Patent Publication Number: US-2023163149-A1

Title: Solid-state imaging device and electronic device

Description:
TECHNICAL FIELD 
     The present disclosure relates to a solid-state imaging device and an electronic device. 
     BACKGROUND ART 
     Conventionally, a solid-state imaging device having a pixel region in which a photoelectric conversion part, a transparent insulating layer, a color filter, and a microlens are laminated in this order has been proposed (see Patent Document 1, for example). In the solid-state imaging device described in Patent Document 1, a separation part containing a low refractive material is disposed between color filters, and a waveguide is formed with the color filter as the core and the separation part (waveguide wall part) as the cladding, so that diffusion of incident light in the color filter is prevented and sensitivity of each pixel is improved. 
     Furthermore, on the end side (high image height) of the pixel region, incident light is obliquely incident on the microlens. 
     CITATION LIST 
     Patent Document 
     
         
         Patent Document 1: International Patent Application Publication No. 2012/073402 
       
    
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     However, in the solid-state imaging device described in Patent Document 1, in a case where incident light is obliquely incident on the microlens, for example, there is a possibility that the incident light hits the microlens side of the waveguide wall part, a part of the incident light is reflected (scattered) by the waveguide wall part, and the scattered light enters the adjacent pixel to cause color mixture. 
     An object of the present disclosure is to provide a solid-state imaging device and an electronic device capable of enhancing pixel sensitivity and preventing color mixture. 
     Solutions to Problems 
     A solid-state imaging device of the present disclosure includes (a) a plurality of microlenses that condenses incident light, (b) a plurality of color filters that transmits light of a specific wavelength included in the condensed incident light, (c) a plurality of photoelectric conversion parts on which light having a specific wavelength transmitted through the color filter is incident, and (d) a plurality of waveguide wall parts arranged between the color filters and surrounding the color filter, and (e) each of the plurality of waveguide wall parts is formed in a position subjected to pupil correction. 
     An electronic device of the present disclosure includes (a) a solid-state imaging device that includes a plurality of microlenses that condenses incident light, a plurality of color filters that transmits light of a specific wavelength included in the condensed incident light, a plurality of photoelectric conversion parts on which light having a specific wavelength transmitted through the color filter is incident, and a plurality of waveguide wall parts arranged between the color filters and surrounding the color filter, each of the plurality of waveguide wall parts formed in a position subjected to pupil correction, (b) an optical lens that forms an image of image light from a subject on an imaging surface of the solid-state imaging device, and (c) a signal processing circuit that performs signal processing on a signal output from the solid-state imaging device. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a diagram illustrating an overall configuration of a solid-state imaging device according to a first embodiment. 
         FIG.  2    is a diagram illustrating a cross-sectional configuration of the solid-state imaging device cut along line A-A in  FIG.  1   . 
         FIG.  3    is a diagram illustrating a deviation direction of a waveguide wall part of each stage. 
         FIG.  4    is a diagram illustrating an amount of deviation of a waveguide wall part of each stage. 
         FIG.  5 A  is a diagram illustrating a flow of a manufacturing process of the solid-state imaging device. 
         FIG.  5 B  is a diagram illustrating a flow of the manufacturing process of the solid-state imaging device. 
         FIG.  5 C  is a diagram illustrating a flow of the manufacturing process of the solid-state imaging device. 
         FIG.  5 D  is a diagram illustrating a flow of the manufacturing process of the solid-state imaging device. 
         FIG.  5 E  is a diagram illustrating a flow of the manufacturing process of the solid-state imaging device. 
         FIG.  6    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  7    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  8    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  9    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  10    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  11    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  12    is a diagram illustrating a cross-sectional configuration of a solid-state imaging device according to a modification. 
         FIG.  13    is a schematic configuration diagram of an electronic device according to a second embodiment. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     Hereinafter, an example of a solid-state imaging device  1  and an electronic device according to embodiments of the present disclosure will be described with reference to  FIGS.  1  to  13   . Embodiments of the present disclosure will be described in the following order. Note that the present disclosure is not limited to the following examples. Furthermore, the effect described in the present specification is merely an illustration and is not restrictive. Hence, other effects can be obtained. 
     1. First Embodiment: Solid-State Imaging Device 
     
         
         
           
             1-1 Overall configuration of solid-state imaging device 
             1-2 Configuration of main part 
             1-3 Method of forming color filter layer 
             1-4 Modification 
           
         
       
    
     2. Second Embodiment: Example of Application to Electronic Device 
     1. First Embodiment: Solid-State Imaging Device 
     [1-1 Overall Configuration of Solid-State Imaging Device] 
     A solid-state imaging device  1  according to a first embodiment of the present disclosure will be described.  FIG.  1    is a schematic configuration diagram illustrating the whole solid-state imaging device  1  according to the first embodiment of the present disclosure. 
     The solid-state imaging device  1  in  FIG.  1    is a back-illuminated complementary metal oxide semiconductor (CMOS) image sensor. As illustrated in  FIG.  13   , the solid-state imaging device  1  ( 101 ) captures image light (incident light  106 ) from a subject via an optical lens  102 , converts a light amount of the incident light  106  forming an image on an imaging surface into an electrical signal in units of pixels, and outputs the electrical signal as a pixel signal. 
     As illustrated in  FIG.  1   , the solid-state imaging device  1  includes a substrate  2 , a pixel region  3 , a vertical drive circuit  4 , a column signal processing circuit  5 , a horizontal drive circuit  6 , an output circuit  7 , and a control circuit  8 . 
     The pixel region  3  has a plurality of pixels  9  regularly arranged in a two-dimensional array on the substrate  2 . The pixel  9  includes a photoelectric conversion part  23  illustrated in  FIG.  2    and a plurality of pixel transistors (not illustrated). As the plurality of pixel transistors, four transistors of a transfer transistor, a reset transistor, a selection transistor, and an amplifier transistor can be adopted, for example. Furthermore, for example, three transistors excluding the selection transistor may be adopted. 
     The vertical drive circuit  4  includes a shift register, for example, selects a desired pixel drive wiring  10 , supplies a pulse for driving the pixels  9  to the selected pixel drive wiring  10 , and drives the pixels  9  in row units. That is, the vertical drive circuit  4  selectively scans the pixels  9  of the pixel region  3  in the vertical direction sequentially in row units, and supplies the column signal processing circuit  5  with a pixel signal based on a signal charge generated according to the amount of received light in the photoelectric conversion part  23  of each pixel  9  through a vertical signal line  11 . 
     The column signal processing circuit  5  is arranged for each column of the pixels  9 , for example, and performs signal processing such as noise removal on signals output from the pixels  9  for one row for each pixel column. For example, the column signal processing circuit  5  performs signal processing such as correlated double sampling (CDS) for removing pixel-specific fixed pattern noise and analog digital (AD) conversion. 
     The horizontal drive circuit  6  includes a shift register, for example, sequentially selects the column signal processing circuits  5  by sequentially outputting horizontal scanning pulses to the column signal processing circuits  5 , and causes each of the column signal processing circuits  5  to output a pixel signal subjected to signal processing to a horizontal signal line  12 . 
     The output circuit  7  performs signal processing on pixel signals sequentially supplied from the column signal processing circuits  5  through the horizontal signal line  12 , and outputs the processed pixel signals. As the signal processing, for example, buffering, black level adjustment, column variation correction, various digital signal processing, and the like can be used. 
     On the basis of a vertical synchronization signal, a horizontal synchronization signal, and a master clock signal, the control circuit  8  generates a clock signal and a control signal, which serve as a reference for operations of the vertical drive circuit  4 , the column signal processing circuit  5 , the horizontal drive circuit  6 , and the like. Then, the control circuit  8  outputs the generated clock signal and control signal to the vertical drive circuit  4 , the column signal processing circuit  5 , the horizontal drive circuit  6 , and the like. 
     [1-2 Configuration of Main Part] 
     Next, a detailed structure of the solid-state imaging device  1  of  FIG.  1    will be described.  FIG.  2    is a diagram illustrating a cross-sectional configuration of the solid-state imaging device  1  in a case where the solid-state imaging device  1  is cut along line A-A in  FIG.  1   . 
     As illustrated in  FIG.  2   , the solid-state imaging device  1  includes a light receiving layer  16  formed by laminating the substrate  2 , an insulating film  13 , a light shielding film  14 , and a flattening film  15  in this order. Furthermore, a condensing layer  19  in which a color filter layer  17  and a microlens array  18  are laminated in this order is formed on a surface (hereinafter also referred to as “back surface S 1 ”) of the light receiving layer  16  on the flattening film  15  side. Moreover, a wiring layer  20  and a support substrate  21  are laminated in this order on a surface (hereinafter also referred to as “front surface S 2 ”) of the light receiving layer  16  on the substrate  2  side. Note that since the back surface S 1  of the light receiving layer  16  and the back surface of the flattening film  15  are the same surface, the back surface of the flattening film  15  is also referred to as a “back surface S 1 ” in the following description. Furthermore, since the front surface S 2  of the light receiving layer  16  and the front surface of the substrate  2  are the same surface, the surface of the substrate  2  is also referred to as “front surface S 2 ” in the following description. 
     The substrate  2  includes, for example, a semiconductor substrate including silicon (Si), and forms the pixel region  3 . In the pixel region  3 , a plurality of pixels  9  including the photoelectric conversion part  23  is arranged in a two-dimensional array. Each of the photoelectric conversion parts  23  is embedded in the substrate  2  to form a photodiode, generates a signal charge corresponding to the light amount of incident light  22 , and accumulates the generated signal charge. 
     Furthermore, each photoelectric conversion part  23  is physically separated by a pixel separation part  24 . The pixel separation part  24  is formed in a lattice shape so as to surround each photoelectric conversion part  23 . The pixel separation part  24  includes a bottomed trench part  25  (groove part) formed in the depth direction from a surface (hereinafter also referred to as “back surface S 3 ”) side of the substrate  2  facing the insulating film  13 . The trench part  25  is formed in a lattice shape such that its inner side surface and bottom surface form the outer shape of the pixel separation part  24 . Furthermore, the insulating film  13  covering the back surface S 3  side of the substrate  2  is embedded inside the trench part  25 . 
     The insulating film  13  continuously covers the entire back surface S 3  side (the entire light receiving surface side) of the substrate  2  and the inside of the trench part  25 . As the material of the insulating film  13 , an insulator can be used, for example. Specifically, silicon oxide (SiO 2 ) and silicon nitride (SiN) can be adopted. Furthermore, the light shielding film  14  is formed in a lattice shape that opens the light receiving surface side of each of the plurality of photoelectric conversion parts  23  in a part of the insulating film  13  on the back surface S 4  side so as not to allow light to leak into the adjacent pixels  9 . Furthermore, the flattening film  15  continuously covers the entire back surface S 5  side (entire light receiving surface side) of the insulating film  13  including the light shielding film  14  such that the back surface S 1  of the light receiving layer  16  is a flat surface with no unevenness. 
     The color filter layer  17  includes a waveguide module  26  for each pixel  9  on the back surface S 1  side (light receiving surface side) of the flattening film  15 . The waveguide module  26  is formed by laminating a plurality of waveguides  27 .  FIG.  2    illustrates a case where there are three waveguides  27 , and the height of all waveguide wall parts  29  and the height of all filter component members  28  are the same. Each of the waveguides  27  includes the filter component member  28  and the waveguide wall part  29  (separation part). 
     The filter component member  28  is an optical filter that transmits light of a specific wavelength included in the incident light  22  condensed by a microlens  30 . As the light having a specific wavelength, red light, green light, and blue light can be adopted, for example. Furthermore, as each of the filter component members  28  included in the same waveguide module  26 , a filter component member  28  that transmits light of the same color is used. As a result, a color filter  33  including the plurality of filter component members  28  included in the waveguide module  26  is formed. The light having the specific wavelength transmitted through the color filter  33  is incident on the photoelectric conversion part  23 . Furthermore, for example, a Bayer array can be adopted as an array pattern of the filter component member  28  in a case of being viewed from the microlens  30  side. As the material of the filter component member  28 , an organic glass material having a refractive index of 1.4 to 1.9 can be adopted, for example. 
     The waveguide wall part  29  is formed so as to surround the filter component members  28  included in the same waveguide  27 . Furthermore, the waveguide wall part  29  is shared by the waveguides  27  of the same stage and adjacent to each other. That is, the waveguide wall part  29  of each stage is formed in a lattice shape so as to surround the filter component members  28  of the same stage. In other words, a plurality of waveguide wall parts  29  is arranged between the color filters  33  of all the filter component members  28 . As the material of the waveguide wall part  29 , a low refractive material having a refractive index lower than that of the filter component member  28  included in the same waveguide  27  can be adopted, for example. As the low refractive material, a low refractive index resin having a refractive index of 1.0 to 1.2 can be adopted, for example. As a result, in the waveguide  27 , the core is formed by the filter component member  28  having the relatively high refractive index, and the cladding is formed by the waveguide wall part  29  having the relatively low refractive index. Furthermore,  FIG.  2    illustrates a case where the height, the width, and the material of the waveguide wall parts  29  of the stages are the same. That is, the waveguide wall parts  29  of the stages are members having the same shape and the same material. Note that the “width of the waveguide wall part  29 ” is a width of the waveguide wall part  29  in a direction parallel to the back surface S 3  (light receiving surface) of the substrate  2  in a cross section perpendicular to the back surface S 3  (light receiving surface) of the substrate  2 . One example of the “width of the waveguide wall part  29 ” is, in a case where the waveguide wall part  29  is viewed from the microlens  30  side, the length of the waveguide wall part  29  in a direction intersecting (orthogonal to, or the like) a direction in which the waveguide wall part  29  extends. 
     Furthermore, each of the plurality of waveguide wall parts  29  is formed in a position where pupil correction is individually performed. That is, pupil correction is performed on each of the plurality of waveguides  27  included in each waveguide module  26  on the end side (high image height) of the pixel region  3 . Specifically, as illustrated in  FIGS.  2  and  3   , among the waveguide wall parts  29  stacked on top of one another, the waveguide wall part  29  of a stage on the microlens array  18  side (microlens  30  side) is shifted toward the central part of the pixel region  3  than the waveguide wall part  29  of a stage on the photoelectric conversion part  23  side. In  FIG.  2   , the central axis of the lower waveguide wall part  29  coincides with the central axis of the pixel separation part  24 , the central axis of the middle waveguide  27  is shifted toward the central part of the pixel region  3  from the central axis of the lower waveguide wall part  29 , and the central axis of the upper waveguide wall part  29  is shifted toward the central part of the pixel region  3  from the central axis of the middle waveguide  27 . Furthermore, in  FIG.  3   , when viewed from the microlens array  18  side, in the waveguide module  26  in the region on the left side of the central part of the pixel region  3  in  FIG.  3   , the middle and upper waveguide wall parts  29  are shifted to the right side in  FIG.  3   , in the waveguide module  26  in the region on the lower side of the central part of the pixel region  3  in  FIG.  3   , the middle and upper waveguide wall parts  29  are shifted to the upper side in  FIG.  3   , and in the waveguide module  26  in the region on the lower left side of the central part of the pixel region  3  in  FIG.  3   , the middle and upper waveguide wall parts  29  are shifted to the upper right side in  FIG.  3   . Note that in  FIG.  3   , the filter component member  28  is omitted to facilitate understanding of the state of deviation of the waveguide wall part  29 . Furthermore,  FIG.  3    illustrates a case where the amounts of deviation of the waveguide wall parts  29  are the same. 
     Furthermore, as illustrated in  FIG.  4   , the amount of deviation between the uppermost waveguide wall part  29  and the lowermost waveguide wall part  29  is increased as the distance from the central part of the pixel region  3  is longer when viewed from the microlens array  18  side. In  FIG.  4   , the amount of deviation (=0) between the waveguide wall parts  29  in the waveguide module  26  at the central part of the pixel region  3  &lt; the amount of deviation between the waveguide wall parts  29  in the waveguide module  26  in a region slightly away from the central part of the pixel region  3 &lt; the amount of deviation between the waveguide wall parts  29  in the waveguide module  26  in a region significantly away from the pixel region  3 . Furthermore, in the waveguide wall parts  29  stacked on top of one another, the amount of deviation of the waveguide wall part  29  of the stage on the microlens array  18  side is within a range of ±x/2 of a width x of the waveguide wall part  29  of the stage on the photoelectric conversion part  23  side. That is, the amount of deviation is determined such that there is no gap between the waveguide wall parts  29  stacked on top of one another. 
     Furthermore, an optimum shift amount z of the waveguide wall part  29  can be calculated from, for example, Snell&#39;s law. Specifically, as illustrated in  FIG.  2   , the optimum shift amount z of the waveguide wall part  29  can be calculated according to the following Formula (1) on the basis of an incident angle A [deg] of the incident light  22 , a refractive index n of the filter component member  28  (color filter  33 ), and a height y of the waveguide wall part  29  to be shifted. 
         z=y ×tanB  (1)
 
       SinB= n /sinA 
     Here, B [deg] is a refraction angle of the filter component member  28  (color filter  33 ). 
     Here, the incident light  22  is obliquely incident on the microlens on the end side (high image height) of the pixel region  3 . In view of the above, in the waveguide module  26 , since the waveguide wall part  29  is formed in a position subjected to pupil correction, the obliquely incident incident light  22  can be prevented from hitting the microlens array  18  side (part indicated by circle  34  in  FIG.  2   ) of the waveguide wall part  29 , and the incident light  22  can be prevented from being scattered by the waveguide wall part  29 . Furthermore, in the microlens  30 , the incident light  22  is partially diffracted by the diffraction action of the microlens  30 , and the diffracted incident light  22  spreads. As a countermeasure, in the waveguide module  26 , since the zigzag waveguide is formed so as to extend in a direction parallel to the obliquely incident incident light  22 , light can be reflected at the interface between the filter component member  28  and the waveguide wall part  29 , the spread incident light  22  is returned to the central side of the pixel  9 , and entry of the incident light  22  into another pixel  9  can be curbed. 
     The microlens array  18  includes the microlens  30  for each pixel  9  on the back surface S 5  side (light receiving surface side) of the color filter layer  17 . Each of the microlenses  30  condenses image light (incident light  22 ) from a subject into the photoelectric conversion part  23  via the waveguide module  26 . 
     Furthermore, pupil correction is performed on each of the microlenses  30  on the end side (high image height) of the pixel region  3 . Specifically, as illustrated in  FIG.  2   , each of the microlenses  30  is shifted toward the central part of the pixel region  3  from the waveguide module  26 . Furthermore, the microlens  30  is formed to have a reduced height. A height H of the microlens  30  is, for example, preferably 300 nm or less, and more preferably 200 nm or less. As the height H, a distance between the top and the bottom of the microlens  30  can be adopted, for example. By reducing the height of the microlens  30 , even if the incident light  22  is partially diffracted by the diffraction action of the microlens  30 , the entire diffracted incident light  22  can be guided into the waveguide module  26  before the diffracted incident light  22  spreads, and the incident light  22  can be prevented from entering the adjacent pixel  9 . 
     The wiring layer  20  is formed on the front surface S 2  side of the substrate  2 , and includes an interlayer insulating film  31  and wiring  32  laminated in a plurality of layers with the interlayer insulating film  31  interposed therebetween. Then, the wiring layer  20  drives the pixel transistors included in each pixel  9  via the plurality of layers of wiring  32 . 
     The support substrate  21  is formed on a surface of the wiring layer  20  on a side opposite to a side facing the substrate  2 . The support substrate  21  is a substrate for securing the strength of the substrate  2  at the manufacturing stage of the solid-state imaging device  1 . As the material of the support substrate  21 , silicon (Si) can be used, for example. 
     In the solid-state imaging device  1  having the above configuration, light is emitted from the back surface side (back surface S 1  side of light receiving layer  16 ) of the substrate  2 , the emitted light passes through the microlens  30  and the waveguide module  26 , and the transmitted light is photoelectrically converted by the photoelectric conversion part  23  to generate a signal charge. Then, the generated signal charge is output as a pixel signal by the vertical signal line  11  illustrated in  FIG.  1    including the wiring  32 , via the pixel transistors formed on the front surface S 2  side of the substrate  2 . 
     [1-3 Method of Forming Color Filter Layer] 
     Next, a method of forming the color filter layer  17  in the solid-state imaging device  1  will be described. 
     First, as illustrated in  FIG.  5 A , the waveguide wall part  29  of the lower waveguide  27  among the lower, middle, and upper waveguides  27  illustrated in  FIG.  3    is formed on the back surface S 1  of the light receiving layer  16 . Subsequently, as illustrated in  FIG.  5 B , the filter component member  28  is formed in each space surrounded by the formed waveguide wall part  29  to form the lower waveguide  27 . Subsequently, as illustrated in  FIG.  5 C , the waveguide wall part  29  of the middle waveguide  27  is formed on the waveguide wall part  29  of the lower waveguide  27  so as to be shifted toward the central part of the pixel region  3  from the waveguide wall part  29  of the lower waveguide  27 . Subsequently, as illustrated in  FIG.  5 D , the filter component member  28  is formed in each space surrounded by the formed waveguide wall part  29  to form the middle waveguide  27 . Subsequently, as illustrated in  FIG.  5 E , the waveguide wall part  29  of the upper waveguide  27  is formed on the waveguide wall part  29  of the middle waveguide  27  so as to be shifted toward the central part of the pixel region  3  from the waveguide wall part  29  of the middle waveguide  27 , and the filter component member  28  is formed in each space surrounded by the formed waveguide wall part  29  to form the upper waveguide  27 . As a result, the color filter layer  17  including the plurality of waveguide modules  26  is obtained. 
     As described above, the solid-state imaging device  1  of the first embodiment includes the plurality of waveguide wall parts  29  surrounding the color filters  33  between the color filters  33 . Then, each of the plurality of waveguide wall parts  29  is formed in a position subjected to pupil correction. 
     Therefore, it is possible to form a waveguide in which the color filter  33  is used as the core and the plurality of waveguide wall parts  29  is used as the cladding, to curb diffusion of the incident light  22  to other pixels  9  in the color filter  33 , and to improve sensitivity of each pixel  9 . Furthermore, while the incident light  22  is normally obliquely incident on the microlens on the end side of the pixel region  3 , the obliquely incident incident light  22  can be prevented from hitting the microlens  30  side (part indicated by circle  34  in  FIG.  2   ) of the waveguide wall part  29 , the incident light  22  can be prevented from being reflected by the waveguide wall part  29 , and sensitivity of each pixel  9  can be further improved. Furthermore, it is possible to prevent scattered light from entering other pixels  9  to cause color mixture. Therefore, it is possible to provide the solid-state imaging device  1  capable of enhancing sensitivity of the pixel  9  and preventing color mixture. 
     Furthermore, the solid-state imaging device  1  of the first embodiment has a back-illuminated structure, that is, with the back surface S 1  of the substrate  2  opposite to the front surface S 2  of the substrate  2  on which the wiring layer  20  is formed as a light receiving surface, a structure in which the incident light  22  is incident from the back surface S 1  side of the substrate  2 . Therefore, the incident light  22  is incident on the photoelectric conversion part  23  without being restricted by the wiring layer  20 . Therefore, the opening of the photoelectric conversion part  23  can be made wide, and, for example, higher sensitivity can be achieved than that of a front-illuminated structure. 
     [1-4 Modification] 
     (1) Note that while the first embodiment describes an example in which there are three waveguide wall parts  29 , other configurations can be adopted. For example, as illustrated in  FIGS.  6  and  7   , the number of stages may be less than three or more than three.  FIG.  6    illustrates a case where there are two waveguide wall parts  29 . Furthermore,  FIG.  7    illustrates a case where there are four waveguide wall parts  29 . By increasing the number of the waveguide wall parts  29  to more than three, the waveguide formed by the entire waveguide module  26  can be tilted more steeply, which is suitable for a mobile device in which a high CRA (chie ray angle) is required. 
     (2) Furthermore, while the first embodiment describes an example in which the amount of deviation between the uppermost waveguide wall part  29  and the lowermost waveguide wall part  29  is increased as the distance from the central part of the pixel region  3  is longer, other configurations can be adopted. For example, a configuration may be adopted in which, when viewed from the microlens array  18  side, pupil correction is not performed on the waveguide wall part  29  in a region where the distance from the central part of the pixel region  3  is equal to or less than a predetermined distance, and pupil correction is performed only on the waveguide wall part  29  in a region where the distance from the central part of the pixel region  3  is larger than the predetermined distance. In this case, as the pupil correction, the amount of deviation between the uppermost waveguide wall part  29  and the lowermost waveguide wall part  29  may be constant regardless of the distance from the central part of the pixel region  3 . 
     (3) Furthermore, while the first embodiment describes an example in which the height of each waveguide wall part  29  is the same, other configurations can be adopted. For example, the height of the waveguide wall part  29  may be different between two or more waveguide wall parts  29  among the plurality of waveguide wall parts  29 . Specifically, as illustrated in  FIG.  8   , all of the waveguide wall parts  29  may have a different height, and the height of the waveguide wall part  29  on the microlens  30  side may be made lower than the height of the waveguide wall part  29  on the photoelectric conversion part  23  side. 
     Here, for example, when the waveguide module  26  is formed, in a case where the waveguide wall part  29  and the filter component member  28  have the same height in the first waveguide  27 , the second waveguide wall part  29  is supported by both the first waveguide wall part  29  and the first filter component member  28 . However, for example, in a case where the waveguide wall part  29  is higher than the filter component member  28  in the first waveguide  27 , the second waveguide wall part  29  is not supported by the first filter component member  28  and is supported only by the first waveguide  27 , and thus may collapse. As a countermeasure, when the height of the waveguide wall part  29  on the microlens  30  side is made lower than the height of the waveguide wall part  29  on the photoelectric conversion part  23  side, the waveguide wall part  29  is less likely to collapse, so that the waveguide wall part  29  can be formed relatively easily. Furthermore, for example, as compared with a configuration in which all the waveguide wall parts  29  are formed low, the number of the waveguide wall parts  29  can be reduced, and the manufacturing cost can be reduced. 
     (4) Furthermore, while the first embodiment describes an example in which the materials of the plurality of filter component members  28  are the same, other configurations can be adopted. For example, the material of the filter component member  28  may be different between two or more filter component members  28  among the plurality of filter component members  28 . Specifically, as illustrated in  FIG.  9   , the viscosity of the materials of the filter component members  28  other than the filter component member  28  closest to the microlens  30  may be made lower than the viscosity of the material of the filter component member  28  closest to the microlens  30 . In  FIG.  9   , the viscosity of the materials of the first and second filter component members  28  is made lower than the viscosity of the material of the third filter component member  28 . As the material of the filter component member  28 , a resist resin for a color filter can be adopted, for example. 
     Here, for example, when the waveguide module  26  is formed, in a case where there is unevenness on the surface of the filter component member  28  in the first waveguide  27 , the second waveguide wall part  29  may collapse because a part of the second waveguide wall part  29  is provided on the unevenness of the first filter component member  28 . Therefore, in a case where there is unevenness, the surface of the filter component member  28  needs to be polished and flattened after formation of the filter component member  28 . As a countermeasure, by making the viscosity of the material of the color filter  33  in stages other than the stage closest to the microlens  30  lower than the viscosity of the material of the color filter  33  in the stage closest to the microlens  30 , it is possible to reduce the unevenness of the surfaces of the first and second filter component members  28 , and eliminate the polishing process of the surface of the filter component member  28 . 
     (5) Furthermore, while the first embodiment describes an example in which the width of each waveguide wall part  29  is the same, other configurations can be adopted. For example, the width of the waveguide wall part  29  may be different between two or more waveguide wall parts  29  among the plurality of waveguide wall parts  29 . Specifically, as illustrated in  FIG.  10   , all of the waveguide wall parts  29  may have a different width, and the width of the waveguide wall part  29  on the photoelectric conversion part  23  side may be made larger than the width of the waveguide wall part  29  on the microlens  30  side. 
     Here, for example, when the waveguide module  26  is formed, in a case where the waveguide wall part  29  and the filter component member  28  have the same height in the first waveguide  27 , the second waveguide wall part  29  is supported by both the first waveguide wall part  29  and the first filter component member  28 . However, for example, in a case where the waveguide wall part  29  is higher than the filter component member  28  in the first waveguide  27 , the second waveguide wall part  29  is not supported by the first filter component member  28  and is supported only by the first waveguide  27 , and thus may collapse. As a countermeasure, by making the width of the waveguide wall part  29  on the photoelectric conversion part  23  side wider than the width of the waveguide wall part  29  on the microlens  30  side, the contact area between the waveguide wall parts  29  can be increased, and the waveguide wall part  29  is less likely to collapse, so that the waveguide wall part  29  can be formed relatively easily. 
     (6) Furthermore, while the first embodiment describes an example in which the amount of deviation of each waveguide wall part  29  is the same, other configurations can be adopted. For example, the amount of deviation of the waveguide wall part  29  may be different between two or more waveguide wall parts  29  among the plurality of waveguide wall parts  29 . Specifically, as illustrated in  FIG.  11   , all of the waveguide wall parts  29  may have different amounts of deviation, and the amounts of deviation of the waveguide wall parts  29  on the microlens  30  side may be made larger than the amounts of deviation of the waveguide wall parts  29  on the photoelectric conversion part  23  side. In  FIG.  11   , the magnitude relationship of the amount of deviation is as follows: the amount of deviation between the third waveguide wall part  29  and the fourth waveguide wall part  29 &gt; the amount of deviation between the second waveguide wall part  29  and the third waveguide wall part  29 &gt; the amount of deviation between the first waveguide wall part  29  and the second waveguide wall part  29 . 
     Here, since the incident light  22  condensed by the microlens  30  is refracted at the interface between the microlens  30  and the filter component member  28 , the refraction angle becomes smaller than the incidence angle. As illustrated in  FIG.  11   , as the ratio (n 2 /n 1 ) between a refractive index n 1  of the microlens  30  and a refractive index n 2  of the filter component member  28  increases, the refractive angle of the incident light  22  is drastically reduced. In view of the above, by making the amount of deviation of the waveguide wall part  29  on the microlens  30  side larger than the amount of deviation of the waveguide wall part  29  on the photoelectric conversion part  23  side, it is possible to prevent the obliquely incident incident light  22  from hitting the microlens  30  side (part indicated by circle  34  in  FIG.  11   ) of the waveguide wall part  29  and to cause the light condensed by the microlens  30  to travel to the photoelectric conversion part  23  without hitting the waveguide wall parts  29 . As a result, sensitivity of each pixel  9  can be further improved. 
     Furthermore, in a case of adopting such a configuration, by combining the configuration in which the height of the waveguide wall part  29  on the microlens  30  side is lower than the height of the waveguide wall part  29  on the photoelectric conversion part  23  side in the plurality of waveguide wall parts  29  as illustrated in  FIG.  8   , the amount of deviation of the waveguide wall part  29  on the microlens  30  side is increased easily, and the waveguide wall part  29  can be formed relatively easily. 
     (7) Furthermore, while the first embodiment describes an example in which the overall height of the plurality of waveguide wall parts  29  is the same as the height of the color filter  33 , other configurations can be adopted. For example, the entire height of the plurality of waveguide wall parts  29  may be different from the height of the color filter  33 . Specifically, as illustrated in  FIG.  12   , the overall height of the plurality of waveguide wall parts  29  may be made higher than the height of the color filter  33 . In  FIG.  12   , the upper end side of the fifth waveguide wall part  29  protrudes from the color filter  33  and is located between the microlenses  30 . 
     Here, for example, in a case where the overall height of the plurality of waveguide wall parts  29  is made lower than the height of the color filter  33 , the uppermost waveguide wall part  29  is less likely to collapse, so that the waveguide wall part  29  can be relatively easily formed and the process difficulty level can be lowered. However, since the distance between the microlens  30  and the waveguide wall part  29  becomes long, the entire incident light  22  diffracted and spread by the microlens  30  cannot be guided into the waveguide module  26 , and the waveguide effect may be weakened. Furthermore, since a part of the incident light  22  passes through the color filter  33  of the adjacent pixel  9 , the incident light  22  may be weakened, and sensitivity of each pixel  9  may be lowered. On the other hand, by making the overall height of the plurality of waveguide wall parts  29  higher than the height of the color filter  33 , the entire diffracted incident light  22  can be guided into the waveguide module  26  before the diffracted incident light  22  spreads, and the waveguide effect can be enhanced. Furthermore, since the incident light  22  does not pass through the color filter  33  of the adjacent pixel  9 , sensitivity of each pixel  9  can be improved. 
     &lt;2. Second Embodiment: Example of Application to Electronic Device&gt; 
     The technology according to the present disclosure (present technology) may be applied to various electronic devices such as an imaging device like a digital still camera or a digital video camera, a mobile phone having an imaging function, or another device having an imaging function. 
       FIG.  13    is a diagram illustrating one example of a schematic configuration of an electronic device (e.g., camera) to which the technology according to the present disclosure (present technology) can be applied. 
     As illustrated in  FIG.  13   , an electronic device  100  includes a solid-state imaging device  101 , the optical lens  102 , a shutter device  103 , a drive circuit  104 , and a signal processing circuit  105 . 
     The optical lens  102  forms an image of image light (incident light  106 ) from a subject on an imaging surface of the solid-state imaging device  101 . As a result, signal charges are accumulated in the solid-state imaging device  101  over a certain period. The shutter device  103  controls a light irradiation period and a light shielding period for the solid-state imaging device  101 . The drive circuit  104  supplies a drive signal for controlling a transfer operation of the solid-state imaging device  101  and a shutter operation of the shutter device  103 . A signal of the solid-state imaging device  101  is transferred by a drive signal (timing signal) supplied from the drive circuit  104 . The signal processing circuit  105  performs various types of signal processing on a signal (pixel signal) output from the solid-state imaging device  101 . A video signal subjected to the signal processing is stored in a storage medium such as a memory or output to a monitor. 
     Note that the electronic device  100  to which the solid-state imaging device  1  can be applied is not limited to a camera, and the solid-state imaging device  1  can also be applied to other electronic devices. For example, the solid-state imaging device  1  may be applied to an imaging device such as a camera module for a mobile device like a mobile phone or a tablet terminal. 
     Hereinabove, one example of the electronic device to which the technology according to the present disclosure can be applied has been described. Among the configurations described above, the technology according to the present disclosure is applicable to the solid-state imaging device  101 . Specifically, the solid-state imaging device  1  in  FIG.  1    can be applied to the solid-state imaging device  101 . By applying the technology according to the present disclosure to the solid-state imaging device  101 , it is possible to capture an image with improved quality. 
     Note that the present technology can also be configured in the following manner. 
     (1) 
     A solid-state imaging device including: 
     a plurality of microlenses that condenses incident light; 
     a plurality of color filters that transmits light of a specific wavelength included in the condensed incident light; 
     a plurality of photoelectric conversion parts on which light having a specific wavelength transmitted through the color filter is incident; and 
     a plurality of waveguide wall parts arranged between the color filters and surrounding the color filter, 
     in which each of the plurality of waveguide wall parts is formed in a position subjected to pupil correction. 
     (2) 
     The solid-state imaging device according to (1) above, 
     in which the waveguide wall part includes a low refractive material having a refractive index lower than a refractive index of the color filter. 
     (3) 
     The solid-state imaging device according to (1) or (2) above, 
     in which a height of the waveguide wall part is different between two or more of the waveguide wall parts among the plurality of waveguide wall parts. 
     (4) 
     The solid-state imaging device according to (3) above, 
     in which a height of the waveguide wall part on the microlens side is lower than a height of the waveguide wall part on the photoelectric conversion part side. 
     (5) 
     The solid-state imaging device according to any one of (1) to (4) above, 
     in which the color filter includes a plurality of filter component members, and 
     a material of the filter component member is different between two or more of the filter component members among the plurality of filter component members. 
     (6) 
     The solid-state imaging device according to (5) above, 
     in which viscosity of a material of the color filter other than the color filter closest to the microlens is lower than viscosity of a material of the color filter closest to the microlens. 
     (7) 
     The solid-state imaging device according to any one of (1) to (6) above, 
     in which a width of the waveguide wall part is different between two or more of the waveguide wall parts among the plurality of waveguide wall parts. 
     In other words, (7) can also be described as “the solid-state imaging device according to any one of (1) to (6) above, in which 
     a width of the waveguide wall part in a direction parallel to the back surface S 3  (light receiving surface) of the substrate  2  in a cross section perpendicular to the back surface S 3  (light receiving surface) of the substrate  2  is different between two or more of the waveguide wall parts among the plurality of waveguide wall parts.” 
     The solid-state imaging device according to (7) above, 
     in which a width of the waveguide wall part on the photoelectric conversion part side is wider than a width of the waveguide wall part on the microlens side. 
     (9) 
     The solid-state imaging device according to any one of (1) to (8) above, 
     in which an amount of deviation of the waveguide wall part is different between two or more of the waveguide wall parts among the plurality of waveguide wall parts. 
     (10) 
     The solid-state imaging device according to (9) above, 
     in which an amount of deviation of the waveguide wall part on the microlens side is larger than an amount of deviation of the waveguide wall part on the photoelectric conversion part side. 
     (11) 
     The solid-state imaging device according to any one of (1) to (10) above, 
     in which an overall height of the plurality of waveguide wall parts is different from a height of the color filter. 
     (12) 
     The solid-state imaging device according to (11) above, 
     in which an overall height of the plurality of waveguide wall parts is higher than a height of the color filter. 
     (13) 
     The solid-state imaging device according to any one of (1) to (12) above, 
     in which the photoelectric conversion part has a back-illuminated structure. 
     (14) 
     The solid-state imaging device according to any one of (1) to (13) above, 
     in which a height of the microlens is 300 nm or less. 
     (15) 
     An electronic device including: 
     a solid-state imaging device that includes a plurality of microlenses that condenses incident light, a plurality of color filters that transmits light of a specific wavelength included in the condensed incident light, a plurality of photoelectric conversion parts on which light having a specific wavelength transmitted through the color filter is incident, and a plurality of waveguide wall parts arranged between the color filters and surrounding the color filter, each of the plurality of waveguide wall parts formed in a position subjected to pupil correction; 
     an optical lens that forms an image of image light from a subject on an imaging surface of the solid-state imaging device; and 
     a signal processing circuit that performs signal processing on a signal output from the solid-state imaging device. 
     REFERENCE SIGNS LIST 
     
         
           1  Solid-state imaging device 
           2  Substrate 
           3  Pixel region 
           4  Vertical drive circuit 
           5  Column signal processing circuit 
           6  Horizontal drive circuit 
           7  Output circuit 
           8  Control circuit 
           9  Pixel 
           10  Pixel drive wiring 
           11  Vertical signal line 
           12  Horizontal signal line 
           13  Insulating film 
           14  Light shielding film 
           15  Flattening film 
           16  Light receiving layer 
           17  Color filter layer 
           18  Microlens array 
           19  Condensing layer 
           20  Wiring layer 
           21  Support substrate 
           22  Incident light 
           23  Photoelectric conversion part 
           24  Pixel separation part 
           25  Trench part 
           26  Waveguide module 
           27  Waveguide 
           28  Filter component member 
           29  Waveguide wall part 
           30  Microlens 
           31  Interlayer insulating film 
           32  Wiring 
           33  Color filter 
           34  Circle 
           100  Electronic device 
           101  Solid-state imaging device 
           102  Optical lens 
           103  Shutter device 
           104  Drive circuit 
           105  Signal processing circuit 
           106  Incident light