Imaging element and imaging apparatus

Abstract

According to the present application, the sensitivity of an imaging element is improved. The imaging element includes a pixel and a light guide wall. Each pixel includes a photoelectric conversion unit arranged on a semiconductor substrate and performing photoelectric conversion on incident light, an on-chip lens that converges the incident light on the photoelectric conversion unit, a color filter that transmits incident light having a predetermined wavelength among the converged incident light, and an interlayer film arranged between the semiconductor substrate and the color filter. The light guide wall is arranged at a boundary of the pixel and is formed so that an end portion of the light guide wall is located in a recess portion that surrounds the pixel and guides the incident light, the recess portion being configured in a shape that surrounds the color filter and is formed in the interlayer film at the boundary of the pixel.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an imaging element and an imaging apparatus. More specifically, the present disclosure relates to an imaging element in which a plurality of pixels are arranged, and an imaging apparatus using the same. BACKGROUND

[0002] Conventionally, an imaging element in which a plurality of pixels that perform photoelectric conversion on incident light to generate an image signal are arranged has been used. In this imaging element, a color image signal can be generated by arranging a color filter that transmits incident light having a predetermined wavelength in the pixels. In an imaging element in which pixels provided with such a color filter are arranged, when light that has transmitted through the color filter corresponding to a different wavelength from an adjacent pixel is obliquely incident, image quality is degraded. This is because incident light mixed with a different wavelength from the incident light that has transmitted through the color filter arranged in the pixel, and color mixing is caused. In order to prevent such color mixing, an imaging element in which a partition wall is arranged at the boundary of the pixels to separate the color filters of adjacent pixels has been proposed. For example, an imaging element in which a first wall formed by sequentially stacking a light-blocking film that blocks incident light and a low-refractive film having a lower refractive index than the light-blocking film is arranged at the boundary of the pixels has been proposed (see, for example, Patent Literature 1).

[0003] In the above-described conventional technology, the low-refractive film of the first wall is configured to have a lower refractive index than the light-blocking film and the color filter, and can prevent the occurrence of color mixing by reflecting incident light from an adjacent pixel. On the other hand, it is expected that this low-refractive film has a function of guiding light incident to its own pixel to a semiconductor region that performs photoelectric conversion, and contributes to improving sensitivity.

[0004] [LIST OF CITATIONS]

[0005] [Patent Literature]

[0006] [Patent Literature 1] WO 2017 / 073321 SUMMARY

[0007] [TECHNICAL PROBLEM]

[0008] The above-described conventional technology has a problem that sensitivity is not sufficiently improved. The light-blocking film is arranged at the bottom of the above-described first wall. This light-blocking film is configured to have a relatively thick film thickness, and is arranged in a shape adjacent to the lower layer portion of the color filter. Therefore, light guided by the low-refractive film is blocked in the upper layer portion of the color filter, and incident light incident on the first wall of the lower layer of the color filter is absorbed by the light-blocking film. Therefore, there is a problem that sensitivity is not sufficiently improved.

[0009] The present disclosure was completed in view of the above-described problem, and aims to improve the sensitivity of an imaging element.

[0010] [Solution to the problem]

[0011] The present disclosure was completed in order to solve the above problems, and a first aspect thereof provides an imaging element including: pixels, each of the pixels including: a photoelectric conversion unit arranged in a semiconductor substrate to perform photoelectric conversion on incident light, an on-chip lens that converges the incident light on the photoelectric conversion unit, a color filter that transmits incident light having a predetermined wavelength among the converged incident light, and an interlayer film arranged between the semiconductor substrate and the color filter; and a light guide wall arranged at a boundary of the pixel and formed in a shape surrounding the color filter, the light guide wall having an end portion arranged in a recess surrounding the pixel to guide the incident light, the recess being formed in the interlayer film at the boundary of the pixel.

[0012] In the first aspect, the light guide wall can be formed of a member having a refractive index different from that of the color filter.

[0013] In the first aspect, the light guide wall can be formed of a member having a refractive index lower than that of the color filter.

[0014] In the first aspect, the light guide wall can be made of an oxide.

[0015] In the first aspect, the light guide wall can be made of a resin.

[0016] In the first aspect, the light guide wall can be formed of a void.

[0017] In the first aspect, the imaging element can further include: a separation portion arranged in the semiconductor substrate at the boundary of the pixel to separate the photoelectric conversion unit.

[0018] In the first aspect, the imaging element can further include: a light guide wall bottom film that is a film arranged at a bottom of the recess and adjacent to the light guide wall.

[0019] In the first aspect, the light guide wall bottom film can be further arranged on a side surface of the recess.

[0020] In the first aspect, the light guide wall bottom film can be a film that stops etching progress when the light guide wall is formed by etching.

[0021] In the first aspect, the light guide wall bottom film can be a film that blocks the incident light.

[0022] In the first aspect, the light guide wall bottom film can be a film that brings the light guide wall into close contact with the interlayer film.

[0023] In the first aspect, the light guide wall bottom film can be a film that prevents contaminants from moving to the semiconductor substrate.

[0024] In the first aspect, the light guide wall bottom film can be made of metal.

[0025] In the first aspect, the light guide wall bottom film can be made of silicon nitride.

[0026] In the first aspect, the light guide wall bottom film can be made of an oxide.

[0027] In the first aspect, the imaging element can further include a protective film disposed between the color filter and the light guide wall.

[0028] A second aspect of the present disclosure provides an imaging device including: pixels each including a photoelectric conversion unit disposed in a semiconductor substrate to perform photoelectric conversion on incident light, an on-chip lens that converges the incident light on the photoelectric conversion unit, a color filter that transmits incident light having a predetermined wavelength among the converged incident light, and an interlayer film disposed between the semiconductor substrate and the color filter; a light guide wall disposed at a boundary of the pixels and formed in a shape surrounding the color filter, the light guide wall having an end portion disposed in a recess surrounding the pixels to guide the incident light, the recess being formed in the interlayer film at the boundary of the pixels; and a processing circuit that processes an image signal generated based on the photoelectric conversion.

[0029] According to these aspects of the present disclosure, a light guide wall having a shape surrounding a portion of an interlayer film and a color filter is disposed. It is desirable to guide incident light in an area extending from the color filter to the portion of the interlayer film. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a diagram illustrating a configuration example of an imaging element according to an embodiment of the present disclosure.

[0031] Figure 2 is a diagram illustrating a configuration example of a pixel according to a first embodiment of the present disclosure.

[0032] Figure 3 is a diagram illustrating an example of a manufacturing method of an imaging element according to the first embodiment of the present disclosure.

[0033] Figure 4 is a diagram illustrating an example of a manufacturing method of an imaging element according to the first embodiment of the present disclosure.

[0034] Figure 5 is a diagram illustrating an example of a manufacturing method of an imaging element according to the first embodiment of the present disclosure.

[0035] Figure 6 FIG. 1 is a diagram showing an example of a manufacturing method of an imaging device according to a first embodiment of the present disclosure.

[0036] Figure 7 FIG. 2 is a diagram showing another example of a manufacturing method of an imaging device according to the first embodiment of the present disclosure.

[0037] Figure 8 FIG. 3 is a diagram showing another example of a manufacturing method of an imaging device according to the first embodiment of the present disclosure.

[0038] Figure 9 FIG. 4 is a diagram showing a configuration example of a light guide wall and a light guide wall bottom film according to a second embodiment of the present disclosure.

[0039] Figure 10 FIG. 5 is a diagram showing another configuration example of a light guide wall and a light guide wall bottom film according to the second embodiment of the present disclosure.

[0040] Figure 11 FIG. 6 is a diagram showing another configuration example of a light guide wall and a light guide wall bottom film according to the second embodiment of the present disclosure.

[0041] Figure 12 FIG. 7 is a diagram showing another configuration example of a light guide wall and a light guide wall bottom film according to the second embodiment of the present disclosure.

[0042] Figure 13 FIG. 8 is a diagram showing a configuration example of a pixel according to a third embodiment of the present disclosure.

[0043] Figure 14 FIG. 9 is a diagram showing a configuration example of a pixel according to a fourth embodiment of the present disclosure.

[0044] Figure 15 FIG. 10 is a diagram showing an example of a manufacturing method of an imaging device according to the fourth embodiment of the present disclosure.

[0045] Figure 16 FIG. 11 is a diagram showing an example of a manufacturing method of an imaging device according to the fourth embodiment of the present disclosure.

[0046] Figure 17 FIG. 12 is a diagram showing another example of a manufacturing method of an imaging device according to the fourth embodiment of the present disclosure.

[0047] Figure 18 FIG. 13 is a diagram showing a configuration example of a pixel according to a fifth embodiment of the present disclosure.

[0048] Figure 19 FIG. 14 is a block diagram showing a schematic configuration example of a camera as an example of an imaging apparatus to which the present technology is applicable. DETAILED DESCRIPTION

[0049] Next, embodiments for carrying out the present disclosure (hereinafter, referred to as embodiments) will be described with reference to the accompanying drawings. In the following drawings, the same or similar parts and symbols are denoted by the same or similar reference numerals and signs. In addition, the embodiments will be described in the following order.

[0050] 1. First Embodiment

[0051] 2. Second Embodiment

[0052] 3. Third Embodiment

[0053] 4. Fourth Embodiment

[0054] 5. Fifth Embodiment

[0055] 6. Application Example of Camera

[0056] <1. First Embodiment>

[0057] [Configuration of Imaging Element]

[0058] Figure 1 is a view showing a configuration example of an imaging element according to the embodiments of the present disclosure. In the view, the imaging element 1 includes a pixel array unit 10, a vertical drive unit 20, a column signal processing unit 30, and a control unit 40.

[0059] The pixel array unit 10 is configured with pixels 100 arranged in a two-dimensional lattice shape. Here, the pixels 100 generate image signals in response to irradiation light. Each pixel 100 has a photoelectric conversion unit that generates charges in response to irradiation light. In addition, each pixel 100 also has a pixel circuit. The pixel circuit generates an image signal based on the charges generated by the photoelectric conversion unit. The generation of the image signal is controlled by a control signal generated by the vertical drive unit 20 described later. Signal lines 11 and 12 are arranged in the pixel array unit 10 in an XY matrix shape. The signal line 11 is a signal line that transfers a control signal of the pixel circuit in the pixel 100, is arranged for each row of the pixel array unit 10, and is commonly wired for the pixels 100 arranged in each row. The signal line 12 is a signal line that transfers an image signal generated by the pixel circuit of the pixel 100, is arranged for each column of the pixel array unit 10, and is commonly wired for the pixels 100 arranged in each column. The photoelectric conversion unit and the pixel circuit are formed on a semiconductor substrate.

[0060] The vertical drive unit 20 generates a control signal of a pixel circuit of the pixel 100. The vertical drive unit 20 transmits the generated control signal to the pixel 100 through a signal line 11 in the drawing. The column signal processing unit 30 processes an image signal generated by the pixel 100. The column signal processing unit 30 processes the image signal transmitted from the pixel 100 through a signal line 12 in the drawing. The processing in the column signal processing unit 30 corresponds to, for example, analog-digital conversion of converting an analog image signal generated in the pixel 100 into a digital image signal. The image signal processed by the column signal processing unit 30 is output as an image signal of the imaging device 1. The control unit 40 controls the entire imaging device 1. The control unit 40 generates and outputs a control signal for controlling the vertical drive unit 20 and the column signal processing unit 30 to control the imaging device 1. The control signal generated by the control unit 40 is transmitted to the vertical drive unit 20 and the column signal processing unit 30 through signal lines 41 and 42.

[0061] [Pixel Configuration]

[0062] Figure 2 is a drawing illustrating a configuration example of a pixel according to the first embodiment of the present disclosure. The drawing is a schematic cross-sectional view illustrating a configuration example of the pixel 100. The pixel 100 includes a semiconductor substrate 110, a wiring region 120, a separation portion 130, an interlayer film 132, a color filter 140, an on-chip lens 170, a light guide wall 160, and a light guide wall bottom film 150.

[0063] The semiconductor substrate 110 is a semiconductor substrate on which a diffusion region of an element of a photoelectric conversion unit and a pixel circuit is formed. The semiconductor substrate 110 can be formed of, for example, silicon (Si). The diffusion region of the element of the photoelectric conversion unit and the pixel circuit can be arranged in a well region formed on the semiconductor substrate 110. For convenience, it is assumed that the semiconductor substrate 110 in the drawing constitutes a p-type well region. By arranging an n-type semiconductor region in the p-type well region, a diffusion region of an element of a photoelectric conversion unit or the like can be formed. In the drawing, a photoelectric conversion unit 101 is illustrated as an example of the element. The photoelectric conversion unit 101 is formed of an n-type semiconductor region 111 arranged in the p-type well region. Specifically, a photodiode formed of a pn junction between the n-type semiconductor region 111 and the p-type well region around the n-type semiconductor region 111 corresponds to the photoelectric conversion unit 101. In the semiconductor substrate 110, the separation portion 130 described later is arranged at a boundary portion of the pixel 100.

[0064] The wiring region 120 is a region arranged on the front surface side of the semiconductor substrate 110, and in which a wiring for transmitting a signal or the like to an element of the pixel circuit is formed. The wiring region 120 includes a wiring layer 122 and an insulating layer 121. The wiring layer 122 is a wiring for transmitting a signal or the like to an element of the pixel circuit. The wiring layer 122 can be made of a metal such as copper (Cu), tungsten (W), or aluminum (Al). The insulating layer 121 insulates the wiring layer 122. The insulating layer 121 can be made of an insulating material such as silicon oxide (SiO2) or silicon nitride (SiN).

[0065] The separation portion 130 is arranged in the semiconductor substrate 110 to separate the pixels 100. The separation portion 130 is arranged in a groove 131 formed at a boundary of the pixel 100 of the semiconductor substrate 110. The separation portion 130 can be made of an insulating material such as SiO2, for example. The separation portion 130 can be made of a metal such as W. When the separation portion 130 made of a metal is arranged, an insulating film for insulating the semiconductor substrate 110 and the separation portion 130 in the groove 131 can be arranged. By arranging the separation portion 130, it is possible to prevent charges generated by the photoelectric conversion unit 101 of the pixel 100 from moving to an adjacent pixel 100, and it is possible to prevent noise from mixing into an image signal. The separation portion 130 in the drawing shows an example in which it is configured in a shape in which it is arranged in the groove 131 formed from the back surface side of the semiconductor substrate 110 and the bottom reaches near the front surface side of the semiconductor substrate 110. The separation portion 130 can also be configured in a shape that penetrates the semiconductor substrate 110. The separation portion 130 can be arranged in a groove formed from the front surface side of the semiconductor substrate 110.

[0066] The interlayer film 132 is a film arranged on the back surface side of the semiconductor substrate 110 to protect the semiconductor substrate 110. The interlayer film 132 fixes and protects the back surface side of the semiconductor substrate 110, and also prevents contaminants from diffusing into the semiconductor substrate 110 from the color filter 140 or the like described later. The interlayer film 132 can be made of an insulating material such as SiO2, for example. The interlayer film 132 can be configured to have a thickness of 200 nm to 300 nm. By arranging the interlayer film 132 having a relatively thick film thickness in this way, it is possible to suppress the diffusion of contaminants into the semiconductor substrate 110, and to prevent the occurrence of contamination. A portion of the light guide wall 160 described later is arranged on the interlayer film 132 at the boundary of the pixel 100.

[0067] The color filter 140 is an optical filter that transmits incident light having a predetermined wavelength among the incident light of the pixel 100. The color filter 140 is arranged adjacent to the interlayer film 132. As the color filter 140, three types of color filters 140 that transmit red light, green light, and blue light can be used. One of these three types of color filters 140 can be arranged in each pixel 100.

[0068] The on-chip lens 170 is a lens arranged for each pixel 100 to converge incident light on the photoelectric conversion unit 101. The on-chip lens 170 is configured in a semispherical shape to converge incident light. The on-chip lens 170 can be made of an inorganic material such as SiN or an organic material such as acrylic resin. The on-chip lens 170 in the figure is arranged adjacent to the color filter 140.

[0069] The imaging element in the figure corresponds to a back-illuminated type imaging element in which the back surface side of the semiconductor substrate 110 is irradiated with incident light.

[0070] The light guide wall 160 is arranged at the boundary of the pixel 100 to guide incident light that has passed through the on-chip lens 170 to the semiconductor substrate 110. The light guide wall 160 is configured in a shape that surrounds the color filter 140. That is, the light guide wall 160 is arranged in the groove 168 formed at the boundary of the pixel 100 and is configured in a cylindrical shape. The light guide wall 160 is configured in a shape in which the end portion thereof is embedded in the interlayer film 132. Specifically, the end portion of the light guide wall 160 is arranged in the recessed portion 169 in the interlayer film 132 arranged at the boundary of the pixel 100.

[0071] Since incident light that is normally incident on the pixel 100 is converged on the central portion of the pixel 100 by the on-chip lens 170, it reaches the photoelectric conversion unit 101 without reaching the light guide wall 160. On the other hand, incident light that is obliquely incident on the pixel 100 is reflected by the light guide wall 160 and is incident on the photoelectric conversion unit 101. The arrows in the figure indicate incident light components 401 and 402 that are obliquely incident on the pixel 100. These two incident light components 401 and 402 are reflected at the interface of the light guide wall 160 and are incident on the photoelectric conversion unit 101. The incident light 401 indicates incident light that is reflected by the light guide wall 160 adjacent to the color filter 140, and the incident light 402 indicates incident light that is reflected by the light guide wall 160 adjacent to the interlayer film 132. In this way, the light guide wall 160 can guide obliquely incident light to the photoelectric conversion unit 101 while reflecting it.

[0072] As described later Figure 19In the above-described imaging device such as a camera, light from an object is converged on a pixel array unit 10 of an imaging element 1 through a photographing lens that forms an object image. Light from the object is substantially perpendicularly incident on a pixel 100 arranged at the center of the pixel array unit 10. On the other hand, light from the object is obliquely incident on the pixel 100 arranged on the peripheral edge of the pixel array unit 10. When the light guide wall 160 is not arranged, the obliquely incident light is incident on a photoelectric conversion unit 101 of an adjacent pixel 100 after passing through the color filter 140, thereby causing color mixing. Here, the color mixing is a phenomenon in which noise is mixed in an image signal due to the influence of incident light that has passed through a color filter 140 of a different type from the color filter 140 arranged in the own pixel 100. In order to prevent the occurrence of such color mixing, pupil correction is performed in which the on-chip lens 170 and the color filter 140 are arranged to be shifted toward the center of the pixel array unit 10.

[0073] As described above, by arranging the light guide wall 160 on the pixel 100, obliquely incident light can be reflected in the direction of the semiconductor substrate 110. Since the occurrence of color mixing can be suppressed, there is no need to employ pupil correction in the pixel 100 in the drawing.

[0074] The light guide wall 160 is arranged in a region extending from the color filter 140 to the interlayer film 132. By forming the bottom of the recess 169 of the interlayer film 132 to a shape reaching the vicinity of the back surface of the semiconductor substrate 110, the bottom of the light guide wall 160 can be brought close to the junction of the interlayer film 132 and the semiconductor substrate 110. The light guide wall 160 is configured to have a shape extending from a light receiving end of the incident light of the color filter 140 at the boundary of the pixel 100 to the vicinity of the junction surface of the interlayer film 132 and the semiconductor substrate 110. Thus, the incident light can be guided from the color filter 140 to the vicinity of the semiconductor substrate 110 seamlessly using the light guide wall 160. Leakage and absorption of the incident light from the side surface of the pixel 100 can be suppressed, and the sensitivity of the pixel 100 can be improved. Even when the interlayer film 132 having a relatively thick film thickness is arranged, the incident light can be guided to the semiconductor substrate 110.

[0075] The light guide wall 160 can be formed of a member having a refractive index different from that of the color filter 140. For example, the light guide wall 160 can be made of an oxide such as SiO2or a resin. Further, it is preferable that the light guide wall 160 be formed of a member having a refractive index lower than that of the color filter 140. This is because an optical waveguide is formed with the color filter 140 and the light guide wall 160 as a core and a cladding, respectively, and the incident light that has passed through the light guide wall 160 can be reduced. The light guide efficiency of the incident light can be further improved.

[0076] As described above, the light guide wall 160 is configured in a cylindrical shape around the color filter 140 or the like. For example, the light guide wall 160 can be formed by arranging a material film of the light guide wall 160 on the back surface side of the semiconductor substrate 110 before the color filter 140 is arranged and etching the material film present at a position other than the boundary of the pixel 100. After that, the pixel 100 can be formed by arranging the color filter 140 inside the cylindrical light guide wall 160.

[0077] Further, the light guide wall 160 can be formed, for example, by arranging the color filter 140, then etching the color filter 140 at the boundary portion of the pixel 100 to form the groove 168, and embedding a material of the light guide wall 160 in the groove 168.

[0078] The light guide wall bottom film 150 is a film arranged at the bottom of the recessed portion 169 of the interlayer film 132. The light guide wall bottom film 150 is arranged adjacent to the light guide wall 160. The light guide wall bottom film 150 in the drawing shows an example in which it is arranged at the bottom and side of the recessed portion 169. An etching stopper film can be applied to the light guide wall bottom film 150. Here, the etching stopper is a substance that stops the progress of etching.

[0079] As described above, the light guide wall 160 can be formed by etching a material film of the light guide wall 160. The light guide wall bottom film 150 can be arranged as a film for stopping the progress of etching of the material film of the light guide wall 160 in this etching process. Specifically, the light guide wall bottom film 150 formed of a member having high selectivity with respect to the material film of the light guide wall 160, that is, a member having a lower etching rate than the material film of the light guide wall 160 is arranged on the surface of the interlayer film 132 in which the recessed portion 169 is formed. Next, the material film of the light guide wall 160 is laminated on the light guide wall bottom film 150, and the material film of the light guide wall 160 present at a position other than the boundary of the pixel 100 is etched. At this etching, the progress of etching is stopped by the light guide wall bottom film 150 arranged below the material film of the light guide wall 160. Thus, it is possible to prevent the interlayer film 132 from being damaged due to over-etching.

[0080] Further, by arranging the light guide wall bottom film 150 having the etching stopper function, it is possible to easily adjust the etching depth and stabilize the shape of the region to be etched. Such a light guide wall bottom film 150 can be made of, for example, metal or SiN.

[0081] Further, a film that blocks incident light can be applied to the light guide wall bottom film 150. As a result, it is possible to prevent incident light and the like that has passed through the end portion of the on-chip lens 170 and passed through the inside of the light guide wall 160 from entering the semiconductor substrate 110. Thus, it is possible to prevent the occurrence of flare. Such a light guide wall bottom film 150 can be made of, for example, metal such as W or Al.

[0082] Further, a film that brings the light guide wall 160 into close contact with the interlayer film 132 can be applied to the light guide wall bottom film 150. When the light guide wall 160 is formed as described above, the color filter 140 is disposed after the cylindrical light guide wall 160 is formed on the surface of the interlayer film 132. This can be performed, for example, by coating a material of the color filter 140. If the adhesion strength between the light guide wall bottom film 150 and the light guide wall 160 is insufficient, the light guide wall 160 can be damaged when the color filter 140 or the like is formed. Therefore, by disposing the light guide wall bottom film 150 having high adhesion strength on both the interlayer film 132 and the light guide wall 160, damage to the light guide wall 160 can be prevented. Such a light guide wall bottom film 150 can be made of, for example, SiO2.

[0083] Further, a film that prevents contaminants from moving to the semiconductor substrate 110 can be applied to the light guide wall bottom film 150. When contaminants from the light guide wall 160 or the like diffuse into the semiconductor substrate 110, contamination occurs and affects the image signal. Further, contaminants such as metals included in the color filter 140 can diffuse into the semiconductor substrate 110 through the light guide wall 160. Therefore, the light guide wall bottom film 150 that functions as a contaminant barrier layer is disposed to prevent diffusion of contaminants. As a result, generation of noise in the image signal can be prevented. Such a light guide wall bottom film 150 can be made of, for example, SiO2.

[0084] [Method for manufacturing imaging element]

[0085] Figures 3 to 6 is a view that shows an example of a method for manufacturing an imaging element according to the first embodiment of the present disclosure. Figures 3 to 6 is a view that shows an example of a manufacturing process of the imaging element 1. First, a well region, an n-type semiconductor region 111, or the like is formed on the semiconductor substrate 110 to form a wiring region 120. Next, the semiconductor substrate 110 is inverted upside down to form a groove 131 in a region where the separation portion 130 is disposed. This can be achieved by dry etching Figure 3 A) in FIG. 1.

[0086] Next, the interlayer film 132 is disposed on the back surface side of the semiconductor substrate 110. At this time, a film of a material of the interlayer film 132 is also disposed inside the groove 131. This can be performed, for example, by forming a SiO2 film using a chemical vapor deposition method (CVD). In this way, the separation portion 130 can be formed. As described above, when the separation portion 130 and the interlayer film 132 are made of the same material, they can be formed at the same time.

[0087] Next, a resist 301 is disposed on the surface of the interlayer film 132. In this resist 301, an opening portion 302 is formed in a region where the light guide wall 160 is disposed Figure 3 C) in FIG. 1.

[0088] Next, etching is performed using the resist 301 as a mask to form a recess 169 in the interlayer film 132. This can be performed by dry etching, for example. Then, the resist 301 is peeled off (H in FIG. 10). Figure 4 This process corresponds to the recess formation process.

[0089] Next, a material film 303 of the light guide wall bottom film 150 is disposed on the surface of the interlayer film 132. This can be achieved by forming a SiN film using CVD, for example (E in FIG. 10). Figure 4

[0090] Next, a material film 304 of the light guide wall 160 is disposed on the surface of the material film 303. This can be performed by forming a SiO2 film using CVD, for example (F in FIG. 10). Figure 4

[0091] Next, a resist 305 is disposed on the surface of the material film 304. The resist 305 has an opening portion 306 formed in a region other than the region where the light guide wall 160 is disposed (G in FIG. 10). Figure 5

[0092] Next, etching is performed on the material film 304 using the resist 305 as a mask. This can be performed by dry etching. At this etching, the material film 303 functions as an etching stopper by performing etching under conditions where the selectivity of the material film 303 is higher than that of the material film 304. By this etching, the material film 304 in the opening portion 306 of the resist 305 is removed (H in FIG. 10). This process corresponds to the light guide wall arrangement process. Figure 5

[0093] Next, the material film 303 of the light guide wall bottom film 150 in a region other than the bottom of the light guide wall 160 is removed. This can be performed by dry etching or wet etching using phosphoric acid. At this etching, the material film 303 in the region of the opening portion 306 is etched and removed by performing etching under conditions where the selectivity of the light guide wall 160 is higher than that of the material film 303. As a result, the light guide wall bottom film 150 is formed. Then, the resist 305 is peeled off (I in FIG. 10). Figure 5

[0094] Next, the color filter 140 is disposed in the opening portion 306. This is performed for each type of color filter 140 (J in FIG. 10). Figure 6

[0095] Next, the on-chip lens 170 is disposed on the surface of the color filter 140. This can be performed by a known method (K in FIG. 10). By the above processes, the imaging element 1 can be manufactured. Figure 6 ​​​​​​​

[0096] [Another manufacturing method of an imaging device]

[0097] Figure 7 and Figure 8 is a view showing another example of a manufacturing method of an imaging device according to the first embodiment of the present disclosure. Figure 7 and Figure 8 is a view showing an example of a manufacturing process of an imaging device 1 similar to Figures 3 to 6 The manufacturing process is different from that of the imaging device 1 of Figures 3 to 6 in that the light guide wall 160 is formed after the color filter 140 is disposed. Figure 7 and Figure 8 The manufacturing process shown in Figure 4 is a process after the process E in

[0098] The resist 307 is disposed on the surface of the material film 303 of the light guide wall bottom film 150. The resist 307 is a resist having a shape covering the recess 169 of the material film 303 of the light guide wall bottom film 150, and has an opening portion 308 (F in Figure 7 ) formed in a region other than the region in which the light guide wall 160 is disposed.

[0099] Next, the material film 303 of the light guide wall bottom film 150 is etched with the resist 307 as a mask. This can be performed by dry etching or wet etching. Then, the resist 307 is peeled off. In this way, the light guide wall bottom film 150 (G in Figure 7 ) can be formed.

[0100] Next, the color filter 140 is disposed on the surface of the interlayer film 132. At this time, the color filter 140 is disposed to cover the shape of the light guide wall bottom film 150 (H in Figure 7 ).

[0101] Next, the resist 309 is disposed on the surface of the color filter 140. In this resist 309, an opening portion 310 (I in Figure 8 ) is formed in the region in which the light guide wall 160 is disposed.

[0102] Next, the color filter 140 is etched using the resist 309 as a mask. This etching can be performed by dry etching. At this etching, the light guide wall bottom film 150 can be used as an etching stopper. Specifically, by performing etching under a condition in which the selectivity of the light guide wall bottom film 150 is higher than that of the color filter 140, etching of the color filter 140 can be stopped on the surface of the light guide wall bottom film 150. As a result, the groove 168 (J in Figure 8 ) can be formed. After that, the resist 309 is peeled off.

[0103] Next, the light guide wall 160 is formed by embedding a material of the light guide wall 160 in the groove 168. For example, this can be performed by arranging a SiO2 film as a material of the light guide wall 160 on a surface of the color filter 140 and the groove 168 and removing the SiO2 in a region other than inside the groove 168 by CVD or the like. Specifically, this can be performed by polishing the SiO2 arranged on the surface of the color filter 140 by chemical mechanical polishing (CMP). In this way, the light guide wall 160 can be formed. Figure 8 After that, the imaging element 1 can be manufactured by arranging the on-chip lens 170.

[0104] As described above, in the imaging element 1 of the first embodiment of the present disclosure, the light guide wall 160 extending from the light-receiving end of the color filter 140 to the vicinity of the bottom of the interlayer film 132 is arranged at the boundary of the pixel 100. Therefore, the incident light of the pixel 100 can be guided to the photoelectric conversion unit 101. Therefore, the sensitivity of the pixel 100 can be improved.

[0105] <2. Second Embodiment>

[0106] In the imaging element 1 of the above-described first embodiment, the light guide wall bottom film 150 having a uniform film thickness arranged at the bottom and side surface of the recess 169 of the interlayer film 132 is arranged. On the other hand, the imaging element 1 of the second embodiment of the present disclosure is different from the imaging element of the first embodiment in that the light guide wall bottom film 150 having a different shape is arranged.

[0107] [Configuration of Light Guide Wall and Light Guide Wall Bottom Film]

[0108] Figure 9 is a view showing a configuration example of the light guide wall and the light guide wall bottom film according to the second embodiment of the present disclosure. Figure 9 is a cross-sectional view showing a configuration example of the light guide wall 160 and the light guide wall bottom film 150, and is a simplified view of the light guide wall 160 and the light guide wall bottom film 150.

[0109] A in the drawing is a view showing an example of the light guide wall bottom film 150 in which the bottom surface is thicker than the side surface. By reducing the film thickness of the side surface, absorption of the incident light on the side surface of the light guide wall bottom film 150 can be suppressed. The incident light reflected by the light guide wall 160 in a portion adjacent to the side surface of the light guide wall bottom film 150 can be increased, and reduction in the light guide efficiency of the light guide wall 160 can be reduced. When the light guide wall bottom film 150 formed of a member having a relatively high refractive index such as SiN is employed, it is preferable to employ the shape of the light guide wall bottom film 150 shown in A in the drawing.

[0110] Further, by increasing the film thickness of the bottom surface of the light guide wall bottom film 150, the barrier effect against contaminants can be improved, and diffusion of contaminants into the semiconductor substrate 110 can be further suppressed. Further, by increasing the film thickness of the bottom surface of the light guide wall bottom film 150, the adhesion strength can be improved, and the mechanical strength of the light guide wall 160 can be improved.

[0111] B in the drawing is a drawing showing an example of the light guide wall bottom film 150 having a shape in which the film thickness of the bottom surface is increased and the side surface portion is removed. Absorption of incident light on the side surface of the light guide wall bottom film 150 can be further suppressed, and reduction in the light guide efficiency of the light guide wall 160 can be further reduced.

[0112] Such a light guide wall bottom film 150 having different film thicknesses on the bottom surface and the side surface can be formed by adjusting the step coverage when forming the material film 303 of the light guide wall bottom film 150 by CVD or the like.

[0113] [Other configurations of light guide wall and light guide wall bottom film]

[0114] Figures 10 to 12 is a drawing showing other configuration examples of the light guide wall and the light guide wall bottom film according to the second embodiment of the present disclosure. Like Figure 9 similarly, Figures 10 to 12 is a cross-sectional view showing a configuration example of the light guide wall 160 and the light guide wall bottom film 150, and is a simplified view of the light guide wall 160 and the light guide wall bottom film 150.

[0115] Figure 10 A in the drawing is a drawing showing an example of the light guide wall bottom film 150 having a tapered bottom surface and the light guide wall 160 adjacent to the light guide wall bottom film 150. Like Figure 2 the light guide wall bottom film 150 and the light guide wall 160 described with reference to

[0116] Figure 10 B in the drawing is a drawing showing an example of the light guide wall bottom film 150 having a U-shaped bottom surface and the light guide wall 160 adjacent to the light guide wall bottom film 150. Like Figure 10 the light guide wall bottom film 150 and the light guide wall 160 of A in

[0117] Figure 11A in FIG. 1A is a view showing an example of the light guide wall bottom film having multiple layers. The light guide wall bottom films 150 and 151 are arranged in the light guide wall 160 in A in FIG. 1A. Figure 11 The light guide wall bottom film 151 is a light guide wall bottom film having a different function and effect from the light guide wall bottom film 150. For example, a film having an etching stopper function can be used for the light guide wall bottom film 151, and a film having a function of blocking incident light can be used for the light guide wall bottom film 150. Specifically, the light guide wall bottom film 151 can be made of SiN, and the light guide wall bottom film 150 can be made of W. Further, for example, a film for improving adhesion strength can be used for the light guide wall bottom film 150. In this case, the light guide wall bottom film 150 can be made of SiO2. Further, for example, a film for preventing the movement of contaminants can be used for the light guide wall bottom film 150. Likewise, in this case, the light guide wall bottom film 150 can be made of SiO2.

[0118] Figure 11 The configuration of the light guide wall bottom film in A is not limited to this example. For example, a light guide wall bottom film in which three or more layers are laminated can also be used.

[0119] Figure 11 B in FIG. 1B shows an example in which the light guide wall bottom film is omitted. The light guide wall 160 in B is arranged adjacent to the recessed portion 169 of the interlayer film 132.

[0120] Figure 12 A in FIG. 1A is a view showing an example of the light guide wall bottom film having a shape in which the width of the portion arranged in the region of the interlayer film 132 is reduced. Figure 12 The light guide wall 160 in A can be formed by arranging a recessed portion 169 having a width narrower than the width of the light guide wall 160 in the interlayer film 132.

[0121] Figure 12 B in FIG. 1B is a view showing a light guide wall bottom film 150 having a shape that protrudes in the outer side region of the light guide wall 160. The light shielding ability of the light guide wall bottom film 150 can be improved.

[0122] Figure 12 C in FIG. 1C shows an example in which the light guide wall 160 has a width narrower than the width of the recessed portion 169 of the interlayer film 132. This is an example in which the recessed portion 169 is provided with a dimensional allowance in consideration of variations in forming the light guide wall 160.

[0123] The configuration of the imaging device 1 other than the above-described configuration is the same as the configuration of the imaging device 1 described in the first embodiment of the present disclosure, and thus the description thereof will be omitted.

[0124] As described above, in the imaging element 1 of the second embodiment of the present disclosure, the light guide wall 160 and the light guide wall bottom film 150 having shapes different from those of the first embodiment are arranged, thereby being able to guide incident light.

[0125] <3. Third Embodiment>

[0126] In the imaging element 1 of the above-described first embodiment, the separation portion 130 is formed in the semiconductor substrate 110. On the other hand, the imaging element 1 of the third embodiment of the present disclosure is different from the first embodiment in that the separation portion 130 is omitted.

[0127] [Pixel Configuration]

[0128] Figure 13 is a view showing a configuration example of a pixel according to the third embodiment of the present disclosure. Figure 13 is a schematic cross-sectional view showing a configuration example of a pixel 100 similar to the pixel 100. Figure 2 The pixel is different from the pixel 100 described above in that the separation portion 130 is omitted. Figure 2

[0129] The semiconductor substrate 110 in the view has a well region arranged at a boundary of the pixel 100, and each pixel 100 is separated from an adjacent pixel 100. By arranging a well region having a high impurity concentration as a well region at the boundary of the pixel 100, the separation ability of the pixel 100 can be improved. Since the light guide wall 160 is arranged in a region of the color filter 140 and the interlayer film 132, incident light is guided in the same manner as in the imaging element 1 of the first embodiment. Figure 2

[0130] The configuration of the imaging element 1 other than the above-described configuration is the same as the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and thus the description thereof will be omitted.

[0131] As described above, in the imaging element 1 of the third embodiment of the present disclosure, the configuration of the pixel 100 can be simplified by omitting the separation portion 130 of the semiconductor substrate 110.

[0132] <4. Fourth Embodiment>

[0133] The imaging element 1 of the above-described first embodiment uses the light guide wall 160 made of resin or the like. On the other hand, the imaging element 1 of the fourth embodiment of the present disclosure is different from the imaging element 1 of the first embodiment in that a light guide wall formed of a gap is used.

[0134] [Pixel Configuration]

[0135] Figure 14 is a view showing a configuration example of a pixel according to the fourth embodiment of the present disclosure. The view is a view showing a configuration example of a pixel 100 similar to the pixel 100.​​Figure 2 A schematic cross-sectional view of a configuration example of a pixel 100 similar to the pixel 100 shown in FIG. 1. This pixel is different from the pixel 100 shown in FIG. 1 in that a light guide wall 164 is arranged instead of the light guide wall 160, and a sealing film 172 is also arranged. Figure 2

[0136] The light guide wall 164 in the drawing is formed by a gap. This gap can be formed by, for example, enclosing a gas in a recess 168 formed in the color filter 140 and a recessed portion 169 of the interlayer film 132. In addition, the gap can be evacuated. Since such a gap has a low refractive index, the light guide efficiency can be improved by arranging the light guide wall 164. Such a gap can be formed by forming the recess 168 at the boundary of the pixel 100 on which the color filter 140 and the on-chip lens 170 are formed and sealing the upper portion of the recess 168.

[0137] The sealing film 172 is arranged on the upper surface of the light guide wall 164 to seal the light guide wall 164 formed by the gap. The sealing film 172 is arranged on the front surface and the side surface of the on-chip lens 170 to seal the recess 168 described above. The sealing film 172 can be made of, for example, resin or SiO2.

[0138] [Method for manufacturing imaging element]

[0139] Figure 15 and Figure 16 are drawings showing an example of a method for manufacturing an imaging element according to the fourth embodiment of the present disclosure. Figure 15 and Figure 16 are drawings showing an example of the manufacturing process of the imaging element 1, and are Figure 6 processes after process K in

[0140] First, a resist 311 is arranged on the surface of the on-chip lens 170. The resist 311 has an opening portion 312 formed in the region where the light guide wall 164 is arranged (L in Figure 15 ).

[0141] Next, using the resist 311 as a mask, the on-chip lens 170 and the light guide wall 160 are etched. This can be performed by dry etching. As a result, the recess 168 is formed in the region where the light guide wall 160 and the end portion of the on-chip lens 170 are arranged (M in Figure 15 ).

[0142] Next, the sealing film 172 is arranged to seal the recess 168. This can be performed by applying resin as the material of the sealing film 172. Furthermore, when a SiO2 film is employed as the sealing film 172, it can be formed by CVD (N in Figure 16 ).

[0143] ​Through the above process, a light guide wall 164 formed by gaps can be manufactured. As described above, in the process of... Figure 15 In the process shown in M, the light guide wall 160 is removed by etching. Therefore, it is preferable that the light guide wall 160 is formed of a component that can be easily removed by dry etching, such as acrylic resin.

[0144] [Another manufacturing method for imaging elements]

[0145] Figure 17 This is a diagram illustrating an example of a method for manufacturing an imaging element according to a fourth embodiment of the present disclosure. Figure 17 This is a diagram illustrating an example of the manufacturing process of imaging element 1, and is... Figure 7 The process after process H in the middle.

[0146] First, an on-plate lens 170 is formed on the surface of the color filter 140. Next, the aforementioned photoresist 311 is formed on the surface of the on-plate lens 170. Figure 17 (L in the middle). Next, with Figure 15 The etching is performed in the same manner as process M to form the groove 168, and in accordance with... Figure 16 The sealing film 172 is arranged in the same manner as in process N. Alternatively, a light guide wall 164 formed by gaps can be formed through the above process.

[0147] The imaging element 1, apart from the above-described configuration, has the same configuration as the imaging element 1 described in the first embodiment of this disclosure, and therefore its description will be omitted.

[0148] As described above, in the imaging element 1 of the fourth embodiment of this disclosure, the sensitivity of the pixel 100 can be further improved by arranging the light guide wall 164 formed by the gap.

[0149] <5. Fifth Implementation Plan>

[0150] In the imaging element 1 of the first embodiment described above, the light guide wall 160 is arranged adjacent to the color filter 140. On the other hand, the imaging element 1 of the fifth embodiment of this disclosure differs from the imaging element of the first embodiment in that a protective film is arranged between the light guide wall 160 and the color filter 140.

[0151] [Pixel Composition]

[0152] Figure 18 This is a diagram illustrating an example of pixel configuration according to a fifth embodiment of the present disclosure. The diagram illustrates... Figure 2 A schematic cross-sectional view of a similar pixel 100. This pixel is related to... Figure 2 The difference in the pixel 100 described herein is that a protective film 165 is further arranged thereon.

[0153] A protective film 165 is arranged between the light guide wall 160 and the color filter 140 to protect the light guide wall 160. The protective film 165 can be made of, for example, a SiO2 film. The protective film 165 in the figure is further arranged between the color filter 140 and the interlayer film 132. By arranging the protective film 165, the light guide wall 160 can be prevented from being damaged in a manufacturing process of the imaging element 1 or the like. The protective film 165 can be formed, for example, by laminating a SiO2 film on the surface of the light guide wall 160 and the interlayer film 132 after process I. Figure 5

[0154] The configuration of the imaging element 1 other than the above-described configuration is the same as the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and thus the description thereof will be omitted.

[0155] As described above, the imaging element 1 of the fifth embodiment of the present disclosure can protect the light guide wall 160 by arranging the protective film 165. The strength of the pixel 100 can be improved in a manufacturing process of the imaging element 1.

[0156] <6. Application example of camera>

[0157] The technology according to the present disclosure (the present technology) can be applied to various products. For example, the present technology can be implemented as an imaging element mounted in an imaging device such as a camera.

[0158] Figure 19 is a block diagram showing a schematic configuration example of a camera that is an example of an imaging device to which the present technology can be applied. The camera 1000 in the figure includes a lens 1001, an imaging element 1002, an imaging control unit 1003, a lens driving unit 1004, an image processing unit 1005, an operation input unit 1006, a frame memory 1007, a display unit 1008, and a recording unit 1009.

[0159] The lens 1001 is an imaging lens of the camera 1000. The lens 1001 converges light from a subject and causes the converged light to be incident on the imaging element 1002 described later to image the subject.

[0160] The imaging element 1002 is a semiconductor element that images light from a subject converged by the lens 1001. The imaging element 1002 generates an analog image signal in response to the irradiation light, converts the analog image signal into a digital image signal, and outputs the digital image signal.

[0161] ​The imaging control unit 1003 controls imaging in the imaging element 1002. The imaging control unit 1003 controls the imaging element 1002 by generating and outputting a control signal to the imaging element 1002. In addition, the imaging control unit 1003 can perform auto focus in the camera 1000 based on an image signal output from the imaging element 1002. Here, the auto focus is a system that detects a focus position of the lens 1001 and automatically adjusts the focus position. As the auto focus, a method of detecting a focus position by detecting an image plane phase difference according to a phase difference pixel arranged in the imaging element 1002 (image plane phase difference auto focus) can be used. In addition, a method of detecting a position at which a contrast of an image is the largest as the focus position (contrast auto focus) can also be applied. The imaging control unit 1003 adjusts the position of the lens 1001 by the lens drive unit 1004 based on the detected focus position, and performs auto focus. Meanwhile, the imaging control unit 1003 can be configured as, for example, a digital signal processor (DSP) provided with firmware.

[0162] The lens drive unit 1004 drives the lens 1001 based on the control of the imaging control unit 1003. The lens drive unit 1004 can drive the lens 1001 by changing the position of the lens 1001 using a motor embedded therein.

[0163] The image processing unit 1005 processes an image signal generated by the imaging element 1002. For example, the processing corresponds to demosaicing for generating an image signal of an omitted color among image signals corresponding to red, green, and blue of each pixel, noise removal for removing noise in the image signal, image signal encoding, and the like. The image processing unit 1005 can be configured as, for example, a microcomputer with firmware.

[0164] The operation input unit 1006 receives an operation input by a user of the camera 1000. For example, a button or a touch panel can be used as the operation input unit 1006. The operation input received by the operation input unit 1006 is sent to the imaging control unit 1003 and the image processing unit 1005. Thereafter, for example, a process responsive to the operation input, a process of imaging a subject, and the like are started.

[0165] The frame memory 1007 is a memory that stores a frame that is an image signal corresponding to one screen. The frame memory 1007 is controlled by the image processing unit 1005 and holds a frame in the course of image processing.

[0166] The display unit 1008 displays an image processed by the image processing unit 1005. For example, a liquid crystal panel can be used as the display unit 1008.

[0167] The recording unit 1009 records the image processed by the image processing unit 1005. For example, a memory card or a hard disk can be used as the recording unit 1009.

[0168] The camera to which the present disclosure can be applied has been described above. The present technology can be applied to the imaging element 1002 in the above-described assembly. Specifically, Figure 1 The imaging element 1 described in the above embodiment can be applied to the imaging element 1002. By applying the imaging element 1 to the imaging element 1002, the sensitivity of the camera 1000 can be improved. Meanwhile, the image processing unit 1005 is an example of the processing circuit described in the claims. The camera 1000 is an example of the imaging apparatus described in the claims.

[0169] The configuration of the pixel 100 of the second embodiment can be combined with other embodiments. Specifically, Figures 9 to 12 The shape of the light guide wall 160 and the light guide wall bottom film 150 in Figure 13 and Figure 14 can be applied to the light guide wall 160 and the light guide wall bottom film 150.

[0170] The configuration of the pixel 100 of the third embodiment can be combined with other embodiments. Specifically, in the pixel 100 of Figures 9 to 12 and Figure 14 , the separation portion 130 of the semiconductor substrate 110 can be omitted.

[0171] The configuration of the pixel 100 of the fourth embodiment can be combined with other embodiments. Specifically, Figure 14 The light guide wall 164 and the sealing film 172 of Figures 9 to 13 can be applied to the pixel 100.

[0172] Finally, the description of each of the above-described embodiments is an example of the present disclosure, and the present disclosure is not limited to the above-described embodiments. Therefore, it goes without saying that, in addition to the above-described embodiments, various modifications can be made in accordance with design and the like without departing from the technical spirit according to the present disclosure.

[0173] In addition, the effects described in this specification are merely illustrative or exemplary

[0174] In addition, the drawings in the above-described embodiments are schematic, and the size ratio and the like of each portion do not necessarily conform to the actual one. In addition, it goes without saying that the drawings include portions whose size relationship and proportions differ between the drawings.

[0175] Furthermore, the present technology can also have the following configuration.

[0176] (1) An imaging element comprising:

[0177] A pixel, each of the pixels including: a photoelectric conversion unit arranged in a semiconductor substrate to perform photoelectric conversion on incident light, an on-chip lens that converges the incident light on the photoelectric conversion unit, a color filter that transmits incident light having a predetermined wavelength among the converged incident light, and an interlayer film arranged between the semiconductor substrate and the color filter; and

[0178] A light guide wall arranged at a boundary of the pixel and formed in a shape surrounding the color filter, the light guide wall having an end portion arranged in a recess around the pixel to guide the incident light, the recess being formed in the interlayer film at the boundary of the pixel.

[0179] (2) The imaging element according to (1), wherein the light guide wall is formed of a member having a refractive index different from that of the color filter.

[0180] (3) The imaging element according to (2), wherein the light guide wall is formed of a member having a refractive index lower than that of the color filter.

[0181] (4) The imaging element according to (3), wherein the light guide wall is made of an oxide.

[0182] (5) The imaging element according to (3), wherein the light guide wall is made of a resin.

[0183] (6) The imaging element according to (3), wherein the light guide wall is formed of a void.

[0184] (7) The imaging element according to any one of (1) to (6), further comprising: a separation portion arranged in the semiconductor substrate at the boundary of the pixel to separate the photoelectric conversion unit.

[0185] (8) The imaging element according to any one of (1) to (7), further comprising: a light guide wall bottom film that is a film arranged at a bottom of the recess and adjacent to the light guide wall.

[0186] (9) The imaging element according to (8), wherein the light guide wall bottom film is further arranged on a side surface of the recess.

[0187] (10) The imaging element according to (8), wherein the light guide wall bottom film is a film that stops etching progress when the light guide wall is formed by etching.

[0188] (11) The imaging element according to (8), wherein the light guide wall bottom film is a film that blocks the incident light.

[0189] (12) The imaging element according to (8), wherein the light guide wall bottom portion film is a film that brings the light guide wall into close contact with the interlayer film.

[0190] (13) The imaging element according to (8), wherein the light guide wall bottom portion film is a film that prevents contaminants from moving to the semiconductor substrate.

[0191] (14) The imaging element according to (8), wherein the light guide wall bottom portion film is made of metal.

[0192] (15) The imaging element according to (8), wherein the light guide wall bottom portion film is made of silicon nitride.

[0193] (16) The imaging element according to (8), wherein the light guide wall bottom portion film is made of an oxide.

[0194] (17) The imaging element according to any one of (1) to (16), further comprising: a protective film arranged between the color filter and the light guide wall.

[0195] (18) An imaging device comprising:

[0196] pixels each including a photoelectric conversion unit arranged in a semiconductor substrate to perform photoelectric conversion on incident light, an on-chip lens that concentrates the incident light on the photoelectric conversion unit, a color filter that transmits incident light having a predetermined wavelength among the concentrated incident light, and an interlayer film arranged between the semiconductor substrate and the color filter;

[0197] a light guide wall arranged at a boundary of the pixels and formed in a shape surrounding the color filter, the light guide wall having an end portion arranged in a recess surrounding the pixels to guide the incident light, the recess being formed in the interlayer film at the boundary of the pixels; and

[0198] processing circuitry that processes an image signal generated based on the photoelectric conversion.

[0199] [LIST OF REFERENCE NUMERALS]

[0200] 1 imaging element

[0201] 10 pixel array unit

[0202] 30 column signal processing unit

[0203] 100 pixel

[0204] 101 photoelectric conversion unit

[0205] 110 semiconductor substrate

[0206] 130 separation portion

[0207] 131, 168 recess

[0208] 132 interlayer film

[0209] 140 color filter

[0210] 150 light guide wall bottom film

[0211] 151 light guide wall bottom film

[0212] 160, 164 light guide wall

[0213] 165 protective film

[0214] 169 recess

[0215] 170 on-chip lens

[0216] 172 sealing film

[0217] 1002 imaging element

[0218] 1005 image processing unit

Claims

1. An imaging element comprising: a plurality of pixels, wherein the plurality of pixels includes: a semiconductor substrate, wherein the semiconductor substrate has a front side and a back side; a wiring layer arranged on the front side of the semiconductor substrate; an interlayer film arranged on the back side of the semiconductor substrate and having a recess at a boundary between pixels; a first color filter and a second color filter arranged laterally over a light incident side of the interlayer film in a cross-sectional view; a film arranged at least on the recess; and a region arranged between the first color filter and the second color filter, wherein the film is arranged between the region and the recess.

2. The imaging element according to claim 1, wherein The region is formed of a member having a refractive index different from that of the first color filter and the second color filter.

3. The imaging element according to claim 2, wherein The region is formed of a member having a refractive index lower than that of the first color filter and the second color filter.

4. The imaging element according to claim 3, wherein The region is made of an oxide.

5. The imaging element according to claim 3, wherein The region is made of a resin.

6. The imaging element according to claim 3, wherein The region is a void.

7. The imaging element according to claim 1, further comprising: a separation portion arranged in the semiconductor substrate at a boundary of the pixels to separate photoelectric conversion units of the pixels.

8. The imaging element according to claim 1, wherein The film is an etching stop film.

9. The imaging element according to claim 1, wherein The film is a film that blocks incident light.

10. The imaging element according to claim 1, wherein The film is a film that brings the region into close contact with the interlayer film.

11. The imaging element according to claim 1, wherein The film is a film that prevents contaminants from moving to the semiconductor substrate.

12. The imaging element according to claim 1, wherein The film is made of a metal.

13. The imaging element according to claim 1, wherein The film is made of silicon nitride.

14. The imaging element according to claim 1, wherein The film is made of an oxide.

15. The imaging element according to any one of claims 1 to 6, further comprising: a protective film arranged between the first color filter and the second color filter and the region. 16.An imaging device comprising: a plurality of pixels, wherein the plurality of pixels includes: a semiconductor substrate, wherein the semiconductor substrate has a front side and a back side; a wiring layer arranged on the front side of the semiconductor substrate; an interlayer film arranged on the back side of the semiconductor substrate and having a recess at a boundary between pixels; a first color filter and a second color filter arranged laterally over a light incident side of the interlayer film in a cross-sectional view; a film arranged at least on the recess; and a region arranged between the first color filter and the second color filter, wherein the film is arranged between the region and the recess; and a processing circuit that processes an image signal generated by the pixels.

Images