Light detection device and electronic equipment

Abstract

Suppresses the mixing of colors of light. [Solution] A photodetector is provided, comprising a pixel array section in which a plurality of pixels are arranged in a two-dimensional array, including a first pixel having a plurality of photoelectric conversion units formed on a single microlens, the first pixel being provided with a first separation section for separating the plurality of photoelectric conversion units, the first separation section separating the portion corresponding to the focusing position by the microlens using an impurity region formed on the semiconductor substrate on which the plurality of photoelectric conversion units are formed, and separating the portion excluding the portion corresponding to the impurity region by embedding a material in a trench formed on the semiconductor substrate. This disclosure can be applied, for example, to solid-state imaging devices such as CMOS type image sensors.

Description

Technical Field

[0001] The present disclosure relates to an optical detection device and an electronic device, and particularly to an optical detection device and an electronic device capable of suppressing color mixing of light.

Background Art

[0002] As one of the autofocus methods, a so-called image plane phase difference method is known in which phase difference detection for focus detection is performed using pixels for phase difference detection. As the pixels for phase difference detection, pixels in which a plurality of photoelectric conversion units are formed for one microlens can be used (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In pixels for phase difference detection, when a configuration in which a plurality of photoelectric conversion units are formed for one microlens is adopted, there is a risk that light reflected by the separation part in the pixel enters other adjacent pixels and causes color mixing. Therefore, when using pixels for phase difference detection, it has been required to suppress color mixing of light.

[0005] The present disclosure has been made in view of such a situation and is intended to suppress color mixing of light.

Means for Solving the Problems

[0006] One aspect of the present disclosure is a photodetector comprising a pixel array portion in which a plurality of pixels are arranged in a two-dimensional array, including a first pixel having a plurality of photoelectric conversion units formed on a single microlens, the first pixel being provided with a first separation portion for separating the plurality of photoelectric conversion units, the first separation portion separating a portion corresponding to the focusing position by the microlens with an impurity region formed on the semiconductor substrate on which the plurality of photoelectric conversion units are formed, and separating the portion excluding the portion corresponding to the impurity region by embedding a substance in a trench formed on the semiconductor substrate.

[0007] An electronic device relating to one aspect of the present disclosure comprises a photodetector and a control unit that performs autofocus control based on phase difference information obtained from the photodetector, wherein the photodetector has a pixel array unit in which a plurality of pixels, including a first pixel having a plurality of photoelectric conversion units formed on a single microlens, are arranged in a two-dimensional array, the first pixel is provided with a first separation unit that separates the plurality of photoelectric conversion units, the first separation unit separates a portion corresponding to the focusing position by the microlens by an impurity region formed on a semiconductor substrate on which the plurality of photoelectric conversion units are formed, and separates the portion excluding the portion corresponding to the impurity region by embedding a substance in a trench formed on the semiconductor substrate.

[0008] Furthermore, the photodetector, which is one aspect of this disclosure, may be an independent device or an internal block constituting a single device. [Brief explanation of the drawing]

[0009] [Figure 1] This figure shows an example configuration of one embodiment of a photodetector to which the present disclosure applies. [Figure 2] This figure shows a first example of the pixel configuration. [Figure 3] This figure shows a second example of the pixel configuration. [Figure 4] This figure shows a third example of the pixel configuration. [Figure 5] This figure shows a fourth example of the pixel configuration. [Figure 6] This figure shows a fifth example of the pixel configuration. [Figure 7] This figure shows a sixth example of the pixel configuration. [Figure 8] This figure shows the seventh example of pixel configuration. [Figure 9] This figure shows an eighth example of the pixel configuration. [Figure 10] This figure shows the ninth example of pixel configuration. [Figure 11] This figure shows the tenth example of the pixel configuration. [Figure 12] This figure shows the eleventh example of pixel configuration. [Figure 13] This figure shows an example configuration of one embodiment of an electronic device equipped with a photodetector to which the present disclosure applies. [Modes for carrying out the invention]

[0010] <Device configuration> Figure 1 shows an example configuration of one embodiment of a photodetector to which the present disclosure is applied. The photodetector 1 is configured as a solid-state imaging device such as a CMOS (Complementary Metal Oxide Semiconductor) type image sensor. As shown in Figure 1, the photodetector 1 consists of a pixel array unit 21, a vertical drive unit 22, a column signal processing unit 23, a horizontal drive unit 24, an output unit 25, and a control unit 26.

[0011] The pixel array section 21 has a plurality of pixels 31 arranged in a two-dimensional array on a semiconductor substrate made of silicon (Si) or the like. Each pixel 31 has a photoelectric conversion section composed of a photodiode (PD), a pixel transistor, and the like. For each row of the plurality of pixels 31 arranged in a two-dimensional array in the pixel array section 21, a pixel drive line 32 is formed and connected to a vertical drive section 22, and a vertical signal line 33 is formed for each column and connected to a column signal processing section 23.

[0012] The vertical driving unit 22 is composed of a shift register, an address decoder, etc., and drives each pixel 31 arranged in the pixel array unit 21. The signal output from the pixel 31 selected and scanned by the vertical driving unit 22 is supplied to the column signal processing unit 23 through the vertical signal line 33. The column signal processing unit 23 performs predetermined signal processing (such as AD conversion processing, etc.) on the signal output from each pixel 31 of the selected row through the vertical signal line 33 for each pixel column of the pixel array unit 21, and temporarily holds the signal after the signal processing.

[0013] The horizontal driving unit 24 is composed of a shift register, an address decoder, etc., and sequentially selects unit circuits corresponding to the pixel columns of the column signal processing unit 23. By the selective scanning by the horizontal driving unit 24, the signal processed by the column signal processing unit 23 is output to the output unit 25 through the horizontal signal line 34. The output unit 25 performs predetermined signal processing on the signals sequentially input from each of the column signal processing units 23 through the horizontal signal line 34, and outputs the resulting signal.

[0014] The control unit 26 is composed of a timing generator that generates various timing signals, etc., and performs drive control of the vertical driving unit 22, the column signal processing unit 23, the horizontal driving unit 24, etc. based on the various timing signals generated by the timing generator.

[0015] <Configuration of Pixel> Hereinafter, the configuration of the pixel 31 arranged in a two-dimensional array in the pixel array unit 21 in the photodetection device 1 will be described.

[0016] <<First Embodiment>> FIG. 2 is a diagram showing a first example of the configuration of the pixel 31. In FIG. 2, among a plurality of pixels 31 arranged in a two-dimensional array in the pixel array unit 21, examples of the layouts of the pixels 31R, 31G, and 31B arranged in a predetermined pattern in a partial region are shown.

[0017] Pixel 31R is equipped with a color filter 52R corresponding to the red wavelength band, and is a pixel that generates an electric charge corresponding to the red component of light from the light transmitted through the color filter 52R. Pixel 31G is equipped with a color filter 52G corresponding to the green wavelength band, and is a pixel that generates an electric charge corresponding to the green component of light from the light transmitted through the color filter 52G. Pixel 31B is equipped with a color filter 52B corresponding to the blue wavelength band, and is a pixel that generates an electric charge corresponding to the blue component of light from the light transmitted through the color filter 52B.

[0018] In Figure 2, pixel 31R is located in the lower left region (2x2 region), pixel 31G is located in the upper left and lower right regions (2x2 regions), and pixel 31B is located in the upper right region (2x2 region). In Figure 2, pixel 31G is a normal pixel, while pixels 31R and 31B are pixels used for phase difference detection.

[0019] Pixel 31R has a structure in which two photoelectric conversion units 53-1 and 53-2 are provided for one microlens 51. In pixel 31R, light focused by the horizontally elongated elliptical microlens 51 passes through the color filter 52R and is incident on the photoelectric conversion units 53-1 and 53-2. Pixel 31G has a structure in which one photoelectric conversion unit 53 is provided for one microlens 51. In pixel 31G, light focused by the circular microlens 51 passes through the color filter 52G and is incident on the photoelectric conversion unit 53. Pixel 31B has a structure in which two photoelectric conversion units 53-1 and 53-2 are provided for one microlens 51. In pixel 31B, light focused by the horizontally elongated elliptical microlens 51 passes through the color filter 52B and is incident on the photoelectric conversion units 53-1 and 53-2.

[0020] In Figure 2, the inter-pixel isolation section 71 is formed in a grid pattern so as to surround the photoelectric conversion section of each pixel 31, pixel 31R, pixel 31G, and pixel 31B. The inter-pixel isolation section 71 is formed, for example, by embedding a substance (material) such as tungsten or an oxide film in a trench formed in the semiconductor substrate on which the photoelectric conversion section is formed. Here, if the side of the main surface of the semiconductor substrate on which the wiring layer is provided is considered the front surface and the side opposite to the front surface is considered the back surface, then, for example, the inter-pixel isolation section 71 can be formed by embedding a substance in a trench formed from the back surface side of the semiconductor substrate. The trench may be a non-penetrating trench that does not penetrate to the front surface side of the semiconductor substrate.

[0021] In pixel 31R, an inter-element isolation section 72 is formed to separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed with respect to the horizontally elongated elliptical microlens 51, to the left and right. The inter-element isolation section 72 is an in-pixel isolation section that separates the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2 within pixel 31R. Similar to the inter-pixel isolation section 71, the inter-element isolation section 72 is constructed by embedding a substance such as tungsten or an oxide film in a trench formed in the semiconductor substrate. The inter-element isolation section 72 is formed as a protrusion by projecting toward the center of pixel 31R.

[0022] In other words, the element-to-element isolation section 72 is formed as a projection that protrudes from a predetermined part of the grid-like inter-pixel isolation section 71, and the projections protruding from opposing parts do not contact the center of the pixel 31R, and the structure is such that the part corresponding to the focusing point by the microlens 51 is hollowed out. In the pixel 31R, the region including the center corresponding to the focusing point (hereinafter also referred to as the central region) is separated by the impurity isolation section 61 as shown by the dashed line in the figure. The impurity isolation section 61 separates the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2 within the pixel 31R with an impurity region. For example, in a semiconductor substrate, when the photoelectric conversion sections 53-1 and 53-2 are composed of photodiodes (PDs) with n-type regions, the impurity isolation section 61 can be formed with a p-type impurity region.

[0023] Thus, in pixel 31R, the photoelectric conversion units 53-1 and 53-2, which are formed on the horizontally elongated elliptical microlens 51, are separated into left and right parts as an inter-element separation unit 72 and an impurity separation unit 61 within the pixel. Here, the inter-element separation unit 72 has a shape in which the central region corresponding to the light-gathering point is hollowed out, and the portion corresponding to the hollowed-out shape is separated by the impurity separation unit 61. As a result, in pixel 31R, the photoelectric conversion units 53-1 and 53-2 are separated by impurities in the central region corresponding to the light-gathering point by the impurity separation unit 61, and the portion excluding the central region is physically separated by the inter-element separation unit 72.

[0024] In pixel 31B, the photoelectric conversion units 53-1 and 53-2, which are formed on the horizontally elongated elliptical microlens 51, are separated into left and right parts by an inter-element separation unit 73 and an impurity separation unit 62, which are formed as in-pixel separation units. In pixel 31B, similar to pixel 31R, the central region of the photoelectric conversion unit 53-1 and the photoelectric conversion unit 53-2 corresponding to the light-gathering point is separated by impurities by the impurity separation unit 62, and the portion excluding the central region is physically separated by the inter-element separation unit 73.

[0025] As described above, in pixels 31R and 31B, which are configured as pixels for phase difference detection, an impurity separation section 61, 62 is provided as an in-pixel separation section to separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2. This section separates the central region corresponding to the focal point (focal position), and the inter-element separation sections 72, 73 separate the portion excluding the central region. Thus, the central region corresponding to the focal point is separated by impurities rather than physical separation. In this way, by providing a physical separation section with a portion corresponding to the focal point cut out as an in-pixel separation section, and separating the cut-out portion with impurities, it is possible to suppress color mixing caused by light reflected from the in-pixel separation section entering other adjacent pixels.

[0026] For example, as shown in Figure 2, when light focused by the microlens 51 is incident on the central region of pixel 31R from the direction indicated by arrow A1, the central region is provided with an impurity separation section 61 as a separation section. Therefore, the light is not reflected as it would be if a physical separation section were provided (dashed arrow in the figure), and as a result, the reflected light does not incident on other pixels. For example, it is possible to prevent light reflected by the internal separation section of pixel 31R from incident on pixel 31G. Thus, color mixing of light can be suppressed.

[0027] In the pixel array section 21, pixels for phase difference detection are arranged along with normal pixels. The normal pixels include pixels 31G, 31R, and 31B. Specifically, the pixel array section 21 has pixels 31R, 31G, and 31B arranged in a predetermined pattern, each consisting of a microlens 51 and a photoelectric conversion unit 53. The photodetector 1 can generate a signal for generating an image from the signals obtained from the normal pixels. The photodetector 1 can perform image plane phase difference autofocus control based on the signals obtained from the phase difference detection pixels.

[0028] The element-to-element separation section 72 may be made of the same material as the pixel-to-pixel separation section 71, or it may be made of a different material. If the element-to-element separation section 72 is made of the same material as the pixel-to-pixel separation section 71, the pixel-to-pixel separation section 71 and the element-to-element separation section 72 can be made as a single unit. Note that in Figure 2, arrows such as arrow A1 and the dashed lines indicating the impurity separation sections 61 and 62 are included for illustrative purposes only and do not actually exist.

[0029] <<Second Embodiment>> Figure 3 shows a second example of the configuration of pixel 31. In Figure 3, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0030] In Figure 3, in pixel 31R, which is configured as a pixel for phase difference detection, the width (line width) of the inter-element separation portion 72 is formed to be narrower than the width (line width) of the inter-pixel separation portion 71, which is formed in a grid pattern in a plan view. In pixel 31B, which is configured as a pixel for phase difference detection, the width (line width) of the inter-element separation portion 73 is formed to be narrower than the width (line width) of the inter-pixel separation portion 71 in a plan view. In other words, in the separation portion consisting of the inter-pixel separation portion 71 and the inter-element separation portions 72 and 73, the width of the separation portion between different colors is made wider, while the width of the separation portion between same colors is made narrower.

[0031] Furthermore, in pixel 31R, the photoelectric conversion units 53-1 and 53-2 are separated by impurities in the central region by the impurity separation unit 61, and the remaining portion is physically separated by the inter-element separation unit 72. In pixel 31B, the photoelectric conversion units 53-1 and 53-2 are separated by impurities in the central region by the impurity separation unit 62, and the remaining portion is physically separated by the inter-element separation unit 73.

[0032] As described above, in pixels 31R and 31B, which are configured as pixels for phase difference detection, an impurity separation unit 61, 62 is provided as an intra-pixel separation unit to separate the central region corresponding to the light collection point, and an inter-element separation unit 72, 73 is provided to separate the portion excluding the central region. This suppresses color mixing caused by light reflected by the intra-pixel separation unit entering other adjacent pixels. For example, as shown in Figure 3, when light is incident on the central region of pixel 31R from the direction indicated by arrow A1, the impurity separation unit 61 is provided in the central region, so the reflected light does not enter other pixels, and color mixing of light can be suppressed.

[0033] Furthermore, by making the width of the inter-pixel separation section 71 wider than the width of the inter-element separation sections 72 and 73, the width of the separation section between different colors is increased, and by making the width of the inter-element separation sections 72 and 73 narrower than the width of the inter-pixel separation section 71, the width of the separation section between the same colors is reduced, further suppression of color mixing is possible, and sensitivity can be improved.

[0034] <<Third Embodiment>> Figure 4 shows a third example of the configuration of pixel 31. In Figure 4, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0035] In Figure 4, the color filters 52R, 52G, and 52B of pixel 31 are arranged in a Bayer array, with pixel 31G arranged in a checkerboard pattern, and pixels 31R and 31B alternating in rows in the remaining areas. In Figure 4, pixels 31R, 31G, and 31B are arranged as normal pixels, each consisting of one photoelectric conversion unit 53 attached to one microlens 51. Additionally, pixel 31R is arranged as a pixel for phase difference detection, each consisting of two photoelectric conversion units 53-1 and 53-2 attached to one microlens 51.

[0036] In the example shown in Figure 4, among the regular pixels arranged in a Bayer array, pixel 31R, which is configured as a pixel for phase difference detection, is placed in the position where pixels 31G and 31B are placed as two adjacent pixels (left and right) in the lower left region. In other words, a pixel for phase difference detection is placed in place of the two adjacent pixels. Since it is preferable to use a color filter of the same color for the pixel for phase difference detection, pixel 31R, which is equipped with a color filter 52R, is placed in place of the two adjacent pixels (pixels 31G and 31B).

[0037] In pixel 31R, which is configured as a pixel for phase difference detection, an inter-element separation section 72 and an impurity separation section 61 are formed as in-pixel separation sections that separate the photoelectric conversion sections 53-1 and 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts. In pixel 31R, the central region of photoelectric conversion sections 53-1 and 53-2 is separated by impurities by the impurity separation section 61, and the parts excluding the central region are physically separated by the inter-element separation section 72.

[0038] As described above, when a Bayer array is adopted as a predetermined pattern, in a pixel 31R configured as a pixel for phase difference detection, an impurity separation unit 61 that separates the central region corresponding to the light collection point and an inter-element separation unit 72 that separates the portion excluding the central region are provided as intra-pixel separation units. This suppresses color mixing caused by light reflected by the intra-pixel separation unit entering other adjacent pixels. For example, as shown in Figure 4, when light is incident on the central region of pixel 31R from the direction indicated by arrow A1, the central region is provided with an impurity separation unit 61, so the reflected light does not enter other pixels, thus suppressing color mixing of the light.

[0039] <<Fourth Embodiment>> Figure 5 shows a fourth example of the configuration of pixel 31. In Figure 5, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0040] In Figure 5, in pixel 31R, which is configured as a pixel for phase difference detection, the photoelectric conversion units 53-1 and 53-2 formed on the horizontally elongated elliptical microlens 51 are separated into left and right parts by an inter-element separation unit 72 and an impurity separation unit 61. In pixel 31R, the focusing point of the microlens 51 is located in a region different from the central region (a predetermined region including the part below the center), and the inter-element separation unit 72 has a shape in which the part corresponding to the predetermined region is cut out. Furthermore, the part corresponding to the cut-out shape is separated by the impurity separation unit 61. In other words, in pixel 31R, the parts of the photoelectric conversion units 53-1 and 53-2 in the predetermined region (a region different from the central region) are separated by impurities by the impurity separation unit 61, and the parts excluding the predetermined region are physically separated by the inter-element separation unit 72.

[0041] In pixel 31B, which is configured as a pixel for phase difference detection, an element-to-element separation section 73 and an impurity separation section 62 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right sections. In pixel 31B, similar to pixel 31R, the photoelectric conversion sections 53-1 and 53-2 are separated by impurities in a predetermined region (a region different from the central region) corresponding to the focusing point by the impurity separation section 62, and the portion excluding the predetermined region is physically separated by the element-to-element separation section 73.

[0042] As described above, in pixels 31R and 31B, which are configured as pixels for phase difference detection, an impurity separation unit 61, 62 is provided as an intrapixel separation unit that separates a predetermined region (a region different from the central region) corresponding to the light collection point, and an inter-element separation unit 72, 73 is provided that separates the portion excluding the predetermined region (for example, the portion including the central region). This makes it possible to suppress color mixing caused by light reflected by the intrapixel separation unit being incident on other adjacent pixels.

[0043] In Figure 5, the microlenses 51 of pixels 31R and 31B are shown in an ideal state. However, during manufacturing, the microlenses 51 may not be in an ideal state, and the light-gathering point may shift from the central region. In Figure 5, the cutout position of the pixel separation portion is optimized. For example, in pixel 31R, when the microlens 51 is formed on the lower side with the vertical direction narrowed in the figure, the impurity separation portion 61 is formed in a predetermined region that includes the area below the center. This prevents light incident from the direction indicated by arrow A1 from being reflected and incident on other pixels, thereby suppressing light mixing.

[0044] <<Fifth Embodiment>> Figure 6 shows a fifth example of the configuration of pixel 31. In Figure 6, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0045] In Figure 6, pixel 31R is located in the upper left region (2x2 region), pixel 31G is located in the lower left and upper right regions (2x2 regions), and pixel 31B is located in the lower right region (2x2 region). In Figure 6, pixel 31G is a normal pixel, while pixels 31R and 31B are pixels used for phase difference detection.

[0046] In Figure 6, in pixel 31R, an inter-element separation section 72 and an impurity separation section 61 are formed as in-pixel separation sections that separate the photoelectric conversion sections 53-1 and 53-2, which are formed on a vertically elongated elliptical microlens 51, into upper and lower parts. In pixel 31R, the central region of the photoelectric conversion sections 53-1 and 53-2 is separated by impurities by the impurity separation section 61, and the parts excluding the central region are physically separated by the inter-element separation section 72.

[0047] In pixel 31B, an inter-element separation section 73 and an impurity separation section 62 are formed as in-pixel separation sections that separate the photoelectric conversion sections 53-1 and 53-2, which are formed on a vertically elongated elliptical microlens 51, into upper and lower parts. In pixel 31B, the central region of the photoelectric conversion sections 53-1 and 53-2 is separated by impurities by the impurity separation section 62, and the parts excluding the central region are physically separated by the inter-element separation section 73.

[0048] As described above, pixels 31R and 31B, which are configured as pixels for phase difference detection, are arranged to correspond to two adjacent pixels in a predetermined direction (vertical direction) in a normal pixel (for example, pixel 31G) arranged in a predetermined pattern. In pixels 31R and 31B, impurity separation units 61 and 62 are provided as intrapixel separation units, which separate the central region corresponding to the light collection point, and inter-element separation units 72 and 73 separate the portion excluding the central region. This suppresses color mixing caused by light reflected by the intrapixel separation unit entering other adjacent pixels. For example, as shown in Figure 6, when light enters the central region of pixel 31R from the direction indicated by arrow A1, the central region is provided with an impurity separation unit 61, so the reflected light does not enter other pixels, and color mixing of light can be suppressed.

[0049] Figure 7 shows a sixth example of the configuration of pixel 31. In Figure 7, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0050] In Figure 7, pixel 31R is located in the lower left region (2x2 region), pixel 31G is located in the upper left and lower right regions (2x2 regions), and pixel 31B is located in the upper right region (2x2 region). In Figure 7, pixel 31G is a normal pixel, while pixels 31R and 31B are pixels used for phase difference detection.

[0051] In Figure 7, in pixel 31R, the photoelectric conversion units 53-1 and 53-2, which are formed on a horizontally elongated elliptical microlens 51, are separated into left and right parts as an inter-element separation unit 72 and an impurity separation unit 61 within the pixel. In pixel 31R, the central region of the photoelectric conversion units 53-1 and 53-2 is separated by impurities by the impurity separation unit 61, and the portion excluding the central region is physically separated by the inter-element separation unit 72.

[0052] In pixel 31B, an inter-element separation section 73 and an impurity separation section 62 are formed as in-pixel separation sections that separate the photoelectric conversion sections 53-1 and 53-2, which are formed on a vertically elongated elliptical microlens 51, into upper and lower parts. In pixel 31B, the central region of the photoelectric conversion sections 53-1 and 53-2 is separated by impurities by the impurity separation section 62, and the parts excluding the central region are physically separated by the inter-element separation section 73.

[0053] As described above, the pixel 31R, which is configured as a pixel for phase difference detection, is arranged to correspond to two adjacent pixels in a first direction (left-right direction) in a normal pixel (for example, pixel 31G) arranged in a predetermined pattern, and the pixel 31B is arranged to correspond to two adjacent pixels in a second direction (up-down direction) different from the first direction (left-right direction). In pixels 31R and 31B, an impurity separation section 61, 62 is provided as an intrapixel separation section that separates the central region corresponding to the light collection point, and an inter-element separation section 72, 73 separates the portion excluding the central region. This makes it possible to suppress color mixing caused by light reflected by the intrapixel separation section entering other adjacent pixels.

[0054] For example, as shown in Figure 7, when light is incident on the central region of pixel 31R from the direction indicated by arrow A1, the central region is provided with an impurity separation unit 61, so the reflected light does not enter other pixels, and the mixing of light can be suppressed. Similarly, when light is incident on the central region of pixel 31B from the direction indicated by arrow A2, the central region is provided with an impurity separation unit 62, so the reflected light does not enter other pixels, and the mixing of light can be suppressed.

[0055] <<Sixth Embodiment>> Figure 8 shows a seventh example of the configuration of pixel 31. In Figure 8, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0056] In Figure 8, in pixel 31R, which is configured as a pixel for phase difference detection, the width (line width) of the inter-element isolation portion 72 is formed to be narrower than the width (line width) of the inter-element isolation portion 73 of pixel 31B in a plan view. In pixel 31B, which is configured as a pixel for phase difference detection, the width (line width) of the inter-element isolation portion 73 is formed to be wider than the width (line width) of the inter-element isolation portion 72 of pixel 31R in a plan view. That is, the red wavelength band has a longer wavelength than the green and blue wavelength bands and has the characteristic of being easily reflected and propagated, so here the width of the inter-element isolation portion 72 of pixel 31R is made particularly narrow. Note that the width of the inter-element isolation portion 72 of pixel 31R and the width of the inter-element isolation portion 73 of pixel 31B may be formed to be narrower than the width of the inter-element isolation portion 71.

[0057] Furthermore, in pixel 31R, the photoelectric conversion units 53-1 and 53-2 are separated by impurities in the central region by the impurity separation unit 61, and the remaining portion is physically separated by the inter-element separation unit 72. In pixel 31B, the photoelectric conversion units 53-1 and 53-2 are separated by impurities in the central region by the impurity separation unit 62, and the remaining portion is physically separated by the inter-element separation unit 73.

[0058] As described above, in pixels 31R and 31B, which are configured as pixels for phase difference detection, an impurity separation section 61, 62 is provided as an intra-pixel separation section that separates the central region corresponding to the light collection point, and an inter-element separation section 72, 73 is provided that separates the portion excluding the central region. This makes it possible to suppress color mixing caused by light reflected by the intra-pixel separation section entering other adjacent pixels.

[0059] Here, in the pixels used for phase difference detection, the width of the inter-element isolation portion may differ in a plan view depending on the wavelength band corresponding to the color filter 52. Specifically, by making the width of the inter-element isolation portion 72 of the pixel 31R equipped with a color filter 52R corresponding to the long wavelength red wavelength band particularly narrow, reflection of long wavelengths can be suppressed, and color mixing can be suppressed. For example, as shown in Figure 8, when light is incident on the pixel 31R from the direction indicated by arrow A1, reflection of light corresponding to the long wavelength red wavelength band can be suppressed, and color mixing caused by light reflected by the inter-element isolation portion 72 being incident on other adjacent pixels can be reduced.

[0060] Figure 9 shows an eighth example of the configuration of pixel 31. In Figure 9, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0061] In Figure 9, in pixel 31R, which is configured as a pixel for phase difference detection, an inter-element separation section 72 is formed as an in-pixel separation section that separates the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on the horizontally elongated elliptical microlens 51, into left and right sections. In pixel 31B, which is configured as a pixel for phase difference detection, an inter-element separation section 73 is formed as an in-pixel separation section that separates the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on the horizontally elongated elliptical microlens 51, into left and right sections.

[0062] In other words, in pixels 31R and 31B, the photoelectric conversion unit 53-1 and the photoelectric conversion unit 53-2 are physically separated by the inter-element separation units 72 and 73. Furthermore, the width (line width) of the inter-element separation unit 72 of pixel 31R and the width (line width) of the inter-element separation unit 73 of pixel 31B are formed to be narrower than the width (line width) of the inter-element separation unit 71 in a plan view.

[0063] As described above, in pixels 31R and 31B, which are configured as pixels for phase difference detection, by providing inter-elemental separation sections 72 and 73, which are narrower than the inter-pixel separation section 71, as intra-pixel separation sections, color mixing caused by light reflected by the inter-elemental separation sections 72 and 73 entering other adjacent pixels can be suppressed. For example, as shown in Figure 9, when light enters the inter-elemental separation section 72 of pixel 31R from the direction indicated by arrow A1, the narrower inter-elemental separation section 72 reduces color mixing caused by reflected light entering other pixels.

[0064] <<Seventh Embodiment>> Figure 10 shows a ninth example of the configuration of pixel 31. In Figure 10, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0065] In Figure 10, in pixel 31R, which is configured as a pixel for phase difference detection, an inter-element separation section 72 and an impurity separation section 61 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts. In pixel 31B, which is configured as a pixel for phase difference detection, an inter-element separation section 73 and an impurity separation section 62 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts.

[0066] In pixel 31R, the portion corresponding to the central region of the inter-element isolation section 72 is hollowed out, and a part of the internal pixel isolation section is composed of an impurity isolation section 61, which is an impurity region formed on the semiconductor substrate. As a result, the state of the semiconductor (silicon) constituting the semiconductor substrate changes, causing the potential to fluctuate. Similarly, in pixel 31B, the inter-element isolation section 73 is hollowed out, and a part of the internal pixel isolation section is composed of an impurity isolation section 62. As a result, the state of the semiconductor changes, causing the potential to fluctuate. These potential fluctuations may cause the sensitivity of each pixel to become non-uniform, but the sensitivity of each pixel can be adjusted by changing the width (line width) of the inter-element isolation sections 72 and 73.

[0067] In Figure 10, the width (line width) of the inter-element isolation section 72 of pixel 31R is made thicker than the width (line width) of the inter-element isolation section 73 of pixel 31B in a plan view. Also in Figure 10, the width of the inter-element isolation section 72 of pixel 31R is thicker than the width of the inter-pixel isolation section 74 that separates the pixels 31G, and the width of the inter-element isolation section 73 of pixel 31B is thinner than the width of the inter-pixel isolation section 74. Here, the widths of the inter-element isolation sections 72 and 73 are adjusted to adjust for the effect of potential fluctuations caused by hollowing out the inter-element isolation sections 72 and 73 to form impurity isolation sections 61 and 62.

[0068] In this way, by adjusting the width of the inter-element isolation section 72 of pixel 31R and the inter-element isolation section 73 of pixel 31B according to the state of the semiconductor constituting the semiconductor substrate, the sensitivity of each pixel can be made uniform. That is, when the inter-element isolation sections 72 and 73 are hollowed out to form impurity isolation sections 61 and 62, the state of the semiconductor changes and the potential fluctuates. Therefore, the width of the inter-element isolation sections 72 and 73, which have a hollowed-out shape, is adjusted to match the inter-pixel isolation section 74, which does not have a hollowed-out shape. In addition, the width of the inter-pixel isolation section 74 may be adjusted along with the width of the inter-element isolation sections 72 and 73.

[0069] Figure 11 shows a tenth example of the configuration of pixel 31. In Figure 11, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0070] In Figure 11, in pixel 31R, which is configured as a pixel for phase difference detection, an inter-element separation section 72 and an impurity separation section 61 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts. In pixel 31B, which is configured as a pixel for phase difference detection, an inter-element separation section 73 and an impurity separation section 62 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts.

[0071] In Figure 11, in pixel 31G, which is configured as a normal pixel, a photoelectric conversion section 53 is formed on a circular microlens 51. In addition, an inter-pixel separation section 74 and an impurity separation section 63 are formed to separate the pixels 31G horizontally. Specifically, as an inter-pixel separation section that separates the pixels 31G horizontally, similar to the intra-pixel separation sections of pixels 31R and 31B, a part of the inter-pixel separation section 74 that physically separates the pixels 31G is hollowed out, and a part of the inter-pixel separation section is composed of an impurity separation section 63, which is an impurity region formed on the semiconductor substrate.

[0072] In other words, the inter-pixel separation section that separates pixels 31G left and right has, corresponding to the intra-pixel separation sections of pixels 31R and 31B, a portion separated by an impurity region formed in the semiconductor substrate and a portion separated by embedding material in trenches formed in the semiconductor substrate. This makes it possible to make the structure of the inter-pixel separation section of pixel 31G, which is configured as a normal pixel, the same as the structure of the intra-pixel separation section of pixels 31R and 31B, which are configured as pixels for phase difference detection. This makes it possible to match the potential of each pixel.

[0073] Figure 12 shows an eleventh example of the configuration of pixel 31. In Figure 12, parts corresponding to those in Figure 2 are denoted by the same reference numerals, and their explanations are omitted as appropriate.

[0074] In Figure 12, in pixel 31R, which is configured as a pixel for phase difference detection, an inter-element separation section 72 and an impurity separation section 61 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts. In pixel 31B, which is configured as a pixel for phase difference detection, an inter-element separation section 73 and an impurity separation section 62 are formed as in-pixel separation sections that separate the photoelectric conversion section 53-1 and the photoelectric conversion section 53-2, which are formed on a horizontally elongated elliptical microlens 51, into left and right parts.

[0075] In Figure 12, in pixel 31G, which is configured as a normal pixel, a photoelectric conversion section 53 is formed on a circular microlens 51. In addition, an inter-pixel separation section 74 is formed to separate the pixels 31G horizontally. The width (line width) of the inter-pixel separation section 74 is narrower than the width of the inter-element separation section 72 of pixel 31R and the inter-element separation section 73 of pixel 31B when viewed from above. That is, the width of the inter-pixel separation section of pixel 31G, which is configured as a normal pixel, can be made narrower than the width of the intra-pixel separation section of pixels 31R and 31B, which are configured as pixels for phase difference detection. Here, if the inter-element separation sections 72 and 73 are hollowed out to form impurity separation sections 61 and 62, the state of the semiconductor changes and the potential fluctuates. Therefore, the width of the inter-pixel separation section 74, which does not have a hollowed-out shape, is adjusted to match the inter-element separation sections 72 and 73, which have a hollowed-out shape.

[0076] As described above, by adjusting the width of the intra-pixel separation portion of pixels 31R and 31B, which are configured as pixels for phase difference detection, and the width of the inter-pixel separation portion of pixel 31G, which is configured as a normal pixel, according to the state of the semiconductor constituting the semiconductor substrate, the sensitivity of each pixel can be made uniform. Furthermore, in pixels 31R and 31B, by providing impurity separation portions 61 and 62 that separate the central region corresponding to the light collection point, and inter-element separation portions 72 and 73 that separate the portion excluding the central region, it is possible to suppress color mixing caused by light reflected from the intra-pixel separation portion entering other adjacent pixels. For example, as shown in Figures 10 to 12, when light enters the central region of pixel 31R from the direction indicated by arrow A1, since the impurity separation portion 61 is provided in the central region, the reflected light does not enter other pixels, and color mixing of light can be suppressed.

[0077] <Configuration of electronic equipment> Figure 13 shows an example configuration of an embodiment of an electronic device equipped with a light detection device to which the present disclosure is applied. The electronic device 101 is configured as a device having an imaging function, such as a camera, smartphone, tablet terminal, or mobile phone. As shown in Figure 13, the electronic device 101 consists of a photographic lens 121, a light detection unit 122, a signal processing unit 123, a compression / decompression unit 124, a control unit 125, an operation unit 126, a display unit 127, and a storage unit 128.

[0078] The photographic lens 121 focuses (forms an image) light (optical image) from the subject onto the light detection surface of the light detection unit 122. The photographic lens 121 is configured, for example, as a lens unit included in the optical lens barrel, and the optical mechanism (AF mechanism, etc.) is driven by a drive circuit under the control of the control unit 125 to realize functions such as autofocus. The light detection unit 122 detects the light incident from the photographic lens 121 and outputs a signal. The light detection unit 122 is configured, for example, as a light detection device 1 (Figure 1) including a solid-state imaging device such as a CMOS type image sensor.

[0079] The signal processing unit 123, following control from the control unit 125, performs predetermined signal processing (e.g., white balance adjustment processing, color correction processing, etc.) on the signal output from the light detection unit 122 and outputs it as image data to the compression / decompression unit 124. The compression / decompression unit 124, following control from the control unit 125, performs compression encoding processing on the image data output from the signal processing unit 123 using a predetermined method. The compression / decompression unit 124 also performs decompression / decoding processing on the encoded image data supplied by the control unit 125 using a predetermined method, following control from the control unit 125. The predetermined method includes, for example, the JPEG (Joint Photographic Experts Group) method and the MPEG (Moving Picture Experts Group) method.

[0080] The control unit 125 is composed of a microcontroller having, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU controls each part of the electronic device 101 by executing a program stored in the ROM. For example, the control unit 125 performs autofocus based on phase difference information obtained from the light detection unit 122. The operation unit 126 is composed of, for example, buttons, and outputs signals to the control unit 125 according to user input operations. The display unit 127 is composed of, for example, an LCD (Liquid Crystal Display) or an organic EL display, and displays an image corresponding to the image data supplied from the control unit 125. The storage unit 128 is a recording medium such as a portable semiconductor memory, and stores image data compressed and encoded by the compression / decompression unit 124. The storage unit 128 also supplies the stored image data to the control unit 125 according to control from the control unit 125.

[0081] <Examples of use of photodetectors> Figure 13 shows a configuration in which the photodetector 1 to which this disclosure is applied is mounted on an electronic device 101. However, the photodetector 1 to which this disclosure is applied can be used in various cases for sensing light such as visible light, infrared light, ultraviolet light, and X-rays. In other words, the photodetector 1 to which this disclosure is applied can be used not only in the field of appreciation, where images for viewing are taken, but also in devices used in fields such as transportation, home appliances, medical and healthcare, security, beauty, sports, or agriculture.

[0082] Specifically, in the field of appreciation, for example, the light detection device 1 to which this disclosure is applied can be used in devices for capturing images for appreciation, such as digital cameras, smartphones, and mobile phones with camera functions. In the field of traffic, for example, the light detection device 1 to which this disclosure is applied can be used in devices used for traffic, such as in-vehicle sensors that capture images of the front, rear, surroundings, and interior of a vehicle for safe driving such as automatic stopping, or for recognizing the driver's condition, surveillance cameras that monitor moving vehicles and roads, and distance measuring sensors that measure distances between vehicles.

[0083] In the field of home appliances, for example, the photodetector 1 to which this disclosure is applied can be used in devices used in home appliances such as television sets, refrigerators, and air conditioners to capture user gestures and operate the device according to those gestures. In the field of medical and healthcare, for example, the photodetector 1 to which this disclosure is applied can be used in devices used for medical and healthcare purposes, such as endoscopes and devices that perform angiography by receiving infrared light. In the field of security, for example, the photodetector 1 to which this disclosure is applied can be used in devices used for security purposes, such as surveillance cameras for crime prevention and cameras for person authentication.

[0084] In the field of beauty, for example, the light detection device 1 to which this disclosure is applied can be used in devices used for beauty purposes, such as skin measuring devices for photographing skin or microscopes for photographing the scalp. In the field of sports, for example, the light detection device 1 to which this disclosure is applied can be used in devices used for sports purposes, such as action cameras and wearable cameras for sports use. In the field of agriculture, for example, the light detection device 1 to which this disclosure is applied can be used in devices used for agriculture, such as cameras for monitoring the condition of fields and crops.

[0085] The embodiments described herein are not limited to those described above, and various modifications are possible without departing from the spirit of this disclosure. For example, the embodiments described above may be implemented individually or in combination with other embodiments. Furthermore, the effects described herein are merely illustrative and not limiting, and other effects may also occur.

[0086] Furthermore, this disclosure can take the following form.

[0087] (1) The device comprises a pixel array section in which multiple pixels, including a first pixel having multiple photoelectric conversion sections formed on a single microlens, are arranged in a two-dimensional array. The first pixel is provided with a first separation unit that separates the plurality of photoelectric conversion units. The first separation unit is, The portion corresponding to the light-collecting position by the microlens is separated by an impurity region formed on the semiconductor substrate on which the plurality of photoelectric conversion units are formed. The portion excluding the impurity region is separated by embedding a substance in a trench formed in the semiconductor substrate. Light detection device. (2) The first separation unit separates the region including the central part of the first pixel by the impurity region. (1) The light detection device described above. (3) The plurality of pixels include a second pixel in which one photoelectric conversion unit is formed for one microlens, A second separation section is provided to separate the second pixels, The width of the first separation section is narrower than the width of the second separation section when viewed from above. The light detection device described in (1) or (2). (4) The plurality of pixels include a second pixel in which one photoelectric conversion unit is formed for one microlens, The second pixels are provided with filters corresponding to wavelength bands for each color and are arranged in a predetermined pattern. The first pixel has two photoelectric conversion units formed for one microlens, and the filter is provided therein. The light detection device described in (1) or (2). (5) The first pixel is positioned in place of two adjacent pixels in the second pixel arranged in the predetermined pattern. (4) The light detection device described above. (6) The first pixel described above is, A third pixel is provided with a first filter corresponding to the wavelength band of the first color, A fourth pixel is provided with a second filter corresponding to the wavelength band of a second color different from the first color, and including (4) The light detection device described above. (7) The third and fourth pixels are arranged in a predetermined pattern, corresponding to two adjacent pixels in the first direction in the second pixel. (6) The light detection device described above. (8) The third pixel is arranged in a predetermined pattern, corresponding to two pixels adjacent in the first direction in the second pixel, The fourth pixel is arranged in correspondence with two adjacent pixels in a second direction different from the first direction. (6) The light detection device described above. (9) In the third and fourth pixels, the width of the first separation portion differs in a plan view, depending on the wavelength bands that the first and second filters correspond to. (6) The light detection device described above. (10) The width of the first separation portion is adjusted in plan view according to the state of the semiconductor constituting the semiconductor substrate. (4) A light detection device as described in any of (6) to (8). (11) A second separation section is provided to separate the second pixels, The second separation section, corresponding to the first separation section, has a portion separated by impurity regions formed in the semiconductor substrate and a portion separated by embedding material in trenches formed in the semiconductor substrate. (4) A light detection device as described in any of (6) to (8). (12) A second separation section is provided to separate the second pixels, The width of the second separation section is narrower than the width of the first separation section when viewed from above. (4) A light detection device as described in any of (6) to (8). (13) Light detection unit, Based on the phase difference information obtained from the light detection unit, a control unit performs autofocus control. Equipped with, The light detection unit has a pixel array unit in which a plurality of pixels, including a first pixel in which a plurality of photoelectric conversion units are formed for a single microlens, are arranged in a two-dimensional array. The first pixel is provided with a first separation unit that separates the plurality of photoelectric conversion units. The first separation unit is, The portion corresponding to the light-collecting position by the microlens is separated by an impurity region formed on the semiconductor substrate on which the plurality of photoelectric conversion units are formed. The portion excluding the impurity region is separated by embedding a substance in a trench formed in the semiconductor substrate. electronic equipment. [Explanation of Symbols]

[0088] 1 Photodetector, 21 Pixel array unit, 22 Vertical drive unit, 23 Column signal processing unit, 24 Horizontal drive unit, 25 Output unit, 26 Control unit, 31 Pixel, 31R, 31G, 31B Pixel, 51 Microlens, 52R, 52G, 52B Color filters, 53 Photoelectric conversion unit, 53-1, 53-2 Photoelectric conversion unit, 61 Impurity separation unit, 61 Impurity separation unit, 63 Impurity separation unit, 71 Inter-pixel separation unit, 72 Inter-element separation unit, 73 Impurity separation unit, 74 Inter-pixel separation unit, 101 Electronic equipment, 121 Imaging lens, 122 Photodetector, 123 Signal processing unit, 124 Compression / Decompression unit, 125 Control unit, 126 Operation unit, 127 Display unit 128 Storage section

Claims

1. The device comprises a pixel array section in which multiple pixels, including a first pixel having multiple photoelectric conversion sections formed on a single microlens, are arranged in a two-dimensional array. The first pixel is provided with a first separation unit that separates the plurality of photoelectric conversion units. The first separation unit is, The portion corresponding to the light-collecting position by the microlens is separated by an impurity region formed on the semiconductor substrate on which the plurality of photoelectric conversion units are formed. The portion excluding the impurity region is separated by embedding a substance in a trench formed in the semiconductor substrate. Light detection device.

2. The first separation unit separates the region including the central part of the first pixel by the impurity region. The light detection device according to claim 1.

3. The plurality of pixels include a second pixel in which one photoelectric conversion unit is formed for one microlens, A second separation section is provided to separate the second pixels, The width of the first separation section is narrower than the width of the second separation section when viewed from above. The light detection device according to claim 1.

4. The plurality of pixels include a second pixel in which one photoelectric conversion unit is formed for one microlens, The second pixels are provided with filters corresponding to wavelength bands for each color and are arranged in a predetermined pattern. The first pixel has two photoelectric conversion units formed for one microlens, and the filter is provided therein. The light detection device according to claim 1.

5. The first pixel is positioned in place of two adjacent pixels in the second pixel arranged in the predetermined pattern. The light detection device according to claim 4.

6. The first pixel is, A third pixel is provided with a first filter corresponding to the wavelength band of the first color, A fourth pixel is provided with a second filter corresponding to the wavelength band of a second color different from the first color, and including The light detection device according to claim 4.

7. The third and fourth pixels are arranged in a predetermined pattern, corresponding to two adjacent pixels in the first direction in the second pixel. The light detection device according to claim 6.

8. The third pixel is arranged in a predetermined pattern, corresponding to two pixels adjacent in the first direction in the second pixel, The fourth pixel is arranged in a second direction different from the first direction, corresponding to two adjacent pixels. The light detection device according to claim 6.

9. In the third and fourth pixels, the width of the first separation portion differs in a plan view, depending on the wavelength bands that the first and second filters correspond to. The light detection device according to claim 6.

10. The width of the first separation portion is adjusted according to the state of the semiconductor constituting the semiconductor substrate. The light detection device according to claim 4.

11. A second separation section is provided to separate the second pixels, The second separation section, corresponding to the first separation section, has a portion that separates by impurity regions formed in the semiconductor substrate and a portion that separates by embedding material in trenches formed in the semiconductor substrate. The light detection device according to claim 4.

12. A second separation section is provided to separate the second pixels, The width of the second separation section is narrower than the width of the first separation section when viewed from above. The light detection device according to claim 4.

13. Light detection unit, A control unit that performs autofocus control based on the phase difference information obtained from the light detection unit. Equipped with, The light detection unit has a pixel array unit in which a plurality of pixels, including a first pixel in which a plurality of photoelectric conversion units are formed for a single microlens, are arranged in a two-dimensional array. The first pixel is provided with a first separation unit that separates the plurality of photoelectric conversion units. The first separation unit is, The portion corresponding to the light-collecting position by the microlens is separated by an impurity region formed on the semiconductor substrate on which the plurality of photoelectric conversion units are formed. The portion excluding the impurity region is separated by embedding a substance in a trench formed in the semiconductor substrate. electronic equipment.

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