JP2017168654A - Manufacturing method of semiconductor device - Google Patents

Abstract

A semiconductor device manufacturing method capable of reducing the manufacturing cost of a semiconductor device manufactured by thinning a semiconductor substrate to which a supporting substrate is bonded is provided. According to one embodiment, a method for manufacturing a semiconductor device is provided. The manufacturing method of the semiconductor device concerning an embodiment includes a formation process, a pasting process, a separation process, and a use process. In the forming step, a device layer including a semiconductor device is formed on one main surface side of the semiconductor substrate. A bonding process bonds a support substrate to the device layer side in a semiconductor substrate. In the separation step, the semiconductor substrate to which the support substrate is bonded is sliced to separate the device layer from the semiconductor substrate. In the use process, the semiconductor substrate from which the device layer is separated is used next time as a support substrate. [Selection] Figure 2

Description

  Embodiments described herein relate generally to a method for manufacturing a semiconductor device.

  Conventionally, a device layer including a semiconductor device is formed on one main surface side of a semiconductor substrate, a support substrate is bonded to the device layer side of the semiconductor substrate, and then thinned by grinding from the other main surface side of the semiconductor substrate. There is a method of manufacturing a thin semiconductor device by doing so.

  In such a method for manufacturing a semiconductor device, a substrate such as a glass substrate or a wafer substrate is used as a support substrate for supporting the semiconductor substrate. Such a substrate has been discarded because it has no effective use after being peeled from the thinned semiconductor substrate.

  Therefore, such a method for manufacturing a semiconductor device has a problem that a manufacturing cost increases because a glass substrate, a wafer substrate, or the like is newly used as a support substrate every time the semiconductor substrate is thinned.

WO2013 / 128688

  An object of one embodiment is to provide a method of manufacturing a semiconductor device that can reduce the manufacturing cost of a semiconductor device manufactured by thinning a semiconductor substrate to which a support substrate is bonded.

  According to one embodiment, a method for manufacturing a semiconductor device is provided. The manufacturing method of the semiconductor device concerning an embodiment includes a formation process, a pasting process, a separation process, and a use process. In the forming step, a device layer including a semiconductor device is formed on one main surface side of the semiconductor substrate. A bonding process bonds a support substrate to the device layer side in a semiconductor substrate. In the separation step, the semiconductor substrate to which the support substrate is bonded is sliced to separate the device layer from the semiconductor substrate. In the use process, the semiconductor substrate from which the device layer is separated is used next time as a support substrate.

FIG. 1 is an explanatory diagram illustrating an example of a semiconductor substrate used in the method for manufacturing a semiconductor device according to the embodiment. FIG. 2 is a diagram illustrating a concept of a method for manufacturing a semiconductor device according to the embodiment. FIG. 3 is a cross-sectional view illustrating a manufacturing process of the semiconductor device according to the embodiment. FIG. 4 is an explanatory diagram of the semiconductor device manufacturing process according to the embodiment in a cross-sectional view. FIG. 5 is an explanatory diagram illustrating an example of a wire saw according to the embodiment. FIG. 6 is an explanatory diagram of the semiconductor device manufacturing process according to the embodiment in a cross-sectional view. FIG. 7 is a cross-sectional view illustrating a manufacturing process of the semiconductor device according to the embodiment. FIG. 8 is an explanatory diagram viewed from a cross-sectional view of the manufacturing process of the semiconductor device according to the embodiment. FIG. 9 is an explanatory diagram of the semiconductor device manufacturing process according to the embodiment in a cross-sectional view. FIG. 10 is an explanatory diagram of a semiconductor device manufacturing process according to the embodiment in a cross-sectional view. FIG. 11 is a cross-sectional view showing a semiconductor device manufactured by applying the semiconductor device manufacturing method according to the embodiment.

  Hereinafter, a method for manufacturing a semiconductor device according to an embodiment will be described in detail with reference to the accompanying drawings. In addition, this invention is not limited by this embodiment.

  FIG. 1 is an explanatory diagram illustrating an example of a semiconductor substrate used for manufacturing the semiconductor device according to the embodiment. As shown in FIG. 1, the semiconductor substrate 10 is provided with a semiconductor device 11 on one main surface side. That is, the semiconductor substrate 10 is a device layer in which the surface layer portion of one main surface includes the semiconductor device 11. The semiconductor substrate 10 has a support substrate (not shown) bonded to the surface on the device layer side. The device layer is formed using a normal device formation method.

  FIG. 2 is a diagram illustrating a concept of a method for manufacturing a semiconductor device according to the embodiment. As shown in FIG. 2, in the method of manufacturing a semiconductor device, the semiconductor substrate 10 to which the support substrate 20 is bonded via the adhesive layer 7 is sliced using a wire 30 of a wire saw. As a result, the device layer 10 b is separated from the semiconductor substrate 10. Then, the semiconductor substrate 10a from which the device layer 10b is separated is used next time as a support substrate for supporting another semiconductor substrate 10 before the device layer 10b is separated.

  That is, in this method for manufacturing a semiconductor device, it is not necessary to remove more than half of the thickness of the semiconductor substrate 10 as grinding waste in order to thin the semiconductor substrate 10, and the removed portion is effectively utilized.

  Therefore, in this method of manufacturing a semiconductor device, the semiconductor substrate 10a from which the device layer 10b is separated is used as a support substrate for supporting the other semiconductor substrate 10 before separating the device layer 10b, and thus the manufacturing cost is kept low. be able to.

  Next, with reference to FIGS. 3 to 4, the method for manufacturing the semiconductor device according to the embodiment will be specifically described. FIG. 3 is a cross-sectional view illustrating a manufacturing process of the semiconductor device according to the embodiment. Note that the semiconductor substrate 10 illustrated in FIG. 3 illustrates a part of a cross-sectional portion taken along the line A-A ′ of the semiconductor substrate 10 illustrated in FIG. 1.

  In the method for manufacturing a semiconductor device according to the embodiment, first, a semiconductor substrate 10 and a support substrate 20 are prepared. The semiconductor substrate 10 used in the embodiment is, for example, a silicon wafer having a substantially disk shape. The support substrate 20 is a wafer substrate having substantially the same shape as the semiconductor substrate 10.

  As shown in FIG. 3A, in this embodiment, the semiconductor substrate 10 and the support substrate 20 having a thickness a of, for example, 775 μm and a diameter of 300 mm (12 inches) are used. In addition, shapes, such as a material of the semiconductor substrate 10 and the support substrate 20, thickness, and a diameter, are not limited to this.

  Next, the surface 12 of the semiconductor substrate 10 whose front and back are reversed is bonded to the support substrate 20 via the adhesive layer 7. As the adhesive layer 7, for example, an organic adhesive such as urethane resin or epoxy resin is used. The adhesive layer 7 is formed by applying an adhesive to the surface of the semiconductor substrate 10 or the support substrate 20 by a spin coating method or the like.

  Subsequently, as shown in FIG. 3B, the wire 30 of the wire saw is rotated while being pressed against the peripheral surface of the semiconductor substrate 10 to which the support substrate 20 is bonded. Cut in a direction parallel to the main surface of

  Specifically, the thickness of the wire 30 having a cross-sectional diameter d of, for example, 10 to 100 μm is made to circulate while pressing from the surface 12 of the semiconductor substrate 10 to a position of a depth b of 30 to 50 μm, for example. c cuts out the semiconductor substrate 10a of 625-735 micrometers, for example.

  In this embodiment, a semiconductor substrate 10a having a thickness c having a strength for supporting another semiconductor substrate 10 before separating the device layer 10b can be cut out from the semiconductor substrate 10 by a wire saw.

  Therefore, the thickness c of the semiconductor substrate 10a is determined by the relational expression c = a− (b + d). Specifically, the thickness c of the semiconductor substrate 10a may be at least 4/5 times the thickness a of the semiconductor substrate 10 before the device layer 10a is separated.

  Here, the wire saw will be described with reference to FIG. FIG. 5 is an explanatory diagram illustrating an example of a wire saw according to the embodiment. As shown in FIG. 5, the wire saw 3 includes a wire 30, a mounting table 31, a driven pulley 32, a driving pulley 33, and a pressurizer 34.

  The wire 30 travels between these pulleys while being passed through the grooves of the four driven pulleys 32 and one drive pulley 33. As the wire 30, for example, a dichrome wire or the like is used. The driven pulley 32 rotates via the wire 30 when the drive pulley 33 is rotationally driven.

  The mounting table 31 is a table on which the support substrate 20 on which the semiconductor substrate 10 is loaded is mounted. Further, the mounting table 31 includes a driving unit such as a motor (not shown), and the driving unit moves in a direction parallel to the main surface of the semiconductor substrate 10 (an arrow indicated by f in FIG. 4).

  The mounting table 31 does not move toward the wire 30, but the mounting table 31 remains fixed and the wire 30 moves toward the mounting table 31 in parallel with the main surface of the semiconductor substrate 10. Good.

  The pressurizer 34 presses the center of the surface of the semiconductor substrate 10 mounted on the mounting table 31 and fixes the support substrate 20 to the mounting table 31 via the semiconductor substrate 10. Further, the pressurizer 34 prevents a lateral shift between the semiconductor substrate 10 and the support substrate 20 when the device layer 10 a is separated from the semiconductor substrate 10.

  In the wire saw 3, the wire 30 travels between the driven pulleys 32 in the left-right direction by the rotational drive of the drive roller 33, and the mounting table 31 moves and the peripheral surface of the semiconductor substrate 10 is pressed against the wire 30. Thus, the semiconductor substrate 10 is cut.

  Returning to FIG. 3C, next, a CMP (Chemical Mechanical Polishing) apparatus 6 polishes and smoothly finishes the back surface 13 which is a slice surface of the device layer 10 b from which the semiconductor substrate 10 a is cut out. .

  Then, the device layer 10 b is peeled from the support substrate 20. Thereafter, the device layer 10b is divided into pieces by dicing to form a plurality of semiconductor chips.

  The semiconductor substrate 10a from which the device layer 10b is separated is used next time as a support substrate for supporting another semiconductor substrate 10 before the device layer 10b is separated.

  Next, referring to FIG. 4, the semiconductor substrate 10a from which the device layer 10b is separated is used as a support substrate for supporting the other semiconductor substrate 10 before the device layer 10b is separated, and the device from the semiconductor substrate 10 is used. A process of separating the layer 10b will be described.

  FIG. 4 is an explanatory diagram of the semiconductor device manufacturing process according to the embodiment in a cross-sectional view. 4 that are the same as those shown in FIG. 3 are given the same reference numerals as those shown in FIG. 3, and descriptions thereof are omitted.

  As shown in FIG. 4A, the surface 12 of another semiconductor substrate 10 whose front and back are reversed is bonded to the semiconductor substrate 10a having a thickness c from which the device layer 10b has been separated through the adhesive layer 7.

  Here, the semiconductor substrate 10a, which is a support substrate, has a thickness c that has strength to support the semiconductor substrate 10 before the device layer 10b is separated. Therefore, even if the semiconductor substrate 10 is bonded to the semiconductor substrate 10a that is the support substrate, there is no possibility that the semiconductor substrate 10 is distorted.

  Subsequently, as shown in FIG. 4B, the wire 30 of the wire saw 3 is rotated while being pressed against the peripheral surface of the semiconductor substrate 10 to which the semiconductor substrate 10a is bonded. Cut in a direction parallel to the ten principal surfaces.

  That is, in the same manner as described above, the semiconductor substrate 10a having the thickness c having the strength to support the other semiconductor substrate 10 before separating the device layer 10b is cut out from the semiconductor substrate 10 by the wire saw 3.

  After that, as shown in FIG. 4C, the CMP apparatus 6 polishes and smoothly finishes the back surface 13 which is the slice surface of the device layer 10b from which the semiconductor substrate 10a is cut out.

  Then, the device layer 10b is peeled from the semiconductor substrate 10a which is a support substrate. Thereafter, the device layer 10b is divided into pieces by dicing to form a plurality of semiconductor chips.

  Similarly, the semiconductor substrate 10a from which the device layer 10b is separated is used next time as a support substrate for supporting another semiconductor substrate 10 before the device layer 10b is separated.

  As described above, in the method for manufacturing a semiconductor device according to the embodiment, the semiconductor substrate 10a obtained by separating the device layer 10b from the semiconductor substrate 10 is used as a support substrate for supporting the semiconductor substrate 10 for next use.

  Therefore, the manufacturing method of the semiconductor device according to the embodiment does not need to newly use a glass substrate, a wafer substrate, or the like as the support substrate every time the semiconductor substrate 10 is thinned. it can.

  Further, as described above, in the method for manufacturing a semiconductor device according to the embodiment, the device layer 10b is separated from the semiconductor substrate 10 using the wire saw 3, and therefore the back surface 13 of the semiconductor substrate 10 is ground using the grinding device. As compared with the case where the device layer 10b is left, the amount of scrap generated by the thinning process of the semiconductor substrate 10 can be greatly reduced.

  Therefore, since the manufacturing method of the semiconductor device according to the embodiment can suppress damage or contamination of the back surface 13 of the device layer 10b due to scrap, it is possible to improve the yield of the semiconductor device.

  Next, application examples of the semiconductor device manufacturing method according to the above-described embodiment will be described with reference to FIGS. Here, the manufacture of a NAND flash memory will be described as an example. 6-10 is explanatory drawing by the cross sectional view of the manufacturing process of the semiconductor device which concerns on embodiment.

  In addition, about the component similar to the component shown in FIGS. 1-3 among the components shown in FIGS. 6-10, the code | symbol same as the code | symbol shown in FIGS. 1-3 is attached | subjected, and the description is given. Is omitted.

  As shown in FIG. 6A, a multilayer wiring layer 4 in which a multilayer wiring 41 is provided in an interlayer insulating film 40, a passivation film 50, and a polyimide film 51 are laminated on the surface of the prepared semiconductor substrate 10 in this order. Formed. In the following embodiment, a process of forming a TSV (Through Silicon Via) on the semiconductor substrate 10 will be described.

  As shown in FIG. 6B, by performing etching using a resist (not shown) as a mask, the surface of the multilayer wiring 41 is projected from the surface of the polyimide film 51 to the projection position of the multilayer wiring 41 in the passivation film 50 and the polyimide film 51. An opening 5 reaching up to is formed.

  Subsequently, as shown in FIG. 6C, nickel (Ni) is buried in the opening 5 by electrolytic plating using a resist (not shown) as a mask to form a Ni electrode 52. Then, a gold (Au) film 53 is formed on the surface of the Ni electrode 52 exposed from the polyimide film 51.

  In this embodiment, a region composed of the multilayer wiring layer 4, the passivation film 50, the polyimide film 51, the Ni electrode 52, and the Au film 53 corresponds to the region of the semiconductor device 11.

  Next, as shown in FIG. 7A, an adhesive is applied to the surfaces of the polyimide film 51 and the Au film 53 to form an adhesive layer 7, and the semiconductor substrate 10 is turned upside down. The surface on the semiconductor element 11 side is bonded to the support substrate 20 via the adhesive layer 7.

  Subsequently, as shown in FIG. 7B, the semiconductor substrate 10 is rotated by rotating the wire 30 of the wire saw 3 while pressing the wire 30 against the peripheral surface of the semiconductor substrate 10 bonded to the support substrate 20. Cut in a direction parallel to the ten principal surfaces.

  Thereafter, as shown in FIG. 8A, the back surface (here, the upper surface), which is a sliced surface of the device layer 10b from which the semiconductor substrate 10a is cut out, is polished and smoothly finished by a CMP apparatus (not shown).

  The semiconductor substrate 10a from which the device layer 10b is separated is used next time as a support substrate for supporting another semiconductor substrate 10 before the device layer 10b is separated.

  Then, as shown in FIG. 8B, a protective film 60 is formed on the upper surface of the device layer 10b. Subsequently, etching is performed using a resist (not shown) as a mask to form a TSV 8 that reaches from the surface of the protective film 60 to the surface of the multilayer wiring 41 at the projection position of the multilayer wiring 41 in the device layer 10b. Thereafter, the inner peripheral surface of TSV 8 is covered with a barrier metal film 62.

  Subsequently, as shown in FIG. 8C, a resist 63 is applied to the upper surface of the device layer 10b, and the resist 63 on the TSV8 formation position is selectively removed by photolithography.

  Then, as shown in FIG. 9A, copper (Cu) is buried in the TSV 8 by electrolytic plating using the resist 63 as a mask to form the through electrode 70. Subsequently, bumps 71 are formed on the surface of the through electrode 70 with solder. Thereafter, the resist 63 formed on the upper surface of the device layer 10b is removed.

  Next, as shown in FIG. 9B, the front and back of the structure in which the device layer 10 b is bonded to the support substrate 20 are reversed, and the back surface (here, the lower surface) of the device layer 10 b is bonded to the peeling tape 80. wear.

  After that, for example, an adsorption collet (not shown) is adsorbed on the upper surface of the support substrate 20, and the support substrate 20 is picked up by the adsorption collet so that the support substrate 20 is moved along the boundary 81 shown in FIG. It peels from the device layer 10b.

  Then, as shown in FIG. 9C, the device layer 10b is divided into pieces by dicing to form a plurality of semiconductor chips 1. The plurality of semiconductor chips 1 are peeled off from the peeling tape 80 by being picked up by suction collets (not shown).

  After that, as shown in FIG. 10, the separated semiconductor chips 1a and 1b picked up by the suction collet are sequentially stacked on a wiring board (not shown). In this embodiment, the Ni chip 52 of the semiconductor chip 1a and the through electrode 70 of the semiconductor chip 1b are electrically connected by laminating the semiconductor chip 1b on the semiconductor chip 1a via the adhesive layer 82.

  Here, a semiconductor device in which a plurality of semiconductor chips are stacked on a wiring board and packaged with a mold resin will be described with reference to FIG. FIG. 11 is a cross-sectional view showing a semiconductor device manufactured by applying the semiconductor device manufacturing method according to the embodiment.

  Note that among the components shown in FIG. 11, the same components as those shown in FIG. 10 are given the same reference numerals as those shown in FIG.

  As shown in FIG. 11, the semiconductor device 9 includes a wiring substrate 90, semiconductor chips 1 a to 1 d, connection pads 91, electrode pads 92, bonding wires 93, mold resin 94, and external connection terminals 95.

  The semiconductor chips 1a to 1d are stacked in a staircase pattern so that the electrode pads 92 are respectively exposed. Specifically, the semiconductor chips 1a to 1c are stacked while being shifted in the same direction, and the semiconductor chip 1d is stacked while being shifted in the opposite direction with respect to the semiconductor chips 1a to 1c. Adhesive layers 82a to 82e are formed on both surfaces of the semiconductor chips 1a to 1d, respectively.

  The electrode pads 92 provided on each of the semiconductor chips 1 a to 1 d are electrically connected to the connection pads 91 provided on the wiring board 90 via the bonding wires 93. A mold resin 94 for sealing the semiconductor chips 1 a to 1 d is formed on the surface of the wiring substrate 90, and external connection terminals 95 are formed on the back surface of the wiring substrate 90.

  As described above, in the method for manufacturing the semiconductor device 9 according to the embodiment, the semiconductor substrate 10a in which the device layer 10b is separated from the semiconductor substrate 10 is used as a support substrate that supports the semiconductor substrate 10 for next use.

  Therefore, the manufacturing method of the semiconductor device 9 according to the embodiment does not need to newly use a glass substrate, a wafer substrate, or the like as the support substrate every time the semiconductor substrate 10 is thinned. Can do.

  Further, as described above, since the method for manufacturing the semiconductor device 9 according to the embodiment separates the device layer 10b from the semiconductor substrate 10 using the wire saw 3, the back surface of the semiconductor substrate 10 is ground using the grinding device. As compared with the case where the device layer 10b is left, the amount of scrap generated by the thinning process of the semiconductor substrate 10 can be greatly reduced.

  Therefore, since the manufacturing method of the semiconductor device 9 according to the embodiment can suppress damage or contamination of the back surface of the device layer 10b due to dust, the yield of the semiconductor device 9 can be improved.

  Further, in this form, the device layer 10b is separated from the semiconductor substrate 10 by the wire saw 3, but the form is not limited to this form. As another form, the semiconductor substrate 10 is cut | disconnected in the direction parallel to the main surface of the semiconductor substrate 10 by irradiating the peripheral surface of the semiconductor substrate 10 with which the support substrate 20 was bonded with a laser or ultrahigh pressure water. May be.

  In this form, since the device layer 10b is separated from the semiconductor substrate 10 using a laser or ultra high pressure water, the cut surface of the device layer 10b can be finished cleanly.

  In the method for manufacturing a semiconductor device according to the above-described embodiment, the surface 12 of the semiconductor substrate 10 is bonded to the semiconductor substrate 10a from which the support substrate 20 or the device layer 10b is separated via the adhesive layer 7. It is not restricted to this form. As another form, the surface 12 of the semiconductor substrate 10 may be directly bonded to the semiconductor substrate 10a from which the support substrate 20 or the device layer 10b is separated without using the adhesive layer 7.

  Even in such a form, the device layer 10 b can be separated from the semiconductor substrate 10 by the wire saw 3. Therefore, damage or contamination of the back surface of the device layer 10b due to dust can be suppressed, so that the yield of the semiconductor device can be improved.

  In the semiconductor device manufacturing method according to the above-described embodiment, the semiconductor substrate 10 and the support substrate 20 having a diameter of 12 inches (thickness 774 μm) are used, but the diameter is 6 inches (thickness 625 μm) to 8 inches (thickness). Even if the semiconductor substrate 10 and the support substrate 20 having a thickness of 725 μm are used, the same effect as described above can be obtained.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  1, 1a to 1d Semiconductor chip, 10, 10a Semiconductor substrate, 10b Device layer, 11 Semiconductor element, 12 Front surface, 13 Back surface, 20 Support substrate, 3 Wire saw, 30 Wire, 31 Mounting table, 32 Driven pulley 33 Drive pulley, 34 Pressurizer, 4 multilayer wiring layer, 40 interlayer insulating film, 41 multilayer wiring, 5 opening, 50 passivation film, 51 polyimide film, 52 Ni electrode, 53 Au film, 6 CMP apparatus, 60 protective film, 62 barrier metal film, 63 Resist, 7 Adhesive layer, 70 Through electrode, 71 Bump, 8 TSV, 80 Release tape, 81 Boundary, 82, 82a to 82e Adhesive layer, 9 Semiconductor device, 90 Wiring board, 91 Connection pad, 92 Electrode pad, 93 Bonding wire, 4 molding resin, 95 external connection terminal

Claims (5)

Forming a device layer including a semiconductor device on one main surface side of the semiconductor substrate;
Bonding a support substrate to the device layer side of the semiconductor substrate;
Slicing the semiconductor substrate to which the support substrate is bonded, and separating the device layer from the semiconductor substrate;
And a step of using the semiconductor substrate from which the device layer has been separated as the support substrate next time. The method for manufacturing a semiconductor device according to claim 1, further comprising a step of polishing and flattening a sliced surface of the device layer. The semiconductor substrate from which the device layer is separated is:
3. The method of manufacturing a semiconductor device according to claim 1, wherein a thickness is 4/5 times or more of a thickness of the semiconductor substrate before the device layer is separated. The device layer is
The semiconductor device manufacturing method according to claim 1, wherein the semiconductor device is separated from the semiconductor substrate by slicing with a wire saw. The semiconductor substrate on which the device layer is formed,
The thickness is 625 μm to 775 μm,
The wire of the wire saw is
The method for manufacturing a semiconductor device according to claim 4, wherein the cross-sectional diameter is 10 μm to 100 μm.

Images