Patent Publication Number: US-2021183928-A1

Title: Imaging element, method of manufacturing the same, and electronic appliance

Description:
TECHNICAL FIELD 
     The present technology relates to an imaging element, a method of manufacturing the same, and an electronic appliance, and more particularly, to an imaging element, a method of manufacturing the same, and an electronic appliance capable of reducing false signal output caused by reflected light of incident light. 
     BACKGROUND ART 
     A structure of a back-irradiation solid-state imaging apparatus is proposed. In the structure, a light-shielding wall is formed at a layer lower than a color filter layer to prevent incident light from going into an adjacent pixel (e.g., see Patent Document 1). Furthermore, the light-shielding wall is sometimes formed up to the height of the color filter layer (e.g., see Patent Document 2). 
     CITATION LIST 
     Patent Document 
     
         
         Patent Document 1: Japanese Patent Application Laid-Open No. 2013-251292 
         Patent Document 2: International Publication No. 2016/114154 
       
    
     SUMMARY OF THE INVENTION 
     Problems to be Solved by the Invention 
     Unfortunately, incident light is sometimes reflected on the surface of a semiconductor substrate or the surface of an on-chip lens (OCL), is re-reflected on a cover glass or an IR cut filter disposed on the upper side, and is then incident to a solid-state imaging apparatus again. Further ingenuity is needed for reducing false signal output called a flare and ghost. 
     The present technology has been made in view of such a situation, and can reduce the false signal output caused by reflected light of incident light. 
     Solutions to Problems 
     An imaging element of a first aspect of the present technology includes: a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting incident light; a color filter layer that is formed on the semiconductor substrate and that passes the incident light of a predetermined wavelength; a light-shielding wall that is formed at a pixel boundary on the semiconductor substrate so as to have a height greater than a height of the color filter layer; and a protective substrate that is disposed via a seal resin and that protects an upper-surface side of the color filter layer. 
     A method of manufacturing an imaging element of a second aspect of the present technology includes: forming a color filter layer that passes incident light of a predetermined wavelength on a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting the incident light; forming a light-shielding wall having a height greater than a height of the color filter layer at a pixel boundary on the semiconductor substrate; and bonding a protective substrate on an upper side of the color filter layer via a seal resin. 
     An electronic appliance of a third aspect of the present technology includes an imaging element including: a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting incident light; a color filter layer that is formed on the semiconductor substrate and that passes the incident light of a predetermined wavelength; a light-shielding wall that is formed at a pixel boundary on the semiconductor substrate so as to have a height greater than a height of the color filter layer; and a protective substrate that is disposed via a seal resin and that protects an upper-surface side of the color filter layer. 
     In the first to third aspects of the present technology, a color filter layer that passes incident light of a predetermined wavelength is formed on a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting the incident light, a light-shielding wall having a height greater than a height of the color filter layer is formed at a pixel boundary on the semiconductor substrate, and a protective substrate is bonded on an upper side of the color filter layer via a seal resin. 
     The imaging element and the electronic appliance may be independent apparatus, or may be a module incorporated in another apparatus. 
     Effects of the Invention 
     According to the first to third aspects of the present technology, false signal output caused by reflected light of incident light can be reduced. 
     Note that the effects described here are not necessarily limitative, and any of the effects described in the present disclosure may be exhibited. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a cross-sectional view of an imaging element as an embodiment to which the present technology is applied. 
         FIG. 2  is a cross-sectional view illustrating a first configuration example of the imaging element in  FIG. 1 . 
         FIG. 3  illustrates an effect in a case where the present technology is applied. 
         FIG. 4  illustrates a manufacturing method in the first configuration example. 
         FIG. 5  illustrates the manufacturing method in the first configuration example. 
         FIG. 6  illustrates disposition in a case where exit pupil correction is performed. 
         FIG. 7  is a cross-sectional view illustrating a first variation of the first configuration example. 
         FIG. 8  is a cross-sectional view illustrating a second variation of the first configuration example. 
         FIG. 9  is a cross-sectional view illustrating a second configuration example of the imaging element in  FIG. 1 . 
         FIG. 10  illustrates an effect of wavy structure. 
         FIG. 11  illustrates an effect of the wavy structure. 
         FIG. 12  illustrates a method of forming the wavy structure of a light-shielding wall. 
         FIG. 13  illustrates a manufacturing method in the second configuration example. 
         FIG. 14  illustrates the manufacturing method in the second configuration example. 
         FIG. 15  is a plan view illustrating a first variation of the second configuration example. 
         FIG. 16  illustrates an effect of the first variation of the second configuration example. 
         FIG. 17  illustrates a forming method in the first variation of the second configuration example. 
         FIG. 18  is a plan view illustrating a second variation of the second configuration example. 
         FIG. 19  illustrates a forming method in the second variation of the second configuration example. 
         FIG. 20  is a plan view illustrating the first variation of the second configuration example and another example of the second variation. 
         FIG. 21  is a cross-sectional view illustrating a third configuration example of the imaging element in  FIG. 1 . 
         FIG. 22  illustrates a manufacturing method in the third configuration example. 
         FIG. 23  illustrates the manufacturing method in the third configuration example. 
         FIG. 24  is a cross-sectional view illustrating a first variation of the third configuration example. 
         FIG. 25  is a cross-sectional view illustrating a second variation of the third configuration example. 
         FIG. 26  is a cross-sectional view illustrating a fourth configuration example of the imaging element in  FIG. 1 . 
         FIG. 27  illustrates a manufacturing method in the fourth configuration example. 
         FIG. 28  illustrates the manufacturing method in the fourth configuration example. 
         FIG. 29  illustrates the manufacturing method in the fourth configuration example. 
         FIG. 30  is a cross-sectional view illustrating a fifth configuration example of the imaging element in  FIG. 1 . 
         FIG. 31  is a cross-sectional view illustrating a first variation of the fifth configuration example. 
         FIG. 32  is a cross-sectional view illustrating a second variation of the fifth configuration example. 
         FIG. 33  is a cross-sectional view illustrating a third variation of the fifth configuration example. 
         FIG. 34  is a cross-sectional view illustrating a fourth variation of the fifth configuration example. 
         FIG. 35  illustrates a set value of the height of a light-shielding wall. 
         FIG. 36  illustrates oblique incidence characteristics. 
         FIG. 37  illustrates the relationship between a pixel size and a protrusion amount. 
         FIG. 38  is a cross-sectional view illustrating a variation of the light-shielding wall. 
         FIG. 39  outlines a configuration example of a laminated solid-state imaging apparatus to which the technology according to the disclosure can be applied. 
         FIG. 40  is a cross-sectional view illustrating a first configuration example of a laminated solid-state imaging apparatus  23020 . 
         FIG. 41  is a cross-sectional view illustrating a second configuration example of the laminated solid-state imaging apparatus  23020 . 
         FIG. 42  is a cross-sectional view illustrating a third configuration example of the laminated solid-state imaging apparatus  23020 . 
         FIG. 43  is a cross-sectional view illustrating another configuration example of the laminated solid-state imaging apparatus to which the technology according to the disclosure can be applied. 
         FIG. 44  is a block diagram illustrating a configuration example of an imaging apparatus serving as an electronic appliance to which the present technology is applied. 
         FIG. 45  illustrates a usage example of an image sensor. 
         FIG. 46  is a block diagram illustrating one example of the schematic configuration of an in-vivo information acquisition system. 
         FIG. 47  illustrates one example of the schematic configuration of an endoscopic surgical system. 
         FIG. 48  is a block diagram illustrating examples of the functional configurations of a camera head and a CCU. 
         FIG. 49  is a block diagram illustrating one example of the schematic configuration of a vehicle control system. 
         FIG. 50  is an explanatory view illustrating examples of installation positions of a vehicle outside information detection portion and an imaging unit. 
     
    
    
     MODE FOR CARRYING OUT THE INVENTION 
     An embodiment for carrying out the present technology (hereinafter referred to as an embodiment) will be described below. Note that the description will be given in the following order. 
     1. Cross-sectional View of Entire Imaging Element 
     2. First Configuration Example of Imaging Element 
     3. Manufacturing Method in First Configuration Example 
     4. First Variation of First Configuration Example 
     5. Second Variation of First Configuration Example 
     6. Second Configuration Example of Imaging Element 
     7. Manufacturing Method in Second Configuration Example 
     8. First Variation of Second Configuration Example 
     9. Second Variation of Second Configuration Example 
     10. Third Configuration Example of Imaging Element 
     11. Manufacturing Method in Third Configuration Example 
     12. First Variation of Third Configuration Example 
     13. Second Variation of Third Configuration Example 
     14. Fourth Configuration Example of Imaging Element 
     15. Manufacturing Method in Fourth Configuration Example 
     16. Fifth Configuration Example of Imaging Element 
     17. Height of Light-Shielding Wall 
     18. Conclusion 
     19. Configuration Example of Solid-State Imaging Apparatus Applicable as Imaging Substrate 
     20. Example of Application to Electronic Appliance 
     21. Usage Example of Image Sensor 
     22. Example of Application to In-Vivo Information Acquisition System 
     23. Example of Application to Endoscopic Surgical System 
     24. Example of Application to Moving Object 
     1. Cross-sectional View of Entire Imaging Element 
       FIG. 1  is a cross-sectional view of an imaging element as an embodiment to which the present technology is applied. 
     An imaging element  1  illustrated in  FIG. 1  includes a chip-sized imaging substrate  11 . The imaging substrate  11  generates and outputs an imaging signal by photoelectrically converting incident light. The imaging element  1  has a chip size package (CSP) structure in which a cover glass  26  protects the upper-surface side that is a light incident surface of the imaging substrate  11 . In  FIG. 1 , light is incident downward from the upper side of the cover glass  26 , and the imaging substrate  11  receives the light. 
     A photoelectric conversion region  22  is formed on a surface on the side of the cover glass  26  on the imaging substrate  11 . The surface corresponds to the upper surface of a semiconductor substrate  21  including, for example, a silicon substrate. A photodiode PD ( FIG. 2 ) is formed for each pixel in the photoelectric conversion region  22 . The photodiode PD is a photoelectric conversion unit that photoelectrically converts incident light. Each pixel is two-dimensionally disposed in a matrix. An on-chip lens  23  is formed on a pixel basis on the upper surface of the semiconductor substrate  21 . The photoelectric conversion region  22  is formed on the upper surface. A flattening film  24  is formed on the upper side of the on-chip lens  23 . The cover glass  26  is bonded to the upper surface of the flattening film  24  via a glass seal resin  25 . 
     An imaging signal generated at the photoelectric conversion region  22  of the imaging substrate  11  is output from a through electrode  27  and rewiring  28 . The through electrode  27  penetrates the semiconductor substrate  21 . The rewiring  28  is formed on the lower surface of the semiconductor substrate  21 . A solder resist  29  covers a lower-surface region of the semiconductor substrate  21  other than a terminal unit including the through electrode  27  and the rewiring  28 . 
     Note that, although not illustrated, a plurality of pixel transistors and a multilayer wiring layer are formed on the lower-surface side of the semiconductor substrate  21 . The rewiring  28  is formed on the lower-surface side. The pixel transistors, for example, read a charge accumulated in the photodiode PD. The multilayer wiring layer includes a plurality of wiring layers and an interlayer insulating film. Consequently, the imaging element  1  in  FIG. 1  is a back-irradiation light receiving sensor that photoelectrically converts light incident from the back-surface side opposite to the front-surface side of the semiconductor substrate  21 . The multilayer wiring layer is formed on the front-surface side. 
     The terminal unit of the imaging substrate  11  is connected to a main substrate or an interposer substrate by, for example, a solder ball. The terminal unit includes the through electrode  27  and the rewiring  28 . The imaging element  1  is mounted in the main substrate. 
     The imaging element  1  configured as described above is a chip size package (CSP) of structure without a cavity. The structure has no void between the cover glass  26  and the imaging substrate  11 . The cover glass  26  protects the light incident surface (upper surface) of the imaging substrate  11 . For example, the flattening film  24  and the glass seal resin  25  fill the space between the cover glass  26  and the imaging substrate  11 . 
     Note that, although, in the embodiment, an example in which the cover glass  26  is used as a protective substrate for protecting the upper-surface side of the semiconductor substrate  21  will be described, for example, a light-transmitting resin substrate may be used instead of the cover glass  26 . 
     2. First Configuration Example of Imaging Element 
       FIG. 2  is a cross-sectional view illustrating a detailed first configuration example of the imaging element  1  in  FIG. 1 . 
       FIG. 2  illustrates a detailed configuration example of an upper part from the photoelectric conversion region  22  in  FIG. 1 . 
     In the photoelectric conversion region  22  of the semiconductor substrate  21 , a photodiode PD is formed for each pixel by, for example, forming an n-type (second conductive type) semiconductor region in a p-type (first conductive type) semiconductor region for each pixel. The photodiode PD is a photoelectric conversion unit that photoelectrically converts incident light. 
     An inter-pixel light-shielding film  50  is formed at a pixel boundary on the semiconductor substrate  21 . The inter-pixel light-shielding film  50  is only required to include a material that blocks light. For example, metal material such as aluminum (Al), tungsten (W), and copper (Cu) can be adopted as material having a strong light-shielding property and capable of being processed with good precision by microfabrication, for example, etching. Furthermore, a photosensitive (light-absorbing) resin containing a carbon black pigment and a titanium black pigment may be used as a material of the inter-pixel light-shielding film  50 . 
     A color filter layer (hereinafter referred to as a CF layer)  51  is formed for each pixel above the photodiode PD on the semiconductor substrate  21 . The inter-pixel light-shielding film  50  is not performed on the semiconductor substrate  21 . The CF layer  51  allows passage of incident light having a wavelength of red (R), green (G), or blue (B). Although, colors of R, G, and B are disposed in, for example, a Bayer array in the CF layer  51 , other complementary colors, such as cyan (Cy), magenta (Mg), and yellow (Ye), and arrangement methods, such as a transparent (clear) filter, may be used. 
     Note that an anti-reflection film may be formed on an interface on the back-surface side (upper side in the figure) of the semiconductor substrate  21 , and the inter-pixel light-shielding film  50  and the CF layer  51  may be formed on the anti-reflection film. The anti-reflection film includes, for example, a laminated film of a hafnium oxide (HfO 2 ) layer and a silicon oxide layer. 
     The on-chip lens (hereinafter referred to as the OCL)  23  is formed for each pixel on the CF layer  51 . The flattening film  24  is formed on the OCL  23 . The flattening film  24  is a light-transmitting layer that allows passage of incident light. 
     Furthermore, a light-shielding wall  52  is formed at a pixel boundary on the upper surface of the inter-pixel light-shielding film  50 . The light-shielding wall  52  separates the CF layer  51 , the OCL  23 , and the flattening film  24  on a pixel basis. In a similar manner to the inter-pixel light-shielding film  50 , a material of the light-shielding wall  52  can include metal material and a photosensitive (light-absorbing) resin. The metal material includes, for example, aluminum (Al) and tungsten (W). The photosensitive resin contains a carbon black pigment and a titanium black pigment. The light-shielding wall  52  is formed from the upper surface of the inter-pixel light-shielding film  50  to the same height as that of the flattening film  24 . Then, the glass seal resin  25  and the cover glass  26  are formed in the order on the light-shielding wall  52  and the flattening film  24 . The glass seal resin  25  is transparent, and joins the cover glass  26  to the imaging substrate  11  without a cavity. 
     For example, an organic material and an inorganic material are used as a material of the OCL  23  and the flattening film  24 . The organic material includes, for example, a styrene resin, an acrylic resin, a styrene-acrylic copolymer resin, and a siloxane resin. The inorganic material includes, for example, SiN and SiON. A material of each of the OCL  23  and the flattening film  24  is selected such that the flattening film  24  has a refractive index lower than that of the OCL  23 . For example, the styrene resin has a refractive index of approximately 1.6. The acrylic resin has a refractive index of approximately 1.5. The styrene-acrylic copolymer resin has a refractive index of approximately 1.5 to 1.6. The siloxane resin has a refractive index of approximately 1.45. SiN has a refractive index of approximately 1.9 to 2.0. SiON has a refractive index of 1.45 to 1.9. Furthermore, the refractive indices of the OCL  23  and the flattening film  24  are configured to be within a range of the refractive index of the cover glass  26  and the refractive index of the CF layer  51 . The cover glass  26  has a refractive index of approximately 1.45. The CF layer  51  has a refractive index of 1.6 to 1.7. 
     As described above, the light-shielding wall  52  is formed up to the position of the flattening film  24  above the photodiode PD of the photoelectric conversion region  22 . The light-shielding wall  52  is formed on the upper surface of the inter-pixel light-shielding film  50 . The flattening film  24  is placed above the CF layer  51 . Note that the inter-pixel light-shielding film  50  and the light-shielding wall  52  are omitted in the schematic view of the entire imaging element  1  in  FIG. 1 . 
     As illustrated in  FIG. 3 , in order to obtain incident light by cutting IR light, the imaging element  1  may have a configuration in which an IR cut filter  72  is disposed on the light incident side. The IR cut filter  72  is formed on a glass  71 . 
     Incident light is reflected on an interface of the semiconductor substrate  21  and the surface of the OCL  23  to be reflected light. The reflected light is re-reflected at the IR cut filter  72  or the cover glass  26 . In the above-described case, the re-reflected light is incident to the imaging element  1 , and can cause a flare and ghost. 
     The imaging element  1  reflects or absorbs light that is re-reflected at the cover glass  26  or the IR cut filter  72  and is again incident to the imaging element  1  by the light-shielding wall  52  that is higher than the CF layer  51  and that is formed up to the position of the upper surface of the flattening film  24 , so that the imaging element  1  can reduce false signal output called a flare and ghost. The imaging element  1  can be preferably used for, in particular, an apparatus that needs an imaging unit for receiving light having high intensity and being parallel, for example, an imaging unit and the like of an endoscope and a fundus examination apparatus. 
     3. Manufacturing Method in First Configuration Example 
     A method of manufacturing the imaging element  1  illustrated in  FIG. 2  in a first configuration example will be described with reference to  FIGS. 4 and 5 . 
     First, as illustrated in A of  FIG. 4 , the inter-pixel light-shielding film  50  is formed on a pixel boundary part on the upper surface on the back-surface side of the semiconductor substrate  21 . In the semiconductor substrate  21 , the photodiode PD is formed on a pixel basis. 
     Note that, in the process before forming the inter-pixel light-shielding film  50 , processes of forming a photodiode PD on a pixel basis on the back-surface side of the semiconductor substrate  21  and of forming a plurality of pixel transistors Tr and a multilayer wiring layer on the front-surface side of the semiconductor substrate  21  are performed. The transistors Tr read a charge accumulated in the photodiode PD, for example. The multilayer wiring layer includes a plurality of wiring layers and an interlayer insulating film. These processes are similar to those in a case of forming a common back-irradiation solid-state imaging element, and thus illustration and detailed description are omitted. 
     Next, as illustrated in B of  FIG. 4 , an insulating film  101  including, for example, SiO2 and the like is formed on the semiconductor substrate  21  including the inter-pixel light-shielding film  50 , and a predetermined part of the inter-pixel light-shielding film  50  is etched. As a result, as illustrated in C of  FIG. 4 , an opening  102  is formed for the light-shielding wall  52  to be formed. 
     Then, as illustrated in D of  FIG. 4 , filling material  103  such as tungsten (W) fills the interior of the opening  102  by, for example, sputtering, and serves as a film on the upper surface of the insulating film  101 . In a case where, for example, a photosensitive resin containing a carbon black pigment (hereinafter referred to as a carbon black resin) is used as a material of the light-shielding wall  52 , the carbon black resin serving as the filling material  103  is formed in the interior of the opening  102  and on the upper surface of the insulating film  101  by spin coating. 
     Thereafter, as illustrated in E of  FIG. 4 , the filling material  103  formed on the upper surface of the insulating film  101  is removed by chemical mechanical polishing (CMP) to form the light-shielding wall  52 . As illustrated in F of  FIG. 4 , the insulating film  101  is removed by, for example, wet etching. 
     Subsequently, as illustrated in A of  FIG. 5 , the CF layer  51  and the OCL  23  are formed on the upper surface of the photodiode PD. As illustrated in B of  FIG. 5 , the flattening film  24  is formed on the upper surface of the OCL  23  to have the same height as that of the light-shielding wall  52 . 
     Finally, as illustrated in C and D of  FIG. 5 , the upper surfaces of the flattening film  24  and the light-shielding wall  52  are coated with the glass seal resin  25 , and the cover glass  26  is joined to the glass seal resin  25 . 
     The imaging element  1  according to the first configuration example can be manufactured as described above. 
     Note that, in the imaging element  1 , for example, the inter-pixel light-shielding film  50 , the CF layer  51 , and the light-shielding wall  52 , which are formed on the upper surface of the semiconductor substrate  21 , can be disposed such that exit pupil correction is performed. 
       FIG. 6  illustrates disposition in a case where the imaging element  1  performs the exit pupil correction. 
     In a central region of a pixel array unit in which pixels are two-dimensionally disposed in a matrix, the incidence angle of a main light beam of incident light from an optical lens (not illustrated) is zero degrees, and thus the exit pupil correction is not performed. That is, as illustrated in B of  FIG. 6 , the CF layer  51 , the OCL  23 , and the flattening film  24 , which are formed on the upper surface of the semiconductor substrate  21 , are disposed so as to coincide with the center of the photodiode PD. 
     In contrast, in a region around the pixel array unit, the incidence angle of a main light beam of incident light from the optical lens is set to have a predetermined value in accordance with lens design, and thus the exit pupil correction is performed. That is, as illustrated in A of  FIG. 6 , the OCL  23 , the flattening film  24 , and the CF layer  51 , which are formed on the upper surface of the semiconductor substrate  21 , are disposed such that the centers of the OCL  23 , the flattening film  24 , and the CF layer  51  are shifted together with the light-shielding wall  52  from the center of the photodiode PD to the central side of the pixel array unit. This can further inhibit, for example, a reduction in sensitivity due to shading and leakage of incident light of an adjacent pixel in a pixel around the pixel array unit. 
     4. First Variation of First Configuration Example 
       FIG. 7  illustrates a first variation of the first configuration example illustrated in  FIG. 2 . 
     In  FIG. 7 , the same signs are attached to the parts corresponding to those in  FIG. 2 , and the description of the parts will be appropriately omitted. 
     In the first configuration example illustrated in  FIG. 2 , the light-shielding wall  52  formed on the inter-pixel light-shielding film  50  includes one type of material including, for example, metal material such as tungsten (W) and a carbon black resin. 
     In contrast, in the first variation in  FIG. 7 , the light-shielding wall  52  includes materials different in the upper part and the lower part. For example, a light-shielding wall  52 A includes metal material such as tungsten (W), and a light-shielding wall  52 B includes a carbon black resin. The light-shielding wall  52 A is a lower part of the light-shielding wall  52 . The light-shielding wall  52 B is an upper part of the light-shielding wall  52 . 
     In this way, the light-shielding wall  52  can include materials different in the upper part and the lower part. Note that, although a carbon black resin may be used as material of the lower light-shielding wall  52 A, and metal material such as tungsten (W) may be used as material of the upper light-shielding wall  52 B, a light-absorbing resin is more preferably used for the upper part. Furthermore, the material is not limited to two types. Three or more types of materials may be separately used in a height direction to form the light-shielding wall  52 . 
     5. Second Variation of First Configuration Example 
       FIG. 8  illustrates a second variation of the first configuration example illustrated in  FIG. 2 . 
     In  FIG. 8 , the same signs are attached to the parts corresponding to those in  FIG. 2 , and the description of the parts will be appropriately omitted. 
     In  FIG. 8 , the light-shielding wall  52  in the first configuration example illustrated in  FIG. 2  is replaced with a light-shielding wall  52 C. Other configurations in  FIG. 8  are similar to those in the first configuration example illustrated in  FIG. 2 . 
     The light-shielding wall  52  in the first configuration example illustrated in  FIG. 2  has the same thickness (thickness in a plane direction) from the bottom surface on which the light-shielding wall  52  is in contact with the inter-pixel light-shielding film  50  to the upper surface on which the light-shielding wall  52  is in contact with the glass seal resin  25 . 
     In contrast, in the second variation in  FIG. 8 , the light-shielding wall  52 C has a tapered shape in which the side surface is inclined. The light-shielding wall  52 C is thickest at the bottom surface on which the light-shielding wall  52 C is in contact with the inter-pixel light-shielding film  50 , and thinnest at the upper surface on which the light-shielding wall  52 C is in contact with the glass seal resin  25 . The light-shielding wall  52 C in plan view has a rectangular shape. The opening area inside the light-shielding wall  52 C is minimum at the bottom surface on the side of the CF layer  51 , and maximum at the upper surface on the side of the glass seal resin  25 . 
     In this way, the light-shielding wall  52 C having a tapered side surface enables the photodiode PD to capture much incident light, and can improve sensitivity. 
     In relation to the tapered light-shielding wall  52 C, the opening  102  can be tapered by controlling a dry etching condition at the time of forming the opening  102  in C of  FIG. 4 . The light-shielding wall  52 C is tapered by filling the tapered opening  102  with the filling material  103 . 
     Note that the light-shielding wall  52 C may include one type of material including metal material such as tungsten (W) and a carbon black resin, or as in the first variation, two or more types of materials may be separately used in the height direction. 
     6. Second Configuration Example of Imaging Element 
       FIG. 9  is a cross-sectional view illustrating a detailed second configuration example of the imaging element  1  in  FIG. 1 . 
     In  FIG. 9 , the same signs are attached to the parts corresponding to those in  FIG. 2 , and the description of the parts will be appropriately omitted. 
     In  FIG. 9 , the light-shielding wall  52  in the first configuration example illustrated in  FIG. 2  is replaced with a light-shielding wall  52 D. Other configurations in  FIG. 9  are similar to those in the first configuration example illustrated in  FIG. 2 . 
     While the light-shielding wall  52  in the first configuration example illustrated in  FIG. 2  has a flat side surface without unevenness, the light-shielding wall  52 D in  FIG. 9  has a side surface that is wavy (uneven) in cross-sectional view. 
     This causes light incident to the upper surface of the semiconductor substrate  21  to be dispersed and reflected as illustrated in B of  FIG. 10 , and thus the light intensity of reflected light is lowered in a case of the light-shielding wall  52 D having a wavy side surface as compared to the case of the flat light-shielding wall  52  illustrated in A of  FIG. 10 . Furthermore, as illustrated in  FIG. 11 , light incident to the light-shielding wall  52  is also dispersed and reflected, so that the light intensity of reflected light is lowered. 
     Consequently, according to the imaging element  1  according to the second configuration example, false signal output called a flare and ghost can be further reduced. 
     7. Manufacturing Method in Second Configuration Example 
       FIG. 12  illustrates a method of forming the wavy structure of the light-shielding wall  52 D. 
     In a case of forming a shape of a light-shielding wall with a resist, usually, processing of inhibiting a reflected wave from the semiconductor substrate  21  is performed by coating the upper and lower surfaces of the resist with anti-reflective-coating (ARC) and bottom-anti-refrective-coating (BARC) in order to reduce standing waves. A of  FIG. 12  illustrates the light-shielding wall shape of a resist formed by applying ARC and BRAC and inhibiting standing waves. 
     In contrast, in a case of forming the light-shielding wall  52 D having a wavy structure, the ARC and BRAC do not dare to be applied, and a standing wave is used. This enables the light-shielding wall  52 D to have a wall surface of a wavy structure as illustrated in B of  FIG. 12 . 
     A method of manufacturing the imaging element  1  illustrated in  FIG. 9  in the second configuration example will be described with reference to  FIGS. 13 and 14 . 
     In A of  FIG. 13 , in a manner similar to that in A of  FIG. 4  in the first configuration example, the inter-pixel light-shielding film  50  is formed at a pixel boundary part of the upper surface on the back-surface side of the semiconductor substrate  21  in which, for example, the photodiode PD and the multilayer wiring layer are formed. 
     Next, as illustrated in B of  FIG. 13 , the upper surface on the back-surface side of the semiconductor substrate  21  is coated with a resist  121 , and is exposed and developed with a mask  122  having a pattern corresponding to a position where the light-shielding wall  52 D is formed, whereby the resist  121  at a position other than the position where the light-shielding wall  52 D is formed is removed. In a case of applying the resist  121 , as described in  FIG. 12 , the upper and lower surfaces do not dare to be coated with the ARC and BRAC. This causes the resist  121  after development to have the same wavy structure as the light-shielding wall  52 D as illustrated in C of  FIG. 13 . For example, an organic material capable of withstanding a high temperature, such as “IX370G” manufactured by JSR Corporation can be used for the resist  121 . 
     Note that the resist  121  having a wavy structure can be formed in a tapered shape with inclination by controlling a light application condition in a case of performing exposure with the mask  122 . Consequently, the light-shielding wall  52 D having a wavy structure can be formed in a tapered shape as in the second variation of the first configuration example. 
     Next, as illustrated in D of  FIG. 13 , an insulating film  123  is formed with a thickness equal to or greater than the height of the resist  121 . The resist  121  is formed in a shape of a light-shielding wall. As illustrated in E of  FIG. 13 , the insulating film  123  is removed by CMP to the same height as that of the resist  121 . A low temperature oxide (LTO) film capable of being formed at a low temperature can be used as the insulating film  123 . 
     Next, as illustrated in F of  FIG. 13 , the resist  121  formed in the shape of a light-shielding wall is peeled off to form an opening  124  in the insulating film  123 . 
     The state of F of  FIG. 13  is the same as that in C of  FIG. 4  described in the manufacturing method in the first configuration example, except that the opening  124  has a wavy side surface. Subsequent processes are similar to those in the manufacturing method in the first configuration example. 
     That is, as illustrated in A of  FIG. 14 , the filling material  103  such as tungsten (W) fills the interior of the opening  124 , and serves as a film on the upper surface of the insulating film  123 . 
     Then, as illustrated in B of  FIG. 14 , the filling material  103  formed on the upper surface of the insulating film  123  is removed by CMP to form the light-shielding wall  52 D. As illustrated in C of  FIG. 14 , the insulating film  123  is removed by, for example, wet etching. 
     Subsequently, as illustrated in D of  FIG. 14 , the CF layer  51  and the OCL  23  are formed on the upper surface of the photodiode PD. As illustrated in E of  FIG. 14 , the flattening film  24 , the glass seal resin  25 , and the cover glass  26  are formed. 
     8. First Variation of Second Configuration Example 
       FIG. 15  illustrates a first variation of the second configuration example illustrated in  FIG. 9 . 
     Although the light-shielding wall  52 D has a wavy side surface in cross-sectional view in the above-described second configuration example, as illustrated in  FIG. 15 , a light-shielding wall  52 E may have a wavy (sawtooth) side surface in plan view. 
       FIG. 15  is a plan view illustrating the CF layer  51  and the light-shielding wall  52 E of the imaging element  1  according to the first variation of the second configuration example in 2×2=four-pixel regions. 
     In  FIG. 15 , the light-shielding wall  52 E has a sawtooth side surface in plan view, and each color of the CF layer  51  is disposed in a Bayer array. 
     In this way, effects similar to those of the light-shielding wall  52 D can be exhibited by the light-shielding wall  52 E having the sawtooth side surface in plan view. That is, as illustrated in  FIG. 16 , light incident to the light-shielding wall  52 E is dispersed and reflected, so that the light intensity of the reflected light can be lowered. This can reduce false signal output called a flare and ghost. 
     A of  FIG. 16  is a conceptual view illustrating how incident light is reflected on the light-shielding wall  52 E, which is illustrated in a perspective view. B of  FIG. 16  is a conceptual view illustrating how incident light is reflected on one recess of the light-shielding wall  52 E, which is enlarged in a plan view. 
     Note that the light-shielding wall  52 E may have a sawtooth side surface in plan view as illustrated in  FIGS. 15 and 16 , or may have a side surface having a wavy shape in which a corner of a change point of unevenness is rounded. The wavy shape includes a sawtooth shape. 
     A method of forming the light-shielding wall  52 E having a wavy (sawtooth) shape in plan view illustrated in  FIG. 15  will be described. 
     In the process, described in B and C of  FIG. 13 , of exposing and developing the resist  121  with the mask  122  and forming a pattern in the shape of the light-shielding wall  52 D, the light-shielding wall  52 E 
     having a wavy shape in plan view can be formed by making a pattern of the mask  122  in the same uneven shape as that of the plane pattern of the light-shielding wall  52 E illustrated in  FIG. 15 . Alternatively, the pattern of the mask  122  may be a plane pattern on which optical proximity correction (OPC) is performed as illustrated in  FIG. 17 . 
     9. Second Variation of Second Configuration Example 
       FIG. 18  illustrates a second variation of the second configuration example illustrated in  FIG. 9 . 
     Although the light-shielding wall  52 E has a wavy side surface in plan view in the first variation in  FIG. 15 , as illustrated in  FIG. 18 , a light-shielding wall  52 F may have a side surface having a repeated-arc shape. 
       FIG. 18  is a plan view illustrating the CF layer  51  and the light-shielding wall  52 F of the imaging element  1  according to the second variation of the second configuration example in 2×2=four-pixel regions. 
     In  FIG. 18 , the light-shielding wall  52 F has a side surface with a repeated-arc shape in plan view, and each color of the CF layer  51  is disposed in a Bayer array. 
     In this way, effects similar to those of the light-shielding wall  52 E can be exhibited by the light-shielding wall  52 F having the side surface with the repeated-arc shape in plan view. That is, light incident to the light-shielding wall  52 F is dispersed and reflected, so that the light intensity of the reflected light can be lowered. This can reduce false signal output called a flare and ghost. 
     Note that, although  FIG. 18  illustrates an example of the light-shielding wall  52 F having repeated projecting arcs inside a pixel, the light-shielding wall  52 F may have repeated projecting arcs outside the pixel. The wavy shape includes the repeated-arc shape. 
     A method of forming the light-shielding wall  52 F having the repeated-arc shape in plan view illustrated in  FIG. 18  will be described. 
     In the process, described in B and C of  FIG. 13 , of exposing and developing the resist  121  with the mask  122  and forming a pattern in the shape of the light-shielding wall  52 D, a binary mask is usually used as the mask  122 . In order to form the repeated-arc shape in  FIG. 18 , however, a halftone mask (phase difference shift mask) is used. 
     Specifically, the light-shielding wall  52 F having the repeated-arc shape in plan view can be formed by performing exposure and development with a halftone mask as illustrated in  FIG. 19 . In the halftone mask, a pattern is formed. In the pattern, rectangular openings are arranged at a predetermined pitch in accordance with the positions where the light-shielding walls  52 F are formed. 
     As described above, as in the first and second variations of the second configuration example, the light-shielding wall  52  having an uneven shape in plan view can reduce false signal output called a flare and ghost. 
     Note that, in a case of forming the light-shielding wall  52 E having a wavy shape in plan view and the light-shielding wall  52 F having a repeated-arc shape, if ARC and BARC are applied and reflected wave from the semiconductor substrate  21  is inhibited in the processes, corresponding to B and C in  FIG. 13 , of exposure and development, the light-shielding wall  52  having an uneven shape only in plan view can be formed. If ARC and BARC are not applied and a standing wave is used, the light-shielding wall  52  having an uneven shape in cross-sectional view and an uneven shape in plan view can be formed. 
     Although, in the examples illustrated in  FIGS. 15 and 18 , all pixels disposed in a Bayer array have a wavy or repeated-arc shape in plan view, only an R pixel among the R pixel, a G pixel, and a B pixel may has a wavy or repeated-arc shape in plan view as illustrated in A and B of  FIG. 20 . The R pixel receives light of R. The G pixel receives light of G. The B pixel receives light of B. The R pixel receives light having the longest wavelength. 
     A of  FIG. 20  is a plan view illustrating the light-shielding wall  52 E obtained by forming the light-shielding wall  52  in a sawtooth shape in plan view for only the R pixel. 
     B of  FIG. 20  is a plan view illustrating the light-shielding wall  52 F obtained by forming the light-shielding wall  52  in a repeated-arc shape in plan view for only the R pixel. 
     10. Third Configuration Example of Imaging Element 
       FIG. 21  is a cross-sectional view illustrating a detailed third configuration example of the imaging element  1  in  FIG. 1 . 
     In  FIG. 21 , the same signs are attached to the parts corresponding to those in  FIG. 2 , and the description of the parts will be appropriately omitted. 
     In  FIG. 21 , the light-shielding wall  52  in the first configuration example illustrated in  FIG. 2  is replaced with a light-shielding wall  52 G. Other configurations in  FIG. 21  are similar to those in the first configuration example illustrated in  FIG. 2 . 
     The light-shielding wall  52  in the first configuration example illustrated in  FIG. 2  has a height from the CF layer  51  to the upper surface of the flattening film  24 , that is, to the glass seal resin  25 . In contrast, the light-shielding wall  52 G in the third configuration example in  FIG. 21  has a height from the CF layer  51  to the upper surface of the glass seal resin  25 , that is, to the cover glass  26 . 
     This can further inhibit re-reflected light caused by reflected light of incident light re-reflecting on the IR cut filter  72  ( FIG. 3 ) or the cover glass  26  from being incident to the imaging element  1 , and reduce false signal output called a flare and ghost. 
     In a manner similar to that in the above-described first configuration example, a material of the light-shielding wall  52 G can include metal material and a photosensitive resin. The metal material includes, for example, aluminum (Al) and tungsten (W). The photosensitive resin contains a carbon black pigment and a titanium black pigment. 
     11. Manufacturing Method in Third Configuration Example 
     A method of manufacturing the imaging element  1  illustrated in  FIG. 21  in the third configuration example will be described with reference to  FIGS. 22 and 23 . 
     In A of  FIG. 22 , in a manner similar to that in A of  FIG. 4  in the first configuration example, the inter-pixel light-shielding film  50  is formed at a pixel boundary part of the upper surface on the back-surface side of the semiconductor substrate  21  in which, for example, the photodiode PD and the multilayer wiring layer are formed. 
     Next, as illustrated in B of  FIG. 22 , the CF layer  51  and the OCL  23  are formed on the upper surface of the photodiode PD. As illustrated in C of  FIG. 22 , the flattening film  24  is formed on the upper surface of the OCL  23 . 
     Subsequently, as illustrated in D of  FIG. 22 , the upper surfaces of the flattening film  24  and the light-shielding wall  52  are coated with the glass seal resin  25 . As illustrated in E of  FIG. 22 , the upper surface of the glass seal resin  25  is coated with a resist  151 , and patterned in accordance with the position where the light-shielding wall  52 G is formed. 
     Then, as illustrated in F of  FIG. 22 , an opening  152  is formed for the light-shielding wall  52 G to be formed by etching the glass seal resin  25  and the flattening film  24  until the inter-pixel light-shielding film  50  is exposed on the basis of the patterned resist  151 . 
     Then, as illustrated in A of  FIG. 23 , the filling material  103  such as tungsten and a carbon black resin fills the interior of the opening  152 , and serves as a film on the upper surface of the glass seal resin  25 . 
     Next, as illustrated in B of  FIG. 23 , the light-shielding wall  52 G is formed by removing the filling material  103  formed on the upper surface of the glass seal resin  25  by, for example, dry etching. In the state, the light-shielding wall  52 G has a height slightly lower than that of the glass seal resin  25 . 
     As illustrated in C of  FIG. 23 , the glass seal resin  25  is scraped by, for example, CMP to align the height of the glass seal resin  25  and that of the light-shielding wall  52 G. As illustrated in D of  FIG. 23 , the cover glass  26  is bonded. The imaging element  1  according to the third configuration example is completed. 
     Note that, as illustrated in E of  FIG. 23 , the cover glass  26  may be bonded with the height of the light-shielding wall  52 G being lower than that of the glass seal resin  25 . 
     In the imaging element  1  according to the third configuration example as well, the OCL  23 , the flattening film  24 , and the CF layer  51  are disposed such that the centers of the OCL  23 , the flattening film  24 , and the CF layer  51  are shifted together with the light-shielding wall  52  from the center of the photodiode PD to the central side of the pixel array unit in a region around the pixel array unit. This enables exit pupil correction. 
     12. First Variation of Third Configuration Example 
       FIG. 24  illustrates a first variation of the third configuration example illustrated in  FIG. 21 . 
     In  FIG. 24 , the same signs are attached to the parts corresponding to those in  FIG. 21 , and the description of the parts will be appropriately omitted. 
     In the third configuration example illustrated in  FIG. 21 , the light-shielding wall  52 G formed on the inter-pixel light-shielding film  50  include one type of material including, for example, metal material such as tungsten (W) and a carbon black resin. 
     In contrast, in the first variation in  FIG. 24 , the light-shielding wall  52 G includes materials different in the upper part and the lower part. For example, a light-shielding wall  52   g   1  includes metal material such as tungsten (W), and a light-shielding wall  52   g   2  includes a carbon black resin. The light-shielding wall  52   g   1  is a lower part of the light-shielding wall  52 G. The light-shielding wall  52   g   2  is an upper part of the light-shielding wall  52 G. 
     In this way, the light-shielding wall  52 G can include materials different in the upper part and the lower part. Note that, although a carbon black resin may be used as material of the lower light-shielding wall  52   g   1 , and metal material such as tungsten (W) may be used as material of the upper light-shielding wall  52   g   2 , a light-absorbing resin is more preferably used for the upper part. Furthermore, the material is not limited to two types. Three or more types of materials may be separately used in a height direction to form the light-shielding wall  52 . 
     13. Second Variation of Third Configuration Example 
       FIG. 25  illustrates a second variation of the third configuration example illustrated in  FIG. 21 . 
     In  FIG. 25 , the same signs are attached to the parts corresponding to those in  FIG. 21 , and the description of the parts will be appropriately omitted. 
     In  FIG. 25 , the light-shielding wall  52 G in the third configuration example illustrated in  FIG. 21  is replaced with a light-shielding wall  52 H. Other configurations in  FIG. 25  are similar to those in the third configuration example illustrated in  FIG. 21 . 
     The light-shielding wall  52 G in the third configuration example illustrated in  FIG. 21  has the same thickness (thickness in a plane direction) from the bottom surface on which the light-shielding wall  52 G is in contact with the inter-pixel light-shielding film  50  to the upper surface on which the light-shielding wall  52 G is in contact with the cover glass  26 . 
     In contrast, in the second variation in  FIG. 25 , the light-shielding wall  52 H has a tapered shape in which the side surface is inclined. The light-shielding wall  52 H is thickest at the bottom surface on which the light-shielding wall  52 H is in contact with the inter-pixel light-shielding film  50 , and thinnest at the upper surface on which the light-shielding wall  52 H is in contact with the cover glass  26 . The light-shielding wall  52 H in plan view has a rectangular shape. The opening area inside the light-shielding wall  52 H is minimum at the bottom surface on the side of the CF layer  51 , and maximum at the upper surface on the side of the cover glass  26 . 
     In this way, the light-shielding wall  52 H having a tapered side surface enables the photodiode PD to capture much incident light, and can improve sensitivity. 
     Note that the light-shielding wall  52 H may include one type of material including metal material such as tungsten (W) and a carbon black resin, or as in the first variation, two or more types of materials may be separately used in the height direction. 
     14. Fourth Configuration Example of Imaging Element 
       FIG. 26  is a cross-sectional view illustrating a detailed fourth configuration example of the imaging element  1  in  FIG. 1 . 
     In  FIG. 26 , the same signs are attached to the parts corresponding to the above-described other configuration examples, and the description of the parts will be appropriately omitted. 
     In  FIG. 26 , the light-shielding wall  52 G in the third configuration example illustrated in  FIG. 21  is replaced with a light-shielding wall  52 J. Other configurations in  FIG. 26  are similar to those in the third configuration example illustrated in  FIG. 21 . 
     While the light-shielding wall  52 G in the third configuration example illustrated in  FIG. 21  has a flat side surface without unevenness in cross-sectional view, the light-shielding wall  52 J in  FIG. 26  has a side surface that is wavy (uneven) in cross-sectional view. 
     The fourth configuration example and the second configuration example have a commonality in that the light-shielding wall  52 J in  FIG. 26  has a wavy side surface as compared to the second configuration example illustrated in  FIG. 9 . The fourth configuration example and the second configuration example are different in that, while the light-shielding wall  52 J in the fourth configuration example is formed from the CF layer  51  to the lower surface of the cover glass  26  (upper surface of the glass seal resin  25 ), the light-shielding wall  52 D in the second configuration example is formed from the CF layer  51  to a position of the upper surface of the flattening film  24  (lower surface of the glass seal resin  25 ). 
     Consequently, the fourth configuration example has the features of both the above-described second and third configuration examples, and exhibits the functions and effects of both thereof. That is, the light-shielding wall  52 J formed higher can further inhibit re-reflected light from being incident to the imaging element  1 . The light-shielding wall  52 J having a wavy side surface in cross-sectional view can further lower the light intensity of reflected light. 
     15. Manufacturing Method in Fourth Configuration Example 
     A method of manufacturing the imaging element  1  illustrated in  FIG. 26  in the fourth configuration example will be described with reference to  FIGS. 27 to 29 . 
     In A of  FIG. 27 , in a manner similar to that in A of  FIG. 4  in the first configuration example, the inter-pixel light-shielding film  50  is formed at a pixel boundary part of the upper surface on the back-surface side of the semiconductor substrate  21  in which, for example, the photodiode PD and the multilayer wiring layer are formed. 
     Next, as illustrated in B of  FIG. 27 , the CF layer  51  and the OCL  23  are formed on the upper surface of the photodiode PD. As illustrated in C of  FIG. 27 , the upper surface of the OCL  23  is coated with the resist  121 , and the resist  121  is exposed and developed with the mask  122  having a pattern corresponding to the position where the light-shielding wall  52 J is formed. As illustrated in D of  FIG. 27 , this operation removes the resist  121  at a position other than the position where the light-shielding wall  52 J is formed, and the resist  121  has the same wavy structure as the light-shielding wall  52 J. 
     Next, as illustrated in E of  FIG. 27 , the flattening film  24  is formed with a thickness equal to or greater than the height of the resist  121 . The resist  121  is formed in a shape of a light-shielding wall. As illustrated in F of  FIG. 27 , the flattening film  24  is removed by CMP to the same height as that of the resist  121 . 
     Next, as illustrated in A of  FIG. 28 , the resist  121  formed in the shape of a light-shielding wall is peeled off to form an opening  171  in the flattening film  24 . 
     Next, as illustrated in B of  FIG. 28 , the filling material  103  such as tungsten and a carbon black resin fills the interior of the opening  171 , and serves as a film on the upper surface of the flattening film  24 . 
     Then, as illustrated in C of  FIG. 28 , the filling material  103  formed on the upper surface of the flattening film  24  is removed by CMP to form a light-shielding wall  52 Ja, which is a part (lower part) of the light-shielding wall  52 J. 
     Subsequently, as illustrated in D of  FIG. 28 , the upper surfaces of the light-shielding wall  52 Ja and the insulating film  123  are coated with a resist  172 , and is exposed and developed with the mask  122  having a pattern corresponding to a position where the light-shielding wall  52 J is formed. As illustrated in E of  FIG. 28 , the resist  172  at a position other than the position where the light-shielding wall  52 J is formed is removed, and the resist  172  has a wavy structure as the light-shielding wall  52 J. For example, an organic material capable of withstanding a high temperature, such as “IX370G” manufactured by JSR Corporation can be used for the resist  172 . 
     Next, as illustrated in A of  FIG. 29 , the glass seal resin  25  is formed with a thickness equal to or greater than the height of the resist  172  formed in a shape of a light-shielding wall. As illustrated in B of  FIG. 29 , the resist  172  formed in the shape of a light-shielding wall is peeled off. An opening  173  is formed in the glass seal resin  25 . 
     Next, as illustrated in C of  FIG. 29 , filling material  174  such as tungsten and a carbon black resin fills the interior of the opening  173 , and serves as a film on the upper surface of the glass seal resin  25 . 
     Then, as illustrated in D of  FIG. 29 , the filling material  174  formed on the upper surface of the glass seal resin  25  is removed by CMP to form a light-shielding wall  52 Jb, which is the upper rest part of the light-shielding wall  52 J. The light-shielding wall  52 Ja and the light-shielding wall  52 Jb constitute the light-shielding wall  52 J. The light-shielding wall  52 Ja is formed in the same layer as that of the flattening film  24 . The light-shielding wall  52 Jb is formed in the same layer as that of the glass seal resin  25 . 
     Finally, as illustrated in E of  FIG. 29 , the cover glass  26  is bonded to the upper surfaces of the glass seal resin  25  and the light-shielding wall  52 J to complete the imaging element  1  according to the fourth configuration example. 
     16. Fifth Configuration Example of Imaging Element 
       FIG. 30  is a cross-sectional view illustrating a detailed fifth configuration example of the imaging element  1  in  FIG. 1 . 
     In  FIG. 30 , the same signs are attached to the parts corresponding to the first configuration example illustrated in  FIG. 2 , and the description of the parts will be appropriately omitted. 
     In  FIG. 30 , the OCL  23  formed between the CF layer  51  and the flattening film  24  in  FIG. 2  is omitted, and only the flattening film  24  is formed between the CF layer  51  and the glass seal resin  25 . Other configurations in  FIG. 30  are similar to those in the first configuration example illustrated in  FIG. 2 . In this way, the OCL  23  can be omitted since the light-shielding wall  52  has a role of an optical waveguide. 
     Note that not a material of the flattening film  24  but that of the OCL  23  may fill the space between the CF layer  51  and the glass seal resin  25 . Furthermore, the glass seal resin  25  may fill the space. That is, a light-transmitting layer is required to be made by one of materials of the OCL  23 , the flattening film  24 , and the glass seal resin  25  without forming a lens shape between the CF layer  51  and the glass seal resin  25 . The refractive index of the light-transmitting layer between the CF layer  51  and the glass seal resin  25  may be set between the refractive index of the cover glass  26  and that of the CF layer  51 . 
     The light-shielding wall  52  can include one type of material including, for example, metal material such as tungsten (W) and a carbon black resin. In addition, in a similar manner to that of the first variation of the first configuration example illustrated in  FIG. 7 , the light-shielding wall  52  may be formed by separately using materials different between the upper part and the lower part. 
     In the fifth configuration example as well, the light-shielding wall  52  formed higher than the CF layer  51  to the position of the upper surface of the flattening film  24  can reduce false signal output called a flare and ghost. 
     The configuration in which the OCL  23  is omitted can be applied to the above-described other configuration examples and variations. 
       FIG. 31  is a cross-sectional view illustrating a configuration in which the OCL  23  is omitted, the configuration being applied to the first variation of the first configuration example illustrated in  FIG. 7 . 
       FIG. 32  is a cross-sectional view illustrating the configuration in which the OCL  23  is omitted, the configuration being applied to the second variation of the first configuration example illustrated in  FIG. 8 . 
       FIG. 33  is a cross-sectional view illustrating the configuration in which the OCL  23  is omitted, the configuration being applied to the second configuration example illustrated in  FIG. 9 . 
       FIG. 34  is a cross-sectional view illustrating the configuration in which the OCL  23  is omitted, the configuration being applied to the third configuration example illustrated in  FIG. 21 . 
     Although illustration is omitted, the configuration in which the OCL  23  is omitted can be similarly applied to the first variation of the third configuration example illustrated in  FIG. 24 , the second variation of the third configuration example illustrated in  FIG. 25 , the fourth configuration example illustrated in  FIG. 26 , and variations thereof. 
     17. Height of Light-Shielding Wall 
     Next, a set value of the height of the light-shielding wall  52  will be described with reference to  FIG. 35 . 
     The light-shielding wall  52  formed higher than at least the CF layer  51  can reduce false signal output called as a flare and ghost. The light-shielding wall  52  formed at the same height as that of the OCL  23  or higher than the OCL  23  can further reduce the false signal output. 
     The height of the light-shielding wall  52  in a case of forming the light-shielding wall  52  higher than the OCL  23  can be determined in accordance with an incidence angle of incident light to be cut. Specifically, a protrusion amount Hs of the light-shielding wall  52  is calculated by Expression (1) below using an incidence angle θ and a pixel size Cs. As illustrated in  FIG. 35 , a protrusion amount of a part that protrudes to the upper side of the OCL  23  of the light-shielding wall  52  is defined as Hs, a pixel size is defined as Cs, and an incidence angle of incident light is defined as θ 1 . 
       Hs=(Cs/2)×tan(90−θ)  (1)
 
     An incidence angle to be cut is substituted into the incidence angle θ in Expression (1) above. For example, in a case of cutting incident light having an incidence angle of 60° or more, 60 is substituted into θ. 
       FIG. 36  illustrates oblique incidence characteristics indicating the relation between the incidence angle θ of incident light and output sensitivity for each color of R, G, and B. In  FIG. 36 , the light-shielding wall  52  is similar in height to the OCL  23 . 
     According to the oblique incidence characteristics in  FIG. 36 , output sensitivity is increased by a ghost component at incidence angles of 40 degrees or more. The incidence angles correspond to a part surrounded by a dashed line of R pixel. It can be seen that the light-shielding wall  52  needs to be made higher. 
     Furthermore, according to the oblique incidence characteristics in  FIG. 36 , it can be seen that the ghost component has a large influence on the R pixel among the R pixel, the G pixel, and the B pixel. Therefore, as illustrated in  FIG. 20 , a sufficient effect is exerted even in a case where only the R pixel has a structure of the light-shielding wall  52  having an uneven shape in plan view. 
       FIG. 37  illustrates the relation between the pixel size Cs and the protrusion amount Hs in a case where the incidence angle θ is set at 60 in Expression (1). As the pixel size Cs is increased, the protrusion amount Hs also needs to be increased. 
     Note that, as described above, the protrusion amount Hs of the light-shielding wall  52  is only required to secure at least an amount calculated in Expression (1) in accordance with the pixel size Cs and the incidence angle θ to be cut. Thus, a structure in which the uppermost surface of the light-shielding wall  52  is not in contact with the glass seal resin  25  as illustrated in  FIG. 38  is possible, for example. The structure as illustrated in  FIG. 38  is obtained in a case of forming the thick flattening film  24  and not aligning the height of the flattening film  24  with that of the light-shielding wall  52 . 
     18. Conclusion 
     As described above, the imaging element  1  in  FIG. 1  includes: a semiconductor substrate  21  including a photodiode PD for each pixel, the photodiode PD photoelectrically converting incident light; a CF layer  51  that is formed on the semiconductor substrate  21  and that passes the incident light of a predetermined wavelength; a light-shielding wall  52  that is formed at a pixel boundary on the semiconductor substrate  21  so as to have a height greater than that of the CF layer  51 ; and a cover glass  26  that is disposed via the glass seal resin  25  and that protects an upper-surface side of the CF layer  51 . 
     The light-shielding wall  52  formed higher than the CF layer  51  can reflect or absorb light that is re-reflected at the cover glass  26  or the IR cut filter  72  and is again incident to the imaging element  1 , and thus can reduce false signal output called a flare and ghost. 
     19. Configuration Example of Solid-State Imaging Apparatus Applicable as Imaging Substrate 
     A non-laminated solid-state imaging apparatus as described below and a laminated solid-state imaging apparatus including a plurality of laminated substrates can be applied as the above-described imaging substrate  11 . 
       FIG. 39  outlines a configuration example of a solid-state imaging apparatus applicable as the imaging substrate  11 . 
     A of  FIG. 39  illustrates a schematic configuration example of a non-laminated solid-state imaging apparatus. As illustrated in A of  FIG. 39 , a solid-state imaging apparatus  23010  has one die (semiconductor substrate)  23011 . A pixel region  23012 , a control circuit  23013 , and a logic circuit  23014  are mounted on the die  23011 . In the pixel region  23012 , pixels are disposed in an array. The control circuit  23013  drives the pixels, and performs various controls. The logic circuit  23014  processes a signal. 
     B and C of  FIG. 39  illustrate schematic configuration examples of a laminated solid-state imaging apparatus. As illustrated in B and C of  FIG. 14 , a solid-state imaging apparatus  23020  includes a sensor die  23021  and a logic die  23024 . The two dies are laminated and electrically connected to be one semiconductor chip. 
     In B of  FIG. 39 , the pixel region  23012  and the control circuit  23013  are mounted on the sensor die  23021 . The logic circuit  23014  is mounted on the logic die  23024 . The logic circuit  23014  includes a signal processing circuit that processes a signal. 
     In C of  FIG. 39 , the pixel region  23012  is mounted on the sensor die  23021 . The control circuit  23013  and the logic circuit  23014  are mounted on the logic die  23024 . 
       FIG. 40  is a cross-sectional view illustrating a first configuration example of the laminated solid-state imaging apparatus  23020 . 
     For example, a photodiode (PD) constituting a pixel that forms the pixel region  23012 , a floating diffusion (FD), a Tr (MOS FET), and a Tr that forms the control circuit  23013  are formed on the sensor die  23021 . Furthermore, a wiring layer  23101  is formed on the sensor die  23021 . The wiring layer  23101  includes wiring  23110  of a plurality of, three in the example, layers. Note that (Tr that forms) the control circuit  23013  can be configured not at the sensor die  23021  but at the logic die  23024 . 
     A Tr constituting the logic circuit  23014  is formed on the logic die  23024 . Furthermore, a wiring layer  23161  is formed on the logic die  23024 . The wiring layer  23161  includes wiring  23170  of a plurality of, three in the example, layers. Furthermore, a connection hole  23171  is formed in the logic die  23024 . An insulating film  23172  is formed on the inner wall surface of the connection hole  23171 . A connection conductor  23173  fills the connection hole  23171 . The connection conductor  23173  is connected to, for example, the wiring  23170 . 
     The sensor die  23021  and the logic die  23024  are stuck together such that the wiring layers  23101  and  23161  thereof face each other, and thereby the laminated solid-state imaging apparatus  23020  in which the sensor die  23021  and the logic die  23024  are laminated is configured. A film  23191  such as a protective film is formed on a surface where the sensor die  23021  and the logic die  23024  are stuck together. 
     A connection hole  23111  is formed in the sensor die  23021 . The connection hole  23111  penetrates the sensor die  23021  from the back-surface side (side where light is incident to a PD) (upper side) of the sensor die  23021  to reach the wiring  23170  of the uppermost layer of the logic die  23024 . Furthermore, a connection hole  23121  is formed in the sensor die  23021 . The connection hole  23121  comes close to the connection hole  23111 , and reaches the wiring  23110  of the first layer from the back-surface side of the sensor die  23021 . An insulating film  23112  is formed on the inner wall surface of the connection hole  23111 , and an insulating film  23122  is formed on the inner wall surface of the connection hole  23121 . Then, connection conductors  23113  and  23123  fill the connection holes  23111  and  23121 , respectively. The connection conductors  23113  and  23123  are electrically connected on the back-surface side of the sensor die  23021 , whereby the sensor die  23021  and the logic die  23024  are electrically connected via the wiring layer  23101 , the connection hole  23121 , the connection hole  23111 , and the wiring layer  23161 . 
       FIG. 41  is a cross-sectional view illustrating a second configuration example of the laminated solid-state imaging apparatus  23020 . 
     In the second configuration example of the solid-state imaging apparatus  23020 , one connection hole  23211  formed on the sensor die  23021  electrically connects the ((wiring  23110 ) of the wiring layer  23101  of) the sensor die  23021  and the ((wiring  23170 ) of the wiring layer  23161  of) the logic die  23024 . 
     That is, in  FIG. 41 , the connection hole  23211  is formed so as to penetrate the sensor die  23021  from the back-surface side of the sensor die  23021  to reach the wiring  23170  of the uppermost layer of the logic die  23024 , and to reach the wiring  23110  of the uppermost layer of the sensor die  23021 . An insulating film  23212  is formed on the inner wall surface of the connection hole  23211 , and a connection conductor  23213  fill the connection hole  23211 . In  FIG. 40  above, two connection holes  23111  and  23121  electrically connect the sensor die  23021  and the logic die  23024 , whereas, in  FIG. 41 , one connection hole  23211  electrically connects the sensor die  23021  and the logic die  23024 . 
       FIG. 42  is a cross-sectional view illustrating a third configuration example of the laminated solid-state imaging apparatus  23020 . 
     The solid-state imaging apparatus  23020  in  FIG. 42  is different from that in  FIG. 17  in that the film  23191  such as a protective film is not formed on a surface where the sensor die  23021  and the logic die  23024  are stuck together. In  FIG. 17 , the film  23191  such as a protective film is formed on a surface where the sensor die  23021  and the logic die  23024  are stuck together. 
     The solid-state imaging apparatus  23020  in  FIG. 42  is configured by overlapping the sensor die  23021  and the logic die  23024  such that the wiring  23110  and the wiring  23170  are brought into direct contact, heating the wiring  23110  and the wiring  23170  while applying predetermined weight, and directly joining the wiring  23110  and the wiring  23170 . 
       FIG. 43  is a cross-sectional view illustrating another configuration example of the laminated solid-state imaging apparatus to which the technology according to the disclosure can be applied. 
     In  FIG. 43 , a solid-state imaging apparatus  23401  has a three-layer laminated structure in which three dies of a sensor die  23411 , a logic die  23412 , and a memory die  23413  are laminated. 
     The memory die  23413  includes, for example, a memory circuit that stores data temporarily required in signal processing performed at the logic die  23412 . 
     Although, in  FIG. 43 , the logic die  23412  and the memory die  23413  are laminated under the sensor die  23411  in the order, the logic die  23412  and the memory die  23413  can be laminated under the sensor die  23411  in the opposite order, that is, the order of the memory die  23413  and the logic die  23412 . 
     Note that, in  FIG. 43 , a PD serving as a photoelectric conversion unit for a pixel and a source/drain region of a pixel Tr are formed in the sensor die  23411 . 
     A gate electrode is formed around the PD via a gate insulating film. Pixels Tr 23421  and Tr 23422  are formed by the gate electrode and a pair of source/drain regions. 
     The pixel Tr 23421  adjacent to the PD corresponds to a transfer Tr, and one of the pair of source/drain regions constituting the pixel Tr 23421  corresponds to the FD. 
     Furthermore, an interlayer insulating film is formed in the sensor die  23411 , and a connection hole is formed in the interlayer insulating film. A connection conductor  23431  connected to the pixel Tr 23421  and the pixel Tr 23422  is formed in the connection hole. 
     Moreover, a wiring layer  23433  is formed on the sensor die  23411 . The wiring layer  23433  includes wiring  23432  of a plurality of layers connected to each connection conductor  23431 . 
     Furthermore, an aluminum pad  23434  serving as an electrode for external connection is formed on the lowermost layer of the wiring layer  23433  of the sensor die  23411 . That is, in the sensor die  23411 , the aluminum pad  23434  is formed at a position closer to a bonding surface  23440  with the logic die  23412  than the wiring  23432 . The aluminum pad  23434  is used as one end of wiring related to input/output of a signal from/to the outside. 
     Furthermore, a contact  23441  used for electrical connection with the logic die  23412  is formed on the sensor die  23411 . The contact  23441  is connected to a contact  23451  of the logic die  23412  and also to an aluminum pad  23442  of the sensor die  23411 . 
     Then, a pad hole  23443  is formed in the sensor die  23411  so as to reach the aluminum pad  23442  from the back-surface side (upper side) of the sensor die  23411 . 
     The structure of a solid-state imaging apparatus as described above can be applied to the imaging substrate  11 . 
     20. Example of Application to Electronic Appliance 
     The technology according to the disclosure is not limited to application to a solid-state imaging apparatus. That is, the technology according to the disclosure can be applied to overall electronic appliances using a solid-state imaging apparatus in an image capturing unit (photoelectric conversion unit). The overall electronic appliances include, for example, imaging apparatuses such as digital still cameras and video cameras, mobile terminal apparatuses having an imaging function, and copying machines using a solid-state imaging apparatus in an image reading unit. The solid-state imaging apparatus may be formed in one chip or in a module having an imaging function. In the module, an imaging unit and a signal processing unit or an optical system are packaged together. 
       FIG. 44  is a block diagram illustrating a configuration example of an imaging apparatus as an electronic appliance to which the technology according to the disclosure is applied. 
     An imaging apparatus  300  in  FIG. 44  includes an optical unit  301 , a solid-state imaging apparatus (imaging device)  302 , and a digital signal processor (DSP) circuit  303 . The optical unit  301  includes, for example, a lens group. The solid-state imaging apparatus  302  adopts the configuration of the imaging element  1  in  FIG. 1 . The DSP circuit  303  is a camera signal processing circuit. Furthermore, the imaging apparatus  300  also includes a frame memory  304 , a display unit  305 , a recording unit  306 , an operation unit  307 , and a power supply unit  308 . The DSP circuit  303 , the frame memory  304 , the display unit  305 , the recording unit  306 , the operation unit  307 , and the power supply unit  308  are mutually connected via a bus line  309 . 
     The optical unit  301  captures incident light (image light) from a subject, and forms an image on an imaging surface of a solid-state imaging apparatus  302 . The solid-state imaging apparatus  302  converts an amount of incident light which forms an image on the imaging surface with the optical unit  301  into an electrical signal on a pixel basis, and outputs the electrical signal as a pixel signal. The imaging element  1  in  FIG. 1 , that is, an image sensor package that reduces false signal output due to reflected light of incident light can be used as the solid-state imaging apparatus  302 . 
     The display unit  305  includes, for example, a thin display such as a liquid crystal display (LCD) or an organic electro luminescence (EL) display, and displays a moving image or a still image captured by the solid-state imaging apparatus  302 . The recording unit  306  records a moving image or a still image captured by the solid-state imaging apparatus  302  in a recording medium such as a hard disk and a semiconductor memory. 
     The operation unit  307  issues an operation command for various functions of the imaging apparatus  300  under the operation of a user. The power supply unit  308  appropriately supplies various power supplies serving as operation power supplies for the DSP circuit  303 , the frame memory  304 , the display unit  305 , the recording unit  306 , and the operation unit  307  to these supply targets. 
     As described above, the CSP structure of the above-described imaging element  1  adopted as the solid-state imaging apparatus  302  can reduce false signal output due to reflected light of incident light. Consequently, the imaging apparatus  300  such as a video camera, a digital still camera, and a camera module for a mobile device such as a mobile phone can generate and output a high-quality image. 
     21. Usage Example of Image Sensor 
       FIG. 45  illustrates a usage example of an image sensor using the above-described imaging element  1 . 
     An image sensor using the above-described image sensor PKG 1  can be used in various cases of sensing light such as visible light, infrared light, ultraviolet light, and X-ray, for example, as described below.
         An apparatus that captures an image provided for viewing, such as a digital camera and a portable instrument with a camera function   An apparatus provided for traffic, such as an in-vehicle sensor, a monitoring camera, and a distance measurement sensor, the in-vehicle sensor capturing an image of, for example, the front, back, surroundings, and inside of an automobile for safe driving such as automatic stop, recognition of the state of a driver, and the like, the monitoring camera monitoring a running vehicle and a road, the distance measurement sensor measuring, for example, a distance between vehicles   An apparatus provided for a home electrical appliance such as a TV, a refrigerator, and an air conditioner for capturing an image of a gesture of a user and operating an instrument in accordance with the gesture   An apparatus provided for medical care and health care, such as an endoscope and an apparatus for capturing an image of a blood vessel by receiving infrared light   An apparatus provided for security, such as a monitoring camera for security and a camera for person authentication   An apparatus provided for beauty care, such as a skin measuring instrument for capturing an image of skin and a microscope for capturing an image of a scalp   An apparatus provided for sports, such as an action camera and a wearable camera for sports   An apparatus provided for agriculture, such as a camera for monitoring the states of a field and crops       

     22. Example of Application to In-Vivo Information Acquisition System 
     The technology (the present technology) according to the disclosure can be applied to various products as described above. For example, the technology according to the disclosure may be applied to a system for acquiring in-vivo information of a patient using a capsule endoscope. 
       FIG. 46  is a block diagram illustrating one example of the schematic configuration of a system for acquiring in-vivo information of a patient using a capsule endoscope, to which the technology according to the disclosure can be applied. 
     An in-vivo information acquisition system  10001  includes a capsule endoscope  10100  and an external control apparatus  10200 . 
     The capsule endoscope  10100  is swallowed by a patient at the time of examination. The capsule endoscope  10100  has an imaging function and a wireless communication function. The capsule endoscope  10100  sequentially captures an image (hereinafter also referred to an in-vivo image) of the interior of an organ, such as a stomach and intestines, at a predetermined interval while moving inside the organ by peristalsis until being naturally discharged from a patient. The capsule endoscope  10100  sequentially and wirelessly transmits information regarding the in-vivo image to the external control apparatus  10200  outside the body. 
     The external control apparatus  10200  comprehensively controls operations of the in-vivo information acquisition system  10001 . Furthermore, the external control apparatus  10200  receives information regarding an in-vivo image transmitted from the capsule endoscope  10100 , and generates image data for displaying the in-vivo image on a display (not illustrated) on the basis of the received information regarding the in-vivo image. 
     In this way, the in-vivo information acquisition system  10001  can acquire an in-vivo image obtained by imaging the interior of a patient from swallow to discharge of the capsule endoscope  10100  as needed. 
     The configurations and functions of the capsule endoscope  10100  and the external control apparatus  10200  will be described in more detail. 
     The capsule endoscope  10100  includes a capsule housing  10101 . In the housing  10101 , a light source unit  10111 , an imaging unit  10112 , an image processing unit  10113 , a wireless communication unit  10114 , a power feeding unit  10115 , a power supply unit  10116 , and a control unit  10117  are housed. 
     The light source unit  10111  includes a light source such as, for example, a light emitting diode (LED), and applies light to an imaging field of view of the imaging unit  10112 . 
     The imaging unit  10112  includes an imaging element and an optical system. The optical system includes a plurality of lenses provided in the front stage of the imaging element. Reflected light (hereinafter referred to as observation light) of light applied to a body tissue to be observed is received by the optical system, and is incident to the imaging element. In the imaging unit  10112 , observation light incident to an imaging element is photoelectrically converted, and an image signal corresponding to the observation light is generated. An image signal generated by the imaging unit  10112  is provided to the image processing unit  10113 . 
     The image processing unit  10113  includes a processor such as a central processing unit (CPU) or a graphics processing unit (GPU), and performs various types of signal processing on an image signal generated by the imaging unit  10112 . The image processing unit  10113  provides the image signal on which the signal processing is performed to the wireless communication unit  10114  as RAW data. 
     The wireless communication unit  10114  performs predetermined processing such as modulation processing on the image signal on which the signal processing is performed by the image processing unit  10113 , and transmits the image signal to the external control apparatus  10200  via an antenna  10114 A. Furthermore, the wireless communication unit  10114  receives a control signal related to drive control of the capsule endoscope  10100  from the external control apparatus  10200  via the antenna  10114 A. The wireless communication unit  10114  provides the control signal received from the external control apparatus  10200  to the control unit  10117 . 
     The power feeding unit  10115  includes, for example, an antenna coil for receiving power, a power regeneration circuit, and a booster circuit. The power regeneration circuit regenerates power from current generated in the antenna coil. The power feeding unit  10115  generates power by using, a so-called principle of non-contact charging. 
     The power supply unit  10116  includes a secondary battery, and stores power generated by the power feeding unit  10115 . In  FIG. 46 , for example, an arrow indicating a supply destination of power from the power supply unit  10116  is not illustrated to avoid the figure from being complicated. Power stored in the power supply unit  10116  can be supplied to the light source unit  10111 , the imaging unit  10112 , the image processing unit  10113 , the wireless communication unit  10114 , and the control unit  10117  to be used for driving these units. 
     The control unit  10117  includes a processor such as a CPU, and appropriately controls the drives of the light source unit  10111 , the imaging unit  10112 , the image processing unit  10113 , the wireless communication unit  10114 , and the power feeding unit  10115  in accordance with a control signal transmitted from the external control apparatus  10200 . 
     The external control apparatus  10200  includes, for example, a processor such as a CPU and a GPU, or a microcomputer or a control substrate in which a processor and a storage element such as a memory are mixedly mounted. The external control apparatus  10200  controls the operation of the capsule endoscope  10100  by transmitting a control signal to the control unit  10117  of the capsule endoscope  10100  via an antenna  10200 A. In the capsule endoscope  10100 , for example, a condition of light applied to an observation target in the light source unit  10111  can be changed by a control signal from the external control apparatus  10200 . Furthermore, an imaging condition (e.g., a frame rate, an exposure value, and the like in the imaging unit  10112 ) can be changed by a control signal from the external control apparatus  10200 . Furthermore, the content of processing in the image processing unit  10113  and a condition (e.g., transmission interval, the number of transmitted images, and the like) of the wireless communication unit  10114  transmitting an image signal may be changed by a control signal from the external control apparatus  10200 . 
     Furthermore, the external control apparatus  10200  performs various types of image processing on an image signal transmitted from the capsule endoscope  10100 , and generates image data for displaying a captured in-vivo image on a display. The image processing can include various types of signal processing such as, for example, development processing (demosaic processing), image quality improving processing (e.g., band emphasizing processing, super-resolution processing, noise reduction (NR) processing, and/or camera-shake correction processing), and/or enlargement processing (electronic zoom processing). The external control apparatus  10200  controls the drive of the display, and displays an in-vivo image captured on the basis of generated image data. Alternatively, the external control apparatus  10200  may cause a recording apparatus (not illustrated) to record the generated image data, or cause a printing apparatus (not illustrated) to print and output the generated image data. 
     One example of the in-vivo information acquisition system to which the technology according to the disclosure can be applied has been described above. The technology according to the disclosure can be applied to the imaging unit  10112  among the above-described configurations. Specifically, the above-described imaging element  1  can be applied as the imaging unit  10112 . The imaging unit  10112  to which the technology according to the disclosure is applied can reduce false signal output called a flare and ghost. The imaging unit  10112  can thus generate an in-vivo image with high quality, and contribute to improvement of examination precision. 
     23. Example of Application to Endoscopic Surgical System 
     The technology according to the disclosure may be applied to, for example, an endoscopic surgical system. 
       FIG. 47  illustrates one example of the schematic configuration of an endoscopic surgical system to which the technology according to the disclosure can be applied. 
     In  FIG. 47 , a surgeon (doctor)  11131  performs surgery on a patient  11132  on a patient bed  11133  by using an endoscopic surgical system  11000 . As illustrated in the figure, the endoscopic surgical system  11000  includes an endoscope  11100 , other surgical tools  11110  such as a pneumoperitoneum tube  11111  and an energy treatment tool  11112 , a support arm apparatus  11120 , and a cart  11200 . The support arm apparatus  11120  supports the endoscope  11100 . Various apparatuses for endoscopic surgery are mounted in the cart  11200 . 
     The endoscope  11100  includes a lens barrel  11101  and a camera head  11102 . A region, having a length predetermined from the distal end, of the lens barrel  11101  is inserted into a body cavity of the patient  11132 . The camera head  11102  is connected to the proximal end of the lens barrel  11101 . Although, in the illustrated example, the endoscope  11100 , which is configured as a so-called rigid mirror having the rigid lens barrel  11101 , is illustrated, the endoscope  11100  may be configured as a so-called flexible mirror having a flexible lens barrel. 
     An opening into which an objective lens is fitted is provided at the distal end of the lens barrel  11101 . A light source apparatus  11203  is connected to the endoscope  11100 . Light generated by the light source apparatus  11203  is guided to the distal end of the lens barrel by a light guide extending inside the lens barrel  11101 , and applied to an observation target in the body cavity of the patient  11132  via the objective lens. Note that the endoscope  11100  may be a forward-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope. 
     An optical system and an imaging element are provided inside the camera head  11102 . Reflected light (observation light) from the observation target is collected on the imaging element by the optical system. The observation light is photoelectrically converted by the imaging element, and an electrical signal corresponding to the observation light, that is, an image signal corresponding to the observation image is generated. The image signal is transmitted to a camera control unit (CCU)  11201  as RAW data. 
     The CCU  11201  includes, for example, a central processing unit (CPU) and a graphics processing unit (GPU), and comprehensively controls the operations of the endoscope  11100  and a display  11202 . Furthermore, the CCU  11201  receives an image signal from the camera head  11102 . The CCU  11201  performs various pieces of image processing for displaying an image based on the image signal on the image signal. The various pieces of image processing include, for example, development processing (demosaic processing) and the like. 
     The display  11202  displays an image based on the image signal on which image processing is performed by the CCU  11201  under the control of the CCU  11201 . 
     The light source apparatus  11203  includes a light source such as, for example, a light emitting diode (LED), and supplies irradiation light at the time of capturing an image of, for example, a surgical site to the endoscope  11100 . 
     An input apparatus  11204  is an input interface for the endoscopic surgical system  11000 . A user can input various pieces of information and instructions to the endoscopic surgical system  11000  via the input apparatus  11204 . For example, the user inputs, for example, an instruction to change an imaging condition (e.g., type of irradiation light, magnification, and focal length) in the endoscope  11100 . 
     A treatment tool control apparatus  11205  controls the drive of the energy treatment tool  11112  for, for example, tissue ablation, incision, and blood vessel sealing. In order to inflate the body cavity of the patient  11132  for securing a field of view for the endoscope  11100  and securing operation space for a surgeon, the pneumoperitoneum apparatus  11206  sends gas to the body cavity via the pneumoperitoneum tube  11111 . A recorder  11207  is an apparatus capable of recording various pieces of information regarding surgery. A printer  11208  is an apparatus capable of printing various pieces of information regarding surgery in various formats such as text, an image, and a graph. 
     Note that the light source apparatus  11203 , which supplies irradiation light at the time when the endoscope  11100  captures an image of a surgical site, can include, for example, an LED, a laser light source, or a white light source including a combination thereof. In a case where a combination of RGB laser light sources configures a white light source, the output intensity and output timing of each color (each wavelength) can be controlled with high precision. The light source apparatus  11203  thus can adjust white balance of a captured image. Furthermore, in the case, images corresponding to RGB can be captured in time division by applying laser light from each of RGB laser light sources to an observation target in time division and controlling the drive of an imaging element of the camera head  11102  in synchronization with the irradiation timing. According to the method, a color image can be obtained without providing a color filter in the imaging element. 
     Furthermore, the drive of the light source apparatus  11203  may be controlled so that the intensity of output light is changed every predetermined time. An image in a high dynamic range without a so-called black defect and halation can be generated by controlling the drive of the imaging element of the camera head  11102  in synchronization with the timing of change in the light intensity to acquire images in time division and combining the images. 
     Furthermore, the light source apparatus  11203  may be configured so as to supply light in a predetermined wavelength band, which can be used in special light observation. In the special light observation, for example, so-called narrow band imaging is performed. In the narrow band imaging, an image of a predetermined tissue such as a blood vessel in the surface layer of the mucous membrane is captured with high contrast by applying light in a band narrower than irradiation light (i.e., white light) at the time of an ordinary observation by using wavelength dependency of light absorption in a body tissue. Alternatively, in special light observation, fluorescence observation may be performed. In the fluorescence observation, an image is obtained by fluorescence generated by applying excitation light. In the fluorescence observation, for example, fluorescence from a body tissue can be observed by applying excitation light to the body tissue (autofluorescence observation). A fluorescent image can be obtained by locally injecting a reagent such as indocyanine green (ICG) and applying excitation light corresponding to the fluorescence wavelength of the reagent to the body tissue. The light source apparatus  11203  can be configured so as to supply narrowband light and/or excitation light, which can be used in such a special light observation. 
       FIG. 48  is a block diagram illustrating one example of the functional configurations of the camera head  11102  and the CCU  11201  illustrated in  FIG. 47 . 
     The camera head  11102  includes a lens unit  11401 , an imaging unit  11402 , a drive unit  11403 , a communication unit  11404 , and a camera head control unit  11405 . The CCU  11201  includes a communication unit  11411 , an image processing unit  11412 , and a control unit  11413 . The camera head  11102  and the CCU  11201  are connected so as to communication with each other by a transmission cable  11400 . 
     The lens unit  11401  is an optical system provided at a connection part with the lens barrel  11101 . Observation light captured from the distal end of the lens barrel  11101  is guided to the camera head  11102 , and is incident to the lens unit  11401 . The lens unit  11401  is configured by combining a plurality of lenses including a zoom lens and a focus lens. 
     The imaging unit  11402  includes an imaging element. One (so-called single-plate type) imaging element or a plurality of (so-called multi-plate type) imaging elements may constitute the imaging unit  11402 . In a case where the multi-plate type imaging unit  11402  is used, for example, each of imaging elements may generate image signals corresponding to each of RGB, and the image signals may be combined to obtain a color image. Alternatively, the imaging unit  11402  may include a pair of imaging elements, for acquiring image signals for a right eye and a left eye, which can be used in three-dimensional (3D) display. The 3D display enables the surgeon  11131  to more accurately grasp the depth of a biological tissue in a surgical site. Note that, in a case where the multi-plate type imaging unit  11402  is used, a plurality of lens units  11401  can be provided corresponding to each of the imaging elements. 
     Furthermore, the imaging unit  11402  is not necessarily provided in the camera head  11102 . For example, the imaging unit  11402  may be provided inside the lens barrel  11101  immediately after an objective lens. 
     The drive unit  11403  includes an actuator, and moves a zoom lens and a focus lens of the lens unit  11401  by a predetermined distance along an optical axis under the control of the camera head control unit  11405 . This enables the magnification and focus of a captured image obtained by the imaging unit  11402  to be appropriately adjusted. 
     The communication unit  11404  includes a communication apparatus for transmitting/receiving various types of information to/from the CCU  11201 . The communication unit  11404  transmits an image signal obtained from the imaging unit  11402  as RAW data to the CCU  11201  via the transmission cable  11400 . 
     Furthermore, the communication unit  11404  receives a control signal for controlling the drive of the camera head  11102  from the CCU  11201 , and supplies the control signal to the camera head control unit  11405 . The control signal includes information regarding an imaging condition such as, for example, information for specifying a frame rate of a captured image, information for specifying an exposure value at the time of imaging, and/or information for specifying a magnification and focus of the captured image. 
     Note that the above-described imaging conditions, such as the frame rate, exposure value, magnification, and focus, may be appropriately specified by a user, or may be automatically set by the control unit  11413  of the CCU  11201  on the basis of the acquired image signal. In the latter case, a so-called auto exposure (AE) function, auto focus (AF) function, and auto white balance (AWB) function are mounted in the endoscope  11100 . 
     The camera head control unit  11405  controls the drive of the camera head  11102  on the basis of a control signal, from the CCU  11201 , received via the communication unit  11404 . 
     The communication unit  11411  includes a communication apparatus for transmitting/receiving various types of information to/from the camera head  11102 . The communication unit  11411  receives an image signal transmitted via the transmission cable  11400  from the camera head  11102 . 
     Furthermore, the communication unit  11411  transmits a control signal for controlling the drive of the camera head  11102  to the camera head  11102 . The image signal and the control signal can be transmitted by, for example, electrical communication and optical communication. 
     The image processing unit  11412  performs various types of image processing on an image signal, which is RAW data, transmitted from the camera head  11102 . 
     The control unit  11413  performs various controls related to imaging of, for example, a surgical site with the endoscope  11100  and display of the captured image obtained by imaging of, for example, the surgical site. For example, the control unit  11413  generates a control signal for controlling the drive of the camera head  11102 . 
     Furthermore, the control unit  11413  causes the display  11202  to display a captured image in which, for example, a surgical site is reflected on the basis of the image signal on which image processing is performed by the image processing unit  11412 . At this time, the control unit  11413  may recognize various objects in the captured image by using various image recognition techniques. For example, the control unit  11413  can recognize, for example, a surgical tool such as forceps, a specific biological site, bleeding, and mist at the time of using the energy treatment tool  11112  by detecting, for example, the shape and color of an edge of an object in the captured image. At the time of displaying the captured image on the display  11202 , the control unit  11413  may superimpose and display various types of surgery support information on the image of the surgical site with reference to the recognition result. The superimposed and displayed surgery support information presented for the surgeon  11131  can reduce the burden on the surgeon  11131 , and enables the surgeon  11131  to reliably proceed with a surgery. 
     The transmission cable  11400 , which connects the camera head  11102  and the CCU  11201 , includes an electrical signal cable that can be used in electrical signal communication, an optical fiber that can be used in optical communication, or a composite cable thereof. 
     Although, in the example illustrated here, communication is performed by wire with the transmission cable  11400 , communication between the camera head  11102  and the CCU  11201  may be performed wirelessly. 
     One example of the endoscopic surgical system to which the technology according to the disclosure can be applied has been described above. The technology according to the disclosure can be applied to the imaging unit  11402  of the camera head  11102  among the above-described configurations. Specifically, the above-described imaging element  1  can be applied as the imaging unit  11402 . The imaging unit  11402  to which the technology according to the disclosure is applied can reduce false signal output called a flare and ghost. The imaging unit  11402  thus enables a surgeon to reliably check a surgical site. 
     Note that, although an endoscopic surgical system has been described here in one example, the technology according to the disclosure may be applied to another system such as, for example, a microscope surgery system. 
     24. Example of Application to Moving Object 
     Moreover, the technology according to the disclosure can be embodied as an apparatus mounted in a moving object of one of types such as, for example, an automobile, an electrical vehicle, a hybrid electrical vehicle, a motorcycle, a bicycle, a personal mobility, an airplane, a drone, a ship, and a robot. 
       FIG. 49  is a block diagram illustrating a schematic configuration example of a vehicle control system, which is one example of a moving object control system to which the technology according to the disclosure can be applied. 
     A vehicle control system  12000  includes a plurality of electronic control units connected via a communication network  12001 . In the example illustrated in  FIG. 49 , the vehicle control system  12000  includes a drive system control unit  12010 , a body system control unit  12020 , a vehicle outside information detection unit  12030 , a vehicle inside information detection unit  12040 , and an integrated control unit  12050 . Furthermore, a microcomputer  12051 , a voice image output unit  12052 , and an in-vehicle network interface (I/F)  12053  are illustrated as functional configurations of the integrated control unit  12050 . 
     The drive system control unit  12010  controls the operation of an apparatus related to a drive system of a vehicle in accordance with various programs. For example, the drive system control unit  12010  functions as a control apparatus for, for example, a driving force generation apparatus, a driving force transmission mechanism, a steering mechanism, and a braking apparatus. The driving force generation apparatus includes, for example, an internal combustion engine and a driving motor, and generates driving force for a vehicle. The driving force transmission mechanism transmits the driving force to a wheel. The steering mechanism adjusts the rudder angle of the vehicle. The braking apparatus generates braking force of the vehicle. 
     The body system control unit  12020  controls the operations of various apparatuses equipped in a vehicle body in accordance with various programs. For example, the body system control unit  12020  functions as a control apparatus for a keyless entry system, a smart key system, a power window apparatus, or various lamps. The lamps include, for example, a headlamp, a back lamp, a brake lamp, a blinker, and a fog lamp. In the case, a radio wave transmitted from a portable device substituted for a key or signals of various switches can be input in the body system control unit  12020 . The body system control unit  12020  receives the input of a radio wave or a signal, and controls, for example, a door lock apparatus, a power window apparatus, and a lamp of a vehicle. 
     The vehicle outside information detection unit  12030  detects information regarding the outside of a vehicle mounted with the vehicle control system  12000 . For example, an imaging unit  12031  is connected to the vehicle outside information detection unit  12030 . The vehicle outside information detection unit  12030  causes the imaging unit  12031  to capture an image outside the vehicle, and receives the captured image. The vehicle outside information detection unit  12030  may perform object detection processing or distance detection processing for a person, a vehicle, an obstacle, a sign, or a character on a road surface on the basis of the received image. 
     The imaging unit  12031  is an optical sensor that receives light and outputs an electrical signal corresponding to an amount of received light. The imaging unit  12031  can output an electrical signal as an image, or can also output information related to distance measurement. Furthermore, light received by the imaging unit  12031  may be visible light or invisible light such as infrared rays. 
     The vehicle inside information detection unit  12040  detects information regarding the inside of a vehicle. For example, a driver state detection unit  12041  is connected to the vehicle inside information detection unit  12040 . The driver state detection unit  12041  detects the state of a driver. The driver state detection unit  12041  includes, for example, a camera that images a driver. The vehicle inside information detection unit  12040  may calculate the degree of fatigue or concentration of the driver, or may determine whether or not the driver is asleep on the basis of detection information input from the driver state detection unit  12041 . 
     The microcomputer  12051  can calculate a control target value of the driving force generation apparatus, the steering mechanism, or the braking apparatus on the basis of information, regarding the inside/outside of a vehicle, acquired by the vehicle outside information detection unit  12030  or the vehicle inside information detection unit  12040 , and output a control command to the drive system control unit  12010 . For example, the microcomputer  12051  can perform cooperative control for achieving a function of an advanced driver assistance system (ADAS) including, for example, avoidance of vehicle collision or shock mitigation, following traveling based on a distance between vehicles, vehicle speed maintenance traveling, warning against vehicle collision, or warning against lane departure of a vehicle. 
     Furthermore, the microcomputer  12051  can perform cooperative control for, for example, automatic driving by controlling the driving force generation apparatus, the steering mechanism, the braking apparatus, or the like on the basis of information, regarding the surroundings of a vehicle, acquired at the vehicle outside information detection unit  12030  or the vehicle inside information detection unit  12040 . In the automatic driving, autonomous traveling is performed without depending on an operation of a driver. 
     Furthermore, the microcomputer  12051  can output a control command to the body system control unit  12020  on the basis of information, regarding the outside of a vehicle, acquired at the vehicle outside information detection unit  12030 . For example, the microcomputer  12051  can control a headlamp in accordance with the position of a preceding car or an oncoming car detected at the vehicle outside information detection unit  12030 , and perform cooperative control for preventing glare such as switching from high beam to low beam. 
     The voice image output unit  12052  transmits an output signal of at least one of sound or image to an output apparatus capable of visually or audibly notifying a vehicle occupant or vehicle outside of information. In the example of  FIG. 49 , an audio speaker  12061 , a display unit  12062 , and an instrument panel  12063  are illustrated as output apparatuses. For example, the display unit  12062  may include at least one of an on-board display or a head-up display. 
       FIG. 50  illustrates an example of an installation position of the imaging unit  12031 . 
     In  FIG. 50 , a vehicle  12100  includes imaging units  12101 ,  12102 ,  12103 ,  12104 , and  12105  as the imaging unit  12031 . 
     The imaging units  12101 ,  12102 ,  12103 ,  12104 , and  12105  are provided at a position of, for example, a front nose, a side mirror, a rear bumper, a back door, an upper part of a windshield in the vehicle interior, and the like of the vehicle  12100 . The imaging unit  12101  provided in the front nose and the imaging unit  12105  provided in the upper part of the windshield in the vehicle interior mainly acquire an image in front of the vehicle  12100 . The imaging units  12102  and  12103  provided in the side mirrors mainly acquire an image on the lateral side of the vehicle  12100 . The imaging unit  12104  provided in the rear bumper or the back door mainly acquires an image behind the vehicle  12100 . An image acquired by the imaging units  12101  and  12105  are mainly used for detecting, for example, a preceding vehicle, a pedestrian, an obstacle, a traffic light, a traffic sign, or a lane. 
     Note that  FIG. 50  illustrates one example of the image capturing ranges of the imaging units  12101  to  12104 . An imaging range  12111  indicates the imaging range of the imaging unit  12101  provided at the front nose. The imaging ranges  12112  and  12113  indicate the imaging ranges of the imaging units  12102  and  12103  provided at the side mirrors. The imaging range  12114  indicates the imaging range of the imaging unit  12104  provided at the rear bumper or the back door. For example, an overhead view in which the vehicle  12100  is seen from above can be obtained by superimposing pieces of data of images captured by the imaging units  12101  to  12104 . 
     At least one of the imaging units  12101  to  12104  may have a function of acquiring distance information. For example, at least one of the imaging units  12101  to  12104  may be a stereo camera including a plurality of imaging elements, or may be an imaging element having a pixel for phase difference detection. 
     For example, the microcomputer  12051  can extract a solid object as a preceding car by determining each distance to the solid object in the imaging ranges  12111  and  12114  and temporal change in the distance (relative speed with respect to the vehicle  12100 ) on the basis of the distance information obtained from the imaging units  12101  to  12104 . In particular, the solid object is closest to the vehicle  12100  in the advancing route, and travels at a predetermined speed (e.g., 0 km/h or more) in substantially the same direction as the vehicle  12100 . Moreover, the microcomputer  12051  can set a distance between vehicles to be preliminarily secured in front of the preceding car, and perform, for example, automatic brake control (including following stop control) and automatic acceleration control (following start control). In this way, cooperative control for, for example, automatic driving in which traveling is autonomously performed without depending on an operation of a driver can be performed. 
     For example, the microcomputer  12051  can classify solid object data regarding a solid object into a two-wheel vehicle, an ordinary vehicle, a large vehicle, a pedestrian, and other solid objects such as a utility pole and extract the data on the basis of distance information obtained from the imaging units  12101  to  12104 . The microcomputer  12051  can then use the data for automatic avoidance of an obstacle. For example, the microcomputer  12051  identifies obstacles around the vehicle  12100 , and divides the obstacles into obstacles that a driver of the vehicle  12100  can see and obstacles difficult to be seen. Then, the microcomputer  12051  determines a collision risk indicating the degree of risk of collision against each obstacle. In a situation where the collision risk is at a set value or more and collision may occur, the microcomputer  12051  outputs an alarm to the driver via the audio speaker  12061  or the display unit  12062 , and performs forced deceleration or avoidance steering via the drive system control unit  12010 . In such a way, the microcomputer  12051  can support driving to avoid a collision. 
     At least one of the imaging units  12101  to  12104  may be an infrared camera that detects infrared rays. For example, the microcomputer  12051  can recognize a pedestrian by determining whether or not a captured image from the imaging units  12101  to  12104  contains the pedestrian. Such pedestrian recognition is performed in, for example, an extraction procedure and a determination procedure. In the extraction procedure, feature points in captured images from the imaging units  12101  to  12104  serving as infrared cameras are extracted. In the determination procedure, whether or not an object is a pedestrian is determined by performing pattern matching processing on a series of feature points indicating the outline of the object. In a case where the microcomputer  12051  determines that the captured images from the imaging units  12101  to  12104  contain a pedestrian and recognizes the pedestrian, the voice image output unit  12052  controls the display unit  12062  so that a quadrangular outline for emphasis is superimposed and displayed on the recognized pedestrian. Furthermore, the voice image output unit  12052  may control the display unit  12062  so that, for example, an icon indicating a pedestrian is displayed at a desired position. 
     One example of the vehicle control system to which the technology according to the disclosure can be applied has been described above. The technology according to the disclosure can be applied to the imaging unit  12031  among the above-described configurations. Specifically, the above-described imaging element  1  can be applied as the imaging unit  12031 . The imaging unit  12031  to which the technology according to the disclosure is applied can reduce false signal output called a flare and ghost. The imaging unit  12031  can thus obtain a captured image easier to see, and contribute to improvement of safety of a vehicle. 
     Note that the effects described in the specification are merely examples and are not limitative, and effects other than those described in the specification may be exhibited. 
     Note that the present technology can also have the configurations as follows. 
     (1) 
     An imaging element including: 
     a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting incident light; 
     a color filter layer that is formed on the semiconductor substrate and that passes the incident light of a predetermined wavelength; 
     a light-shielding wall that is formed at a pixel boundary on the semiconductor substrate so as to have a height greater than a height of the color filter layer; and 
     a protective substrate that is disposed via a seal resin and that protects an upper-surface side of the color filter layer. 
     (2) 
     The imaging element according to (1), further including 
     an on-chip lens above the color filter layer, 
     in which the light-shielding wall is formed so as to have a same height as a height of the on-chip lens or a height greater than the height of the on-chip lens. 
     (3) 
     The imaging element according to (1) or (2), 
     in which the light-shielding wall is formed up to a height that reaches the seal resin. 
     (4) 
     The imaging element according to (1) or (2), 
     in which the light-shielding wall is formed up to a height that reaches the protective substrate. 
     (5) 
     The imaging element according to any one of (1) to (4), 
     in which the light-shielding wall is formed so as to be thinner in cross section toward an upper part. 
     (6) 
     The imaging element according to any one of (2) to (5), further including 
     a light-transmitting layer between the on-chip lens and the seal resin, the light-transmitting layer transmitting the incident light, 
     in which the light-transmitting layer has a refractive index lower than a refractive index of the on-chip lens. 
     (7) 
     The imaging element according to any one of (1) to (5), further including 
     a light-transmitting layer between the color filter layer and the seal resin, the light-transmitting layer transmitting the incident light, 
     in which the light-transmitting layer has a refractive index between a refractive index of the protective substrate and a refractive index of the color filter layer. 
     (8) 
     The imaging element according to any one of (1) to (7), 
     in which the light-shielding wall has a height at which the incident light having an incidence angle equal to or greater than a predetermined incidence angle is cut. 
     (9) 
     The imaging element according to (8), further including 
     an on-chip lens above the color filter layer, 
     in which a protrusion amount of the light-shielding wall is calculated in (pixel size/2)×tan (90−angle of the incident light desired to be cut), where a height of the light-shielding wall on an upper side of the on-chip lens is defined as the protrusion amount. 
     (10) 
     The imaging element according to any one of (1) to (9), further including 
     a pixel whose light-shielding wall is formed in an uneven shape in plan view. 
     (11) 
     The imaging element according to (10), 
     in which an R pixel is formed in the uneven shape. 
     (12) 
     The imaging element according to (10), 
     in which all pixels are formed in the uneven shape. 
     (13) 
     The imaging element according to any one of (10) to (12), 
     in which the uneven shape is a sawtooth shape. 
     (14) 
     The imaging element according to any one of (1) to (13), 
     in which the light-shielding wall has a wavy shape in cross-sectional view. 
     (15) 
     The imaging element according to any one of (1) to (14), 
     in which the light-shielding wall is formed by one or both of light absorbing material and metal material. 
     (16) 
     The imaging element according to (15), 
     in which the light-shielding wall is formed by both of light absorbing material and metal material, and 
     a lower part of the light-shielding wall is formed by the metal material, and an upper part is formed by the light absorbing material. 
     (17) 
     The imaging element according to (15) or (16), 
     in which the light absorbing material includes carbon black, and 
     the metal material includes tungsten. 
     (18) 
     A method of manufacturing an imaging element, including: 
     forming a color filter layer that passes incident light of a predetermined wavelength on a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting the incident light; 
     forming a light-shielding wall having a height greater than a height of the color filter layer at a pixel boundary on the semiconductor substrate; and 
     bonding a protective substrate on an upper side of the color filter layer via a seal resin. 
     (19) 
     An electronic appliance including 
     an imaging element that includes: 
     a semiconductor substrate including a photoelectric conversion unit for each pixel, the photoelectric conversion unit photoelectrically converting incident light; 
     a color filter layer that is formed on the semiconductor substrate and that passes the incident light of a predetermined wavelength; 
     a light-shielding wall that is formed at a pixel boundary on the semiconductor substrate so as to have a height greater than a height of the color filter layer; and 
     a protective substrate that is disposed via a seal resin and that protects an upper-surface side of the color filter layer. 
     REFERENCE SIGNS LIST 
     
         
           1  Imaging element 
           11  Imaging substrate 
         PD Photodiode 
           21  Semiconductor substrate 
           22  Photoelectric conversion region 
           23  On-chip lens (OCL) 
           24  Flattening film 
           25  Glass seal resin 
           26  Cover glass 
           50  Inter-pixel light-shielding film 
           51  Color filter layer (CF layer) 
         ( 52 A to  52 J) Light-shielding wall 
           300  Imaging apparatus 
           302  Solid-state imaging apparatus