a package manufactured using the vertical inductor of the present invention. FIG. 27 is a view for explaining a method of mounting a large number of inductor element packages of the present invention formed on a substrate on another substrate.

The outline of the first embodiment of the present invention will be described with reference to FIG. The outline will be described. A core formed on a separate substrate is inserted into a coil central hole of a coil wiring formed of at least one layer formed on a semiconductor substrate. After fixing the core to the coil center hole, the separate substrate is separated. The core is patterned by attaching a thin plate of a core material (magnetic material) to another substrate via a bonding material. The coil center hole formed on the semiconductor substrate contains a fluid adhesive, and after the core is inserted, the fluid adhesive is cured and the core is fixed. After the core is fixed, the adhesive strength of the bonding agent is reduced to separate another substrate. Since the core material has the same high magnetic permeability as the bulk, an inductor having a very large inductance can be formed. More specifically, the inductor according to the present invention is formed on the second substrate by forming at least one layer of coil wiring on the first substrate which is a semiconductor substrate, an insulating substrate, or a conductive substrate. Manufactured by a method of manufacturing an inductor with a core including a step of disposing a core inside the coil wiring and a step of separating the core from the second substrate. In this case, after the step of forming the coil wiring, the step of applying a fluid adhesive, the step of forming an adhesive layer on the inner bottom of the coil wiring, or the core formed on the second substrate It is manufactured by a manufacturing method further including any one of the steps of forming the adhesive layer or a combination of these steps. Alternatively, in the inductor of the present invention, a step of forming at least one layer of coil wiring on a first substrate which is a semiconductor substrate, an insulating substrate, or a conductive substrate, and a step of forming a central hole inside the coil wiring And a method of manufacturing a cored inductor including a step of inserting a core formed on a second substrate into the central hole and a step of separating the core from the second substrate. Furthermore, in this case, after the step of forming the central hole inside the coil wiring, a step of applying a fluid adhesive, a step of forming an adhesive layer at the bottom of the central hole, or on the second substrate It is manufactured by a manufacturing method further including any step of forming an adhesive layer on the formed core, or a step combining these steps.

As shown in FIG. 1A, a conductor wiring 13 serving as a coil wiring is formed on an insulating film (SiO film, SiN film, SiON film, etc.) 12 on a silicon substrate 11. In FIG. 1A, two-layer conductor wirings 13 and 15 are shown, but a single-layer wiring or three-layer or more wiring may be used. As conductor films, metals such as aluminum (Al), titanium (Ti), tungsten (W), copper (Cu), gold (Au), iron (Fe), cobalt (Co), nickel (Ni), and these An alloy, polycrystalline silicon (PolySi), amorphous silicon, tungsten silicide (WSi), silicide such as molybdenum silicide, titanium silicide, conductive plastic, or a composite material thereof can be used. The first layer and the second layer wiring may be connected, and in this case, they are connected spirally or spirally. That is, the starting point of the first layer wiring 13 is connected to a desired electrode, but the end point of the first layer wiring 13 is connected to the starting point of the second layer wiring 15. The first-layer wiring 13 and the second-layer wiring 15 are separated from each other by the interlayer insulating film 14, but the end point of the first-layer wiring 13 is formed at the starting point of the second-layer wiring 15 in the interlayer insulating film. Electrical connection is made by a conductor film formed in the contact hole. The end of the second layer wiring 15 is connected to a desired electrode. It should be noted that the connection can be repeated in this manner even when the third or more layers are formed. When a voltage is applied between these electrodes, a current flows from the first layer to the second and subsequent layers (or vice versa). Further, it is possible to control the coil by flowing current for each wiring without connecting each wiring. Further, the wirings may be wound spirally in the horizontal, ie, planar, double or triple, without vertically stacking the wirings in a spiral shape. The inductance of the inductor (coil) increases in proportion to n ² when the number of turns is n.

Thus, the coil central hole 17 is formed by removing the central portion 17 of the wiring formed in a spira-like, circular or rectangular shape. After forming the second layer wiring 15 (the uppermost layer in the case of a multilayer wiring), an insulating film 16 is usually formed thereon, and the central portion of the coil is opened using a photolithographic method. The insulating film under the opening is etched by dry etching. The insulating film under the opening is usually a laminated film of the insulating film 12 on the silicon substrate 11, the insulating film 14 thereon, and the insulating film 16 thereon. Since it is possible to remove the insulating film present in the coil center hole 17 when forming the hole, there may be no part of it. The coil central hole 17 may be opened to the inner side of the coil wirings 13 and 15. In this case, the distance between the core and the wire entering the coil center hole 17 can be made considerably closer, and the size can be reduced when obtaining a desired inductance. Further, the inner portions of the coil wirings 13 and 15 can also be removed by etching. In this case, after the coil center hole 17 is formed so that the coil wirings 13 and 15 are exposed to the coil center hole 17 and do not come into contact with the core entering the coil center hole 17, the insulating film 18 is formed. If there is no such problem, the insulating film 18 may not be formed.

In some cases, the insulating film is not etched to form the coil center hole 17. For example, when a first layer of coil wiring is formed by etching into a vertical shape and then a conformable insulating film is laminated by a CVD method, a central hole is formed inside the coil wiring. If the coil wiring is thick, a deep central hole corresponding to it is formed. When two or more layers of coil wiring are formed, an insulating film is formed between the upper and lower coil wirings, and if a connection hole for connecting the upper and lower coil wirings is also etched, There is no need to add a process of making only the central hole. In addition, when using a photosensitive resin as an insulating film, or when using another insulating film and a photosensitive resin together, the center inside the coil wiring is used when the connection hole between the coil wirings is formed by photolithography. Similarly, the portion corresponding to the hole may be opened by the photolithography method.

Next, the fluid adhesive 19 is applied. Since the coil center hole 17 is recessed, the fluid adhesive 19 is applied thicker than other portions. Next, the core 33 formed on the support substrate 31 is inserted into the coil center hole 17. The core 33 is formed smaller than the size of the coil center hole 17 (with respect to the lateral direction) so that the core 33 can be inserted into the coil center hole 17. With respect to the vertical direction, the core 33 is formed in a columnar shape, and the core 33 may be completely inserted into the coil center hole 17, or the height may be increased so that the head protrudes from the coil center hole 17. good. The core 33 is attached to the support substrate 31 with a bonding agent. In order to allow the core 33 to completely enter the coil center hole 17, it is necessary to adjust the thickness of the bonding agent that adheres the core 33 to the support substrate 31 in order to enter the coil center hole 17. Further, when the bottom of the coil center hole 17 is made lower than the coil wiring of the first layer and the bottom of the inserted magnetic body 33 is made lower than the coil wiring of the first layer, the coil wiring 13 is wound around the core 33 Thus, the inductance and the Q value are also improved.

In order to accurately insert the core 33 on the support substrate 31 into the coil center hole 17 on the silicon substrate 11, it is necessary to accurately align the support substrate 31 with the silicon substrate 11. Alignment marks can be formed on the silicon substrate 11 and the support substrate 31, respectively, or can be directly aligned with the already formed pattern. In addition, after or after fitting, the device on which the support substrate 31 is mounted is brought close to the device (or the base) on which the silicon substrate 11 is mounted, while maintaining the parallelism. The core 33 on the support substrate 31 can be accurately inserted into the coil center hole 17 on the silicon substrate 11. Even at present, this alignment error is about 0.5 μm at 6σ, but it is said that it can be adjusted in the nm (nanometer) order in the future. Therefore, it is necessary to determine the size of the core 33 on the support substrate 31 and the hole size of the coil central hole 17 on the silicon substrate 11 in accordance with the fitting accuracy of the time. When the core 33 on the support substrate 31 is inserted into the coil central hole 17 on the silicon substrate 11, the fluid adhesive 19 is contained in the coil central hole 17, so that the core 33 is contained in the fluid adhesive 19. Infiltrate. The fluid adhesive 19 in the coil center hole 17 is pushed outward by the amount of the core 33.

As shown in FIG. 1B, the approach of the support substrate 31 is stopped when the core 33 enters a predetermined position in the coil center hole 17. Thereafter, the core 33 is removed from the support substrate 31. As a method of removing the core 33 from the support substrate 31, the bonding force of the bonding agent 32 may be reduced or eliminated by heating. For example, when selecting a material in which the curing temperature of the fluid adhesive 19 is 80 ° C. or higher and the softening temperature of the bonding agent 32 is 90 ° C. or higher, first, heat treatment is performed at about 80 ° C. to 90 ° C. Then, the fluid adhesive 19 is cured to fix the core. Next, if heat treatment is performed at 90 ° C. or higher, the bonding force of the bonding agent 32 decreases, and the core 33 can be separated from the support substrate 31. As such a material, for example, there are many epoxy adhesives as the fluid adhesive 19. (Technodyne AH manufactured by Taoka Chemical Industries is cured at 80 to 100 ° C.) As the bonding agent 32, there is an acrylic adhesive. (GL-3005 series of Glue Lab Co., Ltd. is easily peeled off by hot water or heating at 90 to 100 ° C.)

Alternatively, a metal material may be used as the bonding agent 32. For example, a solder alloy having a melting point of 150 ° C. to 300 ° C. is used. Using the fluid adhesive 19 that cures below the melting point, the fluid adhesive 19 is cured by heat treatment below the melting point, the core 33 is fixed, and then the bonding agent 32 is melted by heat treatment below the melting point. The core 33 is removed from the support substrate 31.
Alternatively, an adhesive that peels off by ultraviolet irradiation may be used as the bonding agent. After the fluid adhesive 19 is cured under predetermined conditions to fix the core 33, ultraviolet rays are irradiated to reduce the adhesiveness of the bonding agent 32, and the core 33 is removed from the support substrate 31.

As the fluid adhesive 19, an inorganic coating film of inorganic type SOG (Spin On Glass) such as silanol type or hydrogenated silsesquioxane (HSQ) type can also be used. An organic polymer coating film such as polyimide or an organic SOG film such as methylsilsesquioxane (MSQ) can also be used. When a fluid adhesive is used, it may be used in combination with an insulating film laminated by a CVD method or a PVD method in order to improve reliability. For example, there is a method of applying a fluid adhesive after laminating an insulating film by a CVD method or a PVD method.
As described above, by appropriately selecting the bonding agent 32 and the fluid adhesive 19, the core 33 can be fixed in the coil center hole 17 and separated from the support substrate 31.

Alternatively, the support substrate 31 is used as an electromagnet, and the core 33 is directly attached to the support substrate without using the bonding agent 32. Since the core 33 is a magnetic material, it adheres to the support substrate. If the electromagnet of the support board 32 is released after the insertion of the core 33 is completed, the core 33 is easily separated from the support board 31. If this method is used, it is not necessary to consider the characteristics of the bonding agent 32, so various fluid adhesives 19 can be used.
In addition, although the term fluid adhesive was used, the adhesive here is adhesive in the sense that the core 33 is fixed and adheres to the insulating film on the silicon substrate 11, and what is a normal adhesive? It also has a different meaning.

FIG. 1C shows a state where the core 33 is separated from the support substrate 31. The core 33 is fixed in the coil center hole 17. The surface of the cured fluid adhesive 19 and the upper surface of the core 33 are not necessarily at the same level, and the surface is not flat. Since the core 33 is exposed, an insulating film as a protective film may be laminated thereafter to cover the core 33. The insulating film is a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like, and can be stacked by a CVD method or a PVD method. Alternatively, a coating film such as SOG or polyimide may be coated and heat-treated to be solidified. In order to improve the moisture resistance, it is preferable to stack a silicon nitride film or a silicon oxynitride film. Alternatively, these insulating films may be used in combination.
When it is desired to flatten the surface, after the state shown in FIG. 1 (c), an organic coating film such as SOG or polyimide is applied to be flattened, or the surface is polished by CMP (Chemical-Mechanical Polishing) or the like. And may be flattened.

In order to stabilize the potential of the core 33, the lower surface and / or the upper surface of the core 33 may be connected to another electrode. Alternatively, the core 33 may be connected to the lower surface electrode and the upper surface electrode so as to surround the coil wiring. Or you may make so that coil wiring may be surrounded, without electrically connecting.

FIG. 2 is a view for explaining a method of fixing the core 33 in the coil center hole 17 by a method different from that in FIG. In the method shown in FIG. 2, the fluid adhesive 19 is not used. Instead, the adhesive layer 34 is attached to the bottom surface of the core 33 attached to the support substrate 31. There are various methods for attaching the adhesive layer 34 to the core 33. For example, after the core 33 is patterned on the support substrate 31, the support substrate 31 may be carried to a place where the adhesive liquid exists and the bottom surface of the core 33 may be immersed. The adhesive liquid may be attached to the entire periphery of the columnar core 33, or may be attached only to the bottom surface of the core 33 as shown in FIG. Since this step can be performed in a series of steps of moving the support substrate, the process load is small.

Next, as shown in FIG. 2B, the support substrate 31 is brought close to the silicon substrate 11, and the core 33 is attached to the bottom surface in the coil center hole 17 via the adhesive layer 34. The adhesive layer 34 may be a low melting point metal or a low melting point alloy. The silicon substrate 11 is heated to a temperature equal to or higher than the melting point to melt the low melting point metal or the like, and then the temperature of the silicon substrate 11 is lowered to the melting point or lower to attach and fix the core 33 to the silicon substrate 11 side. Thereafter, the core 33 is separated from the support substrate 31. In this case, a material having a temperature at which the adhesive strength of the bonding agent 32 becomes weaker than a melting point such as a low melting point metal may be used. A material that weakens the adhesive force by ultraviolet irradiation or the like may be used for the bonding agent 32. Alternatively, the core 33 may be separated from the support substrate 31 and the core 33 may be placed in the coil center hole 17 and then the silicon substrate 11 may be heated to adhere the core 33 to the silicon substrate. For example, a material whose adhesive strength is reduced at a temperature lower than the temperature at which the adhesive layer 34 is adhesively cured may be used for the bonding material 32. After placing the core 33 on the bottom surface in the coil center hole 17, the support substrate is heated to a temperature at which the adhesive strength of the bonding material is lowered to separate the core 33 from the support substrate 31. Thereafter, the silicon substrate is heated at a temperature higher than the temperature at which the adhesive layer adheres and cures, and the core 33 is attached to the bottom surface of the coil center hole 17.

FIG. 2C shows a state where the core 33 is attached in the coil center hole 17. In this state, a slight gap is generated between the side wall portion of the columnar core 33 and the side wall portion of the coil central hole 17. This gap is inevitably generated because it is necessary to consider the alignment error between the support substrate and the silicon substrate. If a problem occurs due to accumulation of moisture when used in this state, the insulating film 20 is laminated to cover the core 33 and the gap as shown in FIG. The insulating film 20 is a silicon oxide film, a silicon nitride film, a silicon oxynitride film, or the like, and can be laminated by a CVD method or a PVD method. Alternatively, a coating film such as SOG or polyimide may be coated and heat-treated to be solidified. Alternatively, these insulating films can be used in combination.

FIG. 3 shows the inductor by a symbol. An inductor is also called a coil, but a coil is defined in JIS C5602 “Passive component terms for electronic equipment” as “coil: a component having a self-inductance that is generally made by winding a conductor on the surface of an insulator”. ing. On the other hand, an inductor means an “inductive element”, but “a coil with one winding” may be called an inductor, and the difference between the inductor and the coil is not clear. In the present specification and claims, the coil and the inductor are not distinguished from each other and are considered as “a component (element) having a self-inductance formed by winding a conductor on the surface of an insulator”. That is, the case of one winding is also called a coil or an inductor, and the case of two or more windings is also called a coil or an inductor.

An AC or DC voltage is applied to terminals A and B at both ends of the inductor 40 shown in FIG. A core (core) 41 is placed in the center of the inductor, and a conductor 42 surrounds the core 41. A conductor 42 surrounding the core 41 is called a coil wiring 42. The coil wiring 42 may be used including the terminals A to B at both ends. The self-inductance L of the inductor 40 is approximately expressed as L = k * u * n ² S / l, and is proportional to the square of the number of turns n, the cross-sectional area S inside the winding, and the magnetic permeability u of the core. Is inversely proportional to the length l. Therefore, the value of L varies depending on the core material. k is a Nagaoka coefficient. u = (vacuum permeability) * relative permeability, relative permeability is 1.0 for air core (air), about 18000 for iron core, 1000-20000 for Mn-Zn ferrite, about 20000 for permalloy That's it. The Q value indicating the quality of the inductor is indicated by Q = ωL / r, and is proportional to each frequency ω and L and inversely proportional to the effective resistance value r. From this, it can be seen that increasing L improves the quality of the inductor. Therefore, if a material having a high magnetic permeability μ can be used for the core, an inductor having a high performance and a small size can be manufactured.

FIG. 4 shows another embodiment to which the first embodiment of the present invention is applied. As shown in FIG. 4A, electrodes / wirings 53 are formed on an insulating film 52 on a silicon substrate 51. Although active elements such as transistors and passive elements such as resistors are formed on the silicon substrate 51, only the portion directly related to the inductor is shown in FIG. That is, the electrodes / wirings 53 (53-1) and 53 (53-2) are both terminals of the inductor (assuming that A, B, A correspond to 53-1, and B corresponds to 53-2 shown in FIG. 3). It is an electrode / wiring connected to. 53 (53-3) is an electrode / wiring that is not connected to the inductor but blocks the electromagnetic field of the inductor from leaking outside. 53 (53-3) may be in a floating state, but may be connected to the silicon substrate 51, another electrode wiring, or a semiconductor element in order to stabilize or control the potential. Since the inductor of the present invention can be incorporated after the semiconductor device is completed, the electrodes and wiring are formed of aluminum (Al), copper (Cu), gold (Au), other metals, or alloys thereof. Alternatively, the inductor of the present invention can be incorporated even before the semiconductor device is completed. In that case, in addition to the above materials, polycrystalline silicon (Poly-Si), tungsten silicide (WSi), titanium silicide ( Metal silicide such as TiSi) and molybdenum silicide (MoSi), refractory metal such as chromium (Cr), tungsten (W), titanium (Ti) and molybdenum (Mo), conductive carbon, or highly conductive polymer, It may be a composite. The electrodes / wirings 53 (53-1 to 53-3) are covered with the insulating film 54, and the portions 55 (55-1, 55-2) connected to the inductor terminals are opened. The insulating film 54 is a silicon oxide film, a silicon nitride film, a silicon oxynitride film, an insulating film such as SOG or a polyimide film laminated by CVD or PVD, and an insulating film cured by heat treatment or a composite film thereof. It is. When the opening 55 is formed, the opening 55 can be formed by a photolithography method and an etching method. Alternatively, if a photosensitive insulating film such as photosensitive polymimide is used, a photosensitive polyimide film can be applied and the prebaked opening can be formed by an exposure method without using a photoresist film or an etching method. The insulating film 54 having the above can be formed.

Reference numeral 53-3 denotes an electrode / wiring that blocks the electromagnetic field, but it may be formed of the same material as the other electrodes / wirings 53-1, 53-2, or may be separated to improve the shielding property. You may form with the material (for example, magnetic body).

Next, a material for a first layer coil wiring is laminated, and a desired coil wiring is formed by a photolithography method. This state is shown in FIG. From the state of FIG. 4A, a material to be the first layer coil wiring 56 is laminated. This material is Al, Cu, silicide, refractory metal, conductive carbon, highly conductive polymer, or a composite thereof. In order to increase the Q value, it is preferable that the resistance is low. Therefore, Al, Cu, gold (Au), or an alloy or composite thereof is preferable. This material 56 is formed by a CVD method, a PVD method, a plating method, or a coating method. The coil wiring 56 is connected to the electrode / wiring 53 through the openings 55-1 and 55-2. In order to improve this connectivity, impurities or residual insulating film present on the electrode / wiring 53 (53-1, 53-2) may be removed in the opening 55 (55-1, 55-2). For example, pre-processing such as wet etching or dry etching can be performed before the first-layer coil wiring 56 is stacked. Alternatively, reverse sputtering (sputter etching) can also be performed using the same sputtering apparatus before lamination by the sputtering method. Furthermore, a barrier metal may be interposed between the electrodes / wirings 53 (53-1, 53-2) and 56 in order to improve connectivity and adhesion. Examples of the via metal include titanium tungsten (TiW), titanium nitride (TiN), titanium tungsten (TiW), titanium (Ti), and a composite thereof. Of course, other materials that can improve connectivity and adhesion may be used.

Next, in order to form and form a coil wiring 56 having a desired pattern, a photoresist is applied, a portion other than the coil wiring is removed by a light exposure method, and the patterned photoresist is baked and hardened. Thereafter, the exposed coil wiring material 56 is etched to obtain a desired coil wiring 56. The resist on the coil wiring is removed by a wet method or a dry method (ashing method), and a pattern shown in FIG. 4B is obtained. 4 shows a cross section of the silicon substrate. In FIG. 4B, the coil wirings 56-1 and 56-3 are shown separately, but the coil wiring 56 is actually spiral. The coil wirings 56-1 and 56-3 are connected continuously. However, one electrode / wiring 53-2 is not connected to the spiral wiring (56-1 and 56-3) of the first layer when the coil wiring has a multilayer structure. The purpose of forming the first coil wiring layer 56-2 on the electrode / wiring 53-2 at this stage is to prevent the formation of deep connection holes. When forming a deep connection hole, the etching time may become longer when the connection hole is formed, and the etching apparatus may be overloaded, or it may be difficult to cover and connect the conductive film in the deep connection hole. There is. Therefore, the electrode / wiring 53-2 is opened (opening 55-2), and the coil wiring 56-2 is patterned and left in this portion when the first layer coil wiring 56 is formed.

FIG. 5 is an example of a plan view of a coil wiring pattern. FIG. 5A is an example of a plan view corresponding to the state of FIG. 73 shown by a broken line is an electrode / wiring pattern and corresponds to 53 in FIG. The pattern indicated by 73-1 corresponds to the electrode / wiring 53-1, and the pattern indicated by 73-2 corresponds to the electrode / wiring 53-2. 73-3 corresponds to the electrode / wiring 53-3. 75 is an opening formed in the insulating film 54 in FIG. 4, 75-1 is an opening on the electrode / wiring 73-1, and 75-2 is an opening on the electrode / wiring 73-2. is there. Reference numeral 76 denotes a first layer coil wiring, in which the coil wiring is wound in a square shape. The quadrangular shape may be a circular shape, a polygonal shape, or an elliptical shape. The coil wiring 76 of the first layer is in contact with the electrode / wiring 73-1 in the opening 75-1, and this portion is referred to as a terminal part 76-1 of the coil wiring. The coil wiring 76 of the first layer starts from the terminal portion 76-1 and is wound for one round in a square shape, and is wound up to the contact portion between the first layer coil wiring 76 and the second layer coil wiring 79. ing. This portion is referred to as a first layer coil wiring contact portion 76-4. In this portion, a contact hole 78 with the coil wiring 79 of the second layer is formed.

In FIG. 3, one terminal A of the inductor corresponds to 76-1, but 73-2, which is an electrode / wiring connected to the other terminal B, has a connection wiring with high reliability as described above. The opening 75-2 is opened, and the first layer coil wiring is formed to cover the opening 75-2. This coil wiring is referred to as 76-2. As can be seen from FIG. 5A, 76-2 is not connected to the annular first coil wiring 76. 56-3 in FIG.4 (b) respond | corresponds to 76-3 in Fig.5 (a). When there is only one layer of coil wiring, the coil wiring is completed with one turn shown in FIG. Therefore, 76-2 and 76-4 match. Since the self-inductance L increases when the coil wiring is made as much as possible, it is preferable to bring the other electrode / wiring 73-2 near one electrode / wiring 73-1. In FIG. 5 (a), 73-2 should be brought to the position 76-4. In the present invention, since a core having a magnetic permeability of 10,000 or more can be used, a predetermined inductance can be obtained even with one turn (that is, even with one layer). In the case of one winding, since the contact hole 78 with the coil wiring of the second layer is unnecessary, a very simple process is sufficient.

Since the electrode / wiring 73-3 is intended to shield the electromagnetic field, it is patterned so as to surround the entire coil wiring 76 as much as possible. That is, it is preferable to cover a wide area so as not to contact the electrodes / wirings 73-1 and 73-2. However, if the characteristics of the insulating film on it deteriorates if it is too wide (for example, when a crack occurs in the insulating film), it is effective to make a slit in the electrode / wiring 73-3. Needless to say, this is not necessary if it is not necessary to provide 73-3.

Returning to FIG. 4, next, as shown in FIG. 4C, an insulating film (referred to as a second insulating film) 57 is laminated on the first-layer coil wiring 56. The second insulating film is laminated so that the first-layer coil wiring 56 and the second-layer coil wiring 61 do not come into contact with each other except for the connection holes. As the second insulating film, a silicon oxide film, a silicon nitride film, a silicon oxynitride screen, an SOG coating film, a polyimide film, or a composite film thereof can be used. When flattening is required, a coating film such as an SOG film or a polyimide film, a planarization insulating film by bias sputtering or bias CVD, an etching back method, or a polishing method by CMP can be used.

Next, as shown in FIG. 4C, a photoresist 58 is applied, and a portion of the photoresist 58 where a contact hole is to be formed between the first layer coil wiring 56 and the second layer coil wiring is formed by an exposure method. Open. 59 is this opening. Using this photoresist 58 as a mask, the underlying insulating film 57 is etched from the opening 59 to open a contact hole 60 (shown in FIG. 4D). This etching may be wet etching or dry etching. When it is not desired to increase the size of the contact hole 60, dry etching, particularly anisotropic dry etching is performed. After the contact hole 60 is formed, the photoresist is removed by wet or dry (ashing). If the insulating film 57 is formed of a photosensitive insulating film such as a photosensitive polyimide film, the contact hole 60 can be formed directly by the exposure method without using the photoresist 58. The photosensitive polyimide film is coated on the silicon substrate 51 by a method similar to that for the photoresist film, that is, a coating method, pre-baked, and then exposed using a mask or a reticle. After exposure, the contact hole 60 is opened by dipping in a developing solution or the like. Thereafter, heat treatment is performed to obtain characteristics required for the polyimide film as an insulating film. If a photosensitive insulating film is used, an insulating film forming process by a CVD or PVD method and a contact hole etching process can be omitted.

When only one coil wiring is required, the contact hole can be used as a pad opening. In this case, the inductor terminal itself can be used as a pad opening, and a voltage (AC voltage or DC voltage) can be applied from the outside of the semiconductor element. Alternatively, the coil wiring of the inductor element can be connected to the electrode / wiring 53 and a pad electrode can be provided in the area of the other electrode / wiring.

Next, as shown in FIG. 4E, a second layer coil wiring material 61 is laminated. A coil wiring material 61 is also laminated inside the contact hole 60. The coil wiring material 61 is preferably the same material as the first-layer coil wiring material because it does not increase the contact resistance. However, if the contact resistance does not increase much, a different conductor material may be used. It is only necessary to interpose a conductor material that lowers the contact resistance between different materials. In the case where the adhesion to the insulating film 57 is not good, a conductor material that improves the adhesion may be stacked. For example, when the coil wiring material is chromium (Cr) or Cu, these conductor films may be laminated after thinly laminating Ti. When the coverage (step coverage) of the coil wiring material 61 to the contact hole 60 is poor and problems such as disconnection may occur, the contact hole 60 can be forward tapered to improve the coverage. Alternatively, the conductor film may be laminated by bias sputtering or bias CVD. Alternatively, the coil wiring material 61 may be grown by a plating method. In the case of the plating method, there is a method of performing plating after forming a seed layer. For example, when the coil wiring material 61 is Cu, Cu does not have good adhesion to the insulating film, and may not grow sufficiently by electroless plating. Adhesion with the film 57 is ensured, and then Cu is laminated by the PVD method. After laminating the desired thickness, Cu plating is performed. The electrolytic plating of Cu is performed by immersing the silicon substrate 51 in a plating solution such as a copper sulfate solution.

After the second-layer coil wiring 61 is laminated, a photoresist 62 is applied and the photoresist 62 other than the portion to be left as the coil wiring is removed by an exposure method to obtain a desired photoresist pattern 62. Using this photoresist as a mask, the second-layer coil wiring 61 is etched to remove unnecessary coil wiring material. After the etching is completed, the photoresist 62 is removed by a wet or dry method. This state is shown in FIG. As shown in FIG. 4 (f), the second layer coil wiring is the first layer via the contact hole 60-1 at the terminal portion (76-4 in FIG. 5 (a)) of the first layer coil wiring 56. It is connected to the coil wiring 56 of the eye. This connecting portion is 61-1. It is wound in an annular shape through the connecting portions 61-1 to 61-3. Further, the electrode / wiring 53-2 (here, the first layer coil wiring material 56-2 is already formed through the opening 55-2) and the contact hole 60 connected to the other terminal of the inductor. -2 is formed through the second line 61-2. When the coil wiring ends in two layers, the 61-2 and the substantial coil wiring 61 (wiring wound from 61-1 to 61-3) are continuously connected. This process is repeated in the case of three or more layers of coil wiring.

FIG. 5B is a plan view of the state in FIG. The first layer coil wiring 76 is indicated by a broken line. The second-layer coil wiring 81 (corresponding to 61 in FIG. 4) is connected to the terminal portion 76-4 of the first-layer coil wiring 76 wound in an annular shape through a contact hole 78-1 (corresponding to 60-1 in FIG. Connect). This portion is 81-1 and corresponds to 61-1 in FIG. The second layer coil wiring 81 is also annularly wound into a rectangular shape through the second layer coil wiring 81-3 (corresponding to 61-3 in FIG. 4). The rectangular shape may be a triangular shape, a quadrangular shape, a polygonal shape, a circular shape, an elliptical shape, or the like, similarly to the first layer coil wiring. The coil wiring 81 is further wound after one round, and is connected to the other electrode / wiring 73-2 via the first layer coil wiring material 76-2 and the contact hole 78-2. When there are three or more layers of coil wiring, the above is repeated. 4 and 5, the first layer coil wiring is wound for one turn, and the second layer coil wiring is wound for one turn (exactly, in FIG. 5, a little extra), Since the inductance L is proportional to the square of the number of turns, the number of turns may be increased. As a method of increasing the number of windings, there are a method of winding in a plane as shown in FIG. 5 and a method of stacking in the vertical direction.

Returning to FIG. Next, as shown in FIG. 4G, an insulating film 63 is laminated on the second layer coil wiring 61. This insulating film is a silicon oxide film, a silicon nitride film, a silicon oxynitride film, a coating film such as SOG or a polyimide film, or a composite film thereof.
Next, as shown in FIG. 4 (h), in order to remove the insulating film on the inner part of the coil wiring (that is, to form a coil wiring central hole), a photoresist 64 is applied and the coil wiring is formed by an exposure method. The inner part 65 of the window is opened. The size of the window opening portion 65 is such that when the insulating film is removed and the core (core 9) is inserted and embedded, the core does not contact the coil wiring, and there is no problem in electrical characteristics and reliability. In addition to the size of the level, the size of the core should be as close as possible to the coil wiring in order to improve the inductor performance.

Below the window opening portion 65 of the photoresist 64, there are an insulating film 63, an insulating film 57, an insulating film 54, and an electrode / wiring 53-3 therebelow. However, although not described so far, the insulating film 54 and the insulating film 57 can be removed at the same time when the opening 55 and the connection hole 60 are formed. There is only an insulating film 63 on the top. The insulating film present in the windowed portion 65 is removed to form a coil wiring center hole 66 as shown in FIG. The insulating film is removed by wet etching or dry etching. For example, when the insulating film is a silicon oxide film (SiO), a hydrofluoric acid-based etchant is used for wet etching, or a CF-based gas such as CF ₄ gas, a CHF-based gas, an SF-based gas, or the like is used for dry etching. Can be used. The electrode / wiring 53-3 serves as an etching stopper for the insulating film. However, the electrode / wiring 53-3 may be etched to leave a little insulating film on the electrode / wiring 53-3.

Next, after removing the photoresist 64, a fluid adhesive 67 is applied. As shown in FIG. 4 (j), the fluid adhesive 67 accumulates thickly in the coil center hole 66. As the fluid adhesive 67, in addition to the materials described above, an insulating coating film such as polyimide, photoresist, or SOG may be used. In a state where the fluid adhesive is accumulated in the coil center hole 66 and has fluidity, a support substrate 68 to which the core 71 is attached is prepared, and the support substrate 68 is brought close to the silicon substrate 51 while patterning. I will let you. The core 71 is a magnetic material having a high magnetic permeability, and is previously patterned so that it can be inserted into the coil center hole 66. A large number of semiconductor devices are formed on the silicon substrate 51, and a large number of coil center holes exist. Since cores are inserted into the large number of coil center holes, it is necessary that the support substrate 68 has a large number of cores formed at accurate positions. In the support substrate shown in FIG. 4J, a magnetic shield material 70 is coupled to the upper end of the columnar core 71. The magnetic shield material 70 is a magnetic material or a conductor material, but a magnetic material having a high magnetic permeability is preferable for improving the electromagnetic shielding effect. Therefore, the same material as the core 71 may be used. The core 71 and the magnetic seal material 70 may be adhered by adhesion or may be an integral object. In the case of the same material, it can be easily created as an integral object. For example, a thin magnetic plate having a high magnetic permeability, which serves as a core and a magnetic shield material, is attached to the support substrate 68 via a bonding agent 69. Photoresist is coated on the magnetic thin plate, and the photoresist is left in the portion to be the core by an exposure method. Using this photoresist as a mask, the thin plate is etched by a wet method or a dry method. Stop etching when the core has reached the desired thickness. Next, after removing the photoresist, the photoresist is applied again, and the photoresist is patterned to a size larger than the core and to the size of the magnetic shield. The magnetic material is completely etched using this photoresist as a mask. After the etching is completed, the photoresist can be removed to obtain the support substrate 68 having the pattern of the core 71 and the magnetic shield 70 shown in FIG. The size of the core 71 is large enough to enter the coil center hole 66. However, if the size of the magnetic shield covers the coil wiring as wide as possible, the effect of the electromagnetic shield is enhanced.

Next, as shown in FIG. 4K, the support substrate 68 is lowered and the core 71 is inserted into the coil center hole 66. Since the fluid adhesive 67 exists in the coil center hole 66, the core 71 is immersed in the fluid adhesive 67. The fluid adhesive 67 is pushed out of the coil center hole 66 by the amount of immersion of the core 71. When the depth reaches a predetermined depth, the approach between the support substrate 68 and the silicon substrate 51 is stopped. FIG. 4 (l) shows the dimensions in the stopped state. A state where the bottom surface of the magnetic shield 70 is in contact with the fluid adhesive 67 and is slightly immersed is preferably set as the stop position. If it stops before contacting, a gap may be formed between the magnetic shield 70 and the fluid adhesive 67, causing a problem in reliability. Further, if the bottom surface of the magnetic shield 70 is too close to the silicon substrate 51, the silicon substrate 51 may be damaged or cracked. Further, the side surface of the core 71 is prevented from contacting the side wall of the coil center hole 66 and the bottom surface of the core is prevented from contacting the semiconductor substrate 51 (that is, the electrode / wiring 53-3).

The thickness of the core 71 is a, the distance between the bottom surface of the core 71 and the electrode / wiring 53-3 is b, the lateral width of the core 71 is c, the distance between the core 71 and one side surface of the coil central hole 66 is d, the core 71 And the distance between the bottom surface of the magnetic shield 70 and the insulating film 63 (that is, the thickness of the fluid adhesive 67 at that portion) f, and the bottom surface of the magnetic shield 70. Let g be the thickness of the fluid adhesive 67 that is not in contact, and h be the thickness of the magnetic shield 70. The conditions are determined so that f + i = a + b. For example, if a = 20 μm and b = 0.3 μm, i = 20 μm and f = 0.3 μm. The lateral width of the central hole 66 = c + d + e. However, when d = e = 1 μm and the lateral width of the central hole 66 is 102 μm, c = 100 μm. Since the effect of the magnetic shield is obtained if it is about 1 μm, h is set to 1 μm or more. Note that g> f. Further, when the magnetic shield is not used, it is preferable that the core 71 is not completely immersed in the fluid adhesive 67 because the core 71 is directly attached to the bonding material. Therefore, a + b> i + f, and in this case, f = g. This is because the fluid adhesive 67 is solidified by heat treatment thereafter, so that the bonding agent 69 and the support substrate 68 are preferably prevented from adhering to the fluid adhesive 67. However, this is not the case when the magnetic shield 70 and the core 71 can be removed from the bonding agent 69 before the fluid adhesive 67 is solidified. If a = 2 μm and b = 0.3 μm, for example, i = 2 μm and f = 0.3 μm.

When there is no magnetic shield, the core 71 may be completely buried in the fluid adhesive 67. However, in this case, the bonding agent 69 is thickened and the bonding agent 69 not bonded to the core 71 is removed. It is good to keep. For example, when i = 3 μm and a = 2.5 μm, the thickness of the bonding agent is set to 0.5 μm or more. In this way, the support substrate 68 does not come into contact with the pattern on the semiconductor substrate 51. Further, the core 71 may be extended to the outside of the fluid adhesive 67. For example, when i = 1.5 μm, b = 0.3 μm, a is 3.0 μm, and f = 0.5 μm, the core comes out 1.3 μm. If there is no particular problem even if the core 71 protrudes, it may be left as it is. However, if there is a problem in reliability such as moisture resistance, the core 71 may be covered by stacking a SiNx film or a SiNxOy film by the CVD method. Alternatively, the core may be removed by flattening or polishing.

4 (k) or (l), heat treatment is performed to solidify the fluid adhesive 67 and fix the core 71 and the magnetic shield 70. Thereafter, the magnetic shield is removed from the bonding agent 69, and the support substrate 68 is also removed. For example, polyimide is used as the flowable adhesive 67 and solidified to some extent at a temperature of about 150 ° C. A material whose adhesiveness is reduced at 150 to 250 ° C. is used as the bonding agent 69, and then heated at 150 to 250 ° C. to separate the core 71 and the magnetic shield material 70 from the support substrate 68. Thereafter, the main heat treatment is performed at about 300 ° C. to completely solidify and stabilize the polyimide. For example, there is a thermoplastic adhesive as a material whose adhesiveness decreases as the temperature rises.

FIG. 4M shows a state of the silicon substrate 51 after the support substrate 68 is separated. The core 71 enters the coil center hole 66 and is fixed. Further, the magnetic shield material 70 is adhered and fixed on the solidified fluid adhesive 70.
Next, as shown in FIG. 4N, an insulating film 72 is stacked to cover the core 71 and the magnetic shield 70. Since the core 71 and the magnetic shield 70 are magnetic bodies, they may be deteriorated by moisture when they come into contact with the outside air. Moreover, since the fluid adhesive 67 may also absorb moisture, it is necessary to cover it with the insulating film 72. As the insulating film, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film formed by a CVD method is desirable. A process for opening the pad electrode may be performed after this. The electrical characteristics of the semiconductor device on which the inductor is mounted can be measured using the opened pad electrode.

FIG. 6 is still another example in the first embodiment of the present invention. FIG. 6A shows a semiconductor device formed on the semiconductor substrate 91. The semiconductor substrate 91 is a single element semiconductor such as silicon or germanium, a binary compound semiconductor such as gallium arsenide or indium phosphide, a substrate such as a ternary semiconductor, or a bonded substrate such as SOI (Silicon On Insulator), carbon. Also includes substrates. Further, the substrate includes a wafer. A large number of semiconductor chips are formed on a semiconductor substrate, and each semiconductor chip is used as a semiconductor device or semiconductor device as an IC or individual semiconductor for a wide range of applications such as communication, processor, memory, image processing, and power supply. Used as a device. The semiconductor device shown in FIG. 6A is intended for all semiconductor devices using the inductor of the present invention. FIG. 6 (a) shows only the part necessary for explaining the inductor of the present invention and the manufacturing method thereof, but other semiconductor elements such as active elements such as transistors, passive elements such as resistors and capacitors, and the like. A circuit, wiring, etc. including these are also formed.

6A, an insulating film 92 exists on a semiconductor substrate 91, and electrodes / wirings 93 (93-1 to 93-5) are formed thereon. The electrode / wiring 93-1 is an electrode / wiring connected to one terminal of the inductor of the present invention, and its upper surface is opened. The electrode / wiring 93-2 is an electrode / wiring connected to the other terminal of the inductor of the present invention, and its upper surface is opened. Although the opening is numbered 95, the opening 95-1 is the opening of the electrode / wiring 93-1, and the opening 95-2 is the opening of the electrode / wiring 93-2. The electrode / wiring 93-3 is provided under a portion serving as a coil central hole in order to block an electromagnetic field generated in the coil.

The electrodes / wirings 93-4 and 93-5 are provided under a portion around the coil wiring in order to block an electromagnetic field generated in the coil. Electrodes and wirings 93-3 to 5-5 are electrodes. It also functions as an etching stopper when etching the insulating film 94 on the wiring. When the materials of the electrodes and wirings 93-3 to 93-3 are the same as those of 93-1 and 93-2, they can be formed at the same time as the formation of 93-1 and 03-2. It will not be up. However, in order to enhance the effect of the magnetic field shield, a material having a high magnetic permeability is good, and therefore, a material different from 53-1 and 53-2 may be used. In addition, when there is no need to shield the electromagnetic field, and when there is not much effect, it is not necessary to provide 93-3-5. In order to shield the electromagnetic field, it is better to cover the coil wiring as much as possible. Therefore, it may cause short circuit with other electrodes / wiring, or cracks in the insulating film, affecting the electrical characteristics and reliability. It is better to cover as much area as possible.

Next, as shown in FIG. 6B, a seed layer 96 is stacked. The seed layer 96 is a conductor, particularly a metal film, but is preferably the same material as the plating metal because it serves as a starting point for plating. For example, when performing copper plating, it is good to use copper or a copper alloy. When the material of the seed layer 96 has poor adhesion to the insulating film 96 and the electrode / wiring 93 or when the characteristics deteriorate due to a reaction due to subsequent heat treatment or the like, the seed layer 96 is deposited after the barrier metal is laminated. Are laminated. This barrier metal also improves the bonding with the electrode / wiring 93. For example, when the electrode / wiring 93 is aluminum or an aluminum alloy and the seed layer 96 is copper or a copper alloy, titanium (Ti), TiN, TiW, tantalum (Ta), tantalum nitride (TaN), Tantalum tungsten (TaW) or the like is stacked. The thickness of the electrode / wiring 93 is 0.3 μm to 2 μm, the thickness of the barrier metal is 0.01 to 0.5 μm, and the thickness of the seed layer is 0.1 to 2 μm. The seed layer and / or the barrier metal are laminated by sputtering, vapor deposition, or CVD.

Next, as shown in FIG. 6C, a photoresist 97 is formed on the seed layer 96. The photoresist may be formed by coating, or a photosensitive film may be attached on the semiconductor substrate 91. Next, as shown in FIG. 6D, a portion 98 where the coil wiring is formed is opened by an exposure method. For example, the window opening portion 98-1 is a coil wiring forming portion where the coil wiring is connected to the electrode / wiring 93-1 on the semiconductor device side, and the window opening portion 98-2 is a coil wiring forming portion. The portion 98-3 is a coil wiring forming portion where the coil wiring is connected to the other electrode / wiring 93-3 on the semiconductor device side. The depth of the window opening portion 98 is set to be equal to or smaller than the thickness of the coil wiring. For example, when forming a coil wiring having a thickness of 10 μm, the thickness of the resist 97 is set to about 10 μm or more. Since the thickness of the coil wiring determines the value of the inductance of the coil, the depth of the window opening portion 98, that is, the thickness of the photoresist or the dry film 97 can be determined. The photoresist or dry film 97 may be photosensitive polyimide or other photosensitive polymer, photosensitive resin, photosensitive film, or photosensitive solder resist.

Next, as shown in FIG. 6E, a plated metal 99 is grown based on the seed layer 96 exposed at the window opening portion. When the plating metal is copper, for example, the semiconductor substrate is immersed in a copper sulfate solution, and the electric field is applied between the semiconductor substrate as one electrode and the other electrode. Although the plating layer 99 having a predetermined thickness is grown, it is not preferable to grow it to a depth greater than the depth of the window opening portion 98 (resist thickness) because it grows in a mushroom shape on the plating ceiling portion. The plating is generally wet, but the metal film 99 can also be grown using dry plating, that is, selective CVD.

Next, as shown in FIG. 6F, when the photoresist 97 is removed by a wet method or a dry method (ashing), the seed layer 96 without the plating layer 99 is exposed. Next, as shown in FIG. 6G, the seed layer 96 is etched. This etching is a whole surface etching of the semiconductor substrate 91. Etching methods include dry etching and wet etching. In the wet etching, when the seed layer is copper, the semiconductor substrate 91 is immersed in an etching solution such as sulfuric acid-hydrogen peroxide solution or iron chloride, or the etching solution is sprayed on the semiconductor substrate 91 or sprayed. And etching. When the barrier metal is laminated, the barrier metal is thinner than the seed layer, so that it can often be etched with the same etching solution as the seed layer. For example, when titanium is used as the barrier metal when the seed layer is copper, titanium can also be etched with the above-described wet etching solution. Since the etching is performed in the state of FIG. 6F, the plating layer 99 is naturally etched when the seed layer 96 is being etched. In the case of the same material as the seed layer 96, even if the formation methods of the seed layer 96 and the plating layer 99 are different, the etching rates of the two are not so different, but if they are greatly different, the plating layer 99 is extremely etched, or Since the seed layer is extremely etched and becomes a mushroom-like shape, it is important to select an etching solution and set conditions. Further, when a barrier metal is present, care must be taken so that the plating layer 99 and the seed layer 96 are not etched too much when the barrier metal etching rate is lower than the seed layer etching rate. Alternatively, there is a relentless caution to prevent wrinkling when the barrier metal etching rate is high. As described above, since the plating layer is also etched when the seed layer 96 is etched, the thickness of the plating layer is determined in consideration of the etching amount. For example, if the seed layer thickness including the barrier metal is 1 μm and the etching amount of the seed layer including the barrier metal is 1.2 μm including over-etching, the total thickness of the coil wiring is 10 μm. For example, the thickness of the plating layer may be about 10.2 μm. The coil wiring is formed as described above.

Next, as shown in FIG. 6H, a photosensitive polyimide film 100 is applied. After pre-baking after application, the coil center hole 101 is opened by an exposure method as shown in FIG. Further, the peripheral portion of the coil is simultaneously opened by the exposure method. A magnetic material is also inserted into the polyimide opening 102 (102-1, 102-2), and serves as an electromagnetic shield. After opening the polyimide openings 101 and 102, heat treatment is performed to cure and stabilize the polyimide. By using the photosensitive polyimide film as described above, the insulating film and the photoresist can be used together, so that not only the material cost can be saved but also the process can be simplified. Pre-baking before exposure is often performed at 80 to 120 ° C. The final heat treatment condition of the polyimide film is performed at about 250 to 500 ° C., although it varies depending on the reliability level. The heat treatment temperature after this process is also taken into consideration.

Next, as shown in FIG. 6J, the insulating film 94 on the electrode / wiring 93 is etched in the openings 101 and 102 of the polyimide film 100. Etching methods include a wet etching method and a dry etching method. When the insulating film 94 is a silicon oxide film, it can be etched with a hydrofluoric acid solution in the case of wet etching, and a fluorine gas such as CF4 and C4F8, a CHF gas such as CHF3 in the case of dry etching, There are SF gases such as SF6. Since the electrode / wiring 93 serves as an etching stopper, the electrode / wiring 93 is not etched much even if some over-etching is performed. Further, since the entire surface of the semiconductor silicon substrate 91 is etched, the polyimide film 100 is also etched, so that the thickness of the polyimide film 100 on the coil wiring 99 is reduced. Therefore, the thickness of the polyimide film 100 is determined in consideration thereof. There is a need. Further, since the thickness of the polyimide film 100 is reduced by the heat treatment, the thickness of the polyimide film 100 is determined in consideration of the reduced amount.

Next, as shown in FIG. 6K, a fluid adhesive 101 is applied. The fluid adhesive 101 is in a liquid state in use. The fluid adhesive 101 is dropped onto the semiconductor substrate 91, for example, and the semiconductor substrate 91 is spun and applied onto the semiconductor substrate 91 uniformly. The dents are thick and the convex parts are thin. For example, as shown in FIG. 6 (k), the polyimide openings 101 and 102 are thick, and the coil wiring 99 is thin. If the characteristics are not good when the fluid insulating film 101 is directly formed on the electrode / wiring 93 or the polyimide film 100, the film is thinly formed using the CVD method or the PVD method before applying the fluid adhesive 101 (for example, , 0.1 μm to 2 μm) insulating films (SiOx, SiNx, SiOxNy films, etc.) may be laminated. On the other hand, the magnetic thin plate 105 and the columnar magnetic body 104 are patterned and attached to the support substrate 107 via the bonding layer 106. The magnetic body 104-3 becomes a core of coil wiring. The magnetic bodies 104-1 and 104-2 surround the outside of the coil wiring 99. The magnetic thin plate 105 covers the upper part of the core wiring 99. The magnetic bodies 104-1 and 104-2 are patterned so that they can be inserted into the polyimide openings 102-1 and 102-2 of the semiconductor substrate 91. The core 104-3 is patterned so that it can be inserted into the coil center hole 101.

The alignment mark or actual pattern of the support substrate 107 is accurately aligned with the alignment mark or actual pattern of the semiconductor substrate 91 to bring both substrates close to each other so that the core 104-3 moves to the coil center hole 101 and the magnetic body 104-1. , 104-2 are inserted into the polyimide openings 102-1 and 102-2, respectively.
Next, as shown in FIG. 6 (l), after the insertion is completed, the fluid adhesive 104 is solidified, and the magnetic bodies 104-1 to 104-3 and the magnetic thin plate 105 are fixed. Further, the magnetic layer 105 is separated by softening the bonding layer 106 and reducing the adhesive force. This state is shown in FIG. Thereafter, as shown in FIG. 6 (n), similarly to the case shown in FIG. 5 (n), an insulating film 106 can be stacked to protect the magnetic bodies 104-1 to 104-3. As shown in FIG. 6 (n), the coil in the present embodiment has one turn in the vertical direction and one turn in the horizontal direction (planar direction) (more precisely, as can be seen from the case shown in FIG. 5 (b)). About one and a half turns), and a magnetic core is contained in the center of the coil. Therefore, the inductance increases by the permeability compared to the case without the core (air core coil). In the present invention, for example, Fe, Co, Ni, which are ferromagnetic materials having very high magnetic permeability, and alloys thereof can be used for the core of the coil wiring, so that a high-performance coil can be produced. For example, if a thin plate of permalloy (Fe—Ni alloy) is used as the core, the magnetic permeability is about 20000 or more. Therefore, if the size is the same, an inductance about 20000 times or more that of the air-core coil can be obtained. The size can be reduced to 1/20000 or less. Also, the Q value can be greatly improved. Furthermore, in the present embodiment, since the coil wiring is surrounded by the magnetic material, the electromagnetic field can be shielded, so that a high quality coil is obtained. In addition, since the process is very simple, the fabrication is easy and the process stability is very high. In addition, since a coil (inductor) can be easily connected and incorporated in a normal semiconductor device, a very small semiconductor device with an inductor is obtained. Moreover, what has insulation, such as a ferrite, can also be used as a magnetic body. In that case, since it is an insulator, it can be brought close to the coil wiring, or even when it comes into contact with the coil wiring, there is an advantage that electricity does not flow from the coil wiring.

FIG. 7 is a modification of the manufacturing method shown in FIG. Since FIGS. 7A to 7J are the same as FIGS. 6A to 6J, the description thereof is omitted. As shown in FIG. 7 (j), the coil center hole 101, the polyimide openings 102 (102-1, 102-2), and the insulating film 94 on the electrodes / wirings 93 in these openings are also removed.

Next, as shown in FIG. 7K, the support substrate 110 to which the patterned magnetic bodies 112 (112-1 to 112-3) are attached is brought close to the semiconductor substrate 91 while performing pattern matching. If the support substrate 110 is a transparent glass substrate, light can be transmitted through the glass substrate 110 and pattern matching with the semiconductor substrate 91 can be performed. If the support substrate 110 is a substrate opaque to light, such as a silicon substrate, a ceramic substrate, or a metal substrate, pattern matching using reflected light can be performed. Alternatively, alignment can be performed using electromagnetic waves, infrared rays, ultraviolet rays, X-rays, or the like that pass through the support substrate, or alignment can be performed through a through hole formed in the support substrate 110 corresponding to the alignment mark of the semiconductor substrate 91. Become. In any case, it is possible to match the support substrate 110 and the semiconductor substrate 91 with very high accuracy. Since the support substrate 110 can be brought close to the semiconductor substrate 91 in the vertical direction with high accuracy, the patterned magnetic body can be inserted into the polyimide opening with high accuracy. Further, since the vertical movement distance can be controlled to 0.1 μm even at present, the magnetic substance can be attached to the semiconductor substrate 91 without any problem.

As can be seen from FIG. 7 (k), in the embodiment in FIG. 7, the adhesive 113 (113-1 to 113) is formed on the bottom surface of the magnetic body 112 (112-1 to 112-3) without using the fluid adhesive. -3) is adhered. Various attachment methods are conceivable. For example, there is a method in which the bottom surface of the magnetic body 112 attached to the support substrate is immersed in an adhesive solution for attachment. The adhesive 113 is, for example, a thermosetting adhesive. For example, there are epoxy resins, acrylic resins, and phenol resins. Alternatively, a conductive adhesive can also be used.

Moreover, in FIG. 7, the magnetic body for electromagnetic shielding which connected the magnetic body 112 is not used. This is because the gap (space) 114 generated between the openings 101 and 102 and the magnetic body 112 (112-1 to 112-3) cannot be filled when this electromagnetic shielding magnetic body is used. When the magnetic body 112 comes into contact with the electrode / wiring 93 via the adhesive 113, the approach of the support substrate 110 to the support substrate 91 is stopped. This state is shown in FIG. As can be seen from this figure, the support substrate 110 is prevented from contacting the polyimide 100 which is the uppermost portion of the semiconductor substrate 91. The reason for this is to prevent damage to the polyimide 100 or the semiconductor device when contacted. For this purpose, the thickness of the magnetic body 112 is adjusted so that it is slightly above the upper surface of the polyimide film 100 that is the uppermost portion of the semiconductor substrate 91.

Thereafter, heat treatment is performed to cure the adhesive 113 and fix the magnetic body 112 to the electrode / wiring 93. Thereafter, the adhesive force of the bonding agent 111 is weakened, and the magnetic body 112 is separated from the support substrate 110. For example, a material that softens at a temperature higher than the temperature at which the adhesive 113 is cured and has a low adhesive force may be used for the bonding agent 111. For example, there is a thermosetting resin. FIG. 7 (m) shows this state. That is, the magnetic body 112-3 enters the coil center hole 101 and is fixed on the electrode wiring 93-3. The magnetic bodies 112-1 and 112-2 are fixed on the electrodes / wirings 93-1 and 93-2 so as to surround the periphery of the coil. If the conductive adhesive is used, the magnetic body 112 and the electrode / wiring 93 are electrically connected, so that the performance of the electromagnetic field shield is improved. In addition to this, the purpose of removing the insulating film 94 on the electrodes / wiring may be to lower the position of the bottom surface of the magnetic body 112 as much as possible so that the coil wiring can be covered in the height direction. Since the coil of the present invention has extremely good performance, the insulating film 94 does not have to be removed by etching if it is not necessary to achieve this. Without this etching step, the process is further simplified.

Next, as shown in FIG. 7 (n), an insulating film 115 is formed to fill the gap (space) 114, and the magnetic body 112 is covered and protected by an insulator. A fluid insulating film such as polyimide or SOG is relatively difficult to fill a narrow gap (space) 114. In that case, it is preferable to form the insulating film by a CVD method. In order to improve moisture resistance, a nitrogen-containing film such as a SiNx film or a SiNxOy film is desirable.

As described above, the core can be arranged around the coil central hole and the coil wiring also by the method shown in FIG. In this case, since there is no magnetic body on the ceiling, the effect of the electromagnetic shield is slightly weaker than that shown in FIG.

FIG. 8 is a diagram for explaining a patterning method by attaching a magnetic material to a support substrate. As a material for the support substrate, glass, ceramic, silicon, metal plate, or the like can be used. Although it is the same size as the size on the semiconductor substrate side, it may be larger or smaller. The shape of the semiconductor substrate is not necessarily the same. Since the semiconductor substrate is usually a disc (circular in plan), the same shape is preferable in consideration of alignment, but it may be rectangular or elliptical. In short, for a semiconductor substrate on which a large number of coils need to be formed, a magnetic material such as a core can be inserted from the support substrate into the coil central hole and / or the opening around the coil with a single operation. is required. However, it does not exclude a method of mounting a magnetic body in a step-and-repeat method (same as a stepper) by reducing the support substrate.

As shown in FIG. 8A, a bonding agent 122 is formed on a support substrate 121, and a thin magnetic plate is attached. As the magnetic material, a material having a desired magnetic permeability is selected. That is, this material is determined by the inductance of the inductor, the size of the inductor, the number of turns of the coil, the resistance of the coil wiring, and the like. For example, various materials such as permalloy, ferromagnetic Fe, Co, and Ni are available as materials having high magnetic permeability. As can be understood from the above description, the thickness of the magnetic body is approximately the same as the depth of the coil central hole. Recently, a very thin thin plate having a thickness of 10 μm or less can also be formed. In the present invention, it can be used in a state where it is attached to a support substrate. After pasting through the bonding agent 122, the entire surface may be etched to reduce the thickness, or may be polished by a grinder to reduce the thickness. By using a CMP (Chemical Mechanical Polishing) method, it is possible to obtain a magnetic material having a precise thickness.

Instead of attaching a magnetic thin plate, it may be formed on the support substrate using PVD (physical vapor deposition) or CVD (chemical vapor deposition) such as sputtering or vapor deposition. At this time, it is laminated on the bonding agent 122. In the case of a sputter, a magnetic material is used as a target, and a tag gate is sputtered with an inert gas such as Ar and stacked on a support substrate. Since the thickness can be controlled at the nanometer level, a magnetic material having an accurate thickness can be formed on the support substrate.
As the bonding agent 122, a material whose bonding force is lost or weakened by heat treatment or ultraviolet irradiation is used. For example, a thermoplastic resin or a metal such as solder. As described above, the magnetic body needs to be firmly attached to the support substrate 121 until the magnetic body is bonded to the semiconductor substrate side. As a method of separating the magnetic material from the support substrate 121 after the magnetic material 124 is firmly bonded to the semiconductor substrate, the softening temperature and melting point of the bonding agent 122 are higher than the curing temperature of the adhesive that bonds the magnetic material to the semiconductor substrate side. Use something. There are many resins and metals in such combinations, and a better one can be selected from them. For example, a thermosetting resin that solidifies at 250 ° C. or lower may be selected as an adhesive that adheres to the semiconductor substrate side, and a thermoplastic resin that softens at 300 ° C. or higher may be used as the bonding agent 122.

Next, as shown in FIG. 8B, a photoresist is applied (or a photosensitive dry film is pasted, and a photoresist or the like is applied on the portion where the magnetic material is to be left by an exposure method (pre-baking, developing, post-baking, etc. Then, the magnetic material is etched using the photoresist as a mask, as shown in Fig. 8C. There are wet etching and dry etching, for example. In the case of iron, dry etching using chlorine gas, etc. Further, dry etching can also be performed by mixing CO gas and NH 3 gas.In the case of wet etching, dilute sulfuric acid, dilute hydrochloric acid, or secondary chloride is used. In the case of wet etching or isotropic dry etching, a photoresist mask may be used. Since the etching side surface is tapered and the etched side surface is tapered (that is, the width on the photoresist side is reduced), a coil center hole or the like can be produced in consideration of the tapered shape. The coil center hole, etc. is also tapered so that the taper shape can be inserted smoothly (taper shape with a wide opening top (insertion side) and a narrow bottom of the opening). The taper-shaped magnetic pattern smoothly enters even with holes close to 1. In the case of anisotropic dry etching, a pattern close to the shape of the photoresist 124 can be obtained, and the size can be easily controlled. The same ferromagnetic material and permalloy can also be etched.

Next, the photoresist is removed to obtain magnetic patterns 123 (123-1 to 123-3) as shown in FIG. In this way, the magnetic pattern 123 can be formed on the support substrate. Note that the bonding agent 122 in the portion without the magnetic material may be left or removed. Since the thickness of the bonding agent may be about 0.1 μm to 10 μm, particularly when the bonding agent is thin, there is a possibility that the bonding agent may not be scraped off during etching (particularly during dry etching). Absent.

FIG. 9 is a diagram for explaining a method of manufacturing a support substrate in the case of having a magnetic shield material. As shown in FIG. 9A, the bonding agent 132 is attached on the support substrate 131. The bonding agent 132 is attached for application or by a sticking method. On top of that, a material to be the magnetic shield material 133 is laminated or adhered. Since the magnetic shield material is more effective as a material having a high magnetic permeability, the magnetic shield material 133 is preferably a material having a high magnetic permeability. Therefore, the same material as the material of the magnetic body to be laminated or adhered thereafter may be used. Of course, different materials may be used with high magnetic permeability. Next, a magnetic thin plate 134 is laminated or adhered. The magnetic shield material 133 and the magnetic body 134 may be laminated by a PVD method or a CVD method.

Next, as shown in FIG. 9B, a photoresist pattern 135 is formed by photolithography. Next, as shown in FIG. 9C, the magnetic body 134 is etched using the photoresist 135 as a mask, and the magnetic bodies 134 (134-1 to 134-3) are patterned. When the magnetic shield material 133 and the magnetic body 134 are different materials, the etching rate differs to some extent. Therefore, the etching rate difference is used to prevent the magnetic shield material 133 from being etched excessively. Even when the same material is used, the etching is discontinuous at the boundary between the magnetic body 134 and the magnetic shield material 133, so that the magnetic shield material can be prevented from being etched excessively.

Next, after the etching of the magnetic body 134 is completed, the photoresist 135 is removed to obtain a pattern of the magnetic body 134 (134-1 to 134-3) as shown in FIG. Next, as shown in FIG. 9E, in order to pattern the magnetic shield material 133, the photoresist 136 is formed into a desired pattern, and as shown in FIG. 9F, this photoresist 136 is used as a mask. Then, the magnetic shield material 133 is etched. Thereafter, the photoresist 136 is removed, and the magnetic shield 133 can be formed in a desired pattern as shown in FIG. In this manner, the pattern of the magnetic body 134 (134-1 to 134-3) and the pattern of the magnetic shield 133 can be produced.

FIG. 10 is a diagram for explaining another method for producing a support substrate having a magnetic shield material. As shown in FIG. 10A, a magnetic body 143 made of the same material as the magnetic shield material is attached or laminated on the support substrate 141 via a bonding agent 142. Next, as shown in FIG. 10B, patterning is performed with a photoresist or a photosensitive dry film (144). The magnetic material 143 is etched by a desired amount using the patterning 144 as a mask. The magnetic body 143 is left as much as the magnetic shield (indicated by 145). Thus, as shown in FIG.10 (c), the magnetic body pattern 143 (1433-1 to 143-3) is formed. FIG. 10D is a view after the photoresist 144 is removed. Next, as shown in FIG. 10E, a photoresist 146 is patterned in order to form a portion to be a magnetic shield material. Next, as shown in FIG. 10F, the magnetic shield material 145 is etched using the photoresist 146 as a mask to obtain a pattern 145-1 having a desired shape. Thereafter, the photoresist 146 is removed, and the magnetic shield 145-1 can be formed in a desired pattern as shown in FIG. Thus, the pattern of the magnetic body 143 (143-1 to 143-3) and the pattern of the magnetic shield 145 (145-1) can be produced using the same magnetic material.

FIG. 11 is a diagram showing a third embodiment of the present invention. The figure shown in FIG. 11 shows the structure of a semiconductor device equipped with the inductor of the present invention. Based on FIG. 11, a manufacturing method of the inductor shown in the third embodiment will be described. Electrodes / wirings 503 are formed on an insulating film 502 formed on the semiconductor substrate 501. Reference numeral 503 (503-1, 503-2) denotes electrodes / wirings to which inductor terminals are connected.

An insulating film 504 is formed on the electrode / wiring 503 and a part of the electrode / wiring 503 is opened. The electrode / wiring 503 is connected to the inductor (coil) wiring through the opening 505 (505-1, 505-2). Next, the coil wiring 506 is laminated. In order to improve the quality of the coil, it is preferable to increase the Q value. In order to increase the Q value, it is preferable to decrease the resistance of the coil wiring. If the material of the coil wiring is the same, the cross-sectional area of the coil wiring may be increased. The size may be increased in the lateral direction to increase the thickness. In order to increase the thickness, there is a method in which the conductor film is grown thickly by PVD or CVD. However, if the thickness is 5 μm or more, it takes time and the productivity is deteriorated. The plating method is the same, and plating of 20 μm or more takes time. Therefore, in the third embodiment, the coil wiring is also prepared in advance on the support substrate, and the coil wiring attached to the support substrate is attached to the semiconductor substrate. The coil wiring attached to the support substrate is referred to as a thick coil wiring 508 and is distinguished from the coil wiring 506 laminated on the semiconductor substrate 501 described above.

The laminated coil wiring 506 is patterned, connected to the electrode / wiring 503 (503-1, 503-2), and formed in an annular shape so as to wind a place where a core is to be disposed in the future. Next, the thick coil wiring 508 attached to the support substrate is attached to the patterned coil wiring 506. An adhesive 507 is attached to the bottom of the thick coil wiring 508 attached to the support substrate, and the thick coil wiring 508 is attached to the coil wiring 506 through the adhesive 507. Since the thick coil wiring 508 and the coil wiring 506 need to be electrically connected, the adhesive 507 is a conductive adhesive. Alternatively, a metal or alloy having a low melting point may be used. As a method of forming the thick coil wiring 508 on the support substrate, the same method as the method of attaching the magnetic material described above can be used. For example, a conductor thin plate having a predetermined thickness is attached to the support substrate. The bonding agent at this time is a thermoplastic (thermosoftening) adhesive or the like. The pasted conductor film is patterned into a large number of coil wirings so that the semiconductor substrate 501 can be mounted. This patterned coil wiring is a thick coil wiring 508. The material of the coil wiring 506 and the material of the thick coil wiring 508 may be the same or different. The coil wiring 506 may be cut off halfway. Subsequent conduction is not a problem because electricity flows through the thick coil wiring 508. The thick coil wiring 508 is attached to the coil wiring 506 via the adhesive 507, and is heat-treated at a temperature equal to or higher than the curing temperature of the adhesive to fix the thick coil wiring 508 to the coil wiring 506. Thereafter, the thick coil wiring 508 and the support substrate are separated from each other by raising or lowering the adhesive strength of the bonding agent that joins the thick coil wiring 508 to the support substrate to eliminate or weaken the adhesive.

Next, an insulating film 509 is stacked to cover the coil wiring 506 and the thick coil wiring 508. Next, the patterned magnetic body 511 attached to the support substrate is inserted into the internal space (coil central hole) of the coil, and the internal space (coil center) of the coil is passed through the adhesive 510 attached to the bottom of the magnetic body 511. Adhere to the bottom of the hole). The method for separating the magnetic body 511 from the support substrate is the same as described above. Next, an insulating film 512 as a protective film is laminated to cover the magnetic body 511. Also in the third embodiment, the fluid adhesive and the photosensitive insulating film described above can be used. In the present invention, when an insulating film is laminated by the CVD method or the PVD method, the thick coil wiring 508 and the coil wiring 506 are laminated with a conformal coverage. Since the coil center hole close to the shape of these coil wirings is formed, the magnetic body 511 can be easily inserted.

Next, an example of another support substrate to which a magnetic material is attached is shown. The upper part of the semiconductor substrate has various irregularities, so that the support substrate does not come into contact with the uppermost part of the irregularities of the semiconductor substrate during a series of processes in which the magnetic substance is inserted into the semiconductor substrate, attached and separated. Must be. In particular, a support substrate that can be used even when the thickness of the magnetic material is small and smaller than the depth of the central hole will be described. As shown in FIG. 12A, a bonding agent 152 is attached on the support substrate 151. In consideration of the thickness of the magnetic material to be inserted and the depth of the central hole of the coil wiring to be inserted (including the polyimide opening), the thickness of the bonding agent 152 does not contact the support substrate 151 with the pattern on the semiconductor substrate. To be determined. For example, the thickness of the magnetic material is 2 μm, the depth of the coil wiring center hole is 2.1 μm, the thickness of the adhesive adhering to the bottom of the magnetic material is 0.1 μm, the maximum variation is 0.3 μm, the support substrate In order to prevent the support substrate 141 from coming into contact with the pattern on the semiconductor substrate, when the margin in the vertical direction of the semiconductor substrate is 0.2 μm, the flat portion of the support substrate (where there is no magnetic material) ) Must be 2.5 μm or more. In this case, the thickness of the bonding agent 152 is 0.5 μm or more.

The bonding agent 152 is preferably a material whose adhesive strength is lowered at a certain temperature or more like a thermoplastic polymer. Therefore, a metal or alloy having a melting point within a processable range may be used. Or an inorganic substance may be sufficient. You may adhere by the apply | coating method and you may adhere a sheet-like thing. Next, the magnetic body 153 is attached on the bonding agent 152. Next, as shown in FIG. 12B, a photoresist 154 is formed in a desired pattern by photolithography.

Next, the magnetic body 153 is etched using the photoresist 154 as a mask, and the bonding agent 152 is also etched. The bonding agent may be completely etched, or the etching may be terminated halfway when a predetermined depth is obtained. Moreover, even if the bonding agent 152 is etched, the depth still seems to be insufficient, and the AREVA and the support substrate 151 may also be etched. If the pattern of the magnetic material 153 is excessively side etched, the shape may change and the characteristics may change. Therefore, it is better to suppress side etching as much as possible (in addition, as described above, side etching may be actively performed). However, since the bonding agent and the support substrate are finally unnecessary, if the magnetic body 153 is firmly fixed to the support substrate, there is no problem with some side etching.

FIG. 12D is a diagram showing a pattern formed on the support substrate after the photoresist 154 is removed. Both the magnetic body 153 and the bonding agent 152 are patterned, and the distance from the bottom of the magnetic body (although it is above) to the support substrate is larger than the thickness of the magnetic body 153 by the thickness of the bonding agent 152. Yes. If this distance is necessary, the thickness of the bonding agent 152 may be increased or the support substrate 151 may be further etched. As a result, the magnetic substrate 153 can be inserted into, attached to, and fixed to the central hole of the coil wiring and the polyimide opening, and the magnetic substrate can be separated from the support substrate 151 without contacting the support substrate with the pattern of the semiconductor substrate. Alternatively, the bonding agent 152 can be left on the semiconductor substrate side, softened and melted, and poured into the gap or space between the magnetic bodies to fill the gap or space.

FIG. 13 is a diagram showing a fourth embodiment of the present invention. In this embodiment, coil wiring and a core are produced in advance on a support substrate. That is, an inductor with a core is formed on a support substrate, and the inductor with a core is attached to a semiconductor device (device) manufactured on a semiconductor substrate. In FIG. 13, until the coil wiring is formed on the semiconductor substrate, it is the same as in the case of FIG. That is, the coil wiring 506 is laminated on the semiconductor substrate 501 and patterned into a desired shape.

On the other hand, the coil wiring 523 is formed on the support substrate 521 with the bonding agent 522 interposed. The coil wiring 523 may be formed by attaching a coil wiring formed on a separate substrate in the same manner as in the present invention, or by laminating the bonding agent 522 on the support substrate 521 or by laminating a thin plate of the coil wiring. It may be pasted or patterned to form coil wiring after that. In the former case, the pattern of the magnetic body 524 is formed on the support substrate 521. As the formation method, the above-described method may be used. Next, a patterned coil wiring 523 (523-1, 523-2) formed on another substrate is attached. The adhesive used at this time (referred to as adhesive A) is a thermosetting resin. A bonding agent in which the separate substrate and the coil wiring are bonded is referred to as a bonding agent B. The bonding agent B is a thermoplastic resin. The curing temperature of the adhesive A is TA, and the softening temperature of the bonding agent B is TB. Select a resin such that TA <TB. When the coil wiring 523 is attached and fixed to the support substrate, heat treatment is performed at a temperature between TA and TB. Next, heat treatment is performed at TB or higher to separate the coil wiring from another substrate. At this time, since it is not good if the bonding agent 522 on the support substrate 521 is softened, a material whose softening temperature TC of the bonding agent 522 is higher than TB is used.

In the latter case, a coil wiring pattern is formed on the support substrate 521. Next, a patterned magnetic body 524 formed on another substrate is attached. The adhesive (adhesive D) used at this time is a thermosetting resin. A bonding agent in which the separate substrate and the magnetic body 524 are bonded is referred to as a bonding agent E. The bonding agent E is a thermoplastic resin. The curing temperature of the adhesive D is TD, and the softening temperature of the bonding agent E is TE. A resin that satisfies TD <TE is selected. When the magnetic body 524 is attached and fixed to the support substrate, heat treatment is performed at a temperature between TD and TE. Next, heat treatment is performed at TE or higher to separate the coil wiring from another substrate. At this time, since it is not good if the bonding agent 522 on the support substrate 521 is softened, a material whose softening temperature TC of the bonding agent 522 is higher than TE is used.

After arranging the coil wiring 523 and the magnetic body 524 on the support substrate 521 as described above (the magnetic body 524 is a core and enters the inside of the coil wiring), a photosensitive resin (for example, photosensitive Polyimide) is applied and patterned so as to cover the outside of the coil wiring 523. Thereafter, the photosensitive resin is cured by heat treatment at a temperature higher than the curing temperature of the photosensitive resin. Although the coil wiring is mounted on a plurality of support substrates, there is no photosensitive resin between the coil wirings at this stage, and the bonding agent 522 is exposed as shown in FIG. Next, the coil wiring 523 of the support substrate 521 and the side where the magnetic material is present (the front side of the support substrate 521) are polished to expose the surface of the coil wiring 523. Alternatively, the entire surface is etched back to remove the resin on the surface of the coil wiring 523. The surface of the magnetic body 524 may also be exposed, but if it is not desired to be exposed, the height of the magnetic body may be set lower than the coil wiring. At this stage, it is completed as a single coil or inductor. This coil has a core 524.

Next, a conductive adhesive is attached to the exposed surface of the coil wiring 523. This state is shown in FIG. In FIG. 13, the magnetic core 524 is inserted inside the coil wiring 523 (523-1, 523-2). A photosensitive resin is cured and buried between the coil wiring 523 and the magnetic body 524. Further, the outer side of the coil wiring 523 is covered with a cured photosensitive resin 526. When it is not desired to directly contact the coil wiring 523 or the magnetic body 524 with the photosensitive resin 526, a protective film 525, for example, a SiOx, SiNx, or SIOxNy film is formed by a CVD method before the photosensitive resin 526 is formed (applied). You may laminate. A conductive adhesive 527 is attached to the surface of the coil wiring 523. The conductive adhesive 527 may be a metal such as solder or an alloy. A portion other than the vicinity of the surface of the coil wiring 523 is removed by using a photolithography method. In FIG. 13, the conductive adhesive 527 is illustrated to be slightly larger than the surface of the coil wiring 523, but it is necessary to be surely connected to the underlying coil wiring 506. However, it should not be so large that short-circuit characteristics cannot be obtained or reliability deteriorates. Or you may apply | coat an anisotropic conductive adhesive to the whole surface, or may affix a sheet-like thing.

As shown in FIG. 13, thereafter, the support substrate 521 is further lowered, and the coil wiring 506 and the coil wiring 523 are bonded. In the case of the anisotropic conductive adhesive, since current flows in the vertical direction, electricity is conducted between the coil wiring 506 and the coil wiring 523 without any problem, and since electricity flows in the horizontal direction, there is no short circuit. Further, when the magnetic core 524 is exposed, it is covered with resin, so that it also functions as a protective film. The curing temperature TF of the conductive adhesive is set lower than the TC of the bonding agent. In this way, by performing heat treatment at TF or more and TC or less, first, the coil wiring 523 is fixed to the semiconductor substrate 501, and then heat treatment is performed at TC or more to separate the coil wiring 523 and the magnetic body 524 from the support substrate 521. To do. At this time, a part of the bonding agent 522 remains on the semiconductor substrate 501 side, but this bonding agent 522 also serves as a protective film because it covers the coil wiring 523 and the magnetic material. However, if it is desired to be removed, the entire surface can be removed by dry etching. In order to further protect the magnetic body 524 and the coil wirings 523 and 506, an insulating film may be laminated by a CVD method or a PVD method. The silicon nitride film is the best for improving the moisture resistance.

FIG. 14 is a modification of the third embodiment. In this embodiment, bump electrodes 534 are formed on the electrodes on the semiconductor substrate 501 side, and bump electrodes 537 are formed on the terminals of the coil wiring on the support substrate 521 side. These bump electrodes 534 and 537 are joined. In FIG. 13, 506 is a coil wiring, but in this embodiment, it is a rewiring layer. Since the purpose is slightly different from 506 in FIG. The rewiring layer 530 is connected to the electrode / wiring 503. An insulating film 531 is stacked on the rewiring layer 530, and connection pads 532 to the outside of the rewiring layer 530 are opened. A seed metal 533 is stacked in the opening 532. A seed layer 533 and a bump metal 534 are formed by a semi-additive method, an additive method, or a subtractive method. The bump metal 534 is formed by a plating method, but can also be formed by a printing method or the like. Although the rewiring 530 is formed on the semiconductor substrate 501, in the present invention, only the inductor is connected. it can. In that case, the process is simplified. When plating is not used, for example, when the bump is formed by a printing method, the seed layer 533 may not be necessary.

Next, on the support substrate side, the same method as shown in FIG. 13 can be used until the coil wiring 523 and the magnetic core 524 are formed. Thereafter, a protective film may be formed at 525 to cover the coil wiring 523 and the magnetic core 524 as in FIG. Next, a photosensitive resin 526 is applied to fill the gaps existing between the coil wirings 523 and between the coil wirings 523 and the magnetic core 524 and flatten the surface to some extent. This is also the same step as that in FIG. 13, but after this, pre-baking is performed, and further, a surface portion 535 between the coils and the surface of the coil wiring is opened by an exposure method. After opening, post-baking and main baking are performed to cure the photosensitive resin. Next, a seed layer 536 is stacked, and a bump metal is formed in the opening of the coil wiring 523. Thus, an element as a single inductor is formed. On the support substrate 521, a plurality of inductors (which may be said to be a large number) are mounted. A magnetic core is inserted in each.

Next, the support substrate 521 is brought close to the semiconductor substrate 501 while being aligned, and the bump 534 on the semiconductor substrate 501 side and the bump 537 on the support substrate side are brought into contact with each other. When the bumps 534 and 537 are solder metal, they are simply joined by heat treatment at a temperature close to the melting point of the solder metal with a flux interposed therebetween. In the case of copper bumps or gold bumps, bonding is performed by heating while applying a little pressure, but it is also effective to apply ultrasonic waves. If bonding is difficult even with the above method, a conductive adhesive may be interposed between the bumps. In this case, the conductive adhesive may be applied to the heads of both bumps, but either one may be used. Alternatively, the conductive adhesive sheet may be sandwiched between the bumps for thermocompression bonding. The conductive adhesive is not limited to resin and may be solder metal. That is, bonding can be achieved by attaching molten metal to the bump head and thermocompression bonding to the other bump. If these operations are carried out in an inert gas atmosphere or in a vacuum, metal oxidation and the like can be prevented.

Next, the bonding agent 522 is softened to separate the inductor from the support substrate. If the bonding agent 522 uses an electromagnetic wave such as ultraviolet rays that loses or weakens the adhesive ability, the bonding agent 522 is separated by irradiation with electromagnetic waves such as ultraviolet rays. In this case, a support substrate that transmits the electromagnetic wave is selected. When the bonding agent is a thermoplastic resin or metal, the one whose softening temperature or melting point is close to the temperature at which the bump is bonded is selected, and the support substrate is separated at the same time as the bump is bonded. Alternatively, there is a method in which a support substrate having a good thermal conductivity is selected and the adhesive strength of the bonding agent 522 is weakened in a short time. In the case of a thermosetting conductive adhesive, a bonding agent that softens at a temperature higher than the curing temperature of the conductive adhesive may be selected.

In the embodiment shown in FIG. 14, bumps are formed on both the inductor side and the semiconductor device side, but if only one side can be bonded, only one of them may be used. For example, convex bumps can be formed only on the other side when it can be easily joined to the electrode metal or electrode conductor exposed in the opening on the other side. Further, the support substrate may be a semiconductor substrate, an insulating substrate, or a metal substrate, as in the other embodiments. A substrate that is easy to align with the counterpart substrate and that can be accurately aligned is preferable. There must be as little warpage as possible in order to achieve accurate alignment.

In the present invention, since a core with high magnetic permeability can be inserted, a very large inductance can be obtained. However, if the coil wiring is formed in a spiral shape, the number of turns of the coil wiring can be easily increased. Further, it is possible to obtain a larger inductance. In addition, since the resistance of the coil wiring can be easily lowered by changing the material or the size, the quality (Q value) of the inductor can be greatly improved. In other words, inductors with the same inductance and Q value are very small in size.

The inductors described so far are such that the core is perpendicular to the surface of the semiconductor substrate, and the coil wiring is wound around the core. The coil wiring is spirally formed on the surface of the semiconductor substrate (that is, spirally). In the case where the cores are rotated in parallel (or the core is spirally wound (that is, spirally wound in the height direction)). This is called a vertical inductor in the sense that the core stands vertically (perpendicular) to the semiconductor surface. On the other hand, a case where the core lies on the side of the semiconductor substrate surface will be described. This is called a horizontal inductor.

FIG. 15 is a diagram showing a basic structure of the lateral inductor of the present invention. FIG. 15A is a plan view of the lateral inductor of the present invention, and FIG. 15B is a cross-sectional view thereof. (However, since all the relevant parts are shown in the sectional view of FIG. 15 (b), those in the foreground and those in the back are also shown.) In FIG. Only the part is shown. Since the horizontal inductor of the present invention can be easily incorporated into a semiconductor substrate, it can be formed in the semiconductor substrate simultaneously with the semiconductor device in the same manner as the vertical inductor. For example, in an LSI having a two-layer Al wiring, the lower coil wiring 603 can also be used as the first-layer Al wiring, and the upper coil wiring 606 can also be used as the second-layer Al wiring. However, when the core 604 is thick, the insulating film between the first and second coil wirings must be thickened, so there are cases in which fine vias between Al wirings cannot be formed (the aspect ratio of the vias is large). Become). At that time, the upper coil wiring 606 is formed as another wiring. At that time, since a new process must be added to connect the coil wiring 606 to the second-layer Al wiring of the LSI, the lower coil wiring 603 and the first-layer Al wiring of the LSI are connected. (The coil wiring 603 is also a first-layer Al wiring. Alternatively, the coil wiring 603 is contacted to an LSI diffusion layer or wiring (PolySi, etc.) or via a via to the second-layer Al wiring. May be connected)

As can be seen from FIG. 15B, the coil wiring 603 (603-1) is provided in the insulating film 602 on the semiconductor substrate 601, and the magnetic core 604 is provided thereon. The coil wiring 603 is connected to the coil wiring 606 on the core 604 through the contact hole 605. A conductor film is laminated in the contact hole. The coil wiring 606 crosses the core 604 and is connected to the next contact hole 607. A conductive film is present in the contact holes 605 and 607. In some cases, this conductor film can also be used as the upper layer coil wiring 607. However, when the aspect ratio of the contact hole becomes large and the upper layer coil wiring 607 does not sufficiently enter the contact hole, the upper layer coil wiring 607 is used. Formed separately. (For example, a conductive film is embedded.) The contact hole 607 is connected to the coil wiring 603-2 adjacent to the coil wiring 603-1. By repeating this, the coil wiring is formed in a spiral shape while winding the core 604 with the lower layer coil wiring 603, the contact hole 605, the upper layer coil wiring 606, and the contact hole 607. This state is easy to understand when viewed in plan in FIG. Wirings parallel to the paper surface indicated by thick solid lines are lower layer wirings 603 (from the front, 603-1 to 603-4). Above that is the core 604, shown in broken lines. The wiring indicated by the slanted thin lines is the upper layer coil wiring 606 (from the front, 606-1 to 606-5). The right contact hole 605 (605-1 to 605-4 from the front) and the left contact hole 607 (from the front, 607-1 to 607-4) are connected to the lower layer coil wiring 603 and the upper layer coil wiring 606. . The core 604 is covered with the insulating film 2 and is not in contact with the coil wirings 603 and 606 and the contact holes 605 and 607. In the present invention, the core attached to the support substrate is inserted and arranged while being aligned with the semiconductor substrate. An insulating film is formed on the upper coil wiring 606, and further, connection electrodes / wirings 610 (610-1, 2) to the outside are formed thereon. The external connection electrodes / wirings 610 (610-1, 2) are connected to the upper coil wiring 606 through the contact holes (608, 609). As a result, the connection electrode / wiring 610 (610-1) to the outside passes through the conductor film (usually the same as the connection electrode / wiring 610) in the contact hole 608, and the upper coil wiring 606 (606-1). ) Enters the contact hole 605 (605-1), passes through the lower layer coil wiring 603 (603-1), enters the upper layer coil wiring 606 (606-2) from the contact hole 607 (607-1), and enters the contact hole 605. (605-2) passes through the lower layer coil wiring 603 (603-2), enters the upper layer coil wiring 606 (606-3) from the contact hole 607 (607-2), and contacts the contact hole 605 (605-3). The lower layer coil wiring 603 (603-3) passes through the contact hole 607 (607-3) and the upper layer coil wiring 606 (606-4) passes through. From the hole 605 (605-4) through the lower layer coil wiring 603 (603-4), from the contact hole 607 (607-4) through the upper layer coil wiring 606 (606-5), and from the contact hole 609 to the outside Connection electrode / wiring 610 (610-2) is connected. If you want to increase the number of turns, just repeat this connection.

As can be seen from this basic form shown in FIG. 15, in the case of a horizontal inductor, the coil wiring has two layers, and the core is sandwiched therebetween. The lower coil wiring and the upper coil wiring are connected by a contact hole. Therefore, the number of turns of the coil can be easily increased, and the inductance is proportional to the square of the number of turns, and thus becomes very large. In addition, since the high magnetic permeability core of the present invention is inserted, an inductor (coil) having a very large inductance can be manufactured by a simple process. An outline of a method for manufacturing a horizontal inductor is a method for manufacturing an inductor with a core in which a coil wiring is wound in a spiral shape with a core inside, and is formed on a first substrate which is a semiconductor substrate, an insulating substrate, or a conductive substrate. A step of forming one coil wiring, a step of forming a first insulating film, a step of attaching a core attached to the second substrate to the first substrate, and a step of separating the second substrate from the core And a step of laminating a second insulating film, a step of forming a connection hole for connecting the first wiring and the second wiring in a spiral shape, and a step of forming a second coil wiring. . The second substrate may also be a semiconductor substrate, an insulating substrate, or a conductive substrate such as a metal or a conductive material. Further, electronic circuits such as semiconductor devices and ICs may be formed on the first semiconductor substrate, and the inductor of the present invention may be connected to them.

FIG. 16 is a diagram illustrating a method for manufacturing a horizontal inductor.
An insulating film 712 (first insulating film) is formed over a semiconductor substrate 711 which is a first substrate. The insulating film is a silicon oxide film (SiOx), a silicon nitride film (SiNx), a silicon oxynitride film (SiOxNy), or the like, and is generated by a CVD method, a PVD method, or the like. Alternatively, an inorganic insulating film or an organic insulating film formed by a coating method may be used. In the case of a coated insulating film, an appropriate heat treatment is performed. A conductor film 713 is stacked on the insulating film 712. The conductor film is made of conductive PolySi (PolySi doped with P, B, As, etc.), metal film such as Al, Cu, Ti, Cr, W, metal silicide film, alloys thereof, or conductor films thereof. It is a composite membrane. This conductor film is referred to as a first conductor film.
The first conductor film 713 is formed in a desired pattern by photolithography. For example, a pattern in which rectangular shapes (cuboid shapes) as shown in FIG. The first conductor film 713 is a lower wiring (603 in FIG. 15) of the coil.

Next, a second insulating film 714 is stacked. The insulating film is a silicon oxide film (SiOx), a silicon nitride film (SiNx), a silicon oxynitride film (SiOxNy), or the like, and is generated by a CVD method, a PVD method, or the like. Alternatively, an inorganic insulating film or an organic insulating film formed by a coating method may be used. In the case of a coated insulating film, an appropriate heat treatment is performed. Alternatively, a composite film of these insulating films may be used. If flattening is required, the surface is flattened with a coating insulating film or polished by CMP or the like. Alternatively, an etch back method is used. The thickness of the insulating film on the conductor film 713 is set to a desired thickness. For example, the thickness is set such that the magnetic film 716 formed thereon is not electrically conductive.

Next, an adhesive layer 715 is laminated, and portions other than the desired portion are removed. On this adhesive layer 715, a patterned magnetic film 716 attached on the support substrate 718 is aligned and attached. The adhesive layer 715 may be bonded in advance on the magnetic layer 716 (in this case, on the bottom surface) and may be bonded to a predetermined place of the insulating film 714 as it is. When the magnetic layer 716 and the insulating film 714 can be directly bonded by heat treatment or the like, the adhesive layer 715 is unnecessary.
For example, as the insulating film 714, an organic coating film (for example, a polyimide film or an organic SOG film) or an inorganic coating film (for example, an SOG film) may be used. In the case of a coating film, the magnetic layer 716 is placed in the coated state, and the magnetic layer 716 is slightly embedded in the coating film, and then the coating film is solidified to fix the magnetic layer 716. Alternatively, heat treatment is performed at a temperature lower than the temperature at which the coating film is completely solidified, and the magnetic layer 716 is placed and pressed a little while the coating film is softened. Then, heat treatment is performed to solidify the coating film, and the magnetic layer 716 is fixed. Note that in the case where a coating film is directly bonded to the conductor film 713 and there is a concern about reliability or the like, the coating film may be applied after thinly depositing an insulating film by a CVD method or the like. As the adhesive layer 715, for example, an organic coating film or an inorganic coating film is applied, (such an adhesive to be applied is called a fluid adhesive), and after heat treatment (pre-baking), the magnetic film 716 is bonded, Further, it may be fixed by heat treatment (main baking). Alternatively, the magnetic film 716 may be directly bonded to the coating film without pre-baking and then fixed by heat treatment. Thus, when the adhesive layer 715 is an insulating film, it does not conduct with other conductors, and thus the adhesive layer 715 may not be patterned. Further, in the case of a fluid adhesive, the surface unevenness is filled, so that the insulating film 714 does not have to be planarized. (Of course, it may be flattened.)

As a method of forming the adhesive layer 715 on the magnetic film 716 in advance, the upper part (bottom part in the drawing) of the patterned magnetic film 716 is immersed in an adhesive solution so that the adhesive is attached onto the magnetic film 716. Then, after pre-baking, the insulating film 714 may be bonded. Pre-baking is not necessary. After the bonding, the main body is baked to fix the magnetic body 716 to the insulating film 714 through the adhesive layer 715.

As described for the vertical inductor, when the magnetic film 716 is adhered to the support substrate 718 with the adhesive layer 717, for example, the adhesive layer includes a thermoplastic (thermosoftening) resin or a metal (alloy such as solder). ) Adhesive layer. The softening temperature (or melting temperature) or melting point is T5. When the adhesive layer 715 is a thermosetting resin adhesive layer, the curing temperature is T6. The magnetic film 716 attached to the support substrate 718 through the adhesive layer 717 is attached to the adhesive layer 715, and heat treatment is performed at a temperature higher than the temperature T6 and lower than T5, thereby firmly fixing the magnetic film 716 to the adhesive layer 715. . After fixing, the magnetic film 715 can be separated from the support substrate by performing heat treatment at a temperature of T5 or higher. When the magnetic film 716 is attached to the support substrate 718 by vacuum suction or electromagnet without using the adhesive layer 717, there is no temperature restriction.

Next, a third insulating film 719 is stacked. (The insulating film 712 is the first insulating film, and the insulating film 714 is the second insulating film.) The insulating film is a silicon oxide film (SiOx), a silicon nitride film (SiNx), a silicon oxynitride film (SiOxNy), or the like. It is generated by CVD method, PVD method, etc. Alternatively, an inorganic insulating film or an organic insulating film formed by a coating method may be used. In the case of a coated insulating film, an appropriate heat treatment is performed. Alternatively, a composite film of these insulating films may be used. If flattening is required, the surface is flattened with a coating insulating film or polished by CMP or the like. Alternatively, an etch back method is used.

Next, a via hole (contact hole) 720 is formed in a predetermined portion by photolithography. The via hole 720 is a contact hole that connects the lower wiring 713 and the upper wiring (606 in FIG. 15 or 722 in FIG. 16C) in a spiral. A metal film is laminated on the contact hole 720 by a CVD method, a PVD method, or a plating method. Alternatively, a conductor film may be formed by a coating method (for example, a conductor paste is applied). Examples of the metal film include aluminum, Cu, Ti, Cr, solder, W, Mo, or an alloy thereof, a metal silicide film, or a composite film thereof. The via hole 720 may be completely filled, but may not be filled if there is no problem. This 721 is called plug wiring.

Here, the size and aspect ratio of the via hole (contact hole) 720 are estimated. Symbols shown in FIG. 19C are used. The thickness of the insulating film on the lower wiring 713 is p3 (this is equal to the depth of the contact hole), the thickness of the insulating film between the magnetic film 716 and the lower wiring 713 is q3, and the thickness of the magnetic film 716 is r, where u3 is the thickness of the insulating film on the magnetic film 716, p3 = q3 + r + u3. Since q3 and u3 are sufficient if they are 0.5 μm or more, they are each set to 1 μm. p3 = 4 + r (μm). When the thickness of the magnetic film is 1 μm, p3 = 5 μm. If the wiring width of the lower wiring 713 and the upper wiring 722 is 5.5 μm, the contact hole size can be 5 μm {5 μm * 5 μm (can be made larger in the longitudinal direction of the wiring)}. Then, the aspect ratio of the contact hole is about 1.0, and the PVD method (for example, sputtering method) or the CVD method can be sufficiently stacked on the contact hole with good coverage. (Therefore, the contact hole conductor film can also be used as the upper second conductor film.)

The insulating film 719 may be a photosensitive resin (for example, a photosensitive polyimide film). In the case of a photosensitive resin, it is applied on the semiconductor substrate 711 by a coating method. Alternatively, a photosensitive film may be used. After the photosensitive resin is applied, it is pre-baked and a contact hole 720 is opened by an exposure method. Thereafter, this baking is performed to cure the photosensitive resin, whereby an insulating film 719 is obtained. When the photosensitive resin is used, the photolithography process is not necessary, and the photosensitive resin can be used as it is as the insulating film 719. Since the insulating film 714 exists at the bottom of the opened contact hole 720, the insulating film 714 at the bottom of the contact hole 720 is removed by dry etching or wet etching. In order to prevent side etching of the insulating film 714, dry etching, particularly anisotropic etching is preferable. Note that the insulating film 714 can also be formed of a photosensitive resin. At this stage, if the contact hole 720 is formed by an exposure method (a series of window opening methods using exposure including development), the insulating film in this portion is insulated. Since the film 714 is lost, etching is unnecessary or only a short etching time is required. (Since a foreign substance may be formed on the coil wiring 713 in the contact hole 720 or the adhesive 715 may enter in the subsequent processing, it may be necessary to remove these.) When using a photosensitive resin When it is not desired to directly contact the photosensitive resin with the coil wiring 713 or the magnetic body 716, an insulating film may be laminated by a CVD method or a PVD method before forming the photosensitive resin. In this case, it is necessary to remove the insulating film after opening the contact hole 720 by an exposure method.

If an insulating film is attached to the lower part of the magnetic film 716, the magnetic film 716 can be directly attached to the lower conductive film (first conductive film) 716. For example, it can be realized by a simpler process like the method shown in FIG. FIG. 21 is a diagram showing one process in the horizontal inductor according to the present invention. As shown in FIG. 21A, an adhesive insulating film 787 is attached to the lower part of the magnetic film 716. As a method of attaching the adhesive insulating film 787 to the magnetic body 716, for example, the magnetic film 716 is immersed in the liquid body of the adhesive insulating film with the magnetic film 716 attached to the support substrate 718 (in particular, magnetic Then, an adhesive insulating film 787 is attached to the bottom of the magnetic film 716. In order to increase the adhesion of the adhesive insulating film attached to the bottom of the magnetic film 716, light heat treatment, light irradiation, or the like may be performed.

Next, the support substrate 718 and the substrate 711 are brought close to each other, and the magnetic film 716 is attached to the magnetic film 713 through the adhesive insulating film 787. If a substrate that transmits light of a specific wavelength (width) is used as the support substrate (for example, a transparent glass substrate, a quartz substrate, or a transparent plastic), the light of the specific wavelength (width) is irradiated from above the transparent glass substrate. Since the distance from the substrate 711 can be measured optically accurately (with accuracy on the order of nm or less), the adhesive insulating film 787 can be reliably attached to the first conductor film 713. Further, since the adhesive insulating film 787 is soft at this stage, the distance between the support substrate 718 and the substrate 711 can be accurately controlled, and the thickness of the adhesive insulating film 787 can also be accurately controlled. Next, heat treatment is performed to cure the adhesive insulating film 787 to fix the magnetic film 716 to the substrate 711 side, and then the magnetic layer 716 is separated from the support substrate 718 at a temperature higher than the softening point of the adhesive layer 717. . This state is shown in FIG.

Next, as shown in FIG. 21C, an insulating film 788 is stacked by a CVD method, a PVD method, or a coating method. After that, a photosensitive insulating film 789 is applied and prebaked, or a sheet-like photosensitive insulating film is applied and softened to perform planarization. The subsequent process is as described above or later. Even if the photosensitive insulating film 789 is directly laminated on the first conductor film 713 and the magnetic Tama region 716, the insulating film 788 is not necessary if there is no problem in reliability and characteristics. As described above, the process is further simplified by attaching the adhesive insulating film to the magnetic film 716.

When an organic coating film (for example, polyimide film) is used as an insulating film, the process can be further simplified. FIG. 18 is a diagram for explaining an embodiment of a method for manufacturing a horizontal inductor according to the present invention. In FIG. 18A, the process up to the formation of the first conductor film 713 is the same as that described in FIG. An organic coating film 760 is thickly applied on the conductor film 713. The magnetic film 716 adhering to the substrate 718 is inserted into the applied liquid organic coating film 760, and the magnetic film 716 is inserted to a predetermined position and stopped while maintaining the distance between the substrate 718 and the substrate 711. In this state, as shown in FIG. 18D, heat treatment is performed to cure the organic coating film and fix the magnetic film 716. Thereafter, the substrate 718 is separated from the magnetic body 716 by lowering the adhesive force of the adhesive layer 717 by raising the temperature higher than the heat treatment temperature. As described above, there are various other methods. Here, it is important that the substrate 718 is not in contact with the solidified insulating film 760. This is because when the substrate 718 is in contact with the insulating film 760, the substrate 718 and the insulating film 760 are also attached. That is, the distance between the bottom surface of the magnetic film 716 and the conductor film 713 is q (the same as the thickness of the insulating film 760 under the magnetic film 716), the thickness of the magnetic film 716 is r, and the adhesive layer 717 When the thickness is s and the thickness of the solidified insulating film 760 on the conductor film 713 is p, the organic coating film 760 is thickly applied on the conductor film 713 so that p <q + r + s. For example, if q = 1.0 μm (q is sufficient if a thickness of 0.1 μm), r = 5 μm, and s = 2 μm, p <8 μm.

FIG. 18C shows a view after the substrate 718 is separated. Although the adhesive layer 717 remains, the adhesive layer 717 may be separated together with the substrate 718. Considering the case where the adhesive layer 717 remains, it is necessary to select a material that does not affect the device characteristics and reliability. There are many materials, for example, the materials described above. Further, since the adhesive layer 717 is softened or melted, the surface of the insulating film 760 is flattened. However, if unevenness remains, it may be flattened with a coating insulating film, or flattened by an etch back method or a CMP method. Next, as shown in FIG. 18D, an insulating film 762 is formed. The subsequent process is the same as in FIG.

If a photosensitive insulating film (for example, a polyimide film) is used as the insulating film, the process is further simplified. FIG. 19 is a diagram for explaining a process in which the photosensitive film 770 is used on the first conductor film 713 to be the lower layer coil wiring. As shown in FIG. 19A, after the first conductor film 713 is formed, a photosensitive film 770 is applied (the thickness of the photosensitive film 770 after application is p0). The substrate 718 with the patterned magnetic film 716 attached is brought close to the substrate 711. As shown in FIG. 19B, the magnetic film 716 is completely infiltrated into the photosensitive film 770. The substrate 718 is also in contact with the photosensitive film 770. The movement of the substrate 718 is stopped when the distance between the first conductor film 713 and the magnetic film 716 reaches q1. (And / or the movement of the substrate 711 toward the substrate 718 is also stopped.)

In this state, the magnetic film 716 is separated from the substrate 718. If the magnetic film 716 is attracted to the substrate 718 with an electromagnet mounted in the substrate 718, the magnetic film 716 moves away from the substrate 718 if the function of the electromagnet is stopped. Alternatively, if the magnetic film 716 is vacuum-adsorbed by the substrate 718 and the vacuum is released, the magnetic film 716 is separated from the substrate 718. In order to evacuate only the pattern of the magnetic film 716, a mask for adsorbing the magnetic film 716 is previously attached to the substrate 718, or a vacuum drawing hole for adsorbing the magnetic film 716 is formed on the substrate 718. Just keep it. Alternatively, the magnetic film 716 is attached to the substrate 718 using an adhesive layer that eliminates or weakens the adhesive force with special light such as ultraviolet rays or electromagnetic waves, and special light such as ultraviolet rays at the stop position q1. Alternatively, the magnetic film 716 may be separated from the substrate 718 by irradiation with electromagnetic waves. In this case, the substrate 718 is made of a material that transmits special light such as ultraviolet rays or electromagnetic waves, and the photosensitive film 760 is made of a material that is not affected by the special lights such as ultraviolet rays or electromagnetic waves.

In FIG. 19B in which the substrate 718 and the substrate 711 are stopped, if the thickness of the photosensitive film 770 on the first conductor film 713 is p1, then p1 = q1 + r. If there is no adhesive layer between the substrate 718 and the magnetic film 716, p1 is also the distance between the substrate 718 and the first conductor film 713. If the substrate 718 is formed of a material that transmits light for distance measurement, the measurement light can be applied from above the substrate 718 to optically measure the distance s between the substrate 718 and the substrate 711. Since this distance s can be measured very accurately (angstrom level), if the distance when the substrate 718 and the substrate 711 are stopped is s1, the substrate 718 and the substrate 711 are stopped very accurately when s = s1. Can do. (This state is described with the optical measuring device 772 and the measuring light 773 in FIG. 19B.) Here, the material of the photosensitive film and the wavelength and intensity of the measuring light so that the photosensitive film 770 is not affected by the measuring light. Must be selected. (It goes without saying that this method can be applied to other examples and embodiments.)

The magnetic film 716 separated from the substrate 718 in the liquid photosensitive film 770 sinks by its own weight and stops on the first conductive film 713, but as shown in FIG. 19C, the magnetic film 716. And a thin photosensitive film 770 remains between the first conductive film 713 (thickness q2). If the thickness of the photosensitive film on the first conductive film 713 in this state is p2, and the thickness of the photosensitive film 770 on the magnetic film 716 is u2, then p2 = q2 + r + u2, and p2 is substantially equal to p1. Next, as shown in FIG. 19D, pre-baking is performed, and a contact hole 775 is opened in a predetermined portion of the photosensitive film 770 by an exposure method (exposure + development) using a mask. Thereafter, heat treatment (curing heat treatment) is performed to cure the photosensitive film 770. For example, when the photosensitive film 770 is a photosensitive polyimide film (also of various types), prebaking is performed at a temperature of about 100 ° C., and the heat treatment (curing heat treatment) temperature is, for example. The first heat treatment is performed at 150 to 200 ° C., and then the second heat treatment is performed at a temperature of 300 to 400 ° C. After this curing heat treatment, the thickness of the photosensitive film 770 on the first conductor film 713 is p3, the thickness of the photosensitive film 770 between the first conductor film 713 and the magnetic film 716 is q3, and the magnetic material If the thickness of the photosensitive film 770 on the film 716 is u3, p3 = q3 + r + u3. Since the photosensitive film 770 contracts by pre-baking or heat treatment, p3 <p2, u3 <u2, and q3 <q2. When the degree of shrinkage is large, or when u2 is too thin and u3 may be thin (when u3 disappears and magnetic film 716 is exposed), a photosensitive film is applied again. Pre-baking is performed, a contact hole is opened again by an exposure method, and a curing heat treatment is further performed to obtain u3 having a predetermined thickness. Alternatively, in order to secure a predetermined thickness u3 with a single photosensitive film 770, there is a method of controlling the thickness of the photosensitive film 770 so as to secure u2 having a predetermined thickness. If the thickness of u3 is 0.1 μm or more, there is no problem in characteristics, but it is desirable to secure about 0.5 μm or more in consideration of process stability.

If the thickness of q3 is also 0.1 μm, there will be no problem in characteristics, but it is desirable to secure about 0.5 μm or more in consideration of process stability. However, since the magnetic film 716 is submerged in the photosensitive film 770 by its own weight, if the desired thickness cannot be ensured, the second conductive film 713 is formed and then thin (for example, about 0). There is also a method in which a photosensitive film 770 is applied after an insulating film (SiOx, SiNx, SiOxNy, etc.) is laminated by a CVD method or a PVD method. In this case, since the contact hole 775 is formed on the first conductor film after the curing heat treatment after opening the window of the photosensitive film 770, the insulating film is present on the first conductor film. The insulating film is etched. Etching includes wet etching and dry etching. For example, when the insulating film is a SiOx film, wet etching is performed using an HF-based etching solution. However, since the photosensitive film 770 is not etched by this etching solution, side etching of the insulating film SiO2 occurs. So be careful. In the case of dry etching, anisotropic etching is desirable so that side etching of the insulating film does not occur. In the dry etching method, when the entire surface is etched without using a mask, the photosensitive film 770 on the magnetic film 716 is also etched (the etching amount can be reduced by performing etching with high selectivity). Therefore, it is necessary to determine the thickness u3 of the photosensitive film in consideration of that amount. (As described above, if the thickness between the second conductor film and the magnetic film 716 is about 0.1 μm, there is no problem in characteristics, but if the process stability is taken into consideration, the thickness is about 0.5 μm. It is desirable to ensure the above.)

As another method when the desired thickness q3 cannot be ensured, there is a method in which an insulating film is previously laminated under the magnetic film 716 attached to the substrate 718. FIG. 20 is a diagram for explaining the process of one embodiment of the lateral inductor of the present invention. As shown in FIG. 20A, a substrate 718 having a magnetic film 716 on which an insulating film 780 having a predetermined thickness (v1) is stacked is put into a photosensitive film 718, and the first conductive film 713 and When the distance q1 of the insulating film 780 reaches a predetermined value, the movement of the substrate 718 and the substrate 711 is stopped, and the magnetic film 716 is separated from the substrate 718. Thereafter, as shown in FIG. 20C, the first conductor film 713 is approached by its own weight and stops at a distance q2 between the first conductor film 713 and the insulating film 780. Thereafter, as shown in FIG. 20D, a contact hole 775 is formed by an exposure method, and a curing heat treatment is performed. In this embodiment, p1 = q1 + v1 + r in FIG. 20B, p2 = q2 + v1 + r + u2 in FIG. 20C, and p3 = q3 + v1 + r + u3 in FIG. 20D. Therefore, since the insulating film 780 always exists between the first conductor film 713 and the magnetic film 716, there is no need to worry about the electrical connection between the first conductor film 713 and the magnetic film 716. . Even if q2 and q3 become 0, there is no problem. In addition, the process of applying the photosensitive film 770 directly on the first conductive film 713 without applying the photosensitive film 770 after forming the insulating film on the first conductive film 713 can be adopted. . Therefore, it is not necessary to take a process of etching the insulating film after the contact 775 is formed.

There are various methods for forming the insulating film 780 on the magnetic film 716. For example, while the magnetic film 716 is attached to the substrate 718, the tip of the magnetic film 716 (in FIG. 20A, the lower part of the magnetic film 716) is immersed in a liquid insulating film, and the magnetic film The insulating film 780 can be formed on the magnetic film 716 after being attached to the tip portion of 716 and then cured by heat treatment. Further, for example, after attaching a magnetic thin plate to the substrate 718, an insulating film is stacked on the magnetic film (CVD method, PVD method, coating method), and the insulating film and the magnetic film are patterned into a predetermined shape. Thus, an insulating film 780 can be formed on the magnetic film 716 as shown in FIG. This heat treatment may cause a solvent or the like to adhere to the first conductor film 713 exposed in the contact hole or form a foreign substance (the connection may be deteriorated if this is left). Therefore, light etching may be performed before the conductor film is formed in the contact hole. This light etching is reverse sputtering, dry etching, or treatment of acid or organic solution.

Next, as shown in FIG. 16C, a conductor film 722 is laminated thereon and patterned into a desired shape. (This conductor film 722 is the upper wiring in 606 of FIG. 15.) This conductor film 722 can also be formed of the same material as the lower layer wiring 713. The same material or different materials may be used. What is necessary is just to select suitably according to the characteristic of an inductor (coil). The conductor film 722 can also be used as the plug wiring 721. That is, the plug wiring 721 and the conductor film 722 are formed together. (However, if the step coverage (coverability) of the conductor film 722 is not good in the contact hole 720, it is better to form the conductor film 722 after forming the plug wiring 721). From the upper wiring to the plug and the upper wiring, and from the upper wiring to the plug and the lower wiring, the coil wiring can be formed. Since the magnetic body 716 exists in the central portion (inner portion) of the inductor, an inductor having a large inductance and a high Q value can be created. Moreover, since it is manufactured by the LSI method, a fine inductor can be formed with very high accuracy.

Next, as shown in FIG. 16D, an insulating film 723 is formed. This insulating film 723 serves as a protective film for coil wiring. In order to protect the entire coil, the insulating films 719, 714, and 712 on the outside of the coil are removed, and then the insulating film 723 is formed. As the insulating film, SiOx, SiNy, SiOxNy, etc. formed by CVD method, PVD method, organic resin film such as polyimide, inorganic coating film such as SOG, or a composite film thereof. In order to improve reliability such as moisture resistance, an insulating film by a CVD method or a PVD method is preferable, and an SiNy or SiOxNy film by a CVD method is particularly preferable. For example, a SiOxNy film of 0.1 μm to 1.0 μm is laminated on the patterned coil wiring 722 by a CVD method, a photosensitive polyimide is formed on the SiOxNy film, an opening is formed by a photolithography method, and the opening is used as a mask. The opening 724 (724-1, 724-2) can be formed by etching the SiOxNy film. Of course, if only photosensitive polyimide is used, etching is unnecessary. (However, foreign matters (for example, when an outgas component due to heat treatment of the polyimide film is attached or the conductor film 722 is altered during opening or heat treatment) exist on the conductor film 722 exposed in the opening 724). When the contact becomes worse, light etching (wet or dry etching, or reverse sputtering (sputter etching with Ar, etc.)) may be performed.) If a photosensitive resin is not used, the photolithographic method is also used. An opening 724 is formed in the insulating film 723. The opening 724 serves as a pad, and the characteristics of the inductor can be measured with a prober or the like.

In FIG. 16D, the openings 724-1 and 724-2 are described so as to exist on the same coil wiring 722. However, since the coil wiring 722 is formed in a spiral shape, FIG. As can be seen from the above, different coil wirings are formed. That is, the openings 724-1 and 724-2 correspond to both terminals A and B of the coil shown in FIG. By using the present invention, a high-performance inductor element can be mounted on a semiconductor substrate on which a semiconductor device or a semiconductor device is formed, or a high-performance inductor element can be formed on the semiconductor substrate together with a process for forming the semiconductor device or the semiconductor device. A high performance inductor element can be formed. Further, the pad portion 724 can be filled with a conductor (for example, solder paste) to be slightly convex (for example, bump) by screen printing or the like, and can be mounted on a wiring board after being formed into a chip. it can. Thereafter, the semiconductor device is diced to form a chip (divided into individual pieces), and a semiconductor chip on which an inductor is mounted can be obtained. Alternatively, a seed layer or the like can be formed on the pad portion 724 and a bump can be formed by a plating method.
When connecting to other elements (for example, resistors, inductors, capacitors, transistors, ICs, etc.) formed on the same substrate, the lower layer (first) conductor film 713 or the upper layer (second) conductor film In this case, the opening 724 is not required to be formed. Alternatively, the pad portion connected to another element of the same chip shape and the opening (pad portion) 724 can be wire-bonded by wire bonding, or the opening 724 can be re-wired and connected after forming. Also good.

The horizontal inductor element of the present invention (the same applies to the vertical type) can be used alone as an inductor element package with the above structure. For example, it can be diced in a shape as shown in FIG. 16D and mounted on a printed wiring board or IC chip to be used as an inductance element. In this case, the opening (pad part) 724 serves as an external connection electrode. Further, since the periphery of the inductor element is protected by the protective film 723, the inductor element is strong in the external environment and has good reliability. For example, on the periphery of the inductor element along the dicing line, an insulating film (714, 712, etc., part of which is also removed by the substrate 711 at this time) is removed at the time of forming the contact hole 720, or various conductor films If the conductor film is removed at the time of etching, the entire inductor element (except for the substrate 711 side) can be covered with the protective film 723 without any additional process (no load).

Let us estimate the inductance when the horizontal inductor of the present invention is used. The thickness of the coil wiring is 1 μm (0.001 mm), the coil width is 1 mm, the coil height is 5 μm (0.005 mm), the substrate thickness is 0.3 mm, the number of turns is 500 times (wiring pitch is 2 μm, and the coil length is If the core is not inserted, 108.5 μH and a material having a relative permeability of 10,000 (thickness of about 3 μm) are added to 1085000 μH (1.085 H). Although the size of the coil is 1 mm * 1 mm * 0.005 mm (the package size is 1 mm * 1 mm * 0.3 mm), it can be seen that the coil has a very large inductance. In the present invention, the coil size, the number of turns and the core material can be freely selected, so that an inductor having a wide range of inductance can be easily mounted on a semiconductor device. Further, it can be contacted with the outside (for example, connected with a wire bond).

As can be understood from the above-described manufacturing method, the present invention can be formed as a single inductor as described above. Moreover, it can be used as a wafer level package. That is, a large number of the structures shown in FIG. 16D may be arranged on the semiconductor substrate (wafer). When a single inductor is used, it is not limited to a semiconductor substrate such as a silicon substrate, but may be an insulating substrate such as ceramic, glass or quartz, or a metal substrate such as aluminum, copper or magnetic material. In the case of an insulating substrate, the insulating film 712 can be omitted. If this is separated into pieces, a chip inductor can be formed. If the thickness of the substrate is 0.3 mm (the thickness of the inductor itself can be adjusted freely, but if it is 3 μm, it can be ignored compared to the thickness of the substrate). The size is 1 mm * 1 mm * 0.3 mm It becomes a very small and thin chip inductor having a large inductance of 1H. The periphery of the inductor is surrounded by a substrate and an insulating film (protective film), resulting in a very strong package.

FIG. 17 is a diagram for explaining another method for manufacturing a horizontal inductor.
As shown in FIG. 17A, a method of forming a semiconductor substrate 731, an insulating film 732, and a lower wiring 733 is the same as the manufacturing method described in FIG. Next, the insulating film 734 is formed thick. Planarization may be performed. The central portion (or coil inner portion) 749 above the region of the lower wiring 733 is opened by a photolithographic method (referred to as a coil wiring central hole 749), and the central portion above the region of the lower wiring 733 is formed. The insulating film 734 is etched. Etching is stopped leaving a predetermined thickness on the lower wiring 733. Alternatively, the insulating film 735 may be stacked over the lower wiring 733 so as to have a predetermined thickness after the entire etching. At this time, although the lower wiring 733 serves as an etching stopper material, an insulating film exists in a region where the lower wiring 733 is not present (between the wiring 733 and the adjacent wiring 733). There is a possibility that unevenness exists at the bottom of the coil wiring center hole 749. Therefore, the insulating film may be stacked by a CVD method or the like and then flattened by a coating method or an etch back method.
Alternatively, a photosensitive resin (photosensitive polyimide or the like) may be applied as 734, and after prebaking, the central portion 749 of the lower wiring 733 may be opened by an exposure method, and the photosensitive resin may be cured by baking. In this case, since the lower wiring 733 is exposed, an insulating film 735 may be stacked on the lower wiring 733 so as to have a predetermined thickness.

Next, an adhesive layer 736 is attached over the insulating film 735. If the adhesive layer 736 has fluidity, the unevenness of the insulating film 735 at the bottom of the coil wiring center hole 749 is filled at this stage.
Next, the magnetic film 737 is aligned with the recessed portion (coil wiring center hole 749) in the center, and the magnetic film 737 attached to the support substrate 739 is inserted into the coil wiring center hole and attached to the adhesive layer 736. Let The magnetic film 737 is attached to the support substrate 739 through the bonding agent 738. After fixing the magnetic film 737 to the adhesive layer 736, the magnetic film 737 is separated from the support substrate 739.

Next, as shown in FIG. 17B, an insulating film 740 is laminated on the magnetic film 737 having a predetermined thickness. Before forming, there is a slight gap around the recess of the insulating film 734 (between the magnetic film 737 and the side surface of the recessed portion 749 of the insulating film 734). , The gap disappears. However, when the step coverage is poor, a void (cavity) may be formed inside. If there is no problem in reliability and characteristics, the cavity may be left as it is, but the cavity may be filled using a coating method.
In the case where unevenness is present on the upper surface of the insulating film 740, which causes a problem, the surface of the insulating film 740 may be flattened using a coating method, an etch back method, a polishing method, or the like.

Alternatively, after forming the coil wiring center hole 749, a fluid insulating film is applied to fill the coil wiring center hole 749, and the magnetic material attached to the support substrate 739 in the coil wiring center hole 749 in a fluid state. The body film 737 is inserted, and the magnetic film 737 is placed on the insulating film 735 or placed in the fluid insulating film, and the fluid insulating film is solidified to fix the magnetic film 737, and then the adhesive layer 736. A process similar to the above-described process of separating the substrate 739 from the magnetic film 737 by weakening the adhesive property can be employed. According to this process, the adhesive layer 736 is not necessary, and there is no gap generated between the side surface of the coil wiring center hole 749 and the magnetic layer 737. Further, when the magnetic film 737 is submerged by its own weight, the fluid insulating film remains between the magnetic film 737 and the lower wiring 733 due to the viscosity or specific gravity of the fluid insulating film, or the magnetic film 737 Even when an insulating film attached to the lower part (bottom part) is inserted into the fluid insulating film and submerged by its own weight, a sufficient thickness is provided between the magnetic film 737 and the lower wiring 733 together with the fluid insulating film. Thus, the insulating film 735 between the lower wiring 733 and the magnetic film 737 is not necessary, and the process is simplified.

The subsequent processes are the same as those in the manufacturing method shown in FIG. 16, and a contact hole 741 is formed, and a plug wiring 742 is formed in the contact hole 741. Further, as shown in FIG. 17C, an upper wiring metal 743 is formed. If the upper wiring metal is to be protected or insulated, an insulating film 744 may be formed thereafter.

FIG. 22 shows a variation of the manufacturing method of the horizontal inductor shown in FIG. As shown in FIG. 22A, after forming the insulating film 732 and patterning the first conductive layer 733, the insulating film 734 is laminated to form a magnetic film that becomes the core of the coil (inductor). A window is opened in a region 750 including a region to be formed and a region in which a contact hole between the first conductive layer 733 and the upper coil wiring (second conductive layer) is to be formed. In FIG. 17, at least a portion where the magnetic film is to be formed (coil wiring center hole 749) is formed, but in this embodiment, a window in a larger region including a region where a contact hole is to be formed in addition to this region. Open it. This region is called a contact / magnetic film formation region 750. The insulating film 734 may be an insulating film formed by a CVD method, a PVD method, or a coating method, or may be an insulating film that combines these. Next, using a photolithography method, the photosensitive film is patterned, and using this as a mask, the insulating film 734 is etched to form a contact / magnetic film forming region 750. If there is no problem even if a photosensitive liquid coating film is formed on the first conductive layer 733, a photosensitive insulating film (for example, a photosensitive polyimide film) may be applied to form the insulating film 734. In this case, the contact / magnetic film formation region 750 can be formed only by the exposure method (exposure + development). For example, after a photosensitive polyimide film is applied and prebaked at 100 ° C. to 130 ° C., a contact / magnetic film forming region 750 is opened by an exposure method, cured at 150 ° C. to 200 ° C., and 300 ° C. to 350 ° C. The insulating film pattern 734 shown in FIG.

Next, when a photosensitive insulating film (for example, photosensitive polyimide film) 751 is applied, the contact / magnetic film forming region 750 having a window is thickened. The magnetic film 737 attached to the support substrate 739 is inserted into the magnetic film forming region in the contact / magnetic film forming region 750 via the adhesive layer 738. As shown in FIG. 22B, the insertion of the magnetic film 737 is stopped when a part of the magnetic film 737 is immersed. In particular, it is important to stop the liquid photosensitive insulating film 751 so as not to contact the adhesive layer 738. (To be exact, since the liquid photosensitive insulating film 751 is slightly shrunk by pre-baking, it is sufficient that the photosensitive insulating film 751 is not in contact with the adhesive layer 738 after pre-baking.)

In this state, the photosensitive insulating film 751 is pre-baked. This temperature is T13. Since the liquid photosensitive insulating film 751 is slightly hardened by this pre-baking, the magnetic film 737 is also semi-fixed. Since the pre-bake temperature has a certain tolerance (the lower temperature is T11 and the higher temperature is T12), T13 is a temperature close to T11 (T11 = <T13 <T12). Next, pre-baking is performed at a temperature T14 higher than T13 and close to T12 (T11 <T13 <T14 = <T12). When the softening temperature of the adhesive layer 738 is T15, an adhesive having T15 that satisfies T11 <T15 <T14 is used as the adhesive layer 738. When prebaked at T13, the adhesive layer 738 is not softened, so the magnetic film 737 is semi-fixed to the photosensitive insulating film 751 without moving, and the adhesive layer 738 is softened by pre-baking at T14 for the second time. The body film 737 can be separated from the support substrate 739. FIG. 22C is a diagram showing this separated state. The upper part of the magnetic film 737 protrudes above the photosensitive insulating film 751, and the lower part of the magnetic film 737 is buried in the photosensitive insulating film 751.

Even if the magnetic film 737 is separated from the support substrate 739, since the magnetic film 737 is semi-fixed to the photosensitive insulating film 751, it does not move unless a large impact is applied. Next, as shown in FIG. 22D, a photosensitive insulating film 752 (second photosensitive insulating film 752) is further applied on the pre-baked photosensitive insulating film 751, and the entire magnetic film 737 is coated. Cover. Next, this photosensitive insulating film 752 is pre-baked (temperature T15). If the photosensitive insulating film 752 and the photosensitive insulating film 751 are made of the same material, the prebake temperature can be easily managed. However, if they are different materials, a material such that the prebake temperature T15 is T15 <T12 is used.

Next, contact holes 753 are formed in the photosensitive insulating films 752 and 751 by an exposure method. Since the lower photosensitive insulating film 751 has been pre-baked three times, the sensitivity due to exposure may be reduced. In that case, it is necessary to select exposure conditions (including development conditions) different from normal conditions such as increasing the exposure amount. After the contact hole 753 is formed, a curing heat treatment is performed (a heat treatment such as a curing treatment is also performed if necessary) to cure the photosensitive insulating film. When the first conductor film 753 exposed in the contact hole 753 is denatured or foreign matter is attached by the heat treatment at this time, light etching or the like is performed as described above before forming the conductor film 754 in the contact hole. After the removal of foreign matters and the like, a conductor film 754 is formed in the contact hole. Thereafter, as described with reference to FIGS. 16 and 17, a second conductor film is formed.

After the state shown in FIG. 22C (a state where a part of the magnetic film 737 is buried in the pre-baked photosensitive insulating film 751), the first contact hole can be opened by an exposure method. After opening the window, a curing heat treatment is performed (a curing process is also performed if necessary), and the photosensitive insulating film 751 is completely solidified to fix the magnetic film to the photosensitive insulating film 751. A photosensitive film is applied. The second-layer photosensitive insulating film also enters the first contact hole opened by coating, but the second contact hole is opened at the same location as the first contact hole after pre-baking by the exposure method. By this method, the contact hole can be formed only by the exposure method without using etching or the like. In this case, since the exposure is performed twice, a problem of misalignment occurs. However, if the contact hole can be formed slightly larger so as to include the first contact hole when the second contact hole is formed, the first time It is possible to eliminate all of the photosensitive insulating film that has entered the contact hole formed in the contact hole, and the second contact hole (upper layer side) size is larger than the first contact hole (lower layer side) size. The formation of the conductor film 754 is prepared.

As shown in FIG. 22D, when the thickness of the magnetic film 737 and the first conductor film is q5 and the thickness on the first conductor film is u5, the predetermined thickness q5 or u5 is As shown, a magnetic film 737 attached to the support substrate 739 is inserted and pre-baked to ensure an appropriate q4 {FIG. 22 (a) or FIG. 22 (b)}. It is necessary to apply a photosensitive insulating film 752 having a thickness {FIG. 22 (c)}.

FIG. 23 is a diagram illustrating a manufacturing method of one embodiment of the vertical inductor.
As shown in FIG. 23A, an insulating film 102 is formed on a substrate 101 such as a silicon wafer, and a conductor film 102 is further formed to form a pattern 103 (103-1) having a desired shape. . (Because this wiring is the lowermost wiring of the inductor, it is also referred to as the first wiring 103.) The substrate 101 may be a glass substrate, a quartz substrate, a ceramic substrate, or the like. If the heat treatment temperature is not too high, a plastic substrate may be used. If it is a glass substrate, a quartz substrate, or a transparent plastic substrate, it can be observed from the back side of the substrate, and pattern alignment is easy when a through via (hole) to be formed later is formed. Alternatively, a material substrate used for COB such as a polyimide substrate or a glass epoxy substrate may be used. When the substrate is an insulating substrate, the insulating film 102 may not be formed. It is necessary to prevent the conductor pattern 103 (103-1, 103-2) and the substrate from conducting. This conductor pattern 103 (103-2) serves as one electrode of the inductor. The insulating film 102 is a silicon oxide film (SiOx), a silicon nitride film (SiNx), a silicon oxynitride film (SiNxOy), or the like, and is formed by a thermal oxidation method, a thermal nitridation method, a CVD method, a PVD method, or the like. Alternatively, an SOG film or the like may be applied and solidified by heat treatment. Alternatively, an organic insulating film such as a polyimide film or a resist film may be formed and solidified by heat treatment. Or you may laminate | stack combining these insulating films. The conductor film 103 is made of aluminum (Al), copper (Cu), titanium (Ti), tungsten (W), gold (Au), chromium (Cr), nickel (Ni), various silicide films (TiSix, CrSix, Wsix, NiSix or the like) or a composite film of these, etc., and is formed by a PVD method or a CVD method. The pattern of the conductor film 103 is a wiring pattern 103 (103-1, 103-2) that surrounds the core in an annular shape, and its end is an electrode / wiring 103-2. Here, through holes (vias) are formed later from the back surface of the substrate. Of course, the wiring pattern 103 (103-1, 103-2) is connected. The electrode / wiring 103-2 at the end of the wiring pattern 103 is an electrode / wiring 103-3 that extends outward and is connected to an external electrode.

Next, as shown in FIG. 23A, an insulating film 104 is laminated so that the upper and lower inductor (coil) wires 103 and 107 do not conduct except in the contact hole 105. The insulating film 104 is a silicon oxide film (SiOx), a silicon nitride film (SiNx), a silicon oxynitride film (SiNxOy), or the like, and is formed by a CVD method, a PVD method, or the like. Alternatively, an SOG film or the like may be applied and solidified by heat treatment. Alternatively, an organic insulating film such as a polyimide film or a resist film may be formed and solidified by heat treatment. Or you may laminate | stack combining these insulating films. Since the conductor film 103 has already been formed, it is necessary to pay attention to the type of the insulating film 104 and particularly to the process temperature so that the conductor film 103 is not altered during the formation of the insulating film 104 or in the subsequent heat treatment process. . For example, when the conductor film is aluminum (Al), it is necessary to reduce the generation of hillocks and voids and to prevent the occurrence of stress migration.

In the case where the unevenness of the insulating film 104 becomes large due to the underlying wiring pattern 103 and the patterning of the conductor film 107 formed on the insulating film 104 becomes difficult, the insulating film 104 needs to be planarized. For example, the insulating film 104 is flattened by applying and solidifying an SOG (Spin On Glass) film or an organic insulating film, or the insulating film is deposited to a certain extent and polished by the CMP (Chemical Mechanical Polishing) method. Or flatten by applying an SOG or organic insulating film after forming an insulating film by CVD or PVD, or flattening this by CMP or etchback. It can be combined and flattened.

Next, contact holes 105 (105-1, 105-2) are formed in the insulating film 104. This contact hole 105 is a contact hole for establishing electrical connection between the second wiring 107 and the first wiring 103. A photosensitive film is formed, a window is opened at a predetermined location by an exposure method, and the exposed insulating film 104 is etched away using the window to form a contact hole 105. The insulating film 104 is etched by dry etching or wet etching. When the insulating film 104 is a silicon oxide film (SiOx), in the case of dry etching, etching can be performed using an etching gas such as CF (CF4, etc.) or CHF (CHF3, etc.). When the insulating film is a photosensitive insulating film (for example, a photosensitive polyimide film), the contact hole 105 can be formed only by an exposure method (including development), and the process becomes simple. However, in this case, since a thin organic film may be formed on the surface of the conductor film 103 exposed by the heat treatment after the contact hole is formed, it is necessary to perform light etching before forming the conductor films 106 and 107. There is. The contact hole 105-1 is for connecting the inductor (coil) wiring 105 (105-1) and the inductor (coil) wiring 107 (107-1) thereon, but the contact hole 105-2 is an external electrode. To make a connection to.

Next, a conductor film 106 (106-1, 106-2) is formed in the contact hole 105. The first wiring (electrode) 103 and the second wiring (electrode) 107 are connected through the conductor film 106. Therefore, the conductor films 106 and 107 can be used together, but when the conductor film 106 is planarized by the contact hole, they are formed separately. For example, when a metal film or the like is formed only on the contact hole portion by a selective CVD method, or when only a contact hole is plated by a plating method. The conductor films 106 and 107 may be the same conductor film as the first wiring / electrode 103 and an optimum conductor film may be selected as appropriate. Since both the first wiring 103 and the second wiring 107 are inductor (coil) wiring, the core is surrounded by a circular, polygonal, elliptical, or curved ring, and the contact hole 105-1 is connected to the wiring 103-2. And 107-2.

Next, as shown in FIG. 23B, an insulating film 108 is formed on the second wiring 107. This insulating film 108 is also an insulating film similar to the insulating film 104. However, the insulating films do not have to be the same, and different insulating films may be selected as appropriate. Next, contact holes 109 (109-1, 109-2) are formed, conductor films 110 (110-1, 110-2) are formed, and third {inductor (coil)} wiring 111 (111-) is formed. 1-3) are formed by patterning. This content is also the same as in the case of the contact hole 105, the conductor film 106, and the second wiring 107 described above. The second wiring 107 is connected to the third wiring 111-2 via the conductive film 110-1 in the contact hole 109-1 at 107-2, and the third wiring 111 surrounds the core in a ring shape. And connected to 111 (111-1). The electrode / wiring 107-3 connected to the external electrode is connected to the patterned conductor film 111-3 through the conductor film 110-2 formed in the contact hole 109-2.

Next, as shown in FIG. 23C, an insulating film 112 is formed on the third wiring 111. This insulating film 112 is also an insulating film similar to the insulating film 108. However, the insulating films do not have to be the same, and different insulating films may be selected as appropriate. Next, contact holes 113 (113-1, 113-2) are formed, conductor films 114 (114-1, 114-2) are formed, and fourth {inductor (coil)} wiring 115 (115-) is formed. 1-3) are formed by patterning. This content is also the same as in the case of the contact hole 109, the conductor film 110, and the third wiring 111 described above. The third wiring 111 is connected to the fourth wiring 115-1 through the conductor film 114-1 in the contact hole 113-1 at the location 111-1, and the fourth wiring 115 surrounds the core in a ring shape. And connected to 115 (115-2). The electrode / wiring 111-3 connected to the external electrode is connected to the patterned conductor film 115-3 through the conductor film 114-2 formed in the contact hole 113-2.

Next, as shown in FIG. 23D, an insulating film 116 is formed on the fourth wiring 115. This insulating film 116 is also an insulating film similar to the insulating film 108. However, the insulating films do not have to be the same, and different insulating films may be selected as appropriate. Next, in order to form a hole for inserting the core in a region surrounded by the annularly formed inductor (coil) wirings 103, 107, 111 and 115, a photosensitive film 117 is formed, and the hole is formed in the hole. A window 118 of the area to be formed is formed.

Next, as shown in FIG. 23E, the insulating films 116, 112, 108, and 104 existing under the window 118 are sequentially etched. A core insertion hole 119 is formed. Etching is performed halfway through the lowermost insulating film 102. Note that the insulating film 102 may be completely etched to reach the substrate 102. In order for the core to completely enter the center of the inductor (coil) wiring and surround the core, the core insertion hole 119 is formed below the level of the lowermost inductor (coil) wiring, that is, the first wiring 103. Better. If the core falls below the first wiring 103, the inductance value also increases. As will be described later, when a fluid type liquid insulating film is applied and the core is inserted, there is a possibility that the liquid type insulating film may remain at the bottom of the core even if the core is pushed in. Etching may also be performed. In some cases, it is better to etch the substrate. However, when the portion is used for another purpose (for example, a transistor or a resistor is formed), it is natural that the substrate cannot be etched. In this way, the bottom of the core to be inserted can be surely disposed below the level of the first wiring. If it is not desired to directly contact the liquid type insulating film with the substrate, the liquid type insulating film may be applied after the insulating film (SiOx, SiNx, etc.) is formed by the CVD method or the PVD method.

Next, as shown in FIG. 23 (f), when the liquid type insulating film 120 is applied, the liquid type insulating film 120 accumulates in the core insertion hole 119. Examples of the liquid type insulating film include an inorganic coating insulating film (for example, silanol-based {Si (OH) 4}) such as an SOG film and an organic coating insulating film (for example, polyimide, organic SOG film). In this state, the core 134 bonded to the separate substrate 130 via the adhesive layer 132 is put into the core insertion hole 119. If a transparent substrate such as glass, quartz, or transparent plastic is used as the substrate 130, the pattern on the substrate 101 can be seen from above the substrate 130. Therefore, the core 134 and the core insertion hole (hole) 119 are very accurately aligned. The core 134 can be inserted into the core insertion hole 119. The liquid type insulating film 120 accumulated in the core insertion hole 119 is pushed out by the inserted core 134 and pushed outside the insertion hole 119. The adhesive layer 132 is a thermoplastic adhesive layer.

FIG. 23G shows a state where the core 134 is inserted into the core insertion hole 119. The liquid type insulating film 120 remains in the gap between the bottom surface and the side surface of the core insertion hole 119, and the core is buried in the liquid type insulating film 120. The liquid type insulating film 120 existing on the bottom surface of the core insertion hole 119 exists in a compressed state, but the liquid type insulating film 120 is a buffer material between the core 134 and the inductor body (substrate 101 side) ( It also serves as a cushioning material, and removes damage caused by insertion from the core 134 into the inductor body (substrate 101 side). When the depth d1 (the distance from the top surface of the insulating film 116 to the bottom surface of the core insertion hole 119 as described in FIG. 23E) is greater than the core height h, the adhesive layer 132 is a liquid type. The insertion of the core 134 is stopped before or in contact with the insulating film 120 so as not to damage the inductor body (substrate 101 side). The insertion of the core 134 is governed by the accuracy of movement of the substrate 130 with respect to the substrate 101 (and / or the accuracy of movement of the substrate 101 with respect to the substrate 130), but is very accurate by combining mechanical control and electronic control. Can be controlled. (For example, control of about 0.1 μm is possible.) When h is larger than d1, the core 134 is stopped before the bottom of the core 134 reaches the bottom of the core insertion hole 119. The same applies to the case where the core insertion hole 119 enters the substrate 101 side. In this case, since the core enters a place lower than the first wiring 103 of the inductor (coil), a larger inductance can be obtained. .

Next, heat treatment is performed to solidify the liquid type insulating film 120, and the core 134 is fixed in the core insertion hole 119. The solidification temperature of the liquid type insulating film 120 is T1, the heat treatment temperature for solidification in the actual process is T2, and the softening temperature of the adhesive layer 132 is T3. It is important that T1 <T2 <T3. That is, the liquid type insulating film 120 is solidified in a state where the adhesive layer is cured, and the core 134 is fixed in the core insertion hole 119. After the core 134 is fixed to the core insertion hole 199, the core 134 is separated from the substrate 130 by holding the process temperature T <b> 4 at a temperature higher than T <b> 3 and moving the substrate 130 upward with respect to the substrate 101. This state is shown in FIG. Since there are many materials that satisfy T1 <T2 <T3 for the liquid type insulating film 120 and the adhesive layer 132, they may be appropriately selected. For example, an inorganic coating insulating film (silanol-based {Si (OH) 4}) used as the liquid type insulating film 120 is solidified at a temperature of about 350 ° C. to about 400 ° C., and is used as the adhesive layer 132. STAYSTIC (trade name, manufactured by CSPM) softens at about 400 ° C or higher. Therefore, the above conditions are satisfied. Alternatively, for example, an organic insulating film polyimide film (cured at 350 ° C. or higher) can be used as the liquid type insulating film 120.

When the core 134 protrudes from the core insertion hole 119 and protrudes from the uppermost surface 120-1 of the solidified insulating film 120, a liquid type insulating film is further applied and flattened, or etching is performed thereafter. Planarization may be performed by a method or a polishing method. If it does not cause any problems, it can be left as it is. When all the cores 134 enter the core insertion hole 119 (when the surface of the adhesive layer 132 is flat, the entire core 134 rarely enters the core insertion hole 119, but the adhesive layer is thickened only by the portion of the core 134. If the process is performed, the entire core 132 can be inserted into the core insertion hole 119.) is a depression, but may be left as it is if there is no problem in the process. However, if the indented state is a problem in the process, the above-described planarization may be performed.

In FIG. 23 (e), after the core insertion hole 119 is formed, the core 134 is inserted so that the liquid type insulating film 120 is not excessively accumulated in the core insertion hole 119 (that is, thinly applied). May be. In this case, the liquid type insulating film 120 enters between the core 134 and the core insertion hole 119, but the upper part of the core 134 may not be covered with the liquid type insulating film 120. In that case, after the liquid type insulating film 120 is solidified to fix the core 134 and the core 134 is separated from the substrate 130, the liquid type insulating film is applied again to cover the core 134. If necessary, it may be combined with an insulating film formed by CVD or PVD. Further, it may be flattened thereafter.

In FIG. 23 (h), the core 134 having a thickness h enters the core insertion hole 119, the surface is flattened, and the surface of the core 134 is exposed. Thereafter, as shown in FIG. 23I, an insulating film 123 is laminated. This insulating film is an insulating film such as SiOx, SiNx, or SiOxNy, and is formed by a CVD method, a PVD method, a coating method, or a combination thereof. Thereafter, contact holes 124 (124-1, 2) are formed on the fourth {inductor (coil)} wiring 115 (115-1, 3) (or the uppermost coil wiring when the coil wiring is overlapped). Then, a conductor film 125 (125-1, 2) is formed in the contact hole 124, and a conductor film 126 to be taken out to the outside as an electrode / wiring is laminated, and the electrode / wiring 126 (126-1, 162- 2) is formed by patterning. Thus, the electrode 126-1 is spirally connected from the lowermost first coil wiring 103 around the core 134 from the bottom to the top, and the conductor film 125 in the contact hole 124-2 in the uppermost coil wiring 115 is connected. -2 is connected to the other electrode / wiring 126-2 to complete the coil (inductor). The conductor film 125 and the electrode / wiring 126 in the contact hole 124 can be used together. Further, the conductor film 125 and the electrode / wiring 126 in the contact hole are not formed, and the contact hole 124 can be used as a pad opening of the uppermost coil wiring. A bump electrode can also be formed on the electrode / wiring 126 or in combination therewith.

In the embodiment shown in FIG. 23, the electrode / wiring 126-1 connected to the lowermost coil wiring 103 is connected to the uppermost layer without difficulty. Since the contact holes are also formed sequentially, no additional process is added, and the aspect ratio of the contact holes is not high, so there is no problem with the reliability of the wiring. In order to increase the number of turns of the coil (inductor) wiring, the wiring may be overlapped further upward (vertically), or the wiring may be doubled, tripled, or n-folded in the lateral direction (planar) (n = 4, 5, ...) may be increased. By increasing the number of turns, the inductance and Q value can be further increased.

FIG. 24 shows a variation of FIG. As shown in FIG. 24, the inside of the coil wiring is stacked in a plate shape without patterning the wiring. FIG. 24 (a) is similar to FIG. 23 (d), but the inside of the coil wirings 103, 107, 111, 115 is not patterned each time. Absent. In this state, the photosensitive film 117 for forming the core insertion hole 119 is patterned to form a window 118 in a region to be the hole. Next, as shown in FIG. 24B, a core insertion hole 119 is formed using this as a mask. At this time, first, the insulating film 116 is etched, then the coil wiring 115 is etched, then the insulating film 112 is etched, then the coil wiring 111 is etched, then the insulating film 108 is etched, The coil wiring 107 is etched, then the insulating film 104 is etched, then the coil wiring 103 is etched, and finally the insulating film 102 is etched. (The substrate 101 may be etched in order to insert the core 134 below the level of the lowermost wiring 103.) This etching is performed by dry etching, and the insulating film and the conductor film are sequentially etched. Etching with a considerably high selectivity is possible, and each etching can be performed under a condition with very little etching residue. In addition, it is possible to perform etching according to a nearly vertical pattern with little side etching. In this way, the core insertion hole 119 is formed.

Next, in order to cover the wiring exposed in the insertion hole 119, an insulating film 121 (for example, SiOx, SiNy, SiOxNy, etc.) is laminated by a CVD method or a PVD method. The core insertion hole has a depth of about 2 μm to about 200 μm (or about 500 μm) and a vertical wall, but the core insertion hole has a diameter of about 50 μm to about 200 μm (or more than about 200 μm). Therefore, since the aspect ratio is not so large, it can be laminated in a state close to conformal on the side surface of the core insertion hole. The insulating film on the side wall may have a thickness of about 0.1 μm or more because a liquid insulating film is also formed thereafter. Next, the liquid insulating film 120 is formed in the core insertion hole 119 by a coating method, and the core 134 attached to the support substrate 190 is inserted as described above. The subsequent process is the same as described above. In the variation shown in FIG. 24, the core insertion hole 119 overlaps with the coil wiring, the core 134 can be brought closer, and the inductance value can be further increased. In addition, vertical core insertion holes can be formed according to the pattern. Repeated etching of the insulating film and the conductor film can be realized in a short time with the same apparatus because the gas conditions and other etching conditions may be changed as appropriate, so that there are few or almost no additional processes.

FIG. 25 shows a toroidal coil manufactured using the lateral inductor of the present invention. FIG. 25A shows a toroidal coil having a circular donut shape, and FIG. 25B shows a coil having a rectangular donut shape. As shown in FIG. 25 (a), the lower layer coil wiring 1001 (indicated by the dotted line) connected to the outside enters the upper layer coil wiring 1002, and then enters the lower layer coil wiring 1003 indicated by the dotted line. It goes around the core 1005 and goes out from the upper layer coil wiring 1004. (The coil wiring 1001 may be an upper layer. The coil wiring 1004 may be a lower layer.) If the present invention is used, such a pattern can be simplified. First, an insulating film is formed on a substrate, coil wirings 1001 and 1003 are formed thereon, then an insulating film is laminated, a disk donut-shaped core 1005 is attached, and then an insulating film is formed. A contact hole is formed and the contact hole is filled with a conductor film, and then upper coil wirings 1002 and 1004 are formed.

Also, as shown in FIG. 25 (b), the lower layer coil wiring 1006 (indicated by the dotted line) connected to the outside enters the upper layer coil wiring 1007, and then enters the lower layer coil wiring 1008 indicated by the dotted line. The core core 1010 is scattered around and goes out from the upper layer coil wiring 1009. (The coil wiring 1006 may be an upper layer. The coil wiring 1009 may be a lower layer.) If the present invention is used, such a pattern can be simplified. First, an insulating film is formed on a substrate, coil wirings 1006 and 1008 are formed thereon, then an insulating film is laminated, a rectangular plate donut-shaped core 1010 is attached, and then an insulating film is formed, A contact hole is formed and the contact hole is filled with a conductor film, and then upper coil wirings 1007 and 1009 are formed. As a result, a toroidal coil as shown in FIG. 25 can be easily produced.

FIG. 26 is a view showing the structure of a package manufactured using the vertical inductor of the present invention. A first conductor wiring 14 is formed on the insulating substrate 12, and an insulating film 15 is formed thereon. A contact hole 16 is formed in the insulating film 15, a conductor film is formed in the contact hole 16, a second conductor wiring 17 is further formed, and an insulating film 18 is formed thereon. A contact hole 19 is formed in the insulating film 18, a conductor film is formed in the contact hole 19, a third conductor wiring 20 is formed, and an insulating film 21 is formed thereon. Next, a contact hole 22 is formed in the insulating film 21, a conductor film is formed in the contact hole 22, a fourth conductor wiring 23 is formed, and an insulating film 24 is formed thereon. This process is repeated for more conductor wiring layers. Next, these conductor wirings are spirally (annular), a core insertion hole is formed inside these conductor wirings, the core 25 is inserted, and then an insulating film 26 is formed to form the core 25. Coating. Next, a contact hole 27 is formed, a conductor film is formed in the contact hole 27, and an electrode / wiring 28 is further formed. The electrode / wiring 28 serves as a connection electrode to an external element or the like. On the other hand, a contact hole 13 is formed from the back side of the insulating substrate 12 to the conductor wiring 14, a conductor film is formed in the contact hole 13, and the electrode / wiring 11 is formed on the back side of the insulating substrate 12. The electrode / wiring 11 serves as a connection electrode to an external element or the like. Alternatively, the conductor wiring 14 may be formed by forming a conductor film in the contact hole after the contact hole 13 is formed in the insulating substrate 12. The insulating substrate may be a transparent insulating substrate such as glass, quartz, or transparent plastic, or may be an insulating substrate such as a ceramic substrate or an epoxy substrate. By such a process, the inductor element package of the present invention can be formed. When a voltage is applied to the electrodes 11 and 28 on both sides and a current is passed through the conductor wiring, it can be operated as an inductor.

FIG. 27 is a diagram for explaining a method of mounting a large number of inductor (horizontal and vertical) element packages of the present invention formed on a substrate on another substrate (for example, on a mounting substrate or an IC substrate). As shown in FIG. 27A, a substrate 8001 on which many inductor element packages are formed is attached to a support substrate 8005 via an adhesive layer 8003, and the substrate 8001 is diced to separate the inductor element packages individually. At this stage, the individual inductor element packages are attached to the adhesive layer 8003 and thus do not fall apart. Next, a substrate 8007 to which a patterned adhesive layer 8009 is attached is prepared. The adhesive layer 8009 is patterned to a size that can be adhered to the inductor element package. An adhesive layer 8009 is formed in accordance with the pitch of the mounting substrate on which the inductor element is mounted. Next, as shown in FIG. 27B, the adhesive layer 8009 is adhered while aligning the pattern of the adhesive layer 8009 of the substrate 8007 with the inductor element package (8001-2 and 8002-5 in FIG. 27) to be adhered. It is attached to the power inductor element package 8001. Next, the substrate 8007 is lifted (the support substrate 8005 may be lowered), and the inductor element package 8001 (8001-2, 8001-) whose adhesive strength with the adhesive layer 8003 is weakened by applying ultraviolet rays or applying heat. 5) is separated from the adhesive layer. Next, as shown in FIG. 27C, an electrode / wiring layer 8017 formed on the mounting substrate 8013 and on which the inductor element package is to be mounted (formed on each mounting unit 8015 (8015-1 and 8015) on the mounting substrate side). In FIG. 27 (d), the inductor element package 8001 (8001-2 or 8002-5) is brought close to the pattern of FIG. ) Electrode / wiring 8011 is attached to the electrode / wiring 8017 of the mounting substrate 8013. Next, the substrate 8007 is lifted (the mounting substrate 8013 may be lowered), and the inductor element package in which the adhesive force of the adhesive layer 8009 is weakened by applying ultraviolet rays or applying heat is separated from the substrate 8007. As a result, as shown in FIG. 27E, individual inductor element packages 8001 (8001-2, 8001-5) are collectively mounted on the mounting substrate 8013. Next, as shown in FIG. 27F, the adjacent inductor element package 8001 (8001-3, 8001-6) is attached to the substrate 8007 with the adhesive layer 8009 and mounted on the mounting substrate 8013. If the mounting unit 8015 is designed to be an integral multiple of the size of the inductor element package in the mounting board 8013, a large number of inductor element packages 8001 can be automatically and collectively mounted on the mounting board. If the substrate 8007 is made of a transparent substrate such as glass, it can be matched with the inductor element package (FIGS. 27A and 27B) or matched with the electrode / wiring 8017 of the mounting substrate (FIG. 27C). , FIG. 27 (d)) facilitates alignment. Further, since the adhesive layer 8009 is vacuum-adsorbed using a mask, and the inductor element package has a magnetic layer, an electromagnet pattern or a permanent magnet pattern can be used, or a magnetic field cut layer mask can be used. The adhesive layer 8003 can also use a vacuum adsorption pattern or an electromagnet pattern. Further, in FIG. 27, the electrodes and wires are attached to each other, but it goes without saying that the package can be simply mounted.

An important point of the present invention is that a magnetic material having a high magnetic permeability attached to a support substrate is attached to a semiconductor substrate in a desired shape and used as a core of coil wiring. Even in the case of a horizontal inductor, the inductance of the coil is increased by the relative permeability as compared with the case without a core. Since the same material as the bulk material can be used as the core material in the present invention, a coil (inductor) having a very large inductance can be manufactured using a material having a relative magnetic permeability of 100 times or more, 1000 times or more and 10000 times or more. In addition, since the same process as a semiconductor process such as LSI can be used, a semiconductor device with an inductor can be manufactured at the wafer level.

In the present invention, it is obvious that the vertical inductor and the horizontal inductor are not limited to the semiconductor substrate but may be other substrates. For example, a printed wiring board can be used. Using the support substrate with a magnetic core of the present invention, the magnetic core may be inserted and attached to the printed wiring board. Further, it is obvious that it can be applied to the formation of a single inductor (coil). The present invention also has an effect that a large number of cored inductors (coils) can be formed on a substrate by a very simple method.
Note that various materials can be attached to a semiconductor substrate by applying the present invention. For example, a very accurate resistor thin plate can be attached to a semiconductor substrate, and highly accurate resistance wiring can be incorporated into a semiconductor device.
Although various descriptions have been given so far, it goes without saying that the contents described in other places can be applied as long as they are not inconsistent with each other even if they are not specifically described in the description of the embodiments and embodiments.

  The present invention can be applied to a semiconductor device using an inductor or a coil.

DESCRIPTION OF SYMBOLS 11 ... Semiconductor substrate, 12 ... Insulating film, 13 ... Coil wiring, 14 ... Insulating film,
15 ... coil wiring, 16 ... insulating film, 17 ... coil (wiring) central hole,
18 ... insulating film, 19 ... fluid adhesive, 31 ... support substrate,
32 ... Bonding agent, 33 ... Core

Claims (12)

An inductor with a core formed by inserting a core formed on a second substrate into a central hole inside a coil wiring formed on the first substrate. The cored inductor according to claim 1, wherein the first substrate is a semiconductor substrate. The cored inductor according to claim 2, wherein the terminal of the coil wiring is connected to a semiconductor device formed on the semiconductor substrate. From the second substrate on which the cored inductor formed by inserting the core formed on the third substrate is inserted into the central hole inside the coil wiring formed on the second substrate, from the first substrate A semiconductor device equipped with an inductor formed by attaching a cored inductor to a semiconductor substrate which is a substrate. A step of forming at least one layer of coil wiring on a first substrate which is a semiconductor substrate, an insulating substrate, or a conductive substrate, and a core formed on the second substrate is disposed inside the coil wiring. A method for manufacturing an inductor with a core, comprising: a step; and a step of separating a core from a second substrate. After the step of forming the coil wiring, a step of applying a fluid adhesive, a step of forming an adhesive layer on the bottom inside the coil wiring, or an adhesive layer on the core formed on the second substrate 6. The method of manufacturing a cored inductor according to claim 5, further comprising any of the steps of forming or a step of combining them. Forming a coil wiring of at least one layer on a first substrate which is a semiconductor substrate, an insulating substrate, or a conductive substrate; forming a central hole inside the coil wiring; and on the second substrate A method for manufacturing a cored inductor, comprising: inserting a formed core into the central hole; and separating the core from a second substrate. After the step of forming the central hole inside the coil wiring, the step of applying a fluid adhesive, the step of forming an adhesive layer on the bottom of the central hole, or the core formed on the second substrate The method for manufacturing a cored inductor according to claim 7, further comprising any one of the steps of forming the adhesive layer, or a combination of these steps. The cored inductor according to any one of claims 1 to 3, wherein the core is bonded to the second substrate via a bonding agent. The semiconductor device according to claim 4, wherein the core is bonded to the second substrate via a bonding agent. On the first substrate having the first wiring, the core attached to the second substrate is attached, the second wiring is formed on the second substrate, and the first wiring and the second wiring are An inductor with a core connected in a spiral with the core inside. A method of manufacturing an inductor with a core in which a coil wiring is wound spirally with a core inside, the step of forming a first coil wiring on a first substrate which is a semiconductor substrate, an insulating substrate, or a conductive substrate; The step of forming the first insulating film, the step of attaching the core attached to the second substrate to the first substrate, the step of separating the second substrate from the core, and the second insulating film are laminated. A method of manufacturing an inductor with a core, comprising: a step of forming a connection hole for connecting the first wiring and the second wiring in a spiral shape; and a step of forming a second coil wiring.

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