JP2013084880A - Solid state imaging device, solid state imaging element, and method for manufacturing solid state imaging element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid state imaging device, a solid state imaging element, and a method for manufacturing the solid state imaging element that are capable of improving image quality.SOLUTION: A solid state imaging device comprises: a sensor substrate curved such that an upper face with a plurality of pixels formed thereon is recessed; and an imaging lens provided on the upper face side.

Description

  Embodiments described herein relate generally to a solid-state imaging device, a solid-state imaging device, and a method for manufacturing the solid-state imaging device.

In a solid-state imaging device in which a microlens array is configured through an air gap of several tens of μm on a sensor substrate having a plurality of pixels formed on the upper surface, high parallelism between the sensor substrate and the microlens array is required.
In general, therefore, a microlens array is formed directly on the upper surface of the sensor substrate. Thereby, the parallelism between the pixel and the microlens is maintained.

  On the other hand, in a solid-state imaging device intended to detect the distance between the solid-state imaging device and a subject, the microlens array is arranged away from the sensor substrate on which the pixels are formed. However, if a variation of about several tens of μm occurs in the interval between the sensor substrate and the microlens array in a plane parallel to the upper surface of the sensor substrate, the optical axes of the imaging lens and the microlens are displaced, resulting in image quality. Cause a decline. Also, there is a problem in that the light collected through the adjacent microlens is incident on the pixel, and light color mixing occurs, thereby reducing the matching accuracy of the image group with parallax.

  In addition, the image plane of an object on a plane perpendicular to the optical axis is not necessarily a plane perpendicular to the optical axis, and is generally a curved surface. This phenomenon is called field curvature aberration, and the image position shifts as it goes to the periphery of the field of view, and the image periphery deteriorates.

JP 2001-061109 A

  Embodiments of the present invention provide a solid-state imaging device, a solid-state imaging device, and a manufacturing method of the solid-state imaging device that can achieve high image quality.

  The solid-state imaging device according to the embodiment includes a sensor substrate that is curved so that an upper surface on which a plurality of pixels are formed is depressed, and an imaging lens that is provided on the upper surface side.

  The solid-state imaging device according to the embodiment includes a solid-state imaging element having an imaging element that is curved so that the upper surface is depressed, and an imaging lens provided on the upper surface side.

  Furthermore, the solid-state imaging device according to the embodiment includes an imaging device that is curved so that the upper surface is recessed.

  Furthermore, the method for manufacturing a solid-state imaging device according to the embodiment includes a step of forming a plurality of pixels on an upper surface of a semiconductor substrate, a multilayer wiring layer connected to the pixels on the semiconductor substrate, and covering the multilayer wiring layer Forming a step of forming an interlayer insulating film; removing a lower portion of the semiconductor substrate; and bending the upper surface of the semiconductor substrate.

1 is a cross-sectional view illustrating a solid-state imaging device according to a first embodiment. (A) is a top view which illustrates the microlens array substrate in 1st Embodiment, (b) is a top view which illustrates the sensor substrate in 1st Embodiment. It is sectional drawing which illustrates the sensor board | substrate and microlens array board | substrate in 1st Embodiment. (A)-(d) is process sectional drawing which illustrates the manufacturing method of the solid-state imaging device which concerns on 2nd Embodiment. (A)-(e) is process sectional drawing which illustrates the manufacturing method of the solid-state imaging device which concerns on 3rd Embodiment. (A)-(e) is process sectional drawing which illustrates the manufacturing method of the solid-state imaging device which concerns on 4th Embodiment. It is sectional drawing which illustrates the solid-state imaging device which concerns on 5th Embodiment. (A)-(f) is process sectional drawing which illustrates the manufacturing method of the solid-state imaging device which concerns on 6th Embodiment. (A)-(f) is process sectional drawing which illustrates the manufacturing method of the solid-state imaging device which concerns on 6th Embodiment. It is sectional drawing which illustrates the solid-state imaging device which concerns on 7th Embodiment. It is sectional drawing which illustrates the sensor board | substrate in the modification of 7th Embodiment. (A)-(c) is a top view which illustrates the sensor board | substrate in the modification of 7th Embodiment. It is a perspective view which illustrates the solid-state imaging device concerning an 8th embodiment. It is a perspective view which illustrates the solid-state imaging device concerning a 9th embodiment. (A) is sectional drawing which illustrates the solid-state imaging device which concerns on 10th Embodiment, (b) is sectional drawing which illustrates a solid-state image sensor in the solid-state imaging device which concerns on 10th Embodiment. . (A) And (b) is a figure which illustrates field curvature in the solid-state imaging device concerning a 10th embodiment. It is sectional drawing which illustrates the solid-state imaging device which concerns on the comparative example of 1st Embodiment. It is sectional drawing which illustrates the solid-state imaging device which concerns on 11th Embodiment. It is sectional drawing which illustrates the solid-state image sensor concerning 12th Embodiment. It is sectional drawing which illustrates the solid-state image sensor which concerns on 13th Embodiment. It is sectional drawing which illustrates the solid-state image sensor concerning 14th Embodiment. (A) is sectional drawing which illustrates the solid-state image sensor concerning 15th Embodiment, (b) is a bottom view which illustrates an image sensor in the solid-state image sensor concerning 15th Embodiment. It is sectional drawing which illustrates the solid-state image sensor concerning 16th Embodiment. It is sectional drawing which illustrates the solid-state image sensor concerning 17th Embodiment. It is sectional drawing which illustrates the solid-state image sensor concerning 18th Embodiment. It is sectional drawing which illustrates the solid-state image sensor concerning 19th Embodiment. (A)-(c) is process sectional drawing which illustrates the manufacturing method of the solid-state image sensor concerning 20th Embodiment. (A)-(d) is process sectional drawing which illustrates the manufacturing method of the solid-state image sensor concerning 21st Embodiment. It is a figure which illustrates the solid-state image sensor which concerns on 22nd Embodiment, (a) is a perspective view, (b) is sectional drawing by the A-A 'line | wire shown to (a). It is a figure which illustrates the solid-state image sensor concerning 23rd Embodiment, (a) is a perspective view, (b) is sectional drawing by the B-B 'line | wire shown to (a). It is a perspective view which illustrates the solid-state image sensing device concerning the modification of a 23rd embodiment. It is a figure which illustrates the solid-state image sensor concerning 24th Embodiment, (a) is a perspective view, (b) is sectional drawing by the C-C 'line | wire shown to (a). It is a figure which illustrates the solid-state image sensor concerning 25th Embodiment, (a) is a perspective view, (b) is sectional drawing by the D-D 'line | wire shown to (a). (A) And (b) is sectional drawing which illustrates the solid-state image sensor concerning the modification of 25th Embodiment. (A)-(c) is sectional drawing which illustrates the manufacturing method of the solid-state image sensor concerning 26th Embodiment. (A)-(f) is sectional drawing which illustrates the manufacturing method of the solid-state image sensor concerning 27th Embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
First, the first embodiment will be described.
FIG. 1 is a cross-sectional view illustrating a solid-state imaging device according to the first embodiment.
FIG. 2A is a plan view illustrating the microlens array substrate in the first embodiment, and FIG. 2B is a plan view illustrating the sensor substrate in the first embodiment.
FIG. 3 is a cross-sectional view illustrating a sensor substrate and a microlens array substrate in the first embodiment.

As shown in FIG. 1, the solid-state imaging device 1 according to this embodiment includes a driving / processing chip 22, a sensor substrate 12, a connection post 17, a microlens array substrate 14, a visible light transmission substrate 23, an optical filter 24, and a lens. A holder 26, a lens barrel 27, an imaging lens 25, and a light shielding cover 28 are provided.
The driving / processing chip 22 is provided with a plurality of through electrodes 58 penetrating the driving / processing chip 22. Bumps 21 are provided on the through electrodes 58. A sensor substrate 12 is provided on the driving / processing chip 22 so as to be in contact with the bumps 21.
A through electrode 19 is provided on the sensor substrate 12. The lower surface of the through electrode 19 provided on the sensor substrate 12 is disposed on the bump 21. Thereby, the sensor substrate 12 and the driving / processing chip 22 are connected. The upper surface of the through electrode 19 is connected to the electrode pad 20. The electrode pad 20 is used for reading out the pixel 11.

The sensor substrate 12 is obtained by forming a plurality of pixels 11, for example, photodiodes, on a semiconductor substrate 10, for example, a silicon substrate. The plurality of pixels 11 are provided in an array on the upper surface 9 of the sensor substrate 12.
A pixel condensing microlens 13 is provided on each pixel 11.
One end of a plurality of connection posts 17 is joined to the upper surface 9 of the sensor substrate 12. The microarray substrate 14 is bonded to the other ends of the plurality of connection posts 17. The microarray substrate 14 is formed using a transparent substrate, for example, a quartz plate. A plurality of microlenses 15 are formed on one surface of the microlens array substrate 14. The microlens array substrate 14 is arranged so that the surface of the microlens array substrate 14 on which the microlenses 15 are formed faces the upper surface 9 of the sensor substrate 12.
The peripheral portion of the sensor substrate 12 where the pixels 11 are not formed and the peripheral portion of the microlens array substrate 14 where the microlenses 15 are not formed are fixed to each other by the spacer resin 18.

  A visible light transmitting substrate 23 and an optical filter 24 are provided on the surface of the microlens array substrate 14 opposite to the sensor substrate 12. An imaging lens 25 is provided above the visible light transmitting substrate 23 and the optical filter 24. The imaging lens 25 is arranged so that the optical axis passes through a region where the microlens 15 is formed on the microlens array substrate 14 and a region where the pixel 11 is formed on the sensor substrate 12. The edge of the imaging lens 25 is supported by the lens barrel 27. The lens barrel 27 is attached to the lens holder 26 and fixed on the peripheral portion of the microlens array substrate 14. The light shielding cover 28 covers the bottom surface of the processing / driving chip and the side surfaces of the processing / driving chip 22, the sensor substrate 12, the spacer resin 18, the microlens array substrate 14, the visible light transmitting substrate 23, the optical filter 24, and the lens holder 26. It is provided as follows. The light shielding cover 28 is provided with a module electrode 29 that penetrates the bottom. The module electrode 29 is connected to the through electrode 58 of the processing / driving chip 22.

As shown in FIG. 2A, when one surface of the microlens array substrate 14 is viewed from the vertical direction, the shape of each microlens 15 is circular. The microlens 15 is two-dimensionally arranged on one surface of the microlens array substrate 14. For example, a hexagonal close-packed arrangement, that is, one microlens 15 is surrounded by six microlenses and arranged in contact with the six microlenses.
One microlens 15 is larger than one pixel 11. Comparing the size of the microlens circle with the size of the pixel 11, for example, the size of one microlens 15 includes nine pixels 11 and 16 pixels 11 in the circle. Is a size that partially enters.

As shown in FIG. 2B, since the shape of the microlens 15 is circular when viewed from the incident direction of light, the upper surface 9 of the sensor substrate 12 is irradiated with the light transmitted through the microlenses 15 and condensed. The shape of the area 57 is circular. A group of pixels 11 arranged in the region 57 is defined as a pixel block 49. Each pixel block 49 is associated with each microlens 15.
On the upper surface 9 of the sensor substrate 12, there is a region 56 that is not irradiated with the light that has been transmitted through the microlenses 15 and collected. That is, the light that has been transmitted through and condensed by each microlens 15 does not enter the pixel 11 disposed in the region 56.

  One end of a connection post 17 is bonded to a region 16 between the microlenses 15 in the microlens array substrate 14. The other end of the connection post 17 is joined to a region 56 on the upper surface 9 of the sensor substrate 12.

As shown in FIG. 3, the sensor substrate 12 and the microlens array substrate 14 are coupled and supported by a connection post 17. The upper surface 9 of the sensor substrate 12 and one surface of the microlens array substrate 14 are kept parallel by the connection posts 17.
The connection post 17 includes, for example, a heat-soluble organic material. The connection post 17 includes a material that absorbs light in the visible wavelength range, for example, a black pigment. The black pigment includes, for example, one or more pigments selected from the group consisting of carbon black, pigment black 7, and titanium black.
The distance between the sensor substrate 12 and the microlens array substrate 14 is preferably 10 to 100 micrometers (μm).
Between the upper surface 9 of the sensor substrate 12 and the microlens array substrate 14, the gap between the connection posts 17 is an air gap 30, that is, a gap where gas exists.

Next, the operation of the solid-state imaging device 1 according to this embodiment will be described.
Light from the subject is collected by passing through the imaging lens 25 and is incident on the microlens array substrate 14. Of the light that has entered the microlens array substrate 14, the light that has reached the microlens 15 is transmitted through each microlens 15 and collected for each microlens 15, and on the upper surface 9 of the sensor substrate 12, for each microlens 15. Is imaged. That is, an image of the subject is formed for each pixel block 49 corresponding to each microlens 15. However, the viewpoints of these images are slightly different due to the difference in the arrangement position of the microlens 15. These images are sensed by a plurality of pixels 11 belonging to each pixel block 49. In this way, a plurality of images having parallax between each other are acquired by the number of microlenses 15.

Then, the parallax image group obtained from a large number of microlenses 15 is subjected to image processing to estimate the distance between the subject and the solid-state imaging device 1 based on the principle of triangulation. Also, one two-dimensional image is acquired by performing image processing for stitching.
The connection post 17 provided in the region 16 between the microlenses 15 prevents light transmitted through each microlens 15 from irradiating the pixel block 49 associated with another adjacent microlens 15.

Next, effects of the solid-state imaging device 1 according to the present embodiment will be described.
If the microlens array substrate 14 and the sensor substrate 12 are not kept parallel, the optical axis may be deviated and image quality may be degraded. In the solid-state imaging device 1 according to the present embodiment, since the space between the microlens array substrate 14 and the sensor substrate 12 is fixed by the connection posts 17, it can be kept parallel. Therefore, high image quality of the solid-state imaging device 1 can be realized.

  The connection posts 17 are provided in the region 16 between the microlenses 15 in the microlens array substrate 14. In addition, the connection post 17 is provided in a region 56 where light transmitted through the microlens 15 and condensed on the sensor substrate 12 does not enter. Since the area 56 does not contribute to imaging, it is a so-called dead space, the effective number of pixels is not reduced. Therefore, since it is not necessary to provide an extra area for the connection posts 17, the density of the microlenses 15 with respect to the microlens array substrate 14 and the density of the pixels 11 with respect to the sensor substrate 12 can be increased. Therefore, high image quality of the solid-state imaging device 1 can be realized.

  The connection post 17 includes a material that absorbs light in the visible wavelength range. Therefore, the pixel block 49 does not receive the light that has been transmitted and condensed through the microlenses 15 other than the microlens 15 associated with the pixel block 49. Therefore, color mixing can be prevented.

(Second Embodiment)
Next, a second embodiment will be described.
This embodiment relates to a method for manufacturing a solid-state imaging device.
4A to 4D are process cross-sectional views illustrating a method for manufacturing a solid-state imaging device according to the second embodiment.

  First, as shown in FIG. 4A, a pixel 11 and a peripheral circuit (not shown) are formed on the upper surface of a semiconductor substrate 10, for example, a silicon substrate. The pixel 11 is, for example, a photodiode. The pixel 11 and the peripheral circuit are formed by using, for example, a manufacturing process of CMOS (Complementary Metal Oxide Semiconductor). Thereby, the sensor substrate 12 is manufactured.

On the other hand, as shown in FIG. 4B, a transparent substrate such as a quartz plate is prepared as a material for the microlens array substrate 14. Then, the microlens 15 is formed on the transparent substrate by dry etching the transparent substrate.
In this way, the microlens array substrate 14 on which a plurality of microlenses 15 are formed is manufactured.

Then, as shown in FIG. 4C, when the microlens array substrate 14 is bonded to the region to be the region 56 (see FIG. 2) on the upper surface 9 of the sensor substrate 12, that is, the sensor substrate 12, A connection post 17 is formed in a region that is not irradiated with light transmitted through the microlens 15.
The connection posts 17 are formed by depositing a heat-soluble organic material on the sensor substrate 12 and then patterning by a lithography method. As a result, a connection post 17 having one end bonded to the upper surface 9 of the sensor substrate 12 is formed. The connection post 17 includes a material that absorbs light in the visible wavelength region.

Thereafter, as shown in FIG. 4D, the other end of the connection post 17 is joined to the region 16 between the microlenses 15 on the microlens array substrate 14 (see FIG. 2A).
Thereby, the structure shown in FIG. 3 is manufactured.

Further, the through electrode 19 is formed on the sensor substrate 12. Then, a reading electrode pad 20 of the pixel 11 is formed on the upper surface of the through electrode 19. Further, the lower surface of the through electrode 19 is connected to the bump 21. Next, the bump 21 and the through electrode 58 of the driving / processing chip 22 are joined. A visible light transmitting substrate 23 and an optical filter 24 are provided on the microlens array substrate 14.
Then, on the opposite side of the microlens array substrate 14 from the sensor substrate 12, a lens holder 26 is installed in a region where the pixels 11 are not formed. A lens barrel 27 to which the end of the imaging lens 25 is fixed is attached to the lens holder 26. At this time, the optical axis of the imaging lens 25 is made to pass through the microlens array substrate 14 and the sensor substrate 12. Thereafter, a light shielding cover 28 for blocking unnecessary light is attached so as to cover the driving / processing chip 22, the sensor substrate 12, the microlens array substrate 14, and the lens holder 26. Then, a module electrode 29 for connecting the driving / processing chip 22 and the outside is attached to the bottom of the light shielding cover 28.
In this way, the solid-state imaging device 1 shown in FIG. 1 is manufactured.

  The microlens 15 can be formed by bonding a microlens sheet formed of a transparent organic film to a transparent substrate. The microlens 15 can also be formed by imprinting a microlens sheet formed of a transparent organic film.

Next, the effect of this embodiment will be described.
According to the method for manufacturing the solid-state imaging device 1 according to the present embodiment, one end of the connection post 17 on the microlens array substrate 14 side is in the region 16 between the microlenses 15, and this region 16 is the microlens array substrate 14. It is a recessed part. Therefore, the connection posts 17 can be joined in a self-aligning manner. Therefore, the two-dimensional arrangement of the connection posts 17 can be realized with high accuracy.

(Third embodiment)
Next, a third embodiment will be described.
5A to 5E are process cross-sectional views illustrating a method for manufacturing a solid-state imaging device according to the third embodiment.
First, as shown in FIGS. 5A and 5B, the steps shown in FIGS. 4A and 4B in the second embodiment described above are performed. Explanation of these steps is omitted.

  Next, as shown in FIG. 5C, first connection posts 17 a are formed in a region 16 between the microlenses 15 in the microlens array substrate 14. The first connection post 17a is formed by depositing a heat-soluble organic material on the microlens array substrate 14 and then patterning it by a lithography method. The first connection post 17a includes a material that absorbs light in the visible wavelength region.

On the other hand, as shown in FIG. 5D, the second connection post 17 b is formed in the region 56 on the upper surface 9 of the sensor substrate 12. The second connection post 17b is formed by the process shown in FIG.
Then, as shown in FIG. 5E, the other end of the first connection post 17a formed on the microlens array substrate 14 and the other end of the second connection post 17b formed on the sensor substrate 12 are joined. .
Thereby, the solid-state image sensor 1 shown in FIG. 3 is manufactured.

Next, the effect of this embodiment will be described.
According to the method for manufacturing the solid-state imaging device 1 according to this embodiment, the first and second connection posts are formed in advance on both the sensor substrate 12 and the microlens array substrate 14 by the lithography method. Therefore, for example, the bonding position can be determined with high accuracy by a manufacturing method in which one end or the other end of the connection post 17 is bonded by bonding.

(Fourth embodiment)
Next, a fourth embodiment will be described.
6A to 6E are process cross-sectional views illustrating a method for manufacturing a solid-state imaging device according to the fourth embodiment.
First, as shown in FIGS. 6A and 6B, the steps shown in FIGS. 5A and 5B in the third embodiment described above are performed. Explanation of these steps is omitted.

Next, as shown in FIG. 6C, the step shown in FIG. 5C in the third embodiment is performed. Description of this process is omitted.
On the other hand, as shown in FIG. 6D, a recess 31 is formed on the upper surface of the sensor substrate 12. The recess 31 is formed by etching, for example. The position of the recess 31 is made to coincide with the position of the connection post 17 formed on the microlens array substrate 14. The width of the recess 31 is made to coincide with the width of the connection post 17.
Then, as shown in FIG. 6E, the other end of the connection post 17 is fitted into the recess 31.
Thereby, the solid-state image sensor 1 shown in FIG. 3 is manufactured.

Next, the effect of this embodiment will be described.
According to the solid-state imaging device according to the present embodiment, the depth of the other end of the connection post 17 to be fitted into the recess 31 can be adjusted. Therefore, the parallelism between the sensor substrate 12 and the microlens array substrate 14 can be adjusted. Further, since the connection post 17 is fitted in the recess 31, the bonding strength is increased.

(Fifth embodiment)
Next, a fifth embodiment will be described.
FIG. 7 is a cross-sectional view illustrating a solid-state imaging device according to the fifth embodiment.
As shown in FIG. 7, in the solid-state imaging device 2 according to the present embodiment, the focal point 45 of the imaging lens is on the imaging lens 25 side from the microlens array substrate 14. The light from the subject is collected by passing through the imaging lens 25 and collected at the focal point 45. The tip from the focal point 45 extends toward the microlens array substrate 14. Light from the subject enters the microlens 15a close to the optical axis 33 from a direction near to the surface of the microlens 15a. Then, the light condensed through the microlens 15 a reaches the pixel block 49 in a direction that is nearly perpendicular to the upper surface 9 of the sensor substrate 12.
On the other hand, light from the subject is incident on the microlens 15b in the peripheral portion of the microlens array substrate 14 away from the optical axis 33 at an angle greatly inclined from the perpendicular to the surface of the microlens 15b. Then, the light collected through the microlens 15 b reaches the pixel block 49 at an angle greatly inclined from the vertical with respect to the upper surface of the sensor substrate 12.

The connection posts 17 are provided so as to be inclined so as to match the angle at which the light transmitted through the microlenses 15 and collected with respect to the upper surface of the sensor substrate 12 reaches the pixel block 49. Accordingly, the connection post 17 is arranged such that the other end 34 of the connection post 17 faces the optical axis 33 side as the distance between the position of the one end 32 connected to the sensor substrate 12 and the optical axis 33 of the imaging lens 25 increases. Tilted. The angle formed by the direction of the optical axis 33 of the imaging lens 25 and the direction in which the connection post 17 extends increases as the distance between the one end 32 connected to the sensor substrate 12 and the optical axis 33 increases.
Other configurations and operations in the present embodiment are the same as those in the first embodiment.

Next, the effect of this embodiment will be described.
In the solid-state imaging device 2 according to the present embodiment, the light that has been transmitted through and condensed through each microlens 15 is inclined with respect to the upper surface of the sensor substrate 12 according to the distance from the optical axis 33.
According to the solid-state imaging device 2 according to the present embodiment, the connection posts 17 are provided so as to match the inclination of the light that has been transmitted through the respective microlenses 15 and collected. Therefore, the light collected through the microlens 15 is not prevented from forming an image on the pixel block 49 associated with the microlens 15.
In addition, the connection post 17 forms an image on the pixel block 49 associated with the microlens 15c adjacent to the microlens 15b by the light transmitted through the microlens 15b in the peripheral portion of the microlens array substrate 14 and condensed. To prevent. Therefore, since no color mixing occurs, high image quality of the solid-state imaging device 2 can be realized.

(Sixth embodiment)
Next, a sixth embodiment will be described.
The present embodiment is a method for manufacturing the solid-state imaging device 2 described above.
FIGS. 8A to 8F and FIGS. 9A to 9F are process cross-sectional views illustrating the method for manufacturing the solid-state imaging device according to the sixth embodiment.
First, as shown in FIGS. 8A and 8B, the steps shown in FIGS. 4A and 4B in the second embodiment are performed. Explanation of these steps is omitted.

Next, as shown in FIG. 8C, a sacrificial layer 35 is formed on the sensor substrate 12. Thereafter, the sacrificial layer 35 is patterned. The patterning is performed by forming a mask 37 having an opening 36 formed on the sacrificial layer 35 and etching the sacrificial layer 35 using the mask 37 as a mask. The sacrificial layer 35 is formed with a recess 38 a perpendicular to the upper surface of the sensor substrate 12.
Thereafter, as shown in FIG. 8D, the mask 37 is removed, and the material of the connection posts 17 is embedded in the recesses 38a.
Then, as shown in FIG. 8E, the sacrificial layer 35 is removed leaving the embedded material of the connection posts 17. As a result, a connection post 17 c having one end bonded to the sensor substrate 12 is formed.

  Next, as shown in FIG. 8F, a sacrificial layer 39 is formed on the sensor substrate 12 and the connection posts 17c. Thereafter, the sacrificial layer 39 is patterned. The patterning is performed by forming a mask 41 having an opening 40 formed on the sacrificial layer 39 and etching the sacrificial layer 39 using the mask 41 as a mask. The position of the opening 40 is shifted from the position of the opening 36. That is, when the openings 36 and 40 of the masks 37 and 41 are overlapped, the openings 36 and 40 are formed so as to partially overlap. By etching, a recess 38 b perpendicular to the upper surface of the sensor substrate 12 is also formed in the sacrificial layer 39. The recesses 38a and the recesses 38b are partially connected, although their positions are shifted. Therefore, the entire recess is an inclined recess.

Thereafter, as shown in FIG. 9A, the mask 41 is removed, and the material of the connection posts 17 is embedded in the recesses 38b.
Then, as shown in FIG. 9B, the sacrificial layer 39 is removed leaving the embedded material of the connection posts 17. Thereby, the connection post 17d having one end connected to the other end of the connection post 17c is formed. The connection post 17c and the connection post 17d are formed to be inclined as a whole.

  Next, as shown in FIG. 9C, a sacrificial layer 42 is formed on the sensor substrate 12 and the connection posts 17c and 17d. Thereafter, the sacrificial layer 42 is patterned. The patterning is performed by forming a mask 44 having an opening 43 formed on the sacrificial layer 42 and etching the sacrificial layer 42 using the mask 44 as a mask. Similarly to FIG. 8F described above, the positions of the openings 40 and 43 are shifted. By etching, a recess 38 c perpendicular to the upper surface 9 of the sensor substrate 12 is also formed in the sacrificial layer 42. However, although the positions of the recess 38b and the recess 38c are shifted, they are partially connected, so that the entire recess is inclined.

Thereafter, as shown in FIG. 9D, the mask 44 is removed, and the material of the connection posts 17 is embedded in the recesses 38c.
Then, as shown in FIG. 9E, the sacrificial layer 42 is removed leaving the material of the embedded connection posts 17. Thereby, the connection post 17e having one end connected to the other end of the connection post 17d is formed.
An inclined connection post 17 is formed by the connection posts 17c, 17d and 17e.
If the number of formations of the sacrificial layer is increased and the connection posts are chopped and formed, the joints on the side surfaces of the inclined connection posts 17 become inconspicuous.

Next, as shown in FIG. 9F, the step shown in FIG. 4D in the second embodiment described above is performed. Description of this process is omitted.
In this way, the solid-state imaging device 2 shown in FIG. 7 is manufactured.

Next, the effect of this embodiment will be described.
The inclined connection post 17 can be formed by the method for manufacturing the solid-state imaging device 2 according to the present embodiment. Therefore, color mixing can be prevented and high image quality of the solid-state imaging device 2 can be realized.

(Seventh embodiment)
Next, a seventh embodiment will be described.
FIG. 10 is a cross-sectional view illustrating a solid-state imaging device according to the seventh embodiment.
As shown in FIG. 10, in the solid-state imaging device 3 according to the present embodiment, the sensor substrate 12 is curved so that the upper surface 9 is recessed. On the other hand, the microlens array substrate 14 provided facing the upper surface 9 of the sensor substrate 12 is flat. The connection post 17 is bonded to the microlens array substrate 14 perpendicularly. Therefore, the length of the connection post 17 connected to the center of the upper surface 9 of the sensor substrate 12 is longer than the length of the connection post 17 connected to the periphery of the upper surface 9 of the sensor substrate 12.

An imaging lens 25 may be provided on the opposite side of the microlens array substrate 14 from the sensor substrate 12. Further, the connection post 17 may be tilted as in the solid-state imaging device 2 described above.
Further, the sensor substrate 12 may be curved so that the distance from the focal point 45 of the imaging lens 25 to each pixel 11 is equal to each other.

Next, the operation of the solid-state imaging device 3 according to this embodiment will be described.
In the solid-state imaging device 3 according to the present embodiment, the light from the subject passes through the peripheral portion of the imaging lens 25 and the peripheral portion of the microlens array substrate 14 and is focused on the pixel block 49. The difference between the length of the optical path and the length of the optical path when the light passes through the central portion of the imaging lens 25 and the central portion of the microlens array substrate 14 and is focused on the pixel block 49 is reduced. Yes.

Next, the effect of this embodiment will be described.
According to the solid-state imaging device 3 according to the present embodiment, since the sensor substrate 12 is curved, the light from the subject that has been transmitted through the imaging lens 25 and collected is reflected by the microlenses 15 on the upper surface of the sensor substrate 12. 9 uniformly reach the central region and the peripheral region. Therefore, it is possible to suppress the curvature of field and improve the image quality of the solid-state imaging device 3.

(Modification of the seventh embodiment)
FIG. 11 is a cross-sectional view illustrating a sensor substrate in a modification of the seventh embodiment.
12A to 12C are plan views illustrating a sensor substrate in a modification of the seventh embodiment.
As shown in FIG. 11, in order to curve the sensor substrate 51, the sensor substrate 51 is thinned. The thickness of the sensor substrate 51 is preferably 5 to 10 micrometers (μm).

  In the case of a semiconductor crystal that is easy to cleave, such as silicon, even if the thickness of the sensor substrate 51 is reduced, it may be broken without being bent depending on the crystal orientation. Therefore, a cut 46 is formed in the back surface 52 of the sensor substrate 51 opposite to the upper surface 9. Thereby, it becomes easy to curve the peripheral part of the sensor substrate 51 in the upward direction 47 so that the upper surface 9 is depressed. The cut 46 can be formed by patterning and etching an arbitrary shape on the back surface of the sensor substrate 51 by, for example, photolithography.

  Further, as a means for preventing the sensor substrate 51 from cracking, the sensor substrate 51 is coated with an organic film 48. As the organic film 48, one that transmits light in the visible wavelength region is used. For example, parylene (paraxylylene polymer) is formed by vapor deposition polymerization or the like so as to cover the sensor substrate 51. Parylene is a very chemically stable substance, inactive against various solvents and chemicals, has an electrically insulating property with a low dielectric constant, and has excellent mechanical and light transmission characteristics. Yes. Here, for example, parylene C or parylene N can be used as the parylene covering the sensor substrate 51.

As shown in FIG. 12A, a plurality of cuts 53 extending in one direction on the back surface of the sensor substrate 51 are formed on the back surface 52 of the sensor substrate 51.
As shown in FIG. 12 (b), in addition to the cuts 53, a plurality of cuts 54 extending in a direction orthogonal to the direction in which the cuts 53 extend are formed on the back surface 52 of the sensor substrate 51.
Furthermore, as shown in FIG. 12C, the back surface 52 of the sensor substrate 51 has a plurality of cross-shaped cuts 55 that intersect one direction on the back surface 52 and another direction orthogonal to the one direction. It is arranged on the matrix in one direction and the other.

Next, the effect of this modification will be described.
If the sensor substrate 51 in this modification is used, the solid-state imaging device 3 that is not easily broken even if the upper surface 9 is curved so as to be depressed can be obtained.
By covering the sensor substrate 51 with an organic film, the solid-state imaging device 3 can have water resistance, chemical resistance, gas impermeability, electrical insulation, and heat resistance.
Furthermore, the organic film is formed of parylene having a high film property. Therefore, the sensor substrate 51 can be covered uniformly. Also, by covering the sensor substrate 51 with parylene, the durability of the sensor substrate 51 against various solvents and chemicals can be improved. Furthermore, the insulation of the sensor substrate 51 can be improved and the mechanical strength can be increased. Moreover, even if it is covered with parylene, the sensor substrate 51 can transmit light in a sufficient visible wavelength range.
Furthermore, by forming the cuts 53, 54 and 55 on the back surface 52 of the sensor substrate 12, the sensor substrate can be easily bent without being broken.
The effects of the present modification other than those described above are the same as those of the seventh embodiment described above.

(Eighth embodiment)
Next, an eighth embodiment will be described.
FIG. 13 is a perspective view illustrating a solid-state imaging device according to the eighth embodiment.
As shown in FIG. 13, in the solid-state imaging device 4 according to the present embodiment, the sensor substrate 12 is curved so that the upper surface 9 is recessed. On the other hand, the microlens array substrate 14 provided to face the upper surface 9 of the sensor substrate 12 is flat. The connection post 17 may not be provided.
Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the seventh embodiment described above.

(Ninth embodiment)
FIG. 14 is a perspective view illustrating a solid-state imaging device according to the ninth embodiment.
As shown in FIG. 14, in the solid-state imaging device 5 according to this embodiment, the sensor substrate 12 is curved so that the upper surface 9 is recessed. An imaging lens 25 is provided on the upper surface 9 side of the sensor substrate 12. The sensor substrate 12 may be curved so that the distance from the focal point 45 of the imaging lens 25 to each pixel 11 is equal to each other.
The microlens array substrate 14 may not be provided.
Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the seventh embodiment described above.

(Tenth embodiment)
FIG. 15A is a cross-sectional view illustrating a solid-state imaging device according to the tenth embodiment, and FIG. 15B is a cross-sectional view illustrating a solid-state imaging device in the solid-state imaging device according to the tenth embodiment. It is.
FIGS. 16A and 16B are diagrams illustrating field curvature in the solid-state imaging device according to the tenth embodiment.

  As shown in FIGS. 15A and 15B, a module housing 110 is provided in the solid-state imaging device 101 according to the present embodiment. The module housing 110 is in the shape of a container having an open top. A mounting substrate 111 is provided inside the module housing 110. The mounting substrate 111 is disposed on the bottom surface inside the module housing 110.

The mounting substrate 111 is provided with a post-processing circuit 111a including a processing chip.
A spacer 112 is provided on the mounting substrate 111. The lower surface of the spacer 112 is in contact with the upper surface of the mounting substrate 111. The upper surface of the spacer 112 is recessed in a mortar shape. That is, the thickness of the peripheral portion of the spacer 112 increases as it approaches the edge of the spacer 112.

An imaging element 91 is provided on the upper surface of the spacer 112. The shape of the image sensor 91 is a film having a thickness of 50 micrometers (μm). The image sensor 91 is arranged in a curved shape along the shape of the depression on the upper surface of the spacer 112. Therefore, the upper surface of the image sensor 91 is curved so as to be recessed. When the thickness of the image sensor 91 is 0.1 to 50 micrometers (μm), it is easy to bend.
A spacer 112 is disposed between the lower surface of the image sensor 91 and the mounting substrate 111. A mounting substrate 111 is disposed below the image sensor 91. A device including the image sensor 91 is referred to as a solid-state image sensor 71. The solid-state image sensor 71 of this embodiment includes an image sensor 91, a mounting substrate 111, and a spacer 112.

  The image sensor 91 includes a semiconductor layer 114. The semiconductor layer 114 is provided with a photodiode serving as the pixel 115, a driving / reading circuit (not shown), and a pixel reading electrode pad 116. A conductive, for example, metallic wire 117 is connected to the pixel reading electrode pad 116 to lead out the wiring. The other end of the wire 117 is connected to the post-processing circuit 111 a on the mounting substrate 111.

  A visible light transmission filter 118, for example, an IRCF (infrared cut-off filter) is provided above the image sensor 91. The visible light transmission filter 118 is fixed to a side surface inside the module housing 110. The visible light transmission filter 118 is formed using a material that cuts unnecessary infrared light. An imaging lens 119 is provided above the visible light transmission filter 118. The optical axis 120 of the imaging lens 119 is disposed so as to intersect with the upper surface of the image sensor 91. The imaging lens 119 is attached to the lens holder 121 and is fixed to a side surface inside the module housing 110. A light shielding cover for shielding unnecessary light is attached around the solid-state imaging device 101 (not shown).

The amount by which the image sensor 91 is bent is determined based on the field curvature aberration described below.
The field curvature aberration is a phenomenon in which an image formed through the imaging lens 119 forms an image on a curved curved surface without forming an image on a plane perpendicular to the optical axis 120. Is curved so as to be concave in the direction of the imaging lens 119. That is, this is a phenomenon in which an image at a position farther from the optical axis 120 is shifted (falls) toward the imaging lens 119.

  As shown in FIGS. 16A and 16B, an imaging lens is formed on a plane 122 that includes an intersection 122a between the optical axis 120 and the upper surface of the image sensor 91 (not shown) and is perpendicular to the optical axis 120. The distance from the center 119a of the 119 to the peripheral portion 122b in the plane 122 is longer than the distance from the center 119a of the imaging lens 119 to the intersection 122a. Therefore, in the lens in which the field curvature aberration is not corrected, the position 123 where the image is formed in the peripheral portion 122b is shifted from the plane 122 to the imaging lens 119 side. Usually, the imaging surface of an image sensor such as a CMOS image sensor is a flat surface and is arranged perpendicular to the optical axis 120. Therefore, when an image is formed using a lens that is not corrected for field curvature, On the imaging plane, an image that is out of focus is formed as the distance from the center portion increases. The field curvature is an aberration close to astigmatism.

As shown in FIG. 16 (b), the field curvature can be explained by the Petzval sum.
The Petzval sum P is expressed by the following mathematical formula (1).
Here, n is the refractive index of the imaging lens 119, f is the focal length of the imaging lens, and N is the number of imaging lenses. From Equation (1), an arbitrary position 125 on the plane 122 and an amount q ′ deviated from the position 125 toward the imaging lens 119 are derived from Equation (2).
Here, y ′ represents the distance between the main optical axis 120 and the position 125, and n represents the refractive index of the imaging lens. The curvature for bending the image sensor 91 can be derived from the formulas (1) and (2). Thereby, the distance between an arbitrary point on the upper surface of the image sensor 91 and the plane 122 can be obtained using the refractive index of the imaging lens 119 and the focal length f of the imaging lens 119.

Next, the operation of the solid-state imaging device according to this embodiment will be described.
Light from the subject is collected by passing through the imaging lens 119 and imaged on the upper surface of the image sensor 91. An image formed through the imaging lens 119 is formed on a curved surface. The image sensor 91 is curved to match the curved surface. Therefore, an image that is formed through the imaging lens 119 is formed on the curved upper surface of the image sensor 91.
Information of each pixel 115 by the image formed on the image sensor 91 is sent from the pixel reading electrode pad 116 via the wire 117 to the post-processing circuit 111a on the mounting substrate 111 and processed.

Next, the effect of this embodiment will be described.
According to the present embodiment, curvature of field can be suppressed by curving the image sensor 91. Thereby, the image quality of the imaging output obtained from the solid-state imaging device 101 can be improved.
In addition, it is not necessary to increase the number of lenses for correcting field curvature aberration, and the solid-state imaging device 101 can be reduced in size, weight, and cost.
Furthermore, since no additional optical element is interposed, optical loss can be reduced, and optical crosstalk (color mixing) can be reduced.
The visible light transmission filter may be a film that cuts infrared light.

(Comparative example)
Next, a comparative example of the first embodiment will be described.
FIG. 17 is a cross-sectional view illustrating a solid-state imaging device according to a comparative example of the first embodiment.
As shown in FIG. 17, in the solid-state imaging device 101a in this comparative example, a curved surface shape corresponding to the field curvature aberration is formed between the imaging surface 119b of the imaging lens (not shown) and the imaging element 91. And a light transmission tube 131 connected thereto. The light transmitted through an imaging lens (not shown) forms an image on the transparent substrate 130 having a curved shape corresponding to the field curvature aberration. The formed image passes through the light transmission tube 131 and reaches the image sensor 91.
In this comparative example, a transparent substrate 130 having a curved shape and a light transmission tube 131 connected to the transparent substrate 130 are required. Therefore, the solid-state imaging device 101a cannot be reduced in size and weight. In addition, the production cost increases. Furthermore, it is necessary to match the position between the light transmission tube 131 and the image sensor 91 with high accuracy, and the number of manufacturing steps increases. Further, since the light passes through the transparent substrate 130 and the light transmission tube 131, an optical loss occurs.

(Eleventh embodiment)
Next, an eleventh embodiment will be described.
FIG. 18 is a cross-sectional view illustrating a solid-state imaging device according to the eleventh embodiment.
As shown in FIG. 18, in the solid-state imaging device 102 according to the present embodiment, a microlens array substrate 142 is provided between the imaging element 91 and the imaging lens 119. The microarray substrate 142 is formed using a transparent substrate, for example, a quartz plate. A plurality of microlenses 143 are formed on the microlens array substrate 142. The microlens array substrate 142 is disposed so that the surface of the microlens array substrate 142 on which the microlens 143 is formed is opposed to the upper surface of the image sensor 91. Further, the upper surface of the image sensor 91 and the microarray substrate 142 are separated from each other.

Next, the operation of the solid-state imaging device 102 according to this embodiment will be described.
Light from the subject is collected by passing through the imaging lens 119 and is incident on the microlens array substrate 142. Of the light that has entered the microlens array substrate 142, the light that has reached the microlens 143 passes through each microlens 143 and is collected for each microlens 143, and for each microlens 143 on the upper surface of the image sensor 91. Imaged. The distance to the subject is measured based on the image formed by each microlens 143. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the tenth embodiment described above.

(Twelfth embodiment)
Next, a twelfth embodiment will be described.
FIG. 19 is a cross-sectional view illustrating a solid-state imaging element according to the twelfth embodiment.
As shown in FIG. 19, the solid-state image sensor 72 according to the present embodiment includes an image sensor 91, a mounting substrate 111, and a spacer 112a. The spacer 112 a is disposed between the lower surface of the peripheral portion of the image sensor 91 and the mounting substrate 111. The peripheral part of the image sensor 91 is supported by the spacer 112a, but the center part of the solid-state image sensor 91 is not supported by the spacer 112a. A space is formed between the mounting substrate 111 and the central portion of the image sensor 91.

The image sensor 91 has a bridging configuration supported by the spacer 112. The image sensor 91 is stressed by the spacer 112 in the direction from the edge of the image sensor 91 toward the center. The wire 117 connects the pixel readout electrode pad 116 and the post-processing circuit 111a.
According to the present embodiment, since the cavity is formed below the central portion of the image sensor 91, heat dissipation is improved. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the tenth embodiment described above.

(13th Embodiment)
Next, a thirteenth embodiment will be described.
FIG. 20 is a cross-sectional view illustrating a solid-state imaging element according to the thirteenth embodiment.
As shown in FIG. 20, the solid-state image sensor 73 according to this embodiment includes an image sensor 91 and a flexible substrate 132. The flexible substrate 132 is disposed so as to contact the lower surface of the image sensor 91. By bending the flexible substrate 132 on which the image sensor 91 is arranged with an arbitrary curvature, the image sensor 91 can also be bent.
In the present embodiment, a pixel readout electrode pad 116 is provided on the lower surface of the image sensor 91. In addition, a so-called surface mount type in which an electrode is taken out from the pixel reading electrode pad 116 provided on the lower surface. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the tenth embodiment described above.
Note that the pixel reading electrode pad 116 may be provided on the upper surface of the imaging element 91 and wire bonding may be performed from the upper surface with the wire 117. Further, the image sensor 91 and the flexible substrate 132 may be joined.

(Fourteenth embodiment)
FIG. 21 is a cross-sectional view illustrating a solid-state imaging element according to the fourteenth embodiment.
As shown in FIG. 21, the solid-state imaging device 74 according to the present embodiment includes an imaging device 91 and a mounting substrate 111b. The shape of the mounting substrate 111b is a stepped shape having a plurality of steps on the upper surface. The upper surface of the mounting substrate 111b is the lowest at the central portion, and the height increases from the central portion to the edge at every step. The curved image sensor 91 is disposed on the mounting substrate 111b. The lower surface of the image sensor 91 is in contact with the step corner 111c on the upper surface of the mounting substrate 111b. For example, an organic adhesive is used for connection between the image sensor 91 and the mounting substrate 111b. The wire 117 connects the pixel readout electrode pad 116 and the post-processing circuit 111a. By increasing the level difference of the mounting substrate 111b, the amount by which the solid-state image sensor 91 is bent can be accurately controlled. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the tenth embodiment described above.

(Fifteenth embodiment)
Next, a fifteenth embodiment is described.
FIG. 22A is a cross-sectional view illustrating a solid-state image sensor according to the fifteenth embodiment, and FIG. 22B is a bottom view illustrating the image sensor in the solid-state image sensor according to the fifteenth embodiment. is there.
As shown in FIG. 22A, in the solid-state imaging device 75 of the present embodiment, the mounting substrate 111b has a stepped shape in which a plurality of steps are provided on the upper surface. In the mounting substrate 111, the electrode part 111d of the post-processing circuit 111a is provided on the upper surface of the central part, the corner part 111c, and the upper surface of the peripheral part. The pixel reading electrode pad 116 in the image sensor 91 is provided on the lower surface of the image sensor 91. A solder bump 140 is provided between the pixel readout electrode pad 116 and the electrode portion 111d. The solder bump 140 electrically connects the pixel reading electrode pad 116 and the electrode portion 111d. Inside the mounting substrate 11b, a lead wire 141 extending from the electrode portion 111d to the side surface of the mounting substrate 11b is provided. Electrical signals are taken in and out of the solid-state imaging device 75 via the lead wiring 141.

  As shown in FIG. 22B, a plurality of pixel readout electrode pads 116 are provided on the lower surface of the image sensor 91. A plurality of pixel readout electrode pads 116a arranged along the peripheral region on the lower surface of the image sensor 91 when viewed from below the image sensor 91 are so-called I / O electrodes, and lead wires 141 for inputting and outputting electric signals. It is connected to the. On the other hand, on the lower surface of the image sensor 91, the pixel readout electrode pad 116b disposed in the central region reinforces the physical connection with the mounting substrate 111b as a so-called dummy electrode.

  The solid-state imaging device 75 according to the present embodiment is provided with both a pixel readout electrode pad 116a serving as an I / O electrode and a pixel readout electrode pad 116b serving as a dummy electrode. Thereby, the image pickup element 91 can be supported at multiple points by utilizing the wettability of the solder in the solder bump 140. In addition, the image sensor 91 can be bent in a self-aligned manner by reflowing solder during mounting. Configurations, operations, and effects other than those described above in the present embodiment are the same as those in the tenth embodiment described above.

(Sixteenth embodiment)
FIG. 23 is a cross-sectional view illustrating a solid-state imaging element according to the sixteenth embodiment.
This embodiment relates to a surface irradiation type solid-state imaging device.
As shown in FIG. 23, the solid-state image sensor 76 according to the present embodiment includes an image sensor 92. The imaging element 92 is provided with a semiconductor layer 114. The semiconductor layer 114 is made of a semiconductor material such as silicon. A plurality of pixels 115 are formed on the semiconductor layer 114. The pixel 115 is, for example, a photodiode. When viewed from above the image sensor 92, the plurality of pixels 115 are provided in an array on the semiconductor layer 114.

A driving and reading circuit (not shown) is formed in the semiconductor layer 114.
A multilayer wiring layer 151 is provided on the semiconductor layer 114. The multilayer wiring layer 151 connects the pixels 115 and driving and readout circuits (not shown). An interlayer insulating film 150 is provided so as to cover the multilayer wiring layer 151. A color filter 152 is provided on the interlayer insulating film 150 in each pixel 115. A pixel condensing microlens 153 is provided on the color filter 152 in each pixel 115. The thickness of the image sensor 91 is 1 to 50 micrometers (μm), more preferably 1 to 10 micrometers (μm).

  According to the solid-state image sensor 76 according to the present embodiment, since the solid-state image sensor 76 is thin, the solid-state image sensor 76 can be curved. Thereby, field curvature aberration can be suppressed, and the image quality of the imaging output obtained from the imaging element 92 can be improved.

(Seventeenth embodiment)
Next, a seventeenth embodiment will be described.
FIG. 24 is a cross-sectional view illustrating a solid-state imaging element according to the seventeenth embodiment.
As shown in FIG. 24, the solid-state image sensor 77 of the present embodiment includes an image sensor 92. The image sensor 92 is coated with an organic film 154. The organic film 154 is transparent, that is, transmits light in the visible wavelength range. The organic film 154 is, for example, parylene. Parylene is a general term for paraxylylene polymers, and has a structure in which benzene rings are connected via CH2. The organic film 154 to be coated has a thickness of 0.1 to 10 micrometers (μm).

Next, the effect of this embodiment will be described.
The image sensor 92 includes a semiconductor layer 114. When single crystal silicon is used as the material of the semiconductor layer 114, cleavage and fracture occur along the crystal orientation of the semiconductor layer 114 only by applying a slight force to the image sensor 92.
According to this embodiment, the thinned imaging element 92 is coated with the organic film 154. Therefore, it is possible to reduce the load when the image sensor 92 is bent. Thereby, in the solid-state image sensor 77, it can curve, suppressing mechanical destruction.

  Parylene is a very chemically stable substance, is inert to various solvents and chemicals, has an electrically insulating property with a low dielectric constant, and has both mechanical and light transmission characteristics. Are better. Furthermore, the polymerized paraxylylene is a stable crystalline polymer, has high crystallinity, and is excellent in gap penetration. Therefore, the durability, insulation, mechanical characteristics, and light transmittance of the image sensor 92 can be improved. Other configurations and effects in the present embodiment are the same as those in the sixteenth embodiment described above.

(Eighteenth embodiment)
Next, an eighteenth embodiment will be described.
FIG. 25 is a cross-sectional view illustrating a solid-state imaging element according to the eighteenth embodiment.
This embodiment relates to a back-illuminated solid-state imaging device.
As shown in FIG. 25, the solid-state image sensor 78 according to this embodiment includes an image sensor 93. The imaging element 93 is provided with a semiconductor layer 114. A plurality of pixels 115 are formed below the semiconductor layer 114. When viewed from below the image sensor 93, the plurality of pixels 115 are provided in an array on the semiconductor layer 114.

A driving and reading circuit (not shown) is formed in the semiconductor layer 114.
A multilayer wiring layer 151 is provided on the lower surface of the semiconductor layer 114. An interlayer insulating film 150 is provided so as to cover the multilayer wiring layer 151.
A color filter 152 is provided on the upper surface of the semiconductor layer 114 in each pixel 115. A pixel condensing microlens 153 is provided on the color filter 152 in each pixel 115. The thickness of the image sensor 93 is 0.1 to 50 micrometers (μm), more preferably 1 to 10 micrometers (μm).

  In the solid-state imaging device 78 according to the present embodiment, the multilayer wiring layer 151 is provided on the side opposite to the surface on which light is incident. Therefore, incident light is not reflected by the multilayer wiring layer 151. Thereby, optical loss can be reduced. Other configurations, operations, and effects of the present embodiment are the same as those of the sixteenth embodiment described above.

(Nineteenth embodiment)
Next, a nineteenth embodiment will be described.
FIG. 26 is a cross-sectional view illustrating a solid-state imaging element according to the nineteenth embodiment.
As shown in FIG. 26, the solid-state image sensor 79 of the present embodiment includes an image sensor 93. The image sensor 93 is covered with an organic film 154. Also in this embodiment, the thickness of the organic film 154 to be coated is 0.1 to 10 micrometers. Other configurations, operations, and effects in the present embodiment are the same as those in the seventeenth embodiment described above.

(20th embodiment)
Next, a twentieth embodiment will be described.
27A to 27C are process cross-sectional views illustrating the method for manufacturing the solid-state imaging element according to the twentieth embodiment.
The present embodiment relates to a method for manufacturing the surface irradiation type solid-state imaging devices 76 and 77.

  First, as shown in FIG. 27A, a pixel 115 is formed on a semiconductor substrate 155, for example, a silicon substrate. The pixels 115 are formed in an array on the upper surface of the semiconductor substrate 155 when viewed from above the semiconductor substrate 155. In addition, a driving and reading circuit (not shown) is formed on the semiconductor substrate 155. Then, on the semiconductor substrate 155, a multilayer wiring layer 151 that connects the pixels 115 and driving and reading circuits and an interlayer insulating film 150 that covers the multilayer wiring layer are formed. Thereafter, the color filter 152 is disposed on the interlayer insulating film 150 in each pixel 115. Then, a pixel condensing microlens 153 is disposed on the color filter 152 in each pixel 115.

  Next, as illustrated in FIG. 27B, a support substrate 157 is bonded to the upper surface of the semiconductor substrate 155 with an adhesive layer 156 interposed therebetween. The support substrate 156 is, for example, quartz or silicon. For the adhesive layer 156, an adhesive that can be peeled off by light, heat, or a solvent is used.

  Next, as shown in FIG. 27C, the lower portion of the semiconductor substrate 155 is removed, and the semiconductor substrate 155 is thinned. Thinning is performed by back grinding or CMP (chemical mechanical polishing). As a result, the semiconductor substrate 155 is thinned to become the semiconductor layer 114. In this way, the image sensor 92 is formed.

Then, the image sensor 92 is peeled off from the support substrate 157. For the peeling of the support substrate 157, at least one method selected from the group consisting of peeling by irradiation with ultraviolet light (UV), peeling by heat treatment, and peeling by a solvent is used.
In this way, as shown in FIG. 23, the above-described solid-state imaging device 76 according to the sixteenth embodiment is manufactured.

Thereafter, the image sensor 92 may be coated with the organic film 154. The organic film 154 is, for example, parylene. A vapor deposition method is used for coating parylene. The coating thickness is 0.1 to 10 micrometers. Thereby, as shown in FIG. 24, the solid-state imaging device 77 according to the seventeenth embodiment described above is manufactured.
According to the present embodiment, the thin-film solid-state imaging devices 76 and 77 can be manufactured. Therefore, the solid-state image sensors 76 and 77 can be curved. Thereby, field curvature aberration can be suppressed, and the image quality of the imaging output obtained from the solid-state imaging devices 76 and 77 can be improved.

(21st Embodiment)
Next, a twenty-first embodiment will be described.
FIGS. 28A to 28D are process cross-sectional views illustrating the method for manufacturing the solid-state imaging element according to the twenty-first embodiment.
The present embodiment relates to a method for manufacturing back-illuminated solid-state imaging elements 78 and 79.

  First, as shown in FIG. 28A, the pixel 115 is formed on the semiconductor substrate 155. The pixels 115 are formed in an array on the upper surface of the semiconductor substrate 155 when viewed from above the semiconductor substrate 155. In addition, a driving and reading circuit (not shown) is formed on the semiconductor substrate 155. Then, a multilayer wiring layer 151 and an interlayer insulating film 150 that connect the pixels 115 and driving and reading circuits are formed on the semiconductor substrate 155.

Next, as illustrated in FIG. 28B, a support substrate 157 is bonded to the upper surface of the semiconductor substrate 155 with an adhesive layer 156 interposed therebetween.
Next, as shown in FIG. 28C, the lower portion of the semiconductor substrate 155 is removed by shaving, and the semiconductor substrate 155 is thinned. The semiconductor substrate 155 is thinned to become the semiconductor layer 114.

  Next, as illustrated in FIG. 28D, the color filter 152 is disposed on the lower surface of the semiconductor layer 114 in each pixel 115. In FIG. 28D, the semiconductor layer 114 and the support substrate 157 in FIG. 28C are shown upside down. Then, a pixel condensing microlens 153 is disposed on the lower surface of the color filter 152 in each pixel 115. Thereby, the image sensor 93 is formed.

Next, the image sensor 93 is peeled off from the support substrate 157. In this way, as shown in FIG. 25, the above-described solid-state imaging device 78 according to the eighteenth embodiment is manufactured.
After that, the solid-state imaging device 79 according to the nineteenth embodiment described above may be obtained by coating the imaging device 93 with the organic film 154 as shown in FIG.
According to this embodiment, the thin-film solid-state imaging elements 78 and 79 can be manufactured. Therefore, the solid-state image sensors 78 and 79 can be curved. Thereby, the field curvature aberration can be suppressed, and the image quality of the imaging output obtained from the solid-state imaging elements 78 and 79 can be improved.

(Twenty-second embodiment)
Next, a twenty-second embodiment will be described.
29A and 29B are diagrams illustrating a solid-state imaging device according to the twenty-second embodiment. FIG. 29A is a perspective view, and FIG. 29B is a cross-sectional view taken along line AA ′ shown in FIG.

As shown in FIGS. 29A and 29B, in the solid-state imaging device 80 according to the present embodiment, a notch 160 is formed in the surface 114b of the semiconductor layer 114 opposite to the surface 114a on which the interlayer insulating film 150 is provided. Is formed. A direction from the surface 114a to the surface 114b is defined as an upward direction. The notch 160 has a cross shape when viewed from above. That is, the notch 160 extends in one direction and the other direction intersecting the one direction in the surface 114b. The notch 160 does not penetrate the semiconductor layer 114. In the region immediately below the notch 160, the remaining white of the semiconductor layer 114 remains.
When the thin-film solid-state imaging device 80 is curved, the stress becomes large at the most curved maximum displacement portion. In addition, distortion increases at the maximum displacement portion.

  According to the present embodiment, by forming a cut in the semiconductor layer 114, it is possible to relieve stress and strain generated when the solid-state imaging device 80 is bent. By adopting a cross shape, stress and strain in one direction and the other direction can be relaxed. Other configurations, operations, and effects of the present embodiment are the same as those of the sixteenth embodiment described above.

(23rd embodiment)
Next, a twenty-third embodiment will be described.
30A and 30B are diagrams illustrating a solid-state imaging device according to the twenty-third embodiment. FIG. 30A is a perspective view, and FIG. 30B is a cross-sectional view taken along line BB ′ shown in FIG.
As shown in FIGS. 30A and 30B, the notches 160 of the solid-state imaging device 81 according to the present embodiment are formed into a plurality of straight lines extending in one direction when viewed from above on the surface 114b. Yes.
According to the present embodiment, it is possible to relieve stress and strain that are generated when bending is performed in a direction intersecting one direction, for example, in a direction orthogonal to one direction. Other configurations, operations, and effects of the present embodiment are the same as those of the twenty-second embodiment described above.

(Modification of the 23rd embodiment)
FIG. 31 is a perspective view illustrating a solid-state imaging device according to a modification of the twenty-third embodiment.
As shown in FIG. 31, the cut 160 of the solid-state imaging device 81a according to the present modification is formed in an annular shape, for example, a concentric shape, on the surface 114b. A concentric square shape may be used instead of the concentric shape. Other configurations, operations, and effects of the present embodiment are the same as those of the twenty-second embodiment described above.

(24th Embodiment)
Next, a twenty-fourth embodiment will be described.
FIGS. 32A and 32B are diagrams illustrating a solid-state imaging device according to the twenty-fourth embodiment. FIG. 32A is a perspective view, and FIG. 32B is a cross-sectional view taken along the line CC ′ shown in FIG.
As shown in FIGS. 32A and 32B, the solid-state imaging device 82 according to this embodiment is an embodiment in which the solid-state imaging device 80 according to the twenty-second embodiment is coated with an organic film 154. By coating with the organic film 154 in addition to the cross notch 160, it is possible to relieve stress and strain when bent in one direction and the other direction, and to suppress mechanical breakdown. Other configurations, operations, and effects of the present embodiment are the same as those of the twenty-second embodiment described above.

(25th Embodiment)
Next, a twenty-fifth embodiment is described.
33A and 33B are diagrams illustrating a solid-state imaging device according to the twenty-fifth embodiment. FIG. 33A is a perspective view, and FIG. 33B is a cross-sectional view taken along line DD ′ shown in FIG.
As shown in FIGS. 33A and 33B, the solid-state imaging device 83 according to this embodiment is an embodiment in which the solid-state imaging device 81 according to the twenty-third embodiment described above is coated with an organic film 154. It is possible to relieve stress and strain generated when bending in a direction orthogonal to one direction, and to suppress mechanical destruction. Other configurations, operations, and effects of the present embodiment are the same as those of the twenty-second embodiment described above.

(Modification of 25th Embodiment)
Next, a modification of the twenty-fifth embodiment will be described.
34A and 34B are cross-sectional views illustrating a solid-state imaging device according to a modification of the twenty-fifth embodiment.
As shown in FIG. 34A, in the solid-state imaging device 83a according to the modification of the twenty-fifth embodiment, the organic film 154 is formed on the surface 114b and may not be formed on the surface 114a.
Further, as shown in FIG. 34B, the organic film 154 is formed on the surface 114a and may not be formed on the surface 114b.
According to this modification, by forming the organic film 154 on one surface of the semiconductor layer 114, the stress and strain when the solid-state imaging element 83a is curved can be relaxed.

(26th Embodiment)
Next, a twenty-sixth embodiment will be described.
FIGS. 35A to 35C are cross-sectional views illustrating the method for manufacturing the solid-state imaging element according to the twenty-sixth embodiment.
First, similarly to the twentieth embodiment described above, the steps shown in FIGS. 27A to 27C are performed. Explanation of these steps is omitted.

Next, as shown in FIG. 35A, a cut 160 is formed in the lower surface of the semiconductor layer 114 in the solid-state imaging device 76. Thereby, the solid-state image sensor 81 is formed. In FIG. 35A, the solid-state image sensor 81 is shown upside down. The notches 160 have, for example, a shape of a plurality of grooves 161 extending in one direction. The groove 161 is formed by photolithography and etching processes. When the groove 161 is formed in silicon, for example, it can be formed by dry etching using sulfur hexafluoride (SF ₆ ). The depth of the groove 161 is controlled by the etching time and the gas flow rate.

Next, as shown in FIG. 35 (b), the solid-state imaging device 81 is peeled off from the support substrate 157. In this way, the solid-state imaging device 81 according to the twenty-third embodiment described above is manufactured.
Thereafter, as shown in FIG. 35 (c), the solid-state imaging device 83 may be formed by coating with an organic film 154.

(Twenty-seventh embodiment)
Next, a twenty-seventh embodiment will be described.
36A to 36F are cross-sectional views illustrating a method for manufacturing the solid-state imaging device according to the twenty-seventh embodiment.
First, similarly to the twenty-first embodiment described above, the process shown in FIG. Explanation of these steps is omitted.

Next, as shown in FIG. 36A, a cut 160 is formed in the upper surface of the interlayer insulating film 150. The notches 160 have, for example, a shape of a plurality of grooves 161 extending in one direction. The groove 161 is formed by photolithography and etching processes. When the trench 161 is formed in the interlayer insulating film 150 including the silicon oxide film, it can be formed by dry etching using, for example, tetrafluoromethane (CF ₄ ). The depth of the groove 161 is controlled by the etching time and the gas flow rate.

Next, as illustrated in FIG. 36B, a support substrate 157 is bonded to the upper surface of the semiconductor substrate 155 through an adhesive layer 156.
Next, as shown in FIG. 36C, the lower portion of the semiconductor substrate 155 is shaved to make the semiconductor substrate 155 thinner. The semiconductor substrate 155 is thinned to become the semiconductor layer 114.

  Next, as illustrated in FIG. 36D, the color filter 152 is disposed on the lower surface of the semiconductor layer 114 in each pixel 115. In FIG. 36D, the semiconductor layer 114 and the support substrate 157 are shown upside down. Then, a pixel condensing microlens 153 is disposed on the lower surface of the color filter 152 in each pixel 115. Thereby, the solid-state image sensor 84 is formed.

Next, as shown in FIG. 36 (e), the solid-state imaging device 84 is peeled off from the support substrate 157. In this way, the solid-state imaging device 84 is manufactured.
Thereafter, as shown in FIG. 36 (f), the solid-state imaging device 85 may be formed by coating with an organic film 154.

  According to the embodiments described above, it is possible to provide a solid-state imaging device, a solid-state imaging device, and a method for manufacturing the solid-state imaging device that can achieve high image quality.

  As mentioned above, although some embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of 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 scope of the invention described in the claims and the equivalents thereof. Further, the above-described embodiments can be implemented in combination with each other.

1: solid-state imaging device, 2: solid-state imaging device, 3: solid-state imaging device, 4: solid-state imaging device, 5: solid-state imaging device, 9: upper surface, 10: semiconductor substrate, 11: pixel, 12: sensor substrate, 13: Pixel condensing microlens, 14: microlens array substrate, 15: microlens, 16: region, 17: connection post, 17a: connection post, 17b: connection post, 17c: connection post, 17d: connection post, 17e: connection Post: 18: Spacer resin, 19: Through electrode, 20: Readout electrode pad, 21: Bump, 22: Driving / processing chip, 23: Visible light transmitting substrate, 24: Optical filter, 25: Imaging lens, 26: Lens holder, 27: Lens barrel, 28: Light shielding cover, 29: Module electrode, 30: Air gap, 31: Recess, 32: One end, 33: Optical axis, 34: Other , 35: sacrificial layer, 36: opening, 37: mask, 38a: recess, 38b: recess, 38c: recess, 39: sacrificial layer, 40: opening, 41: mask, 42: sacrificial layer, 43: opening 44: Mask, 45: Focus, 46: Cut, 47: Up direction, 48: Organic film, 49: Pixel block, 51: Sensor substrate, 52: Back side, 53: Cut, 54: Cut, 55: Cut, 56 : Region, 57: region, 58: penetrating electrode, 71: solid-state imaging device, 72: solid-state imaging device, 73: solid-state imaging device, 74: solid-state imaging device, 75: solid-state imaging device, 76: solid-state imaging device, 77: Solid-state imaging device, 78: Solid-state imaging device, 79: Solid-state imaging device, 80: Solid-state imaging device, 81: Solid-state imaging device, 82: Solid-state imaging device, 83: Solid-state imaging device, 84: Solid-state imaging device, 85: Solid-state imaging device Element, 91: Taken Element: 92: Imaging device, 93: Imaging device, 101: Solid-state imaging device, 101a: Solid-state imaging device, 102: Solid-state imaging device, 110: Module housing, 111: Mounting substrate, 111a: Subsequent processing circuit, 111b: Mounting Substrate, 111c: Corner, 111d: Electrode, 112: Spacer, 112a: Spacer, 114: Semiconductor layer, 114a: Surface, 114b: Surface, 115: Pixel, 116: Electrode pad for pixel readout, 116a: For pixel readout Electrode pad, 116b: Pixel reading electrode pad, 117: Wire, 118: Visible light transmission filter, 119: Imaging lens, 119a: Center, 120: Optical axis, 121: Lens holder, 122: Plane, 122a: Intersection 122b: peripheral part, 123: position, 124: position, 125 position, 126: position, 130: transparent base Plate: 131: Light transmission tube, 132: Flexible substrate, 140: Solder bump, 141: Lead-out wiring, 142: Microlens array substrate, 143: Microlens, 150: Interlayer insulating film, 151: Multilayer wiring layer, 152: Color Filter, 153: condenser lens, 154: organic film, 155: semiconductor substrate, 156: adhesive layer, 157: support substrate, 160: notch, 161: groove

Claims (27)

A sensor substrate that is curved so that an upper surface on which a plurality of pixels are formed is depressed;
An imaging lens provided on the upper surface side;
A solid-state imaging device.   The solid-state imaging device according to claim 1, wherein the sensor substrate is curved so that distances from the focal point of the imaging lens to the pixels are equal to each other.   The solid-state imaging device according to claim 1, wherein a cut is formed in a surface of the sensor substrate opposite to the upper surface.   The solid-state imaging device according to claim 1, wherein the material of the sensor substrate includes silicon.   The solid-state imaging device according to claim 1, wherein the sensor substrate is coated with an organic film.   The solid-state imaging device according to claim 5, wherein the organic film transmits light in a visible wavelength region.   The solid-state imaging device according to claim 5, wherein the organic film is parylene. A solid-state image sensor having an image sensor curved so that the upper surface is depressed;
An imaging lens provided on the upper surface side;
A solid-state imaging device.   The distance between one point on the upper surface of the curved imaging element and the plane perpendicular to the optical axis including the intersection of the optical axis of the imaging lens and the upper surface is the refractive index of the imaging lens and the The solid-state imaging device according to claim 8, which is determined using a focal length of the imaging lens.   The solid-state imaging device according to claim 9, wherein a distance at an edge of the upper surface is 10 nm to 1 mm.   The solid-state imaging device according to claim 8, further comprising a microlens array substrate provided between the solid-state imaging element and the imaging lens.   A solid-state imaging device including an imaging device curved so that an upper surface is depressed. A mounting board provided below the image sensor;
A spacer provided between the lower surface of the image sensor and the mounting substrate, the upper surface of which is depressed;
The solid-state imaging device according to claim 12, further comprising: A mounting board provided below the image sensor;
A spacer provided between the lower surface of the peripheral portion of the image sensor and the mounting substrate;
Further comprising
The solid-state imaging device according to claim 12, wherein a space is formed between a lower surface of a central portion of the imaging device and the mounting substrate.   The solid-state imaging device according to claim 12, further comprising a flexible substrate in contact with a lower surface of the imaging device, wherein the flexible substrate is curved together with the imaging device.   The solid-state imaging device according to claim 12, further comprising a stepped mounting substrate having a plurality of steps formed on an upper surface, wherein the lower surface of the solid-state imaging device is in contact with a corner of the step.   The solid-state imaging device according to claim 16, wherein a lower surface of the imaging device and the mounting substrate are connected via solder bumps.   The solid-state imaging device according to claim 17, wherein electrode pads arranged in a peripheral region on a lower surface of the imaging device are connected to a lead wiring in the mounting substrate.   The solid-state image sensor according to any one of claims 12 to 18, further comprising an organic film that coats the image sensor.   The solid-state image sensor according to any one of claims 12 to 19, wherein a cut is formed in a surface of the image sensor opposite to the upper surface.   21. The solid-state imaging device according to claim 20, wherein the cut extends in one direction on the opposite surface and in another direction intersecting with the one direction.   The solid-state image sensor according to any one of claims 12 to 21, wherein a thickness of the image sensor is 0.1 to 50 micrometers. Forming a plurality of pixels on the upper surface of the semiconductor substrate;
Forming a multilayer wiring layer connected to the pixel on the semiconductor substrate and an interlayer insulating film covering the multilayer wiring layer;
Removing a lower portion of the semiconductor substrate;
Bending the upper surface of the semiconductor substrate so as to be recessed;
Manufacturing method of solid-state image sensor provided with.   24. The method for manufacturing a solid-state imaging element according to claim 23, further comprising a step of forming a cut in the lower surface of the semiconductor substrate after the removing step. Forming a plurality of pixels on the lower surface of the semiconductor substrate;
Forming a multilayer wiring layer connected to the pixel on the lower surface of the semiconductor substrate and an interlayer insulating film covering the multilayer wiring layer;
Removing the upper portion of the semiconductor substrate;
Bending the upper surface of the semiconductor substrate so as to be recessed;
Manufacturing method of solid-state image sensor provided with.   26. The method of manufacturing a solid-state imaging device according to claim 25, further comprising a step of forming a cut in the interlayer insulating film after the step of forming the interlayer insulating film.   27. The solid according to claim 23, further comprising a step of coating the semiconductor substrate with an organic film after the step of removing the lower portion of the semiconductor substrate or the step of removing the upper portion of the semiconductor substrate. Manufacturing method of imaging device.