camera device

Abstract

The subject of this disclosure is to provide a camera device that can further suppress color mixing between pixels. The imaging device disclosed herein includes: a semiconductor substrate, on which a photoelectric conversion unit is disposed in each of the two-dimensionally arranged pixels; a color filter disposed on the semiconductor substrate for each of the pixels; an intermediate layer disposed between the semiconductor substrate and the color filter; and a low-refractive-index region disposed between the pixels, separating at least the color filter and the intermediate layer for each of the pixels, and having a refractive index lower than that of the color filter.

Description

[Technical Field]

[0001] This disclosure relates to a camera device. [Previous Technology]

[0002] As imaging devices used in digital cameras or video cameras, CCD (Charge Coupled Device) image sensors or CMOS (Complementary MOS (Metal Oxide Semiconductor) image sensors are known.

[0003] These image sensors are provided as back-illuminated imaging devices, for example, in which a photoelectric conversion unit receives light incident from the back side of a semiconductor substrate without a wiring layer (see, for example, Patent Document 1). [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2012-209542 [Summary of the Invention]

[0005] [The problem the invention aims to solve]

[0006] In this kind of camera device, in order to further improve the image quality of the captured image, it is sought to suppress color mixing between pixels.

[0007] In view of the above, it is desirable to provide a novel and improved imaging device that can further suppress inter-pixel color mixing. [Technical Means for Solving the Problem]

[0008] According to this disclosure, an imaging device is provided, comprising: a semiconductor substrate, wherein an optical conversion unit is disposed on each of the two-dimensionally arranged pixels; a color filter disposed on the semiconductor substrate for each of the pixels; an intermediate layer disposed between the semiconductor substrate and the color filter; and a low refractive index region disposed between the pixels, wherein at least the color filter and the intermediate layer are separated for each of the pixels, and the refractive index is lower than that of the color filter.

[0009] According to this disclosure, light traveling on adjacent pixels can be reflected at the interface between the color filter and the low-refractive region, and at the interface between the intermediate layer and the low-refractive region.

Implementation Method

[0011] Hereinafter, a preferred embodiment of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in this specification and drawings, repeated descriptions are omitted by using the same symbols to denote constituent elements that substantially have the same functional configuration.

[0012] Furthermore, the explanation shall proceed in the following order: 1. Overall structure of the imaging device; 2. First embodiment; 2.1. Structure of the pixel unit; 2.2. Variation example; 3. Second embodiment; 3.1. Structure of the pixel unit; 3.2. Variation example; 4. Structure of the electronic device; 5. Application example.

[0013] <1. Overall Structure of the Camera Device> First, referring to FIG1, the overall structure of the camera device applying the technology disclosed herein will be described. FIG1 is a schematic diagram showing the overall structure of the camera device 100 applying the technology disclosed herein.

[0014] As shown in FIG1, the camera device 100 includes a pixel section 13 having a plurality of pixels 12 forming a semiconductor substrate, a vertical driving circuit 14, a horizontal signal processing circuit 15, a horizontal driving circuit 16, an output circuit 17, and a control circuit 18.

[0015] The pixel unit 13 includes a plurality of pixels 12 arranged in a two-dimensional pattern. For example, the pixel unit 13 may include the following: an effective pixel region, which includes a pixel that amplifies the signal charge that performs photoelectric conversion on the incident light and reads it out to the line signal processing circuit 15; and a black reference pixel region (not shown), which includes a pixel that outputs an optical black as a reference for the black level. The black reference pixel region is formed, for example, on the periphery of the effective pixel region.

[0016] Pixel 12 is composed of, for example, a photoelectric conversion element, i.e., a photodiode (not shown), and a pixel circuit (not shown) including a transmission transistor, a reset transistor, a selection transistor, and an amplification transistor. Alternatively, the pixel circuit may not include a selection transistor. The signal charge after photoelectric conversion by the photodiode is converted into a pixel signal by the pixel circuit.

[0017] Furthermore, pixels 12 can share a pixel structure. In the shared pixel structure, the plurality of pixels 12 are composed of a plurality of photodiodes, a plurality of transmission transistors, a shared floating diffusion region, and a shared reset transistor, selection transistor, and amplification transistor. That is, in the shared pixel structure, the photodiodes and transmission transistors included in the plurality of pixels 12 share the reset transistor, selection transistor, and amplification transistor.

[0018] The control circuit 18 generates clock signals and control signals based on the vertical synchronization signal, the horizontal synchronization signal, and the main clock, which serve as the reference for the operation of the vertical drive circuit 14, the horizontal signal processing circuit 15, and the horizontal drive circuit 16. The control circuit 18 uses the clock signals and control signals to control the vertical drive circuit 14, the horizontal signal processing circuit 15, and the horizontal drive circuit 16.

[0019] The vertical drive circuit 14 is composed of, for example, a shift register. The vertical drive circuit 14 sequentially selects the scan pixels 12 in the vertical direction in column units. The vertical drive circuit 14 supplies the pixel signal generated according to the amount of light received in the pixel 12 to the row signal processing circuit 15 via the vertical signal line 19.

[0020] A horizontal signal processing circuit 15 is configured in, for example, each row of pixels 12. Based on the signal from the black reference pixel region, the horizontal signal processing circuit 15 performs signal processing such as noise removal and signal amplification on the pixel signals output from one column of pixels 12 in each pixel row. A horizontal selection switch (not shown) is provided between the output segment of the horizontal signal processing circuit 15 and the horizontal signal line 20.

[0021] The horizontal drive circuit 16 is composed of, for example, a shift register. The horizontal drive circuit 16 sequentially selects each of the line signal processing circuits 15 by sequentially outputting horizontal scan pulses, and each of the line signal processing circuits 15 outputs a pixel signal to the horizontal signal line 20.

[0022] The output circuit 17 processes the pixel signals sequentially supplied by the self-signal processing circuit 15 via the horizontal signal line 20, and outputs the processed pixel signals to the outside.

[0023] <2. First Embodiment> (2.1. Pixel Unit Structure) Next, referring to FIG2, the cross-sectional structure of the pixel unit 13 of the first embodiment disclosed herein will be described. FIG2 is a longitudinal sectional view showing the cross-sectional structure of the pixel unit 13.

[0024] As shown in FIG2, the pixel unit 13 includes a semiconductor substrate 110, an intermediate layer 120, a color filter 130, an insulating layer 141, a crystal lens 151, and an anti-reflective film 152.

[0025] The semiconductor substrate 110 is, for example, a silicon (Si) substrate with a thickness of 1 μm to 6 μm. On the semiconductor substrate 110, a photoelectric conversion unit 111 is provided for each pixel 12 to generate a signal charge corresponding to the amount of incident light received. The photoelectric conversion unit 111 is, for example, a photodiode, constructed by providing a second conductivity type (e.g., N-type) semiconductor region within a first conductivity type (e.g., P-type) semiconductor region for each pixel 12.

[0026] Furthermore, the photoelectric conversion units 111 provided for each pixel 12 are electrically separated from each other by pixel separation walls 112 made of insulating material. The pixel separation walls 112 may be provided by extending an insulating material such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON) in the thickness direction of the semiconductor substrate 110.

[0027] Furthermore, on the side of the semiconductor substrate 110 opposite to the side where the intermediate layer 120 is disposed (also called the back side), a circuit layer is provided that includes a pixel circuit that converts the signal charge after photoelectric conversion by the photoelectric conversion unit 111 into a pixel signal. That is, the imaging device 100 of this embodiment is a back-illuminated type imaging device that receives light incident from the back side of the semiconductor substrate 110.

[0028] The intermediate layer 120 is a functional layer disposed on the semiconductor substrate 110 with an insulating material. The intermediate layer 120 is disposed on the semiconductor substrate 110 separately by the low refractive index region 140 described later for each pixel 12.

[0029] The intermediate layer 120 may include a layer with a negative fixed charge. Specifically, the intermediate layer 120 may include a layer made of a high dielectric material with a negative fixed charge, such as hafnium oxide (HfO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), tantalum oxide (Ta2O5), titanium oxide (TiO2), magnesium oxide (MgO), yttrium oxide (Y2O3), or lanthanide oxides. In this case, the intermediate layer 120 can form a region where positive charges accumulate at the interface with the semiconductor substrate 110 due to the negative fixed charge, thereby suppressing the generation of dark current.

[0030] Furthermore, the intermediate layer 120 may include a layer with anti-reflective properties. Specifically, the intermediate layer 120 may include a dielectric layer with a refractive index lower than that of the semiconductor substrate 110. In this case, the intermediate layer 120 can suppress light reflection at the interface with the semiconductor substrate 110, thereby improving the efficiency of incident light to the photoelectric conversion unit 111.

[0031] For example, the intermediate layer 120 can be provided by sequentially depositing aluminum oxide (Al2O3), tantalum oxide (Ta2O5), and silicon oxide (SiO2) from the semiconductor substrate 110 side.

[0032] Color filters 130 are disposed on the intermediate layer 120 for each pixel 12, allowing selective transmission of light in the wavelength band corresponding to each pixel 12 (e.g., red light (R), green light (G), and blue light (B)). Color filters 130 can be arranged in a specific RGB arrangement, such as a Bayer arrangement. Color filters 130 are separately disposed on the semiconductor substrate 110 for each pixel 12 by low-refractive-index regions 140, described later.

[0033] The color filter 130 can be provided by adding pigments or dyes to a transparent resin that allows visible light to pass through, for example. Also, the color filter 130 can be a transparent filter made of a transparent resin that allows visible light to pass through, or an ND (Neutral Density) filter made by adding carbon black to a transparent resin.

[0034] In the pixel section 13 of the camera device 100 of this embodiment, the color filter 130 and the intermediate layer 120 are separated by a low refractive region 140 extending in the thickness direction of the semiconductor substrate 110 for each pixel 12.

[0035] The low-refractive-index region 140 is a region with a refractive index lower than that of the color filter 130. For example, the low-refractive-index region 140 may be a region with a refractive index of 1.0 or higher and 1.35 or lower. By being disposed between the color filters 130 disposed for each pixel 12 and between the intermediate layers 120 disposed for each pixel 12, the low-refractive-index region 140 enables the color filters 130 and the intermediate layers 120 to function as waveguides consisting of a low-refractive-index material sandwiching a high-refractive-index material. Accordingly, since the low-refractive-index region 140 can cause light traveling at adjacent pixels 12 to be reflected at the interface with the color filter 130 and the interface with the intermediate layer 120, the efficiency of incident light to the photoelectric conversion unit 111 can be improved.

[0036] The low-refractive-index region 140 can be made of any material as long as its refractive index is lower than that of the color filter 130. For example, the low-refractive-index region 140 can be voids, or it can be made of inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON), or resin-based materials such as styrene-based resins, acrylic resins, styrene-acrylic copolymer resins, or siloxane resins. Furthermore, the low-refractive-index region 140 can also be made of so-called low-k materials such as SiOF, SiOC, or porous silicon dioxide.

[0037] The insulating layer 141 is provided on the color filter 130 with an insulating material. For example, the insulating layer 141 is provided by forming a film of silicon oxide (SiO2) on the color filter 130. Accordingly, the insulating layer 141, which is formed on the color filter 130 separated by each pixel 12 with a high coverage ratio, does not embed in the low refractive region 140 between the color filters 130, but directly seals the upper end as a gap, so the low refractive region 140 can be formed as a gap.

[0038] Wherein, at least a portion of the inner wall of the void, i.e., the low-refractive region 140, can be covered by insulating material that enters during the film formation of the insulating layer 141. Here, the cross-sectional shape of the void, i.e., the low-refractive region 140, will be described with reference to FIG3. FIG3 is a longitudinal sectional view showing the variation of the cross-sectional shape of the void constituting the low-refractive region 140.

[0039] As shown in Figure 3, the cross-sectional shape of the gap constituting the low refractive region 140 can vary depending on the coating condition of the insulating material that enters the inner side of the low refractive region 140 during the film formation of the insulating layer 141 on the inner wall of the low refractive region 140.

[0040] For example, the cross-sectional shape of the gap constituting the low-refractive region 140 can be a spindle shape, as shown in FIG3(A), with the upper and lower ends being thinner than the central portion. Also, the cross-sectional shape of the gap constituting the low-refractive region 140 can be a spindle shape, as shown in FIG3(B), with the upper end being thinner than the central portion and the lower end being thicker than the central portion. Furthermore, the cross-sectional shape of the gap constituting the low-refractive region 140 can also be a spindle shape, as shown in FIG3(C), with the upper end being thicker than the central portion and the lower end being thinner than the central portion. Moreover, the cross-sectional shape of the gap constituting the low-refractive region 140 can also be a dumbbell shape, as shown in FIG3(D), with the upper end being thicker than the central portion and the lower end being thicker than the central portion.

[0041] A crystal carrier lens 151 is disposed on the insulating layer 141 for each pixel 12. The crystal carrier lens 151 may be formed of a resin-based material such as styrene-based resin, acrylic resin, styrene-acrylic copolymer resin, or silicone resin. The crystal carrier lens 151 can concentrate the light incident on the pixel 12, and the photoelectric conversion unit 111 can make the light incident on the pixel 12 efficiently.

[0042] Furthermore, an antireflective film 152 may be formed on the surface of the crystal lens 151. The antireflective film 152 is, for example, composed of a dielectric multilayer film. The antireflective film 152 can suppress the reflection of light incident on the crystal lens 151.

[0043] Next, referring to FIGS. 4A to 4C, the planar configuration of the pixel unit 13 of the imaging device 100 of this embodiment will be described. FIGS. 4A to 4C are top views showing an example of the planar configuration of the pixel unit 13.

[0044] As shown in FIG4A, the low-refractive-index region 140 can surround each of the two-dimensionally arranged pixels 12 and cover the entire perimeter of the pixels 12. In this case, the low-refractive-index region 140 can more reliably reflect the light that passes through the color filter 130 and the intermediate layer 120 and travels with the adjacent pixels 12, thus more reliably suppressing color mixing with the adjacent pixels 12.

[0045] As shown in Figures 4B and 4C, the low-refractive-index region 140 can be disposed in the region corresponding to the edge of each of the two-dimensionally arranged pixels 12. Even in this case, the low-refractive-index region 140 can suppress color mixing with the adjacent pixels 12 because it can reflect most of the light that passes through the color filter 130 and the intermediate layer 120 and travels with the adjacent pixels 12.

[0046] Furthermore, when the low-refractive region 140 is provided in the region corresponding to the edge of each of the pixels 12, the diagonal regions 12A of each pixel 12 are thicker than the spacing between the pixels 12 in the region corresponding to the edge of the pixel 12. Therefore, as shown in FIG4B, for the diagonal regions 12A, each of the pixels 12 is provided in a rectangular shape, thereby making the spacing between the pixels 12 approximately the same in both the diagonal regions 12A and the regions corresponding to the edge of the pixel 12. Accordingly, the imaging device 100 can simplify the process conditions of the manufacturing steps of the pixel section 13.

[0047] Furthermore, when the low-refractive-index region 140 is provided in the region corresponding to the edge of each of the pixels 12, as shown in FIG4C, the diagonal region 12A of each of the pixels 12 can be embedded with inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON) with a refractive index lower than that of the color filter 130, resin materials such as styrene-based resins, acrylic resins, styrene-acrylic copolymer resins, or siloxane resins, or so-called low-k materials such as SiOF, SiOC, or porous silicon dioxide. Accordingly, in the diagonal region 12A of each of the pixels 12, since the light traveling through the color filter 130 and the intermediate layer 120 to the adjacent pixels 12 can be reflected by the material with a refractive index lower than that of the color filter 130, color mixing with the adjacent pixels 12 can be suppressed more reliably.

[0048] (2.2. Variation Examples) Next, referring to Figures 5 to 29C, the first to 23rd variations of the pixel unit 13 of the camera device 100 in this embodiment will be described.

[0049] (First Variation) FIG5 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13A in the first variation. As shown in FIG5, the pixel portion 13A in the first variation differs from the pixel portion 13 shown in FIG2 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 into the interior of the pixel separation wall 112.

[0050] Specifically, the low-refractive-index region 140 extends from the color filters 130 to the interior of the pixel separation wall 112 near the front side of the semiconductor substrate 110. In the first variation, the pixel portion 13A can suppress light leakage between the photoelectric conversion sections 111 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13A in the first variation can further suppress color mixing between adjacent pixels 12.

[0051] (Second Variation) FIG6 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13B in the second variation. As shown in FIG6, the pixel portion 13B in the second variation differs from the pixel portion 13A shown in FIG5 in that the low refractive region 140 extends from the points between the color filters 130 and between the intermediate layers 120 to the crystal lens 151.

[0052] Specifically, the low-refractive-index region 140 extends from between the color filters 130 to the interior of the pixel separation wall 112 near the front side of the semiconductor substrate 110, and extends to the side of the crystal lens 151, with the crystal lens 151 arranged in a manner that separates each pixel 12. In the second variation, the pixel portion 13B can suppress light leakage between the photoelectric conversion sections 111 of adjacent pixels 12 through the low-refractive-index region 140. Furthermore, in the second variation, the pixel portion 13B can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13B in the second variation can further suppress color mixing between adjacent pixels 12.

[0053] (Third Variation) FIG7 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13C in the third variation. As shown in FIG7, the pixel portion 13C in the third variation differs from the pixel portion 13 shown in FIG2 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 into the interior of the pixel separation wall 112.

[0054] Specifically, the low-refractive-index region 140 extends from the color filters 130 to the interior of the pixel separation wall 112, which is half of the semiconductor substrate 110. In the third variation, the pixel portion 13C can suppress light leakage between the photoelectric conversion sections 111 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13C in the third variation can further suppress color mixing between adjacent pixels 12.

[0055] (4th Variation) FIG8 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13D in the 4th Variation. As shown in FIG8, the pixel portion 13D in the 4th Variation differs from the pixel portion 13C shown in FIG7 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the side of the crystal lens 151.

[0056] Specifically, the low-refractive-index region 140 extends from between the color filters 130 into the interior of the pixel separation wall 112 of one half of the semiconductor substrate 110, and extends to the side of the crystal lens 151, with the crystal lens 151 arranged in a manner that separates each pixel 12. In the fourth variation, the pixel portion 13D can suppress light leakage between the photoelectric conversion sections 111 of adjacent pixels 12 through the low-refractive-index region 140. Furthermore, in the fourth variation, the pixel portion 13D can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13D in the fourth variation can further suppress color mixing between adjacent pixels 12.

[0057] (Fifth Variation) FIG9 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13E in the fifth variation. As shown in FIG9, the pixel portion 13E in the fifth variation differs from the pixel portion 13 shown in FIG2 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the side of the crystal lens 151.

[0058] Specifically, the low-refractive-index region 140 extends to the crystal lens 151 side, and the crystal lens 151 is arranged in such a way that each pixel 12 is separated. In the fifth variation, the pixel portion 13E can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 in the low-refractive-index region 140. Therefore, the pixel portion 13E of the fifth variation can further suppress color mixing between adjacent pixels 12.

[0059] (Sixth Variation) FIG10 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13F in the sixth variation. As shown in FIG10, the pixel portion 13F in the sixth variation differs from the pixel portion 13 shown in FIG2 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 into the interior of the pixel separation wall 112.

[0060] Specifically, the pixel separation wall 112 extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110. Furthermore, the low-refractive-index region 140 extends from between the color filters 130 into the interior of the pixel separation wall 112 in one half of the semiconductor substrate 110. In the sixth variation, the pixel portion 13F can suppress light leakage between the photoelectric conversion sections 111 of adjacent pixels 12 using the low-refractive-index region 140. Therefore, in the seventh variation, the pixel portion 13F can further suppress color mixing between adjacent pixels 12.

[0061] (Seventh Variation) FIG11 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13G in the seventh variation. As shown in FIG11, the pixel portion 13G in the seventh variation differs from the pixel portion 13F shown in FIG10 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the crystal lens 151 side.

[0062] Specifically, the low-refractive-index region 140 extends from the color filters 130 to the interior of the pixel separation wall 112 of one half of the semiconductor substrate 110, and extends to the side of the crystal lens 151, with the crystal lens 151 separated for each pixel 12. In the seventh variation, the pixel portion 13G can suppress light leakage between the photoelectric conversion sections 111 of adjacent pixels 12 through the low-refractive-index region 140. Furthermore, in the seventh variation, the pixel portion 13G can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13G in the seventh variation can further suppress color mixing between adjacent pixels 12.

[0063] (8th Variation) FIG12 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13H in the 8th Variation. As shown in FIG12, the pixel portion 13H in the 8th Variation differs from the pixel portion 13 shown in FIG2 in that the pixel separation wall 112 extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110.

[0064] Even in the eighth variation of the pixel section 13H, the pixel separation wall 112 can electrically separate the photoelectric conversion section 111 of adjacent pixels 12. Therefore, even in the eighth variation of the pixel section 13H, like the pixel section 13 shown in FIG2, color mixing between adjacent pixels 12 can be suppressed.

[0065] (9th Variation) FIG13 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13I in the 9th Variation. As shown in FIG13, the pixel portion 13I in the 9th Variation differs from the pixel portion 13H shown in FIG12 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the side of the crystal lens 151.

[0066] Specifically, the low-refractive-index region 140 extends to the crystal lens 151 side, and the crystal lens 151 is arranged in such a way that each pixel 12 is separated. In the ninth variation, the pixel portion 13I can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13I of the ninth variation can further suppress color mixing between adjacent pixels 12.

[0067] (10th Variation) FIG14 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 13J in the 10th Variation. As shown in FIG14, the difference between the pixel portion 13J in the 10th Variation and the pixel portion 13 shown in FIG2 is that a light-shielding portion 113 is provided inside the pixel separation wall 112.

[0068] The light-shielding portion 113 is provided embedded inside the pixel separation wall 112 on the side of the intermediate layer 120. For example, the light-shielding portion 113 may be made of a conductive material capable of blocking light, such as tungsten (W), aluminum (Al), copper (Cu), titanium nitride (TiN), or polysilicon (poly-Si). Alternatively, the light-shielding portion 113 may also be made of an organic resin material containing carbon black pigment or titanium black pigment. The light-shielding portion 113 can suppress color mixing between adjacent pixels 12 by blocking light leaking to adjacent pixels 12 through the photoelectric conversion portion 111 near the intermediate layer 120. Accordingly, the pixel portion 13J of the tenth variation can further suppress color mixing between adjacent pixels 12.

[0069] (11th Variation) FIG15 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13K in the 11th Variation. As shown in FIG15, the pixel portion 13K in the 11th Variation differs from the pixel portion 13J shown in FIG14 in that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the side of the crystal lens 151.

[0070] Specifically, the low-refractive-index region 140 extends to the crystal lens 151 side, and the crystal lens 151 is arranged in such a way that each pixel 12 is separated. In the 11th variation, the pixel portion 13K can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13K in the 11th variation can further suppress color mixing between adjacent pixels 12.

[0071] (12th Variation) FIG16 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13L in the 12th Variation. As shown in FIG16, the pixel portion 13L in the 12th Variation differs from the pixel portion 13J shown in FIG14 in that the pixel separation wall 112 extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110.

[0072] Even in the 12th variation of the pixel section 13L, the pixel separation wall 112 can electrically separate the photoelectric conversion section 111 of adjacent pixels 12. Therefore, even in the 12th variation of the pixel section 13L, like the pixel section 13J shown in FIG14, color mixing between adjacent pixels 12 can be suppressed.

[0073] (13th Variation) FIG17 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13M in the 13th Variation. As shown in FIG17, the difference between the pixel portion 13M in the 13th Variation and the pixel portion 13L shown in FIG16 is that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the side of the crystal lens 151.

[0074] Specifically, the low-refractive-index region 140 is provided in such a way that it extends to the crystal lens 151 side and separates the crystal lens 151 for each pixel 12. In the 13th variation, the pixel portion 13M can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13M in the 13th variation can further suppress color mixing between adjacent pixels 12.

[0075] (14th Variation) FIG18 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13N in the 14th Variation. As shown in FIG18, the difference between the pixel portion 13N in the 14th Variation and the pixel portion 13J shown in FIG14 is that the light-shielding portion 113 is provided to extend inside the pixel separation wall 112 and penetrate the semiconductor substrate 110.

[0076] In the 14th variation, the pixel portion 13N can cover the entire pixel separation wall 112 with the light shielding portion 113 to block the light leaking to the photoelectric conversion portion 111 of the adjacent pixel 12, thereby suppressing the color mixing between adjacent pixels 12.

[0077] (15th Variation) FIG19 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13O of the 15th Variation. As shown in FIG19, the difference between the pixel portion 13O of the 15th Variation and the pixel portion 13N shown in FIG18 is that the low refractive region 140 extends from between the color filters 130 and between the intermediate layers 120 to the side of the crystal lens 151.

[0078] Specifically, the low-refractive-index region 140 extends to the crystal lens 151 side, and the crystal lens 151 is arranged in such a way that each pixel 12 is separated. In the 15th variation, the pixel portion 13O can suppress light leakage between the crystal lenses 151 of adjacent pixels 12 through the low-refractive-index region 140. Therefore, the pixel portion 13O of the 15th variation can further suppress color mixing between adjacent pixels 12.

[0079] (16th Variation) FIG20 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 13P in the 16th Variation. As shown in FIG20, the difference between the pixel portion 13P in the 16th Variation and the pixel portion 13J shown in FIG14 is that the low refractive region 140 is not a gap, but is provided as a low refractive layer 142.

[0080] The low-refractive-index layer 142 is made of a material with a refractive index lower than that of the color filter 130, and is disposed between the color filters 130 disposed at each pixel 12 and between the intermediate layers 120 disposed at each pixel 12. The material with a refractive index lower than that of the color filter 130 is, for example, inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON); resin-based materials such as styrene-based resins, acrylic resins, styrene-acrylic copolymer resins, or siloxane resins; or low-k materials such as SiOF, SiOC, or porous silicon dioxide. The low-refractive-index layer 142 enables the color filter 130 and the intermediate layer 120 to function as waveguides consisting of a low-refractive-index material sandwiching a high-refractive-index material.

[0081] Accordingly, in the 16th variation, pixel portion 13P can reflect light traveling on adjacent pixels 12 at the interface between the low-refractive layer 142 and the color filter 130, and at the interface between the low-refractive layer 142 and the intermediate layer 120. Therefore, even in the 16th variation, pixel portion 13P, like pixel portion 13J shown in FIG14, can suppress color mixing between adjacent pixels 12.

[0082] (17th Variation) FIG21 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 13Q in the 17th Variation. As shown in FIG21, the pixel portion 13Q in the 17th Variation differs from the pixel portion 13J shown in FIG14 in that an anti-reflective layer 153 is provided between the insulating layer 141 and the crystal lens 151, and an anti-reflective intermediate layer 121 is provided instead of the intermediate layer 120.

[0083] The anti-reflection interlayer 121 and the anti-reflection layer 153 are made of, for example, a dielectric multilayer film. The anti-reflection interlayer 121 and the anti-reflection layer 153 can improve the efficiency of incident light on the photoelectric conversion unit 111 by suppressing the reflection of incident light at the interface between the layers present in the crystal lens 151 and the semiconductor substrate 110.

[0084] Furthermore, as long as the anti-reflective intermediate layer 121 and the anti-reflective layer 153 have anti-reflective function, they can be configured in a structure other than a dielectric multilayer film. For example, the anti-reflective intermediate layer 121 and the anti-reflective layer 153 can also be configured as layers with a moth-eye structure.

[0085] Accordingly, the pixel unit 13Q in the 17th variation can further improve the efficiency of the photoelectric conversion unit 111 in receiving incident light by further suppressing the reflection of incident light.

[0086] (18th Variation) FIG22 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 13R in the 18th Variation. As shown in FIG22, the difference between the pixel portion 13R in the 18th Variation and the pixel portion 13J shown in FIG14 is that an inorganic color filter 131 is provided instead of a color filter 130.

[0087] The inorganic color filter 131 is not a pigment or dye, but a filter that selectively transmits light of a specific wavelength band (e.g., red, green, and blue light) through the construction of dielectric multilayer films, photonic crystals, quantum dots, or metamaterials. Compared to pigments or dyes, the inorganic color filter 131 is less likely to fade due to ultraviolet light or heat. Therefore, even in more severe environments, the pixel portion 13R of the 18th variation can suppress color mixing between adjacent pixels 12, just like the pixel portion 13J shown in FIG14.

[0088] (19th Variation) FIG23 is a longitudinal sectional view showing the cross-sectional structure of the pixel section 13S in the 19th Variation. As shown in FIG23, the difference between the pixel section 13S in the 19th Variation and the pixel section 13J shown in FIG14 is that a low refractive index region 140A is provided in the portion of the pixel separation wall 112 where the light-shielding portion 113 is not provided.

[0089] The low-refractive-index region 140A is a region with a refractive index lower than that of the pixel separation wall 112. The low-refractive-index region 140A can be extended into the interior of the pixel separation wall 112 in the portion where the light-shielding part 113 is not provided, and reflect light leaking to the photoelectric conversion part 111 of the adjacent pixel 12. Like the low-refractive-index region 140, the low-refractive-index region 140A can be a void, or it can be made of inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON), resin materials such as styrene-based resin, acrylic resin, styrene-acrylic copolymer resin, or siloxane resin, or so-called low-k materials such as SiOF, SiOC, or porous silicon dioxide.

[0090] Accordingly, since the pixel portion 13S of the 19th variation can cover the entire pixel separation wall 112, it can block or reflect the light leaked to the photoelectric conversion portion 111 of the adjacent pixel 12, thereby suppressing the color mixing between adjacent pixels 12.

[0091] (20th Variation) Figure 24 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section 13T in the 20th Variation. As shown in Figure 24, the difference between the pixel section 13T in the 20th Variation and the pixel section 13J shown in Figure 14 is that the crystal lens 151 is not provided.

[0092] Even for this 20th variation of the pixel section 13T, the same as the pixel section 13J shown in FIG14, it can suppress color mixing between adjacent pixels 12.

[0093] (21st Variation) FIG25 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section 13U in the 21st Variation. As shown in FIG25, the pixel section 13U in the 21st Variation differs from the pixel section 13J shown in FIG14 in that a phase difference lens 161 is provided instead of the crystal lens 151.

[0094] The phase difference lens 161 is a lens that uses metamaterials to construct a phase difference of incident light to concentrate light. Alternatively, an anti-reflective layer 162 can be provided on the light incident surface of the phase difference lens 161.

[0095] In the pixel section 13U of the 21st variation, even when a phase difference lens 161 is used instead of a hemispherical convex lens, i.e., a crystal lens 151, the incident light can be focused for each pixel 12. Therefore, even in the pixel section 13T of the 21st variation, like the pixel section 13J shown in FIG14, color mixing between adjacent pixels 12 can be suppressed.

[0096] (22nd Variation) Figure 26 is a longitudinal sectional view showing the cross-sectional structure of the pixel section 13V in the 22nd Variation. As shown in Figure 26, the difference between the pixel section 13V in the 22nd Variation and the pixel section 13J shown in Figure 14 is that the pixel NP and the phase difference pixel PP are usually coexisting.

[0097] The phase difference pixel PP is composed of a plurality of sub-pixels SP and a single crystal lens 151 disposed on the plurality of sub-pixels SP. The phase difference pixel PP can detect the distance to the subject based on the pixel signals obtained from each of the plurality of sub-pixels SP. The low refractive region 140 is not disposed between the sub-pixels SP, but is disposed between the phase difference pixel PP and the normal pixel NP. Even when the pixel section 13V of the 22nd variation includes the normal pixel NP and the phase difference pixel PP, it can suppress color mixing between the phase difference pixel PP and the normal pixel NP, or between the normal pixels NP, just like the pixel section 13J shown in FIG14.

[0098] Furthermore, in the pixel section 13V of the 22nd variation, the crystal lens 151 provided in the phase difference pixel PP is positioned at a height higher than that provided in the crystal lens 151 provided in the normal pixel NP. Accordingly, the crystal lens 151 provided in the phase difference pixel PP can control the focal position on the crystal lens 151 side by improving the separation ratio in the sub-pixel SP. Therefore, the pixel section 13V of the 22nd variation can improve the phase difference amount of the phase difference pixel PP.

[0099] (23rd Variation) Figure 27 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section 13W in the 23rd Variation. As shown in Figure 27, the difference between the pixel section 13W in the 23rd Variation and the pixel section 13J shown in Figure 14 is that the normal pixel NP and the phase difference pixel PP are coexisting. Since the normal pixel NP and the phase difference pixel PP have already been described with respect to the pixel section 13V in the 22nd Variation, the description is omitted here.

[0100] In the pixel section 13W of the 23rd variation, a low-refractive-index layer 142 is provided between the phase difference pixel PP and the normal pixel NP, with a width wider than the low-refractive-index region 140 provided between the normal pixels NP. Accordingly, the phase difference pixel PP can control the focus on the crystal lens 151 side by improving the separation ratio in the sub-pixel SP through the waveguide effect of the low-refractive-index layer 142. Therefore, the pixel section 13W of the 23rd variation can improve the phase difference of the phase difference pixel PP.

[0101] Here, referring to FIGS. 28A to 29C, a planar arrangement example of the phase difference pixel PP in the pixel section 13V of the 22nd variation and the pixel section 13W of the 23rd variation will be described. FIGS. 28A to 28C are top views showing an example of a planar arrangement when the phase difference pixel PP and the normal pixel NP are mixed. FIGS. 29A to 29C are top views showing an example of a planar arrangement when only the phase difference pixel PP is present.

[0102] As shown in Figures 28A, 28B, 29A, and 29B, for example, when the pixel pitch of the phase difference pixel PP is set to p, it can be set to a size of 2p × 1p. In this case, the phase difference pixel PP can be composed of two sub-pixels SP.

[0103] The phase difference pixel PP can be individually set in the normal pixel NP as shown in FIG28A, or it can be arranged in multiples in the normal pixel NP as shown in FIG28B. Furthermore, the phase difference pixel PP can be set in the area where only the phase difference pixel PP is arranged, as shown in FIG29A and FIG29B. In this case, the phase difference pixel PP can be arranged in a matrix as shown in FIG29A, or it can be arranged staggered with each other as shown in FIG29B.

[0104] Furthermore, as shown in Figures 28C and 29C, for example, when the pixel pitch of the phase difference pixel PP is set to p, it can be set to a size of 2p×2p. In this case, the phase difference pixel PP can be composed of 4 sub-pixels SP.

[0105] The phase difference pixel PP can be individually set in the normal pixel NP as shown in FIG28C. Alternatively, the phase difference pixel PP can be set in the area where only the phase difference pixels PP are arranged, as shown in FIG29C. In this case, the phase difference pixels PP can also be arranged in a matrix as shown in FIG29C.

[0106] <3. Second Embodiment> (3.1. Pixel Unit Structure) Next, referring to FIG30, the cross-sectional structure of the pixel unit 21 of the second embodiment disclosed herein will be described. FIG30 is a longitudinal sectional view showing the cross-sectional structure of the pixel unit 21.

[0107] As shown in FIG30, the pixel unit 21 includes a semiconductor substrate 110, an intermediate layer 120, a color filter 130, an insulating layer 141, a crystal lens 151, and an anti-reflective film 152.

[0108] The semiconductor substrate 110 is a silicon (Si) substrate having a thickness of, for example, 1 μm to 6 μm. On the semiconductor substrate 110, a photoelectric conversion unit 111 is provided for each pixel 12 to generate a signal charge corresponding to the amount of incident light received. The photoelectric conversion unit 111 is, for example, a photodiode, constructed by providing a second conductivity type (e.g., N-type) semiconductor region within a first conductivity type (e.g., P-type) semiconductor region for each pixel 12.

[0109] Furthermore, the photoelectric conversion units 111 provided for each pixel 12 are electrically separated from each other by pixel separation walls 112 made of insulating material. The pixel separation walls 112 may also be provided by extending insulating materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON) in the thickness direction of the semiconductor substrate 110.

[0110] Furthermore, a light-shielding portion 113 is provided on the pixel separation wall 112. Specifically, the light-shielding portion 113 is provided on the middle layer 120 side of the pixel separation wall 112. For example, the light-shielding portion 113 may be made of a conductive material capable of blocking light, such as tungsten (W), aluminum (Al), copper (Cu), titanium nitride (TiN), or polysilicon (poly-Si), or may be made of an organic resin material containing carbon black pigment or titanium black pigment. The light-shielding portion 113 can suppress color mixing between adjacent pixels 12 by blocking light leaking to adjacent pixels 12.

[0111] The intermediate layer 120 is a functional layer disposed on the semiconductor substrate 110 with an insulating material. The intermediate layer 120 is disposed on the semiconductor substrate 110 by low refractive region 140 for each pixel 12.

[0112] In the second embodiment, the intermediate layer 120 is formed by sequentially stacking a fixed charge layer 124, a reflection control layer 123, and a dielectric layer 122 from the semiconductor substrate 110 side.

[0113] The dielectric layer 122 is made of a dielectric material and extends from the pixel separation wall 112 along the bottom and side surfaces of the light-shielding portion 113 and the lower surface of the color filter 130. Specifically, the dielectric layer 122 extends from the pixel separation wall 112 in such a way that it surrounds the lower surface and side surfaces of the light-shielding portion 113 disposed on the side of the intermediate layer 120 of the pixel separation wall 112. The dielectric layer 122 further extends onto the semiconductor substrate 110 and is disposed along the lower surface of the color filter 130.

[0114] The dielectric layer 122 may be made of the same insulating material (i.e., dielectric material) as the pixel separation wall 112 and formed by the same steps as the pixel separation wall 112. For example, the pixel separation wall 112 and the dielectric layer 122 may be formed by depositing silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON) using ALD (Atomic Layer Deposition). In this case, the thickness of the dielectric layer 122 provided along the side surface of the light-shielding portion 113 is at least substantially the same as the thickness of the dielectric layer 122 provided along the lower surface of the light-shielding portion 113. Furthermore, the thickness of the dielectric layer 122 provided along the lower surface of the color filter 130 is substantially the same as the thickness of the dielectric layer 122 provided along the side and lower surfaces of the light-shielding portion 113.

[0115] However, the thickness of the dielectric layer 122 disposed along the side of the light-shielding portion 113 may be thinner than the thickness of the dielectric layer 122 disposed along the lower surface of the light-shielding portion 113. In this case, the pixel portion 21 can further improve the characteristics of the pixel 12, such as color mixing suppression and quantum efficiency.

[0116] The fixed charge layer 124 is made of a material with a negative fixed charge and is disposed between the dielectric layer 122 and the semiconductor substrate 110. Specifically, the fixed charge layer 124 may also be made of a high dielectric material with a negative fixed charge, such as hafnium oxide (HfO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), tantalum oxide (Ta2O5), titanium oxide (TiO2), magnesium oxide (MgO), yttrium oxide (Y2O3), or lanthanide oxides. The fixed charge layer 124 can form a region where positive charge is accumulated at the interface with the semiconductor substrate 110 due to the negative fixed charge, thereby suppressing the generation of dark current between the dielectric layer 122 and the semiconductor substrate 110.

[0117] Furthermore, the fixed charge layer 124 may extend and be disposed between the dielectric layer 122 disposed on the side of the light-shielding portion 113, the pixel separation wall 112 continuous in the dielectric layer 122, and the semiconductor substrate 110. For example, the fixed charge layer 124 may also be disposed between the dielectric layer 122 and the pixel separation wall 112 made of an insulating material (i.e., dielectric material) and the semiconductor substrate 110. In this case, the fixed charge layer 124 can also suppress the generation of dark current between the dielectric layer 122 and the pixel separation wall 112 and the semiconductor substrate 110 by means of negative fixed charge.

[0118] The reflection control layer 123 is made of a material having a refractive index higher than that of the dielectric layer 122 and lower than that of the semiconductor substrate 110, and is disposed between the fixed charge layer 124 and the dielectric layer 122. For example, the reflection control layer 123 may also be disposed between the fixed charge layer 124 disposed on the front side of the semiconductor substrate 110 and the dielectric layer 122 disposed on the lower surface of the color filter 130. Since the reflection control layer 123 can suppress the reflection of light at the interface with the dielectric layer 122 or at the interface with the semiconductor substrate 110, the efficiency of incident light to the photoelectric conversion unit 111 can be improved.

[0119] Color filters 130 are disposed on the intermediate layer 120 for each pixel 12, so that light of the wavelength band corresponding to each pixel 12 (e.g., red light (R), green light (G), and blue light (B)) can be selectively transmitted. Color filters 130 can also be disposed in a specific RGB arrangement, such as a Bayer arrangement.

[0120] As an example, the color filter 130 can be provided by adding pigments or dyes to a transparent resin that allows visible light to pass through. As another example, the color filter 130 can also be made of a transparent filter that allows visible light to pass through, or an ND filter made by adding carbon black to a transparent resin.

[0121] In the pixel portion 21, the color filter 130 and the intermediate layer 120 are separated by a low-refractive-index region 140 extending in the thickness direction of the semiconductor substrate 110 for each pixel 12. Alternatively, in the second embodiment, the low-refractive-index region 140 only needs to separate at least one of the dielectric layer 122, the reflection control layer 123, and the fixed charge layer 124 included in the intermediate layer 120 for each pixel 12.

[0122] The low-refractive-index region 140 is a region with a refractive index lower than that of the color filter 130. For example, the low-refractive-index region 140 may also be a region with a refractive index of 1.0 or higher and 1.35 or lower. The low-refractive-index region 140 is disposed between each other of the color filters 130 disposed for each pixel 12 and between each other of the intermediate layer 120 disposed for each pixel 12. In this way, the low-refractive-index region 140 enables the color filters 130 and the intermediate layer 120 to function as waveguides consisting of a low-refractive-index material sandwiching a high-refractive-index material. Therefore, since the low-refractive-index region 140 can reflect light traveling on adjacent pixels 12 at the interface with the color filter 130 and the interface with the intermediate layer 120, the efficiency of incident light to the photoelectric conversion unit 111 can be improved.

[0123] The low-refractive-index region 140 can be made of any material as long as its refractive index is lower than that of the color filter 130. For example, the low-refractive-index region 140 can be voids, or it can be made of inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON), or resin-based materials such as styrene-based resins, acrylic resins, styrene-acrylic copolymer resins, or siloxane resins. Furthermore, the low-refractive-index region 140 can also be made of so-called low-k materials such as SiOF, SiOC, or porous silicon dioxide.

[0124] An insulating layer 141 is disposed on the color filter 130 using an insulating material. For example, the insulating layer 141 is disposed on the color filter 130 by forming a film of silicon oxide (SiO2) or the like. Accordingly, by forming a film of the insulating layer 141 on the color filters 130 separated by each pixel 12 with a high coverage ratio, the low refractive region 140 between the color filters 130 is left as a gap, and the upper end is directly sealed without embedding.

[0125] A crystal carrier lens 151 is disposed on the insulating layer 141 for each pixel 12. The crystal carrier lens 151 may also be formed of a resin-based material such as styrene-based resin, acrylic resin, styrene-acrylic copolymer resin, or silicone resin. The crystal carrier lens 151 can concentrate the light incident on the pixel 12, and the photoelectric conversion unit 111 can make the light incident on the pixel 12 efficiently.

[0126] Alternatively, an antireflective film 152 may be formed on the surface of the crystal lens 151. The antireflective film 152 is, for example, a dielectric multilayer film. The antireflective film 152 can suppress the reflection of light incident on the crystal lens 151.

[0127] Here, referring to FIG31, the dimensions of the light-shielding portion 113, the dielectric layer 122, the pixel separation wall 112, and the low-refractive region 140 will be described in more detail. FIG31 is an enlarged longitudinal sectional view of the vicinity of the light-shielding portion 113 in FIG30.

[0128] As shown in FIG31, the thickness of the dielectric layer 122 disposed along the lower surface of the light-shielding portion 113 is set as t1, the thickness of the dielectric layer 122 disposed along the side surface of the light-shielding portion 113 is set as t2, and the thickness of the dielectric layer 122 disposed along the lower surface of the color filter 130 is set as t3. At this time, the dielectric layer 122 can be disposed in such a way that t1=t2, or further in such a way that t1=t2=t3. This dielectric layer 122 can be formed by using an ALD (Atomic Layer Deposition) which can deposit films with high precision and uniformity for any structure. Furthermore, the dielectric layer 122 can also be disposed in such a way that t2 is less than t1 or t3. By making the thickness of the dielectric layer 122 disposed along the side surface of the light-shielding portion 113 thinner, the pixel portion 21 can suppress color mixing between adjacent pixels 12, and thereby improve the quantum efficiency of the photoelectric conversion portion 111.

[0129] Furthermore, the thickness of the dielectric layer 122 disposed along both sides of the light-shielding portion 113 and the width of the light-shielding portion 113 are combined to form W1, and the width of the pixel separation wall 112 is set to w2. At this time, the dielectric layer 122 and the pixel separation wall 112 can also be disposed in such a way that W1 > W2. By disposing the light-shielding portion 113 with a width in which the combined width of the light-shielding portion 113 and the dielectric layer 122 is greater than the width of the pixel separation wall 112, color mixing between adjacent pixels 12 can be suppressed.

[0130] Furthermore, the width of the light-shielding portion 113 is set to W3, and the width of the low-refractive region 140 is set to W4. At this time, the light-shielding portion 113 and the low-refractive region 140 can be set in a manner where W3=W4, or in a manner where W3<W4. By setting the light-shielding portion 113 with a width at least the same as the width of the low-refractive region 140, color mixing between adjacent pixels 12 can be suppressed.

[0131] (3.2. Variation Examples) Next, referring to Figures 32A to 67, the first to 23 variations of the pixel unit 21 of the camera device 100 in this embodiment will be described.

[0132] (First Variation Example) Figures 32A to 32F are longitudinal sectional views showing variations in the configuration near the light-shielding portion 113. As shown in Figures 32A to 32F, in the pixel portion 21 of the first variation example, variations can also be applied to the configuration near the light-shielding portion 113.

[0133] As shown in FIG32A, the light-shielding portion 113 may also be configured such that the width W3 of the light-shielding portion 113 is wider than the width W4 of the low-refractive region 140. By configuring the light-shielding portion 113 with a wider width, color mixing between adjacent pixels 12 can be suppressed.

[0134] As shown in FIG32B, the light-shielding portion 113 may extend upward along the inner side of the opening of the low-refractive region 140. For example, the light-shielding portion 113 may also extend upward along the inner side of the concave structure formed by attaching a conductive material to the inner side of the concave structure formed by the dielectric layer 122. Even in this case, the light-shielding portion 113 can suppress color mixing between adjacent pixels 12.

[0135] As shown in Figures 32C and 32D, the light-shielding part 113 and the low-refractive area 140 can also be arranged in a way that they do not contact each other.

[0136] As an example, as shown in FIG32C, a dielectric layer 122 may also be provided between the light-shielding portion 113 and the low-refractive region 140. In this case, the dielectric layer 122 can protect the light-shielding portion 113 from the effects that may occur during the step of forming the low-refractive region 140, thus preventing the degradation of the characteristics of the light-shielding portion 113.

[0137] As another example, as shown in FIG32D, a low-refractive-index layer 143 made of an insulating material with a refractive index lower than that of the dielectric layer 122 may be provided between the light-shielding portion 113 and the low-refractive-index region 140. In this case, since the low-refractive-index layer 143 can protect the light-shielding portion 113 from the possible effects that may occur during the step of forming the low-refractive-index region 140, the degradation of the characteristics of the light-shielding portion 113 can be suppressed. Furthermore, since the low-refractive-index layer 143 can form a waveguide path consisting of a low-refractive-index material sandwiching a high-refractive-index material extending directly above the light-shielding portion 113, the efficiency of incident light to the photoelectric conversion unit 111 can be improved.

[0138] As shown in FIG32E, an anti-diffusion layer 114 made of Ti or TiN may also be provided between the light-shielding portion 113 and the dielectric layer 122. The anti-diffusion layer 114 can prevent the interdiffusion of atoms between the dielectric layer 122 and the light-shielding portion 113. Therefore, the anti-diffusion layer 114 can prevent the degradation of the properties of the dielectric layer 122 and the light-shielding portion 113.

[0139] As shown in FIG32F, a cover layer 115 made of Ti or TiN may also be provided on the upper surface of the light-shielding portion 113. Since the cover layer 115 can protect the light-shielding portion 113 from the effects that may occur during the step of forming the low-refractive region 140, the characteristics of the light-shielding portion 113 can be prevented from deteriorating. Furthermore, since the cover layer 115 made of Ti or TiN, like the light-shielding portion 113, can block light leaking to adjacent pixels 12, it can also suppress color mixing between adjacent pixels 12.

[0140] (Second Variation) Figure 33 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 21A in the second variation. As shown in Figure 33, the difference between the pixel portion 21A in the second variation and the pixel portion 21 shown in Figure 30 is that the light-shielding portion 113 is provided in an inverted cone shape.

[0141] Specifically, the light-shielding portion 113 may also be provided in an inverted cone shape that widens towards the upper side where the color filter 130 and the low refractive region 140 are provided. Since the light-shielding portion 113 with this inverted cone shape is easier to form than the light-shielding portion 113 with a non-inverted cone shape, the manufacturing process of the pixel portion 21A can be made easier.

[0142] (Third Variation) Figure 34 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 21B in the third variation. As shown in Figure 34, the pixel portion 21B in the third variation differs from the pixel portion 21A shown in Figure 33 in that the low-refractive region 140 is further provided in a cone shape.

[0143] Specifically, the low-refractive region 140 may also be provided in a tapered shape that tapers toward the upper side of the lens carrier 151. When this tapered low-refractive region 140 is formed as a gap, the upper end can be easily sealed by the insulating layer 141, thus reducing the difficulty of the manufacturing process of the pixel section 21A.

[0144] (4th variation) FIG35 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 21C in the 4th variation. As shown in FIG35, the pixel portion 21C in the 4th variation differs from the pixel portion 21 shown in FIG30 in that the pixel separation wall 112 extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110.

[0145] Specifically, the pixel separation wall 112 extends to one half of the semiconductor substrate 110, and like the pixel portion 21 shown in FIG30, it can electrically separate the photoelectric conversion portions 111 of adjacent pixels 12. Therefore, the pixel portion 21C of the fourth variation, like the pixel portion 21 shown in FIG30, can suppress color mixing between adjacent pixels 12.

[0146] (Fifth Variation) Figure 36 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 21D in the fifth variation. As shown in Figure 36, the difference between the pixel portion 21D in the fifth variation and the pixel portion 21 shown in Figure 30 is that the insulating layer 141 is not provided.

[0147] Specifically, when the low-refractive region 140 is a gap, the pixel unit 21D can form the low-refractive region 140 by sealing the upper end of the gap with the crystal lens 151. Furthermore, when the low-refractive region 140 is made of a low-refractive material with a refractive index lower than that of the color filter 130, the pixel unit 21D can form the low-refractive region 140 by embedding low-refractive materials between the color filters 130 and between the intermediate layers 120.

[0148] Accordingly, since the pixel portion 21D of the fifth variation can appropriately form a low refractive region 140, it can suppress color mixing between adjacent pixels 12, just like the pixel portion 21 shown in FIG30.

[0149] (Sixth Variation) FIG37 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 21E in the sixth variation. As shown in FIG37, the pixel portion 21E in the sixth variation differs from the pixel portion 21 shown in FIG30 in that a low-refractive-index layer 143 made of an insulating material with a refractive index lower than that of the dielectric layer 122 is provided between the light-shielding portion 113 and the low-refractive-index region 140.

[0150] Specifically, the low-refractive-index layer 143 is composed of inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON), which have a refractive index lower than that of the dielectric layer 122, or resin-based materials such as styrene-based resins, acrylic resins, styrene-acrylic copolymer resins, or siloxane resins. Because the low-refractive-index layer 143 can protect the light-shielding portion 113 from the potential effects that may occur during the formation of the low-refractive-index region 140, it can suppress the degradation of the characteristics of the light-shielding portion 113. Furthermore, the low-refractive-index layer 143 can form a waveguide path consisting of a low-refractive-index material sandwiching a high-refractive-index material, extending directly above the light-shielding portion 113, thereby improving the efficiency of light incident on the photoelectric conversion unit 111.

[0151] (7th variation) Figure 38 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 21F in the 7th variation. As shown in Figure 38, the difference between the pixel portion 21F in the 7th variation and the pixel portion 21 shown in Figure 30 is that the low refractive region 140 is not a gap, but is provided as a low refractive layer 142.

[0152] The low-refractive-index layer 142 is made of a material with a refractive index lower than that of the color filter 130, and is disposed between the color filters 130 disposed in relation to each pixel 12 and between the intermediate layers 120. The material with a refractive index lower than that of the color filter 130 is, for example, inorganic materials such as silicon oxide (SiO2), silicon nitride (SiN), or silicon oxynitride (SiON), resin materials such as styrene-based resins, acrylic resins, styrene-acrylic copolymer resins, or siloxane resins, or low-k materials such as SiOF, SiOC, or porous silicon dioxide. Like the low-refractive-index region 140 which is disposed as a gap, the low-refractive-index layer 142 enables the color filter 130 and the intermediate layer 120 to function as a waveguide path consisting of a low-refractive-index material sandwiching a high-refractive-index material.

[0153] Accordingly, in the seventh variation, the pixel portion 21F can reflect light traveling on adjacent pixels 12 at the interface between the low-refractive layer 142 and the color filter 130, and at the interface between the low-refractive layer 142 and the intermediate layer 120. Therefore, the pixel portion 21F in the seventh variation, like the pixel portion 21 shown in FIG30, can suppress color mixing between adjacent pixels 12.

[0154] (Eighth Variation) Figures 39 to 41 are longitudinal sectional views showing the cross-sectional configuration of pixel units 21G, 21H, and 21I in the eighth variation. As shown in Figures 39 to 41, in order to more effectively incident light with a larger incident angle onto the photoelectric conversion unit 111, the pixel units 21G, 21H, and 21I in the eighth variation are configured to be positioned above the semiconductor substrate 110 (i.e., on the light incident surface side) in the light incident direction. This kind of displacement is called pupil correction, etc., and is implemented, for example, in pixels 12 located in areas with a larger light incident angle, such as the periphery of the pixel area.

[0155] Furthermore, in the pixel portions 21G, 21H, and 21I of the eighth variation, the low-refractive region 140 is not a gap, but is provided as a low-refractive layer 142. When the low-refractive region 140 is provided as a low-refractive layer 142, compared with the case where the low-refractive region 140 is a gap, the pixel portions 21G, 21H, and 21I are more likely to shift the structure on the upper side of the semiconductor substrate 110.

[0156] Specifically, as shown in FIG39, the crystal lens 151 may also be shifted relative to the color filter 130 and the low refractive layer 142 in the direction of light incidence.

[0157] As shown in FIG40, the crystal lens 151, the color filter 130, and the low refractive layer 142 can be displaced relative to the dielectric layer 122 in the direction of light incidence. Furthermore, the crystal lens 151 can also be displaced relative to the color filter 130 and the low refractive layer 142 in the direction of light incidence.

[0158] As shown in FIG41, the crystal lens 151, color filter 130, low refractive layer 142, and dielectric layer 122 can be displaced relative to the reflection control layer 123 in the light incident direction. Furthermore, the crystal lens 151, color filter 130, and low refractive layer 142 can also be displaced relative to the dielectric layer 122 in the light incident direction, and the crystal lens 151 is further displaced relative to the color filter 130 and low refractive layer 142 in the light incident direction.

[0159] Accordingly, the pixel units 21G, 21H, and 21I of the eighth variation can more effectively incident light with a larger incident angle onto the photoelectric conversion unit 111. Therefore, even for pixels 12 at the periphery of the pixel area, the pixel units 21G, 21H, and 21I of the eighth variation can more effectively incident light onto the photoelectric conversion unit 111.

[0160] (9th Variation) Figure 42 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section 21J in the 9th Variation. As shown in Figure 42, the difference between the pixel section 21J in the 9th Variation and the pixel section 21 shown in Figure 30 is that the pixel NP and the phase difference pixel PP are usually coexisting.

[0161] Specifically, the phase difference pixel PP is composed of a plurality of sub-pixels SP and a single crystal lens 151 disposed on the plurality of sub-pixels SP. The phase difference pixel PP can detect the distance to the subject based on the pixel signals obtained from each of the plurality of sub-pixels SP. The low refractive index region 140 is not disposed between the sub-pixels SP, but is disposed between the phase difference pixel PP and the normal pixel NP. The pixel section 21J of the 9th variation can suppress color mixing between the phase difference pixel PP and the normal pixel NP, or between the normal pixels NP.

[0162] (10th Variation) Figure 43 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 21K in the 10th Variation. As shown in Figure 43, the difference between the pixel portion 21K in the 10th Variation and the pixel portion 21J shown in Figure 42 is that each sub-pixel SP is not separated by the pixel separation wall 112.

[0163] In the pixel section 21K of the 10th variation, each sub-pixel SP is electrically separated from the others by introducing a conductive impurity pattern into the semiconductor substrate 110. For example, each sub-pixel SP can also be electrically separated from the others by forming a region with lower conductivity where no conductive impurities are introduced. Accordingly, the pixel section 21K of the 10th variation is similar to the pixel section 21J shown in FIG42, and a portion of the pixels 12 can function as a phase difference pixel PP for detecting the distance between itself and the subject.

[0164] (11th Variation) FIG44 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 21L in the 11th Variation. As shown in FIG44, the pixel portion 21L in the 11th Variation differs from the pixel portion 21J shown in FIG42 in that the pixel separation wall 112 extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110.

[0165] Specifically, the pixel separation wall 112 extends to one half of the semiconductor substrate 110, and like the pixel section 21J shown in FIG42, it can electrically separate the photoelectric conversion sections 111 of adjacent pixels 12 and sub-pixels SP. Therefore, the pixel section 21L of the 11th variation is the same as the pixel section 21J shown in FIG42, and a portion of the pixels 12 can function as phase difference pixels PP that detect the distance between themselves and the subject.

[0166] (12th Variation) Figure 45 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 21M in the 12th Variation. As shown in Figure 45, the pixel portion 21M in the 12th Variation differs from the pixel portion 21J shown in Figure 42 in that the height of the crystal lens 151 disposed on the phase difference pixel PP is higher than the height of the crystal lens 151 disposed on the normal pixel NP.

[0167] In the pixel section 21M of the 12th variation, the crystal lens 151 provided in the phase difference pixel PP can be shifted towards the crystal lens 151 side compared to the crystal lens 151 provided in the normal pixel NP. Accordingly, since the pixel section 21M of the 12th variation can improve the separation ratio in the sub-pixel SP, the phase difference amount of the phase difference pixel PP can be increased.

[0168] (13th Variation) Figure 46 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion 21N in the 13th Variation. As shown in Figure 46, the pixel portion 21N in the 13th Variation differs from the pixel portion 21L in the 11th Variation shown in Figure 44 in that the pixel separation wall 112A is made of a different material than the pixel separation wall 112.

[0169] Specifically, the pixel separation wall 112 disposed between the phase difference pixel PP and the normal pixel NP, or between the normal pixels NP, extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110. On the other hand, the pixel separation wall 112A disposed between the sub-pixels SP uses an insulating material different from the pixel separation wall 112 and extends in the thickness direction of the semiconductor substrate 110 to one half of the semiconductor substrate 110. The pixel separation wall 112 can be made of an insulating material with a higher refractive index than the insulating material constituting the pixel separation wall 112. For example, the pixel separation wall 112A can also be made of an insulating material with a high refractive index such as TaO, TiO2, or HfO. Accordingly, in the pixel portion 21N of the 13th variation, since the separation ratio in the sub-pixels SP can be improved, the phase difference amount of the phase difference pixel PP can be improved.

[0170] (14th Variation) FIG47 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion 21O in the 14th Variation. As shown in FIG47, the pixel portion 21O in the 14th Variation differs from the pixel portion 21J shown in FIG42 in that a low-refractive layer 142 with a width wider than the low-refractive layer 142 between ordinary pixels NP is disposed between the phase difference pixel PP and the ordinary pixel NP.

[0171] In the pixel section 21O of the 14th variation, the phase difference pixel PP can narrow the waveguide path by using the low refractive layer 142, thereby shifting the focal position towards the crystal lens 151 side compared to the ordinary pixel NP. Accordingly, since the pixel section 21O of the 14th variation can improve the separation ratio in the sub-pixel SP, the phase difference amount of the phase difference pixel PP can be increased.

[0172] The planar arrangement of the phase difference pixels PP in the pixel section 21J to 21O of the 9th to 14th variations can also be the same as the planar arrangement examples shown in FIG28A to FIG28C and FIG29A to FIG29C.

[0173] Here, referring to FIGS. 48A to 48I, an example of the planar arrangement of the color filter 130 of the pixel section 21 in the second embodiment will be described. FIGS. 48A to 48I are top views showing an example of the planar arrangement of the color filter 130 of the pixel section 21.

[0174] For example, as shown in FIG48A, the color filter 130 can arrange four pixels, namely one red (Red:R) pixel, two diagonally arranged green (Green:G) pixels and one blue (Blue:B) pixel, as a unit.

[0175] For example, as shown in FIG48B, the color filter 130 may also arrange four red (R) pixels in a 2×2 configuration, eight green (G) pixels in a 2×2 pixel group diagonally configured, and four blue (B) pixels in a 2×2 configuration as a unit.

[0176] For example, as shown in FIG48C, the color filter 130 may also arrange 9 red (R) pixels in a 3×3 configuration, 18 green (G) pixels in a 3×3 pixel group diagonally configured, and 9 blue (B) pixels in a 3×3 configuration as a unit.

[0177] For example, as shown in FIG48D, the color filter 130 may also arrange 16 red (R) pixels in a 4×4 configuration, 32 green (G) pixels in a 4×4 pixel group diagonally configured, and 16 blue (B) pixels in a 4×4 configuration as a unit.

[0178] For example, as shown in FIG48E, the color filter 130 can combine and arrange red (R) pixels, green (G) pixels, blue (B) pixels, and white (W) pixels. Specifically, the red (R) pixels, green (G) pixels, and blue (B) pixels can be paired with white (W) pixels and arranged in a way that the same color is diagonally opposite each other.

[0179] For example, as shown in FIG48F, the color filter 130 may also arrange four cyan (C) pixels in a 2×2 configuration, eight yellow (Y) pixels in a 2×2 pixel group diagonally, and four magenta (M) pixels in a 2×2 configuration as a unit. Cyan, yellow, and magenta are colors used in a color representation method called subtractive color mixing.

[0180] For example, as shown in FIG48G, the color filter 130 may also arrange four cyan (C) pixels, four yellow (Y) pixels, four magenta (M) pixels, and four green (G) pixels in a 2×2 configuration as a unit.

[0181] For example, as shown in FIG48H, the color filter 130 can combine and arrange red (R) pixels, green (G) pixels, blue (B) pixels, cyan (C) pixels, yellow (Y) pixels, and magenta (M) pixels. Specifically, the red (R) pixels, green (G) pixels, blue (B) pixels, cyan (C) pixels, yellow (Y) pixels, and magenta (M) pixels can be paired with pixels of the same color and arranged in a way that the pixels of the same color are diagonally opposite each other.

[0182] For example, as shown in FIG48I, the color filter 130 can combine and arrange red (R) pixels, green (G) pixels, blue (B) pixels, cyan (C) pixels, yellow (Y) pixels, and magenta (M) pixels. Specifically, the red (R) pixels, green (G) pixels, blue (B) pixels, cyan (C) pixels, yellow (Y) pixels, and magenta (M) pixels can be paired with pixels of complementary colors and arranged in a way that allows pixels of the same color to be arranged diagonally opposite each other.

[0183] Figures 49A to 49F show a combination of a planar configuration example of the color filter 130 described with reference to Figures 48A to 48I, and a planar configuration example of a normal pixel NP or a phase difference pixel PP. Figures 49A to 49F are top views showing an example of a combination of the color filter 130 and a normal pixel NP or a phase difference pixel PP.

[0184] As shown in Figures 49A to 49C, the pixel unit 21 may be composed of a normal pixel NP on which a 1×1 crystal lens 151 is mounted. At this time, the arrangement of the color filters 130 may be the planar configuration shown in Figure 48A (Figure 49A), the planar configuration shown in Figure 48B (Figure 49B), or the planar configuration shown in Figure 48D (Figure 49C), or the RGBW configuration shown in Figure 48E, the CMY configuration shown in Figure 48F, or the RGBCMY configuration shown in Figure 48H or Figure 48I.

[0185] As shown in Figures 49D and 49E, the pixel unit 21 may be composed of phase difference pixels PP on which a 2×2 crystal lens 151 is mounted on a pixel of the same color. In this case, the arrangement of the color filters 130 may also be a planar configuration as shown in Figure 48B (Figure 49D) or a planar configuration as shown in Figure 48D (Figure 49E).

[0186] As shown in FIG49F, the pixel unit 21 may be composed of a phase difference pixel PP on which a 2×1 crystal lens 151 is mounted on a pixel of the same color. At this time, the arrangement of the color filter 130 may also be a planar configuration such that two adjacent pixels are of the same color and the ratio of red pixels, green pixels and blue pixels is 1:2:1.

[0187] (15th Variation) Figure 50 is a top view illustrating the structure of the pixel portion 21P in the 15th variation. As shown in Figure 50, the cut-off line extending in the arrangement direction (horizontal direction in Figure 50) of the matrix-arranged pixels 12 is designated as line A-AA, and the cut-off line extending diagonally in the direction of the pixels 12 is designated as line B-BB. Figure 51 is a longitudinal sectional view comparing the cross-sectional structure of line A-AA and the cross-sectional structure of line B-BB in Figure 50.

[0188] As shown in FIG51, in the pixel portion 21P of the 15th variation, the depth and width of the light-shielding portion 113C formed between the diagonal pixels 12 are different from the depth and width of the light-shielding portion 113S formed between the pixels 12 in the arrangement direction.

[0189] Specifically, the light-shielding portion 113C disposed between the diagonally opposite pixels 12 can be disposed at a deeper position in the semiconductor substrate 110 than the light-shielding portion 113S disposed between the pixels 12 in the arrangement direction, and its width can be larger. For example, the lower end of the light-shielding portion 113C disposed between the diagonally opposite pixels 12 can be disposed further lower than the lower end of the light-shielding portion 113S disposed between the pixels 12 in the arrangement direction. Furthermore, the width of the light-shielding portion 113C disposed between the diagonally opposite pixels 12 can be larger than the width of the light-shielding portion 113S disposed between the pixels 12 in the arrangement direction. In addition, the upper end of the light-shielding portion 113C disposed between the diagonally opposite pixels 12 can be disposed further lower than the upper end of the light-shielding portion 113S disposed between the pixels 12 in the arrangement direction, or it can be disposed on the same surface.

[0190] The reason is believed to be that, since the spacing between the diagonal pixels 12 is wider than the spacing between the pixels 12 in the alignment direction, it is easier to etch the semiconductor substrate 110 between the diagonal pixels 12 than between the pixels 12 in the alignment direction during the step of forming the pixel separation wall 112. Furthermore, the etching of the semiconductor substrate 110 optimizes the light-shielding portion 113S between the pixels 12 in the alignment direction. Therefore, the shape of the bottom surface of the light-shielding portion 113C between the diagonal pixels 12 is not optimized, and may become a circular shape with rounded corners.

[0191] Here, the method for forming the pixel portion 21P of the 15th variation will be described with reference to FIGS. 52 to 64. FIGS. 52 to 64 are longitudinal sectional views illustrating the steps for forming the pixel portion 21P of the 15th variation. In FIGS. 52 to 64, "Center" refers to the central region of the pixel portion 21P. "Edge" refers to the peripheral region of the pixel portion 21P. Also, "OPB" refers to the optical black region provided on the pixel portion 21P. The optical black region is the region used for detecting dark noise by the light-blocking optical conversion unit 111.

[0192] First, as shown in FIG52, openings 112HS and 112HC are formed by etching the circuit layer 200, which includes pixel transistors and wiring, and the stacked semiconductor substrate 110. For example, openings 112HS and 112HC can be arranged to penetrate the semiconductor substrate 110. Opening 112HS is an opening for setting pixel separation walls 112 between pixels 12 in the arrangement direction, and opening 112HC is an opening for setting pixel separation walls 112 between pixels 12 in the diagonal direction. Since the spacing between pixels 12 in the diagonal direction is wider than the spacing between pixels 12 in the arrangement direction, the width of opening 112HC is wider than the width of opening 112HS.

[0193] Next, as shown in FIG53, a protective film 310 is formed on the exposed surface of the semiconductor substrate 110 by means of ALD. The protective film 310 is made of, for example, silicon oxide (SiO2), and is formed with uniform thickness on the exposed surface of the semiconductor substrate 110 including the bottom surface and the inner surface of the openings 112HS and 112HC.

[0194] Next, as shown in FIG54, a resist layer 320 is formed in such a way that it is embedded with openings 112HS and 112HC and covers the front side of the semiconductor substrate 110. The resist layer 320 may also be, for example, an i-line resist.

[0195] Next, as shown in FIG55, the resist layer 320 is retracted until the protective film 310 disposed on the front side of the semiconductor substrate 110 is exposed by performing full-surface exposure. At this time, more resist layer 320 in the opening 112HC than in the opening 112HS is retracted by exposure. This is because the width of the opening 112HC is wider than the width of the opening 112HS.

[0196] Subsequently, as shown in FIG56, the entire surface is etched (etch-back). In this way, the amount of retraction of the resist layer 320 from the front side of the semiconductor substrate 110 is controlled to the target depth.

[0197] Next, as shown in FIG57, the protective film 310 not covered by the resist layer 320 is removed by etching with DHF (dilute hydrofluoric acid).

[0198] Next, as shown in FIG58, the opening width of the openings 112HC and 112HS is widened by isotropic etching of the protective film 310 of the semiconductor substrate 110 and the area not covered by the resist layer 320 through CDE (Chemical Dry Etching).

[0199] After that, as shown in Figure 59, the protective film 310 and the resist layer 320 are removed.

[0200] Next, as shown in FIG60, a fixed charge layer 124 is formed by means of an ALD following the shape of the semiconductor substrate 110. For example, the fixed charge layer 124 is formed with a uniform thickness on the exposed surface of the semiconductor substrate 110 including the bottom surface and the inner surface of the openings 112HC and 112HS. Furthermore, a reflection control layer 123 is formed on the fixed charge layer 124 disposed on the front surface of the semiconductor substrate 110.

[0201] Next, as shown in FIG61, an insulating material such as SiO2 is deposited on the fixed charge layer 124 by ALD, embedding a portion of the openings 112HC and 112HS. This forms the pixel separation wall 112. At this time, the openings 112HC and 112HS are not completely embedded, and a portion of the concave structure remains on the pixel separation wall 112. The width and depth of the remaining concave structure of the opening 112HC are greater than those of the opening 112HS.

[0202] Next, as shown in FIG62, the thickness of the insulating material on the reflection control layer 123 is controlled by the full-area etching (etch-back) of CDE to form a dielectric layer 122.

[0203] Next, as shown in FIG63, a light-shielding film 330 is formed on the dielectric layer 122 in such a way that the remaining concave structure of the openings 112HC and 112HS is embedded. The light-shielding film 330 may be composed of, for example, a stacked structure of Ti or TiN to prevent atomic diffusion and W.

[0204] Furthermore, as shown in FIG64, the light-shielding film 330 in the area outside the openings 112HC and 112HS is removed by full-surface etching (etching back). Thereby, a light-shielding portion 113 is formed inside the openings 112HC and 112HS.

[0205] Through the above steps, the light-blocking portion 113C provided between the diagonally opposite pixels 12 is formed at a position deeper than the light-blocking portion 113S provided between the pixels 12 in the arrangement direction, and is wider than the light-blocking portion 113S.

[0206] (16th Variation) FIG65 is a longitudinal cross-sectional view showing the area near the light-shielding portion 113 of the pixel portion in the 16th variation. As shown in FIG65, the upper end of the light-shielding portion 113 can be configured to be on the same surface as the front surface of the semiconductor substrate 110. Accordingly, the light-shielding portion 113 can more effectively suppress color mixing caused by the incident light from adjacent pixels 12. On the other hand, when the upper end of the light-shielding portion 113 is offset upward or downward from the front surface of the semiconductor substrate 110, the color mixing of adjacent pixels 12 increases, which is undesirable.

[0207] The positional relationship between the upper end of the light-shielding portion 113 and the front surface of the semiconductor substrate 110 can be formed by grinding and planarizing the light-shielding portion 113 and the upper surface of the semiconductor substrate 110 by CMP (Chemical Mechanical Polishing) after the light-shielding portion 113 is formed.

[0208] Furthermore, when the light-shielding portion 113 and the upper surface of the semiconductor substrate 110 are planarized using CMP, the configuration provided on the upper surface of the light-shielding portion 113 and the semiconductor substrate 110 is temporarily removed. Accordingly, the dielectric layer 122 on the lower surface of the color filter 130 and the dielectric layers 122 on the side and lower surfaces of the light-shielding portion 113 can be formed individually with different film thicknesses. Therefore, by controlling the film thickness of the dielectric layer 122 on the lower surface of the color filter 130 and the side and lower surfaces of the light-shielding portion 113, color mixing of adjacent pixels 12 can be more effectively suppressed.

[0209] Here, the method for forming the pixel portion of the 16th variation will be described with reference to FIGS. 66 and 67. FIGS. 66 and 67 are longitudinal sectional views illustrating the steps for forming the pixel portion of the 16th variation. In FIGS. 66 and 67, "center" refers to the central region of the pixel portion, and "edge" refers to the peripheral region of the pixel portion. Also, "OPB" refers to the optical black region provided in the pixel portion.

[0210] For example, after the formation step of the light-shielding film 330 shown in FIG. 63, as shown in FIG. 66, the dielectric layer 122, reflection control layer 123, fixed charge layer 124, and light-shielding film 330 on the semiconductor substrate 110 can also be removed by CMP. In this way, the surface of the semiconductor substrate 110 and the upper surface of the light-shielding portion 113 are aligned as the same surface.

[0211] Subsequently, as shown in FIG67, the fixed charge layer 124, the reflection control layer 123, and the dielectric layer 122 are re-formed on the semiconductor substrate 110. Thereby, in the 16th variation, the pixel portion can form the dielectric layer 122 on the lower surface of the color filter 130, and on the side and lower surfaces of the light-shielding portion 113 with optimal film thicknesses for each other.

[0212] <4. Configuration of the Electronic Device> Next, referring to FIG68, the configuration of the electronic device including the camera device 100 of this embodiment will be described. FIG68 is a block diagram showing an example of the configuration of the electronic device 1000 including the camera device 100 of this embodiment. For example, the electronic device 1000 may be a camera such as a digital camera or video camera, a mobile terminal device with camera function, or a photocopier that uses a camera device for image reading, or an electronic device assembly that uses a camera device for image extraction (photoelectric conversion unit). The camera device may be mounted in the electronic device 1000 as a single chip, or it may be mounted in the electronic device 1000 as a module that integrates the camera unit and the signal processing unit or optical system with camera function.

[0213] As shown in FIG68, the electronic device 1000 includes an optical lens 1001, a shutter device 1002, an imaging device 100, a DSP (Digital Signal Processor) circuit 1011, a frame memory 1014, a display unit 1012, a memory unit 1015, an operation unit 1013, and a power supply unit 1016. The DSP circuit 1011, the frame memory 1014, the display unit 1012, the memory unit 1015, the operation unit 1013, and the power supply unit 1016 are interconnected via a bus cable 1017.

[0214] The optical lens 1001 images the incident light from the subject onto the imaging surface of the imaging device 100. The shutter device 1002 controls the period of illumination and shading of the imaging device 100.

[0215] The camera device 100 converts the amount of incident light imaged on the camera surface by the optical lens 1001 into an electrical signal in pixels and outputs it as a pixel signal.

[0216] The DSP circuit 1011 is a signal processing circuit that performs general camera signal processing on the pixel signals output by the self-imaging device 100. The DSP circuit 1011 can also perform, for example, white balance processing, de-mosaic processing, or gamma correction processing.

[0217] Frame memory 1014 is a temporary data storage unit. Frame memory 1014 is used appropriately to store data during the signal processing of DSP circuit 1011.

[0218] The display unit 1012 is composed of a panel-type display device, such as a liquid crystal panel or an organic EL (Electro Luminescence) panel. The display unit 1012 can display moving images or still images captured by the camera device 100.

[0219] The memory unit 1015 records the dynamic or static images captured by the camera device 100 onto a memory medium such as a hard disk drive, optical disk, or semiconductor memory.

[0220] The operation unit 1013 issues operation commands to various functions of the electronic machine 1000 based on the user's operation.

[0221] The power supply unit 1016 is the operating power supply for the DSP circuit 1011, the frame memory 1014, the display unit 1012, the memory unit 1015, and the operation unit 1013. The power supply unit 1016 can appropriately supply power to these components.

[0222] <5. Application Examples> The technology disclosed herein (the technology) can be applied to various products. For example, the technology disclosed herein can also be implemented as a device mounted on any type of mobile body such as automobiles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobility vehicles, airplanes, drones, ships, and robots.

[0223] Figure 69 is a block diagram showing a schematic configuration example of a mobile body control system to which the technology disclosed herein can be applied, namely a vehicle control system.

[0224] The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in FIG69, the vehicle control system 12000 includes a drive system control unit 12010, a vehicle body system control unit 12020, an external information detection unit 12030, an internal information detection unit 12040, and an integrated control unit 12050. Furthermore, the integrated control unit 12050 is functionally configured as follows: a microcomputer 12051, an audio / image output unit 12052, and an in-vehicle network I / F (Interface) 12053.

[0225] The drive system control unit 12010 controls the operation of devices associated with the vehicle's drive system according to various programs. For example, the drive system control unit 12010 functions as a drive force generating device such as an internal combustion engine or drive motor to generate the vehicle's driving force, a drive force transmission mechanism to transmit the driving force to the wheels, a steering mechanism to adjust the vehicle's steering angle, and a braking device to generate the vehicle's braking force.

[0226] The vehicle system control unit 12020 controls the operation of various devices provided on the vehicle body according to various programs. For example, the vehicle system control unit 12020 functions as a control device for keyless start systems, smart key systems, power windows, or various lights such as headlights, taillights, brake lights, turn signals, or fog lights. In this case, radio waves or various switch signals sent by a portable device that replaces the key can be input to the vehicle system control unit 12020. The vehicle system control unit 12020 accepts such radio wave or signal inputs and controls the vehicle's door lock devices, power window devices, lights, etc.

[0227] The external information detection unit 12030 detects external information of the vehicle equipped with the vehicle control system 12000. For example, a camera unit 12031 is connected to the external information detection unit 12030. The external information detection unit 12030 causes the camera unit 12031 to capture images of the outside of the vehicle and receives the captured images. The external information detection unit 12030 can also perform object detection processing or distance detection processing based on the received images, such as people, vehicles, obstacles, signs, or text on the road surface.

[0228] The camera unit 12031 is a light sensor that receives light and outputs an electrical signal corresponding to the amount of light received. The camera unit 12031 can output the electrical signal as an image or as distance measurement information. Furthermore, the light received by the camera unit 12031 can be visible light or non-visible light such as infrared light.

[0229] The in-vehicle information detection unit 12040 detects information inside the vehicle. A driver status detection unit 12041, for example, detecting the driver's state, is connected to the in-vehicle information detection unit 12040. The driver status detection unit 12041 includes, for example, a camera that captures images of the driver. Based on the detection information input from the driver status detection unit 12041, the in-vehicle information detection unit 12040 can calculate the driver's fatigue level or level of concentration, and can also determine whether the driver is dozing off.

[0230] The microcomputer 12051 can calculate the control target values ​​of the drive force generating device, steering mechanism, or braking device based on the information obtained from the external information detection unit 12030 or the internal information detection unit 12040, and output control commands to the drive system control unit 12010. For example, the microcomputer 12051 can perform coordinated control for the purpose of realizing ADAS (Advanced Driver Assistance System) functions, including avoiding vehicle collisions or mitigating impacts, following the vehicle based on distance, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

[0231] Furthermore, the microcomputer 12051 can control the drive force generating device, steering mechanism or braking device, etc., based on the information about the vehicle's surroundings obtained by the external information detection unit 12030 or the internal information detection unit 12040, and perform coordinated control for the purpose of autonomous driving without relying on the driver's operation.

[0232] Furthermore, the microcomputer 12051 can output control commands to the vehicle system control unit 12020 based on the external information obtained by the external information detection unit 12030. For example, the microcomputer 12051 can control the headlights according to the position of the vehicle in front or oncoming vehicle detected by the external information detection unit 12030, and perform coordinated control such as switching the high beam to the low beam to achieve the purpose of anti-glare.

[0233] The audio-visual output unit 12052 transmits an output signal of at least one of the audio and visual signals to an output device that can provide visual or auditory notification information to the occupants of the vehicle or to the outside of the vehicle. In the example of FIG69, an amplifier 12061, a display unit 12062, and an instrument panel 12063 are shown as output devices. The display unit 12062 may also include at least one of, for example, an in-vehicle display and a head-up display.

[0234] Figure 70 is an example of the installation position of the camera unit 12031.

[0235] As shown in FIG70, the camera unit 12031 includes camera units 12101, 12102, 12103, 12104, and 12105.

[0236] Camera units 12101, 12102, 12103, 12104, and 12105 are installed in locations such as the front bumper, side mirrors, rear bumper, tailgate, and the upper part of the windshield inside the vehicle compartment of vehicle 12100. The camera unit 12101 installed in the front bumper and the camera unit 12105 installed on the upper part of the windshield inside the vehicle compartment primarily acquire images of the front of vehicle 12100. The cameras 12102 and 12103 installed in the side mirrors primarily acquire images of the sides of vehicle 12100. The camera unit 12104 installed in the rear bumper or tailgate primarily acquires images of the rear of vehicle 12100. The camera unit 12105 installed on the upper part of the windshield inside the vehicle compartment is mainly used to detect vehicles or pedestrians, obstacles, traffic lights, traffic signs, or lane markings ahead.

[0237] Additionally, Figure 70 shows an example of the camera range of camera units 12101 to 12104. Camera range 12111 represents the camera range of camera unit 12101 installed on the front bumper, camera ranges 12112 and 12113 represent the camera ranges of camera units 12102 and 12103 installed on the side mirrors, respectively, and camera range 12114 represents the camera range of camera unit 12104 installed on the rear bumper or tailgate. For example, by overlaying the image data captured by camera units 12101 to 12104, a top-down view of vehicle 12100 can be obtained.

[0238] At least one of the camera units 12101 to 12104 may also have the function of acquiring distance information. For example, at least one of the camera units 12101 to 12104 may be a stereo camera including a plurality of camera elements, or a camera element having pixels for phase difference detection.

[0239] For example, based on distance information obtained from cameras 12101 to 12104, microcomputer 12051 calculates the distances between itself and each three-dimensional object within the camera range 12111 to 12114, and the time variation of these distances (relative speed to vehicle 12100). This allows it to identify, in particular, the three-dimensional object closest to vehicle 12100 on its path and traveling at a specific speed (e.g., 0 km / h or higher) in a direction roughly the same as vehicle 12100, as the vehicle ahead. Furthermore, microcomputer 12051 can set a pre-defined distance to ensure proximity to the vehicle ahead, and perform automatic braking control (including follow-stop control) or automatic acceleration control (including follow-start control), etc. This allows for coordinated control aimed at autonomous driving, such as driving without driver input.

[0240] For example, based on the distance information obtained by the cameras 12101 to 12104, the microcomputer 12051 classifies and captures information related to three-dimensional objects into categories such as two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects for automatic obstacle avoidance. For example, the microcomputer 12051 can identify obstacles around the vehicle 12100 as obstacles visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Furthermore, the microcomputer 12051 determines the collision risk level, which indicates the degree of danger of colliding with each obstacle. When the collision risk level is above a set value and a collision is possible, the microcomputer 12051 outputs an alarm to the driver via the loudspeaker 12061 or the display unit 12062, or performs forced deceleration or evasive steering via the drive system control unit 12010, thereby providing driving assistance to avoid collisions.

[0241] At least one of the camera units 12101 to 12104 may also be an infrared camera that detects infrared light. For example, the microcomputer 12051 can identify a pedestrian by determining whether a pedestrian exists in the image captured by the camera units 12101 to 12104. The pedestrian identification is performed, for example, by capturing the order of feature points in the image captured by the camera units 12101 to 12104, which are infrared cameras, and by performing pattern matching processing on a series of feature points representing the outline of an object to determine whether it is a pedestrian. If the microcomputer 12051 determines that a pedestrian exists in the image captured by the camera units 12101 to 12104 and identifies the pedestrian, the audio-visual output unit 12052 controls the display unit 12062 to overlay and emphasize the square outline of the identified pedestrian. Furthermore, the audio-visual output unit 12052 can also control the display unit 12062 to display icons representing pedestrians at desired locations.

[0242] The above has described an example of a vehicle control system to which the technology disclosed herein can be applied. The technology disclosed herein can be applied to the camera unit 12031 in the configuration described above. Because by applying the technology disclosed herein to the camera unit 12031, higher-resolution camera images can be obtained, for example, the identification of obstacles or pedestrians in the camera images can be performed with higher accuracy. Furthermore, by applying the technology disclosed herein to the camera unit 12031, for example, more easily observable photographic images can be displayed, thereby reducing driver fatigue.

[0243] Although the preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings, the technical scope of the present disclosure is not limited to these examples. Those skilled in the art of the present disclosure will understand that various variations or modifications can be conceived within the scope of the technical ideas described in the claims, and these will naturally also fall within the technical scope of the present disclosure.

[0244] Furthermore, the effects described in this specification are for illustrative or exemplary purposes only and are not intended to limit. That is, the technology disclosed herein may be used in conjunction with or in place of the aforementioned effects to achieve other effects that are apparent to those skilled in the art from the description herein.

[0245] In addition, the following configurations also fall within the scope of the present disclosure. (1) An imaging device comprising: a semiconductor substrate, wherein an optical conversion unit is disposed on each of the two-dimensionally arranged pixels; a color filter disposed on the semiconductor substrate for each of the pixels; an intermediate layer disposed between the semiconductor substrate and the color filter; and a low-refractive-index region disposed between the pixels, wherein at least the color filter and the intermediate layer are separated for each of the pixels, and the refractive index is lower than that of the color filter. (2) The imaging device of (1) above, wherein the low-refractive-index region is composed of a gap. (3) The imaging device of (2) above, wherein at least a portion of the inner wall of the gap is covered by an insulating material. (4) The imaging device of any one of (1) to (3) above, further comprising a crystal lens disposed on the color filter. (5) The imaging device of (4) above, wherein the low-refractive region extends and is disposed on the side of the crystal lens, and the crystal lens is separated for each pixel. (6) The imaging device of any one of (1) to (5) above, further comprising a pixel separation wall disposed inside the semiconductor substrate, wherein the photoelectric conversion part is separated for each pixel by an insulating material. (7) The imaging device of (6) above, wherein the pixel separation wall is disposed through the semiconductor substrate. (8) The imaging device of (6) or (7) above, wherein the low-refractive region extends and is disposed inside the pixel separation wall. (9) The imaging device of (8) above, wherein the low-refractive region extends inside the pixel separation wall and is disposed through the semiconductor substrate. (10) The imaging device of (6) or (7) above, further comprising a light-shielding part disposed inside the pixel separation wall on the intermediate layer side. (11) The imaging device of (10) above, wherein the pixel separation wall is provided through the semiconductor substrate, and the light-shielding portion extends inside the pixel separation wall and is provided through the semiconductor substrate. (12) The imaging device of any one of (1) to (11) above, wherein the low-refractive region is provided throughout the entire circumference of the pixel. (13) The imaging device of any one of (1) to (12) above, wherein the pixel includes a phase difference pixel composed of a plurality of sub-pixels, and the low-refractive region is provided for each of the phase difference pixels. (14) The imaging device of (13) above, wherein a crystal lens is provided on the plurality of sub-pixels. (15) The imaging device of any one of (1) to (14) above, wherein the intermediate layer includes a layer having a negative fixed charge. (16) The imaging device of any one of (1) to (15) above, wherein the color filter includes a pigment or dye. (17) The imaging device of any one of (1) to (16) above, wherein the refractive index of the low refractive region is 1.35 or less.(18) The imaging device of (10) above, wherein the intermediate layer comprises a dielectric layer extending from the pixel separation wall along the bottom and side surfaces of the light-shielding portion and the lower surface of the color filter. (19) The imaging device of (18) above, wherein the intermediate layer further comprises a fixed charge layer having a negative fixed charge disposed between the dielectric layer and the semiconductor substrate. (20) The imaging device of (19) above, wherein the fixed charge layer extends along the dielectric layer and the side surface of the pixel separation wall. (21) The imaging device of (19) or (20) above, wherein the intermediate layer further comprises a reflection control layer disposed between the dielectric layer and the fixed charge layer, and having a refractive index higher than that of the dielectric layer and lower than that of the semiconductor substrate. (22) The imaging device of any one of (18) to (21) above, wherein the thickness of the dielectric layer disposed along the side of the light-shielding portion is the same as the thickness of the dielectric layer disposed along the lower surface of the light-shielding portion. (23) The imaging device of (22) above, wherein the thickness of the dielectric layer disposed along the lower surface of the color filter is the same as the thickness of the dielectric layer disposed along the side and lower surface of the light-shielding portion. (24) The imaging device of any one of (18) to (21) above, wherein the thickness of the dielectric layer disposed along the side of the light-shielding portion is thinner than the thickness of the dielectric layer disposed along the lower surface of the light-shielding portion. (25) The imaging device of any one of (18) to (24) above, wherein the width of the light-shielding portion is the same as or narrower than the width of the low-refractive region. (26) The imaging device of any one of (18) to (25) above, wherein the light-shielding portion and the low-refractive region are disposed in a manner that they do not contact each other. (27) The imaging device of any one of (18) to (26) above, wherein the height of the upper surface of the light-shielding portion is the same as the height of the upper surface of the semiconductor substrate. (28) The imaging device of any one of (18) to (26) above, wherein the lower surface position of the light-shielding portion disposed between the pixels in the diagonal direction of the pixels is lower than the lower surface position of the light-shielding portion disposed between the pixels in the pixel arrangement direction. (29) The imaging device of (28) above, wherein the width of the light-shielding portion disposed between the pixels in the diagonal direction of the pixels is wider than the width of the light-shielding portion disposed between the pixels in the pixel arrangement direction. [Simplified Explanation of the Diagram]

[0010] Figure 1 is a schematic diagram showing the overall structure of the imaging device according to one embodiment of the present disclosure. Figure 2 is a longitudinal sectional view showing the cross-sectional structure of the pixel section of this embodiment. Figure 3 is a longitudinal sectional view showing variations in the cross-sectional shape of the gap constituting the low-refractive region. Figure 4A is a top view showing an example of the planar structure of the pixel section. Figure 4B is a top view showing an example of the planar structure of the pixel section. Figure 4C is a top view showing an example of the planar structure of the pixel section. Figure 5 is a longitudinal sectional view showing the cross-sectional structure of the pixel section in a first variation. Figure 6 is a longitudinal sectional view showing the cross-sectional structure of the pixel section in a second variation. Figure 7 is a longitudinal sectional view showing the cross-sectional structure of the pixel section in a third variation. Figure 8 is a longitudinal sectional view showing the cross-sectional structure of the pixel section in a fourth variation. Figure 9 is a longitudinal sectional view showing the cross-sectional structure of the pixel section in a fifth variation. Figure 10 is a longitudinal sectional view showing the cross-sectional structure of the pixel section in a sixth variation. Figure 11 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 7th variation. Figure 12 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 8th variation. Figure 13 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 9th variation. Figure 14 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 10th variation. Figure 15 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 11th variation. Figure 16 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 12th variation. Figure 17 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 13th variation. Figure 18 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 14th variation. Figure 19 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 15th variation. Figure 20 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 16th variation. Figure 21 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the 17th variation. Figure 22 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section in the 18th variation example. Figure 23 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section in the 19th variation example. Figure 24 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section in the 20th variation example. Figure 25 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section in the 21st variation example. Figure 26 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section in the 22nd variation example. Figure 27 is a longitudinal sectional view showing the cross-sectional configuration of the pixel section in the 23rd variation example. Figure 28A is a top view showing an example of a planar configuration when phase difference pixels and normal pixels coexist. Figure 28B is a top view showing an example of a planar configuration when phase difference pixels and normal pixels coexist. Figure 28C is a top view showing an example of a planar configuration when phase difference pixels and normal pixels coexist. Figure 29A is a top view showing an example of a planar configuration with only phase difference pixels. Figure 29B is a top view showing an example of a planar configuration with only phase difference pixels. Figure 29C is a top view showing an example of a planar configuration with only phase difference pixels.Figure 30 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion in the second embodiment of this disclosure. Figure 31 is an enlarged longitudinal sectional view of the area near the light-shielding portion in Figure 30. Figure 32A is a longitudinal sectional view showing a change in the configuration near the light-shielding portion in the first variation. Figure 32B is a longitudinal sectional view showing a change in the configuration near the light-shielding portion in the first variation. Figure 32C is a longitudinal sectional view showing a change in the configuration near the light-shielding portion in the first variation. Figure 32D is a longitudinal sectional view showing a change in the configuration near the light-shielding portion in the first variation. Figure 32E is a longitudinal sectional view showing a change in the configuration near the light-shielding portion in the first variation. Figure 32F is a longitudinal sectional view showing a change in the configuration near the light-shielding portion in the first variation. Figure 33 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion in the second variation. Figure 34 is a longitudinal sectional view showing the cross-sectional configuration of the pixel portion in the third variation. Figure 35 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the fourth variation. Figure 36 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the fifth variation. Figure 37 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the sixth variation. Figure 38 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the seventh variation. Figure 39 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the eighth variation. Figure 40 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the eighth variation. Figure 41 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the eighth variation. Figure 42 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the ninth variation. Figure 43 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the tenth variation. Figure 44 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the eleventh variation. Figure 45 is a longitudinal sectional view showing the cross-sectional structure of the pixel portion in the twelfth variation. Figure 46 is a longitudinal sectional view showing the cross-sectional configuration of the pixel unit in the 13th variation example. Figure 47 is a longitudinal sectional view showing the cross-sectional configuration of the pixel unit in the 14th variation example. Figure 48A is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48B is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48C is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48D is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48E is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48F is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48G is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48H is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 48I is a top view showing an example of the planar arrangement of the color filters in the pixel unit. Figure 49A is a top view showing an example of a combination of a color filter and ordinary pixels or phase difference pixels. Figure 49B is a top view showing an example of a combination of a color filter and ordinary pixels or phase difference pixels.Figure 49C is a top view showing an example of a combination of a color filter and a normal pixel or a phase-difference pixel. Figure 49D is a top view showing an example of a combination of a color filter and a normal pixel or a phase-difference pixel. Figure 49E is a top view showing an example of a combination of a color filter and a normal pixel or a phase-difference pixel. Figure 49F is a top view showing an example of a combination of a color filter and a normal pixel or a phase-difference pixel. Figure 50 is a top view illustrating the structure of the pixel section in the 15th variation example. Figure 51 is a longitudinal sectional view showing a comparison between the cross-sectional structure along line A-AA and the cross-sectional structure along line B-BB in Figure 50. Figure 52 is a longitudinal sectional view illustrating the steps of forming the pixel section in the 15th variation example. Figure 53 is a longitudinal sectional view illustrating the steps of forming the pixel section in the 15th variation example. Figure 54 is a longitudinal sectional view illustrating the steps of forming the pixel section in the 15th variation example. Figure 55 is a longitudinal sectional view illustrating the steps of forming the pixel section in the 15th variation example. Figure 56 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 57 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 59 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 60 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 61 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 62 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 63 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 64 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 15th variation example. Figure 65 is a longitudinal sectional view showing the structure near the light-shielding portion of the pixel portion in the 16th variation example. Figure 66 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 16th variation example. Figure 67 is a longitudinal sectional view illustrating the steps of forming the pixel portion in the 16th variation example. Figure 68 is a block diagram showing an example of the configuration of an electronic device including one embodiment of the present disclosure. Figure 69 is a block diagram showing an example of the schematic configuration of a vehicle control system. Figure 70 is an explanatory diagram showing an example of the installation positions of the vehicle exterior information detection unit and the camera unit.

Claims

1. An imaging device comprising: a semiconductor substrate having a photoelectric conversion unit disposed on each of the two-dimensionally arranged pixels; a color filter, in cross-section, disposed on the light incident surface side of the semiconductor substrate for each of the pixels; an intermediate layer disposed between the semiconductor substrate and the color filter; a low-refractive-index region disposed between the color filter and having a refractive index lower than that of the color filter and the intermediate layer; and an insulating layer, in cross-section, surrounding the low-refractive-index region and sealing the upper end of the low-refractive-index region; and having a recessed structure formed in the intermediate layer.

2. The imaging device of claim 1, wherein the aforementioned low-refractive region is composed of voids.

3. The camera device of claim 2, wherein at least a portion of the inner wall of the aforementioned gap is covered with an insulating material.

4. The imaging device of claim 1 further includes a crystal lens disposed on the aforementioned color filter.

5. The imaging device of claim 4, wherein the low-refractive region extends to the side of the crystal lens, and the crystal lens is separated for each pixel.

6. The imaging device of claim 1 further includes a pixel separation wall disposed inside the semiconductor substrate, which separates the photoelectric conversion part of each pixel by an insulating material.

7. The camera device of claim 6, wherein the pixel separation wall is provided through the semiconductor substrate.

8. The camera device of claim 6, wherein the aforementioned low-refractive region extends into the interior of the aforementioned pixel separation wall.

9. The imaging device of claim 8, wherein the low-refractive region extends inside the pixel separation wall and penetrates the semiconductor substrate.

10. The camera device of claim 1 further includes a light-shielding portion on the light incident surface side of the aforementioned intermediate layer side.

11. The imaging apparatus of claim 10, wherein the pixel separation wall is disposed through the semiconductor substrate, and the light-shielding portion extends inside the pixel separation wall and is disposed through the semiconductor substrate.

12. The imaging device of claim 1, wherein the aforementioned low-refractive region is provided throughout the entire circumference of the aforementioned pixels.

13. The imaging device of claim 1, wherein the pixel comprises a phase difference pixel consisting of a plurality of sub-pixels, and the low refractive region is provided according to each of the phase difference pixels.

14. The imaging device of claim 13, wherein a crystal lens is provided above the plurality of sub-pixels.

15. The imaging device of claim 1, wherein the intermediate layer comprises a layer having a negative fixed charge.

16. The camera device of claim 1, wherein the color filter comprises pigment or dye.

17. The imaging device of claim 1, wherein the refractive index of the aforementioned low-refractive region is 1.35 or less.

18. The imaging apparatus of claim 10, wherein the intermediate layer comprises a dielectric layer extending from the pixel separation wall along the bottom and side surfaces of the light-shielding portion and the lower surface of the color filter.

19. The imaging apparatus of claim 18, wherein the intermediate layer further comprises a fixed charge layer having a negative fixed charge disposed between the dielectric layer and the semiconductor substrate.

20. The imaging apparatus of claim 19, wherein the fixed charge layer extends along the side of the dielectric layer and the pixel separation wall.

21. The imaging apparatus of claim 19, wherein the intermediate layer further includes a reflection control layer disposed between the dielectric layer and the fixed charge layer, and has a refractive index higher than that of the dielectric layer and lower than that of the semiconductor substrate.

22. The imaging device of claim 18, wherein the thickness of the dielectric layer disposed along the side of the light-shielding portion is the same as the thickness of the dielectric layer disposed along the lower surface of the light-shielding portion.

23. The imaging apparatus of claim 22, wherein the thickness of the dielectric layer disposed along the lower surface of the color filter is the same as the thickness of the dielectric layer disposed along the side and lower surface of the light-shielding portion.

24. The imaging device of claim 18, wherein the thickness of the dielectric layer disposed along the side of the light-shielding portion is thinner than the thickness of the dielectric layer disposed along the lower surface of the light-shielding portion.

25. The imaging device of claim 18, wherein the width of the light-shielding portion is the same as or narrower than the width of the low-refractive region.

26. The camera device of claim 18, wherein the light-shielding part and the low-refractive area are arranged in a manner that they do not come into contact with each other.

27. The imaging device of claim 18, wherein the height of the upper surface of the light-shielding portion is the same as the height of the upper surface of the semiconductor substrate.

28. The imaging device of claim 18, wherein the position of the lower surface of the light-shielding portion disposed between the pixels in the diagonal direction of the pixels is lower than the position of the lower surface of the light-shielding portion disposed between the pixels in the arrangement direction of the pixels.

29. The imaging device of claim 28, wherein the width of the light-shielding portion disposed between the pixels in the diagonal direction of the pixels is wider than the width of the light-shielding portion disposed between the pixels in the arrangement direction of the pixels.

Images