JP2012186271A - Solid state imaging device, method of manufacturing the same, and imaging module - Google Patents

Abstract

The present invention relates to a solid-state imaging device, a manufacturing method thereof, and an imaging module including the solid-state imaging device.
A solid-state imaging device in which a plurality of pixels are two-dimensionally arranged in an imaging area, a semiconductor substrate on which a photoelectric conversion unit is formed for each pixel, a semiconductor substrate formed on the semiconductor substrate, and on the photoelectric conversion unit A first refractive index film having a concave portion for each region, and a second refractive index film having a refractive index higher than the first refractive index partially embedded in the concave portion of the first refractive index film, The pixels include a first pixel in the central region of the imaging area and a second pixel in the peripheral region of the imaging area, and the upper surface of the second refractive index film in the second pixel is the first pixel A solid-state imaging device, wherein an end portion on a pixel side is inclined so as to be lower than an end portion on the side opposite to the first pixel side.
[Selection] Figure 3

Description

  The present invention relates to a solid-state imaging device, a method of manufacturing the same, and an imaging module including the solid-state imaging device, and more particularly to a waveguide structure that guides incident light to a photoelectric conversion unit.

  As an example of a conventional solid-state imaging device, for example, there is a charge coupled device (CCD) solid-state imaging device 900 as shown in FIGS. 11 is a cross-sectional view of the solid-state imaging device 900 along the horizontal transfer direction, and FIG. 12 is a cross-sectional view of the solid-state imaging device 900 along the vertical transfer direction. A solid-state imaging device 900 in which a plurality of pixels are two-dimensionally arranged in an imaging area is formed in an n-type semiconductor substrate 910, a p-type semiconductor well region 912 formed in the semiconductor substrate 910, and the semiconductor well region 912. Photodiodes 918 which are photoelectric conversion portions, transfer channels 922 which are formed in the semiconductor well region 912 and transfer charges generated by the photodiodes 918, transfer electrodes 932 and transfer electrodes 932 which are arranged corresponding to the respective photodiodes 918 And a connection wiring 936 that is electrically connected to the transfer electrode 932 through the contact 934.

  On the semiconductor well region 912, a cladding layer 940, which is a first refractive index film having a recess 940a in a region on the photodiode 918, and a refractive index higher than the refractive index of the cladding layer 940 embedded in the recess 940a of the cladding layer 940 A core layer 942 that is a second refractive index material film having a refractive index is formed. Further, a passivation film 960, a planarization film 962, a color filter 964, and a microlens 966 are stacked over the core layer 942.

  Here, a waveguide 944 is formed from the cladding layer 940 and the core layer 942. In other words, the light incident on the core layer 942 is difficult to enter the clad layer 940 made of a material having a refractive index lower than that of the material of the core layer 942, and is guided from the upper side in the stacking direction to the lower photodiode 918. 944 improves the light collection efficiency of the solid-state imaging device 900.

JP 2009-267252 A JP 2010-87039 A

  In general, light incident from a camera lens passes through a focal point and then spreads and enters a solid-state imaging device. Therefore, in a pixel in the central region of the imaging area, light enters from a substantially vertical direction and enters a peripheral region of the imaging area. In a certain pixel, light enters from an oblique direction. Therefore, in the conventional solid-state imaging device, there is a problem that the sensitivity of the solid-state imaging device is reduced in pixels in the peripheral region of the imaging area. As one of the factors, in the conventional solid-state imaging device, since the upper surface of the core layer and the upper surface of the semiconductor substrate are formed in parallel, in the pixels in the peripheral region, light is obliquely incident on the upper surface of the core layer. Incident light is incident at a large incident angle. When the incident angle of the light incident on the upper surface of the core layer is increased, the light is easily reflected on the upper surface of the core layer and the light transmitted to the inside of the core layer is reduced, so that the sensitivity in the pixels in the peripheral region is decreased.

  The present invention has been made to solve the above-described problem, and even in pixels in the peripheral region, light is not easily reflected on the upper surface of the core layer, and a solid that can suppress a decrease in sensitivity in the pixels in the peripheral region of the solid-state imaging device. It is an object of the present invention to provide an imaging device and a manufacturing method thereof.

  In order to achieve the above object, a solid-state imaging device according to the present invention is a solid-state imaging device in which a plurality of pixels are two-dimensionally arranged in an imaging area, and a semiconductor substrate in which a photoelectric conversion unit is formed for each pixel; A first refractive index film formed on the semiconductor substrate and having a recess for each region on the photoelectric conversion portion, and a refractive index higher than the first refractive index partially embedded in the recess of the first refractive index film The plurality of pixels include a first pixel in the central area of the imaging area and a second pixel in the peripheral area of the imaging area. The second pixel The upper surface of the second refractive index film is inclined so that the end portion on the first pixel side is lower than the end portion on the opposite side to the first pixel side.

  Moreover, the manufacturing method of the solid-state imaging device according to the present invention includes a plurality of pixels including, in an imaging area, a first pixel in a central region of the imaging area and a second pixel in a peripheral region of the imaging area. Is a method of manufacturing a solid-state imaging device in which a photoelectric conversion unit is formed for each pixel on a semiconductor substrate, and a step of forming a recess for each region on the photoelectric conversion unit on the semiconductor substrate. A step of forming the first refractive index film, and a part of the concave portion of the first refractive index film is embedded, and the upper surface of the second refractive index film in the second pixel is the first pixel side end portion of the first refractive index film. Forming a second refractive index film having a refractive index higher than the first refractive index so as to incline so as to be lower than the end opposite to the pixel side.

  In the solid-state imaging device according to the present invention, in the pixel in the peripheral region of the imaging area, the upper surface of the core layer, which is the second refractive index film, is opposite to the pixel side in the central region. It forms so that it may become lower than the edge part of the side. Note that the “height of the end” refers to the height from the upper surface of the semiconductor substrate.

  With this configuration, in the pixels in the peripheral region, the light passing through the microlens has an incident angle of light, which is an angle formed by a direction perpendicular to the upper surface of the core layer and an incident direction of the light, and the upper surface of the core layer is applied to the semiconductor substrate. It can be made smaller than when parallel to each other. Therefore, reflection of light on the upper surface of the core layer can be suppressed as compared with the conventional case. That is, even in the pixels in the peripheral region, light is not easily reflected on the upper surface of the core layer, and a decrease in sensitivity in the pixels in the peripheral region of the solid-state imaging device can be suppressed.

It is a top view of the solid-state imaging device concerning Embodiment 1 of the present invention. It is an enlarged view of the solid-state imaging device shown in FIG. It is sectional drawing in the pixel in the peripheral region of the solid-state imaging device shown in FIG. It is sectional drawing in the pixel in the center area | region of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the solid-state imaging device shown in FIG. It is process sectional drawing which shows typically a part of manufacturing process of the solid-state imaging device shown in FIG. It is a schematic diagram for demonstrating the solid-state imaging device shown in FIG. It is sectional drawing of the solid-state imaging device which concerns on Embodiment 2 of this invention. It is sectional drawing of the solid-state imaging device which concerns on Embodiment 3 of this invention. It is sectional drawing in alignment with the horizontal transfer direction of the conventional solid-state imaging device. It is sectional drawing which follows the vertical transfer direction of the conventional solid-state imaging device.

[Embodiment 1]
1. Overall Configuration of Solid-State Imaging Device 100 FIG. 1 is a plan view of solid-state imaging device 100 according to Embodiment 1. FIG.

  In the solid-state imaging device 100, a plurality of pixels are two-dimensionally arranged in the imaging area 110. In the imaging area 110, light enters from the vertical direction in the central region 120, and light enters from the oblique direction in the peripheral region. A pixel in the central region 120 is a central pixel 150 and a pixel in the peripheral region 130 is a peripheral pixel 140. Hereinafter, the peripheral pixel 140 will be described by taking as an example a pixel located at the same position as the central region 120 in the vertical transfer direction and positioned at the peripheral edge of the imaging area 110 in the horizontal transfer direction.

FIG. 2 is an enlarged view around the peripheral pixel 140 of the solid-state imaging device 100 shown in FIG. In the solid-state imaging device 100, a square photodiode 18 as a photoelectric conversion unit is formed for each pixel. The solid-state imaging device 100 includes a vertical transfer register 22 formed between photodiodes 18 adjacent in the horizontal direction, a vertical transfer electrode 32 formed on the vertical transfer register 22, and a photodiode 18 on the vertical transfer register 24. A connection electrode 36 having an opening is provided so as to be exposed. The vertical transfer electrode 32 and the connection electrode 36 are connected via a contact 34.
2. Configuration in Peripheral Region 130 of Solid-State Imaging Device 100 FIG. 3 is a cross-sectional view taken along line AA shown in FIG. 2, and the central pixel 150 shown in FIG.

  The solid-state imaging device 100 is stacked so as to cover the semiconductor substrate 11 including the n region 10 and the p well region 12, the photodiode 18 and the vertical transfer register 24 formed in the p well region 12, and the p well region 12. The insulating film 30, the electrode 32 formed on the insulating film 30, the cladding layer 40 that is the first refractive index material film formed on the electrode 32, and the refractive index of the cladding layer formed on the cladding layer 40 And a waveguide 44 including a core layer 42 which is a second refractive index material film having a high refractive index.

The photodiode 18 includes a lower n ⁺ -type diffusion layer 14 and an upper p ⁺ -type hole accumulation layer 16. An antireflection film 31 is formed on the insulating film 30 covering the upper surface of the photodiode 18. The insulating film 30 is made of, for example, a silicon oxide film, and the antireflection film 31 is made of, for example, a silicon nitride film. Note that the refractive index of the antireflection film 31 is larger than the refractive index of the semiconductor substrate 11 and smaller than the refractive index of the cladding layer 40.

  A vertical transfer register 24 is formed on one side of the photodiode 18 via a read gate 28. A p-type layer 26 as a channel stop region is formed on the other side of the photodiode 18. A vertical transfer register 24 is formed of a lower p-type layer 20 and an upper n-type transfer channel 22. Further, an electrode 32 made of, for example, a polysilicon film having the functions of a charge readout and charge transfer electrode is formed on the vertical transfer register 24 and the readout gate 28 via an insulating film 30. Further, a connection electrode 36 that also serves as a light shielding film is formed through the insulating film 33 so as to cover the electrode 32. The connection electrode 36 and the electrode 32 are connected by a contact 34.

  A cladding layer 40 having a recess 40a is formed in each region on the photodiode 18 so as to cover the antireflection film 31 and the connection electrode 36, and a core layer 42 partially embedded in the recess 40a of the cladding layer 40 is formed. It is formed.

A passivation film 60 made of, for example, silicon nitride (SiN or SiON) is formed on the waveguide 44 made of the cladding layer 40 and the core layer 42, and further, for example, a planarization film made of an organic coating film such as an acrylic resin A laminated structure is formed by 62, the color filter 64, and the microlens 66. The layout positions of the waveguide 44, the color filter 64, and the microlens 66 may be shifted according to the camera lens, even if the layout centers coincide.
3. Detailed Description of Waveguide 44 in Peripheral Pixel 140 in Peripheral Region 130 The upper surface 42a of the core layer 42 of the waveguide 44 has a quadrangular shape in plan view.

  In addition, in the cross section along the horizontal transfer direction of the solid-state imaging device 100, the waveguide so that oblique incident light with respect to the parallel surface of the upper surface of the semiconductor substrate 11 is incident on the upper surface 42 a of the core layer 42 of the waveguide 44 at a small incident angle. The upper surface 42 a of the core layer 42 at 44 is formed so as to be inclined such that the end portion 42 c on the central pixel 150 side is lower than the end portion 42 d on the opposite side to the central pixel 150. The end 42c on the central pixel 150 side in the solid-state imaging device 100 is a straight line connecting the central point of the peripheral pixel 140 and the central point of the central pixel 150 and the upper surface 42a of the core layer 42 when the imaging area 110 is viewed in plan. Of the two intersection points with the contour line (in this embodiment, a quadrangular shape), the point is close to the central pixel 150. The end 42d opposite to the central pixel 150 is a point far from the central pixel 150 among the intersections. “Height of the end” refers to the height from the upper surface of the semiconductor substrate 11. In the peripheral pixel 140, when viewed from a cross section along the vertical transfer direction, the light appears to be incident substantially vertically, and when viewed from the horizontal transfer direction cross section, the light appears to be incident from an oblique direction. Therefore, the upper surface 42a of the core layer 42 of the waveguide 44 is formed so as to be inclined only in the cross section along the horizontal transfer direction.

  The angle of inclination of the upper surface 42a of the core layer 42 with respect to the parallel surface of the semiconductor substrate 11 is greater than 0 ° and 30 ° or less. With this configuration, the upper surface 42a of the core layer 42 is substantially the same with respect to oblique light at F values of 1-12. The vertical direction. Note that the inclination angle of the upper surface 42a of the core layer 42 differs for each camera lens.

  Further, due to the inclination of the upper surface 42a of the core layer 42, for example, when the pixel size is 1.0 μm at the end of the core layer 42 on the central pixel 150 side and the end opposite to the central pixel 150 side, A step of 300 nm is formed. Further, the diameter or one side length of the upper surface 42a of the core layer 42 is formed to be 400 to 800 nm.

  The cladding layer 40 is formed of, for example, a silicon oxide film, and the core layer 42 is formed of, for example, a silicon nitride film, a silicon oxynitride film, or the like. When the refractive index n1 of the core layer 42 is the refractive index n2 of the cladding layer 40, n1> n2 is satisfied, such as n1 = 2.00 and n2 = 1.45. When light incident on the inside from the upper surface of the core layer 42 reaches the interface 42b between the core layer 42 and the cladding layer 40, it is difficult to enter the cladding layer 40 made of a material having a refractive index lower than that of the core layer 42. Light is reflected at the interface 42b. Therefore, the light incident from above in the stacking direction is guided to the lower photodiode 18 by the waveguide 44.

The specific pixel 140 has been described above as an example, but any pixel existing in the peripheral region 130 is the same. That is, the end 42c on the central pixel 150 side of the upper surface 42a of the core layer 42 is formed on a plane that is inclined so as to be lower than the end 42d on the opposite side to the central pixel 150.
4). Configuration in Central Region 120 of Solid-State Imaging Device 100 FIG. 4 is a cross-sectional view along the horizontal transfer direction of pixels in the central region 120 shown in FIG. When viewed from a cross section along the vertical transfer direction of the solid-state imaging device 100 in the central region 120, light is incident on the upper surface of the core layer 42 from a substantially vertical direction, so that the upper surface 42a of the core layer 42 of the waveguide 44 is the semiconductor substrate. 11 so as to be parallel to 11.
5. Method for Producing Waveguide 44 A method for producing the solid-state imaging device 100 according to Embodiment 1 of the present invention will be described with reference to FIGS. 5 to 7 are cross-sectional views along the horizontal transfer direction of the solid-state imaging device 100 shown in FIG.

  As shown in FIG. 5, an electrode 32, a connection electrode 36, and a cladding layer 40 covering them are formed on the semiconductor well layer 12 in which the photodiode 18 and the vertical transfer register 24 are formed. After depositing a core layer material 42e on the cladding layer 40, the resist film 50 is used as an etching mask.

  The resist film 50 is formed by lithography to have an opening 50a and an inclined upper surface 50b. In this lithography technique, for example, a gray scale mask 52 is applied. The gray scale mask 52 includes a quartz glass 52a and a chromium layer 52b formed on the quartz glass 52a. An opening having a minute size is arranged in the chromium layer 52b. By changing the aperture density, the transmittance of the chrome layer 52b changes, so that the resist film 50 having the inclined upper surface 50b can be formed. Note that the transmittance of the gray scale mask 52 is smaller than that corresponding to the portion where the height of the inclined upper surface 50b of the resist film 50 is increased.

As shown in FIG. 6, the resist film 50 is etched. In the portion where the resist film 50 does not exist, the core layer material 42e is etched.
Through the manufacturing process shown in FIG. 6, as shown in FIG. 7, a cladding layer 40 having a recess 40a in the region on the photodiode 18, and a core layer 42 partially embedded in the recess 40a of the cladding layer 40, A waveguide 44 is formed. Specifically, the etching is performed by dry etching, and the upper surface of the core layer 42 is inclined by transferring the resist film 50. Thereafter, the resist film 50 remaining in other regions is removed.
6). Driving of Solid-State Imaging Device 100 FIG. 8A is a schematic diagram of a module 1 using the solid-state imaging device 100. FIG. The module 1 may be a digital camera, for example.

Light that has entered the microlens 66 through the camera lens 400 passes through the waveguide 44 and enters the photodiode 18 that is a photoelectric conversion unit. Photoelectric conversion is performed by the photodiode 18 to generate charges corresponding to incident light. The generated charge moves to the vertical transfer register 24 via the read gate 28. Thereafter, the charge moves from the vertical transfer register 24 to the horizontal transfer register and is taken out to the outside.
7). Design Method of Waveguide 44 When a gray scale mask is used in the imaging area 110, the tilt direction of the core layer 42 can be set in an arbitrary area as shown in FIG. 8B. Area 5 is in the central area 120 of the imaging area 110 and the central pixel 150 exists, and areas other than area 5 are in the peripheral area 130 of the imaging area 110 and the peripheral pixels 140 exist. Note that the region where the core layer 42 of the waveguide 44 except the area 5 where the center point of the imaging area 110 is located is 5 to 20% of the entire imaging area 110. The inclination angles of the nine areas into which the imaging regions are divided are designed to be constant so that the end portion 42c on the central pixel 150 side is lower than the end portion 42d on the opposite side to the central pixel 150 in each area. .

  The cross-sectional structure shown in FIG. 3 is that of a pixel in area 2. In addition, in the pixels located at the corners such as areas 1, 3, 7, and 9, not only when viewed from the cross section along the horizontal transfer direction, but also when viewed from the cross section along the vertical transfer direction, The upper surface 42 a of the core layer 42 is formed as an inclined surface in which the end on the central pixel 150 side is lower than the end on the opposite side to the central pixel 150.

Further, the inclination angle of the upper surface 42 a of the waveguide 44 core layer 42 in the areas 4 and 6 is smaller than the inclination of the upper surface 42 a of the waveguide 44 core layer 42 in the areas 2 and 8. This is because the angle of incidence of oblique light becomes larger at a position farther from the center point of the imaging area 110, and accordingly, the tilt is adjusted so that the tilt becomes smaller when the distance from the center point of the imaging area 110 is larger. Because it is necessary to do.
8). Effect In this configuration, in the pixel in the peripheral region 130 where light is incident from an oblique direction, the upper surface 42a of the core layer 42 of the waveguide 44 has an end on the side of the central pixel 150 on the side opposite to the side of the central pixel 150. It is inclined to be lower than the part. Therefore, the normal line of the upper surface 42a of the core layer 42 faces the vicinity of the center point of the imaging area 110, and the incident angle of light on the upper surface 42a of the core layer 42 becomes small. That is, even in the pixels in the peripheral region 130, light is not easily reflected by the upper surface 42 a of the core layer 42 of the waveguide 44. Therefore, vignetting of light in the peripheral region 130 of the imaging area 110 is reduced, and a decrease in sensitivity in the peripheral region 130 of the imaging area 110 of the solid-state imaging device 100 can be suppressed.
[Embodiment 2]
1. Configuration FIG. 9 is a cross-sectional view taken along the horizontal transfer direction of peripheral pixels 140 in the peripheral region 130 of the solid-state imaging device 200 according to Embodiment 2 of the present invention. Since the configuration other than the following is the same as that of the solid-state imaging device 100, the description thereof is omitted.

The solid-state imaging device 200 includes a waveguide 244 composed of a clad layer 240 and a core layer 242, a passivation film 260 formed on the waveguide 244, a color filter 264 formed on the passivation film 260, and the color filter 264. A formed microlens 266 is provided. In all the pixels, the color filter 264 is formed on the convex portion of the clad layer 240 on which the passivation film 260 is formed and on the core layer 242, and the upper surface of the color filter 264 and the n region 10 are parallel to each other. In the peripheral pixel 140 in the peripheral region 130, the lower surface of the color filter 264 and the upper surface 242a of the corresponding core layer 242 are parallel.
2. Effect In this configuration, the color filter 264 also functions as a planarizing film. Therefore, since there is no planarization film 62 under the color filter 64 in the first embodiment, it is possible to manufacture a solid-state imaging device with fewer manufacturing steps. Further, as compared with the first embodiment, a low-profile structure in which the position of the micro lens 266 is lowered can be realized, and the distance between the camera lens 400 and the solid-state imaging device 200 can be reduced. Furthermore, since the number of interfaces in the solid-state imaging device 200 is reduced and light absorption at the interfaces is suppressed, the sensitivity of the solid-state imaging device 200 is improved.
[Embodiment 3]
1. Configuration FIG. 10 is a cross-sectional view along the horizontal transfer direction of the peripheral pixels 140 in the peripheral region 130 of the solid-state imaging device 300 according to Embodiment 3 of the present invention. Since it is the same as that of the solid-state imaging device 100, description thereof is omitted.

The solid-state imaging device 300 includes a waveguide 344 composed of a cladding layer 340 and a core layer 342, a passivation film 360 formed on the waveguide 344, a color filter 364 formed on the passivation film 360 with a uniform thickness, and A planarization film 365 formed on the color filter 364 is provided. In all pixels, the color filter 364 is formed on the convex portion of the cladding layer 340 on which the passivation film 360 is formed and the core layer 342. In addition, the upper surface 364a of the color filter 364 in the peripheral pixel 140 in the peripheral region 130 where light enters from an oblique direction is inclined such that the end on the central pixel 150 side is lower than the end on the opposite side to the central pixel 150 side. is doing.
2. Effect In the present embodiment, compared to the first embodiment, a low-profile structure in which the position of the microlens 366 is lowered can be realized, and the distance between the camera lens 400 and the solid-state imaging device 300 can be reduced. . Further, since the thickness of the color filter 364 can be made uniform, light absorption by the color filter 364 can be reduced and the sensitivity of the solid-state imaging device 300 can be improved as compared with the second embodiment.
[Modification]
1. The inclination of the upper surface of the core layer The inclination of the upper surface of the core layer is divided into nine areas as shown in the embodiments, etc., and may be constant for each area. A configuration may be employed such that the area closer to the imaging area center point has a gentler inclination. Further, in the embodiment and the like, in the region located at the corner of the imaging area, the structure in which the upper surface of the core layer is inclined when viewed from a cross section along the vertical transfer direction or when viewed from a cross section along the horizontal transfer direction. However, when areas 1, 2, 3, 7, 8, and 9 in FIG. 8B are viewed from a section along the horizontal transfer direction, areas 4 and 6 are viewed from a section along the vertical transfer direction. In addition, a configuration in which the upper surface of the core layer is inclined may be employed.
2. When the upper surface of the core layer has a curved shape, the shape of the upper surface of the core layer may be an inclined flat surface as shown in the embodiment or the like, or an inclined curved surface. As the shape of the curved surface, for example, there is a curved surface shape convex upward or downward. In addition, when considering the cross section of the curved surface so as to pass through the center point of the imaging area, the curved surface is preferably a curved surface in which the slope of the tangent to the upper curve of the cross section is always positive or always negative. It is preferable that the end of the central region 120 opposite to the pixel side is higher in shape than the pixel side point in the central region 120.
3. Others In the embodiments and the like, a CCD type solid-state imaging device is used, but a MOS type solid-state imaging device may be used. In the embodiment and the like, the antireflection film formed for each photodiode may not be provided in the passivation film formed on the waveguide and the cladding layer. The shape of the upper surface of the core layer may be a quadrangular prism shape shown in the embodiment or the like, and may be, for example, a circular shape, a triangular shape, a pentagonal shape, or other polygonal shapes.

  In Embodiments 2 and 3, the color filter is formed directly on the waveguide on which the passivation film is formed. However, a planarizing film is formed between the passivation film and the color filter, and the lower surface of the color filter and the semiconductor are formed. You may take the structure which inclines with a board | substrate with arbitrary inclination.

  The configuration of the solid-state imaging device according to the present invention is not limited to the configuration of the solid-state imaging device according to the above-described embodiment, and various modifications and applications are possible within the scope of the effects of the present invention. is there. In addition, the process used in each step described above can be replaced with another equivalent process without departing from the technical idea. Moreover, it is also possible to change a process order and to change a material kind.

  The present invention can be used for a digital camera or the like, and is useful for realizing a solid-state imaging device in which deterioration of image quality is suppressed.

100, 200, 300, 900 Solid-state imaging device 11, 910 Semiconductor substrate 18, 918 Photo diode 22, 922 Vertical transfer register 32, 932 Electrode 40, 240, 340, 940 Clad layer 42, 242, 342, 942 Core layer 44, 244,344,944 Waveguide

Claims (10)

A solid-state imaging device in which a plurality of pixels are two-dimensionally arranged in an imaging area,
A semiconductor substrate on which a photoelectric conversion unit is formed for each pixel;
A first refractive index film formed on the semiconductor substrate and having a recess for each region on the photoelectric conversion unit;
A second refractive index film having a refractive index higher than the first refractive index, partially embedded in the recess of the first refractive index film,
The plurality of pixels include a first pixel in a central area of the imaging area and a second pixel in a peripheral area of the imaging area,
The upper surface of the second refractive index film in the second pixel is inclined so that the end on the first pixel side is lower than the end on the opposite side to the first pixel side. A solid-state imaging device. The solid-state imaging device according to claim 1, wherein an upper surface of the second refractive index film in the second pixel is planar. The upper surface of the second refractive index film in the second pixel is curved.
The shape of the curved surface is such that the end opposite to the first pixel side is higher than all the points located on the first pixel side than the end. The solid-state imaging device according to claim 1. A color filter is formed on the convex portion of the first refractive index film and the second refractive index film, corresponding to each of the photoelectric conversion portions,
The upper surface of the color filter and the semiconductor substrate are parallel,
4. The solid-state imaging device according to claim 1, wherein, in the second pixel, the lower surface of the color filter and the upper surface of the corresponding second refractive index film are parallel to each other. A color filter is formed on the convex portion of the first refractive index film and the second refractive index film, corresponding to each of the photoelectric conversion portions,
The upper surface of the color filter in the second pixel is inclined such that an end portion on the first pixel side is lower than an end portion on the opposite side to the first pixel side,
4. The solid-state imaging according to claim 1, wherein an upper surface of the color filter, a lower surface of the color filter, and an upper surface of the second refractive index film are all parallel in the second pixel. apparatus. 6. The solid-state imaging device according to claim 1, wherein an inclination angle of the upper surface of the second refractive index material film is greater than 0 ° and 30 ° or less with respect to the upper surface of the semiconductor substrate. 7. The solid-state imaging device according to claim 1, wherein an upper surface of the second refractive index film in the first pixel is parallel to an upper surface of the semiconductor substrate. The solid-state imaging device according to any one of claims 1 to 7, wherein an antireflection film is formed in each of the photoelectric conversion units in the first refractive index material film. An imaging module comprising: the solid-state imaging device according to claim 1; and a lens. A method of manufacturing a solid-state imaging device in which a plurality of pixels including a first pixel in a central area of the imaging area and a second pixel in a peripheral area of the imaging area are two-dimensionally arranged in the imaging area There,
Forming a photoelectric conversion unit for each pixel on a semiconductor substrate;
Forming a first refractive index film having a recess for each region on the photoelectric conversion unit on the semiconductor substrate;
A part of the concave portion of the first refractive index film is embedded, and the upper surface of the second refractive index film in the second pixel is opposite to the first pixel side at the end on the first pixel side. Forming a second refractive index film having a refractive index higher than the first refractive index so as to incline so as to be lower than the end on the side. A method for manufacturing a solid-state imaging device, comprising:

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