IMAGING DEVICE AND ELECTRONIC APPARATUS

An imaging device that makes it possible to achieve a reduction in size in in-plane directions without sacrificing its operation capability is provided. The imaging device includes: a base body; a pixel array unit; a first inter-identical color pixel wall member; and an inter-pixel light shielding film. The pixel array unit is one where a plurality of first color pixels and a plurality of second color pixels are disposed on the base body. The plurality of first color pixels lie adjacent to each other and each include a first color filter and a first photoelectric conversion unit that receives first color light passed through the first color filter and performs photoelectric conversion on the first color light. The plurality of second color pixels lie adjacent to each other and each include a second color filter and a second photoelectric conversion unit that receives second color light passed through the second color filter and performs photoelectric conversion on the second color light. The first inter-identical color pixel wall member is positioned in a gap among the plurality of first color filters, and has a refractive index lower than a refractive index of the first color filter. The inter-pixel light shielding film is positioned in a gap between the plurality of first color pixels and the plurality of second color pixels, and suppresses transmission of light entering the pixel array unit.

TECHNICAL FIELD

The present disclosure relates to an imaging device that performs photoelectric conversion to capture an image and an electronic apparatus including the imaging device.

BACKGROUND ART

The present applicant has proposed so far a solid-state imaging device in which a device separator having a refractive index lower than a refractive index of a color filter is provided in a gap between the color filters, respectively, in pixels adjacent to each other (for example, see PTL 1).

CITATION LIST

Patent Literature

SUMMARY OF THE INVENTION

By the way, for such an imaging device, a reduction in size in in-plane directions orthogonal to a light-entering direction has been demanded.

Therefore, what is desired is to provide an imaging device that is suitable for a reduction in size in the in-plane directions without sacrificing its operation capability, and an electronic apparatus including such an imaging device.

An imaging device according to one embodiment of the present disclosure includes: a base body; a pixel array unit; a first inter-identical color pixel wall member; and an inter-pixel light shielding film. The pixel array unit is one where a plurality of first color pixels and a plurality of second color pixels are disposed on the base body. The plurality of first color pixels lie adjacent to each other and each include a first color filter and a first photoelectric conversion unit that receives first color light passed through the first color filter and performs photoelectric conversion on the first color light. The plurality of second color pixels lie adjacent to each other and each include a second color filter and a second photoelectric conversion unit that receives second color light passed through the second color filter and performs photoelectric conversion on the second color light. The first inter-identical color pixel wall member is positioned in a gap among a plurality of the first color filters, and has a refractive index lower than a refractive index of the first color filter. The inter-pixel light shielding film is positioned in a gap between the plurality of first color pixels and the plurality of second color pixels, and suppresses light entering and passing through the pixel array unit.

Furthermore, an electronic apparatus according to the one embodiment of the present disclosure is one that includes the imaging device described above.

In the imaging device and the electronic apparatus according to the one embodiment of the present disclosure having the configuration described above, light passing through the first color filter efficiently enters the first photoelectric conversion unit. Furthermore, light entered the first color pixel becomes less likely to leak to the second color pixel, and light entered the second color pixel becomes less likely to leak to the first color pixel.

MODES FOR CARRYING OUT THE INVENTION

In the following, an embodiment of the present disclosure will be described in detail with reference to the drawings. It is to be noted that the description will be given in the following order.1. One Embodiment

This is an example of a solid-state imaging device provided with an inter-pixel light shielding film between pixels that differ from each other in color.2. Modification Examples to One Embodiment3. Application Example to Electronic Apparatus4. Application Example to Movable Body5. Practical Example to Endoscopic Surgery System6. Other Modification Examples

1. One Embodiment

FIG.1is a block diagram illustrating a configuration example of functions of a solid-state imaging device101according to a first embodiment of the present technique.

The solid-state imaging device101is, for example, one called a global shutter style, back surface irradiation type image sensor such as a complementary metal oxide semiconductor (CMOS) image sensor. The solid-state imaging device101is one that captures an image by receiving light from an object, performing photoelectric conversion on the light, and generating an image signal.

The global shutter style basically refers to a style of performing global exposure where exposure starts simultaneously on all pixels, and the exposure ends simultaneously on all the pixels. Note herein that all the pixels mean all pixels in a portion appeared on an image, excluding dummy pixels, for example. Furthermore, the global shutter style further includes such a style that, in a case where a time difference or a degree of distortion in an image is sufficiently small to an extent that it does not cause a problem to occur, global exposure is performed in a unit of a plurality of rows (for example, several ten rows), instead of simultaneously performing global exposure on all pixels, and a region on which the global exposure is performed is moved. Furthermore, the global shutter style further includes such a style that global exposure is performed on pixels in a predetermined region, instead of all pixels on a portion appeared in an image.

A back surface irradiation type image sensor refers to an image sensor having a configuration where a photoelectric conversion unit such as a photo diode that receives light from an object and converts the light into an electric signal is provided between a light-receiving surface that receives the light from the object and a wiring layer provided with wiring lines for transistors that drive pixels.

The solid-state imaging device101includes, for example, a pixel array unit111, a vertical drive unit112, a column signal processing unit113, a horizontal drive unit114, a system control unit115, pixel drive lines116, vertical signal lines117, a signal processing unit118, and a data storing unit119.

In the solid-state imaging device101, the pixel array unit111is formed on a semiconductor substrate11(described later). Peripheral circuits such as the vertical drive unit112, the column signal processing unit113, the horizontal drive unit114, the system control unit115, the signal processing unit118, and the data storing unit119are further formed on the semiconductor substrate11, identically to the pixel array unit111, for example.

The pixel array unit111has a plurality of sensor pixels110each including a photoelectric conversion unit PD (described later) that generates and accumulates electric charges in accordance with an amount of light entered from an object. The sensor pixels110are respectively disposed in horizontal directions on a paper face and vertical directions on the paper face, as illustrated inFIG.1. The horizontal directions on the paper face inFIG.1are also referred to as row directions, and the vertical directions on the paper face inFIG.1are also referred to as column directions. In the pixel array unit111, each of the pixel drive lines116is wired in the row directions per a pixel row including a plurality of the sensor pixels110disposed in a line in the row directions. In the pixel array unit111, each of the vertical signal lines117is also wired in the column directions per a pixel column including a plurality of the sensor pixels110disposed in a line in the column directions.

The vertical drive unit112includes shift resistors and address decoders, for example. The vertical drive unit112supplies signals to the plurality of sensor pixels110, respectively, via a plurality of the pixel drive lines116to drive all the plurality of sensor pixels110simultaneously in the pixel array unit111or to drive the plurality of sensor pixels110in a unit of pixel row.

The vertical drive unit112includes, for example, two scan systems that are a reading scan system and a sweeping-out scan system. The reading scan system performs selective scanning sequentially on unit pixels in the pixel array unit111in a unit of row to read signals from the unit pixels. The sweeping-out scan system performs sweeping-out scanning on rows to be read, for which reading scanning is performed by the reading scan system, antecedent to the reading scanning by a period of time corresponding to a shutter speed.

Through the sweeping-out scanning performed by the sweeping-out scan system, unnecessary electric charges are swept out from the photoelectric conversion units PD in the unit pixels in the rows to be read. This operation is called resetting. Then, a so-called electronic shutter operation is performed through sweeping out of unnecessary electric charges, that is, the resetting, performed by the sweeping-out scan system. Note herein that the electronic shutter operation refers to an operation of discarding photo-electric charges in the photoelectric conversion units PD, and of newly starting exposure, that is, of newly starting accumulation of photo-electric charges.

A signal read through a reading operation by the reading scan system corresponds to an amount of light entered through the reading operation performed immediately before or at the time of and after the electronic shutter operation. A period of time from a reading timing of a reading operation performed immediately before or a sweeping-out timing of an electronic shutter operation to a reading timing of a reading operation performed at this time corresponds to an accumulation time for photo-electric charges in a unit pixel, and is referred to as an exposure time.

The signals outputted from each of the unit pixels in the pixel rows, which have undergone the selective scanning by the vertical drive unit112, are respectively supplied to the column signal processing unit113via each of the vertical signal lines117. The column signal processing unit113performs predetermined signal processing on the signals outputted via each of the vertical signal lines117from each of the unit pixels in a selected row, per each of the pixel columns in the pixel array unit111, and temporarily retains pixel signals having undergone the signal processing.

Specifically, the column signal processing unit113includes shift resistors and address decoders, performs noise removal processing, correlation double sampling processing, and analog-to-digital (A/D) conversion processing through which analog pixel signals undergo A/D conversion, and generates digital pixel signals, for example. The column signal processing unit113supplies the generated pixel signals to the signal processing unit118.

The horizontal drive unit114includes shift resistors and address decoders, for example, to sequentially select each of unit circuits, which correspond to the pixel columns, in the column signal processing unit113. Through selective scanning performed by the horizontal drive unit114, pixel signals having undergone signal processing per unit circuit in the column signal processing unit113are sequentially outputted to the signal processing unit118.

The system control unit115includes a timing generator that generates various timing signals, for example. The system control unit115is one that performs driving control on the vertical drive unit112, the column signal processing unit113, and the horizontal drive unit114on the basis of timing signals generated by the timing generator.

The signal processing unit118is one that causes the data storing unit119to temporarily store data as necessary, performs signal processing such as computation processing on pixel signals supplied from the column signal processing unit113, and outputs an image signal including the pixel signals.

To allow the signal processing unit118to perform signal processing, the data storing unit119temporarily stores data necessary for the signal processing.

Next, a circuit configuration example of each of the sensor pixels110provided in the pixel array unit111illustrated inFIG.1will now be described with reference toFIG.2.FIG.2illustrates the circuit configuration example of one sensor pixel110among the plurality of sensor pixels110configuring the pixel array unit111.

In the example illustrated inFIG.2, the sensor pixels110in the pixel array unit111each include a photoelectric conversion unit (PD)51, a transfer transistor (TG)52, an electric charge voltage conversion unit (FD)53, a resetting transistor (RST)54, an amplifier transistor (AMP)55, and a selection transistor (SEL)56.

In this example, the TG52, the RST54, the AMP55, and the SEL56are all N-type MOS transistors. The vertical drive unit112and the horizontal drive unit114cause drive signals S52, S54, S55, and S56to be respectively supplied to gate electrodes of the TG52, the RST54, the AMP55, and the SEL56on the basis of driving control performed by the system control unit115. The drive signals S52, S54, S55, and S56are pulse signals where a high level state represents an active state (an on state) and a low level state represents an inactive state (an off state). Note that turning a drive signal into the active state will also be hereinafter referred to as turning on of the drive signal, and turning the drive signal into the inactive state will also be hereinafter referred to as turning off of the drive signal.

The PD51is a photoelectric conversion device including a photo diode having a PN junction, for example, and is configured to receive light from an object, performs photoelectric conversion on the received light, generates electric charges in accordance with an amount of the light received, and accumulates the generated electric charges.

The TG52is coupled between the PD51and the FD53, and is configured to transfer the electric charges accumulated in the PD51to the FD53in accordance with the drive signal S52applied to the gate electrode of the TG52.

The RST54has a drain coupled to a power supply VDD and a source coupled to the FD53. The RST54initializes, that is, resets the FD53in accordance with the drive signal S54applied to its gate electrode. As a drive signal S58reaches the on state, and a RST58is turned on, for example, an electric potential in the FD53is reset to a voltage level in the power supply VDD. That is, the FD53is initialized.

The FD53serves as a floating diffusion region where electric charges transferred from the PD51via the TG52are converted into and outputted as electric signals (for example, voltage signals). The FD53is coupled with the RST54, and coupled with a corresponding one of the vertical signal lines117via the AMP55and the SEL56.

(Plan Configuration Example of Pixel Array Unit111)

Next, a plan configuration example of the pixel array unit111illustrated inFIG.1will now be described with reference toFIG.3.FIG.3is a schematic plan view illustrating a plan configuration example of a portion of the pixel array unit111. The pixel array unit111includes pluralities of pixel groups disposed in a matrix on the semiconductor substrate11, for example. The pluralities of pixel groups include a plurality of red pixel groups1R, a plurality of green pixel groups1G, and a plurality of blue pixel groups1B, as illustrated inFIG.3, for example. The red pixel groups1R detect red light. The green pixel groups1G detect green light. The blue pixel groups1B detect blue light. In the example illustrated inFIG.3, the red pixel groups1R, the green pixel groups1G, and the blue pixel groups1B form a so-called Bayer layout. Note that the pluralities of pixel groups according to the present disclosure are not limited to ones that include the red pixel groups1R, the green pixel groups1G, and the blue pixel groups1B, but may include pixel groups of other colors. Furthermore, the layout of the pluralities of pixel groups according to the present disclosure is not limited to the Bayer layout illustrated inFIG.3, but may be another layout.

The plurality of red pixel groups1R each includes a plurality of red pixels R disposed in a two dimensional array of m by m in X-axis directions and Y-axis directions (m is a natural number of two or greater). InFIG.3, a case where m=2 is exemplified. In the present embodiment, it is described a case where m=2. Therefore, the plurality of red pixel groups1R each includes four red pixels R1to R4in a square array of two columns×two rows. Similarly, the plurality of green pixel groups1G each includes a plurality of green pixels G disposed in a two dimensional array of m by m in the X-axis directions and the Y-axis directions, that is, has four green pixels G1to G4disposed in a square array of two columns×two rows, as illustrated inFIG.3, for example. Similarly, the plurality of blue pixel groups1B each includes a plurality of blue pixels B disposed in a two dimensional array of m by m in the X-axis directions and the Y-axis directions, that is, has four blue pixels B1to B4in a square array of two columns×two rows, as illustrated inFIG.3, for example. Note that the red pixels R, the green pixels G, and the blue pixels G respectively correspond to the sensor pixels110described inFIGS.1and2.

(Cross-Sectional Configuration Example of Pixel Array Unit111)

Next, a cross-sectional configuration example of the pixel array unit111illustrated inFIG.1will now be described with reference toFIGS.4A and4B.FIG.4Ais a cross-sectional view illustrating a configuration example of a cross section passing through one of the red pixel groups1R and one of the green pixel groups1G, which lie adjacent to each other in the X-axis directions. Specifically, the cross section illustrated inFIG.4Acorresponds to a cross section expanding in arrow-view directions extending along an IVA-IVA cutting line illustrated inFIG.3.FIG.4Bis a cross-sectional view illustrating a configuration example of a cross section passing through one of the green pixel groups1G and one of the blue pixel groups1B, which lie adjacent to each other in the Y-axis directions. Specifically, the cross section illustrated inFIG.4Bcorresponds to a cross section expanding in arrow-view directions extending along an IVB-IVB cutting line illustrated inFIG.3. Note that the red pixels R, the green pixels G, and the blue pixels B have configurations substantially identical to each other, excluding that colors of color filters5differ from each other.

As illustrated inFIGS.4A and4B, the sensor pixels110, that is, the red pixels R forming the red pixel groups1R, the green pixels G forming the green pixel groups1G, and the blue pixels B forming the blue pixel groups1B, all respectively share the semiconductor substrate11and a wiring layer12, and all respectively have the color filters5, and on-chip lenses OCL that receive ambient light.

The semiconductor substrate11is a single crystal silicon substrate, for example. The semiconductor substrate11has a back surface11B, and a front surface11A lying on an opposite side to the back surface11B. The color filters5and the on-chip lenses OCL are sequentially laminated with each other on the back surface11B, respectively. The back surface11B serves as a light-receiving surface that receives light that has passed through the on-chip lenses OCL and the color filters5sequentially from an object.

The semiconductor substrate11is provided with the photoelectric conversion units51. The semiconductor substrate11may be further provided with fixed electric charge films13to cover the PDs51, respectively. The fixed electric charge films13have negative fixed electric charges to suppress occurrence of a dark current due to an interface level at the light-receiving surface, that is, the back surface11B of the semiconductor substrate11. Due to electric fields that the fixed electric charge films13induce, respectively, hole accumulation layers are formed at positions adjacent to the back surface11B of the semiconductor substrate11, respectively. The hole accumulation layers suppress occurrence of electrons from the back surface11B. Note that, inFIGS.4A and4B, red photoelectric conversion units51R included in the red pixels R, green photoelectric conversion units51G included in the green pixels G, and blue photoelectric conversion units51B included in the blue pixels B are respectively illustrated in a differentiated manner. In the present application, there may be a case where the red photoelectric conversion units51R, the green photoelectric conversion units51G, and the blue photoelectric conversion units51B are collectively and simply referred to as the photoelectric conversion units51.

The color filters5are provided on the back surface11B of the semiconductor substrate11. Other films including reflection preventions film and planarizing films, for example, may be respectively provided between the color filters5and the fixed electric charge films13. Note that, as illustrated inFIGS.4A and4B, the red pixels R are respectively provided with red color filters5R in a one-by-one manner. The green pixels G are respectively provided with green color filters5G in a one-by-one manner. The blue pixels B are respectively provided with blue color filters5B in a one-by-one manner. The red color filters5R mainly allow red color to pass through. The green color filters5G mainly allow green color to pass through. The blue color filters5B mainly allow blue color to pass through. In the present application, there may be a case where the red color filters5R, the green color filters5G, and the blue color filters5B are collectively and simply referred to as the color filters5.

The on-chip lenses OCL are positioned on opposite sides to the fixed electric charge films13, when seen from the color filters5, respectively, and are provided to be in contact with the color filters5, respectively.

The wiring layer12is provided to cover the front surface11A of the semiconductor substrate11, and includes the TGs52, for example, configuring, respectively, pixel circuits in the sensor pixels110illustrated inFIG.2.

As illustrated inFIGS.3,4A, and4B, the pixel array unit111further includes red inter-pixel wall members2R, green inter-pixel wall members2G, and blue inter-pixel wall members2B. Specifically, the red inter-pixel wall members2R are each provided in a gap among the four red pixels R1to R4in each of the red pixel groups1R to separate the four red pixels R1to R4from each other. Similarly, the green inter-pixel wall members2G are each provided in a gap among the four green pixels G1to G4in each of the green pixel groups1G to separate the four green pixels G1to G4from each other. Similarly, the blue inter-pixel wall members2B are each provided in a gap among the four blue pixels B1to B4in each of the blue pixel groups1B to separate the four blue pixels B1to B4from each other.

More specifically, the red inter-pixel wall members2R are each positioned in a gap among the four red color filters5R included in each of the red pixel groups1R. The red inter-pixel wall members2R each have a refractive index lower than a refractive index of each of the red color filters5R. Similarly, the green inter-pixel wall members2G are each positioned in a gap among the four green color filters5G included in each of the green pixel groups1G. The green inter-pixel wall members2G each have a refractive index lower than a refractive index of each of the green color filters5G. The blue inter-pixel wall members2B are each positioned in a gap among the four blue color filters5B included in each of the blue pixel groups1B. The blue inter-pixel wall members2B each have a refractive index lower than a refractive index of each of the blue color filters5B. The red inter-pixel wall members2R, the green inter-pixel wall members2G, and the blue inter-pixel wall members2B may each include, for example, silicon nitride (SiN), silicon oxide (SiO2), or a resin material, or may each have a void.

The pixel array unit111further includes an inter-different color pixel wall member3and an inter-pixel light shielding film4. The inter-different color pixel wall member3and the inter-pixel light shielding film4are positioned in a gap among the red pixel groups1R, the green pixel groups1G, and the blue pixel groups1B, respectively. The inter-different color pixel wall member3and the inter-pixel light shielding film4are laminated with each other in Z-axis directions. The inter-different color pixel wall member3may have, for example, a refractive index lower than the refractive index of each of the red color filters5R, the refractive index of each of the green color filters5G, and the refractive index of each of the blue color filters5B. The inter-pixel light shielding film4suppresses transmission of light entering the pixel array unit111. The inter-pixel light shielding film4includes, for example, a material containing at least one type of metal of or an oxide of one type of metal of titanium (Ti), tungsten (W), copper (Cu), or aluminum (Al). The inter-pixel light shielding film4may be provided in an identical layer to a color filter layer CF including the color filters5, or may be provided between the color filter layer CF and the PDs51in the semiconductor substrate11, in the Z-axis directions.

[Workings and Effects of Solid-State Imaging Device101]

In the solid-state imaging device101according to the present embodiment, as described above, the red inter-pixel wall members2R are each positioned in a gap among a plurality of the red color filters5R, the green inter-pixel wall members2G are each positioned in a gap among a plurality of the green color filters5G, and the blue inter-pixel wall members2B are each positioned in a gap among a plurality of the blue color filters5B. Note herein that the refractive index of each of the red inter-pixel wall members2R is lower than the refractive index of each of the red color filters5R, the refractive index of each of the green inter-pixel wall members2G is lower than the refractive index of each of the green color filters5G, and the refractive index of each of the blue inter-pixel wall members2B is lower than the refractive index of each of the blue color filters5B. Therefore, incident light that has once passed through the on-chip lenses OCL and has entered the red color filters5R is reflected at an interface between each of the red color filters5R and each of the red inter-pixel wall members2R, and easily enters desired ones of the red photoelectric conversion units51R. That is, incident light that has entered the red color filters5R becomes less likely to leak from a side end face of each of the red color filters5R to outside. Therefore, in the red pixels R, light passing through the red color filters5R efficiently enters the red photoelectric conversion units51R. Thereby, sensitivity of each of the red pixels R is improved.

Similarly, incident light that has once passed through the on-chip lenses OCL and has entered the green color filters5G is reflected at an interface between each of the green color filters5G and each of the green inter-pixel wall members2G, and easily enters desired ones of the green photoelectric conversion units51G. That is, incident light that has entered the green color filters5G becomes less likely to leak from a side end face of each of the green color filters5G to outside. Therefore, in the green pixels G, light passing through the green color filters5G efficiently enters the green photoelectric conversion units51G. Thereby, sensitivity of each of the green pixels G is improved.

Similarly, incident light that has once passed through the on-chip lenses OCL and has entered the blue color filters5B is reflected at an interface between each of the blue color filters5B and each of the blue inter-pixel wall members2B, and easily enters desired ones of the blue photoelectric conversion units51B. That is, incident light that has entered the blue color filters5B becomes less likely to leak from a side end face of each of the blue color filters5B to outside. Therefore, in the blue pixels B, light passing through the blue color filters5B efficiently enters the blue photoelectric conversion units51B. Thereby, sensitivity of each of the blue pixels B is improved.

Furthermore, in the pixel array unit111in the solid-state imaging device101, the inter-different color pixel wall member3is provided among pixels that differ from each other in color. Allowing the inter-different color pixel wall member3to have the refractive index lower than the refractive index of each of the red color filters5R, the refractive index of each of the green color filters5G, and the refractive index of each of the blue color filters5B makes it possible to further improve the sensitivity of each of the red pixels R, the sensitivity of each of the green pixels G, and the sensitivity of each of the blue pixels B. One reason of this improvement is that, for example, incident light that has once entered the red color filters5R in the red pixels R is reflected at the interface between each of the red color filters5R and the inter-different color pixel wall member3, allowing the incident light to easily enter desired ones of the red photoelectric conversion units51R. The same applies to the green pixels G and the blue pixels B.

Furthermore, in the pixel array unit111in the solid-state imaging device101, the inter-pixel light shielding film4is provided among the pixels that differ from each other in color, suppressing transmission of incident light entering the pixel array unit111. For example, the inter-pixel light shielding film4is provided in a gap between each of the red pixels R and each of the green pixels G. Therefore, even if a small amount of red light that has passed through each of the red color filters5R or a small amount of green light that has passed through each of the green color filters5G enters an inside of the inter-different color pixel wall member3, and becomes leaked light, for example, the inter-pixel light shielding film4shields the leaked light. Therefore, it is possible to prevent leaked light, which enters from a gap among the pixels that differ from each other in color, from entering each of the photoelectric conversion units51. That is, red light entered from each of the red pixels R becomes less likely to leak to each of the green pixels G, and green light entered from each of the green pixels G becomes less likely to leak to each of the red pixels R. Thereby, it is further possible to suppress occurrence of mixing of colors in the solid-state imaging device101.

With the solid-state imaging device101according to the present embodiment, it is possible to suppress mixing of colors, to efficiently take up incident light, and to improve the sensitivity of the pixel array unit, as described above. Therefore, the solid-state imaging device101makes it possible to achieve a reduction in size in the in-plane directions without sacrificing its operation capability.

2. Modification Examples to One Embodiment

FIG.5is a plan view schematically illustrating a configuration example of a portion of a pixel array unit111A serving as a first modification example to the one embodiment of the present disclosure.FIG.5corresponds toFIG.3illustrating the pixel array unit111according to the embodiment described above. Furthermore,FIGS.6A and6Beach illustrate a cross-sectional configuration example of the pixel array unit111A illustrated inFIG.5.FIG.6Acorresponds to a cross section expanding in arrow-view directions extending along a VIA-VIA cutting line illustrated inFIG.5.FIG.6Bcorresponds to a cross section expanding in arrow-view directions extending along a VIB-VIB cutting line illustrated inFIG.5. In the pixel array unit111illustrated inFIG.3, the inter-pixel light shielding film4has been provided solely around each of the red pixel groups1R, each of the green pixel groups1G, and each of the blue pixel groups1B. In the pixel array unit111A illustrated inFIG.5and other drawings, instead, the inter-pixel light shielding film4is further provided inside each of the green pixel groups1G and inside each of the blue pixel groups1B.

Specifically, the inter-pixel light shielding film4is provided under the green inter-pixel wall members2G, and is overlaid in the Z-axis directions with each of the green inter-pixel wall members2G each positioned in a gap among the four green color filters5G included in each of the green pixel groups1G. Furthermore, the inter-pixel light shielding film4is provided under the blue inter-pixel wall members2B, and is overlaid in the Z-axis directions with each of the blue inter-pixel wall members2B each positioned in a gap among the four blue color filters5B included in each of the blue pixel groups1B.

In the pixel array unit111A, it is possible to improve sensitivity with respect to red light in each of the red pixel groups1R, and to reduce mixing of colors in the green pixel groups1G and the blue pixel groups1B. In general, as a size of each pixel is reduced, light having a longer wavelength is easily diffracted. That is, red light having a longer wavelength than a wavelength of blue light or a wavelength of green light is easily diffracted. Therefore, as a size of each pixel is reduced, there is a stronger tendency of increasing an amount of red light that leaks from the red color filters5R in the red pixels R to each of the green pixels G and each of the blue pixels B. In the pixel array unit111A serving as the first modification example, the inter-pixel light shielding film4is then further provided under each of the green inter-pixel wall members2G, and the inter-pixel light shielding film4is then further provided under each of the blue inter-pixel wall members2B. Such a configuration as described above makes it possible to reduce an amount of red light that leaks to the green photoelectric conversion units51G in each of the green pixels G and to the blue photoelectric conversion units51B in each of the blue pixels B, making it possible to further reduce mixing of red color and green color and mixing of red color and blue color.

FIG.7is a plan view schematically illustrating a configuration example of a portion of a pixel array unit111B serving as a second modification example to the one embodiment of the present disclosure.FIG.7corresponds toFIG.3illustrating the pixel array unit111according to the embodiment described above. In the pixel array unit111illustrated inFIG.3, the inter-pixel light shielding film4has been provided around each of the red pixel groups1R, each of the green pixel groups1G, and each of the blue pixel groups1B. In the pixel array unit111B illustrated inFIG.7, instead, the inter-pixel light shielding films4are each provided around each of the red pixel groups1R, but the inter-pixel light shielding film4is not provided around each of the green pixel groups1G and each of the blue pixel groups1B.

In the pixel array unit111B having such a configuration as described above, it is possible to suppress entry of leaked light of red light from each of the red pixel groups1R into each of the green pixel groups1G and each of the blue pixel groups1B. Furthermore, it is possible to further improve the sensitivity of each of the green pixel groups1G and each of the blue pixel groups1B, compared with the pixel array unit111illustrated inFIG.3.

FIG.8Ais a cross-sectional view illustrating, in an enlarged manner, a configuration example of one of the red inter-pixel wall members2R in a pixel array unit111C and its periphery, which serves as a third modification example to the one embodiment of the present disclosure. Furthermore,FIG.8Bis a cross-sectional view illustrating, in an enlarged manner, a configuration example of the inter-different color pixel wall member3and the inter-pixel light shielding film4in the pixel array unit111C and its periphery, which serves as the third modification example. In the pixel array unit111C, as illustrated inFIG.8A, at least side surfaces of each of the red inter-pixel wall members2R are covered with a protective film6. AlthoughFIG.8Aexemplifies one of the red inter-pixel wall members2R, the green inter-pixel wall members2G and the blue inter-pixel wall members2B may be each similarly covered with the protective film6. Furthermore, in the pixel array unit111C, as illustrated inFIG.8B, at least side surfaces of the inter-different color pixel wall member3and at least side surfaces of the inter-pixel light shielding film4are covered with a protective film7.

The protective film6and the protective film7both include an insulating material such as a silicon oxide film. However, the protective film6that covers each of the red inter-pixel wall members2R may have a refractive index higher than the refractive index of each of the red inter-pixel wall members2R and lower than the refractive index of each of the red color filters5R. Similarly, the protective film6that covers each of the green inter-pixel wall members2G may have the refractive index higher than the refractive index of each of the green inter-pixel wall members2G and lower than the refractive index of each of the green color filters5G. The protective film6that covers each of the blue inter-pixel wall members2B may have the refractive index higher than the refractive index of each of the blue inter-pixel wall members2B and lower than the refractive index of each of the blue color filters5B.

The protective film7that covers the inter-different color pixel wall member3and the inter-pixel light shielding film4in the gap between each of the red pixel groups1R and each of the green pixel groups1G may have a refractive index higher than the refractive index of the inter-different color pixel wall member3and lower than both the refractive index of each of the red color filters5R and the refractive index of each of the green color filters5G. Furthermore, the protective film7that covers the inter-different color pixel wall member3and the inter-pixel light shielding film4in the gap between each of the red pixel groups1R and each of the blue pixel groups1B may have the refractive index higher than the refractive index of the inter-different color pixel wall member3and lower than both the refractive index of each of the red color filters5R and the refractive index of each of the blue color filters5B. Furthermore, the protective film7that covers the inter-different color pixel wall member3and the inter-pixel light shielding film4in the gap between each of the blue pixel groups1B and each of the green pixel groups1G may have the refractive index higher than the refractive index of the inter-different color pixel wall member3and lower than both the refractive index of each of the blue color filters5B and the refractive index of each of the green color filters5G.

3. Application Example to Electronic Apparatus

FIG.9is a block diagram illustrating a configuration example of a camera2000serving as an electronic apparatus to which the present technique is applied.

The camera2000includes an optical unit2001including a lens group, for example, an imaging device (imaging device)2002to which the solid-state imaging device101described above, for example, (hereinafter referred to as the solid-state imaging device101, for example) is applied, and a digital signal processor (DSP) circuit2003serving as a camera signal processing circuit. Furthermore, the camera2000further includes a frame memory2004, a display unit2005, a recording unit2006, a operation unit2007, and a power supply unit2008. The DSP circuit2003, the frame memory2004, the display unit2005, the recording unit2006, the operation unit2007, and the power supply unit2008are coupled to each other via a bus line2009.

The optical unit2001takes up incident light (image light) from an object, and forms an image on an imaging surface of the imaging device2002. The imaging device2002converts an amount of light of the incident light that has formed the image on the imaging surface by the optical unit2001, in a unit of pixel, into an electric signal, and outputs the converted electric signal as a pixel signal.

The display unit2005includes, for example, a panel type display machine such as a liquid crystal panel or an organic electro-luminescence (EL) panel type display machine, and displays a moving image or still image captured by the imaging device2002. The recording unit2006causes a recording medium such as a hard disk or semiconductor memory to record the moving image or still image captured by the imaging device2002.

The operation unit2007issues operation commands for various functions that the camera2000has, on the basis of operations performed by a user. The power supply unit2008appropriately supplies various power supplies serving as respective operation power supplies for the DSP circuit2003, the frame memory2004, the display unit2005, the recording unit2006, and the operation unit2007to those supply targets.

By using the solid-state imaging device101, for example, described above as the imaging device2002, it is possible to expect acquisition of a proper image, as described above.

4. Practical Example to Movable Body

It is possible to apply the technique of the present disclosure (the technique) to various products. For example, the technique of the present disclosure may be achieved as a machine mounted in any kinds of movable bodies including vehicles, electric vehicles, hybrid electric vehicles, motorcycles, bicycles, personal mobilities, airplanes, drones, ships and vessels, and robots.

The example of the vehicle control system to which it is possible to apply the technique of the present disclosure has been described. The technique of the present disclosure may be applied to the imaging unit12031, among the components described above. Specifically, it is possible to apply the solid-state imaging device101, for example, illustrated inFIG.1and other drawings to the imaging unit12031. With the imaging unit12031applied with the technique according to the present disclosure, it is possible to expect superior operation of the vehicle control system.

5. Practical Example to Endoscopic Surgery System

It is possible to apply the technique of the present disclosure (the technique) to various products. For example, the technique according to the present disclosure may be applied to an endoscopic surgery system.

FIG.13is a block diagram depicting an example of a functional configuration of the camera head11102and the CCU11201depicted inFIG.12.

The example of the endoscopic surgery system to which it is possible to apply the technique according to the present disclosure has been described. The technique according to the present disclosure may be advantageously applied to the imaging unit11402provided in the camera head11102of the endoscope11100, among the components described above, for example. With the imaging unit11402applied with the technique according to the present disclosure, it is possible to make the imaging unit11402highly sensitive, making it possible to provide the endoscope11100with a high definition property.

6. Other Modification Examples

Although the present disclosure has been described with reference to the embodiment and the modification examples, the present disclosure is not limited to the embodiment and the modification examples described above, but may be modified in a wide variety of ways. In the embodiment described above, it has been described an example case where one pixel group includes four pixels disposed in a square array of two columns×two rows, that is, an example case where m=2, for example. However, m may be 3 or greater in the present disclosure.

Furthermore, it has been exemplified one that detects and acquires, as an image, distribution of amounts of light of red light, green light, and blue light, as the imaging device according to the present disclosure. However, the present disclosure is not limited to the example. In the imaging device according to the present disclosure, it is possible to adopt an array of pixel groups represented by a pixel array unit111D serving as a fourth modification example illustrated inFIG.14, for example. Specifically, the pixel array unit111D may be one where yellow pixel groups1Y that acquire yellow light, cyan pixel groups1C that acquire cyan light, magenta pixel groups1M that acquire magenta light, and green pixel groups1G that acquire green light are each disposed in a square array of two columns×two rows. The inter-different color pixel wall member3and the inter-pixel light shielding film4are provided around each of the yellow pixel groups1Y, the cyan pixel groups1C, the magenta pixel groups1M, and the green pixel groups1G. The yellow pixel groups1Y each include four yellow pixels Y1to Y4disposed in a square array of two columns×two rows. A yellow inter-pixel wall member2Y is provided in a gap among the four yellow pixels Y1to Y4. A cyan inter-pixel wall member2C is provided in a gap among four cyan pixels C1to C4. A magenta inter-pixel wall member2M is provided in a gap among four magenta pixels M1to M4. A green inter-pixel wall member2G is provided in a gap among four green pixels G1to G4. Therefore, even in the pixel array unit111D illustrated inFIG.14, it is possible to expect effects similar to the effects of the pixel array unit111illustrated inFIG.3.

Furthermore, in the imaging device according to the present disclosure, the inter-pixel light shielding film4may extend downward than a lower surface of each of the color filters5, similar to a pixel array unit111E serving as a fifth modification example illustrated inFIG.15, for example. Note that, in the pixel array unit111E, an insulating layer14is provided between the semiconductor substrate11and the color filter layer CF. The inter-pixel light shielding film4is partially buried in the insulating layer14.

Furthermore, in the imaging device according to the present disclosure, the inter-pixel light shielding film4may be solely provided below the lower surface of each of the color filters5, similar to a pixel array unit111F serving as a sixth modification example illustrated inFIG.16, for example. Note that, in the pixel array unit111F, the inter-pixel light shielding film4provided below the inter-different color pixel wall member3is fully buried in the insulating layer14.

Furthermore, in the imaging device according to the present disclosure, the inter-pixel light shielding film4may extend downward than the lower surface of each of the color filters5, and a width of the inter-pixel light shielding film4may be narrower than a width of the inter-different color pixel wall member3, similar to a pixel array unit111G serving as a seventh modification example illustrated inFIG.17, for example.

Furthermore, in the imaging device according to the present disclosure, an inter-pixel light shielding film4A may be adopted, instead of the inter-pixel light shielding film4, similar to a pixel array unit111H serving as an eighth modification example illustrated inFIG.18, for example. The inter-pixel light shielding film4A includes a base41and a wall42. The base41has a width identical to the width of the inter-different color pixel wall member3, and is positioned below the inter-different color pixel wall member3, for example. The wall42has a width narrower than the width of the base41. At least side surfaces of the wall42are covered with the inter-different color pixel wall member3. In the pixel array unit111H, adopting the inter-pixel light shielding film4A makes it possible to further improve its sensitivity than that of the pixel array unit111, and to further improve a light shielding capability of shielding leaked light.

Furthermore, in the imaging device according to the present disclosure, the width of the inter-pixel light shielding film4may be narrower than the width of the inter-different color pixel wall member3, even in the pixel array unit111illustrated inFIG.4A, for example. Furthermore, it is possible to appropriately select a ratio of a thickness of the inter-pixel light shielding film4and a thickness of the inter-different color pixel wall member3.

With the imaging device and the electronic apparatus according to the one embodiment of the present disclosure, it is possible to suppress mixing of colors, to efficiently take up incident light, and to improve the sensitivity of the pixel array unit, as described above.

Note that the effects described in the specification are mere examples. The effects of the technique are not limited to the effects described in the specification. There may be any other effects than those described herein. Furthermore, the present technique is one that may have such configurations as described below.

An imaging device including:a base body;a pixel array unit including a plurality of first color pixels lying adjacent to each other and each including a first color filter and a first photoelectric conversion unit that receives first color light passed through the first color filter and performs photoelectric conversion on the first color light and a plurality of second color pixels lying adjacent to each other and each including a second color filter and a second photoelectric conversion unit that receives second color light passed through the second color filter and performs photoelectric conversion on the second color light, the plurality of first color pixels and the plurality of second color pixels being disposed on the base body;a first inter-identical color pixel wall member positioned in a gap among a plurality of the first color filters, the first inter-identical color pixel wall member having a refractive index lower than a refractive index of the first color filter; andan inter-pixel light shielding film positioned in a gap between the plurality of first color pixels and the plurality of second color pixels, the inter-pixel light shielding film suppressing transmission of light entering the pixel array unit.
(2)

The imaging device according to (1) described above, in which a side surface of the first inter-identical color pixel wall member is covered with a first protective film having a refractive index higher than the refractive index of the first inter-identical color pixel wall member and lower than the refractive index of the first color filter.

The imaging device according to (1) or (2) described above, further including a first inter-different color pixel wall member positioned in a gap between the first color filter and the second color filter, the first inter-different color pixel wall member being laminated together with the light shielding film, the first inter-different color pixel wall member having a refractive index lower than both the refractive index of the first color filter and a refractive index of the second color filter.

The imaging device according to any one of (1) to (3) described above, in which a side surface of the first inter-different color pixel wall member is covered with a third protective film having a refractive index higher than a refractive index of the first inter-different color pixel wall member and lower than both the refractive index of the first color filter and a refractive index of the second color filter.

The imaging device according to any one of (1) to (4) described above, further including a second inter-identical color pixel wall member positioned in a gap among a plurality of the second color filters, the second inter-identical color pixel wall member having a refractive index lower than a refractive index of the second color filter.

The imaging device according to any one of (1) to (5) described above, in which a side surface of the second inter-identical color pixel wall member is covered with a second protective film having a refractive index higher than the refractive index of the second inter-identical color pixel wall member and lower than the refractive index of the second color filter.

The imaging device according to (1), in whichthe first color pixel is a red pixel, andthe inter-pixel light shielding film is provided solely around a red pixel group including a plurality of the red pixels.
(8)

The imaging device according to any one of (1) to (7) described above, in which the first inter-identical color pixel wall member includes SiN (silicon nitride), SiO2(silicon oxide), or a resin material, or has a void.

The imaging device according to any one of (1) to (8) described above, in which the inter-pixel light shielding film includes a material containing at least one of Ti (titanium), W (tungsten), Cu (copper), Al (aluminum) or oxides thereof.

The imaging device according to any one of (1) to (9) described above, in which the inter-pixel light shielding film is provided at an identical layer to a color filter layer including the first color filter and the second color filter, or provided between the first color filter and the first photoelectric conversion unit and between the second color filter and the second photoelectric conversion unit.

An electronic apparatus including an imaging device, the imaging device including:a base body;a pixel array unit including a plurality of first color pixels lying adjacent to each other and each including a first color filter and a first photoelectric conversion unit that receives first color light passed through the first color filter and performs photoelectric conversion on the first color light and a plurality of second color pixels lying adjacent to each other and each including a second color filter and a second photoelectric conversion unit that receives second color light passed through the second color filter and performs photoelectric conversion on the second color light, the plurality of first color pixels and the plurality of second color pixels being disposed on the base body;a first inter-identical color pixel wall member positioned in a gap among a plurality of the first color filters, the first inter-identical color pixel wall member having a refractive index lower than a refractive index of the first color filter; andan inter-pixel light shielding film positioned in a gap between the plurality of first color pixels and the plurality of second color pixels, the inter-pixel light shielding film suppressing transmission of light entering the pixel array unit.

The present application claims the benefit of Japanese Priority Patent Application JP 2021-147996 filed with the Japan Patent Office on Sep. 10, 2021, the entire contents of which are incorporated herein by reference.