JP2008034694A - Passive element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a passive element, and a passive element integrated circuit device in which the characteristic fluctuation of an element or a circuit after manufacturing is prevented from occurring with an inexpensive and high performance thin film passive element formed on a main inter-layer insulating film with resin as main components or a thin film passive element integrated circuit. <P>SOLUTION: In a passive element configured by alternately laminating one or more wiring and organic inter-layer insulating films on a base substrate, and including one or more passive elements in the lamination structure and a passive element integrated circuit, an inorganic cover film is formed on an organic resin inter-layer insulating film covering the uppermost layer wiring, or on the uppermost wiring layer including one or more passive elements formed on the resin in-layer insulating film. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a passive element, an interposer including the passive element, a semiconductor chip carrier, a wiring board, and a semiconductor integrated circuit device.

  In recent years, there has been a strong demand for miniaturization and high integration of circuits and components in portable devices and the like simultaneously with higher frequency and higher speed of device operation. Therefore, studies are being made on thin film passive elements using a semiconductor process, a thin film process similar to the semiconductor process, and an integration technique thereof. For example, Patent Document 1 discloses a thin film LC filter formed on a Si substrate.

  Patent Documents 2 and 3 disclose a semiconductor connection substrate in which thin-film passive elements are integrated. In either case, the interlayer insulating film has a structure using a resin such as BCB (benzocyclobutene) or polyimide. These resins are insulators excellent in high-frequency characteristics with low dielectric constant and low dielectric loss, and can be easily applied and formed, and vias can be easily formed by imparting photosensitivity.

  In Patent Document 4, a film-like interposer with a built-in capacitor is described. Resin such as polyimide is used for both the base layer for manufacturing the capacitor and the cover layer of the capacitor.

  Furthermore, Patent Documents 5 and 6 disclose passive element integration techniques on a semiconductor integrated circuit. On the semiconductor integrated circuit, there is a problem that the characteristics of the passive element and the passive element integrated circuit are deteriorated due to electrical and magnetic coupling with the substrate. In Patent Document 5, an inductor that is particularly problematic in coupling with a substrate among passive elements is arranged in the uppermost layer, and the problem is solved by using BCB for interlayer insulating films above and below the inductor. When the resin interlayer insulating film is not used, as described in Patent Document 6, a structure in which a shield layer for blocking the coupling with the substrate is specially provided between the passive element and the substrate is adopted. Become.

Japanese Patent Application Laid-Open No. 10-079469 JP 2000-124358 A WO2003 / 007369 Japanese Patent Laid-Open No. 2002-083892 JP 2002-141473 A JP 2001-267320 A

  However, these conventional thin-film passive elements and passive element integrated circuits including the example of the prior art shown in FIG. 6 have a large variation in element characteristics after the elements and substrates are formed, and the desired characteristics cannot be stably obtained. That was the problem. This is caused by the atmosphere in which the elements and the substrate are placed and the mounting process such as connection. The reason is not necessarily elucidated, but the resin interlayer insulating film covering the passive element is soft and easily affected by external stress, and moisture absorption from outside and gas release from inside can be considered.

  In the environment after the device or substrate is formed, the resin that is the interlayer insulation film absorbs moisture from the outside, or absorbs moisture or releases from the inside moisture and various gases that were not completely released during curing. Shrinkage occurs. Various deformations occur in the passive element due to the stress generated by the expansion and contraction and the external stress received in the mounting process. Due to such deformation, the electrode characteristics change if it is a capacitive element, the cross-sectional area and length of the element change if it is a resistance element, and the wiring interval changes if it is an inductor. Will change from the value of.

  The stress that causes deformation varies depending on the environment in which the element or board is placed, the process of mounting, the structure of the element or board, etc. There is also a large variation in variation.

  If an inorganic insulating film instead of resin is used for the interlayer insulating film, these problems may be solved. However, since the dielectric constant and dielectric loss are larger than resin and it is difficult to form thicker, the high frequency characteristics are inferior. In addition, there are problems that the interlayer film forming process is complicated, and that a layer for blocking bonding needs to be introduced on the semiconductor substrate as described in Patent Document 6, and the manufacturing process is further complicated.

  An object of the present invention is to provide a passive element and a passive element integrated circuit that are highly reliable and highly productive because the element characteristics are less likely to be affected by external variation after fabrication and the productivity is excellent.

  In the passive element and the passive element integrated circuit according to the first aspect of the present invention, one or more wirings and interlayer insulating films are alternately stacked on a base substrate, and one or more passive elements are included in the stacked structure. It has a structure, a resin interlayer insulating film whose main component is a resin covering the uppermost layer wiring, and an inorganic cover film disposed on the interlayer insulating film.

  The passive element integrated circuit according to the second aspect of the present invention has a structure in which one or more wirings and interlayer insulating films are alternately stacked on a base substrate, and one or more passive elements are included in the stacked structure. And an uppermost wiring layer including one or more passive elements formed on a resin interlayer insulating film containing resin as a main component, and an inorganic cover film covering the uppermost wiring layer.

  The passive element and the passive element built-in circuit according to the third embodiment of the present invention have an inorganic cover film on the upper and lower sides of the resin layer covering the passive element in a resin film including at least one thin film passive element.

  The inorganic cover film in these inventions is mainly composed of at least one of silicon oxide film, silicon nitride film, aluminum oxide, aluminum nitride, refractory metal oxide, refractory metal nitride film, and refractory metal. It is desirable to do.

  In these embodiments of the present invention, it is desirable to have an organic resin cover film on the inorganic cover film. Furthermore, as another embodiment of the present invention, it is desirable that the inorganic cover film has a structure that covers the side surface of the lower resin interlayer insulating film.

  By covering the entire circuit containing passive elements with an inorganic cover layer or base substrate that functions as a barrier against external stress, moisture absorption from the external environment, and gas release from the inside, expansion of the resin interlayer insulation film after circuit formation and It is possible to provide a highly reliable passive element or passive element integrated circuit in which the deformation of the passive element due to the contraction is suppressed, and the characteristics of the passive element and the passive element integrated circuit are not changed.

  The inorganic cover film prevents deformation of the internal resin interlayer insulation film from external stress, and at the same time acts as a barrier against moisture absorption from the environment and gas release from the interior, thereby suppressing expansion and contraction of the resin interlayer insulation film. .

  Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a sectional view of a passive element integrated circuit formed on a GaAs substrate as a first embodiment of the present invention. On a GaAs substrate 112 covered with a silicon oxide film, a MIM capacitor 110, a resistor 106, and an inductor 105, each including a lower electrode 107, a dielectric 108, and an upper electrode 109, are formed in a three-dimensional manner. An inductor 105 is formed on the uppermost wiring layer 104 and is covered with a resin insulating film 101. Further, an inorganic cover film 102 is formed on the resin insulating film 101. The inorganic cover film 102 covers the entire circuit, thereby suppressing moisture absorption of the resin insulating film 101 from the surface side and gas release to the surface side.

  Further, deformation of the lower resin insulating film 101 due to external stress in the mounting process is also suppressed. On the back side of the passive element integrated circuit, the GaAs substrate 112 and the silicon nitride film 111 formed thereon play the same role as the inorganic cover layer 102 on the front side. Therefore, after the circuit is formed, fluctuations in the characteristics of the built-in passive element can be suppressed without causing deformation of the resin insulating film 101.

  The present embodiment is characterized in that it can be easily manufactured by adding an inorganic cover film forming step to the conventional circuit manufacturing method.

  The inorganic cover film 102 in FIG. 1 includes a main component of at least one of a silicon oxide film, a silicon nitride film, aluminum oxide, aluminum nitride, a refractory metal oxide, a refractory metal nitride film, and a refractory metal. It is desirable to do. These materials have excellent barrier properties against moisture and various gases, and at the same time function as a barrier layer against external stress because they are hard and excellent in strength. Furthermore, it can be easily formed at a low temperature by a CVD method (chemical vapor deposition method) or a sputtering method, and is excellent in practicality.

  In the case where the conductive inorganic cover film 102 is applied in FIG. 1, it is necessary to insulate the external connection pad as necessary, but it can also serve as a shield layer against noise. At this time, in order to lower the electrical resistance of the shield layer, it is more effective to stack a low resistance metal such as gold or copper on the inorganic cover film 102.

  In FIG. 1, an organic cover film 103 is further formed on the inorganic cover film 102. This functions as a stress relaxation layer when connecting the passive element integrated circuit and other devices, further improving the barrier effect of external stress on the internal organic resin insulating layer 101, and at the same time, reliability of the solder connection portion. There is an advantage that the performance can be improved.

  FIG. 2 shows a sectional view of a passive element integrated circuit formed on a glass substrate 208 as a second embodiment of the present invention. An inductor 205 is formed on a glass substrate 208, and an uppermost wiring layer 204 in which a resistor 206 is formed on a resin insulating film 201 as an interlayer insulating film is formed. A capacitor 207 is also formed using the interlayer insulating film. The uppermost wiring layer 204 is covered with an inorganic cover film 202. Also in this embodiment, the inorganic cover film 202 covers the entire circuit, thereby suppressing moisture absorption of the resin insulating film 201 from the surface side and gas release to the surface side.

  In addition, deformation of the lower resin insulating film 201 due to external stress in the mounting process is also suppressed. On the back side of the passive element integrated circuit, the glass substrate performs the same function as the inorganic cover film 202. In the present embodiment, when a circuit configuration in which the inductor 205 can be disposed on a layer other than the uppermost layer using an insulating substrate is possible, the inorganic cover film 202 can be formed directly on the wiring, which simplifies the process and improves productivity. Have advantages.

  In FIG. 2, the portion of the inorganic cover film 202 that contacts the wiring must be insulative. It is desirable that at least one of a silicon oxide film, a silicon nitride film, aluminum oxide, aluminum nitride, an insulating refractory metal oxide, and an insulating refractory metal nitride film be a main component. These materials have excellent barrier properties against moisture and various gases, and at the same time function as a barrier layer against external stress because they are hard and excellent in strength. Furthermore, it can be easily formed at a low temperature by a CVD method (chemical vapor deposition method) or a sputtering method, and is excellent in practicality.

  1 and 2, the substrate is preferably a semiconductor such as silicon, GaAs, or GaN, metal, glass, or ceramic. In addition to forming active elements on the semiconductor substrate, it is also possible to form a passive element integrated circuit according to the present invention. In that case, higher integration can be expected. Metal substrates are generally more advantageous than other substrate materials in that they are inexpensive and are difficult to break and easy to handle.

  Furthermore, since the metal substrate generally has better thermal conductivity than other substrate materials, it is excellent in that the cooling efficiency can be increased when a semiconductor integrated circuit is mounted. A glass substrate is inexpensive and excellent in surface flatness and insulation, and is suitable for forming a high-frequency circuit. The ceramic substrate itself can contain passive elements, and because it is easy to form wiring that passes through the substrate and connects the substrate surface and the back surface of the substrate, higher circuit integration is achieved. And suitable for modular parts.

  FIG. 3 shows a cross-sectional view of a film capacitor as a third embodiment of the present invention. A MIM capacitor 309 composed of a lower electrode 306, a dielectric 307, and an upper electrode 308 is formed on an organic base film 302 having an inorganic cover film 303 formed on the back surface, and a resin insulating film as an interlayer insulating film thereon. 301, an inorganic cover film 303, a connection pad 305, and an organic cover film 304 are formed in this order. By adopting a structure in which the inorganic cover film 303 covers the upper and lower sides of the passive element, moisture absorption of the resin insulating film 301, gas release to the surface side, and further deformation of the lower resin insulating film 301 due to external stress in the mounting process are suppressed. To do. A film-like element is thinner than an element produced on a substrate, and is excellent as an element incorporated in a printed circuit board or the like as a whole device is thinned. By substantially covering the front and back surfaces with the inorganic cover film 303, the same effects as those of the first and second embodiments can be obtained without a base substrate.

  By arranging the inorganic cover film 303 and the base substrate on the element front and back surfaces having a large contact area with the external environment, it is possible to suppress the characteristic fluctuation after the element formation, but the element side surface is also covered with the inorganic cover. A further effect is obtained by covering with the film 303.

  FIG. 4 shows a cross-sectional view of a passive element integrated circuit formed on a glass substrate 407 before separation as an explanation of the embodiment. When a plurality of passive element integrated circuits 408 to 410 are formed on a glass substrate 407 by build-up, a resin insulating film 401 is applied to the entire surface of the substrate by a spin coat method, and a boundary portion of each circuit is also resin by via formation lithography. The insulating film 401 is removed. If the inorganic cover film 402 is formed, not only the circuit surface but also the side surface can be covered with the inorganic cover film 402.

  In FIG. 4, the inorganic cover film 402 and the upper organic cover film 403 are also separated for each circuit in a shape larger than the already formed inner resin insulating film 401. With this structure, the dicing blade cuts only the glass substrate when dicing into individual pieces by dicing lines 411 and 412, and the inorganic cover film 402 is cracked or peeled off. There is an advantage that can be prevented. The effect of covering the element side surface with the inorganic cover film 402 is the same in the second and third embodiments.

  FIG. 5 shows a sectional view of a passive element integrated circuit formed on a silicon substrate as a fifth embodiment of the present invention. In the present embodiment, the lowermost passive element is covered with an interlayer insulating film of a silicon thermal oxide film 502 and a silicon oxide film 501. As described above, when a part of the interlayer insulating film is an inorganic insulating film, the passive element covered with the inorganic insulating film has an advantage that the characteristic variation during the manufacturing process can be suppressed. In particular, the effect is great when the resistor or the dielectric is a material that is easily affected by moisture generated when the resin insulating film is cured. Also in this case, if the inductor 105 is covered with the resin insulating film 101 having a low dielectric constant and low loss, the characteristics of the inductor 105 are not impaired. It is possible to suppress fluctuations in wiring characteristics.

  In addition to being used as a passive element alone, the present invention is used for functional circuit elements such as decoupling and filters, and semiconductor chip carriers, module substrates, interposers, and semiconductor integrated circuit devices that contain them.

Sectional drawing which shows the 1st Embodiment of this invention. Sectional drawing which shows the 2nd Embodiment of this invention. Sectional drawing which shows the 3rd Embodiment of this invention. Sectional drawing which shows the 4th Embodiment of this invention. Sectional drawing which shows the 5th Embodiment of this invention. Sectional drawing which shows the form of the conventional passive element built-in circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Organic resin insulating film 102 Inorganic cover film 103 Organic cover film 104 Wiring 105 Inductor 106 Resistance 107 Lower electrode 108 Dielectric 109 Upper electrode 110 MIM capacitor 111 Silicon nitride film 112 GaAs substrate 113 Semiconductor integrated circuit device 201 Organic resin insulating film 202 Inorganic Cover film 203 Organic cover film 204 Wiring 205 Inductor 206 Resistance 207 Capacitor 208 Glass substrate 209 Semiconductor integrated circuit device 301 Organic resin insulating film 302 Organic base film 303 Inorganic cover film 304 Organic cover film 305 Connection pad 306 Lower electrode 307 Dielectric 308 Upper part Electrode 309 MIM capacitor 401 Organic resin insulating film 402 Inorganic cover film 403 Organic cover film 404 Wiring 405 Inductor 406 Capacitor 407 Glass substrate 408 to 410 In passive element Warehouse circuits 411, 412 Dicing line 501 Silicon oxide film 502 Silicon thermal oxide film

Claims (10)

On the base substrate, one or more layers of wiring and interlayer insulating films are alternately stacked, and the structure in which one or more passive elements are included in the stacked structure and the resin interlayer insulation mainly composed of resin covering the uppermost layer wiring A passive element having a film and an inorganic cover film disposed on the interlayer insulating film. The inorganic cover film is mainly composed of at least one of silicon oxide film, silicon nitride film, aluminum oxide, aluminum nitride, refractory metal oxide, refractory metal nitride film, and refractory metal. The passive element according to claim 1, wherein: On the base substrate, one or more layers of wiring and interlayer insulating film are alternately stacked, and the stacked structure includes one or more passive elements and a resin interlayer insulating film containing resin as the main component. A passive element comprising: an uppermost wiring layer including at least one passive element; and an inorganic cover film covering the uppermost wiring layer. The inorganic cover film includes at least one of a silicon oxide film, a silicon nitride film, aluminum oxide, aluminum nitride, an insulating refractory metal oxide, and an insulating refractory metal nitride as a main component. 4. The passive element according to claim 3, wherein The passive element according to claim 1, wherein the inorganic cover film covers a side surface of a lower resin interlayer insulating film. 6. The passive element according to claim 1, further comprising a resin cover film on the inorganic cover film. The passive element according to claim 1, wherein the base substrate is any one of a semiconductor, a metal, glass, and ceramics. A passive element comprising a resin film including at least one thin-film passive element, wherein an inorganic cover film is provided on the upper and lower outer sides of the resin layer covering the passive element. The inorganic cover film is mainly composed of at least one of silicon oxide film, silicon nitride film, aluminum oxide, aluminum nitride, refractory metal oxide, refractory metal nitride film, and refractory metal. 9. The passive element according to claim 8, wherein 10. The passive element according to claim 8, further comprising an organic resin cover film on a side of the inorganic cover film on which the connection terminal is disposed.

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