JP2024168191A - Photodetection device and electronic device - Google Patents

Abstract

To provide an optical detection device capable of suppressing deterioration of an autofocus performance.SOLUTION: An optical detection device comprises: a semiconductor layer that contains a plurality of cell regions in which a first photoelectric conversion element and a second photoelectric conversion element that are adjacent each other along a first direction in a plan view are constructed, and in which one surface is an element formation surface and the other surface is a light incident surface; and a refractive optical element that includes a first part having a first refraction ratio and a second part having a second refraction ratio that is higher than the first refraction ratio, and is provided at a position overlapped to each cell region in the plan view in a light incident surface side. One refraction optical element includes the first part at the position which is near to the first photoelectric conversion element along the first direction, and includes the second part at the position which is near to the second photoelectric conversion element. The other one refractive optical element includes the second part at the position which is near to the first photoelectric conversion element along the first direction, and includes the first part at the position which is near to the second photoelectric conversion element.SELECTED DRAWING: Figure 4A

Description

This technology (technology related to the present disclosure) relates to a photodetection device and electronic device, and in particular to a photodetection device and electronic device having phase difference pixels.

As a phase difference pixel, for example, the DUAL PD method is known, in which two photoelectric conversion elements, one on the left and one on the right, are paired to form one pixel (see, for example, Non-Patent Document 1). In the DUAL PD method, a pair of photoelectric conversion elements share a single on-chip lens, so that separate incident light enters the left and right photoelectric conversion elements, making it possible to obtain a phase difference. Furthermore, when used as an image signal, the effects of the phase difference can be cancelled out by adding the information from the left and right photoelectric conversion elements. The DUAL PD method can be used as the basic method for all-pixel autofocus.

https://www.sony-semicon.com/ja/technology/mobile/autofocus.html

The separation ratio, which is one of the indicators of autofocus performance, may decrease as pixels become smaller.

The purpose of this technology is to provide a photodetection device and electronic device that suppresses degradation of autofocus performance.

A photodetector according to one aspect of the present technology includes a semiconductor layer including a plurality of cell regions in which a first photoelectric conversion element and a second photoelectric conversion element are arranged adjacent to each other along a first direction in a plan view, and one surface of the semiconductor layer is an element formation surface and the other surface is a light incidence surface, and a refractive optical element having a first portion having a first refractive index and a second portion having a second refractive index higher than the first refractive index, and provided at a position overlapping the cell region in a plan view on the light incidence surface side, one of the refractive optical elements having the first portion at a position closer to the first photoelectric conversion element and the second portion at a position closer to the second photoelectric conversion element along the first direction, and another of the refractive optical elements having the second portion at a position closer to the first photoelectric conversion element and the first portion at a position closer to the second photoelectric conversion element along the first direction. A photodetector.

An electronic device according to one aspect of the present technology includes the above-described light detection device and an optical system that focuses image light from a subject on the light detection device.

1 is a chip layout diagram showing a configuration example of a photodetector according to a first embodiment of the present technology. 1 is a block diagram showing a configuration example of a light detection device according to a first embodiment of the present technology. 2 is an equivalent circuit diagram of a pixel of the photodetection device according to the first embodiment of the present technology. 1 is a longitudinal sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a first embodiment of the present technology. 1 is a longitudinal sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a first embodiment of the present technology. 2 is a plan view showing a planar configuration of a refractive optical element included in the light detection device according to the first embodiment of the present technology. FIG. 10 is a diagram showing the sensitivity, relative to the incident angle of light, of a photoelectric conversion element configured in a left cell region in the photodetector according to the first embodiment of the present technology. FIG. 10 is a diagram showing the sensitivity, relative to the incident angle of light, of a photoelectric conversion element configured in a right-side cell region in the photodetector according to the first embodiment of the present technology. FIG. 2 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in the photodetection device according to the first embodiment of the present technology. FIG. 3 is an explanatory diagram of a cell region observed from a second surface side in the light detection device according to the first embodiment of the present technology; FIG. 1 is a longitudinal sectional view showing a sectional configuration of a pixel included in a photodetection device according to a comparative example. 13 is a diagram showing the sensitivity of a photoelectric conversion element formed in a cell region to the angle of incidence of light in a photodetector according to a comparative example. FIG. 1 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a first modified example of the first embodiment of the present technology. FIG. 11 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a second modified example of the first embodiment of the present technology. FIG. 11 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a third modified example of the first embodiment of the present technology. FIG. 11 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a third modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a fourth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a fourth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a fifth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a fifth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a sixth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a seventh modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to Modification 8 of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a ninth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a tenth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a modified example 11 of the first embodiment of the present technology. FIG. 13 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a twelfth modified example of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a fourteenth modification of the first embodiment of the present technology. FIG. 16 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a fourteenth modification of the first embodiment of the present technology. FIG. 15 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a fifteenth modification of the first embodiment of the present technology. FIG. 15 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a fifteenth modification of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a sixteenth modification of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a seventeenth modification of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to Modification 18 of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to Modification 18 of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a nineteenth modification of the first embodiment of the present technology. FIG. 13 is a longitudinal sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a twentieth modification of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a twenty-first modification of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a twenty-first modification of the first embodiment of the present technology. FIG. 23A to 23C are longitudinal cross-sectional views showing cross-sectional configurations at different image height positions of a pixel included in a photodetection device according to a twenty-second modification of the first embodiment of the present technology. 23A to 23C are plan views showing planar configurations at different image height positions of a refractive optical element included in a light detection device according to a twenty-second modification of the first embodiment of the present technology. 23 is an explanatory diagram of a cell region observed from the second surface side in a photodetector according to Modification 23 of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a twenty-fourth modification of the first embodiment of the present technology. FIG. 23 is a longitudinal sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a twenty-fifth modification of the first embodiment of the present technology. FIG. 23 is an explanatory diagram of a cell region observed from the second surface side in a photodetector according to Modification 26 of the first embodiment of the present technology. FIG. 23 is an explanatory diagram of a cell region observed from the second surface side in a photodetector according to Modification 27 of the first embodiment of the present technology. FIG. 23 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to Modification 28 of the first embodiment of the present technology. FIG. 23 is an explanatory diagram of a cell region observed from the second surface side in a photodetector according to Modification 28 of the first embodiment of the present technology. FIG. 23 is a longitudinal sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a twenty-ninth modified example of the first embodiment of the present technology. FIG. 13 is a longitudinal sectional view showing a sectional configuration of a pixel included in a photodetection device according to a thirty-first modification of the first embodiment of the present technology. FIG. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a thirty-second modification of the first embodiment of the present technology. FIG. 13 is a longitudinal sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a thirty-third modification of the first embodiment of the present technology. FIG. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a thirty-fourth modification of the first embodiment of the present technology. FIG. FIG. 38B is a partially enlarged view of FIG. 38A. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a thirty-fifth modification of the first embodiment of the present technology. FIG. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a thirty-sixth modified example of the first embodiment of the present technology. FIG. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to Modification 37 of the first embodiment of the present technology. FIG. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to a thirty-ninth modified example of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to a modified example 40 of the first embodiment of the present technology. FIG. 41 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to a modified example 41 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to Modification 42 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetection device according to Modification 43 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetection device according to Modification 44 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to Modification 45 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to Modification 46 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to Modification 47 of the first embodiment of the present technology. FIG. 13 is a longitudinal cross-sectional view showing a cross-sectional configuration of a pixel included in a photodetection device according to Modification 48 of the first embodiment of the present technology. FIG. 48 is a plan view showing a planar configuration of a refractive optical element included in a light detection device according to a modified example 48 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetection device according to Modification 48 of the first embodiment of the present technology. FIG. 13 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to a fourth modified example of the first embodiment of the present technology. FIG. 11 is a plan view showing an arrangement of color filters and microlenses with respect to pixels in a photodetector according to a modified example 50 of the first embodiment of the present technology. FIG. 1 is a block diagram showing an example of the configuration of an electronic device having a solid-state imaging device to which the technology according to the present disclosure is applied. 1 is a block diagram showing an example of a schematic configuration of a vehicle control system; 4 is an explanatory diagram showing an example of the installation positions of an outside-vehicle information detection unit and an imaging unit; FIG.

Below, a preferred embodiment for implementing the present technology will be described with reference to the drawings. Note that the embodiment described below is an example of a representative embodiment of the present technology, and is not intended to narrow the scope of the present technology.

In the following description of the drawings, the same or similar parts are given the same or similar reference numerals. However, it should be noted that the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc., differ from the actual ones. Therefore, specific thicknesses and dimensions should be determined by taking into consideration the following explanation. Furthermore, the drawings naturally include parts with different dimensional relationships and ratios. Furthermore, because drawings suitable for explaining this technology have been adopted, there may be differences in configuration between the drawings.

The embodiments shown below are merely examples of devices and methods for embodying the technical ideas of the present technology, and the technical ideas of the present technology do not specify the materials, shapes, structures, arrangements, etc. of the components as described below. The technical ideas of the present technology can be modified in various ways within the technical scope defined by the claims.

In addition, the definitions of directions such as up and down in the following explanation are merely for the convenience of explanation and do not limit the technical ideas of this disclosure. For example, if an object is rotated 90 degrees and observed, up and down are converted into left and right and read, and of course, if it is rotated 180 degrees and observed, up and down are read inverted.

The explanation will be given in the following order.
1. First embodiment 2. Second embodiment Application example to electronic device Application example to mobile object

[First embodiment]
In this embodiment, an example in which the present technology is applied to a photodetector device that is a back-illuminated complementary metal oxide semiconductor (CMOS) image sensor will be described.

<Overall configuration of the photodetector>
First, the overall configuration of the photodetection device 1 will be described. As shown in Fig. 1, the photodetection device 1 according to the first embodiment of the present technology is mainly composed of a semiconductor chip 2 having a rectangular two-dimensional planar shape when viewed in a plane. That is, the photodetection device 1 is mounted on the semiconductor chip 2. As shown in Fig. 54, the photodetection device 1 takes in image light (incident light 1022) from a subject via an optical system (optical lens) 1011, converts the amount of incident light 1022 imaged on an imaging surface into an electrical signal on a pixel-by-pixel basis, and outputs the electrical signal as a pixel signal.

As shown in FIG. 1, the semiconductor chip 2 on which the photodetector 1 is mounted has a square pixel region 2A located in the center of a two-dimensional plane including the X and Y directions that intersect with each other, and a peripheral region 2B located outside the pixel region 2A so as to surround the pixel region 2A.

The pixel region 2A is a light receiving surface that receives light collected by the optical system 1011 shown in FIG. 54, for example. In the pixel region 2A, a plurality of pixels 3 are arranged in a matrix in a two-dimensional plane including the X direction (row direction) and the Y direction (column direction). In other words, the pixels 3 are repeatedly arranged in each of the X direction and the Y direction that intersect with each other in the two-dimensional plane. In this embodiment, the X direction and the Y direction are orthogonal to each other, as an example. The direction orthogonal to both the X direction and the Y direction is the Z direction (thickness direction, stacking direction). The direction perpendicular to the Z direction is the horizontal direction.

As shown in FIG. 1, a plurality of bonding pads 14 are arranged in the peripheral region 2B. Each of the plurality of bonding pads 14 is arranged, for example, along each of the four sides of the semiconductor chip 2 in a two-dimensional plane. Each of the plurality of bonding pads 14 is an input/output terminal used to electrically connect the semiconductor chip 2 to an external device.

<Logic circuit>
2, the semiconductor chip 2 includes a logic circuit 13. The logic circuit 13 includes a vertical drive circuit 4, a column signal processing circuit 5, a horizontal drive circuit 6, an output circuit 7, and a control circuit 8. The logic circuit 13 is configured of a CMOS (Complementary MOS) circuit having, as field effect transistors, for example, an n-channel conductivity type MOSFET (Metal Oxide Semiconductor Field Effect Transistor) and a p-channel conductivity type MOSFET.

The vertical drive circuit 4 is composed of, for example, a shift register. The vertical drive circuit 4 sequentially selects the desired pixel drive lines 10, supplies pulses to the selected pixel drive lines 10 for driving the pixels 3, and drives each pixel 3 row by row. That is, the vertical drive circuit 4 sequentially selects and scans each pixel 3 in the pixel area 2A vertically row by row, and supplies pixel signals from the pixels 3 based on signal charges generated by the photoelectric conversion elements of each pixel 3 according to the amount of light received to the column signal processing circuit 5 through the vertical signal lines 11.

The column signal processing circuit 5 is arranged, for example, for each column of pixels 3, and performs signal processing such as noise removal for each pixel column on signals output from one row of pixels 3. For example, the column signal processing circuit 5 performs signal processing such as CDS (Correlated Double Sampling) and AD (Analog Digital) conversion to remove pixel-specific fixed pattern noise. A horizontal selection switch (not shown) is provided at the output stage of the column signal processing circuit 5 and connected between it and the horizontal signal line 12.

The horizontal drive circuit 6 is composed of, for example, a shift register. The horizontal drive circuit 6 sequentially outputs horizontal scanning pulses to the column signal processing circuits 5, thereby selecting each of the column signal processing circuits 5 in turn, and causing each of the column signal processing circuits 5 to output a pixel signal that has been subjected to signal processing to the horizontal signal line 12.

The output circuit 7 processes and outputs pixel signals sequentially supplied from each of the column signal processing circuits 5 through the horizontal signal line 12. For example, the signal processing may include buffering, black level adjustment, column variation correction, various types of digital signal processing, etc.

The control circuit 8 generates clock signals and control signals that serve as the basis for the operation of the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc., based on the vertical synchronization signal, horizontal synchronization signal, and master clock signal. The control circuit 8 then outputs the generated clock signals and control signals to the vertical drive circuit 4, column signal processing circuit 5, horizontal drive circuit 6, etc.

<Pixels>
3, each of the pixels 3 includes a photoelectric conversion unit 16. The photoelectric conversion unit 16 includes photoelectric conversion elements PD1 and PD2, charge accumulation regions (floating diffusions) FD1 and FD2 that accumulate (hold) signal charges photoelectrically converted by the photoelectric conversion elements PD1 and PD2, and transfer transistors TR1 and TR2 that transfer the signal charges photoelectrically converted by the photoelectric conversion elements PD1 and PD2 to the charge accumulation regions FD1 and FD2. Each of the pixels 3 includes a readout circuit 15 electrically connected to the photoelectric conversion unit 16, more specifically, to the charge accumulation regions FD1 and FD2.

Each of the two photoelectric conversion elements PD1 and PD2 generates a signal charge according to the amount of light received. The photoelectric conversion elements PD1 and PD2 also temporarily accumulate (hold) the generated signal charge. The cathode side of the photoelectric conversion element PD1 is electrically connected to the source region of the transfer transistor TR1, and the anode side is electrically connected to a reference potential line (e.g., ground). The cathode side of the photoelectric conversion element PD2 is electrically connected to the source region of the transfer transistor TR2, and the anode side is electrically connected to a reference potential line (e.g., ground). For example, photodiodes are used as the photoelectric conversion elements PD1 and PD2.

Of the two transfer transistors TR1 and TR2, the drain region of the transfer transistor TR1 is electrically connected to the charge storage region FD1. The gate electrode of the transfer transistor TR1 is electrically connected to the transfer transistor drive line of the pixel drive line 10 (see FIG. 2). The drain region of the transfer transistor TR2 is electrically connected to the charge storage region FD2. The gate electrode of the transfer transistor TR2 is electrically connected to the transfer transistor drive line of the pixel drive line 10.

Of the two charge storage regions FD1 and FD2, the charge storage region FD1 temporarily accumulates and holds the signal charge transferred from the photoelectric conversion element PD1 via the transfer transistor TR1. The charge storage region FD2 temporarily accumulates and holds the signal charge transferred from the photoelectric conversion element PD2 via the transfer transistor TR2.

The readout circuit 15 reads out the signal charges stored in the charge storage regions FD1 and FD2, and outputs a pixel signal based on the signal charges. The readout circuit 15 includes, but is not limited to, an amplification transistor AMP, a selection transistor SEL, and a reset transistor RST as pixel transistors. These transistors (AMP, SEL, RST) are configured as MOSFETs having, for example, a gate insulating film made of a silicon oxide film (SiO ₂ film), a gate electrode, and a pair of main electrode regions functioning as a source region and a drain region. In addition, these transistors may be MISFETs (Metal Insulator Semiconductor FETs) whose gate insulating film is made of a silicon nitride film (Si ₃ N ₄ film) or a laminated film such as a silicon nitride film and a silicon oxide film.

The source region of the amplification transistor AMP is electrically connected to the drain region of the selection transistor SEL, and the drain region is electrically connected to the power supply line Vdd and the drain region of the reset transistor. The gate electrode of the amplification transistor AMP is electrically connected to the charge storage regions FD1 and FD2 and the source region of the reset transistor RST.

The source region of the selection transistor SEL is electrically connected to the vertical signal line 11 (VSL), and the drain is electrically connected to the source region of the amplification transistor AMP. The gate electrode of the selection transistor SEL is electrically connected to the selection transistor drive line of the pixel drive line 10 (see FIG. 2).

The source region of the reset transistor RST is electrically connected to the charge storage regions FD1 and FD2 and the gate electrode of the amplification transistor AMP, and the drain region is electrically connected to the power supply line Vdd and the drain region of the amplification transistor AMP. The gate electrode of the reset transistor RST is electrically connected to the reset transistor drive line of the pixel drive line 10 (see FIG. 2).

An electronic device equipped with a photodetector 1 performs autofocus based on the phase difference between the signal charges accumulated in the two photoelectric conversion elements PD1 and PD2. When the focus is not correct, a phase difference occurs between the amount Q1 of signal charge accumulated in the photoelectric conversion element PD1 and the amount Q2 of signal charge accumulated in the photoelectric conversion element PD2. The electronic device adjusts the focus by performing operations such as manipulating the objective lens to reduce the phase difference.

After the focus adjustment is completed, the electronic device generates an image based on the sum signal charge Q3 (Q3 = Q1 + Q2), which is the sum of the amount of signal charge Q1 accumulated in the photoelectric conversion element PD1 and the amount of signal charge Q2 accumulated in the photoelectric conversion element PD2. In other words, the sum signal charge Q3 corresponds to the pixel signal.

Overview
The photodetector according to the comparative example shown in FIG. 5A is a dual PD type photodetector. In the dual PD type photodetector, for example, a pair of left and right photoelectric conversion elements PDL and PDR are configured in one pixel 3. Such pixels 3 are arranged in a matrix in the pixel region 2A (see FIG. 1). For example, such pixels 3 are arranged over the entire surface or almost the entire surface of the pixel region 2A. Also, as shown in FIG. 5A, in the dual PD type photodetector, a microlens 51 is provided for each pixel 3, and one microlens 51 is shared by a pair of photoelectric conversion elements PDL and PDR in the same pixel. In the photoelectric conversion elements PDL and PDR, signal charges are generated according to the amount of light incident thereon. Then, the phase difference between the output of the left photoelectric conversion element PDL and the output of the right photoelectric conversion element PDR in the pixel region 2A is obtained, and the optical lens is driven based on the obtained phase difference to adjust the focus. In this way, the pixel for obtaining the phase difference is called a phase difference pixel.

The separation ratio can be cited as one index of autofocus performance that utilizes phase difference. Figure 5B is a diagram showing the change in sensitivity of the photoelectric conversion elements PDL and PDR with respect to the angle of incidence of light. The separation ratio is the sensitivity difference A between the sensitivity of the left photoelectric conversion element PDL and the sensitivity of the right photoelectric conversion element PDR, and may be expressed as the ratio of one sensitivity divided by the other. The larger this sensitivity difference A is, the higher the separation ratio is. In other words, the larger the sensitivity difference A is, the higher the autofocus performance is.

In addition, in recent years, pixels have been further miniaturized. If pixels are further miniaturized, the effect of light diffraction by the microlens 51 may not be sufficient when collecting incident light within the pixel 3. For example, as shown in FIG. 5A, when light L is incident on the pixel 3 from the upper right to the lower left of the page, if it becomes difficult to sufficiently reduce the size of the light spot due to lens performance, it becomes difficult to sufficiently collect the light L on the left photoelectric conversion element PDL, and there is a possibility that the light leaking to the right photoelectric conversion element PDR will increase. If this happens, it is expected that the sensitivity of the photoelectric conversion elements PDL and PDR will change from the state shown by the dotted line to the state shown by the solid line, as shown in FIG. 5B, and the sensitivity difference A will become smaller.

<Specific configuration of the light detection device>
Next, a specific configuration of the photodetector 1 according to the first embodiment of the present technology will be described with reference to Fig. 4A to Fig. 4G. The photodetector according to the first embodiment of the present technology is a dual PD type photodetector.

<Layer structure of photodetector>
As shown in FIG. 4A, the light detection device 1 (semiconductor chip 2) has a semiconductor layer 20, one surface of which is a first surface S1 and the other surface of which is a second surface S2. The first surface S1 may be called an element formation surface or a main surface (front surface), and the second surface S2 may be called a light incidence surface or a back surface. The second surface S2 side of the semiconductor layer 20 has a laminated structure in which a refractive optical element layer 30, a color filter layer 40, and an on-chip lens layer 50 are laminated in that order from the side closer to the second surface S2. Note that, for example, other components may be interposed between each of the components from the semiconductor layer 20 to the on-chip lens layer 50. In the example shown in FIG. 4A, an insulating film m1 is provided between the semiconductor layer 20 and the refractive optical element layer 30, and an insulating film m2 is provided between the refractive optical element layer 30 and the color filter layer 40. In addition, a wiring layer (not shown) is laminated on the first surface S1 side of the semiconductor layer 20. The wiring layer has a multi-layer wiring structure including horizontal wirings that are laminated via an insulating film and extend mainly along the horizontal direction, and vertical wirings that extend mainly along the thickness direction within the insulating film. In this embodiment, the components laminated on the first surface S1 side of the photodetector 1 will not be described.

<Semiconductor Layer>
As shown in Fig. 4A, the semiconductor layer 20 is made of a semiconductor substrate. The semiconductor layer 20 is made of, for example, a single crystal silicon (Si) substrate, but is not limited thereto. In a portion of the semiconductor layer 20 corresponding to the pixel region 2A, a plurality of cell regions 20a are provided in a matrix on a two-dimensional plane including the X direction and the Y direction. The cell region 20a is provided for each pixel 3. For example, an island-shaped cell region 20a partitioned by an isolation region 20b is provided for each pixel 3. The number of pixels 3 is not limited to that shown in Fig. 4A.

The separation region 20b is provided with, for example, a trench structure, but is not limited thereto. More specifically, a groove is formed in the separation region 20b of the semiconductor layer 20 along the thickness direction, and a partition material is embedded in the formed groove to form a partition wall 21 of the trench structure. FIG. 4G is an explanatory diagram of one cell region 20a observed from the second surface S2 side. The partition wall 21 surrounds the cell region 20a in a plan view. FIG. 4A is a cross-sectional view taken along the A-A cutting line in FIG. 4G. As shown in FIG. 4A, the partition wall 21 extends from the first surface S1 to the second surface S2 along the Z direction. Examples of the partition material include silicon oxide (SiO ₂ ), an air gap (air gap), and a high refractive index material. Examples of high refractive index materials include titanium oxide (TiO ₂ ), silicon nitride (Si ₃ N ₄ ), hafnium oxide (HfO ₂ ), and tantalum oxide (Ta ₂ O ₅ ). In this embodiment, an example in which silicon oxide is used as the partition material will be described.

In the cell region 20a, two photoelectric conversion elements, the photoelectric conversion element PD1 (first photoelectric conversion element) and the photoelectric conversion element PD2 (second photoelectric conversion element) shown in FIG. 3, are configured in each cell region 20a. In the cell region 20a, the photoelectric conversion elements PD1 and PD2 are arranged side by side along the first direction (the X direction in this embodiment). For example, in the cell region 20a, the photoelectric conversion element PD1 is arranged on the right side of the paper, and the photoelectric conversion element PD2 is arranged on the left side of the paper. When the photoelectric conversion element PD1 and the photoelectric conversion element PD2 are not distinguished from each other, they are simply called the photoelectric conversion element PD. In addition, elements and diffusion regions other than the photoelectric conversion element PD, such as transistors and charge storage regions FD, may be configured in the cell region 20a, but illustration and description of them are omitted in this embodiment.

In the cell region 20a, a semiconductor region having a different conductivity type from the surrounding area is provided by ion-injecting impurities between the area where the photoelectric conversion element PD1 is configured and the area where the photoelectric conversion element PD2 is configured, thereby dividing the cell region 20a into the semiconductor region 23 and the semiconductor region 24, and electrically isolating the photoelectric conversion element PD1 from the photoelectric conversion element PD2. The semiconductor regions 23 and 24 are sub-cell regions. The impurity partition structure obtained by ion-injecting impurities into the semiconductor layer 20 in this manner is called the partition structure 22, and is represented by the dashed lines shown in Figures 4A and 4G. The partition structure 22 is a centrally separated structure that extends along the Z direction and the Y direction. The photoelectric conversion element PD1 is configured in the semiconductor region 23, and the photoelectric conversion element PD2 is configured in the semiconductor region 24.

<Refractive Optical Element Layer>
1, the refractive optical element layer 30 is provided at a position overlapping the pixel region 2A in plan view. The refractive optical element layer 30 includes a plurality of refractive optical elements 31 arranged in a matrix on a two-dimensional plane including the X direction and the Y direction. The refractive optical element 31 is provided for each pixel 3, that is, for each cell region 20a. More specifically, the refractive optical element 31 is provided at a position overlapping the cell region 20a in plan view.

As shown in FIG. 4A, in the thickness direction, the refractive optical element layer 30 is provided between the light incidence surface (second surface S2) of the semiconductor layer 20 and the color filter layer 40. The refractive optical element 31 has a first portion 32 and a second portion 33. The first portion 32 and the second portion 33 are arranged so as to be adjacent to each other along the X direction, and have different refractive indices. The first portion 32 has a first refractive index n1, and the second portion 33 has a second refractive index n2 higher than the first refractive index n1 (n1<n2). The thickness (dimension along the Z direction) of the refractive optical element 31 is 30 nm or more and 200 nm or less. In this embodiment, the thickness (dimension along the Z direction) of the first portion 32 and the second portion 33 are the same.

The arrangement of the first portion 32 and the second portion 33 will be described below. In the longitudinal cross-sectional view shown in FIG. 4A, the first portion 32 is arranged on the right side (closer to the photoelectric conversion element PD1), and the second portion 33 is arranged on the left side (closer to the photoelectric conversion element PD2). In this embodiment, the arrangement of the first portion 32 and the second portion 33 is the same for one row of the refractive optical elements 31 arranged in a matrix. When light L is incident on the refractive optical element 31 shown in FIG. 4A, the speed at which the incident light travels is slower in the second portion 33, which has a higher refractive index than in the first portion 32. As a result, the wavefront of the light is rotated clockwise around the axis perpendicular to the paper, and the light L is guided toward the photoelectric conversion element PD2, which is on the left side of the photoelectric conversion element PD1 and the photoelectric conversion element PD2. In this way, the refractive optical element 31 shown in FIG. 4A guides (wave-guides) light L to one side along the X direction (the left side of FIG. 4A), and is therefore sometimes referred to as the refractive optical element 31L.

As shown in FIG. 4B, the arrangement of the first portion 32 and the second portion 33 of the other row of refractive optical elements 31 adjacent to the row of refractive optical elements 31 in the Y direction is reversed from that of FIG. 4A. In the row of refractive optical elements 31 shown in FIG. 4B, the first portion 32 is arranged on the left side (closer to the photoelectric conversion element PD2), and the second portion 33 is arranged on the right side (closer to the photoelectric conversion element PD1). In this embodiment, the arrangement of the first portion 32 and the second portion 33 is the same for the row of refractive optical elements 31 of the multiple refractive optical elements 31 arranged in a matrix. When light L is incident on the refractive optical element 31 shown in FIG. 4B, the speed at which the incident light L travels is slower in the second portion 33, which has a higher refractive index than the first portion 32. As a result, the wavefront of the light is rotated counterclockwise around an axis perpendicular to the page, and light L is guided in a direction toward photoelectric conversion element PD1, which is on the right side of photoelectric conversion element PD1 and photoelectric conversion element PD2. In this way, refractive optical element 31 shown in FIG. 4B guides (waveguides) light L to the other side along the X direction (the right side in FIG. 4B), and is therefore sometimes referred to as refractive optical element 31R.

Thus, the refractive optical element layer 30 includes both the refractive optical element 31L and the refractive optical element 31R. When the refractive optical element 31L and the refractive optical element 31R are not distinguished from each other, they are simply referred to as the refractive optical element 31. In this embodiment, an example is described in which the photodetector 1 has the refractive optical element 31L shown in FIG. 4A and the refractive optical element 31R shown in FIG. 4B arranged alternately in rows along the Y direction. In addition, the refractive optical element layer 30, i.e., the refractive optical element 31, is provided as close as possible to the semiconductor layer 20, thereby enhancing the effect of guiding light L to the photoelectric conversion element PD that overlaps with the second portion 33.

Figure 4C is a plan view showing an arrangement of refractive optical elements 31 in two rows and two columns. In one refractive optical element 31, the size of the area occupied by the second part 33 in a plan view is the same as the size of the area occupied by the first part 32. Of the two rows and two columns of refractive optical elements 31, the two on the upper side of the paper are refractive optical elements 31L, and the two on the lower side of the paper are refractive optical elements 31R. The pixel 3 that overlaps the refractive optical element 31L in a plan view is called pixel 3L, and the pixel 3 that overlaps the refractive optical element 31R in a plan view is called pixel 3R, and they are distinguished from each other. When the pixel 3L and the pixel 3R are not distinguished from each other, they are simply called pixel 3. Similarly, the cell region 20a that overlaps the refractive optical element 31L in a plan view is called cell region 20aL, and the cell region 20a that overlaps the refractive optical element 31R in a plan view is called cell region 20aR, and they are distinguished from each other. Cell area 20aL is the cell area for the left side, and cell area 20aR is the cell area for the right side. When there is no need to distinguish between cell area 20aL and cell area 20aR, they are simply referred to as cell area 20a.

Figure 4D is a diagram showing the sensitivity of the photoelectric conversion element PD1 and the photoelectric conversion element PD2 configured in the cell region 20aL for the left side to the incident angle of light. Figure 4E is a diagram showing the sensitivity of the photoelectric conversion element PD1 and the photoelectric conversion element PD2 configured in the cell region 20aR for the right side to the incident angle of light. As shown in Figure 4D, in the cell region 20aL, the separation ratio is improved in the region where the incident angle of light is 0° or less. And, as shown in Figure 4E, in the cell region 20aR, the separation ratio is improved in the region where the incident angle of light is 0° or more. And, by combining and using the region where the incident angle of light is 0° or less in Figure 4D and the region where the incident angle of light is 0° or more in Figure 4E, the separation ratio can be improved in the region from negative incident angles to positive incident angles. That is, by combining the refractive optical element 31L and the refractive optical element 31R, the separation ratio can be improved.

The difference between the first refractive index n1 and the second refractive index n2 is, for example, 0.2 or more and 0.5 or less. Such a difference in refractive index is determined by the combination of the material constituting the first portion 32 and the material constituting the second portion 33. The first portion 32 can be made of a material having a refractive index n of about 1.24, for example. More specifically, the material constituting the first portion 32 can be, for example, filler-filled silica, a resin material with a low refractive index, etc. The second portion 33 can be made of a material having a refractive index n of about 1.9 or more, for example. More specifically, the material constituting the second portion 33 can be, for example, silicon nitride (Si ₃ N ₄ ), titanium oxide (TiO ₂ ), and tantalum oxide (Ta ₂ O ₅ ), etc. In addition, since silicon oxide (SiO ₂ ) has a refractive index n of about 1.4, it can be used as the material constituting the first portion 32 or the second portion 33 depending on the combination with the above-mentioned materials.

<Color filter layer>
As shown in Fig. 4A, the color filter layer 40 has color filters 41 and partition walls 42 that partition the color filters 41 from one another. The color filters 41 are provided for each pixel 3. As shown in Fig. 4F, the color filters 41 include three types of filters: a filter R for red light, a filter G for green light, and a filter B for blue light, and filters of the same color are arranged in two rows and two columns. The two-row and two-column cell regions 20a shown in Fig. 4C all overlap color filters 41 of the same color in a plan view. The color filters 41 are made of, for example, a known resin.

As shown in FIG. 4A, the partition wall 42 is provided to further facilitate focusing of incident light on the pixel 3. A material having a lower refractive index than that of the material of the color filter 41 is used as a material constituting the partition wall 42. This allows the partition wall 42 to guide light, and further facilitates focusing of light that has passed through the on-chip lens layer 50 on the pixel 3. Examples of materials constituting the partition wall 42 include silicon oxide (SiO ₂ ), air, and low refractive index materials. Examples of low refractive index materials include filler-filled silica, known low refractive index resin materials, and the like. In this embodiment, the partition wall 42 is described as being composed of a low refractive index resin material.

<On-chip lens layer>
4A , the on-chip lens layer 50 includes a plurality of microlenses (on-chip lenses) 51 provided for each pixel 3. The on-chip lens layer 50 is made of, for example, a known resin, and the refractive index thereof is, but is not limited to, for example, about 1.5 or more and 1.6 or less.

<Insulating film>
The insulating film m1 and the insulating film m2 are made of known insulating materials. Examples of insulating materials constituting the insulating film m1 include, but are not limited to, tantalum oxide (Ta ₂ O ₅ ), silicon oxide (SiO ₂ ), and aluminum oxide (AlO, Al ₂ O ₃ ). The insulating film m1 may be provided in a multi-layered structure, in which case films made of different materials among the insulating materials mentioned above may be combined. Examples of insulating materials constituting the insulating film m2 include, but are not limited to, silicon oxide (SiO ₂ ).

<<Main Effects of the First Embodiment>>
The main effects of the first embodiment will be described below. In the photodetector 1 according to the first embodiment of the present technology, the refractive optical element 31 has a first portion 32 having a first refractive index n1 and a second portion 33 having a second refractive index n2 higher than the first refractive index n1 along the first direction, so that light incident on the photodetector 1 can be guided to the second portion 33 side of the first portion 32 and the second portion 33 along the first direction. This makes it possible to collect more light toward the photoelectric conversion element located closer to the second portion 33 side in a planar view out of the photoelectric conversion element PD1 and the photoelectric conversion element PD2, and to suppress a decrease in the separation ratio. In particular, even if the effect of light diffraction by the on-chip lens layer 50 becomes insufficient due to further miniaturization of the pixel 3, it is possible to collect more light toward the photoelectric conversion element located closer to the second portion 33 side in a planar view out of the photoelectric conversion element PD1 and the photoelectric conversion element PD2, and to suppress a decrease in the separation ratio.

In the light detection device 1 according to the first embodiment of the present technology, one refractive optical element 31L has a first portion 32 at a position closer to the photoelectric conversion element PD1 along the first direction and a second portion 33 at a position closer to the photoelectric conversion element PD2 along the first direction, and the other refractive optical element 31 has a second portion 33 at a position closer to the photoelectric conversion element PD1 along the first direction and a first portion 32 at a position closer to the photoelectric conversion element PD2 along the first direction. In this way, the refractive optical element 31L designed to collect light toward the photoelectric conversion element PD2 side of the photoelectric conversion element PD1 and the photoelectric conversion element PD2, and the refractive optical element 31R designed to collect light toward the photoelectric conversion element PD1 side are combined to obtain the phase difference between the output of the photoelectric conversion element PD1 and the output of the photoelectric conversion element PD2, so that the phase difference between the output of the photoelectric conversion element PD1 and the output of the photoelectric conversion element PD2 can be obtained in a state in which the reduction in the separation ratio is suppressed. The lens can then be driven based on the phase difference thus determined to achieve focus.

In addition, in the photodetector 1 according to the first embodiment of the present technology, the first direction is the X direction, so the phase difference between the output of the photoelectric conversion element PD1 and the output of the photoelectric conversion element PD2 can be found along the X direction.

<Modification of the First Embodiment>
Modifications of the first embodiment will be described below. Note that in the following modifications, only one of the refractive optical element 31L and the refractive optical element 31R may be shown, and the other refractive optical element may be omitted from the drawings.

<Modification 1>
In the photodetector 1 according to the first embodiment, the first direction is the X direction as shown in Fig. 4C, but the present technology is not limited to this. In the photodetector 1 according to the first modification of the first embodiment, the first direction is the Y direction as shown in Fig. 6.

Figure 6 is a plan view showing an arrangement of refractive optical elements 31 in two rows and two columns. Note that in Figure 6, the positional relationship between the refractive optical element 31 and the photoelectric conversion elements PD1, PD2 is supplemented. Note that in the figures following Figure 6, the positional relationship between the refractive optical element 31 and the photoelectric conversion elements PD1, PD2 may be supplemented in a similar manner. In the cell region 20a, the photoelectric conversion elements PD2, PD1 are arranged side by side along the Y direction. For example, in the cell region 20a, the photoelectric conversion element PD1 is arranged on the upper side of the paper, and the photoelectric conversion element PD2 is arranged on the lower side of the paper.

In the refractive optical element 31, the size of the area occupied by the second portion 33 in a planar view is the same as the size of the area occupied by the first portion 32. Of the two rows and two columns of refractive optical elements 31, the two on the right side of the paper are refractive optical elements 31UP, and the two on the left side of the paper are refractive optical elements 31LO. When the refractive optical elements 31UP and 31LO are not distinguished from each other, they are simply called refractive optical elements 31. In addition, the pixel 3 that overlaps the refractive optical element 31UP in a planar view is called pixel 3UP, and the pixel 3 that overlaps the refractive optical element 31LO in a planar view is called pixel 3LO, and they are distinguished from each other. When the pixel 3UP and the pixel 3LO are not distinguished from each other, they are simply called pixel 3. Similarly, the cell region 20a that overlaps the refractive optical element 31UP in plan view is called the cell region 20aUP, and the cell region 20a that overlaps the refractive optical element 31LO in plan view is called the cell region 20aLO, and they are distinguished from each other. The cell region 20aUP is the upper cell region, and the cell region 20aLO is the lower cell region. When there is no distinction between the cell region 20aUP and the cell region 20aLO, they are simply called the cell region 20a. In addition, the refractive optical element 31UP and the refractive optical element 31LO may be arranged alternately in a row on a two-dimensional plane including the X direction and the Y direction, for example.

The refractive optical element 31UP has a first portion 32 disposed on the lower side (closer to the photoelectric conversion element PD2) and a second portion 33 disposed on the upper side (closer to the photoelectric conversion element PD1). When light is incident on the refractive optical element 31UP, the speed at which the incident light travels is slower in the second portion 33, which has a higher refractive index than in the first portion 32. This allows the light to be guided toward the photoelectric conversion element PD1, one of the photoelectric conversion elements PD1 and PD2.

The refractive optical element 31LO has the second portion 33 disposed on the lower side (closer to the photoelectric conversion element PD2) and the first portion 32 disposed on the upper side (closer to the photoelectric conversion element PD1). When light is incident on the refractive optical element 31LO, the speed at which the incident light travels is slower in the second portion 33, which has a higher refractive index than in the first portion 32. This allows the light to be directed toward the photoelectric conversion element PD2, one of the photoelectric conversion elements PD1 and PD2.

The light detection device 1 according to this modified example 1 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

In addition, in the photodetector 1 according to the first modification of the first embodiment of the present technology, since the first direction is the Y direction, the phase difference between the output of the photoelectric conversion element PD1 and the output of the photoelectric conversion element PD2 can be obtained along the Y direction.

<Modification 2>
In the photodetector 1 according to the first embodiment, the first portion 32 and the second portion 33 are arranged side by side along the X direction as shown in Fig. 4C, and in the photodetector 1 according to the first modification of the first embodiment, the first portion 32 and the second portion 33 are arranged side by side along the Y direction as shown in Fig. 6, but the present technology is not limited to this. The photodetector 1 according to the second modification of the first embodiment has a region where the first portion 32 and the second portion 33 are arranged side by side along the X direction and a region where they are arranged side by side along the Y direction as shown in Fig. 7.

In the example shown in FIG. 7, although not limited thereto, for example, of the refractive optical elements 31 arranged in two rows and two columns, the refractive optical element 31UP is arranged in the upper right, the refractive optical element 31R is arranged in the lower right, the refractive optical element 31L is arranged in the upper left, and the refractive optical element 31LO is arranged in the lower left. In addition, in this modified example, in the cell regions 20aL and 20aR overlapping the refractive optical elements 31L and 31R, the photoelectric conversion elements PD2 and PD1 are arranged side by side along the X direction. In the cell regions 20aUP and 20aLO overlapping the refractive optical elements 31UP and 31LO, the photoelectric conversion elements PD2 and PD1 are arranged side by side along the Y direction. In addition, in this modified example, one of the X direction and the Y direction is the first direction, and the other is the second direction.

The light detection device 1 according to this modified example 2 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to modified example 1 of the first embodiment described above.

In addition, in the photodetector 1 according to the second modification of the first embodiment of the present technology, the phase difference between the output of the photoelectric conversion element PD1 and the output of the photoelectric conversion element PD2 can be obtained along both the X direction and the Y direction.

<Modification 3>
The photodetector 1 according to the third modification of the first embodiment has an area in which refractive optical elements 31L are arranged side by side along both the X direction and the Y direction as shown in FIG. 8A, and an area in which refractive optical elements 31R are arranged side by side along both the X direction and the Y direction as shown in FIG. 8B.

The light detection device 1 according to the third modification of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

<Modification 4>
The photodetector 1 according to the fourth modification of the first embodiment has an area in which refractive optical elements 31UP are arranged side by side along both the X direction and the Y direction as shown in FIG. 9A, and an area in which refractive optical elements 31LO are arranged side by side along both the X direction and the Y direction as shown in FIG. 9B.

The light detection device 1 according to this fourth modification of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to the first modification of the first embodiment described above.

<Modification 5>
The photodetector 1 relating to the fifth variant of the first embodiment has an area in which the refractive optical element 31LO and the refractive optical element 31L are arranged side by side as shown in FIG. 10A, and an area in which the refractive optical element 31UP and the refractive optical element 31R are arranged side by side as shown in FIG. 10B.

The light detection device 1 according to this modified example 5 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment and the light detection device 1 according to modified example 2 of the first embodiment.

<Modification 6>
In the photodetector 1 according to the first embodiment, as shown in Fig. 4C, the size of the area occupied by the second portion 33 in the refractive optical element 31 in a plan view is the same as the size of the area occupied by the first portion 32, but the present technology is not limited to this. In the photodetector 1 according to the sixth modification of the first embodiment, as shown in Fig. 11, the size of the area occupied by the second portion 33 in the refractive optical element 31 in a plan view is set to be different from the size of the area occupied by the first portion 32. More specifically, the size of the area occupied by the second portion 33 is set to be larger than the size of the area occupied by the first portion 32.

In the refractive optical element 31, the second portion 33 is expanded toward the first portion 32 along the first direction (X direction) in a plan view. Therefore, in the refractive optical element 31, the area of the second portion 33 that overlaps with the center of the cell region 20a in a plan view is larger than that of the first portion 32.

The photodetector 1 according to this sixth modification of the first embodiment can achieve the same effects as the photodetector 1 according to the first embodiment described above.

In addition, in the refractive optical element 31 of the light detection device 1 according to the sixth variant of the first embodiment of the present technology, the size of the area occupied by the second portion 33, which has a higher refractive index than the first portion 32, is set to be larger than the size of the area occupied by the first portion 32 in a planar view, so that more light passes through the second portion 33 and can be guided toward the photoelectric conversion element PD that overlaps with the second portion 33 in a planar view.

In addition, in the light detection device 1 according to the sixth modified example of the first embodiment, the second portion 33 is configured so that the area overlapping with the center of the cell region 20a in a planar view is greater than that of the first portion 32. The center of the cell region 20a in a planar view is the light collection point where most light hits. By increasing the area overlapping with such a light collection point in the second portion 33 compared to the first portion 32, more light can be guided toward the photoelectric conversion element PD that overlaps with the second portion 33 in a planar view.

<Modification 7>
In the photodetector 1 according to the first embodiment, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 is linear (straight line) as shown in Fig. 4C, but the present technology is not limited to this. In the photodetector 1 according to the seventh modification of the first embodiment, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 is curved rather than linear as shown in Fig. 12.

In the light detection device 1 according to the seventh modified example of the first embodiment, as shown in FIG. 12, at the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, the center portion of the second portion 33 in the second direction (Y direction) perpendicular to the first direction (X direction) is located closer to the first portion 32 than the end portion in a plan view. More specifically, the center portion of the second portion 33 in the Y direction protrudes toward the first portion 32 in a triangular shape in a plan view. As a result of the center portion of the second portion 33 in the Y direction protruding toward the first portion 32, the second portion 33 in the refractive optical element 31 has a larger area overlapping the center portion of the cell region 20a in a plan view than the first portion 32.

The light detection device 1 according to the seventh modified example of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

In addition, in the photodetector 1 according to the seventh modification of the first embodiment of the present technology, the area where the second portion 33 overlaps with the center of the cell region 20a in a planar view is increased from the first portion 32, so that more light can be guided toward the photoelectric conversion element PD that overlaps with the second portion 33 in a planar view.

<Modification 8>
In the light detection device 1 according to the eighth modified example of the first embodiment, as shown in FIG. 13, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 is curved rather than linear. In addition, in the light detection device 1 according to the eighth modified example of the first embodiment, as shown in FIG. 13, at the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, the center portion of the first portion 32 in the second direction (Y direction) perpendicular to the first direction (X direction) is located closer to the second portion 33 than the end portion in a plan view. More specifically, the center portion of the first portion 32 in the Y direction in a plan view protrudes toward the second portion 33 in a triangular shape. In addition, in this modified example, the size of the area occupied by the second portion 33 is set smaller than the size of the area occupied by the first portion 32. This allows the angle at which light is bent to be adjusted to be smaller.

The light detection device 1 according to this modification 8 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

<Modification 9>
In the photodetector 1 according to the 9th modification of the first embodiment, as shown in FIG. 14, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 is curved rather than linear. In the photodetector 1 according to the 9th modification of the first embodiment, as shown in FIG. 14, at the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, the center portion of the second portion 33 in the second direction (Y direction) perpendicular to the first direction (X direction) is located closer to the first portion 32 than the end portion in a plan view. More specifically, the center portion of the second portion 33 in the Y direction in a plan view forms a trapezoidal shape and protrudes toward the first portion 32. As a result of the center portion of the second portion 33 in the Y direction protruding toward the first portion 32, in the refractive optical element 31, the second portion 33 has a larger area overlapping the center portion of the cell region 20a in a plan view than the first portion 32.

The light detection device 1 according to this modification 9 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

In addition, in the light detection device 1 according to the ninth variant of the first embodiment of the present technology, the area where the second portion 33 overlaps with the center of the cell region 20a in a planar view is increased from the first portion 32, so that more light can be guided toward the photoelectric conversion element PD that overlaps with the second portion 33 in a planar view.

<Modification 10>
In the light detection device 1 according to the modification 10 of the first embodiment, as shown in FIG. 15, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 is curved rather than linear. Also, in the light detection device 1 according to the modification 10 of the first embodiment, as shown in FIG. 15, at the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, the center portion of the first portion 32 in the second direction (Y direction) perpendicular to the first direction (X direction) is located closer to the second portion 33 than the end portion in a plan view. More specifically, the center portion of the first portion 32 in the Y direction in a plan view forms a trapezoidal shape and protrudes toward the second portion 33. Also, in this modification, the size of the area occupied by the second portion 33 is set smaller than the size of the area occupied by the first portion 32. This allows the angle at which light is bent to be adjusted to be smaller.

The light detection device 1 according to this modification 10 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

<Modification 11>
In the photodetector 1 according to the eleventh modification of the first embodiment, as shown in Fig. 16, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 is gradually curved in an arc shape rather than a straight line shape. In the photodetector 1 according to the eleventh modification of the first embodiment, as shown in Fig. 16, at the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, the center portion of the second portion 33 in the second direction (Y direction) perpendicular to the first direction (X direction) is located closer to the first portion 32 than the end portion in a plan view. More specifically, the center portion of the second portion 33 in the Y direction in a plan view forms an elliptical arc shape and protrudes toward the first portion 32. Furthermore, as a result of the central portion of the second portion 33 in the Y direction protruding toward the first portion 32, in the refractive optical element 31, the second portion 33 has a larger area overlapping with the central portion of the cell region 20a in a planar view than the first portion 32.

Even with the light detection device 1 according to this modification 11 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the photodetector 1 according to variant 11 of the first embodiment of the present technology, the area where the second portion 33 overlaps with the center of the cell region 20a in a planar view is increased from the first portion 32, so that more light can be guided toward the photoelectric conversion element PD that overlaps with the second portion 33 in a planar view.

<Modification 12>
In the light detection device 1 according to the modified example 12 of the first embodiment, as shown in FIG. 17, the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 may be gradually curved in an arc shape instead of a straight line. Also, in the light detection device 1 according to the modified example 12 of the first embodiment, as shown in FIG. 17, at the boundary between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, the center portion of the first portion 32 in the second direction (Y direction) perpendicular to the first direction (X direction) is located closer to the second portion 33 side than the end portion in a plan view. More specifically, the center portion of the first portion 32 in the Y direction in a plan view forms an elliptical arc shape and protrudes toward the second portion 33. Also, in this modified example, the size of the area occupied by the second portion 33 is set smaller than the size of the area occupied by the first portion 32. This allows the angle at which light is bent to be adjusted to be smaller.

The light detection device 1 according to this modification 12 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

<Modification 13>
In the photodetector 1 according to the first embodiment, the first portions 32 and the second portions 33 are periodically arranged as shown in, for example, Figures 4A and 4B, but the present technology is not limited to this. In the photodetector 1 according to the modification 13 of the first embodiment, at least two or more patterns of arrangement of the first portions 32 and the second portions 33 shown in, for example, Figures 4C, 6, 7, 8A, 8B, 9A, 9B, 10A, and 10B may be combined.

Even with the light detection device 1 according to this modification 13 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

<Modification 14>
In the photodetector 1 according to the first embodiment, the first portion 32 and the second portion 33 are in contact with each other as shown in Fig. 4A, but the present technology is not limited to this. In the photodetector 1 according to the fourteenth modification of the first embodiment, a gap is provided between the first portion 32 and the second portion 33 as shown in Figs. 18A and 18B.

Depending on the manufacturing method, a gap may occur between the first portion 32 and the second portion 33. The gap is between the first portion 32 and the second portion 33. More specifically, the gap is between the first portion 32 and the second portion 33 belonging to the same refractive optical element 31, and between the refractive optical elements 31. A third portion 34 is provided in the gap, and the first portion 32 and the second portion 33 are separated by the third portion 34. The third refractive index n3, which is the refractive index of the third portion 34, is different from the first refractive index n1 and the second refractive index n2 (n3 ≠ n1, n2). More specifically, the third refractive index n3 is a value larger than the first refractive index n1 and smaller than the second refractive index n2 (n1 < n3 < n2). For example, when the first refractive index n1=1.24 and the second refractive index n2=1.9, silicon oxide (SiO ₂ ) having a third refractive index n3=1.4 can be provided as the third portion 34. The photodetector 1 includes such a third portion 34.

Even with the light detection device 1 according to this modification 14 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to the modification 14 of the first embodiment of the present technology, a third portion 34 having a third refractive index n3, which is a value between the first refractive index n1 and the second refractive index n2, is interposed between the first portion 32 and the second portion 33. Therefore, the refractive index gradually increases from the first portion 32 to the second refractive index n2, so that the rotation of the wavefront of the light incident on the pixel 3 becomes smooth.

The gap between the first portion 32 and the second portion 33 can be designed for reasons other than those related to the manufacturing method. The third portion 34 and the insulating film m2 can be formed separately or together.

<Modification 15>
In the light detection device 1 according to the above-mentioned modified example 14 of the first embodiment, as shown in Figs. 18A and 18B, the third portion 34 is provided between all the first portions 32 and the second portions 33, but the present technology is not limited thereto. In the light detection device 1 according to the modified example 15 of the first embodiment, as shown in Figs. 19A and 19B, the first portions 32 and the second portions 33 belonging to the same refractive optical element 31 are in contact with each other, and the third portions 34 are provided only in the gaps between the refractive optical elements 31. More specifically, the gap is between the first portion 32 of the refractive optical element 31 and the second portion 33 of another refractive optical element 31 adjacent to the refractive optical element 31. If there is another medium between the first portion 32 and the second portion 33, this may cause scattering. Therefore, the first portion 32 and the second portion 33 belonging to the same refractive optical element 31 are provided so as to be in contact with each other.

Even with the light detection device 1 according to this modified example 15 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to variant 15 of the first embodiment of the present technology, the first portion 32 and the second portion 33 are in contact with each other in the refractive optical element 31, so that scattering occurring between the first portion 32 and the second portion 33 can be suppressed.

<Modification 16>
In the photodetector 1 according to the modification 14 of the first embodiment and the photodetector 1 according to the modification 15 of the first embodiment described above, the third portion 34 is made of silicon oxide, but the present technology is not limited to this. In the photodetector 1 according to the modification 16 of the first embodiment, the third portion 34 is made of silicon oxynitride (SiON) or a resin material, as shown in Fig. 20. Note that the plan view of the refractive optical element 31 in this modification is the same as Fig. 18B described above, although the material is different.

Even with the light detection device 1 according to this modification 16 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

<Modification 17>
In the photodetection device 1 according to the first embodiment, as shown in Fig. 4A, the refractive optical element layer 30 is provided between the light incident surface (second surface S2) of the semiconductor layer 20 and the color filter layer 40 in the thickness direction, but the present technology is not limited to this. In the photodetection device 1 according to the seventeenth modification of the first embodiment, as shown in Fig. 21, the refractive optical element layer 30 is disposed at a different position in the optical path of the light incident on the photodetection device 1. More specifically, the refractive optical element layer 30 is provided between the color filter layer 40 and the on-chip lens layer 50 in the thickness direction.

The light detection device 1 according to this modification 17 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above.

<Modification 18>
In the photodetector 1 according to the first embodiment, the first portion 32 and the second portion 33 have a rectangular cross-sectional shape as shown in Fig. 4A, but the present technology is not limited to this. In the photodetector 1 according to the eighteenth modification of the first embodiment, the first portion 32 and the second portion 33 may have a tapered cross-sectional shape as shown in Fig. 22. Note that the second portion 33 has a tapered shape in which the width of the portion closer to the color filter layer 40 is narrower than the width of the portion closer to the semiconductor layer 20.

Even with the light detection device 1 according to this modification 18 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

As shown in FIG. 23, the second portion 33 may have a tapered shape in which the width of the portion closer to the color filter layer 40 is wider than the width of the portion closer to the semiconductor layer 20.

<Modification 19>
In the photodetector 1 according to the modification 19 of the first embodiment, as shown in FIG. 24, an etching stopper layer m3 may be provided on the semiconductor layer 20 side of the refractive optical element layer 30. When forming the refractive optical element layer 30, the etching stopper layer m3 is formed on the exposed surface of the insulating film m1, and a material constituting the first portion 32 is formed on the exposed surface of the etching stopper layer m3. Then, a mask pattern is formed using a known lithography technique. The mask pattern covers the portion forming the first portion 32 in a plan view, and has an opening in the portion forming the second portion 33. Then, using a known etching technique, the portion of the material constituting the first portion 32 that is exposed from the opening of the mask pattern is etched and removed using a selected etchant. As the material constituting the etching stopper layer m3, a material whose etching rate for the selected etchant is lower than the etching rate for the material constituting the first portion 32 is selected. As the material constituting the etching stopper layer m3, for example, silicon nitride (Si ₃ N ₄ ) and hafnium oxide (HfO ₂ ) can be mentioned. Thereafter, the mask pattern is removed. Then, a film of material constituting the second portion 33 is formed so as to fill in the portion from which the material constituting the first portion 32 has been removed. Thereafter, excess portions of the material constituting the second portion 33 are removed by chemical mechanical polishing (CMP) to obtain the refractive optical element layer 30 shown in FIG.

Even with the light detection device 1 according to this modification 19 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the photodetector 1 according to the modification 19 of the first embodiment of the present technology, etching of the material located on the semiconductor layer 20 side of the etching stopper layer m3 can be suppressed.

In this modification, the material constituting the first portion 32 is deposited first, but the material constituting the second portion 33 may be deposited first. In addition, by using the manufacturing method described in this modification, more specifically by performing etching, the tapered first portion 32 and second portion 33 depicted in FIG. 22 and FIG. 23 according to modification 18 can also be obtained.

<Modification 20>
The light detection device 1 according to the modification 20 of the first embodiment may have anti-reflection films m4 and m5 as shown in FIG. 25. The anti-reflection film m4 is provided on the surface of the refractive optical element layer 30 on the insulating film m1 side, and the anti-reflection film m5 is provided on the surface of the refractive optical element layer 30 on the color filter layer 40 side. If a material with a high refractive index is present, the light may be reflected and travel in the opposite direction as reflected light, which may cause flare. Therefore, the anti-reflection films m4 and m5 are provided to cancel the reflected light. The material constituting the anti-reflection films m4 and m5 may be a known material and may be selected based on the reflection design.

Even with the light detection device 1 according to this modification 20 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

Furthermore, in the light detection device 1 according to the modification 20 of the first embodiment of the present technology, flare can be suppressed. Note that the anti-reflection film may be configured to include only one of the anti-reflection films m4 and m5.

<Modification 21>
In the photodetector 1 according to the first embodiment, the first portion 32 and the second portion 33 have the same thickness as shown in Fig. 4A, but the present technology is not limited to this. In the photodetector 1 according to the twenty-first modification of the first embodiment, the first portion 32 and the second portion 33 may have different thicknesses as shown in Figs. 26A and 26B. In Fig. 26A, the thickness of the first portion 32 is greater than the thickness of the second portion 33. In Fig. 26B, the thickness of the second portion 33 is greater than the thickness of the first portion 32.

For example, when the first portion 32 and the second portion 33 are formed separately using a known etching technique, a step may occur between the first portion 32 and the second portion 33 in the thickness direction, as shown in FIG. 26A. Also, as shown in FIG. 26B, by intentionally making the thickness of the second portion 33 large, the optical path of the light passing through the second portion 33 becomes longer, and more light can be guided toward the photoelectric conversion element PD that overlaps with the second portion 33 in a planar view. Conversely, by intentionally making the thickness of the second portion 33 small, the angle at which the light is bent can be reduced.

Even with the light detection device 1 according to this modification 21 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to the modification 21 of the first embodiment of the present technology, the thicknesses of the first portion 32 and the second portion 33 are made different, which allows various designs of the bending angle of light.

<Modification 22>
27A and 27B, in the photodetector 1 according to the modification 22 of the first embodiment, in a plan view, the size of the area occupied by the second portion 33 and the size of the area occupied by the first portion 32 in the refractive optical element 31 are made to differ depending on the image height position of the refractive optical element 31 in the pixel region 2A (see FIG. 1). Note that the center of the pixel region 2A is the image height center, and the image height increases from the image height center toward the edge of the pixel region 2A.

27A and 27B show a refractive optical element 31 arranged near the image height center, a refractive optical element 31 arranged near the medium image height position, and a refractive optical element 31 arranged near the high image height position. The medium image height position indicates an image height position between the image height center and the high image height position. Near the image height center, the size of the area occupied by the second part 33 in the refractive optical element 31 in a plan view is the same as the size of the area occupied by the first part 32. As shown by the arrow in FIG. 27A, at positions where the image height is high, more light is incident obliquely compared to near the image height center. Therefore, in the light detection device 1 according to this modified example, the higher the image height, the larger the size of the area occupied by the second part 33 in the refractive optical element 31 in a plan view is made larger than the size of the area occupied by the first part 32. This makes it possible to guide more light toward the photoelectric conversion element PD that overlaps with the second portion 33 in a plan view, even at positions with high image heights where there is a lot of obliquely incident light, and thus makes it possible to prevent the separation ratio from changing significantly depending on the image height position.

Even with the light detection device 1 according to this modification 22 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to the modified example 22 of the first embodiment of the present technology, the refractive optical element 31 is configured according to the image height position, so that the separation ratio can be prevented from changing significantly depending on the image height position.

<Modification 23>
In the photodetector 1 according to the first embodiment, as shown in Fig. 4G, the partition structure 22 is an impurity partition structure obtained by ion-implanting impurities, but the present technology is not limited to this. In a modification 23 of the first embodiment, as shown in Fig. 28, instead of the partition structure 22, a partition wall 25a, a partition structure 22, and a partition wall 25b are provided in this order along the Y direction in a plan view as a central separation structure, thereby partitioning the cell region 20a into a semiconductor region 23 and a semiconductor region 24.

The partition walls 25a and 25b are trench structures in which a groove is formed in the thickness direction of the semiconductor layer 20 and a partition material is embedded in the formed groove. The partition walls 25a and 25b are disposed in positions facing each other in a plan view, and one end of each is connected to the partition wall 21. In addition, the partition structure 22 is provided between the partition walls 25a and 25b in a plan view.

The partition walls 25a and 25b are made of the same partition material as the partition wall 21. For example, the partition walls 21, 25a, and 25b are made of silicon oxide (SiO ₂ ) or an air gap (air wall). Also, for example, the partition walls 21, 25a, and 25b may be made of the above-mentioned high refractive index material.

The partition walls 25a and 25b may be made of a different material from that of the partition wall 21. For example, the partition wall 21 may be made of silicon oxide (SiO ₂ ) or an air gap (air wall), and the partition walls 25a and 25b may be made of the above-mentioned high refractive index material.

Even with the light detection device 1 according to this modification 23 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In the photodetector 1 according to the modification 23 of the first embodiment of the present technology, the partition wall 21 is made of silicon oxide (SiO ₂ ) or an air gap (empty wall), and the partition walls 25a and 25b are made of a highly refractive material. Since the partition walls 25a and 25b are made of a highly refractive material, it is possible to suppress the refractive index difference with silicon from increasing, and it is possible to suppress the light irradiated to the center of the cell region 20a from being significantly scattered by the partition walls 25a and 25b. Since it is possible to suppress significant scattering by the partition walls 25a and 25b, and the partition wall 21 is made of silicon oxide (SiO ₂ ) or an air gap (empty wall), it is possible to suppress color mixing with adjacent pixels, more specifically, color mixing with pixels for different colors.

<Modification 24>
In the photodetector 1 according to the first embodiment, as shown in Fig. 4A, the partition wall 21 extends from the first surface S1 to the second surface S2 along the Z direction, but the present technology is not limited to this. In the photodetector 1 according to the modified example 24 of the first embodiment, as shown in Fig. 29, the partition wall 21 does not reach the first surface S1, and a partition structure 26 is provided between the end of the partition wall 21 on the first surface S1 side and the first surface S1. The partition structure 26 is an impurity partition structure obtained by ion-implanting an impurity into the semiconductor layer 20.

The view of one cell region 20a observed from the second surface S2 side may be the same as FIG. 4G. The view of one cell region 20a observed from the second surface S2 side may be the same as FIG. 28, in which case the light detection device 1 has partition wall 25a, partition structure 22, and partition wall 25b in that order along the Y direction in a plan view. The partition material constituting partition walls 21, 25a, and 25b is as described in modification 23 of the first embodiment.

The light detection device 1 according to this modification 24 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to modification 23 of the first embodiment described above.

<Modification 25>
In the photodetector 1 according to the first embodiment, as shown in FIG. 4A, the photoelectric conversion element PD1 and the photoelectric conversion element PD2 are partitioned by the partition structure 22, which is an impurity partition structure, but the present technology is not limited to this. In the photodetector 1 according to the modification 25 of the first embodiment, as shown in FIG. 30, the photoelectric conversion element PD1 and the photoelectric conversion element PD2 are partitioned by a partition wall 25c, which is a trench structure. The partition wall 25c, which is a central separation structure, includes a trench structure in which a groove is formed in the thickness direction of the semiconductor layer 20 and a partition material is embedded in the formed groove. In the vertical cross-sectional view shown in FIG. 30, the partition wall 25c extends from the first surface S1 to the second surface S2 along the Z direction.

The partition wall 25c is made of the same partition material as the partition wall 21. For example, the partition walls 21 and 25c are made of silicon oxide (SiO ₂ ) or an air gap (air wall). Also, for example, the partition walls 21 and 25c may be made of the above-mentioned high refractive index material.

Moreover, the partition wall 25c may be made of a different material from that of the partition wall 21. For example, the partition wall 21 may be made of silicon oxide (SiO ₂ ) or an air gap (air wall), and the partition wall 25c may be made of the above-mentioned high refractive index material.

The light detection device 1 according to this modification 24 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to modification 23 of the first embodiment described above.

<Modification 26>
In this modification, the central separation structure of the light-detecting device 1 according to the modification 25 of the first embodiment will be described in more detail. In the light-detecting device 1 according to the modification 26 of the first embodiment, as shown in FIG. 31, the light-detecting device 1 has a partition structure 22, a partition wall 25c, and a partition structure 22 in that order along the Y direction in a plan view as a central separation structure. That is, as shown in FIG. 31, the partition wall 25c is provided only in the center along the Y direction in a plan view. The partition material constituting the partition walls 21 and 25c is as described in the modification 25 of the first embodiment. FIG. 30 according to the modification 25 corresponds to a cross-sectional view taken along the A-A cutting line in FIG. 31 according to this modification.

The light detection device 1 according to this modification 26 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to modification 25 of the first embodiment described above.

<Modification 27>
In this modification, the central separation structure of the light-detecting device 1 according to the modification 25 of the first embodiment will be described in more detail. In the light-detecting device 1 according to the modification 27 of the first embodiment, as shown in FIG. 32, the light-detecting device 1 has a partition wall 25c and a partition structure 22 along the Y direction in a plan view as a central separation structure. One end of the partition wall 25c along the Y direction in a plan view is connected to the partition wall 21. The partition material constituting the partition walls 21 and 25c is as described in the modification 25 of the first embodiment. FIG. 30 according to the modification 25 corresponds to a cross-sectional view taken along the A-A cutting line in FIG. 32 according to this modification.

The photodetector 1 according to this modification 27 of the first embodiment can achieve the same effects as the photodetector 1 according to the first embodiment described above and the photodetector 1 according to modification 25 of the first embodiment described above.

<Modification 28>
In the photodetector 1 according to the modified example 25 of the first embodiment, as shown in FIG. 30, the partition walls 21 and 25c extend from the first surface S1 to the second surface S2 along the Z direction, but the present technology is not limited thereto. In the photodetector 1 according to the modified example 28 of the first embodiment, as shown in FIG. 33A, the partition walls 21 and 25c do not reach the first surface S1. A partition structure 26 is provided between the end of the partition wall 21 on the first surface S1 side and the first surface S1. A partition structure 22 is provided between the end of the partition wall 25c on the first surface S1 side and the first surface S1. When one cell region 20a is observed from the second surface S2 side, the partition wall 25c extends along the Y direction and is connected to the mutually opposing portions of the partition wall 21 as shown in FIG. 33B. In addition, the view of one cell region 20a observed from the second surface S2 side may be the same as either FIG. 31 or FIG. 32. The partitioning material constituting the partition walls 21 and 25c is as described in the modified example 25 of the first embodiment. Note that Fig. 33A corresponds to a cross-sectional view taken along the line A-A in Figs. 33B, 31, and 32.

The light detection device 1 according to this modification 28 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to modification 25 of the first embodiment described above.

<Modification 29>
In the photodetector 1 according to the modified example 25 of the first embodiment, as shown in FIG. 30, the partition walls 21 and 25c extend from the first surface S1 to the second surface S2 along the Z direction, but the present technology is not limited thereto. In the photodetector 1 according to the modified example 29 of the first embodiment, as shown in FIG. 34, among the partition wall 21 and the partition wall 25c, the partition wall 21 extends from the first surface S1 to the second surface S2, but the partition wall 25c does not reach the first surface S1. A partition structure 22 is provided between the end of the partition wall 25c on the first surface S1 side and the first surface S1. Note that the view of one cell region 20a observed from the second surface S2 side is the same as any one of FIG. 33B, FIG. 31, and FIG. 32. In addition, the partition material constituting the partition walls 21 and 25c is as described in the modified example 25 of the first embodiment. 34 corresponds to a cross-sectional view taken along the line AA in FIG. 33B, FIG. 31, and FIG.

The light detection device 1 according to this modification 29 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment described above and the light detection device 1 according to modification 25 of the first embodiment described above.

<Modification 30>
In the photodetector 1 according to the modification 30 of the first embodiment, a conductive material may be used as the partitioning material of the partition wall 21. A conductive material may also be used as the partitioning material of the partition walls 25a, 25b, and 25c. More specifically, a metal material, a semiconductor material, a transparent conductor, or the like may be used as the partitioning material. When a conductive material is used as the partitioning material of the trench structure, an insulating film is provided between the conductive material and the semiconductor layer 20 to insulate the conductive material. For example, titanium nitride (TiN) may be used as the metal material. For example, polysilicon may be used as the semiconductor material. For example, indium tin oxide (ITO), indium oxide (InO), or the like may be used as the transparent conductor.

Even with the light detection device 1 according to this modification 30 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the photodetector 1 according to variant 30 of the first embodiment of the present technology, pinning can be strengthened by applying a bias voltage to the partition wall 21.

<Modification 31>
35, the photodetector 1 according to the modification 31 of the first embodiment may have a protective film m6 laminated on the surface of the color filter layer 40 on the on-chip lens layer 50 side. The protective film m6 may be required in the manufacturing method, for example, when forming the partition wall 42 of the color filter layer 40. The protective film m6 is provided to suppress the intrusion of moisture and the like into the color filter layer 40, thereby improving reliability. Examples of materials constituting the protective film m6 include silicon oxynitride (SiON), silicon oxide (SiO ₂ ), and aluminum oxide (Al ₂ O ₃ ).

Even with the light detection device 1 according to this modification 31 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

<Modification 32>
36 , in the photodetector 1 according to the modification 32 of the first embodiment, the dimension of the partition wall 42 in the Z direction is smaller than the dimension of the color filter 41 in the Z direction. More specifically, the surface of the partition wall 42 on the on-chip lens layer 50 side is recessed toward the semiconductor layer 20 side from the surface of the color filter 41 on the on-chip lens layer 50 side. The same material as that constituting the microlens 51 is embedded in the region 43 formed between the color filters 41 by the recession of the surface of the partition wall 42 on the on-chip lens layer 50 side.

Even with the light detection device 1 according to this modification 32 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, the optical detection device 1 according to variant 32 of the first embodiment of the present technology can reduce the constraints on the manufacturing method.

<Modification 33>
37, in the photodetector 1 according to the modification 33 of the first embodiment, the partition walls 42 extend into the refractive optical element layer 30. More specifically, the partition walls 42 penetrate the refractive optical element layer 30. As in the above-described modification 32, the surface of the partition wall 42 on the on-chip lens layer 50 side is recessed toward the semiconductor layer 20 side from the surface of the color filter 41 on the on-chip lens layer 50 side. The same material as that constituting the microlenses 51 is embedded in the region 43 formed between the color filters 41 by the recession of the surface of the partition wall 42 on the on-chip lens layer 50 side.

Even with the light detection device 1 according to this modification 33 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to variant 33 of the first embodiment of the present technology, the partition wall 42 made of a material with a low refractive index extends into the refractive optical element layer 30, so that light can be focused even at a position closer to the semiconductor layer 20 along the Z direction, thereby enhancing the waveguiding effect.

<Modification 34>
In the photodetector 1 according to the modification 34 of the first embodiment, as shown in Figs. 38A and 38B, a light-shielding portion 60 is provided in the gap between the color filters 41 on the semiconductor layer 20 side, that is, between the partition wall 42 and the insulating film m1. Fig. 38B is a partial enlarged view of Fig. 38A. As shown in Fig. 38B, the light-shielding portion 60 may include a plurality of layers of light-shielding material. In the example shown in Fig. 38B, the light-shielding portion 60 has a three-layer structure including a first layer 61 made of titanium nitride (TiN), a second layer 62 made of titanium (Ti), and a third layer 63 made of tungsten (W).

Even with the light detection device 1 according to this modification 34 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to the modification 34 of the first embodiment of the present technology, the light shielding portion 60 is provided, so that it is possible to prevent light from being incident on an adjacent color filter between the color filters 41. For example, it is possible to prevent light from being incident on the red color filter 41 from the green color filter 41.

<Modification 35>
39 , in the photodetector 1 according to the modification 35 of the first embodiment, the light-shielding portion 60 is embedded in the semiconductor layer 20. More specifically, at least a part of the light-shielding portion 60 is embedded in the semiconductor layer 20 between the pixels 3 (separation region 20b). The configuration of the light-shielding portion 60 is as described in the above modification 34.

Even with the light detection device 1 according to this modification 35 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to variant example 35 of the first embodiment of the present technology, the light shielding portion 60 is embedded in the semiconductor layer 20, so that stray light can be blocked even if a material with a high refractive index such as the second portion 33 is provided.

<Modification 36>
The photodetector 1 according to the modification 36 of the first embodiment is a combination of the modification 33 and the modification 35 of the first embodiment. In the photodetector 1 according to the modification 36 of the first embodiment, as shown in FIG. 40, the partition wall 42 is extended into the refractive optical element layer 30. More specifically, the partition wall 42 penetrates the refractive optical element layer 30. The surface of the partition wall 42 on the on-chip lens layer 50 side is recessed toward the semiconductor layer 20 side from the surface of the color filter 41 on the on-chip lens layer 50 side. The same material as that constituting the microlens 51 is embedded in the region 43 formed between the color filters 41 by recessing the surface of the partition wall 42 on the on-chip lens layer 50 side. At least a part of the light shielding portion 60 is embedded in the semiconductor layer 20 between the pixels 3 (separation region 20b). The configuration of the light shielding portion 60 is as described in the modification 34 above.

Even with the light detection device 1 according to this modified example 36 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above, the light detection device 1 according to modified example 33 of the first embodiment described above, and the light detection device 1 according to modified example 35 of the first embodiment described above can be obtained.

<Modification 37>
41 , in the photodetector 1 according to the modification 37 of the first embodiment, the light-shielding portion 60 is provided alongside the refractive optical elements 31 along the horizontal direction. More specifically, the light-shielding portion 60 is provided between the refractive optical elements 31.

Even with the light detection device 1 according to this modification 37 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, the light detection device 1 according to variant 37 of the first embodiment of the present technology can block stray light and suppress color mixing.

<Modification 38>
In the photodetector 1 according to the first embodiment, the on-chip lens layer 50 shown in FIG. 4A is made of a material having a refractive index n of, for example, 1.5 or more and 1.6 or less (1.5≦n≦1.6), but the present technology is not limited to this. In the photodetector 1 according to the modification 38 of the first embodiment, the on-chip lens layer 50 shown in FIG. 4A is made of a material having a higher refractive index. The on-chip lens layer 50 of this modification may be made of a material having a refractive index n of, for example, 1.7 or more and 2.0 or less (1.7≦n≦2.0). Examples of materials having a high refractive index include silicon nitride (Si ₃ N ₄ ) and high refractive index resin materials.

Even with the light detection device 1 according to this modification 38 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the photodetector 1 according to variant example 38 of the first embodiment of the present technology, the refractive index of the on-chip lens layer 50 is increased, so that the light-gathering ability of the microlenses 51 can be improved and the size of the focused spot can be prevented from becoming large.

<Modification 39>
42, the photodetector 1 according to the modification 39 of the first embodiment has a metasurface optical element 70 instead of the on-chip lens layer 50. The metasurface optical element 70 has a plurality of structures 71 arranged at intervals in the width direction in a plan view. The thickness and arrangement pitch of the structures 71 are designed for each color of the color filter 41. Examples of materials constituting the structures 71 include silicon nitride (Si ₃ N ₄ ), titanium oxide (TiO ₂ ), tantalum oxide (Ta ₂ O ₅ ), and aluminum oxide (Al ₂ O ₃ ).

Even with the light detection device 1 according to this modification 39 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the light detection device 1 according to variant example 39 of the first embodiment of the present technology, a metasurface optical element 70 is provided instead of a lens, making it possible to collect light from a wider range.

<Modification 40>
In the photodetector 1 according to the modification 40 of the first embodiment, a red light filter R, a green light filter G, and a blue light filter B are arranged in a Bayer array as shown in Fig. 43. Even in the photodetector 1 according to the modification 40 of the first embodiment, the same effects as those of the photodetector 1 according to the above-described first embodiment can be obtained.

<Modification 41>
44, in the photodetector 1 according to the modification 41 of the first embodiment, for each of the filters R, G, and B, filters of the same color are arranged in a row and column for each of the pixels 3. Even in the photodetector 1 according to the modification 41 of the first embodiment, the same effect as that of the photodetector 1 according to the above-described first embodiment can be obtained.

<Modification 42>
45, in the photodetector 1 according to the modification 42 of the first embodiment, for each of the filters R, G, and B, filters of the same color are arranged in a row and four columns of pixels 3. Even in the photodetector 1 according to the modification 42 of the first embodiment, the same effect as that of the photodetector 1 according to the above-described first embodiment can be obtained.

<Modification 43>
In the photodetector 1 according to the modification 43 of the first embodiment, as shown in Fig. 46, the color filter 41 includes a filter R for red light, a filter G for green light, a filter B for blue light, and a filter W for white light. Note that the microlens 51 is not shown in Fig. 46. The photodetector 1 according to the modification 43 of the first embodiment can also provide the same effects as the photodetector 1 according to the above-described first embodiment.

<Modification 44>
In the photodetector 1 according to the modification 44 of the first embodiment, as shown in Fig. 47, the color filter 41 has three types of complementary color filters C, M, and Y instead of filters R, G, and B. Filter C is a filter for cyan, filter M is a filter for magenta, and filter Y is a filter for yellow. Note that the microlenses 51 are not shown in Fig. 47. Even with the photodetector 1 according to the modification 44 of the first embodiment, the same effects as those of the photodetector 1 according to the above-described first embodiment can be obtained.

<Modification 45>
In the photodetector 1 according to the modification 45 of the first embodiment, as shown in Fig. 48, the color filter 41 has four types: a filter G for green light and filters C, M, and Y for complementary colors. Note that the microlenses 51 are not shown in Fig. 48. Even with the photodetector 1 according to the modification 45 of the first embodiment, the same effects as those of the photodetector 1 according to the above-described first embodiment can be obtained.

<Modification 46>
In the photodetector 1 according to the modification 46 of the first embodiment, as shown in Fig. 49, the color filter 41 has six types of filters: R, G, and B, and complementary color filters C, M, and Y. Note that the microlenses 51 are not shown in Fig. 49. Even with the photodetector 1 according to the modification 46 of the first embodiment, the same effects as those of the photodetector 1 according to the above-described first embodiment can be obtained.

<Modification 47>
In the photodetector 1 according to the modification 47 of the first embodiment, as shown in Fig. 50, the color filter 41 has six types of filters: R, G, and B, and complementary color filters C, M, and Y. The arrangement of these filters is different from that shown in Fig. 49 of the modification 46. Note that the microlenses 51 are not shown in Fig. 50. The photodetector 1 according to the modification 47 of the first embodiment can also obtain the same effects as the photodetector 1 according to the above-described first embodiment.

<Modification 48>
In the photodetector 1 according to the first embodiment, as shown in Fig. 4A, one pixel 3 (cell region 20a) is divided into two sub-cell regions, and photoelectric conversion elements PD1 and PD2 and a first portion 32 and a second portion 33 of a refractive optical element 31 are provided for each pixel 3, but the present technology is not limited to this. In the photodetector 1 according to Modification 48 of the first embodiment, as shown in Figs. 51A and 51B, the pixel 3 is not divided, and the photoelectric conversion element PD1 and the photoelectric conversion element PD2 are configured in separate pixels 3 (cell regions 20a), and the first portion 32 and the second portion 33 are provided for the separate pixels 3 (cell regions 20a).

Figure 51C shows the pixels 3 of 4 rows and 4 columns according to this modified example. As shown in Figure 51C, one microlens 51 and one color filter 41 are provided for each pixel 3 of 2 rows and 2 columns. Light transmitted through the same color filter 41 is incident on the pixels 3 of 2 rows and 2 columns that overlap the microlens 51. In this modified example, a filter R for red light, a filter G for green light, and a filter B for blue light are arranged as shown in the figure. The color filters 41 are arranged in different colors for each of the four pixels 3 of 2 rows and 2 columns. As shown in Figure 51B, the pixels 3 of 2 rows and 2 columns that overlap the microlens 51 include two pixels 3L (cell regions 20aL) and two pixels 3R (cell regions 20aR). In a plan view, the first portion 32 overlaps one of the two cell regions 20aL (the cell region on the right side of the paper), and the second portion 33 overlaps the other (the cell region on the left side of the paper). Similarly, in a plan view, one of the two cell regions 20aR (the cell region on the left side of the page) is overlapped by the first portion 32, and the other (the cell region on the right side of the page) is overlapped by the second portion 33. Therefore, the two cell regions 20aL of this modified example form a pair and function in the same way as one cell region 20aL of the first embodiment. And, the two cell regions 20aR of this modified example form a pair and function in the same way as one cell region 20aR of the first embodiment.

Even with the light detection device 1 according to this modification 48 of the first embodiment, the same effects as those of the light detection device 1 according to the first embodiment described above can be obtained.

In addition, in the photodetector 1 according to variant 48 of the first embodiment of the present technology, since there is no need to divide one pixel 3 (cell region 20a) into two sub-cell regions, a phase difference pixel can be configured even if the pixel 3 is further miniaturized.

<Modification 49>
In the photodetector 1 according to the modification 48 of the first embodiment, the color filters 41 are arranged as shown in Fig. 51C, but the present technology is not limited to this. In the photodetector 1 according to the modification 49 of the first embodiment, the filters of the same color may be arranged in two rows and two columns as shown in Fig. 52.

The light detection device 1 according to this modification 49 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment and the light detection device 1 according to modification 48 of the first embodiment.

<Modification 50>
In the modified example 48 of the photodetection device 1 according to the first embodiment, as shown in Fig. 51C, one microlens 51 and one color filter 41 are provided for each pixel 3 in two rows and two columns, but the present technology is not limited to this. In the photodetection device 1 according to the modified example 50 of the first embodiment, as shown in Fig. 53, one microlens 51 and one color filter 41 are provided for each pixel 3 in one row and two columns. Light transmitted through the same color filter 41 is incident on the pixel 3 in the first row and second column that overlaps the microlens 51. Note that Fig. 53 illustrates only one arrangement of the color filter 41, and the arrangements of the other color filters 41 are not illustrated.

The light detection device 1 according to this modification 50 of the first embodiment can achieve the same effects as the light detection device 1 according to the first embodiment and the light detection device 1 according to modification 48 of the first embodiment.

[Second embodiment]
<1. Application examples to electronic devices>
FIG. 54 is a block diagram showing an example configuration of an electronic device having a solid-state imaging device to which the technology of the present disclosure is applied.

The electronic device 1000 is, for example, an imaging device such as a digital still camera or video camera, or an electronic device with an imaging function such as a mobile terminal device such as a smartphone or tablet terminal.

The electronic device 1000 is composed of an optical system (optical lens) 1011, an imaging unit 1012, a signal processing unit 1013, a control unit 1014, a display unit 1015, a recording unit 1016, an operation unit 1017, a communication unit 1018, a power supply unit 1019, and a drive unit 1020. In the electronic device 1000, the signal processing unit 1013, the control unit 1014, the display unit 1015, the recording unit 1016, the operation unit 1017, the communication unit 1018, and the power supply unit 1019 are connected to each other via a bus 1021.

The optical system 1011 is composed of a zoom lens, a focus lens, etc., and collects light 1022 from the subject. The light collected by the optical system 1011 (subject light) is incident on the imaging unit 1012.

The imaging unit 1012 is configured to include a solid-state imaging device such as an image sensor (the above-mentioned light detection device 1) to which the technology disclosed herein is applied. The image sensor as the imaging unit 1012 photoelectrically converts light (subject light) received via the optical system 1011 into an electrical signal, and supplies the resulting signal to the signal processing unit 1013.

The pixel array of this image sensor is provided with phase difference pixels that are regularly arranged in a predetermined array pattern. The phase difference pixels according to the present technology are pixels that can generate signals for detecting phase differences and generate signals for generating captured images according to subject light.

The signal processing unit 1013 is a signal processing circuit that processes the signal supplied from the imaging unit 1012. For example, the signal processing unit 1013 is configured as a DSP (Digital Signal Processor) circuit, etc.

The signal processing unit 1013 processes the signal from the imaging unit 1012 to generate image data of a still image or a video, and supplies the image data to the display unit 1015 or the recording unit 1016. The signal processing unit 1013 also generates data for detecting a phase difference (phase difference detection data) based on the signal from the imaging unit 1012 (phase difference pixels of the image sensor), and supplies the data to the control unit 1014.

The control unit 1014 is configured, for example, as a CPU (Central Processing Unit) or a microprocessor. The control unit 1014 controls the operation of each part of the electronic device 1000.

The display unit 1015 is configured as a display device such as a liquid crystal panel or an organic EL (Electro Luminescence) panel. The display unit 1015 processes image data supplied from the signal processing unit 1013 and displays a still image or a video captured by the imaging unit 1012.

The recording unit 1016 is configured as a recording medium such as a semiconductor memory or a hard disk. The recording unit 1016 records image data supplied from the signal processing unit 1013. The recording unit 1016 also provides the recorded image data under control of the control unit 1014.

The operation unit 1017 is configured as a touch panel in combination with the display unit 1015, in addition to physical buttons, for example. The operation unit 1017 outputs operation commands for various functions of the electronic device 1000 in response to operations by the user. The control unit 1014 controls the operation of each unit based on the operation commands supplied from the operation unit 1017.

The communication unit 1018 is configured, for example, as a communication interface circuit. The communication unit 1018 exchanges data with an external device via wireless or wired communication in accordance with a specific communication standard.

The power supply unit 1019 appropriately supplies various types of power to the signal processing unit 1013, control unit 1014, display unit 1015, recording unit 1016, operation unit 1017, and communication unit 1018 to these devices.

The control unit 1014 also detects the phase difference between the two images based on the phase difference detection data supplied from the signal processing unit 1013. Then, based on the phase difference detection result, the control unit 1014 determines whether the object to be focused on (focus target) is in focus. If the focus target is not in focus, the control unit 1014 calculates the amount of focus deviation (defocus amount) and supplies it to the drive unit 1020.

The drive unit 1020 is composed of, for example, a motor, an actuator, etc., and drives the optical system 1011, which is composed of a zoom lens, a focus lens, etc.

The driving unit 1020 calculates the driving amount of the focus lens of the optical system 1011 based on the defocus amount supplied from the control unit 1014, and moves the focus lens according to the driving amount. When the focus is on the object to be focused, the driving unit 1020 maintains the current position of the focus lens. The electronic device 1000 is configured as described above.

As described above, the present technology is applied to the imaging unit 1012 such as an image sensor. Specifically, the light detection device 1 according to the first embodiment and its modified example can be applied to the imaging unit 1012. By applying the present technology to the imaging unit 1012 such as an image sensor, even if the pixels are miniaturized, it is possible to suppress a decrease in the separation ratio of the phase difference pixels and suppress a decrease in the autofocus performance.

2. Examples of applications to moving objects
The technology according to the present disclosure (the present technology) can be applied to various products. For example, the technology according to the present disclosure may be realized as a device mounted on any type of moving body such as an automobile, an electric vehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personal mobility device, an airplane, a drone, a ship, or a robot.

Figure 55 is a block diagram showing a schematic configuration example of a vehicle control system, which is an example of a mobile object control system to which the technology disclosed herein can be applied.

The vehicle control system 12000 includes a plurality of electronic control units connected via a communication network 12001. In the example shown in FIG. 55, the vehicle control system 12000 includes a drive system control unit 12010, a body system control unit 12020, an outside vehicle information detection unit 12030, an inside vehicle information detection unit 12040, and an integrated control unit 12050. In addition, the functional configuration of the integrated control unit 12050 includes a microcomputer 12051, an audio/video output unit 12052, and an in-vehicle network I/F (interface) 12053.

The drive system control unit 12010 controls the operation of devices related to the drive system of the vehicle according to various programs. For example, the drive system control unit 12010 functions as a control device for a drive force generating device for generating a drive force for the vehicle, such as an internal combustion engine or a drive motor, a drive force transmission mechanism for transmitting the drive force to the wheels, a steering mechanism for adjusting the steering angle of the vehicle, and a braking device for generating a braking force for the vehicle.

The body system control unit 12020 controls the operation of various devices installed in the vehicle body according to various programs. For example, the body system control unit 12020 functions as a control device for a keyless entry system, a smart key system, a power window device, or various lamps such as headlamps, tail lamps, brake lamps, turn signals, and fog lamps. In this case, radio waves or signals from various switches transmitted from a portable device that replaces a key can be input to the body system control unit 12020. The body system control unit 12020 accepts the input of these radio waves or signals and controls the vehicle's door lock device, power window device, lamps, etc.

The outside-vehicle information detection unit 12030 detects information outside the vehicle equipped with the vehicle control system 12000. For example, the image capturing unit 12031 is connected to the outside-vehicle information detection unit 12030. The outside-vehicle information detection unit 12030 causes the image capturing unit 12031 to capture images outside the vehicle and receives the captured images. The outside-vehicle information detection unit 12030 may perform object detection processing or distance detection processing for people, cars, obstacles, signs, or characters on the road surface based on the received images.

The imaging unit 12031 is an optical sensor that receives light and outputs an electrical signal according to the amount of light received. The imaging unit 12031 can output the electrical signal as an image, or as distance measurement information. The light received by the imaging unit 12031 may be visible light, or may be invisible light such as infrared light.

The in-vehicle information detection unit 12040 detects information inside the vehicle. For example, a driver state detection unit 12041 that detects the state of the driver is connected to the in-vehicle information detection unit 12040. The driver state detection unit 12041 includes, for example, a camera that captures an image of the driver, and the in-vehicle information detection unit 12040 may calculate the driver's degree of fatigue or concentration based on the detection information input from the driver state detection unit 12041, or may determine whether the driver is dozing off.

The microcomputer 12051 can calculate the control target values of the driving force generating device, steering mechanism, or braking device based on the information inside and outside the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040, and output a control command to the drive system control unit 12010. For example, the microcomputer 12051 can perform cooperative control aimed at realizing the functions of an ADAS (Advanced Driver Assistance System), including vehicle collision avoidance or impact mitigation, following driving based on the distance between vehicles, maintaining vehicle speed, vehicle collision warning, or vehicle lane departure warning.

The microcomputer 12051 can also perform cooperative control for the purpose of autonomous driving, which allows the vehicle to travel autonomously without relying on the driver's operation, by controlling the driving force generating device, steering mechanism, braking device, etc. based on information about the surroundings of the vehicle acquired by the outside vehicle information detection unit 12030 or the inside vehicle information detection unit 12040.

The microcomputer 12051 can also output control commands to the body system control unit 12020 based on information outside the vehicle acquired by the outside-vehicle information detection unit 12030. For example, the microcomputer 12051 can control the headlamps according to the position of a preceding vehicle or an oncoming vehicle detected by the outside-vehicle information detection unit 12030, and perform cooperative control aimed at preventing glare, such as switching high beams to low beams.

The audio/image output unit 12052 transmits at least one output signal of audio and image to an output device capable of visually or audibly notifying the passengers of the vehicle or the outside of the vehicle of information. In the example of FIG. 55, an audio speaker 12061, a display unit 12062, and an instrument panel 12063 are exemplified as output devices. The display unit 12062 may include, for example, at least one of an on-board display and a head-up display.

Figure 56 shows an example of the installation position of the imaging unit 12031.

In FIG. 56, vehicle 12100 has imaging units 12101, 12102, 12103, 12104, and 12105 as imaging unit 12031.

The imaging units 12101, 12102, 12103, 12104, and 12105 are provided, for example, at the front nose, side mirrors, rear bumper, back door, and upper part of the windshield inside the vehicle cabin of the vehicle 12100. The imaging unit 12101 provided at the front nose and the imaging unit 12105 provided at the upper part of the windshield inside the vehicle cabin mainly acquire images of the front of the vehicle 12100. The imaging units 12102 and 12103 provided at the side mirrors mainly acquire images of the sides of the vehicle 12100. The imaging unit 12104 provided at the rear bumper or back door mainly acquires images of the rear of the vehicle 12100. The images of the front acquired by the imaging units 12101 and 12105 are mainly used to detect preceding vehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes, etc.

In addition, FIG. 56 shows an example of the imaging ranges of the imaging units 12101 to 12104. Imaging range 12111 indicates the imaging range of the imaging unit 12101 provided on the front nose, imaging ranges 12112 and 12113 indicate the imaging ranges of the imaging units 12102 and 12103 provided on the side mirrors, respectively, and imaging range 12114 indicates the imaging range of the imaging unit 12104 provided on the rear bumper or back door. For example, an overhead image of the vehicle 12100 viewed from above is obtained by superimposing the image data captured by the imaging units 12101 to 12104.

At least one of the imaging units 12101 to 12104 may have a function of acquiring distance information. For example, at least one of the imaging units 12101 to 12104 may be a stereo camera consisting of multiple imaging elements, or may be an imaging element having pixels for phase difference detection.

For example, the microcomputer 12051 can extract, as a preceding vehicle, the closest three-dimensional object on the path of the vehicle 12100 that is traveling in approximately the same direction as the vehicle 12100 at a predetermined speed (e.g., 0 km/h or faster) by calculating the distance to each three-dimensional object within the imaging range 12111 to 12114 and the change in this distance over time (relative speed with respect to the vehicle 12100) based on the distance information obtained from the imaging units 12101 to 12104. Furthermore, the microcomputer 12051 can set the distance to be secured in advance in front of the preceding vehicle, and perform automatic brake control (including follow-up stop control) and automatic acceleration control (including follow-up start control). In this way, cooperative control can be performed for the purpose of autonomous driving, which runs autonomously without relying on the driver's operation.

For example, the microcomputer 12051 classifies and extracts three-dimensional object data on three-dimensional objects, such as two-wheeled vehicles, ordinary vehicles, large vehicles, pedestrians, utility poles, and other three-dimensional objects, based on the distance information obtained from the imaging units 12101 to 12104, and can use the data to automatically avoid obstacles. For example, the microcomputer 12051 distinguishes obstacles around the vehicle 12100 into obstacles that are visible to the driver of the vehicle 12100 and obstacles that are difficult to see. Then, the microcomputer 12051 determines the collision risk, which indicates the risk of collision with each obstacle, and when the collision risk is equal to or exceeds a set value and there is a possibility of a collision, the microcomputer 12051 can provide driving assistance for collision avoidance by outputting an alarm to the driver via the audio speaker 12061 or the display unit 12062, or by performing forced deceleration or avoidance steering via the drive system control unit 12010.

At least one of the imaging units 12101 to 12104 may be an infrared camera that detects infrared rays. For example, the microcomputer 12051 can recognize a pedestrian by determining whether or not a pedestrian is present in the captured images of the imaging units 12101 to 12104. The recognition of such a pedestrian is performed, for example, by a procedure of extracting feature points in the captured images of the imaging units 12101 to 12104 as infrared cameras, and a procedure of performing pattern matching processing on a series of feature points that indicate the contour of an object to determine whether or not it is a pedestrian. When the microcomputer 12051 determines that a pedestrian is present in the captured images of the imaging units 12101 to 12104 and recognizes the pedestrian, the audio/image output unit 12052 controls the display unit 12062 to superimpose a rectangular contour line for emphasis on the recognized pedestrian. The audio/image output unit 12052 may also control the display unit 12062 to display an icon or the like indicating a pedestrian at a desired position.

The above describes an example of a vehicle control system to which the technology according to the present disclosure can be applied. The technology according to the present disclosure can be applied to the imaging unit 12031 of the configuration described above. Specifically, the above-mentioned light detection device 1 can be applied to the imaging unit 12031. By applying the technology according to the present disclosure to the imaging unit 12031, even if the pixels are miniaturized, it is possible to suppress a decrease in the separation ratio of the phase difference pixels and a decrease in autofocus performance. As a result, it is possible to obtain a captured image that is easier to see.

[Other embodiments]
As described above, the present technology has been described by the first and second embodiments, but the descriptions and drawings forming a part of this disclosure should not be understood as limiting the present technology. Various alternative embodiments, examples, and operating techniques will become apparent to those skilled in the art from this disclosure.

For example, it is possible to combine the technical ideas described in the first to second embodiments. For example, various combinations according to the technical ideas of each embodiment are possible, such as combining the modified examples of the first embodiment described above.

This technology can be applied to all light detection devices, including not only the solid-state imaging devices as image sensors described above, but also distance measurement sensors that measure distance, also known as ToF (Time of Flight) sensors. Distance measurement sensors emit light toward an object, detect the light that is reflected back from the surface of the object, and calculate the distance to the object based on the flight time from when the light is emitted to when the reflected light is received.

The photodetector 1 may also be a stacked CIS (CMOS Image Sensor) in which two or more semiconductor substrates are stacked on top of each other. In this case, the elements of at least one of the logic circuit 13 and the readout circuit 15 may be provided on a substrate different from the semiconductor substrate on which the cell region 20a is provided.

In addition, for example, the materials listed as constituting the above-mentioned components may contain additives, impurities, etc.

As such, the present technology naturally includes various embodiments not described here. Therefore, the technical scope of the present technology is determined only by the invention-specific matters described in the claims that are appropriate from the above explanation.

Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also exist.

The present technology may be configured as follows.
(1)
a semiconductor layer including a plurality of cell regions in which a first photoelectric conversion element and a second photoelectric conversion element are formed adjacent to each other along a first direction in a plan view, and one surface of the semiconductor layer is an element formation surface and the other surface is a light incidence surface;
a refractive optical element having a first portion having a first refractive index and a second portion having a second refractive index higher than the first refractive index, the refractive optical element being provided at a position on the light incident surface side that overlaps with the cell region in a planar view;
Equipped with
one of the refractive optical elements has the first portion at a position close to the first photoelectric conversion element and the second portion at a position close to the second photoelectric conversion element along a first direction;
the other refractive optical element has the second portion at a position closer to the first photoelectric conversion element along the first direction, and has the first portion at a position closer to the second photoelectric conversion element along the first direction;
Light detection device.
(2)
The optical detection device according to (1), wherein a difference between the first refractive index and the second refractive index is 0.2 or more and 0.5 or less.
(3)
The optical detection device according to (1) or (2), wherein in the refractive optical element, the size of the area occupied by the second portion in a planar view is the same as or larger than the size of the area occupied by the first portion.
(4)
The optical detection device of any one of (1) to (3), wherein, in a planar view, the second portion of the refractive optical element has a larger area overlapping with the center of the cell region in a planar view than the first portion.
(5)
The optical detection device according to (4), wherein, in a plan view, the second portion has a central portion in a second direction perpendicular to the first direction that is located closer to the first portion than the end portion.
(6)
The optical detection device according to any one of (1) to (5), wherein the refractive optical element has a thickness of 30 nm or more and 200 nm or less.
(7)
a third portion is provided between the first portion and the second portion,
The optical detection device according to any one of (1) to (6), wherein a third refractive index, which is a refractive index of the third portion, is different from the first refractive index and the second refractive index.
(8)
a color filter provided on the light incident surface side of the semiconductor layer;
The photodetector according to any one of (1) to (7), wherein the refractive optical element is provided between the light incident surface of the semiconductor layer and the color filter.
(9)
the cell region in which the first photoelectric conversion element and the second photoelectric conversion element are configured is provided in a matrix in a pixel region,
The optical detection device according to any one of (1) to (8), wherein the refractive optical element is provided for each of the cell regions.
(10)
The light detection device according to any one of (1) to (9), wherein an anti-reflection film is provided on at least one of one side and the other side in a thickness direction of the refractive optical element.
(11)
A photodetection device described in any one of (1) to (10), wherein the sum of the signal charge generated in the first photoelectric conversion element and the signal charge generated in the second photoelectric conversion element constitutes a pixel signal for forming one pixel of image data.
(12)
a light detection device and an optical system that forms an image of light from a subject on the light detection device;
The light detection device includes:
a semiconductor layer including a plurality of cell regions in which a first photoelectric conversion element and a second photoelectric conversion element are formed adjacent to each other along a first direction in a plan view, one surface of which is an element formation surface and the other surface of which is a light incidence surface;
a refractive optical element having a first portion having a first refractive index and a second portion having a second refractive index higher than the first refractive index, the refractive optical element being provided at a position on the light incident surface side that overlaps with the cell region in a planar view;
Equipped with
one of the refractive optical elements has the first portion at a position close to the first photoelectric conversion element and the second portion at a position close to the second photoelectric conversion element along a first direction;
Another of the refractive optical elements has the second portion at a position closer to the first photoelectric conversion element along the first direction, and has the first portion at a position closer to the second photoelectric conversion element along the first direction.
Electronic devices.

The scope of the present technology is not limited to the exemplary embodiments shown and described, but includes all embodiments that achieve the same effect as the intended purpose of the present technology. Furthermore, the scope of the present technology is not limited to the combination of the features of the invention defined by the claims, but may be defined by any desired combination of specific features among all the respective features disclosed.

REFERENCE SIGNS LIST 1 Photodetector 2A Pixel region 3, 3L, 3R, 3LO, 3UP Pixel 20 Semiconductor layer 20a, 20aL, 20aR, 20aLO, 20aUP Cell region 30 Refractive optical element layer 31, 31L, 31R, 31LO, 31UP Refractive optical element 32 First portion 33 Second portion 34 Third portion 41 Color filter 1000 Electronic device 1011 Optical system m4, m5 Anti-reflection film n1 First refractive index n2 Second refractive index n3 Third refractive index PD, PD1, PD2 Photoelectric conversion element

Claims (12)

a semiconductor layer including a plurality of cell regions in which a first photoelectric conversion element and a second photoelectric conversion element are formed adjacent to each other along a first direction in a plan view, and one surface of the semiconductor layer is an element formation surface and the other surface is a light incidence surface;
a refractive optical element having a first portion having a first refractive index and a second portion having a second refractive index higher than the first refractive index, the refractive optical element being provided at a position on the light incident surface side that overlaps with the cell region in a planar view;
Equipped with
one of the refractive optical elements has the first portion at a position close to the first photoelectric conversion element and the second portion at a position close to the second photoelectric conversion element along a first direction;
Another of the refractive optical elements has the second portion at a position closer to the first photoelectric conversion element along the first direction, and has the first portion at a position closer to the second photoelectric conversion element along the first direction.
Light detection device. The optical detection device according to claim 1, wherein the difference between the first refractive index and the second refractive index is 0.2 or more and 0.5 or less. The optical detection device according to claim 1, wherein in the refractive optical element, the size of the area occupied by the second portion in a plan view is equal to or larger than the size of the area occupied by the first portion. The optical detection device according to claim 1, wherein in the refractive optical element, the second portion has a larger area overlapping the center of the cell region in a planar view than the first portion in a planar view. The light detection device according to claim 4, wherein the second portion has a center portion in a second direction perpendicular to the first direction, the center portion being located closer to the first portion than the end portion in a plan view. The optical detection device of claim 1, wherein the thickness of the refractive optical element is 30 nm or more and 200 nm or less. a third portion is provided between the first portion and the second portion,
The optical detection device according to claim 1 , wherein a third refractive index of the third portion is different from the first refractive index and the second refractive index. a color filter provided on the light incident surface side of the semiconductor layer;
The photodetector according to claim 1 , wherein the refractive optical element is provided between the light incident surface of the semiconductor layer and the color filter. the cell region in which the first photoelectric conversion element and the second photoelectric conversion element are configured is provided in a matrix in a pixel region,
The photodetector according to claim 1 , wherein the refractive optical element is provided for each of the cell regions. The optical detection device according to claim 1, wherein an anti-reflection film is provided on at least one of the first and second sides of the refractive optical element in the thickness direction. The photodetection device according to claim 1, wherein the sum of the signal charge generated in the first photoelectric conversion element and the signal charge generated in the second photoelectric conversion element constitutes a pixel signal for forming one pixel of image data. a light detection device and an optical system that forms an image of light from a subject on the light detection device;
The light detection device includes:
a semiconductor layer including a plurality of cell regions in which a first photoelectric conversion element and a second photoelectric conversion element are formed adjacent to each other along a first direction in a plan view, one surface of which is an element formation surface and the other surface of which is a light incidence surface;
a refractive optical element having a first portion having a first refractive index and a second portion having a second refractive index higher than the first refractive index, the refractive optical element being provided at a position on the light incident surface side that overlaps with the cell region in a planar view;
Equipped with
one of the refractive optical elements has the first portion at a position close to the first photoelectric conversion element and the second portion at a position close to the second photoelectric conversion element along a first direction;
the other refractive optical element has the second portion at a position closer to the first photoelectric conversion element along the first direction, and has the first portion at a position closer to the second photoelectric conversion element along the first direction;
Electronic devices.

Images