Method for manufacturing a photodetection device

Abstract

To provide a method of manufacturing a light detection device capable of connecting between a light receiving element and a circuit structure with certainty.SOLUTION: A method of manufacturing a light detection device includes: a preparing step of preparing a semiconductor wafer with a first principal surface and a second principal surface; a supporting step of providing a first support substrate on the first principal surface after the preparing step; a cutting step of cutting the semiconductor wafer and the first support substrate in a state where the first support substrate is provided on the first principal surface after the supporting step, and obtaining a light receiving element in a state where a support member is provided on a first surface; a connecting step of electrically and physically connecting between the light receiving element and a circuit structure in a state where the support member is provided on the first surface by using a plurality of connection members arranged between a second surface and a mounting surface of the circuit structure after the cutting step; a removing step of removing the support member from the first surface after the connecting step; and an arranging step of arranging an underfill on the second principal surface or the second surface after the preparing step and before the connecting step.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a method for manufacturing an optical detection device.

Background Art

[0002] Non-Patent Document 1 describes a method for manufacturing a CMOS image sensor, which includes a step of attaching a support tape to a photodiode array wafer, a step of dicing the photodiode array wafer together with the support tape and peeling the support tape from the photodiode array chip, and a step of mounting the photodiode array chip in a state where the support tape has been peeled off on a CMOS readout circuit chip.

Prior Art Document

Non-Patent Document

[0003]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method for manufacturing a CMOS image sensor described in Non-Patent Document 1, as the light-receiving elements such as a photodiode array chip are thinned, it becomes more difficult to handle the light-receiving elements. As a result, there is a risk of problems occurring in the connection between the light-receiving elements and a circuit structure such as a CMOS readout circuit chip. Further, as the light-receiving elements such as a photodiode array chip are thinned, in a light detection device such as a manufactured CMOS image sensor, the light-receiving elements are more likely to be deformed by the influence of stress, static electricity, etc. As a result, there is a risk that the light-receiving elements come into contact with the circuit structure and the light-receiving elements are damaged.

[0005] An object of the present invention is to provide a method for manufacturing a light detection device capable of surely implementing the connection between a light-receiving element and a circuit structure even when the light-receiving element is thinned.

Means for Solving the Problems

[0006] The method for manufacturing a light detection device of the present invention includes a first step of preparing a semiconductor wafer having a first main surface and a second main surface opposite to the first main surface, and in which a plurality of two-dimensionally arranged light-receiving regions are formed; a second step of providing a first support substrate on the first main surface after the first step; a third step of obtaining a light-receiving element corresponding to a part of the cut semiconductor wafer in a state where a support member corresponding to a part of the cut first support substrate is provided on a first surface corresponding to a part of the cut first main surface, by cutting the semiconductor wafer and the first support substrate for each of the plurality of light-receiving regions with the first support substrate provided on the first main surface after the second step; a fourth step of electrically and physically connecting the light-receiving element and the circuit structure in a state where the support member is provided on the first surface, using a plurality of connection members arranged between a second surface corresponding to a part of the cut second main surface and a mounting surface of the circuit structure after the third step; and a fifth step of removing the support member from the first surface after the fourth step.

[0007] In the method for manufacturing this photodetection device, with a first support substrate provided on the first main surface of a semiconductor wafer, the semiconductor wafer and the first support substrate are cut for each of the plurality of light-receiving regions. With a support member provided on the first surface of the light-receiving element, the light-receiving element and the circuit structure are electrically and physically connected, and then the support member is removed from the first surface of the light-receiving element. In this way, when connecting the light-receiving element and the circuit structure, a support member is provided on the first surface of the light-receiving element. Therefore, even if the light-receiving element is thinned, it is possible to prevent the handling of the light-receiving element from becoming difficult. Thus, according to the method for manufacturing this photodetection device, even if the light-receiving element is thinned, the connection between the light-receiving element and the circuit structure can be reliably carried out.

[0008] In the method for manufacturing the photodetection device of the present invention, the plurality of light-receiving regions may be two-dimensionally arranged on the second main surface side with respect to the semiconductor substrate included in the semiconductor wafer. Thereby, in the light-receiving element, since the light-receiving regions are arranged on the circuit structure side with respect to the semiconductor substrate, it is possible to obtain a photodetection device including a back-illuminated type light-receiving element.

[0009] The method for manufacturing the photodetection device of the present invention further includes a sixth step of providing a second support substrate on the second main surface after the first step and before the second step, and a seventh step of thinning the semiconductor wafer in a state where the second support substrate is provided on the second main surface after the sixth step and before the second step. In the second step, the first support substrate may be provided on the first main surface in a state where the second support substrate is provided on the second main surface, and the second support substrate may be removed from the second main surface in a state where the first support substrate is provided on the first main surface. Thereby, the semiconductor wafer can be thinned in a stable state.

[0010] The method for manufacturing the photodetection device of the present invention may further include an eighth step of providing a plurality of bump electrodes as a plurality of connection members on the second main surface after the second step and before the third step. Thereby, a plurality of bump electrodes can be efficiently provided for each of the plurality of light-receiving regions.

[0011] In the method for manufacturing the photodetection device of the present invention, the plurality of light-receiving regions may be two-dimensionally arranged on the first main surface side with respect to the semiconductor substrate included in the semiconductor wafer. As a result, in the light-receiving element, since the light-receiving regions are arranged on the side opposite to the circuit structure with respect to the semiconductor substrate, a photodetection device including a surface-incident type light-receiving element can be obtained.

[0012] The method for manufacturing the photodetection device of the present invention may further include a sixth step of thinning the semiconductor wafer in a state where a first support substrate is provided on the first main surface after the second step and before the third step. Thereby, the semiconductor wafer can be thinned in a stable state.

[0013] The method for manufacturing the photodetection device of the present invention may further include a seventh step of providing a plurality of bump electrodes as a plurality of connection members on the second main surface after the sixth step and before the third step. Thereby, a plurality of bump electrodes can be efficiently provided for each of the plurality of light-receiving regions.

[0014] The photodetection device of the present invention has a first surface and a second surface opposite to the first surface, a light-receiving element provided with a light-receiving region, a circuit structure having a mounting surface, and is disposed between the second surface and the mounting surface, and includes a plurality of connection members that electrically and physically connect the light-receiving element and the circuit structure, and the height of each of the plurality of connection members is larger than the width of the light-receiving element in the direction perpendicular to the first surface.

[0015] In this photodetection device, the height of each of the plurality of connection members that electrically and physically connect the light-receiving element and the circuit structure is larger than the width of the light-receiving element in the direction perpendicular to the first surface. As a result, even if the light-receiving element is thinned and is likely to be deformed due to the influence of stress, static electricity, etc., the light-receiving element is prevented from contacting the circuit structure. Therefore, according to this photodetection device, even if the light-receiving element is thinned, it is possible to prevent the light-receiving element from being damaged due to deformation.

[0016] In the light detection device of the present invention, the height of each of the plurality of connection members may be at least twice the width of the light receiving element in the direction perpendicular to the first surface. Thereby, even if the light receiving element is thinned, it is possible to more reliably prevent the light receiving element from contacting the circuit structure.

[0017] In the light detection device of the present invention, the height of each of the plurality of connection members may be at least five times the width of the light receiving element in the direction perpendicular to the first surface. Thereby, even if the light receiving element is thinned, it is possible to more reliably prevent the light receiving element from contacting the circuit structure.

[0018] In the light detection device of the present invention, the plurality of connection members may be a plurality of bump electrodes. Thereby, while preventing the light receiving element from contacting the circuit structure, it is possible to surely connect the light receiving element and the circuit structure.

[0019] The light detection device of the present invention may further include an underfill disposed between the second surface and the mounting surface. Thereby, while protecting the plurality of bump electrodes, it is possible to reinforce the connection between the light receiving element and the circuit structure.

[0020] In the light detection device of the present invention, the width of the light receiving element in the direction parallel to the first surface may be at least ten times the width of the light receiving element in the direction perpendicular to the first surface. Thus, even when the light receiving element is thinned and has a large area, it is possible to prevent the light receiving element from being damaged due to deformation.

Advantages of the Invention

[0021] According to the present invention, it becomes possible to provide a method for manufacturing a light detection device capable of surely connecting a light receiving element and a circuit structure even if the light receiving element is thinned.

Brief Description of the Drawings

[0022]

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Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are denoted by the same reference numerals, and redundant descriptions are omitted. [First Embodiment] [Configuration of Photodetection Device]

[0024] As shown in FIGS. 1 and 2, the photodetection device 10 includes a light receiving element 11 and a circuit board (circuit structure) 12. The light receiving element 11 is mounted on the circuit board 12. The light receiving element 11 is a back-illuminated semiconductor light receiving element. The photodetection device 10 constitutes, for example, a CCD (Charge-Coupled Device) area sensor. In the following description, the incident direction of light with respect to the light receiving element 11 is referred to as the Z-axis direction, a direction perpendicular to the Z-axis direction is referred to as the X-axis direction, and a direction perpendicular to the Z-axis direction and the X-axis direction is referred to as the Y-axis direction.

[0025] The light receiving element 11 has a back surface (first surface) 11a and a front surface (second surface) 11b. The front surface 11b is a surface opposite to the back surface 11a. The light receiving element 11 is a back-illuminated semiconductor light receiving element having the back surface 11a as a light incident surface. A light shielding member 117 that defines a light incident region is provided on the back surface 11a. The light shielding member 117 is formed, for example, in a rectangular frame shape by metal and extends along the outer edge portion of the back surface 11a.

[0026] The light-receiving element 11 is formed, for example, in a rectangular plate shape. The width of the light-receiving element 11 in the direction parallel to the back surface 11a is 10 times or more the width of the light-receiving element 11 in the Z-axis direction perpendicular to the back surface 11a (i.e., the thickness of the light-receiving element 11). Note that the width of the light-receiving element 11 in the direction parallel to the back surface 11a means the minimum width among the widths of the light-receiving element 11 in all directions parallel to the back surface 11a. As an example, the width of the light-receiving element 11 in the X-axis direction is about 50 mm, the width of the light-receiving element 11 in the Y-axis direction is about 20 mm, and the thickness of the light-receiving element 11 is about 15 μm. In this case, the width of the light-receiving element 11 in the direction parallel to the back surface 11a is about 20 mm (the width of the light-receiving element 11 in the Y-axis direction).

[0027] The circuit board 12 has a mounting surface 12a facing the front surface 11b of the light-receiving element 11. The circuit board 12 is formed, for example, in a rectangular plate shape. As an example, the width of the circuit board 12 in the X-axis direction is about 80 mm, the width of the circuit board 12 in the Y-axis direction is about 100 mm, and the width of the circuit board 12 in the Z-axis direction (i.e., the thickness of the circuit board 12) is about 3 mm.

[0028] A plurality of bump electrodes (a plurality of connection members) 13 are arranged between the front surface 11b of the light-receiving element 11 and the mounting surface 12a of the circuit board 12. The plurality of bump electrodes 13 electrically and physically connect the light-receiving element 11 and the circuit board 12. The height of each bump electrode 13 (i.e., the distance between the front surface 11b of the light-receiving element 11 and the mounting surface 12a of the circuit board 12) is greater than the thickness of the light-receiving element 11. As an example, the height of each bump electrode 13 is about 40 μm. An underfill 14 is arranged between the front surface 11b of the light-receiving element 11 and the mounting surface 12a of the circuit board 12. The underfill 14 surrounds each bump electrode 13 between the front surface 11b of the light-receiving element 11 and the mounting surface 12a of the circuit board 12.

[0029] As shown in FIG. 3, the light-receiving element 11 includes an n + -type semiconductor substrate 111, an n - -type semiconductor layer 112, and a p -type semiconductor layer 113 and a plurality of p + type semiconductor regions 114. The semiconductor layer 112 is formed on the semiconductor substrate 111, for example, by epitaxial growth. The semiconductor layer 113 is formed on the semiconductor layer 112, for example, by epitaxial growth. The plurality of semiconductor regions 114 are formed in the semiconductor layer 113, for example, by impurity diffusion. The plurality of semiconductor regions 114 are arranged two-dimensionally (for example, in a matrix with the X-axis direction as the row direction and the Y-axis direction as the column direction) when viewed from the Z-axis direction. In the light receiving element 11, the semiconductor substrate 111 is located on the back surface 11a side, and the semiconductor layer 113 and the plurality of semiconductor regions 114 are located on the front surface 11b side. An AR (Anti Reflection) film 118 is formed on the surface of the semiconductor substrate 111 on the back surface 11a side.

[0030] In the light receiving element 11, the semiconductor layer 112 and the semiconductor layer 113 form a pn junction and constitute a light receiving region 11R that functions as a photoelectric conversion region. The light receiving region 11R is located on the front surface 11b side with respect to the semiconductor substrate 111. The portion corresponding to each semiconductor region 114 in the light receiving region 11R constitutes a pixel. An electrode pad 116 is provided on the front surface 11b for each semiconductor region 114. Each electrode pad 116 is electrically connected to the corresponding semiconductor region 114. The bump electrode 13 electrically and physically connects the electrode pads 116 of the light receiving elements 11 facing each other in the Z-axis direction and the electrode pads (not shown) of the circuit board 12. Note that the p-type and n-type conductivity types in the light receiving element 11 may be opposite to those described above. [Method of manufacturing a light detection device]

[0031] First, as shown in FIG. 4, a semiconductor wafer 110 is prepared (first step). The semiconductor wafer 110 has a first main surface 110a and a second main surface 110b. The second main surface 110b is the surface on the side opposite to the first main surface 110a. A plurality of light-receiving regions 11R are formed in the semiconductor wafer 110. The plurality of light-receiving regions 11R are two-dimensionally arranged on the second main surface 110b side with respect to the semiconductor substrate 110s included in the semiconductor wafer 110. That is, the semiconductor wafer 110 includes a plurality of light-receiving elements 11 respectively corresponding to the plurality of light-receiving regions 11R. Note that FIG. 4 shows a portion of the semiconductor wafer 110 corresponding to one light-receiving region 11R.

[0032] Subsequently, as shown in FIG. 5, a support substrate (second support substrate) 300 is provided on the second main surface 110b of the semiconductor wafer 110 (sixth step). The support substrate 300 is, for example, a glass substrate. The support substrate 300 is fixed to the second main surface 110b of the semiconductor wafer 110 by, for example, an adhesive.

[0033] Subsequently, as shown in FIG. 6, with the support substrate 300 provided on the second main surface 110b, the semiconductor wafer 110 is thinned (seventh step). The semiconductor wafer 110 is thinned, for example, by polishing the first main surface 110a. Subsequently, a film that becomes the AR film 118 is formed on the first main surface 110a, and a member that becomes the light-shielding member 117 is formed on the film (not shown).

[0034] Subsequently, as shown in FIGS. 7 and 8, with the support substrate 300 provided on the second main surface 110b, a support substrate (first support substrate) 400 is provided on the first main surface 110a. With the support substrate 400 provided on the first main surface 110a, the support substrate 300 is removed from the second main surface 110b. In this way, the support substrate 400 is provided on the first main surface 110a of the semiconductor wafer 110 (second step). The support substrate 400 is, for example, a glass substrate. The support substrate 400 is fixed to the first main surface 110a of the semiconductor wafer 110 by, for example, an adhesive. The support substrate 300 is peeled off from the second main surface 110b by reducing the adhesive strength of the adhesive disposed between the semiconductor wafer 110 and the support substrate 300 by, for example, light irradiation, heating, dissolution by a chemical solution, decomposition by a dry process (gas), etc. The adhesive remaining on the second main surface 110b of the semiconductor wafer 110 is removed from the second main surface 110b by, for example, dissolution by a chemical solution, decomposition by a dry process, peeling by a tape, etc.

[0035] Subsequently, as shown in FIG. 9, a plurality of bump electrodes 13 are provided on the second main surface 110b of the semiconductor wafer 110 (eighth step). In each light-receiving region 11R, each bump electrode 13 is formed on each electrode pad 116 (see FIG. 3).

[0036] Subsequently, as shown in FIG. 10, an underfill 14 is disposed on the second main surface 110b so as to cover the plurality of bump electrodes 13. The underfill 14 is, for example, a film-shaped resin film.

[0037] Subsequently, as shown in FIG. 11, with the support substrate 400 provided on the first main surface 110a, the semiconductor wafer 110 and the support substrate 400 are cut for each light-receiving region 11R, and a light-receiving element 11 corresponding to a part of the cut semiconductor wafer 110 is obtained in a state where a support member 400a corresponding to a part of the cut support substrate 400 is provided on the back surface 11a corresponding to a part of the cut first main surface 110a (third step). Thereby, a plurality of light-receiving elements 11 are obtained from the semiconductor wafer 110.

[0038] Subsequently, as shown in FIG. 12, using a plurality of bump electrodes 13 and 15 disposed between a surface 11b corresponding to a part of the cut second main surface 110b and a mounting surface 12a of the circuit board 12, the light receiving element 11 and the circuit board 12 are electrically and physically connected in a state where a support member 400a is provided on the back surface 11a (fourth step). Note that the plurality of bump electrodes 15 are provided on the mounting surface 12a of the circuit board 12. The light receiving element 11 and the circuit board 12 are electrically and physically connected by bonding a pair of bump electrodes 13 and 15 facing each other in the Z-axis direction by pressure and heating.

[0039] Subsequently, as shown in FIG. 13, the support member 400a is removed from the back surface 11a (fifth step). The support member 400a is peeled off from the back surface 11a by reducing the adhesive strength of the adhesive disposed between the light receiving element 11 and the support member 400a, for example, by light irradiation, heating, dissolution by a chemical solution, or the like. Note that the adhesive remaining on the back surface 11a of the light receiving element 11 is removed from the back surface 11a, for example, by dissolution by a chemical solution, decomposition by a dry process, peeling by a tape, or the like. Thus, the photodetection device 10 is obtained. [Operation and Effect]

[0040] In the method for manufacturing the photodetection device 10, with the support substrate 400 provided on the first main surface 110a of the semiconductor wafer 110, the semiconductor wafer 110 and the support substrate 400 are cut for each of the plurality of light receiving regions 11R, and in a state where the support member 400a is provided on the back surface 11a of the light receiving element 11, the light receiving element 11 and the circuit board 12 are electrically and physically connected, and then the support member 400a is removed from the back surface 11a of the light receiving element 11. In this way, when connecting the light receiving element 11 and the circuit board 12, the support member 400a is provided on the back surface 11a of the light receiving element 11. Therefore, even if the light receiving element 11 is thinned, it is possible to prevent the handling of the light receiving element 11 from becoming difficult. Thus, according to the method for manufacturing the photodetection device 10, even if the light receiving element 11 is thinned, the connection between the light receiving element 11 and the circuit board 12 can be surely performed.

[0041] In the manufacturing method of the photodetection device 10, a plurality of light-receiving regions 11R are two-dimensionally arranged on the second main surface 110b side with respect to the semiconductor substrate 110s included in the semiconductor wafer 110. As a result, in the light-receiving element 11, the light-receiving regions 11R are arranged on the circuit board 12 side with respect to the semiconductor substrate 110s, so that a photodetection device 10 including a back-illuminated light-receiving element 11 can be obtained.

[0042] In the manufacturing method of the photodetection device 10, before providing the support substrate 400 on the first main surface 110a of the semiconductor wafer 110, the support substrate 300 is provided on the second main surface 110b of the semiconductor wafer 110, and the semiconductor wafer 110 is thinned in a state where the support substrate 300 is provided on the second main surface 110b. When providing the support substrate 400 on the first main surface 110a of the semiconductor wafer 110, the support substrate 400 is provided on the first main surface 110a of the semiconductor wafer 110 in a state where the support substrate 300 is provided on the second main surface 110b, and the support substrate 300 is removed from the second main surface 110b of the semiconductor wafer 110 in a state where the support substrate 400 is provided on the first main surface 110a. Thereby, the semiconductor wafer 110 can be thinned in a stable state.

[0043] In the manufacturing method of the photodetection device 10, a plurality of bump electrodes 13 are provided on the second main surface 110b of the semiconductor wafer 110 in a state where the support substrate 400 is provided on the first main surface 110a. Thereby, a plurality of bump electrodes 13 can be efficiently provided for each of the plurality of light-receiving regions 11R.

[0044] In the photodetection device 10, the height of each of the plurality of bump electrodes 13 that electrically and physically connect the light-receiving element 11 and the circuit board 12 is larger than the width of the light-receiving element 11 in the direction perpendicular to the back surface 11a. As a result, even if the light-receiving element 11 is thinned and the light-receiving element 11 is likely to be deformed due to the influence of stress, static electricity, etc., the light-receiving element 11 is prevented from contacting the circuit board 12. Therefore, according to the photodetection device 10, even if the light-receiving element 11 is thinned, it is possible to prevent the light-receiving element 11 from being damaged due to deformation.

[0045] In the light detection device 10, the light receiving element 11 and the circuit board 12 are electrically and physically connected by a plurality of bump electrodes 13. Thereby, while preventing the light receiving element 11 from contacting the circuit board 12, the connection between the light receiving element 11 and the circuit board 12 can be surely implemented.

[0046] In the light detection device 10, an underfill 14 is disposed between the surface 11b of the light receiving element 11 and the mounting surface 12a of the circuit board 12. Thereby, while protecting the plurality of bump electrodes 13, the connection between the light receiving element 11 and the circuit board 12 can be reinforced.

[0047] In the light detection device 10, the width of the light receiving element 11 in the direction parallel to the back surface 11a is 10 times or more the width of the light receiving element 11 in the direction perpendicular to the back surface 11a. In this way, even when the light receiving element 11 is thinned and enlarged in area, it is possible to prevent the light receiving element 11 from being damaged due to deformation. [Second Embodiment] [Configuration of Light Detection Device]

[0048] As shown in FIGS. 14 and 15, the light detection device 20 includes a light receiving element 21 and a circuit element (circuit structure) 22. The light receiving element 21 is mounted on the circuit element 22. The light receiving element 21 is a surface-incident type semiconductor light receiving element. The circuit element 22 is, for example, an integrated circuit element such as an ASIC (Application Specific Integrated Circuit). The light detection device 20 constitutes, for example, a silicon photodiode array. In the following description, the incident direction of light with respect to the light receiving element 21 is referred to as the Z-axis direction, a direction perpendicular to the Z-axis direction is referred to as the X-axis direction, and a direction perpendicular to the Z-axis direction and the X-axis direction is referred to as the Y-axis direction.

[0049] The light receiving element 21 has a surface (first surface) 21a and a back surface (second surface) 21b. The back surface 21b is a surface on the opposite side of the surface 21a. The light receiving element 21 is a surface-incident type semiconductor light receiving element having the surface 21a as a light incident surface.

[0050] The light-receiving element 21 is formed, for example, in a rectangular plate shape. The width of the light-receiving element 21 in the direction parallel to the surface 21a is 10 times or more the width of the light-receiving element 21 in the Z-axis direction perpendicular to the surface 21a (i.e., the thickness of the light-receiving element 21). Note that the width of the light-receiving element 21 in the direction parallel to the surface 21a means the minimum width among the widths of the light-receiving element 21 in all directions parallel to the surface 21a. As an example, the width of the light-receiving element 21 in the X-axis direction and the width of the light-receiving element 21 in the Y-axis direction are each about 5 mm, and the thickness of the light-receiving element 21 is about 15 μm. In this case, the width of the light-receiving element 21 in the direction parallel to the surface 21a is about 5 mm (each of the width of the light-receiving element 21 in the X-axis direction and the width of the light-receiving element 21 in the Y-axis direction).

[0051] The circuit element 22 has a mounting surface 22a facing the back surface 21b of the light-receiving element 21. The circuit element 22 is formed, for example, in a rectangular plate shape. As an example, the width of the circuit element 22 in the X-axis direction and the width of the circuit element 22 in the Y-axis direction are each about 6 mm, and the width of the circuit element 22 in the Z-axis direction (i.e., the thickness of the circuit element 22) is about 0.7 mm.

[0052] A plurality of bump electrodes 13 are arranged between the back surface 21b of the light-receiving element 21 and the mounting surface 22a of the circuit element 22. The plurality of bump electrodes 13 electrically and physically connect the light-receiving element 21 and the circuit element 22. The height of each bump electrode 13 (i.e., the distance between the back surface 21b of the light-receiving element 21 and the mounting surface 22a of the circuit element 22) is larger than the thickness of the light-receiving element 21. As an example, the height of each bump electrode 13 is about 40 μm. An underfill 14 is arranged between the back surface 21b of the light-receiving element 21 and the mounting surface 22a of the circuit element 22. The underfill 14 surrounds each bump electrode 13 between the back surface 21b of the light-receiving element 21 and the mounting surface 22a of the circuit element 22.

[0053] As shown in FIG. 16, the light-receiving element 21 is an n + -type semiconductor substrate 211, an n - -type semiconductor layer 212, and a p -a semiconductor layer 213 of a certain type, and a plurality of p + type semiconductor regions 214. The semiconductor layer 212 is formed on the semiconductor substrate 211, for example, by epitaxial growth. The semiconductor layer 213 is formed on the semiconductor layer 212, for example, by epitaxial growth. The plurality of semiconductor regions 214 are formed in the semiconductor layer 213, for example, by impurity diffusion. The plurality of semiconductor regions 214 are arranged two-dimensionally (for example, in a matrix with the X-axis direction as the row direction and the Y-axis direction as the column direction) when viewed from the Z-axis direction. In the light receiving element 21, the semiconductor substrate 211 is located on the back surface 21b side, and the semiconductor layer 213 and the plurality of semiconductor regions 214 are located on the front surface 21a side.

[0054] In the light receiving element 21, the semiconductor layer 212 and the semiconductor layer 213 form a pn junction and constitute a light receiving region 21R that functions as a photoelectric conversion region. The light receiving region 21R is located on the front surface 21a side with respect to the semiconductor substrate 211. The portion corresponding to each semiconductor region 214 in the light receiving region 21R constitutes a pixel. Insulating regions 215 are provided in the semiconductor substrate 211 and the semiconductor layers 212 and 213 to electrically define the pixel. Electrode pads 216 are provided on the back surface 21b for each semiconductor region 214. Each electrode pad 216 is electrically connected to the corresponding semiconductor region 214 through a wiring 219 partially formed in a through hole 218. The wiring 219 is covered by insulating films 217a and 217b except for the electrical connection portions. The bump electrode 13 electrically and physically connects the electrode pads 216 of the light receiving elements 21 facing each other in the Z-axis direction and the electrode pads (not shown) of the circuit element 22. Note that the p-type and n-type conductivity types in the light receiving element 21 may be opposite to those described above. [Method for manufacturing a photodetection device]

[0055] First, as shown in FIG. 17, a semiconductor wafer 210 is prepared (first step). The semiconductor wafer 210 has a first main surface 210a and a second main surface 210b. The second main surface 210b is the surface on the side opposite to the first main surface 210a. A plurality of light-receiving regions 21R are formed in the semiconductor wafer 210. The plurality of light-receiving regions 21R are two-dimensionally arranged on the first main surface 210a side with respect to the semiconductor substrate 210s included in the semiconductor wafer 210. That is, the semiconductor wafer 210 includes a plurality of light-receiving elements 21 respectively corresponding to the plurality of light-receiving regions 21R.

[0056] Subsequently, as shown in FIG. 18, a support substrate 400 is provided on the first main surface 210a of the semiconductor wafer 210 (second step). The support substrate 400 is, for example, a glass substrate. The support substrate 400 is fixed to the first main surface 210a of the semiconductor wafer 210 by, for example, an adhesive.

[0057] Subsequently, as shown in FIG. 19, with the support substrate 400 provided on the first main surface 210a, the semiconductor wafer 210 is thinned (sixth step). The semiconductor wafer 210 is thinned, for example, by polishing the second main surface 210b. Subsequently, through holes 218, electrode pads 216, wirings 219, etc. are formed (not shown).

[0058] Subsequently, as shown in FIG. 20, a plurality of bump electrodes 13 are provided on the second main surface 210b of the semiconductor wafer 210 (seventh step). In each light-receiving region 21R, each bump electrode 13 is formed on each electrode pad 216 (see FIG. 3).

[0059] Subsequently, as shown in FIG. 21, with the support substrate 400 provided on the first main surface 210a, the semiconductor wafer 210 and the support substrate 400 are cut for each light-receiving region 21R, and a support member 400a corresponding to a part of the cut support substrate 400 is provided on a surface 21a corresponding to a part of the cut first main surface 210a, and a light-receiving element 21 corresponding to a part of the cut semiconductor wafer 210 is obtained (third step). Thereby, a plurality of light-receiving elements 21 are obtained from the semiconductor wafer 210.

[0060] Subsequently, as shown in FIG. 22, an underfill 14 is disposed on the back surface 21b so as to cover the plurality of bump electrodes 13. The underfill 14 is, for example, a film-shaped resin film.

[0061] Subsequently, as shown in FIG. 23, using the plurality of bump electrodes 13 and 15 disposed between the back surface 21b corresponding to a part of the cut second main surface 210b and the mounting surface 22a of the circuit element 22, the light receiving element 21 and the circuit element 22 are electrically and physically connected in a state where the support member 400a is provided on the front surface 21a (fourth step). The plurality of bump electrodes 15 are provided on the mounting surface 22a of the circuit element 22. The light receiving element 21 and the circuit element 22 are electrically and physically connected by bonding a pair of opposing bump electrodes 13 and 15 in the Z-axis direction by pressurization and heating.

[0062] Subsequently, as shown in FIG. 24, the support member 400a is removed from the front surface 21a (fifth step). The support member 400a is peeled off from the front surface 21a by reducing the adhesive strength of the adhesive disposed between the light receiving element 21 and the support member 400a, for example, by light irradiation, heating, dissolution by a chemical solution, or the like. The adhesive remaining on the front surface 21a of the light receiving element 21 is removed from the front surface 21a, for example, by dissolution by a chemical solution, decomposition by a dry process, peeling by a tape, or the like. Thus, the photodetection device 20 is obtained. [Operation and Effect]

[0063] In the method for manufacturing the photodetection device 20, with the support substrate 400 provided on the first main surface 210a of the semiconductor wafer 210, the semiconductor wafer 210 and the support substrate 400 are cut for each of the plurality of light-receiving regions 21R. With the support member 400a provided on the surface 21a of the light-receiving element 21, the light-receiving element 21 and the circuit element 22 are electrically and physically connected, and then the support member 400a is removed from the surface 21a of the light-receiving element 21. In this way, when connecting the light-receiving element 21 and the circuit element 22, the support member 400a is provided on the surface 21a of the light-receiving element 21. Therefore, even if the light-receiving element 21 is thinned, it is possible to prevent the handling of the light-receiving element 21 from becoming difficult. Thus, according to the method for manufacturing the photodetection device 20, even if the light-receiving element 21 is thinned, the connection between the light-receiving element 21 and the circuit element 22 can be reliably performed.

[0064] Also, in the method for manufacturing the photodetection device 20, the plurality of light-receiving regions 21R are two-dimensionally arranged on the first main surface 210a side with respect to the semiconductor substrate 210s included in the semiconductor wafer 210. As a result, in the light-receiving element 21, the light-receiving regions 21R are arranged on the side opposite to the circuit element 22 with respect to the semiconductor substrate 210s, so that a photodetection device 20 including a surface-incident type light-receiving element 21 can be obtained.

[0065] Also, in the method for manufacturing the photodetection device 20, before cutting the semiconductor wafer 210 and the support substrate 400 for each of the plurality of light-receiving regions 21R, the semiconductor wafer 210 is thinned with the support substrate 400 provided on the first main surface 210a. Thereby, the semiconductor wafer 210 can be thinned in a stable state.

[0066] Also, in the method for manufacturing the photodetection device 20, a plurality of bump electrodes 13 are provided on the second main surface 210b of the semiconductor wafer 210 with the support substrate 400 provided on the first main surface 210a. Thereby, a plurality of bump electrodes 13 can be efficiently provided for each of the plurality of light-receiving regions 21R.

[0067] In the light detection device 20, the height of each of the plurality of bump electrodes 13 that electrically and physically connect the light receiving element 21 and the circuit element 22 is greater than the width of the light receiving element 21 in the direction perpendicular to the surface 21a. As a result, even if the light receiving element 21 is thinned and is likely to be deformed due to the influence of stress, static electricity, etc., the light receiving element 21 is prevented from contacting the circuit element 22. Therefore, according to the light detection device 20, even if the light receiving element 21 is thinned, it is possible to prevent the light receiving element 21 from being damaged due to deformation.

[0068] In the light detection device 20, the light receiving element 21 and the circuit element 22 are electrically and physically connected by a plurality of bump electrodes 13. As a result, while preventing the light receiving element 21 from contacting the circuit element 22, the connection between the light receiving element 21 and the circuit element 22 can be surely implemented.

[0069] In the light detection device 20, an underfill 14 is disposed between the back surface 21b of the light receiving element 21 and the mounting surface 22a of the circuit element 22. As a result, while protecting the plurality of bump electrodes 13, the connection between the light receiving element 21 and the circuit element 22 can be strengthened.

[0070] In the light detection device 20, the width of the light receiving element 21 in the direction parallel to the surface 21a is 10 times or more the width of the light receiving element 21 in the direction perpendicular to the surface 21a. In this way, even when the light receiving element 21 is thinned and has a large area, it is possible to prevent the light receiving element 21 from being damaged due to deformation. [Modification Example]

[0071] The present invention is not limited to the above-described embodiments. For example, the bonding between the semiconductor wafer 110 and the support substrate 300, the bonding between the semiconductor wafer 110 and the support substrate 400, and the bonding between the semiconductor wafer 210 and the support substrate 400 are not limited to bonding using an adhesive, and may be, for example, direct bonding or the like. Further, each of the support substrates 300 and 400 is not limited to a glass substrate, and may be, for example, a silicon substrate or the like. As an example, when the support substrate 300, which is a silicon substrate, is bonded to the semiconductor wafer 110 by direct bonding, the support substrate 300 may be removed from the semiconductor wafer 110 by decomposing the support substrate 300 itself by a dry process (gas). The same applies to the support substrate 400.

[0072] In the manufacturing method of each of the photodetection devices 10 and 20, the timing of arranging the underfill 14 can be appropriately selected. That is, before cutting each of the semiconductor wafers 110 and 210, a film-shaped underfill 14 may be arranged on each of the semiconductor wafers 110 and 210, or a film-shaped underfill 14 may be arranged on the circuit board 12 or the circuit element 22. Further, before cutting each of the semiconductor wafers 110 and 210, a film-shaped underfill 14 may be arranged on each of the light receiving elements 11 and 21, or a film-shaped underfill 14 may be arranged on the circuit board 12 or the circuit element 22. Further, after mounting the light receiving element 11 on the circuit board 12, a liquid underfill 14 may be filled between the light receiving element 11 and the circuit board 12 to cure the underfill, or after mounting the light receiving element 21 on the circuit element 22, a liquid underfill 14 may be filled between the light receiving element 21 and the circuit element 22 to cure the underfill. These may be either before or after removing the support member 400a from each of the light receiving elements 11 and 21.

[0073] Note that the method for manufacturing the photodetection device of the present invention is not limited to manufacturing a photodetection device in which the height of each of the plurality of bump electrodes 13 is greater than the width of the light receiving element 11 in the direction perpendicular to the back surface 11a, and a photodetection device in which the height of each of the plurality of bump electrodes 13 is greater than the width of the light receiving element 21 in the direction perpendicular to the front surface 21a.

[0074] In the photodetection device 10, the light receiving region 11R may include one or more light receiving channels, and the light receiving element 11 may be, for example, a light receiving element such as a SiPM (Silicon Photomultiplier) in which a plurality of avalanche photodiodes are connected in parallel. Also, in the photodetection device 10, the height of each of the plurality of bump electrodes 13 may be twice or more (or 2.5 times or more) the width of the light receiving element 11 in the direction perpendicular to the back surface 11a. Thereby, even if the light receiving element 11 is thinned, it is possible to more reliably prevent the light receiving element 11 from contacting the circuit board 12. Similarly, in the photodetection device 20, the height of each of the plurality of bump electrodes 13 may be five times or more the width of the light receiving element 21 in the direction perpendicular to the front surface 21a. Thereby, even if the light receiving element 21 is thinned, it is possible to more reliably prevent the light receiving element 21 from contacting the circuit element 22. Also, the bump electrode 13 may be, for example, a protruding electrode such as an Au bump, a solder bump, or a Cu pillar. Further, as a connecting member other than the bump electrode 13, for example, an anisotropic conductive film, an anisotropic conductive paste, or the like may be used. Furthermore, by combining these connecting members, an electrical and physical connection between the light receiving element 11 and the circuit board 12, and an electrical and physical connection between the light receiving element 21 and the circuit element 22 may be implemented. Also, the connecting member of the present invention may be constituted only by the bump electrode 13 provided on the light receiving element 11 or light receiving element 21 side, only by the bump electrode 15 provided on the circuit board 12 or circuit element 22 side, or may be constituted by the bump electrode 13 and the bump electrode 15 joined to each other.

Description of Reference Numerals

[0075] 10…Photo-detection device, 11…Light-receiving element, 11a…Back surface (first surface), 11b…Front surface (second surface), 11R…Light-receiving region, 12…Circuit board (circuit structure), 12a…Mounting surface, 13…Bump electrode (connecting member), 14…Underfill, 20…Photo-detection device, 21…Light-receiving element, 21a…Front surface (first surface), 21b…Back surface (second surface), 21R…Light-receiving region, 22…Circuit element (circuit structure), 22a…Mounting surface, 110…Semiconductor wafer, 110a…First main surface, 110b…Second main surface, 110s…Semiconductor substrate, 210…Semiconductor wafer, 210a…First main surface, 210b…Second main surface, 210s…Semiconductor substrate, 300…Support substrate (second support substrate), 400…Support substrate (first support substrate), 400a…Support member.

Claims

1. A step of preparing a semiconductor wafer having a first main surface and a second main surface opposite to the first main surface, and having a plurality of light-receiving regions arranged two-dimensionally; After the step of preparing the semiconductor wafer, a step of providing a first support substrate on the first main surface; After the step of providing the first support substrate on the first main surface, a step of providing a plurality of bump electrodes on the second main surface; After the step of providing the plurality of bump electrodes, a step of disposing an underfill on the second main surface so as to straddle the plurality of bump electrodes; After the step of disposing the underfill, with the first support substrate provided on the first main surface, cutting the semiconductor wafer and the first support substrate together with the underfill for each of the plurality of light-receiving regions, and obtaining a light-receiving element corresponding to a part of the cut semiconductor wafer in a state where a support member corresponding to a part of the cut first support substrate is provided on a first surface corresponding to a part of the cut first main surface; After the step of obtaining the light-receiving element, using the plurality of bump electrodes disposed between a second surface corresponding to a part of the cut second main surface and a mounting surface of a circuit structure, electrically and physically connecting the light-receiving element and the circuit structure by pressure and heating in a state where the support member is provided on the first surface; After the step of electrically and physically connecting the light-receiving element and the circuit structure, a step of removing the support member from the first surface, a method for manufacturing a photodetection device.

2. The method for manufacturing a photodetection device according to claim 1, wherein the plurality of light-receiving regions are arranged two-dimensionally on the second main surface side with respect to a semiconductor substrate included in the semiconductor wafer.

3. The method for manufacturing a photodetection device according to claim 1, wherein the plurality of light-receiving regions are arranged two-dimensionally on the first main surface side with respect to a semiconductor substrate included in the semiconductor wafer.

4. After the step of providing the first support substrate on the first main surface and before the step of obtaining the light receiving element, the method for manufacturing a photodetection device according to claim 3 further comprises a step of thinning the semiconductor wafer in a state where the first support substrate is provided on the first main surface.

5. The step of disposing the underfill is performed after the step of thinning the semiconductor wafer and before the step of electrically and physically connecting the light receiving element and the circuit structure, the method for manufacturing a photodetection device according to claim 4.

6. Before the step of obtaining the light receiving element, the method for manufacturing a photodetection device according to claim 4 or 5 further comprises a step of forming a wiring in a through hole of the semiconductor wafer.

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