Light detection device and electronic apparatus

Abstract

The present technology relates to a light detection device and an electronic apparatus capable of improving the reliability of a light collection design. A light detection device according to one aspect of the present technology includes a semiconductor substrate having a photoelectric conversion unit, a spacer layer disposed on the semiconductor substrate, a metasurface layer disposed on the spacer layer, and a sidewall protection film disposed at least on a sidewall of the spacer layer. The present technology is applicable to an image sensor including a metasurface layer.

Description

Technical Field

[0001] The present technology relates to a light detection device and an electronic device, and in particular to a light detection device and an electronic device capable of improving the reliability of a light focusing design. Background Art

[0002] In recent years, a light detection device having a color separation lens array as an optical element composed of a plurality of fine structures has been proposed (for example, see Patent Document 1). A color separation lens array that separates incident light by wavelength and focuses the incident light on light sensing units of each color is also called a metasurface element. Citation list Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2021-069119 Summary of the invention Technical problem to be solved by the invention

[0004] As a reliability test of the optical detection device having the above structure, a heat resistance test is usually performed. When the material expands in this heat resistance test, an offset occurs between the layer of the optical element composed of multiple fine structures (supersurface layer) and the transparent layer (spacer layer) arranged below the supersurface layer. The offset between the supersurface layer and the spacer layer will reduce the reliability of the focusing design.

[0005] The present technology has been developed in view of the above circumstances and is intended to improve the reliability of the light concentrating design. Solutions to technical problems

[0006] According to one aspect of the present technology, a light detecting device is a light detecting device comprising: a semiconductor substrate including a photoelectric conversion unit; a spacer layer arranged on the semiconductor substrate; a supersurface layer arranged on the spacer layer; and a sidewall protection film arranged at least on the sidewall of the spacer layer.

[0007] According to another aspect of the present technology, an electronic device is an electronic device comprising a semiconductor substrate, which includes a photoelectric conversion unit; a spacer layer arranged on the semiconductor substrate; a super surface layer arranged on the spacer layer and a sidewall protection film arranged at least on the sidewall of the spacer wall. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 : is a block diagram showing a configuration example of a light detection device according to one embodiment of the present technology. Figure 2 is a cross-sectional view near an end portion of the CMOS image sensor according to the first embodiment. Figure 3This is an enlarged view of the vicinity of the side wall protection film according to the first embodiment. Figure 4 It is a diagram showing the installation range of the side wall protection film according to the first embodiment. Figure 5 1 is a diagram showing changes in the state of each component during a reliability test of a CMOS image sensor not provided with a sidewall protection film. Figure 6 It is a diagram showing another effect of the first embodiment. Figure 7 It is a diagram showing a cross-sectional structure of a first modified example of the first embodiment. Figure 8 It is a diagram showing a cross-sectional structure of a second modified example of the first embodiment. Fig. 9 is a cross-sectional view near an end portion of a CMOS image sensor according to a second embodiment. Fig.10 It is a diagram showing the effect of the second embodiment. Fig.11 : is a diagram showing a first method of manufacturing the CMOS image sensor according to the first embodiment. Fig.12 : is a diagram showing a first method of manufacturing the CMOS image sensor according to the first embodiment. Fig.13 : is a diagram showing a first method of manufacturing the CMOS image sensor according to the first embodiment. Fig.14 : is a diagram showing a second method of manufacturing the CMOS image sensor according to the first embodiment. Fig.15 is a diagram illustrating a second method of manufacturing the CMOS image sensor according to the first embodiment. Fig.16 : is a diagram showing a second method of manufacturing the CMOS image sensor according to the first embodiment. Fig.17 : is a diagram showing a first method of manufacturing the CMOS image sensor according to the second embodiment. Fig.18 : is a diagram showing a second method of manufacturing the CMOS image sensor according to the second embodiment. Fig.19 This is a block diagram showing a configuration example of an imaging device as an electronic device to which the present technology is applied. Fig. 20 This is a diagram showing an example of use of a CMOS image sensor. DETAILED DESCRIPTION

[0009] The following will describe a mode for implementing the present technology. The description will be made in the following order. 1. First Embodiment (Example of a Case Where a Side Wall Protective Film is Provided) 2. Second Embodiment (Example of a Case Where a Light-Shielding Film is Provided) 3. Manufacturing method of the first embodiment 4. Manufacturing method of the second embodiment 5. Application examples in electronic devices 6. Examples of use of light detection devices 7. Others

[0010] <<1. First Embodiment (Example of a Case Where a Side Wall Protective Film is Provided)>> <Overall Structure of Photodetection Device> Figure 1 : is a block diagram showing a configuration example of a light detection device according to one embodiment of the present technology.

[0011] The light detection device according to an embodiment of the present technology is, for example, a complementary metal oxide semiconductor (CMOS) image sensor 1 .

[0012] The CMOS image sensor 1 includes, for example, a pixel array unit 11 , a vertical driving unit 12 , a column processing unit 13 , a horizontal driving unit 14 , a system control unit 15 , a signal processing unit 18 , and a data storage unit 19 .

[0013] The pixel array unit 11 is configured by arranging a plurality of pixels having a photoelectric conversion unit in an array. The photoelectric conversion unit is a semiconductor region that generates charges corresponding to the amount of incident light. The pixels are arranged in the horizontal direction (row direction) and the vertical direction (column direction).

[0014] The vertical driving unit 12 includes, for example, a shift register, an address decoder, etc., and drives the pixels of the pixel array unit 11 row by row via a plurality of pixel driving lines 16. The driving method is not limited to the row by row driving method, and for example, there is also a method of driving all pixels simultaneously.

[0015] The pixel signals output from the pixels driven by the vertical driving unit 12 are supplied to the column processing unit 13 through a plurality of corresponding vertical signal lines 17. The column processing unit 13 performs noise removal processing, correlated double sampling processing, analog-to-digital (AD) conversion processing, etc., and generates digital pixel signals. The column processing unit 13 supplies the generated pixel signals to the signal processing unit 18.

[0016] The horizontal driving unit 14 includes, for example, a shift register, an address decoder, etc., and selects and drives each circuit of the column processing unit 13. The circuit of the column processing unit 13 selected by the horizontal driving unit 14 supplies the generated pixel signal to the signal processing unit 18.

[0017] The system control unit 15 includes, for example, a timing generator, etc. The timing generator is a circuit that generates various timing signals. The system control unit 15 performs drive control of the vertical drive unit 12, the column processing unit 13, and the horizontal drive unit 14 based on the timing signals generated by the timing generator.

[0018] The signal processing unit 18 performs arithmetic processing on each pixel signal supplied from the column processing unit 13 .

[0019] The data storage unit 19 temporarily stores data necessary for arithmetic processing by the signal processing unit 18 .

[0020] <Structure of Photodetection Device> Figure 2 is a cross-sectional view near an end portion of the CMOS image sensor 1 according to the first embodiment. Figure 2 The left direction in φ is the center direction of the CMOS image sensor 1 .

[0021] The CMOS image sensor 1 basically has a configuration in which a semiconductor substrate 51 , a spacer layer 53 , and a super-surface layer 55 are stacked.

[0022] The semiconductor substrate 51 is, for example, a silicon substrate. The semiconductor substrate 51 includes a plurality of photoelectric conversion units (photodiodes). Each pixel is composed of a photoelectric conversion unit included in the semiconductor substrate 51. The material of the semiconductor substrate 51 is not limited to silicon, and may be, for example, germanium, a compound semiconductor material, an organic semiconductor material, or the like.

[0023] The semiconductor substrate 51 has a first surface as a surface on the light incident side and a second surface as a surface opposite to the first surface. A multilayer wiring layer not shown is provided below the second surface (in the downward direction in the figure). Figure 2 The illustrated CMOS image sensor 1 is a so-called back-illuminated CMOS image sensor.

[0024] The color filter 52 is disposed on the upper part of the semiconductor substrate 51 (upward direction in the figure). A plurality of insulating films may be disposed between the semiconductor substrate 51 and the color filter 52. The color filter 52 transmits light of a wavelength band of a corresponding color. The light transmitted through the color filter 52 reaches a photoelectric conversion unit disposed in the semiconductor substrate 51.

[0025] Figure 2 The structure of the color filter 52 shown in FIG. 1 shows the red, green and blue color filters in sequence from left to right. Figure 2 In the example of , the color filters 52 of three colors of red, green and blue are shown, but the colors are not limited. In addition, in the case where the super surface layer 55 has a function equivalent to that of the color filter 52, the color filter 52 may not be provided.

[0026] The spacer layer 53 is disposed on the upper portion of the semiconductor substrate 51 . The material of the spacer layer 53 is, for example, an organic material. The organic material is a transparent resin that transmits incident light. The material of the spacer layer 53 may be different from the material of the super surface layer 55 .

[0027] As a material of the spacer layer 53, an inorganic material may be used instead of an organic material. The inorganic material is preferably a material that transmits incident light, and is, for example, silicon oxide or silicon oxynitride. The spacer layer 53 may be composed of an organic material and an inorganic material. That is, the spacer layer 53 may be composed of at least one of an organic material or an inorganic material. The spacer layer 53 is configured to flatten the upper portion of the semiconductor substrate 51.

[0028] The first anti-reflection film 54 is disposed on the upper portion of the spacer layer 53. The material of the first anti-reflection film is, for example, silicon nitride. The first anti-reflection film 54 is configured to suppress reflection generated at the interface between the spacer layer 53 and the super surface layer 55. In addition, when forming the fine structure 55a of the super surface layer 55, the first anti-reflection film 54 also serves as an etching stop layer. In addition, the first anti-reflection film 54 may not be provided.

[0029] The super surface layer 55 is arranged on the upper part of the spacer layer 53 across the first anti-reflection film 54. The super surface layer 55 has various optical functions. Specifically, there are color separation functions (color separators) for controlling the propagation direction of light in each wavelength band, functions (lenses) for converging light in a specific wavelength band, polarization separation functions for separating light in a specific polarization direction, and wavelength selection functions (filters) for transmitting only light in a specific wavelength band, etc. In the present technology, the functions of the super surface layer 55 are not limited to the specific functions of the above functions. The super surface layer 55 having these functions can be referred to as an advanced surface layer, an optical functional layer, an optical control layer, a color separator layer, a color separation layer, a light deflection layer, etc.

[0030] The super surface layer 55 is composed of at least a fine structure body 55a and a transparent layer 55b. The fine structure body 55a is formed at a position corresponding to the position of the color filter of each color in the transparent layer 55b.

[0031] The first material used as the material of the fine structure 55a has a higher refractive index than the second material used as the material of the transparent layer 55b. The first material is, for example, titanium oxide. More specifically, the first material can be selected from silicon, silicon nitride, silicon carbide, tantalum oxide, niobium oxide, hafnium oxide, indium oxide, tin oxide, siloxane, etc. Figure 2 , the structure of the fine structure 55a is shown as a columnar structure (pillar structure), but is not limited to the columnar structure.

[0032] The refractive index of the second material of the transparent layer 55b is lower than the refractive index of the first material of the fine structure 55a. The second material may be selected from, for example, silicon oxide, silicon nitride, and the like.

[0033] The second anti-reflection film 56 is disposed on the upper portion of the supersurface layer 55. The material of the second anti-reflection film is, for example, silicon nitride. The second anti-reflection film 56 is configured to suppress reflection generated at the interface between the supersurface layer 55 and the layer disposed on the upper portion of the supersurface layer 55. The second anti-reflection film 56 may be composed of a plurality of films.

[0034] like Figure 2 As shown, a groove (recess) 58 reaching the front surface of the semiconductor substrate 51 from the front surface of the CMOS image sensor 1 is formed at a position closer to the end of the CMOS image sensor 1 having the above-mentioned layer structure, and a side wall protection film 57 is provided to constitute the inner wall of the groove 58. The side wall protection film 57 is formed integrally with the super surface layer 55 so that, for example, the end of the super surface layer 55 (transparent layer 55b) extends downward.

[0035] The side wall protection film 57 constitutes the inner wall of the groove 58 and is provided on the side wall of the spacer layer 53 ( Figure 3 As described later, the side wall protection film 57 is provided as a film that protects at least the side wall of the spacer layer 53. The side wall protection film 57 has a function of preventing the spacer layer 53 from swelling in a reliability test and a function of preventing moisture from entering the light detection device from the outside.

[0036] The material of the side wall protection film 57 is, for example, an inorganic material. More specifically, for example, silicon oxide, silicon nitride, etc. can be selected. The material of the side wall protection film 57 can be the same as any one of the material of the first anti-reflection film 54, the first material of the fine structure 55a, the second material of the transparent layer 55b, and the material of the second anti-reflection film 56. In addition, the side wall protection film 57 can be composed of a plurality of films.

[0037] For example, at a position outside the side wall protection film 57 (in the right direction in the figure), a pad opening 59 is provided as a groove (recess) penetrating from the front surface of the CMOS image sensor 1 to the back surface of the semiconductor substrate 51. A metal electrode not shown is provided at the bottom of the pad opening 59. Wiring for connecting the metal electrode to an external power supply or the like is provided in the pad opening 59.

[0038] Figure 3 yes Figure 2 An enlarged view of the vicinity of the side wall protection film 57.

[0039] The side wall protection film 57 constitutes the inner wall of the groove 58 disposed outside the pixel region (effective pixel region) that receives incident light and generates image signals. The side wall protection film 57 is formed integrally with, for example, the transparent layer 55b by a manufacturing method described later. As a result, the side wall protection film 57 is provided to constitute the side wall of the super surface layer 55.

[0040] The thickness T of the sidewall protection film 57 may be 10 nm to 5000 nm. The width W of the groove 58 is 10 nm or more according to the thickness T. The width (height) w of the sidewall protection film 57 in the height direction of the CMOS image sensor 1 is higher than the height of the spacer 53 .

[0041] Figure 4 2 is a diagram showing the installation range of the side wall protection film 57 . Figure 4 The left side of FIG. 1 shows the configuration of the CMOS image sensor 1 in a plan view, and the right side shows the configuration of a cross section at a portion of a dotted line AA.

[0042] As in Figure 4 As shown on the left side of FIG. , the side wall protection film 57 is provided to surround the periphery of the effective pixel area which is a rectangular area. Figure 4 In the example of FIG. 5 , a narrow optical black region is formed outside the effective pixel region, and a side wall protection film 57 is provided around the optical black region. With such a configuration, deformation of the spacer layer 53 can be more effectively suppressed.

[0043] <Effect of Side Wall Protective Film> Figure 5 1 is a diagram showing changes in the state of each member during a reliability test of a CMOS image sensor not provided with the sidewall protection film 57 .

[0044] exist Figure 5 , the configurations corresponding to the above-described configurations of the CMOS image sensor 1 according to one embodiment of the present technology are denoted by the same reference numerals. Reliability testing is a general term for various tests performed, for example, before product shipment in order to test the reliability of a product. Examples of reliability testing include heat resistance testing and weather resistance testing.

[0045] Figure 5 A is a diagram showing the state of the CMOS image sensor before the reliability test (at room temperature). As shown by the hollow arrow, the force of expansion in the in-plane direction (left-right direction in the figure) acts on the super surface layer 55 made of inorganic material. On the other hand, the spacer layer 53 made of, for example, an organic material is hard at room temperature. The expansion of the super surface layer 55 is suppressed by the spacer layer 53, and as a result, the super surface layer 55 is in a state that cannot expand.

[0046] Figure 5 B is a diagram showing the state of the CMOS image sensor during the reliability test (at high temperature). At high temperature, the spacer layer 53 made of organic material deforms (creeps). The spacer layer 53 cannot suppress the expansion of the super surface layer 55, and as a result, the super surface layer 55 is in a state that can expand in the in-plane direction.

[0047] Figure 5FIG. C is a diagram showing the state of the CMOS image sensor after the reliability test (at room temperature). Due to the expansion during the reliability test, an offset occurs between the super surface layer 55 and the spacer layer 53. Figure 5 In the example of C, the position of the fine structure 55a is shifted to the right from the position before the reliability test. Due to the position shift of the fine structure 55a, the reliability of the light focusing design of the CMOS image sensor 1 is reduced.

[0048] According to the first embodiment, the spacer layer 53 can be prevented from being deformed during the reliability test by providing the sidewall protection film 57 at least on the sidewall of the spacer layer 53. By preventing the deformation of the spacer layer 53, the offset between the super surface layer 55 and the spacer layer 53 can be prevented, and as a result, the reliability of the focusing design of the CMOS image sensor 1 can be improved.

[0049] exist Figure 5 In the embodiment, the case where the spacer layer 53 is made of an organic material has been described. On the other hand, even in the case where the spacer layer 53 is made of an inorganic material, there is a possibility that an offset may occur between the super surface layer 55 and the spacer layer 53 during the reliability test. According to the first embodiment, even in the case where the spacer layer 53 is made of an inorganic material, the reliability of the light focusing design of the CMOS image sensor 1 can be improved.

[0050] In the case of an ordinary CMOS image sensor that does not include the metasurface layer 55, an on-chip lens is provided as an optical element. The on-chip lens is made of an organic material, and as a composition of an inorganic material, only a film thinner than the metasurface layer 55 is provided between the on-chip lens and the semiconductor substrate. Therefore, in the reliability test of an ordinary CMOS image sensor, Figure 5 A deviation from the specification will hardly occur.

[0051] On the other hand, in the case of reliability testing of a CMOS image sensor having a supersurface layer 55 made of a thick inorganic material, Figure 5 By providing a sidewall protection film 57 to form the sidewalls of the spacer layer 53 and the super surface layer 55, such a deviation can be prevented from occurring.

[0052] Figure 6 2 is a diagram showing another effect of the first embodiment.

[0053] like Figure 6 As shown by the thick arrow in FIG. 5 , by providing the side wall protection film 57 on the side wall of the spacer layer 53, it is possible to prevent moisture from entering the CMOS image sensor 1 from the side wall of the spacer layer 53. This also makes it possible to improve the reliability of the CMOS image sensor 1.

[0054] <Modification of the First Embodiment> - First variant Figure 7 1 is a diagram showing a cross-sectional structure of a first modification example of the first embodiment.

[0055] exist Figure 7 In the example of FIG. 5 , the sidewall protection film 57 is disposed on the sidewall of the spacer layer 53 , but not on a portion of the super surface layer 55 . The height of the sidewall protection film 57 is substantially the same as that of the spacer layer 53 .

[0056] In this manner, the side wall protection film 57 is provided at least on the side wall of the spacer layer 53. It is desirable that the height of the side wall protection film 57 is equal to or higher than the height of the spacer layer 53. The effects of the first modification example are the same as those of the first embodiment.

[0057] - Second variant Figure 8 It is a diagram showing a cross-sectional structure of a second modified example of the first embodiment.

[0058] exist Figure 8 In the example of , the side wall protection film 57 is provided to fill the groove 58. Figure 8 In the example of the present invention, the groove 58 is made of the same material as the material of the transparent layer 55b, but the material is not limited thereto. The groove 58 may be filled with a variety of materials. In addition, there may be a gap (air gap) inside the groove 58 filled with the sidewall protection film 57. The effect of the second modification example is the same as that of the first embodiment.

[0059] <<2. Second Embodiment (Example of a Case Where a Light Shielding Film is Provided)>> Fig. 9 2 is a cross-sectional view near an end portion of a CMOS image sensor 1 according to a second embodiment. Fig. 9 In, with Figure 2 The corresponding structures in the figure are represented by the same figure marks, and their descriptions will be appropriately omitted.

[0060] A light shielding film 61 is provided in the groove 58 of the CMOS image sensor 1 according to the second embodiment. The light shielding film 61 is composed of, for example, a first portion 61a and a second portion 61b. The first portion 61a is provided to cover the side wall protection film 57. In other words, the wall surface composed of the side wall protection film 57 is provided adjacent to the wall surface composed of the first portion 61a. More specifically, the first portion 61a is provided to fill the groove 58. Figure 2 The second portion 61b is disposed on the upper portion of the super surface layer 55. For example, the second portion 61b is disposed to cover the upper portion of the optical black region, but not the upper portion of the effective pixel region.

[0061] The material of the light shielding film 61 is, for example, a metal material. More specifically, the material of the light shielding film 61 is selected from pure metals or alloy materials such as tungsten (W), aluminum (Al) or copper (Cu). In addition, the material of the light shielding film 61 may be an organic material such as a black resist.

[0062] Fig.10 2 is a diagram showing the effects of the second embodiment.

[0063] Fig.10 A is a diagram showing the path of external light of a CMOS image sensor in which a light-shielding film 61 is not provided. In a CMOS image sensor having a supersurface layer 55, a spacer layer 53 having a thickness of about several μm is provided. As a result, the CMOS image sensor is susceptible to light (external light) incident obliquely from the outside. In the absence of a light-shielding film 61, as shown by a thick solid arrow, external light is reflected by the front surface of the semiconductor substrate 51, etc., and is incident on the supersurface layer 55. The external light is bent by the supersurface layer 55 in an unexpected direction, thereby generating flare.

[0064] Fig.10 B is a diagram showing the path of external light of the CMOS image sensor 1 according to the second embodiment. According to the second embodiment, the incident external light is absorbed by the light shielding film 61 as shown by the thick solid arrow. Therefore, the external light can be prevented from being bent in an unintended direction in the super surface layer 55, so that the occurrence of flare can be suppressed.

[0065] exist Fig. 9 and Fig.10 In the embodiment, it is assumed that the light shielding film 61 is composed of the first portion 61a and the second portion 61b, but the configuration of the light shielding film 61 is not limited to the configuration shown. For example, the second portion 61b of the light shielding film 61 may be provided at Figure 8 In the configuration of. In addition, only the first portion 61a may be provided without providing the second portion 61b. In addition, another film (not shown) may be provided between the first portion 61a and the second portion 61b.

[0066] <<3. Manufacturing method of first embodiment>> - First manufacturing method Will refer to Figures 11 to 13 A first method of manufacturing the CMOS image sensor 1 according to the first embodiment is described.

[0067] First, if Fig.11 As shown in the process of step S1 in FIG. 1 , a color filter 52 is formed on the upper part of the semiconductor substrate 51. In the process of step S1, a light shielding wall composed of, for example, a dielectric is formed between the color filters 52. In addition, a light shielding film 101 constituting an optical black area is formed outside the effective pixel area.

[0068] Next, if Fig.11 As shown in the process of step S2 in FIG. 1 , a spacer layer 53 is formed on the upper part of the semiconductor substrate 51. The spacer layer 53 can be formed by various physical or chemical film forming methods. Specifically, the film forming method includes a physical vapor deposition (PVD) method, a chemical vapor deposition (CVD) method, and an atomic layer deposition (ALD) method.

[0069] Next, if Fig.11 As shown in the process of step S3 in FIG. 5 , a groove 58 and a pad opening 59 for forming the side wall protection film 57 are formed. For example, the groove 58 and the pad opening 59 are formed using anisotropic dry etching.

[0070] Next, if Fig.12 As shown in the process of step S4 in the above, the first anti-reflection film 54 and the transparent layer 55b of the super surface layer 55 are formed. The first anti-reflection film 54 and the transparent layer 55b can be formed by the above-mentioned physical or chemical film forming method. Fig.12 In the example of , not only a film of the same material as the material of the transparent layer 55b is formed inside the groove 58, but also a first anti-reflection film 54 is formed. The material of the sidewall protection film 57 includes two materials, that is, the material of the first anti-reflection film 54 and the material of the same material as the transparent layer 55b. As described above, the sidewall protection film 57 may include a plurality of films. During step S4, at least one of the first anti-reflection film 54 and the transparent layer 55b is formed as the sidewall protection film 57 to constitute the sidewall of the spacer layer 53.

[0071] Next, if Fig.12 As shown in the process of step S5 in FIG. 1 , a hard mask 102 is formed on the transparent layer 55b. The hard mask 102 is formed to have a structure in which silicon oxide and amorphous silicon are stacked, for example.

[0072] Next, if Fig.12 As shown in the process of step S6 in FIG. 1 , a resist mask 103 having a predetermined planar layout pattern is formed. The resist mask 103 is formed using a known photolithography technique. The planar layout pattern of the resist mask 103 defines the pattern of the fine structure 55 a of the super surface layer 55 .

[0073] Next, if Fig.13 As shown in the process of step S7 in , the transparent layer 55b is dry-etched. In this process, dry etching is performed under etching conditions with selectivity. The first anti-reflection film 54 also serves as an etching stopper. After etching, the resist mask 103 is removed.

[0074] Next, if Fig.13As shown in the process of step S8 in the above, a fine structure 55a of the super surface layer 55 is formed. The fine structure 55a is formed by filling the pattern formed in the process of step S7 with titanium oxide, etc. using, for example, an ALD method. After the fine structure 55a is formed, the film formed on the upper part of the transparent layer 55b and the front surface of the side wall protection film 57 is removed.

[0075] Next, if Fig.13 As shown in the process of step S9 in the embodiment, the second anti-reflection film 56 is formed. The second anti-reflection film 56 can be formed by the various film forming methods described above. In the process of step S9, the second anti-reflection film 56 can also be formed inside the groove 58. In this case, the second anti-reflection film 56, the first anti-reflection film 54, and the film of the same material as the transparent layer 55b together constitute the side wall of the spacer layer 53 as the side wall protection film 57.

[0076] - Second manufacturing method Will refer to Figures 14 to 16 A second method of manufacturing the CMOS image sensor 1 according to the first embodiment is described. Fig.14 The processes of steps S1 and S2 in the above method correspond to the processes of steps S1 and S2 in the first manufacturing method ( Fig.11 ), so its description is omitted.

[0077] After the process of step S2, Fig.14 As shown in the process of step S3 in FIG. 1 , the first anti-reflection film 54 and the transparent layer 55b of the super surface layer 55 are formed. The first anti-reflection film 54 and the transparent layer 55b can be formed by the above-mentioned physical or chemical film forming method.

[0078] Next, if Fig.15 As shown in the process of step S4 in FIG. 1 , a hard mask 102 is formed on the transparent layer 55 b .

[0079] Next, if Fig.15 As shown in the process of step S5 in FIG. 1 , a resist mask 103 having a predetermined planar layout pattern is formed.

[0080] Next, if Fig.15 As shown in the process of step S6 in FIG. 5 , the transparent layer 55 b is dry-etched.

[0081] Next, if Fig.16 As shown in the process of step S7 in FIG. 1 , a groove 58 and a pad opening 59 for forming the sidewall protection film 57 are formed. For example, anisotropic dry etching is used to form the groove 58 and the pad opening 59. After the dry etching, the resist mask 103 is removed.

[0082] Next, if Fig.16As shown in the process of step S8 in FIG. 5 , the fine structure 55a of the super surface layer 55 is formed. For example, the pattern formed in the process of step S7 is filled with titanium oxide or the like using the ALD method or the like. In addition, a titanium oxide film is also formed on the upper part of the transparent layer 55b.

[0083] Although not shown, the second anti-reflection film 56 may be formed after the process of step S8. The second anti-reflection film 56 may be formed to constitute the side wall protection film 57 together with the titanium oxide film.

[0084] The second manufacturing method is different from the first manufacturing method in that the second material constituting the fine structure 55 a constitutes the side wall protection film 57 .

[0085] <<4. Manufacturing method of the second embodiment>> - First manufacturing method Will refer to Fig.17 A first manufacturing method of the CMOS image sensor 1 according to the second embodiment is described. Since the processes of steps S1 to S8 of the first manufacturing method of the second embodiment are the same as those of steps S1 to S8 of the second manufacturing method of the first embodiment, description thereof will be omitted.

[0086] After the process of step S8, Fig.17 As shown in the process of step S9 in FIG. 5 , the first portion 61a of the light shielding film 61 is formed to fill the groove 58. The light shielding film 61 can be formed by the various film forming methods described above.

[0087] Next, if Fig.17 As shown in the process of step S10 in FIG. 1 , the second anti-reflection film 56 is formed on the upper part of the super surface layer 55 and the upper part of the first part 61a of the light shielding film 61. The second anti-reflection film 56 can be formed by the above-mentioned various film forming methods.

[0088] Although not shown, after the process of step S10 , the second portion 61 b ​​of the light shielding film 61 may be formed on the upper portion of the first portion 61 a via the second anti-reflection film 56 .

[0089] - Second manufacturing method Will refer to Fig.18 A second manufacturing method of the CMOS image sensor 1 according to the second embodiment is described. Since the processes of steps S1 to S8 of the second manufacturing method of the second embodiment are the same as those of steps S1 to S8 of the second manufacturing method of the first embodiment, the description thereof will be omitted.

[0090] like Fig.18As shown in the process of step S9 in the figure, a second anti-reflection film 56 is formed on the upper part of the super surface layer 55. The second anti-reflection film 56 can be formed by the above-mentioned various film forming methods. The second anti-reflection film 56 can be formed as a side wall protection film 57 to constitute the side wall of the spacer layer 53 and the super surface layer 55.

[0091] like Fig.18 As shown in the process of step S10, the first portion 61a of the light shielding film 61 is formed to fill the groove 58. The light shielding film 61 can be formed by the above-mentioned various film forming methods.

[0092] Although not shown, after the process of step S10 , the second portion 61 b ​​of the light shielding film 61 may be formed on the upper portion of the first portion 61 a .

[0093] <<5. Application examples in electronic equipment>> Note that the present technology is not limited to application to solid-state imaging devices. That is, the present technology can be applied to all electronic devices that use solid-state imaging devices in image capturing units (photoelectric conversion units), such as imaging devices such as digital cameras or video cameras, mobile terminal devices with imaging functions, or copiers that use solid-state imaging devices in image reading units. The solid-state imaging device can be formed as a single chip, or can be formed as a module with an imaging function in which an imaging unit and a signal processing unit or an optical system are packaged together.

[0094] Fig.19 This is a block diagram showing a configuration example of an imaging device as an electronic device to which the present technology is applied.

[0095] Fig.19 The imaging device 501 includes a lens group 511, using Figure 1 The CMOS image sensor 1 in the embodiment includes a solid-state imaging device (imaging device) 512 and a digital signal processor (DSP) circuit 513 as a camera signal processing circuit.

[0096] Furthermore, the imaging device 501 includes a frame memory 514, a display unit 515, a recording unit 516, an operation unit 517, and a power supply unit 518. The DSP circuit 513, the frame memory 514, the display unit 515, the recording unit 516, the operation unit 517, and the power supply unit 518 are connected to each other via a bus 519.

[0097] The lens group 511 captures incident light (image light) from a subject and forms an image on an imaging surface of the solid-state imaging device 512. The solid-state imaging device 512 converts the amount of incident light formed on the imaging surface by the lens group 511 into an electrical signal for each pixel and outputs the electrical signal as a pixel signal.

[0098] The display unit 515 includes, for example, a thin display such as a liquid crystal display (LCD) or an organic electroluminescent (EL) display, and displays a moving image or a still image captured by the solid-state imaging device 512. The recording unit 516 records the moving image or the still image captured by the solid-state imaging device 512 on a recording medium such as a hard disk or a semiconductor memory.

[0099] <<6. Example of using the light detection device>> Fig. 20 1 is a diagram showing a usage example of the above-mentioned CMOS image sensor 1 .

[0100] The above-described CMOS image sensor 1 can be used, for example, in various cases for sensing light such as visible light, infrared light, ultraviolet light, and X-rays as described below.

[0101] - Devices for capturing images for viewing, such as digital cameras or portable devices with camera functions; - Devices used for traffic purposes to achieve safe driving such as automatic parking, driver status recognition, etc., such as on-board sensors that image the front, rear, surroundings, interior, etc. of the vehicle, surveillance cameras that monitor moving vehicles and roads, and distance measurement sensors that measure the distance between vehicles; - Devices for home appliances such as televisions, refrigerators, and air conditioners that image a user's gestures and perform device operations based on the gestures; - Devices for medical and health care purposes, such as endoscopes and devices for angiography by receiving infrared light; - Devices used for security purposes, such as security surveillance cameras and personal identification cameras; - Devices for beauty treatments, such as skin measuring instruments for skin imaging and microscopes for scalp imaging; - Devices for sports, such as action cameras and wearable cameras for sports applications; - Devices used in agriculture, such as cameras for monitoring the condition of fields or crops;

[0102] <<7. Others>> <Example of Combination> The present technology can also be configured as follows.

[0103] (1) A light detection device, comprising: A semiconductor substrate including a photoelectric conversion unit; A spacer layer disposed on the semiconductor substrate; A supersurface layer disposed on the spacer layer; and A sidewall protection film is provided at least on the sidewall of the spacer layer. (2) The light detecting device according to (1), wherein the sidewall protection film also constitutes a sidewall of the super surface layer. (3) The light detecting device according to (2), wherein the side wall protection film is formed by extending a side wall portion of the super surface layer downward. (4) The light detecting device according to any one of (1) to (3), wherein a film thickness of the side wall protection film is 10 nm to 5000 nm. (5) The light detection device according to any one of (1) to (4), further including a light shielding film covering the side wall protection film. (6) The light detecting device according to (5), wherein the light shielding film includes a first portion provided to cover the side wall protection film and a second portion provided on an upper portion of the super surface layer. (7) The light detection device according to (5) or (6), wherein a material of the light shielding film is a metal or a black resist material. (8) The light detecting device according to any one of (1) to (7), wherein the supersurface layer includes a fine structure made of at least a first material and a transparent layer made of at least a second material. (9) The light detecting device according to (8), wherein a material of the side wall protection film is the same material as a material of the super surface layer. (10) The light detecting device according to any one of (1) to (9), wherein a material of the side wall protection film is an inorganic material. (11) The light detecting device according to any one of (1) to (10), wherein a material of the spacer layer is an inorganic material or an organic material. (12) The light detecting device according to any one of (1) to (11), wherein a material of the spacer layer is a material different from a material of the supersurface layer. (13) The light detecting device according to any one of (1) to (12), further comprising a first anti-reflection film between the supersurface layer and the spacer layer. (14) The light detecting device according to (13) further includes a second anti-reflection film on the upper portion of the super surface layer. (15) The light detecting device according to (14), wherein the side wall protection film includes a layer of the first anti-reflection film or a layer of the second anti-reflection film. (16) The photodetection device according to (14) or (15), wherein a material of the first anti-reflection film and a material of the second anti-reflection film include silicon nitride. (17) An electronic device comprising a light detection device, wherein the light detection device comprises: A substrate including a photoelectric conversion unit; A spacer layer disposed on the substrate; A supersurface layer disposed on the spacer layer; and A sidewall protection film is provided at least on the sidewall of the spacer layer. Reference numerals list

[0104] 51Semiconductor substrate 52 color filters 53 Interval layer 53a Side wall portion 54First anti-reflection film 55 Super Surface Layer 55a Fine structure 55b Transparent layer 56 Second anti-reflection film 57 side wall protection film 58 Grooves 59 pad opening 61 shading film 61aPart I 61bPart 2 101 shading film 102 Hard Mask 103 resist mask

Claims

1. A light detection device, comprising: A semiconductor substrate including a photoelectric conversion unit; A spacer layer disposed on the semiconductor substrate; A super surface layer disposed on the spacer layer; as well as A sidewall protection film is provided at least on the sidewall of the spacer layer. 2 . The light detecting device according to claim 1 , wherein the sidewall protection film constitutes a sidewall of the super surface layer. 3 . The light detecting device according to claim 2 , wherein the sidewall protection film is formed by extending a sidewall portion of the super surface layer downward. 4 . The light detecting device according to claim 1 , wherein a film thickness of the side wall protection film is 10 nm to 5000 nm. 5 . The light detecting device according to claim 1 , further comprising a light shielding film covering the side wall protection film. 6 . The light detecting device according to claim 5 , wherein the light shielding film includes a first portion provided to cover the sidewall protection film and a second portion provided on an upper portion of the super surface layer. 7 . The light detecting device according to claim 5 , wherein a material of the light shielding film is a metal or a black resist material. 8 . The light detecting device according to claim 1 , wherein the supersurface layer includes a fine structure made of at least a first material and a transparent layer made of at least a second material. 9 . The light detecting device according to claim 8 , wherein a material of the sidewall protection film is the same material as a material of the super surface layer. 10 . The light detecting device according to claim 9 , wherein a material of the side wall protection film is an inorganic material. The light detecting device according to claim 1 , wherein a material of the spacer layer is an inorganic material or an organic material. 12 . The light detecting device according to claim 1 , wherein a material of the spacer layer is a material different from a material of the supersurface layer. 13 . The light detecting device according to claim 1 , further comprising a first anti-reflection film between the metasurface layer and the spacer layer. 14 . The light detecting device according to claim 13 , further comprising a second anti-reflection film on an upper portion of the metasurface layer. 15 . The light detecting device according to claim 14 , wherein the side wall protection film includes a layer of the first anti-reflection film or a layer of the second anti-reflection film. 16 . The light detecting device according to claim 14 , wherein a material of the first anti-reflection film and a material of the second anti-reflection film include silicon nitride.

17. An electronic device, comprising a light detection device, the light detection device comprising: A substrate including a photoelectric conversion unit; A spacer layer disposed on the substrate; A super surface layer disposed on the spacer layer; as well as A sidewall protection film is provided at least on the sidewall of the spacer layer.

Images