Image sensor and image pickup device

Abstract

To reduce reflected light of a backside-illumination type photoelectric conversion element.SOLUTION: An imaging element includes an on-chip lens, a photoelectric conversion unit, and an absorption film. The on-chip lens included in this imaging element focuses incident light. The photoelectric conversion unit included in this imaging element is configured on a semiconductor substrate and performs photoelectric conversion on the focused incident light. The absorption film included in this imaging element is arranged to be adjacent to the semiconductor substrate, and has an opening portion having substantially the same size as the focusing size of the focused incident light to absorb the reflected light of the incident light.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an imaging element and an imaging apparatus, and more particularly to an imaging element in which incident light is irradiated from a rear surface of a semiconductor substrate, and an imaging apparatus using the imaging element. [Background technology]

[0002] Conventionally, imaging elements have been used in which incident light is irradiated onto the back side of a semiconductor substrate on which a photoelectric conversion unit such as a photodiode that photoelectrically converts incident light is formed. Since the incident light is irradiated onto the photoelectric conversion unit without passing through a wiring region formed on the front surface of the semiconductor substrate, it is possible to improve sensitivity.

[0003] As such an imaging element, for example, an imaging element in which a photodiode and the like are formed in the silicon layer of an SOI (Silicon on Insulator) substrate configured by sequentially stacking an intermediate layer and a silicon layer on a silicon substrate is used (see, for example, Patent Document 1). In this imaging element, a wiring section (wiring area) is disposed on the surface of the silicon layer in which a light receiving sensor section such as a photodiode is formed. After a support substrate is bonded to this wiring area, the silicon substrate and the intermediate layer are removed. Thin film silicon having a thickness of 10 μm or less can be used for the silicon layer. Since a process of thinning the semiconductor substrate by grinding or the like is not required, a silicon layer with a stable thickness can be manufactured with a good yield. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-335905 A Summary of the Invention [Problem to be solved by the invention]

[0005] The above-mentioned conventional technology has a problem in that there is a lot of reflected light from the image sensor. Because a thin silicon layer is used as the semiconductor substrate on which the photodiodes and the like are formed, incident light that is not absorbed by the semiconductor substrate reaches the wiring region and is reflected, resulting in a large amount of reflected light. If this reflected light is again incident on the image sensor, it will cause flare, etc., resulting in a deterioration in image quality.

[0006] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to reduce reflected light in a back-illuminated imaging element. [Means for solving the problem]

[0007] The present disclosure has been made to solve the above-mentioned problems, and a first aspect thereof is an imaging element including an on-chip lens that collects incident light, a photoelectric conversion unit that is configured on a semiconductor substrate and performs photoelectric conversion of the collected incident light, and an absorbing film that is disposed adjacent to the semiconductor substrate, has an opening that is approximately the same size as the collected size of the collected incident light, and absorbs reflected light of the incident light.

[0008] In addition, in the first aspect, a reflective film may be further provided, which is disposed between the semiconductor substrate and the absorbing film and reflects the reflected light.

[0009] In this first aspect, the reflective film may have an opening having a different size from the opening of the absorbing film.

[0010] In the first aspect, the absorbing film may be configured in a shape in which the opening area on the semiconductor substrate side is smaller than the opening area on the on-chip lens side of the opening.

[0011] In the first aspect, the absorbing film may have the opening configured in a tapered shape.

[0012] In the first aspect, the absorbing film may be composed of a plurality of layers having different absorption coefficients.

[0013] In the first aspect, the absorbing film may be configured by dispersing an absorbing member that absorbs the incident light.

[0014] In the first aspect, the absorbing film may be configured to have a thickness substantially the same as the diameter of the opening.

[0015] In addition, in the first aspect, a second reflective film may be further provided, which is disposed on a side of the semiconductor substrate different from the side adjacent to the absorbing film and reflects the incident light transmitted through the semiconductor substrate.

[0016] In addition, in the first aspect, a scattering section that scatters the reflected light may be further provided.

[0017] In the first aspect, the scattering portion may be configured by an uneven portion formed on the surface of the semiconductor substrate adjacent to the opening of the absorbing film.

[0018] In addition, in this first aspect, the scattering portion may be disposed on a side of the semiconductor substrate different from the side adjacent to the absorbing film, and may reflect and scatter the incident light transmitted through the semiconductor substrate.

[0019] In the first aspect, the liquid crystal display device may further include a plurality of pixels each of which is configured with the on-chip lens, the photoelectric conversion portion, and the absorbing film.

[0020] In the first aspect, the pixel may further include a color filter that transmits incident light of a predetermined wavelength out of the incident light.

[0021] In the first aspect, the color filter may transmit the incident light having a long wavelength.

[0022] In the first aspect, the color filter may transmit red light.

[0023] In the first aspect, the color filter may transmit infrared light.

[0024] In the first aspect, the absorbing film may be arranged such that the position of the opening is shifted depending on the angle of incidence of the light incident on the pixel.

[0025] In the first aspect, the absorbing film may be configured so that the opening is extended in accordance with an incident angle of the light incident on the pixel.

[0026] Also, a second aspect of the present disclosure is an imaging device including an on-chip lens that collects incident light, a photoelectric conversion unit that is configured on a semiconductor substrate and performs photoelectric conversion of the collected incident light, an absorption film that is arranged adjacent to the semiconductor substrate and has an opening that is approximately the same size as the collected size of the collected incident light and absorbs reflected light of the incident light, and a processing circuit that processes an image signal generated based on the photoelectric conversion.

[0027] By adopting the above-described embodiment, the effect is achieved that the incident light to be collected is transmitted while the reflected light is absorbed. [Brief description of the drawings]

[0028] [Figure 1] FIG. 1 is a diagram illustrating an example of a configuration of an imaging element according to an embodiment of the present disclosure. [Diagram 2] 1 is a cross-sectional view showing a configuration example of a pixel according to a first embodiment of the present disclosure. [Diagram 3] FIG. 2 is a diagram illustrating an example of a pixel configuration according to a first embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating an example of absorption of reflected light according to the first embodiment of the present disclosure. [Diagram 5] FIG. 4 is a cross-sectional view showing another configuration example of the pixel according to the first embodiment of the present disclosure. [Figure 6] FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a second embodiment of the present disclosure. [Figure 7]FIG. 11 is a cross-sectional view showing another configuration example of a pixel according to the second embodiment of the present disclosure. [Figure 8] FIG. 11 is a cross-sectional view showing a configuration example of a pixel according to a third embodiment of the present disclosure. [Figure 9] FIG. 13 is a diagram illustrating an example of absorption of reflected light according to a third embodiment of the present disclosure. [Figure 10] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. [Figure 11] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure. [Figure 12] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. [Figure 13] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a seventh embodiment of the present disclosure. [Figure 14] FIG. 13 is a diagram illustrating an example of a pixel configuration according to an eighth embodiment of the present disclosure. [Figure 15] FIG. 13 is a cross-sectional view showing a configuration example of a pixel according to a ninth embodiment of the present disclosure. [Figure 16] FIG. 13 is a diagram illustrating an example of a pixel configuration according to a ninth embodiment of the present disclosure. [Figure 17] FIG. 23 is a cross-sectional view showing a configuration example of a pixel according to a tenth embodiment of the present disclosure. [Figure 18] 1 is a block diagram showing a schematic configuration example of a camera that is an example of an imaging device to which the present disclosure can be applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Next, a mode for carrying out the present disclosure (hereinafter, referred to as an embodiment) will be described with reference to the drawings. In the following drawings, the same or similar parts are given the same or similar reference numerals. The embodiment will be described in the following order. 1. First embodiment 2. Second embodiment 3. Third embodiment 4. Fourth embodiment 5. Fifth embodiment 6. Sixth embodiment 7. Seventh embodiment 8. Eighth embodiment 9. Ninth embodiment 10. Tenth embodiment 11. Camera application example

[0030] <1. First embodiment> [Image sensor configuration] 1 is a diagram showing an example of the configuration of an image sensor according to an embodiment of the present disclosure. The image sensor 1 in the figure includes a pixel array section 10, a vertical drive section 20, a column signal processing section 30, and a control section 40.

[0031] The pixel array section 10 is configured by arranging pixels 100 in a two-dimensional lattice. Here, the pixel 100 generates an image signal according to irradiated light. The pixel 100 has a photoelectric conversion section that generates an electric charge according to irradiated light. The pixel 100 further has a pixel circuit. The pixel circuit generates an image signal based on the electric charge generated by the photoelectric conversion section. The generation of the image signal is controlled by a control signal generated by a vertical driving section 20 described later. In the pixel array section 10, signal lines 11 and 12 are arranged in an XY matrix. The signal line 11 is a signal line that transmits a control signal for the pixel circuit in the pixel 100, is arranged for each row of the pixel array section 10, and is commonly wired to the pixels 100 arranged in each row. The signal line 12 is a signal line that transmits an image signal generated by the pixel circuit of the pixel 100, is arranged for each column of the pixel array section 10, and is commonly wired to the pixels 100 arranged in each column. These photoelectric conversion sections and pixel circuits are formed on a semiconductor substrate.

[0032] The vertical driving unit 20 generates a control signal for the pixel circuit of the pixel 100. The vertical driving unit 20 transmits the generated control signal to the pixel 100 via a signal line 11 in the figure. The column signal processing unit 30 processes an image signal generated by the pixel 100. The column signal processing unit 30 processes an image signal transmitted from the pixel 100 via a signal line 12 in the figure. The processing in the column signal processing unit 30 corresponds to, for example, analog-to-digital conversion that converts 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 image sensor 1. The control unit 40 controls the entire image sensor 1. The control unit 40 controls the image sensor 1 by generating and outputting a control signal that controls the vertical driving unit 20 and the column signal processing unit 30. The control signal generated by the control unit 40 is transmitted to the vertical driving unit 20 and the column signal processing unit 30 via signal lines 41 and 42, respectively.

[0033] The image sensor 1 in the figure is an example of an image sensor as defined in the claims. The pixel array section 10 in the figure is an example of an image sensor as defined in the claims. The column signal processing section 30 in the figure is an example of a processing circuit as defined in the claims.

[0034] [Pixel configuration] 2 is a cross-sectional view showing a configuration example of a pixel according to the first embodiment of the present disclosure. The figure is a cross-sectional view showing a configuration example of a pixel 100. The pixel 100 in the figure includes a semiconductor substrate 101, a wiring region 110, a reflective film 140, an absorbing film 150, a protective film 160, and an on-chip lens 180.

[0035] The semiconductor substrate 101 is a semiconductor substrate on which the semiconductor regions (diffusion regions) of the elements constituting the photoelectric conversion unit and pixel circuit described above are formed. This semiconductor substrate 101 can be made of silicon (Si). Elements such as the photoelectric conversion unit are disposed in a well region formed in the semiconductor substrate 101. For convenience, the semiconductor substrate 101 in the figure is assumed to constitute a p-type well region. By forming an n-type semiconductor region in this p-type well region, the diffusion region of the elements can be formed. In the semiconductor substrate 101 in the figure, an n-type semiconductor region 102 constituting the photoelectric conversion unit is illustrated as an example of an element. A photodiode formed by a pn junction at the interface between this n-type semiconductor region 102 and the surrounding p-type well region corresponds to the photoelectric conversion unit. When incident light is irradiated onto this n-type semiconductor region 102, photoelectric conversion occurs. Charges generated by this photoelectric conversion are accumulated in the n-type semiconductor region 102. An image signal is generated by a pixel circuit (not shown) based on the accumulated charges.

[0036] In addition, a separation region 130 can be arranged at the boundary of the pixels 100 in the semiconductor substrate 101 in the figure. This separation region 130 optically separates the pixels 100. Specifically, a film that reflects incident light is arranged between the pixels 100 as the separation region 130, thereby preventing the incident light from leaking to the adjacent pixels 100. This makes it possible to prevent crosstalk between the pixels 100. The separation region 130 can be made of a metal such as tungsten (W). A fixed charge film and an insulating film can be arranged between the separation region 130 and the semiconductor substrate 101. The fixed charge film is a film that is arranged at the interface of the semiconductor substrate 101 and pins the surface state of the semiconductor substrate 101. The insulating film is a film that is arranged between the fixed charge film and the separation region 130 and insulates the separation region 130. Such a separation region 130 can be formed by forming a fixed charge film and an insulating film on the surface of a groove formed in the semiconductor substrate 101 and filling it with a metal such as W. By disposing the isolation region 130 having such an insulating film, the pixels 100 can be electrically isolated.

[0037] The wiring region 110 is disposed adjacent to the surface of the semiconductor substrate 101, and is a region in which wiring for transmitting signals is formed. The wiring region 110 in the figure includes a wiring layer 112 and an insulating layer 111. The wiring layer 112 is a conductor for transmitting signals to elements of the semiconductor substrate 101. This wiring layer 112 can be made of a metal such as copper (Cu) or tungsten (W). The insulating layer 111 insulates the wiring layer 112. This insulating layer 111 can be made of, for example, silicon oxide (SiO 2 ) The wiring layer 112 and the insulating layer 111 can be configured in multiple layers. The figure shows an example of wiring configured in three layers. The wiring layers 112 arranged on different layers can be connected to each other by via plugs (not shown).

[0038] The image sensor 1 in the figure corresponds to a back-illuminated image sensor in which incident light is irradiated onto a photoelectric conversion unit from the back side of the semiconductor substrate 101. Incident light from a subject that is incident on the semiconductor substrate 101 via an on-chip lens 180, an absorbing film 150, and a reflecting film 140 (described later) is absorbed by the semiconductor substrate 101 and photoelectrically converted. However, the incident light that is not absorbed by the semiconductor substrate 101 passes through the semiconductor substrate 101 and becomes transmitted light, and enters the wiring region 110. A part of the transmitted light that is incident on the wiring region 110 is reflected by the wiring layer 112 and becomes reflected light, and enters the semiconductor substrate 101 again. The reflected light is again incident on the semiconductor substrate 101 and photoelectrically converted, thereby improving the sensitivity of the pixel 100. However, if the reflected light is transmitted through the semiconductor substrate 101 and irradiated to the outside of the pixel 100, and is reflected by a housing or the like and enters the image sensor 1 again, flare or the like occurs, and image quality is degraded.

[0039] The reflective film 140 is disposed adjacent to the rear surface of the semiconductor substrate 101 to transmit incident light from a subject and reflect reflected light. The reflective film 140 has an opening 149 in the center, and transmits incident light collected by an on-chip lens 180 (described later) through the opening 149. The reflective film 140 also reflects the reflected light again and makes it incident on the semiconductor substrate 101, thereby reducing leakage of the reflected light to the outside of the pixel 100. The reflective film 140 can be made of a metal such as W, similar to the separation region 130. The reflective film 140 can be formed simultaneously with the separation region 130. Specifically, when filling a groove formed in the semiconductor substrate 101 with a metal that is the material of the separation region 130, a material film is also formed on the rear surface of the semiconductor substrate 101. The reflective film 140 can be manufactured by forming an opening 149 in the formed material film. The opening 149 can be configured to be approximately the same size as the size of the incident light collected by the on-chip lens 180.

[0040] The absorbing film 150 is disposed on the back surface of the semiconductor substrate 101 to transmit incident light from a subject and absorb reflected light. The absorbing film 150 has an opening 159 in the center, and transmits incident light collected by the on-chip lens 180 through the opening 159. The absorbing film 150 also absorbs reflected light to reduce leakage of reflected light to the outside of the pixel 100. The absorbing film 150 in the figure is disposed adjacent to the reflective film 140, and absorbs reflected light transmitted through the opening 149 of the reflective film 140. The absorbing film 150 can be formed, for example, by a film in which an absorbing member that absorbs incident light is dispersed. For example, a pigment that absorbs light, such as carbon black or titanium oxide, is used as the absorbing member, and the absorbing film 150 can be formed by a film in which the pigment is dispersed in a resin or the like. Such an absorbing film 150 can be manufactured by forming a resin film in which a pigment is dispersed adjacent to the reflective film 140 and forming an opening 159. The opening 159 can be formed by dry etching or wet etching using a chemical solution. It is also possible to use an absorbing film 150 having a dye-based absorbing member such as an infrared light absorbing agent.

[0041] The protective film 160 is a film that insulates and protects the back surface side of the semiconductor substrate 101. The protective film 160 in the figure is disposed adjacent to the absorbing film 150, and further flattens the back surface side of the semiconductor substrate 101 on which the reflective film 140 and the absorbing film 150 are disposed. This protective film 160 is, for example, SiO 2 It is also possible to adopt a configuration in which a protective film is disposed on the surface of the reflective film 140. Specifically, after the reflective film 140 is formed, a protective film, such as SiO 2 Then, the absorbing film 150 is formed. This allows the protective film 160 to be disposed in the region between the reflective film 140 and the absorbing film 150.

[0042] The on-chip lens 180 is a lens disposed for each pixel 100 and focuses incident light from a subject onto a photoelectric conversion unit of the semiconductor substrate 101. The on-chip lens 180 is configured in a convex lens shape and focuses incident light. The on-chip lens 180 in the figure focuses incident light onto the photoelectric conversion unit via the opening 159 of the absorbing film 150 and the opening 149 of the reflecting film 140 described above. The arrows in the figure show how the on-chip lens 180 focuses light. The on-chip lens 180 can be made of, for example, an organic material such as a resin or an inorganic material such as silicon nitride (SiN).

[0043] As shown in the figure, incident light is condensed by the on-chip lens 180, and a focal point is formed in a region of the semiconductor substrate 101. The light incident on the on-chip lens 180 is gradually narrowed while traveling from the on-chip lens 180 to the semiconductor substrate 101, and the condensed size, which is the irradiation range of the incident light in the horizontal direction, becomes narrow. By configuring the opening 159 of the absorbing film 150 to have a size substantially equal to the condensed size of the incident light, it is possible to reduce leakage of reflected light from the opening 159 while preventing the shading (vignetting) of the incident light condensed by the on-chip lens 180 by the absorbing film 150. By configuring the opening 149 of the reflecting film 140 to have a size substantially equal to the condensed size, it is possible to reduce leakage of reflected light from the opening 149 while preventing vignetting of the condensed incident light.

[0044] The absorbing film 150 is preferably configured to have a thickness substantially equal to the diameter of the opening 159. When the absorbing film 150 is formed thick, the wall surface of the opening 159, which is a through hole, becomes wider, and the reflected light captured by the wall surface of the opening 159 (reflected light 312 described later in FIG. 4) increases. In addition, when the absorbing film 150 is formed thick, the absorbing ability of the reflected light can be improved. This is because the absorption coefficient, which is the ratio of the incident light to the transmitted light in the absorbing film 150, is proportional to the absorbing material contained in the absorbing film 150. On the other hand, the area of ​​the opening 159 needs to be increased as the absorbing film 150 becomes thicker. This is to prevent the incident light from being eclipsed. However, when the area of ​​the opening 159 is increased, the reflected light passing through the opening 159 increases. Therefore, by disposing the absorbing film 150 with a thickness substantially equal to the diameter of the opening 159, the reflected light passing through the opening 159 can be reduced while improving the absorption coefficient of the absorbing film 150.

[0045] [Plane composition of pixels] 3 is a diagram showing a configuration example of a pixel according to the first embodiment of the present disclosure. The figure is a top view showing a configuration example of a pixel 100 arranged in a pixel array unit 10, and shows the arrangement of an on-chip lens 180 and an absorbing film 150. In the figure, the dashed dotted line represents the shape of the bottom surface of the on-chip lens 180.

[0046] 1A is a diagram showing an example of a pixel 100 in which an on-chip lens 180 formed on a circular bottom surface is disposed. The solid line circle in FIG. 1A represents an opening 159 in an absorbing film 150.

[0047] 1B shows an example of a pixel 100 in which an on-chip lens 180 is arranged on a rectangular bottom surface. In FIG. 1B, an opening 159 of an absorbing film 150 can be configured in a rectangular shape.

[0048] In this way, the opening 159 of the absorbing film 150 can be changed in accordance with the shape of the bottom surface of the on-chip lens 180. The opening 149 of the reflective film 140 can also be configured to have the same shape as the opening 159 of the absorbing film 150.

[0049] [Reflected light absorption] FIG. 4 is a diagram showing an example of absorption of reflected light according to the first embodiment of the present disclosure. This figure shows a simplified pixel 100, and shows the trajectories of incident light and reflected light in the pixel 100. In this figure, the solid arrows show incident light, and the dashed arrows show reflected light. Incident light 301 shows incident light reflected by the separation region 130 after entering the semiconductor substrate 101. Incident light 302 shows incident light obliquely entering the pixel 100. This incident light 302 is assumed to be incident light that is indirectly incident on the pixel 100 after light from a subject is reflected by the inner surface of a housing in which the image sensor 1 is arranged, and is incident light that causes noise such as flare when imaged by the pixel 100. Such incident light 302 is absorbed by the absorbing film 150. Reflected light 311 shows reflected light that is reflected again by the reflective film 140 after entering the semiconductor substrate 101 from the wiring region 110.

[0050] On the other hand, reflected light 312 represents reflected light that passes through the opening 149 of the reflective film 140. This reflected light 312 is incident on the side surface of the opening 159 of the absorbing film 150 and is absorbed. By arranging the absorbing film 150 in this manner, leakage of reflected light to the outside of the pixel 100 can be reduced.

[0051] [Other pixel configurations] 5 is a cross-sectional view showing another configuration example of a pixel according to the first embodiment of the present disclosure. Similar to FIG. 2, this figure is a cross-sectional view showing a configuration example of a pixel 100. This figure differs from the pixel 100 in FIG. 2 in that the reflective film 140 is omitted. In the pixel 100 in FIG. 5, the above-mentioned reflected light 311 is absorbed by the absorbing film 150.

[0052] As described above, the imaging element 1 according to the first embodiment of the present disclosure can reduce reflected light from the imaging element 1 by arranging the absorbing film 150 in the pixel 100 to absorb reflected light.

[0053] <2. Second embodiment> The imaging element 1 of the above-described first embodiment is provided with an absorbing film 150 having a cylindrical opening 159. In contrast, the imaging element 1 of the second embodiment of the present disclosure is different from the above-described first embodiment in that an absorbing film having an opening shaped in accordance with the light collection of the on-chip lens 180 is provided.

[0054] [Pixel configuration] 6 is a cross-sectional view showing a configuration example of a pixel according to the second embodiment of the present disclosure. Similar to FIG. 2, this figure is a cross-sectional view showing a configuration example of a pixel 100. This pixel differs from the pixel 100 described in FIG. 2 in that an absorbing film 151 is provided instead of the absorbing film 150.

[0055] In the absorbing film 151, an opening 158 is formed instead of the opening 159. This opening 158 is an opening whose opening area differs between the side close to the on-chip lens 180 and the side close to the semiconductor substrate 101. A step is formed in the opening 158 in the figure, and the opening area on the side close to the semiconductor substrate 101 is smaller than the opening area on the side close to the on-chip lens 180. By widening the opening area on the surface close to the on-chip lens 180 and narrowing the opening area on the opposing surface in this way, it is possible to form an opening shape according to the reduction in the light collection size by the on-chip lens 180. Since the opening area on the side close to the semiconductor substrate 101 is reduced, more reflected light can be absorbed.

[0056] [Other pixel configurations] 7 is a cross-sectional view showing another example of the configuration of a pixel according to the second embodiment of the present disclosure. The absorbing film 151 in this figure is different from the absorbing film 151 in FIG. 6 in that an opening 158 configured in a tapered shape is arranged. Since no step is formed in the opening 158 in this figure, vignetting of incident light does not occur at the step portion. This makes it possible to further reduce the opening area on the side close to the semiconductor substrate 101, and improve the absorption efficiency of reflected light.

[0057] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0058] As described above, the image sensor 1 according to the second embodiment of the present disclosure is provided with the absorbing film 151 having the openings 158 whose opening area on the surface adjacent to the semiconductor substrate 101 is smaller than the opening area on the surface adjacent to the on-chip lens 180. This makes it possible to absorb more reflected light and further reduce leakage of reflected light.

[0059] <3. Third embodiment> The imaging element 1 according to the above-described second embodiment absorbs reflected light by the absorbing film 151. In contrast, the imaging element 1 according to the third embodiment of the present disclosure differs from the above-described second embodiment in that reflected light is absorbed by a plurality of stacked absorbing films.

[0060] [Pixel configuration] Fig. 8 is a cross-sectional view showing a configuration example of a pixel according to the third embodiment of the present disclosure. Like Fig. 7, this figure is a cross-sectional view showing a configuration example of a pixel 100. This figure differs from the pixel 100 described in Fig. 7 in that it includes absorbing films 152 and 153 instead of the absorbing film 151.

[0061] The absorbing film 152 is an absorbing film configured to have a relatively low ratio of the absorbing member to the resin and a relatively large thickness. An opening 158 similar to that of the absorbing film 151 is formed in the absorbing film 152. On the other hand, the absorbing film 153 is an absorbing film configured to have a relatively high ratio of the absorbing member to the resin and a relatively small thickness. An opening 157 having the same diameter as the opening 158 on the side close to the on-chip lens 180 can be arranged in the absorbing film 153. In this way, a plurality of absorbing films 152 and 153 having different absorption coefficients are arranged in the pixel 100 in the figure.

[0062] As described above, the absorbing films 152 and 153 can be formed by dispersing an absorbing material such as a pigment in a resin, and the absorption coefficient can be improved as the content of the absorbing material increases. However, an absorbing film in which a large amount of absorbing material is dispersed is difficult to process. Specifically, etching the absorbing film 152 to form the opening 158 becomes difficult. This is because pigments are more difficult to etch than resins. Therefore, the content of the absorbing material in the absorbing film 152, which is formed to a relatively thick film thickness and has a tapered opening 158, is reduced. An absorbing film 153, which is formed to a thin film thickness and has an increased content of the absorbing material, is laminated on this absorbing film 152. This allows an absorbing film that can be easily processed to be arranged while maintaining the ability to absorb reflected light.

[0063] [Reflected light absorption] 9 is a diagram showing an example of absorption of reflected light according to the third embodiment of the present disclosure. Similar to FIG. 4, this diagram shows the trajectory of reflected light in the pixel 100. Of the reflected light passing through the opening 148 of the reflective film 140, reflected light 321 incident at a deep incident angle to the absorbing film 152 is absorbed by the absorbing film 152. On the other hand, reflected light 322 incident at a shallow angle to the absorbing film 152 passes through the absorbing film 152. However, it then enters the absorbing film 153 and is absorbed.

[0064] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the second embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0065] As described above, the imaging element 1 according to the third embodiment of the present disclosure can arrange a plurality of absorbing films having different absorption coefficients, thereby enabling the arrangement of absorbing films that can be easily processed while maintaining the ability to absorb reflected light.

[0066] <4. Fourth embodiment> The image sensor 1 according to the first embodiment described above absorbs the reflected light reflected by the semiconductor substrate 101 and the wiring region 110. In contrast, the image sensor 1 according to the fourth embodiment of the present disclosure differs from the first embodiment described above in that the image sensor 1 absorbs the reflected light after scattering it.

[0067] [Pixel configuration] Fig. 10 is a cross-sectional view showing a configuration example of a pixel according to a fourth embodiment of the present disclosure. Similar to Fig. 2, this figure is a cross-sectional view showing a configuration example of a pixel 100. This pixel differs from the pixel 100 described in Fig. 2 in that it further includes a scattering portion 109 on the back surface side of the semiconductor substrate 101.

[0068] The scattering portion 109 scatters incident light and reflected light. The scattering portion 109 in the figure is composed of unevenness formed on the back surface of the semiconductor substrate 101, and is disposed near the opening 159 of the absorbing film 150. The absorbing film 150 in the figure absorbs the reflected light scattered by the scattering portion 109. The reflected light that is not absorbed by the absorbing film 150 and leaks outside the pixel 100 is scattered by the scattering portion 109, and is thus dispersed and irradiated over a wide range. This makes it possible to make flare and the like less noticeable. The scattering portion 109 can be formed, for example, by partially etching the back surface of the semiconductor substrate 101.

[0069] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0070] As described above, the image sensor 1 according to the fourth embodiment of the present disclosure has the scattering sections 109 disposed therein to scatter reflected light leaking from the pixels 100. This can further improve the image quality.

[0071] <5. Fifth embodiment> In the image sensor 1 according to the first embodiment described above, the reflective film 140 is disposed on the back surface side of the semiconductor substrate 101. In contrast, the image sensor 1 according to the fifth embodiment of the present disclosure differs from the first embodiment described above in that a reflective film is further disposed on the front surface side of the semiconductor substrate 101.

[0072] [Pixel configuration] Fig. 11 is a cross-sectional view showing a configuration example of a pixel according to a fifth embodiment of the present disclosure. Similar to Fig. 2, this figure is a cross-sectional view showing a configuration example of a pixel 100. This figure differs from the pixel 100 described in Fig. 2 in that a reflective film 120 is further provided on the front side of the semiconductor substrate 101.

[0073] The reflective film 120 reflects transmitted light. The reflective film 120 is disposed in the wiring region 110, and is configured to cover the front surface side of the semiconductor substrate 101 of the pixel 100. By disposing the reflective film 120, the transmitted light transmitted through the semiconductor substrate 101 can be reflected toward the semiconductor substrate 101. This makes it possible to increase the incident light that contributes to photoelectric conversion. Compared to the image sensor 1 of FIG. 2, the conversion efficiency of the pixel 100 can be improved. The reflective film 120 can be made of metal like the reflective film 140. The reflective film 120 can also be made of the wiring layer 112. The reflective film 120 is an example of a second reflective film described in the claims.

[0074] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0075] As described above, the imaging element 1 according to the fifth embodiment of the present disclosure reflects transmitted light toward the semiconductor substrate 101 by providing the reflective film 120. This can improve the conversion efficiency.

[0076] <6. Sixth embodiment> In the imaging element 1 of the above-described fourth embodiment, the scattering section 109 is disposed on the back surface of the semiconductor substrate 101. In contrast, the imaging element 1 of the sixth embodiment of the present disclosure differs from the above-described fourth embodiment in that the scattering section is disposed on the front surface side of the semiconductor substrate 101.

[0077] [Pixel configuration] Fig. 12 is a cross-sectional view showing a configuration example of a pixel according to a sixth embodiment of the present disclosure. Similar to Fig. 2, this figure is a cross-sectional view showing a configuration example of a pixel 100. This pixel differs from the pixel 100 described in Fig. 2 in that it further includes a scattering portion 121 in the wiring region 110.

[0078] The scattering section 121 reflects and scatters the incident light transmitted through the semiconductor substrate 101. The scattering section 121 in the figure can be disposed in the wiring region 110 adjacent to the surface of the semiconductor substrate 101. For example, a metal film having irregularities formed thereon can be used for the scattering section 121. In this case, the scattering section 121 can be made of the same metal material as the wiring layer 112. By disposing the scattering section 121, the incident light transmitted through the semiconductor substrate 101 is reflected and re-enters the semiconductor substrate 101. This can improve the conversion efficiency of the pixel 100. In addition, since the reflected light from the scattering section 121 is scattered, even if the light leaks from the pixel 100, it is possible to make flare and the like less noticeable. The scattering section 121 can be formed, for example, by etching the surface of the insulating layer 111 to form irregularities and then laminating a metal film on the irregularities.

[0079] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the fourth embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0080] As described above, the image sensor 1 according to the sixth embodiment of the present disclosure has the scattering section 121 arranged to reflect light transmitted through the semiconductor substrate 101 and to scatter reflected light leaking from the pixel 100. This makes it possible to improve the conversion efficiency while improving the image quality.

[0081] <7. Seventh embodiment> In the image sensor 1 according to the first embodiment described above, incident light of all wavelengths is incident on the photoelectric conversion unit of the pixel 100. In contrast, the image sensor 1 according to the seventh embodiment of the present disclosure is different from the first embodiment described above in that a color filter is provided for each pixel 100 to select incident light.

[0082] [Pixel configuration] Fig. 13 is a cross-sectional view showing a configuration example of a pixel according to a seventh embodiment of the present disclosure. The same figure is a cross-sectional view showing a configuration example of a pixel, similar to Fig. 2. The pixel 100 includes a color filter 170, and is different from the pixel 100 described in Fig. 2 in that the pixel 100 includes a pixel 200.

[0083] The pixel 100 in the figure includes a color filter 170. The color filter 170 is an optical filter that transmits incident light of a predetermined wavelength. For example, a color filter 170 that transmits red light, green light, and blue light can be used as the color filter 170. A color filter 170 corresponding to any of these can be arranged in the pixel 100. The on-chip lens 180 in the figure focuses the incident light on a photoelectric conversion unit through the color filter 170. The photoelectric conversion unit generates an image signal of the incident light of the wavelength corresponding to the color filter 170. By arranging the pixel 100 including the color filter 170, a color image can be obtained. In addition, a color filter that transmits infrared light can also be arranged as the color filter 170.

[0084] In addition, the color filter 170 of the pixel 100 may be arranged with a color filter 170 that transmits incident light with a relatively long wavelength. Specifically, the color filter 170 that transmits infrared light and red light may be arranged in the pixel 100. Incident light with a relatively long wavelength, such as infrared light and red light, is difficult to be absorbed by the semiconductor substrate 101 and reaches a deep portion of the semiconductor substrate 101. When the thickness of the semiconductor substrate 101 is thin, as in the back-illuminated imaging element 1 shown in the figure, incident light with a long wavelength passes through the semiconductor substrate 101 and tends to generate reflected light. For this reason, the above-mentioned absorbing film 150 and reflective film 140 are arranged in such a pixel 100 to reduce reflected light.

[0085] The pixel 200 is a pixel that includes a color filter 170 and does not include the absorbing film 150 and the reflective film 140. A protective film 160 is disposed in the region of the absorbing film 150 and the reflective film 140. The color filter 170 of the pixel 200 can be disposed with a color filter 170 that transmits incident light with a relatively short wavelength. Specifically, the color filter 170 that transmits green light and blue light can be disposed in the pixel 200. Incident light with a relatively short wavelength, such as green light and blue light, is easily absorbed by the semiconductor substrate 101, and the ratio of the light that transmits through the semiconductor substrate 101 and generates reflected light is low. Therefore, the absorbing film 150 and the reflective film 140 of the pixel 200 in which the color filter 170 corresponding to green light and blue light is disposed can be omitted.

[0086] The configuration of the image sensor 1 is not limited to this example. For example, the absorbing film 150 and the reflective film 140 may be disposed on all pixels.

[0087] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0088] As described above, the imaging device 1 according to the seventh embodiment of the present disclosure is provided with the color filter 170, and is thereby capable of outputting a color image signal.

[0089] <8. Eighth embodiment> In the image sensor 1 according to the first embodiment described above, the opening 159 of the absorbing film 150 is disposed in the center of the pixel 100. In contrast, the image sensor 1 according to the eighth embodiment of the present disclosure differs from the first embodiment described above in that the position and shape of the opening 159 are adjusted according to the incident angle of incident light.

[0090] [Pixel configuration] Fig. 14 is a diagram showing a configuration example of a pixel according to an eighth embodiment of the present disclosure. Similar to Fig. 3, Fig. 14 is a top view showing a configuration example of a pixel 100. This differs from the pixel 100 described in Fig. 3 in that the pixel 100 has different positions of the on-chip lens 180 and the opening 159 of the absorbing film 150.

[0091] The figure shows pixels 100 arranged at the left and right ends and the center of a row in the center of the pixel array section 10 described in FIG. 1. In A in the figure, the pixel 100 arranged in the center of the pixel array section 10 can be configured similarly to the pixel 100 described in FIG. 3. In contrast, the pixel 100 arranged at the end is arranged such that the on-chip lens 180 is shifted toward the center of the pixel array section 10. The opening 159 of the absorption film 150 is also shifted toward the center of the pixel array section 10.

[0092] An image of a subject is formed on the pixel array section 10 of the image sensor 1 by a photographing lens or the like. At this time, light from the subject is incident on the pixel 100 at the center of the pixel array section 10 approximately perpendicularly. On the other hand, light from the subject is incident on the pixel 100 at the periphery of the pixel array section 10 at an angle. For this reason, a shift occurs between the light collecting position of the incident light by the on-chip lens 180 and the position of the photoelectric conversion section, and the sensitivity decreases. Therefore, the light collecting position can be adjusted by displacing the on-chip lens 180 according to the incident angle of the incident light. Such an adjustment of the position of the on-chip lens 180 is called pupil correction. The opening 159 of the absorbing film 150 is also displaced according to the incident angle of the incident light, similar to the on-chip lens 180. This makes it possible to prevent vignetting of the incident light whose collecting position has been adjusted.

[0093] FIG. 1B shows an example in which an opening 157 is arranged in the absorption film 150 instead of the opening 159. The pixel 100 in FIG. 1B has an opening 157 whose shape is adjusted according to the angle of incidence of the incident light. Specifically, the opening 157 of the pixel 100 arranged on the periphery of the pixel array section 10 is configured to have a shape that extends in the direction toward the center of the pixel array section 10. This makes it possible to prevent vignetting of the obliquely incident light.

[0094] Note that the configuration of the image sensor 1 is not limited to this example. For example, the rectangular opening 159 described in B of Fig. 3 may be applied. In this case, the position and shape of the rectangular opening 159 are adjusted according to the angle of incidence of the incident light.

[0095] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the first embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0096] As described above, the image sensor 1 according to the eighth embodiment of the present disclosure can prevent a decrease in sensitivity of the pixels 100 in the peripheral portion of the pixel array section 10 by performing pupil correction.

[0097] <9. Ninth embodiment> In the imaging element 1 according to the second embodiment described above, a reflective film 140 having an opening 148 of substantially the same size as the opening 158 of the absorbing film 151 is disposed. In contrast, an imaging element 1 according to the ninth embodiment of the present disclosure differs from the second embodiment described above in that a reflective film 140 having an opening of a different size from the opening 158 of the absorbing film 151 is disposed.

[0098] [Pixel configuration] Fig. 15 is a cross-sectional view showing a configuration example of a pixel according to the ninth embodiment of the present disclosure. Like Fig. 7, this figure is a cross-sectional view showing a configuration example of a pixel 100. This differs from the pixel 100 described in Fig. 7 in that a reflective film 140 having an opening of a different size from the opening 158 of the absorbing film 151 is disposed.

[0099] The pixel 100 on the right side of the figure is a pixel in which a reflective film 140 having an opening 148 is disposed, similar to the pixel 100 in Figure 7. In contrast, the reflective films 140 of the pixel 100a on the left side of the figure and the pixel 100b in the center are provided with an opening of a different size from the opening 158 in the absorbing film 151.

[0100] The reflective film 140 of the pixel 100a has an opening 148a of approximately the same size as the area of ​​the semiconductor substrate 101. That is, the reflective film 140 of the pixel 100a is shaped to be disposed at the boundary of the pixel 100. Therefore, in the pixel 100a, the reflection of light on the back surface side of the semiconductor substrate 101 is significantly reduced. The reflected light reflected by the wiring region 110 and transmitted through the semiconductor substrate 101 again is absorbed by the absorbing film 151. Therefore, the pixel 100a has a relatively low sensitivity.

[0101] The reflective film 140 of pixel 100b has an opening 148b that is intermediate in size relative to the openings of the reflective films 140 of pixels 100 and 100a, respectively, so that the sensitivity of pixel 100b is between that of pixels 100 and 100a.

[0102] In this way, the sensitivity of the pixel 100 can be adjusted by adjusting the size of the opening in the reflective film 140. When the opening 158 in the absorbing film 151 is configured to have a tapered shape, it is preferable to configure the opening 148 in the reflective film 140 to have a size equal to or larger than the opening 158 in the absorbing film 151. This is because vignetting of incident light can be reduced.

[0103] [Plane composition of pixels] 16 is a diagram showing a configuration example of a pixel according to the ninth embodiment of the present disclosure. Similar to FIG. 3, this figure is a top view showing a configuration example of a pixel 100. The dotted lines in this figure represent the openings of the reflective film 140. In the pixel 100, the openings 148 of the reflective film 140 overlap with the openings 158 of the absorbing film 151.

[0104] As shown in the figure, the opening 148a of the reflective film 140 of the pixel 100a occupies a wide area on the back surface of the pixel. In the pixel 100b, an opening 148b of a medium size is arranged compared to the openings of the reflective film 140 in the pixel 100 and the pixel 100a. The pixels 100, 100b, and 100a in the figure correspond to a high sensitivity pixel, a medium sensitivity pixel, and a low sensitivity pixel, respectively. By switching between these pixels depending on the amount of incident light, the dynamic range of the image sensor 1 can be expanded. It is also possible to make the image sensor 1 compatible with a so-called high dynamic range (HDR).

[0105] It should be noted that the configuration of the pixel 100 is not limited to this example. For example, the opening of the reflective film 140 may be configured to have a tapered shape. Also, the size of the opening of the reflective film 140 may be configured in multiple stages.

[0106] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the third embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0107] As described above, the imaging element 1 of the ninth embodiment of the present disclosure can adjust the sensitivity of a pixel by disposing a reflective film 140 having an opening 148 of a different size than the opening 158 of the absorbing film 151 in the pixel 100.

[0108] <10. Tenth embodiment> In the image sensor 1 of the above-described ninth embodiment, the reflective film 140 having the opening 149 of a size different from the opening 158 of the absorbing film 151 is disposed. In contrast, the image sensor 1 of the tenth embodiment of the present disclosure differs from the above-described ninth embodiment in that the wiring region 110 having the reflective film 120 is disposed.

[0109] [Pixel configuration] Fig. 17 is a cross-sectional view showing a configuration example of a pixel according to a tenth embodiment of the present disclosure. Similar to Fig. 15, this figure is a cross-sectional view showing a configuration example of a pixel 100. This figure differs from the pixel 100 described in Fig. 17 in that a reflective film 120 is further disposed on the front surface side of the semiconductor substrate 101.

[0110] The pixels 100 and 100b in the figure are provided with the reflective film 120 described in FIG. 11. This makes it possible to increase the sensitivity of the pixels 100 and 100b. On the other hand, the pixel 100a in the figure does not have the reflective film 120, and therefore the sensitivity remains low. In this way, the sensitivity of the pixel 100, etc. can be further adjusted by adding the reflective film 120 and adjusting the size.

[0111] Other than this, the configuration of the imaging element 1 is similar to the configuration of the imaging element 1 described in the ninth embodiment of the present disclosure, and therefore a description thereof will be omitted.

[0112] As described above, the imaging element 1 of the tenth embodiment of the present disclosure is capable of adjusting the sensitivity of pixels 100, etc., over a wide range by adjusting the size of the opening 148 in the reflective film 140 in the pixel 100 and the size of the reflective film 120.

[0113] The configuration of the absorbing film in the second embodiment of the present disclosure can be applied to other embodiments. Specifically, the shape of the absorbing film 151 described in Figures 6 and 7 can be applied to the absorbing films in Figures 5, 8, and 10 to 14.

[0114] The configuration of the absorbing film in the third embodiment of the present disclosure can be applied to other embodiments. Specifically, the absorbing films 152 and 153 described in Fig. 8 can be applied to the absorbing films in Figs. 5 to 7 and 10 to 15.

[0115] The pixel configuration of the fourth embodiment of the present disclosure can be applied to the other embodiments. Specifically, the scattering portion 109 described in FIG. 10 can be applied to the pixel 100 in FIGS. 5 to 8 and 11 to 14.

[0116] The pixel configuration of the fifth embodiment of the present disclosure can be applied to the other embodiments. Specifically, the reflective film 120 described in FIG. 11 can be applied to the pixel 100 in FIGS.

[0117] The pixel configuration of the sixth embodiment of the present disclosure can be applied to the other embodiments. Specifically, the scattering portion 121 described in FIG. 12 can be applied to the pixel 100 in FIGS.

[0118] The pixel configuration of the seventh embodiment of the present disclosure can be applied to other embodiments. Specifically, the color filter 170 described in FIG. 13 can be applied to the pixel 100 in FIGS. 5 to 8, 10 to 12, 14, 15, and 17. In addition, the pixels 100 and 200 described in FIG. 13 can be applied to the pixel array units 10 in FIGS. 5 to 8, 10 to 12, 14, 15, and 17.

[0119] The pixel configuration of the eighth embodiment of the present disclosure can be applied to other embodiments. Specifically, the absorbing film 150 described in FIG. 14 can be applied to the pixel 100 of FIGS. 5 to 8, 10, 13, 15 and 17.

[0120] The pixel configuration of the ninth embodiment of the present disclosure can be applied to the other embodiments. Specifically, the reflective film 140 described in FIG. 15 can be applied to the pixel 100 in FIG.

[0121] <11. Camera application example> The technology according to the present disclosure (the present technology) can be applied to various products. For example, the present technology may be realized as an imaging element mounted in an imaging device such as a camera.

[0122] 18 is a block diagram showing a schematic configuration example of a camera, which 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.

[0123] A lens 1001 is a photographing lens of the camera 1000. This lens 1001 collects light from a subject and causes it to enter an image sensor 1002 (described later) to form an image of the subject.

[0124] The image sensor 1002 is a semiconductor element that captures an image of light from a subject collected by the lens 1001. The image sensor 1002 generates an analog image signal according to the irradiated light, converts it into a digital image signal, and outputs it.

[0125] The imaging control unit 1003 controls the imaging of the imaging element 1002. The imaging control unit 1003 controls the imaging element 1002 by generating a control signal and outputting it to the imaging element 1002. The imaging control unit 1003 can also perform autofocus in the camera 1000 based on an image signal output from the imaging element 1002. Here, autofocus is a system that detects the focal position of the lens 1001 and automatically adjusts it. As this autofocus, a method (image plane phase difference autofocus) can be used in which an image plane phase difference is detected by a phase difference pixel arranged in the imaging element 1002 to detect the focal position. Also, a method (contrast autofocus) can be applied in which a position where the contrast of an image is the highest is detected as the focal position. The imaging control unit 1003 adjusts the position of the lens 1001 via the lens driving unit 1004 based on the detected focal position, and performs autofocus. The imaging control unit 1003 can be configured, for example, by a DSP (Digital Signal Processor) equipped with firmware.

[0126] The lens driving unit 1004 drives the lens 1001 under the control of the imaging control unit 1003. The lens driving unit 1004 can drive the lens 1001 by changing the position of the lens 1001 using a built-in motor.

[0127] The image processing unit 1005 processes the image signal generated by the image sensor 1002. This processing includes, for example, demosaic for generating image signals of missing colors among the image signals corresponding to red, green, and blue for each pixel, noise reduction for removing noise from the image signal, and encoding of the image signal. The image processing unit 1005 can be configured, for example, by a microcomputer equipped with firmware.

[0128] The operation input unit 1006 receives an operation input from a user of the camera 1000. For example, a push button or a touch panel can be used for this operation input unit 1006. The operation input received by the operation input unit 1006 is transmitted to the imaging control unit 1003 and the image processing unit 1005. After that, a process according to the operation input, such as a process of capturing an image of a subject, is started.

[0129] The frame memory 1007 is a memory for storing frames, which are image signals for one screen. The frame memory 1007 is controlled by the image processing unit 1005, and holds frames during the image processing process.

[0130] The display unit 1008 displays the image processed by the image processing unit 1005. For this display unit 1008, for example, a liquid crystal panel can be used.

[0131] The recording unit 1009 records the image processed by the image processing unit 1005. For this recording unit 1009, for example, a memory card or a hard disk can be used.

[0132] The above describes a camera to which the present disclosure can be applied. Of the configurations described above, the present technology can be applied to the image sensor 1002. Specifically, the image sensor 1 described in FIG. 1 can be applied to the image sensor 1002. By applying the image sensor 1 to the image sensor 1002, reflected light is reduced, and degradation in image quality of the image generated by the camera 1000 can be prevented. Note that the image processing unit 1005 is an example of a processing circuit described in the claims.

[0133] Although a camera has been described as an example here, the technology according to the present disclosure may be applied to other devices, such as a distance sensor. The present disclosure may also be applied to a semiconductor device in the form of a semiconductor module, in addition to electronic devices such as a camera. Specifically, the technology according to the present disclosure may be applied to an imaging module, which is a semiconductor module in which the imaging element 1002 and the imaging control unit 1003 in FIG. 15 are enclosed in a single package.

[0134] Finally, the above-mentioned embodiments are merely examples of the present disclosure, and the present disclosure is not limited to the above-mentioned embodiments. Therefore, even if the embodiments are different from the above-mentioned embodiments, various modifications can be made depending on the design, etc., as long as they do not deviate from the technical idea of ​​the present disclosure.

[0135] In addition, the effects described in this specification are merely examples and are not limiting, and other effects may also be obtained.

[0136] In addition, the drawings in the above-mentioned embodiments are schematic, and the dimensional ratios of the various parts do not necessarily correspond to the actual ones. In addition, the drawings may include parts whose dimensional relationships and ratios differ from one another.

[0137] The present technology can also be configured as follows. (1) an on-chip lens that focuses incident light; a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of the condensed incident light; an absorbing film disposed adjacent to the semiconductor substrate, the absorbing film having an opening having a size substantially equal to the size of the focused incident light, and absorbing reflected light of the incident light; An imaging element comprising: (2) The imaging element according to (1), further comprising a reflective film disposed between the semiconductor substrate and the absorbing film to reflect the reflected light. (3) The imaging element according to (2), wherein the reflective film has an opening of a different size from the opening of the absorbing film. (4) The image sensor according to any one of (1) to (3), wherein the absorbing film is configured in a shape in which an opening area of ​​the opening on the semiconductor substrate side is smaller than an opening area of ​​the opening on the on-chip lens side. (5) The imaging element according to (4), wherein the absorbing film has the opening configured in a tapered shape. (6) The imaging element according to any one of (1) to (5), wherein the absorption film is composed of a plurality of layers having different absorption coefficients. (7) The imaging element according to any one of (1) to (6), wherein the absorbing film is configured by dispersing an absorbing member that absorbs the incident light. (8) The imaging element according to any one of (1) to (7), wherein the absorbing film is configured to have a thickness substantially the same as a diameter of the opening. (9) The imaging element according to any one of (1) to (8), further comprising a second reflective film arranged on a side of the semiconductor substrate different from the side adjacent to the absorbing film, and reflecting the incident light that has passed through the semiconductor substrate. (10) The imaging element according to any one of (1) to (9), further comprising a scattering section that scatters the reflected light. (11) The image sensor according to (10), wherein the scattering portion is constituted by an uneven portion formed on a surface of the semiconductor substrate adjacent to the opening of the absorbing film. (12) The imaging element according to (10), wherein the scattering portion is disposed on a side of the semiconductor substrate different from the side adjacent to the absorbing film, and reflects and scatters the incident light that has passed through the semiconductor substrate. (13) The imaging element according to any one of (1) to (12), further comprising a plurality of pixels each including the on-chip lens, the photoelectric conversion portion, and the absorption film. (14) The imaging element according to (13), wherein the pixel further includes a color filter that transmits incident light of a predetermined wavelength from the incident light. (15) The imaging element according to (14), wherein the color filter transmits the incident light having a long wavelength. (16) The imaging element according to (15), wherein the color filter transmits red light. (17) The imaging element according to (15), wherein the color filter transmits infrared light. (18) The imaging element according to any one of (13) to (17), wherein the absorbing film is disposed such that the position of the opening is shifted depending on the angle of incidence of the incident light on the pixel. (19) The imaging element according to any one of (13) to (17), wherein the absorption film is configured so that the opening is extended in shape depending on an incident angle of the incident light to the pixel. (20) An on-chip lens for focusing incident light; a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of the condensed incident light; an absorbing film disposed adjacent to the semiconductor substrate, the absorbing film having an opening having a size substantially equal to the size of the focused incident light, and absorbing reflected light of the incident light; a processing circuit for processing an image signal generated based on the photoelectric conversion; An imaging device comprising: [Explanation of symbols]

[0138] 1. Image sensor 10 Pixel array section 30 Column signal processing section 100, 100a, 100b, 200 pixels 101 Semiconductor substrate 109, 121 scattering part 110 Wiring area 112 Wiring layer 130 Separation area 120, 140 reflective film 148, 148a, 148b, 149, 157~159 opening 150~153 Absorption membrane 160 Protective film 170 Color Filter 180 On-chip lens 1000 Cameras 1002 Image sensor 1005 Image processing section

Claims

1. An imaging element configured with a plurality of pixels arranged in a predetermined array, The pixel is an on-chip lens that focuses incident light; a photoelectric conversion unit formed on a semiconductor substrate and performing photoelectric conversion of incident light collected by the on-chip lens; an absorbing film that is disposed adjacent to the semiconductor substrate, has an opening that is approximately the same size as a focused size of the incident light focused by the on-chip lens, and absorbs reflected light of the incident light; a reflective film disposed between the semiconductor substrate and the absorbing film, the reflective film having an opening for transmitting the incident light focused by the on-chip lens and reflecting the reflected light, an isolation region that optically isolates the pixels is disposed at a boundary between the adjacent pixels; the reflective film and the separation region are formed as continuous parts of the same material; The absorbing film is a film in which an absorbing material that absorbs light is dispersed, and is composed of a plurality of layers having different absorption coefficients, The plurality of layers include a first absorbing film and a second absorbing film that is thinner than the first absorbing film and has a higher content of the absorbing material than the first absorbing film. Image sensor.

2. The image sensor according to claim 1 , wherein the reflective film has an opening having a size different from that of the opening of the absorbing film.

3. 3. The image sensor according to claim 1, wherein the absorbing film is configured so that an opening area of ​​the absorbing film on the semiconductor substrate side is smaller than an opening area of ​​the absorbing film on the on-chip lens side.

4. 4. The image sensor according to claim 3, wherein the opening of the absorbing film is tapered.

5. 5. The image sensor according to claim 1, wherein the absorbing film is formed to have a thickness substantially equal to a diameter of the opening of the absorbing film.

6. 6. The imaging element according to claim 1, further comprising a second reflective film arranged on a side of the semiconductor substrate different from the side adjacent to the absorption film, and reflecting the incident light that has passed through the semiconductor substrate.

7. 7. The image sensor according to claim 1, further comprising a scattering section for scattering the reflected light.

8. 8. The image sensor according to claim 7, wherein the scattering portion is constituted by an uneven portion formed on the surface of the semiconductor substrate adjacent to the opening of the absorbing film.

9. The imaging element according to claim 7 , wherein the scattering portion is disposed on a side of the semiconductor substrate different from a side on which the absorbing film is adjacent, and reflects and scatters the incident light that has passed through the semiconductor substrate.

10. 10. The image sensor according to claim 1, wherein the pixel further comprises a color filter that transmits incident light of a predetermined wavelength out of the incident light.

11. 11. The image sensor according to claim 1, wherein the absorbing film is disposed such that the position of an opening of the absorbing film is shifted according to an incident angle of the incident light to the pixel.

12. 11. The image sensor according to claim 1, wherein the absorbing film is configured so that an opening of the absorbing film is extended in accordance with an incident angle of the incident light to the pixel.

13. The imaging element according to any one of claims 1 to 12, a processing circuit for processing an image signal generated based on the photoelectric conversion.

Images