Photoelectric converter, photoelectric converter system, mobile device, equipment, and method for manufacturing a photoelectric converter.

Abstract

This technology provides advantages in improving the characteristics of photoelectric conversion devices. [Solution] A photoelectric conversion device comprising a semiconductor layer having a first main surface and a second main surface and comprising a first photoelectric conversion element and a second photoelectric conversion element adjacent to each other, and an element isolation section disposed to electrically separate the first photoelectric conversion element and the second photoelectric conversion element, wherein a cured product of a curable composition is disposed on the first main surface, and the cured product is provided with a plurality of trenches extending from the surface of the cured product toward the first main surface, the plurality of trenches including a first trench constituting a scattering diffraction structure disposed to overlap the first photoelectric conversion element, and a second trench constituting an isolation structure disposed to overlap the element isolation section.

Description

Technical Field

[0001] The present invention relates to a photoelectric conversion device, a photoelectric conversion system, a moving body, a device, and a method for manufacturing a photoelectric conversion device.

Background Art

[0002] Patent Document 1 discloses a solid-state imaging device in which a fine concavo-convex structure is provided on a light-receiving surface of a semiconductor substrate, and by refracting incident light, the optical path length of the incident light traveling through a photoelectric conversion region is lengthened, thereby improving the photoelectric conversion efficiency. Further, Patent Document 1 shows that this concavo-convex structure is formed using dry etching.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When forming a concavo-convex structure on a semiconductor substrate, plasma damage may occur in the semiconductor substrate due to dry etching, which may cause a decrease in characteristics such as being a cause of dark current noise.

[0005] An object of the present invention is to provide a technique advantageous for improving the characteristics of a photoelectric conversion device.

Means for Solving the Problems

[0006] In view of the above problems, a photoelectric conversion device according to an embodiment of the present invention is a photoelectric conversion device comprising: a semiconductor layer having a first main surface and a second main surface and comprising a first photoelectric conversion element and a second photoelectric conversion element adjacent to each other; and an element isolation section disposed to electrically separate the first photoelectric conversion element and the second photoelectric conversion element, wherein a cured product of a curable composition is disposed on the first main surface, and the cured product is provided with a plurality of trenches extending from the surface of the cured product toward the first main surface, and the plurality of trenches include a first trench constituting a scattering diffraction structure disposed to overlap the first photoelectric conversion element, and a second trench constituting a separation structure disposed to overlap the element isolation section. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide a technology that is advantageous for improving the characteristics of photoelectric conversion devices. [Brief explanation of the drawing]

[0008] [Figure 1] A diagram showing an example configuration of the photoelectric conversion device of this embodiment. [Figure 2] Figure 1 shows an example of the pixel array configuration of the photoelectric converter. [Figure 3] A block diagram showing an example configuration of the photoelectric converter shown in Figure 1. [Figure 4] Figure 1 shows a circuit diagram illustrating an example of the pixel configuration of the photoelectric converter. [Figure 5] Figure 1 illustrates an example of pixel operation in the photoelectric converter. [Figure 6] A cross-sectional view showing an example of the pixel configuration of the photoelectric converter in Figure 1. [Figure 7] A plan view showing an example of the pixel configuration in Figure 6. [Figure 8] A cross-sectional view showing an example of the pixel manufacturing process in Figure 6. [Figure 9] A cross-sectional view showing an example of the pixel manufacturing process in Figure 6. [Figure 10] A cross-sectional view showing an example of the pixel manufacturing process in Figure 6. [Figure 11] A cross-sectional view showing an example of the pixel manufacturing process in Figure 6. [Figure 12] Cross-sectional view showing an example of the manufacturing process of the pixel of FIG. 6. [Figure 13] Cross-sectional view showing a modified example of the pixel of FIG. 6. [Figure 14] Cross-sectional view showing a modified example of the pixel of FIG. 6. [Figure 15] Cross-sectional view showing a modified example of the pixel of FIG. 6. [Figure 16] Functional block diagram of a photoelectric conversion system using the photoelectric conversion device of the present embodiment. [Figure 17] Functional block diagram of a photoelectric conversion system using the photoelectric conversion device of the present embodiment. [Figure 18] Functional block diagram of a photoelectric conversion system using the photoelectric conversion device of the present embodiment. [Figure 19] Functional block diagram of a photoelectric conversion system using the photoelectric conversion device of the present embodiment. [Figure 20] Diagram showing a photoelectric conversion system using the photoelectric conversion device of the present embodiment. [Figure 21] Diagram showing a configuration example of an imprint device used when manufacturing the photoelectric conversion device of the present embodiment.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential for the invention, and the plurality of features may be arbitrarily combined. Furthermore, in the accompanying drawings, the same or similar configurations are denoted by the same reference numerals, and redundant descriptions are omitted.

[0010] First, using FIGS. 1 to 5, an avalanche photodiode (hereinafter sometimes referred to as APD) that can be used as a photoelectric conversion element in the photoelectric conversion device 100 described below will be explained. However, it is not limited to APD, and it goes without saying that other types of photodiodes such as PN diodes and PIN diodes may be used as the photoelectric conversion element in the photoelectric conversion device 100.

[0011] FIG. 1 is a diagram showing a configuration example of the photoelectric conversion device 100. The photoelectric conversion device 100 can be configured by laminating and electrically connecting two substrates, a sensor substrate 11 (hereinafter sometimes simply referred to as substrate 11) and a circuit substrate 21. That is, the photoelectric conversion device 100 may be a stacked device. As will be described later, a semiconductor layer 301 and the like in which a plurality of pixels 101 are arranged are arranged on the substrate 11. A pixel region 12 including a plurality of pixels 101 is arranged on the substrate 11. A circuit region 22 for processing signals detected in the pixel region 12 is arranged on the circuit substrate 21.

[0012] FIG. 2 is a diagram showing an arrangement example of the substrate 11. Pixels 101 each having a photoelectric conversion element 102 including an APD as a photodiode are arranged in a two-dimensional array in the orthographic projection onto the main surface 391 of the substrate 11 to form a pixel region 12. The pixel 101 is typically a pixel for generating an image, but when used in a distance measuring device using the Time of Flight (ToF) method, it does not necessarily have to generate an image. That is, the pixel 101 may be configured to measure the time when light arrives and the amount of light.

[0013] Figure 3 shows an example of the configuration of the circuit board 21. The circuit board 21 includes a signal processing circuit 103 for processing the charge photoelectrically converted by the photoelectric conversion element 102 shown in Figure 2, a readout circuit 112, a control pulse generation circuit 115, a horizontal scanning circuit 111, a signal line 113, a vertical scanning circuit 110, and the like. The signal processing circuit 103 shown in Figure 3 may be arranged to correspond to each of the pixels 101 shown in Figure 2. In that case, the pixels 101 (photoelectric conversion element 102) and the signal processing circuit 103 may be electrically connected via connecting wiring provided for each pixel 101.

[0014] The vertical scanning circuit 110 receives control pulses supplied from the control pulse generation circuit 115 and supplies control pulses to each pixel 101 via the drive line 116. Logic circuits such as shift registers and address decoders may be used in the vertical scanning circuit 110.

[0015] The signal output from pixel 101 is processed by signal processing circuit 103. The signal processing circuit 103 may be equipped with a counter and memory. The memory may store the count value counted by the counter as a digital value.

[0016] The horizontal scanning circuit 111 inputs control pulses to the signal processing circuit 103 to sequentially select each column in order to read a signal from the memory of the signal processing circuit 103 corresponding to each pixel 101 in which a digital signal is held. For the selected column, a signal is output from the signal processing circuit 103 corresponding to the pixel 101 selected by the vertical scanning circuit 110 to the signal line 113. The signal output to the signal line 113 is output via the output circuit 114 to an external recording unit or signal processing unit of the photoelectric converter 100.

[0017] The arrangement of pixels 101 in the pixel region 12 shown in Figure 2 is not limited to a two-dimensional array. The pixels 101 may be arranged in a one-dimensional manner. The function of the signal processing circuit 103 does not necessarily need to be provided for every pixel 101 (photoelectric conversion element 102). For example, one signal processing circuit 103 may be shared by two or more pixels 101 (photoelectric conversion elements 102), and signal processing may be performed sequentially.

[0018] As shown in Figures 2 and 3, in the orthogonal projection onto the pixel region 12, multiple signal processing circuits 103 may be arranged in the region overlapping the pixel region 12. In addition, a vertical scanning circuit 110, a horizontal scanning circuit 111, a readout circuit 112, an output circuit 114, a control pulse generation circuit 115, etc., may be arranged so as to overlap between the edge of the substrate 11 and the edge of the pixel region 12. In other words, the substrate 11 has a pixel region 12 and a non-pixel region (peripheral region) arranged around the pixel region 12. In that case, the vertical scanning circuit 110, the horizontal scanning circuit 111, the readout circuit 112, the output circuit 114, and the control pulse generation circuit 115 may be arranged in the region overlapping the non-pixel region.

[0019] Figure 4 is an example of a block diagram including an equivalent circuit, focusing on a single pixel 101 (photoelectric conversion element 102). In Figure 4, the photoelectric conversion element 102, including the APD201, is provided on the substrate 11, while the other components are provided on the circuit board 21.

[0020] The APD201 generates charge pairs corresponding to incident light through photoelectric conversion. A potential VL is supplied to the anode of the APD201. A potential VH, higher than the potential VL supplied to the anode, is supplied to the cathode of the APD201. A reverse bias voltage is supplied to the anode and cathode such that the APD201 performs avalanche multiplication. By supplying such a reverse bias voltage, the charge generated by the incident light undergoes avalanche multiplication, and an avalanche current is generated.

[0021] When a reverse bias voltage is supplied to the APD201, there are two modes of operation: Geiger mode, where the potential difference (voltage) between the anode and cathode is greater than the breakdown voltage, and linear mode, where the potential difference between the anode and cathode is near or below the breakdown voltage. An APD operating in Geiger mode is called a Single Photon Avalanche Diode (SPAD). For example, the potential VL is -30V and the potential VH is 1V. The APD201 may be operated in linear mode or Geiger mode.

[0022] The quench element 202 is connected between the power supply that provides the potential VH and the APD201. The quench element 202 functions as a load circuit (quench circuit) during signal multiplication by avalanche multiplication, suppressing the voltage supplied to the APD201 and thereby suppressing avalanche multiplication (quench operation). In addition, the quench element 202 also works to restore the voltage supplied to the APD201 to the voltage (VH-VL) by flowing the current that compensates for the voltage drop caused by the quench operation (recharge operation).

[0023] The signal processing circuit 103 may include a waveform shaping circuit 210, a counter circuit 211, and a selection circuit 212. In this specification, the signal processing circuit 103 may have any one of the waveform shaping circuit 210, the counter circuit 211, or the selection circuit 212.

[0024] The waveform shaping circuit 210 shapes the cathode potential change of the APD201 obtained during photon detection and outputs a pulse signal. For example, an inverter circuit can be used as the waveform shaping circuit 210. In the configuration shown in Figure 4, an example is shown in which one inverter is used as the waveform shaping circuit 210. However, it is not limited to this, and a circuit in which multiple inverters are connected in series may be used as the waveform shaping circuit 210, or other circuits that have a waveform shaping effect may be used.

[0025] The counter circuit 211 counts the pulse signals output from the waveform shaping circuit 210 and holds the count value. Furthermore, when a control pulse pRES is supplied from the vertical scanning circuit 110 shown in Figure 3 via a drive line 213 which corresponds to a part of the drive line 116 shown in Figure 3, the signal held in the counter circuit 211 is reset.

[0026] The selection circuit 212 receives a control pulse pSEL from the vertical scanning circuit 110 via a drive line 214, which corresponds to a portion of the drive line 116 shown in Figure 3, to switch the electrical connection or disconnection between the counter circuit 211 and the signal line 113. The selection circuit 212 may include, for example, a buffer circuit for outputting a signal.

[0027] The electrical connection may be switchable by placing a switching element such as a transistor between the quench element 202 and the APD201, or between the photoelectric conversion element 102 and the signal processing circuit 103. Similarly, the supply of potential VH or potential VL to the photoelectric conversion element 102 may be electrically switchable using a switching element such as a transistor.

[0028] In this embodiment, a configuration is shown in which a counter circuit 211 is provided in the signal processing circuit 103. However, the configuration is not limited to this, and the photoelectric converter 100 may be configured to acquire pulse detection timing using a time-to-digital conversion circuit (TDC) and memory instead of the counter circuit 211. In that case, the generation timing of the pulse signal output from the waveform shaping circuit 210 is converted into a digital signal by the TDC. The TDC is supplied with a control pulse pREF (reference signal) from the vertical scanning circuit 110 via the drive line 116 to measure the timing of the pulse signal. The TDC uses the control pulse pREF as a reference and acquires the signal as a digital signal when the input timing of the signal output from each pixel 101 via the waveform shaping circuit 210 is considered as a relative time.

[0029] Furthermore, while Figure 4 shows an example where the quench element 202, waveform shaping circuit 210, counter circuit 211, and selection circuit 212 are arranged on a single circuit board 21, the configuration is not limited to this. For example, the quench element 202 and waveform shaping circuit 210 may be arranged on one board, and the counter circuit 211 and selection circuit 212 may be arranged on another board, with these boards stacked on top of each other.

[0030] Figures 5(a) and 5(b) schematically illustrate the relationship between the operation of the APD201 and the output signal. Figure 5(a) is an excerpt of the APD201, quench element 202, and waveform shaping circuit 210 shown in Figure 4. Here, the input side of the waveform shaping circuit 210 is denoted as nodeA and the output side as nodeB. Figure 5(b) shows the waveform changes at nodeA and nodeB.

[0031] From time t0 to time t1, a potential difference (voltage) of potential VH - potential VL is applied to APD201. When a photon is incident on APD201 at time t1, avalanche multiplication occurs in APD201, an avalanche multiplication current flows through the quench element 202, and the potential of nodeA drops. As the voltage drop becomes larger and the potential difference applied to APD201 decreases, the avalanche multiplication of APD201 stops, as shown at time t2, and the potential level of nodeA stops dropping below a certain value. Subsequently, between time t2 and time t3, a current flows through nodeA from potential VL to compensate for the voltage drop, and at time t3, nodeA settles to its original potential level. At this time, any portion of the output waveform at nodeA that exceeds a certain threshold is waveform-shaped by the waveform shaping circuit 210 and output as a signal to nodeB.

[0032] The arrangement of the signal line 113, the read circuit 112, and the output circuit 114 is not limited to the configuration shown in Figure 3. For example, the signal line 113 may extend in the row direction (horizontal direction in Figure 3), and the read circuit 112 may be located at the end of the signal line 113.

[0033] Next, the configuration of the pixels 101 arranged in the photoelectric converter 100 of this embodiment will be described in detail. Figure 6 is a cross-sectional view showing the configuration of the pixels 101 arranged in the pixel region 12. Figures 7(a) and 7(b) are plan views showing the configuration of the pixels 101. Figure 6 is a cross-sectional view between A and A' shown in Figure 7(a). Figure 7(a) is a plan view of the main surface 391 of the semiconductor layer 301 shown in Figure 6. Figure 7(b) is a plan view focusing on the trench 351 provided in the cured product 350 of the curable composition arranged on the main surface 392 of the semiconductor layer 301. The photoelectric converter 100 shown in Figures 6, 7(a), and 7(b) has the configuration of a so-called back-illuminated sensor.

[0034] The photoelectric converter 100 has a plurality of pixels 101 arranged on a substrate 11 made of semiconductor material. Each of the plurality of pixels 101 has an APD201 formed on a semiconductor layer 301 provided on the substrate 11 as a photoelectric conversion element 102. It can also be said that the semiconductor layer 301 having main surfaces 391 and 392 has an APD201 as a photoelectric conversion element 102. Each pixel 101 (APD201) is separated by an element isolation section 324 that extends from the main surface 391 to the main surface 392 of the semiconductor layer 301, which is arranged to electrically isolate adjacent APD201s. Although not shown in Figure 6, the photoelectric converter 100 further includes a semiconductor layer of a circuit board 21 separate from the semiconductor layer 301 (substrate 11), which is arranged facing the main surface 391 of the semiconductor layer 301 (substrate 11) via an insulating layer 341, a protective layer 342, an interlayer insulating layer 343, etc. The semiconductor layer of the circuit board 21 may contain elements such as transistors for operating the photodiode APD201. Here, an example is shown in which APD201 is used as the photoelectric conversion element 102, but as mentioned above, other types of photodiodes such as PN diodes or PIN diodes may be used as the photoelectric conversion element 102 for each of the multiple pixels 101.

[0035] Each pixel 101 comprises semiconductor regions 311, 313, 315, and 316 of the same conductivity type. Furthermore, pixel 101 includes semiconductor regions 312, 314, 317, and 319 of the opposite conductivity type to semiconductor regions 311, 313, 315, and 316. For example, semiconductor regions 311, 313, 315, and 316 may be N-type semiconductor regions, and semiconductor regions 312, 314, 317, and 319 may be P-type semiconductor regions. Silicon is an example of a semiconductor material used for the substrate 11 (semiconductor layer 301). Therefore, semiconductor regions 311-317 and 319 may be regions in which impurities corresponding to the conductivity type have been implanted into silicon. For example, semiconductor regions 311, 312, 313, 314, 315, 317, and 319 may be formed in the N-type semiconductor layer 301 (semiconductor region 316) using an ion implantation method or the like.

[0036] In the configuration shown in Figure 6, light is incident from the top of the figure. That is, in semiconductor layer 301, the main surface 392 is the light incident surface. An N-type semiconductor region 311 is located near the main surface 391 of semiconductor layer 301, and an N-type semiconductor region 313 is located around it. In the orthogonal projection of semiconductor layer 301 onto the main surface 391, a P-type semiconductor region 312 is located at a position overlapping with semiconductor regions 311 and 313. Hereafter, the expression "overlapping semiconductor regions" refers to the overlap of each semiconductor region in the orthogonal projection of semiconductor layer 301 onto the main surface 392. The expression "overlapping" may also be used in other configurations. An N-type semiconductor region 315 is located at a position overlapping with semiconductor region 312, and an N-type semiconductor region 316 is located around it.

[0037] Semiconductor region 311 is a region with a higher N-type impurity concentration than semiconductor regions 313 and 315. A PN junction is formed between the P-type semiconductor region 312 and the N-type semiconductor region 311. By lowering the impurity concentration of semiconductor region 312 to that of semiconductor region 311, the application of a reverse bias causes all areas of semiconductor region 312 that overlap with the center of semiconductor region 311 to become a depletion layer region. In this case, the potential difference between semiconductor region 311 and semiconductor region 312 becomes greater than the potential difference between semiconductor region 312 and semiconductor region 315. Furthermore, this depletion layer region extends to a portion of semiconductor region 311, inducing a strong electric field in the depletion layer region. This strong electric field induces avalanche multiplication in the depletion layer region that extends to a portion of semiconductor region 311, and a current based on the amplified charge is output as a signal charge. When light incident on pixel 101 is converted into photoelectricity, and avalanche multiplication is induced in this depletion layer region (avalanche multiplication region), the generated N-type charge is collected in semiconductor region 311.

[0038] Semiconductor region 311 is connected to wiring pattern 331 via contact plug 330. Semiconductor region 312 is connected to wiring pattern 331 via semiconductor regions 317, 319 and contact plug 330. By making the impurity concentration of semiconductor region 319 higher than that of semiconductor region 317, the contact resistance between semiconductor region 319 and contact plug 330 is reduced. Here, the wiring pattern 331 to which semiconductor region 311 is connected and the wiring pattern 331 to which semiconductor region 312 is connected are different wiring patterns.

[0039] In Figure 6, semiconductor region 313 and semiconductor region 315 are formed to be approximately the same size in the planar direction, but the size of each semiconductor region is not limited to this. For example, semiconductor region 315 may be formed to be larger than semiconductor region 313, allowing charge to be collected in semiconductor region 311 from a wider area. Also, semiconductor region 313 may be a P-type semiconductor region instead of an N-type. In this case, the impurity concentration of semiconductor region 313 is set lower than the impurity concentration of semiconductor region 312. This is because if the impurity concentration of semiconductor region 313 is too high, the area between semiconductor region 313 and semiconductor region 311 may become an avalanche multiplication region, potentially increasing the Dark Count Rate (DCR).

[0040] As described above, each pixel 101 (APD201) is separated by an element isolation section 324. Insulators 325 and 326 are embedded in the element isolation section 324. The insulators 325 and 326 may completely embed the element isolation section 324, or there may be some gaps. Materials such as silicon oxide, silicon nitride, or silicon oxynitride may be used for the insulators 325 and 326. The insulators 325 and 326 may be composed of a single material, or they may have a multilayer structure using multiple materials.

[0041] As shown in Figure 6, particles of metal oxides such as titanium oxide may be added to the insulator 325 embedded in a part 324a of the element isolation portion 324 on the main surface 391 side of the semiconductor layer 301. Alternatively, pigments or dyes such as black may be added to the insulator 325. Furthermore, metals or the like may be embedded in the insulator 325. As described above, avalanche multiplication is induced in the depletion layer region extending from the semiconductor region 312 to the semiconductor region 311. In this case, even if avalanche emission occurs, the light is reflected or absorbed by the insulator 325, and crosstalk, where the light is detected by a pixel 101 (APD201) adjacent to the pixel 101 (APD201) that emitted light, can be suppressed. Furthermore, adding metal oxide particles or embedding metal to the insulator 325, rather than adding a colored material, may improve the sensitivity of the pixel 101 (APD201) because light incident obliquely on the pixel 101 is reflected by the insulator 325 (or the embedded metal).

[0042] The insulator 325 may be arranged, for example, from the main surface 391 of the semiconductor layer 301 up to the height where the semiconductor region 312 is located. For example, the semiconductor layer 301 is etched from the side of the main surface 391 to form a trench that will become part 324a of the element isolation portion 324. Then, this trench is filled with the insulator 325. Alternatively, the semiconductor layer 301 is etched from the side of the main surface 392 to form a trench that will become part 324b of the element isolation portion 324, and this trench is filled with the insulator 326. By using such a process, it is possible to form the element isolation portion 324. However, it is not limited to this, and the element isolation portion 324 may have any configuration as long as it can achieve the desired electrical isolation between pixels 101 (APD201). For example, the insulator 325 and the insulator 326 may be formed using the same material or may have the same configuration. Furthermore, in the configuration shown in Figure 6, for example, the element isolation portion 324 is shown to be formed using at least two etching processes. However, it is not limited to this, and the element isolation portion 324 may also be configured in which a trench is formed by a single etching process and an insulator 325 or insulator 326 is embedded.

[0043] In the configuration shown in Figures 6, 7(a), and 7(b), a functional layer 321 including a pinning layer, a planarization layer 322, and a microlens 323 are arranged on the main surface 392 of the semiconductor layer 301. A cured product 350 of a curable composition is also arranged between the functional layer 321 and the planarization layer 322. By arranging the functional layer 321 including the pinning layer in contact with the main surface 392 of the semiconductor layer 301, holes are induced near the main surface 392 of the semiconductor layer 301, and dark current is suppressed. The functional layer 321 including the pinning layer can be made of materials such as hafnium oxide, zirconium oxide, aluminum oxide, titanium oxide, or tantalum oxide. The functional layer 321 may be a single-layer structure using one of these materials, or it may be a multilayer structure using multiple materials. In other words, the functional layer 321 may have a multilayer structure and function as an anti-reflective layer. Thus, the functional layer 321 may have functions such as suppressing dark current and preventing reflections.

[0044] The planarization layer 322, placed between the cured material 350 and the microlens 323, is a layer for flattening the surface on which the microlens 323 is placed. Trench 351 is provided on the surface 352 of the cured material 350, as shown in Figure 6, and material 353 is embedded in it. The planarization layer 322 flattens any irregularities that may occur as a result of this configuration. The planarization layer 322 may be formed from an inorganic material or from an organic material such as a resin. Furthermore, the planarization layer 322 may have a laminated structure in which multiple material layers are stacked.

[0045] The microlens 323 may be formed using a resin material or the like. A color filter may be placed between the functional layer 321 and the cured product 350, between the cured product 350 and the planarization layer 322, or between the planarization layer 322 and the microlens 323. Alternatively, the planarization layer 322 may function as a color filter.

[0046] The cured product 350 of the curable composition is provided with a plurality of trenches 351 extending from the surface 352 of the cured product 350 toward the main surface 392 of the semiconductor layer 301. As shown in Figures 6 and 7(b), the plurality of trenches 351 include trenches 351a that constitute a scattering diffraction structure, which are arranged so as to overlap at least a portion of the APD201, which is the photoelectric conversion element 102, and trenches 351b that constitute a separation structure, which are arranged so as to overlap the element separation portion 324. The trenches 351 may be filled with a material 353 that has a refractive index different from that of the cured product 350. The material 353 embedded in the trenches 351 may completely fill the trenches 351, or there may be voids in some parts. The material 353 embedded in the trenches 351 may be silicon oxide or silicon nitride, an organic material such as a resin may be used, or a metal may be used. However, it is not limited to this, and the material 353 does not have to be embedded in the trench 351 provided in the cured product 350 of the curable composition (the trench 351 may be a void). The trench 351 may be formed, for example, to a depth of about 20 nm to 200 nm from the surface 352 of the cured product 350 of the curable composition.

[0047] Trench 351a, which constitutes the scattering diffraction structure, is arranged so that at least a portion of it overlaps with APD201, and the light incident on pixel 101 is scattered by the scattering diffraction structure. As a result, the incident light travels diagonally within pixel 101, ensuring an optical path length greater than the thickness of the semiconductor layer 301, and thus increasing the photoelectric conversion efficiency. Furthermore, the increased optical path length makes it possible to photoelectrically convert light of longer wavelengths than when the scattering diffraction structure is not provided. In order to sufficiently increase the diffraction of light incident on pixel 101, the depth of trench 351a may be greater than the width of trench 351a. For example, the depth of trench 351a may be about 200 nm, and the width of trench 351a may be about 100 nm to 150 nm. Furthermore, for example, the inner dimensions of the rectangular unit structures of the trenches 351a constituting the scattering diffraction structure, as shown in Figure 7(b), (the spacing between adjacent trenches 351a) may be approximately 250 nm to 350 nm. Figure 7(b) shows an example in which square unit structures are periodically arranged as the scattering diffraction structure, but it is not limited to this, and rectangular or rhombus shapes may also be used. Moreover, the unit structures of the scattering diffraction structure are not limited to rectangles, and any appropriate shape such as triangles or polygons with pentagons or more may be used.

[0048] Furthermore, trenches 351b constituting the separation structure are arranged so as to overlap the element separation section 324. This can suppress crosstalk, in which light incident obliquely on a pixel 101 is incident on an adjacent pixel 101 via the cured product 350 of the curable composition. The trenches 351b may be arranged so as to surround each pixel 101, as shown in Figure 7(b). Also, as shown in Figure 7(b), the trenches 351a and trenches 351b may be arranged independently (not continuous).

[0049] Next, the manufacturing method of the photoelectric converter 100 of this embodiment will be described. Since the APDs formed on the semiconductor layer 301 can be formed using known semiconductor processes, here we will focus on the trenches 351 formed in the cured product 350 of the curable composition. Before describing the specific manufacturing method, first we will describe the imprint process used to form the trenches 351 in the cured product 350 of the curable composition. Figure 21 schematically shows one example configuration of the imprint apparatus NIL. The imprint apparatus NIL is a device that transfers the pattern of the mold M to the curable composition IM on the substrate S. As the curable composition IM, a composition that hardens when hardening energy is applied (sometimes called an unhardened resin) is used. As hardening energy, electromagnetic waves, heat, etc., are used. As electromagnetic waves, for example, light such as infrared rays, visible light, ultraviolet rays, etc., whose wavelength is selected from the range of 10 nm or more and 1 mm or less. The curable composition IM may also be understood as a composition that hardens by irradiation with light or by heating. Of these, the photocurable composition that hardens with light contains at least a polymerizable compound and a photopolymerization initiator, and may optionally contain a non-polymerizable compound or a solvent. The non-polymerizable compound may be at least one selected from the group consisting of sensitizers, hydrogen donors, internal release agents, surfactants, antioxidants, polymer components, etc. The curable composition IM can be applied to a substrate in a film form by a spin coater or a slit coater. The curable composition IM may also be applied to a substrate by a liquid spray head in the form of droplets, or in the form of islands or films formed by multiple droplets being connected. The viscosity (viscosity at 25°C) of the curable composition IM is, for example, 1 mPa·s or more and 100 mPa·s or less.

[0050] The imprint apparatus NIL may include a substrate stage SS including a substrate chuck SC for holding a substrate S, and a substrate drive mechanism SSD for driving the substrate stage SS. The imprint apparatus NIL may also include a mold drive mechanism MD for holding and driving a mold M. The substrate drive mechanism SD and the mold drive mechanism MD constitute a relative drive mechanism that drives at least one of the substrate SD and the mold MD so that the relative position of the substrate S and the mold M is adjusted. The adjustment of the relative position by the relative drive mechanism includes driving for contact of the mold M with the curable composition IM on the substrate S, and for separation of the mold M from the cured product of the curable composition IM. The adjustment of the relative position by the relative drive mechanism also includes alignment of the substrate S (shot area) and the mold M (pattern area PR). The substrate drive mechanism SSD may be configured to drive the substrate S around a plurality of axes (e.g., three axes: X, Y, and θZ; and further, for example, six axes: X, Y, Z, θX, θY, and θZ). The imprint apparatus NIL may include a mold deformation mechanism DM for deforming the two-dimensional shape of the pattern region PR of the mold M. The mold deformation mechanism DM can deform the pattern region PR of the mold M by, for example, applying force to the side of the mold M. The mold drive mechanism MD may be configured to drive the mold M along multiple axes (e.g., three axes: Z-axis, θX-axis, θY-axis, or even six axes: X-axis, Y-axis, Z-axis, θX-axis, θY-axis, θZ-axis). The imprint apparatus NIL may also include a pressure controller CPC that controls the three-dimensional shape of the pattern region PR of the mold M by adjusting the pressure in a sealed space SP formed on the back of the mold M. By adjusting the pressure in the sealed space SP, the pressure controller CPC can deform the pattern region PR of the mold M into a downward convex shape or flatten it.

[0051] The imprint apparatus NIL may include one or more alignment scopes AS for measuring the alignment error between the shot area of ​​the substrate S and the pattern area PR of the mold M. The imprint apparatus NIL may include a curing unit CU for curing the curable composition IM by irradiating it with curing energy through the mold M to form a cured film (cured product). The imprint apparatus NIL may include a dispenser DP for applying or placing the curable composition IM onto the substrate S. The imprint apparatus NIL may include an off-axis scope OAS for detecting the position of alignment marks on the substrate S. The imprint apparatus NIL may include a control unit CNT for controlling each component of the imprint apparatus NIL. The control unit CNT may be an information processing device consisting of, for example, a Programmable Logic Device (PLD) such as a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a computer with a program installed, or a combination of all or some of these.

[0052] The following describes a method for forming trenches 351 in a cured product 350 of a curable composition using an imprint process. First, a semiconductor layer 301 with APD201 and the like formed on it is prepared, as shown in Figure 8. Next, in the imprint apparatus NIL, a step is performed in which the curable composition 360 (curable composition IM in Figure 21) is placed by the dispenser DP so as to cover the main surface 392 (and functional layer 321, if present) of the semiconductor layer 301. A mold 361 (mold M in Figure 15) is also prepared.

[0053] Once the curable composition 360 is placed, a step is performed to bring the mold 361 into contact with the curable composition 360, as shown in Figure 9. Next, as shown in Figure 10, with the curable composition 360 and the mold 361 in contact, a step is performed to cure the curable composition 360 with the curing unit CU. This forms a cured product 350 of the curable composition 360. After the cured product 350 is formed, a step is performed to separate the mold 361 from the cured product 350, as shown in Figure 11. The process, which includes the steps of placing the curable composition 360 on the semiconductor layer 301, bringing the mold 361 into contact with the curable composition 360, curing the curable composition 360, and separating the mold 361 from the cured product 350 of the curable composition 360, may be called an imprint process. Thus, in this embodiment, an imprint process is used to place a cured product 350 with trenches 351 on the semiconductor layer 301.

[0054] After forming a cured product 350 with trenches 351, material 353 is embedded in the trenches 351, as shown in Figure 12. The material 353 embedded in the trenches 351 can be formed by an appropriate method depending on the material 353 used, such as chemical vapor deposition (CVD), sputtering, or spin-on-glass (SOG). On the other hand, the cured product 350 (curable composition 360) can be an acrylic resin or a phenolic resin. Therefore, the material 353 can be embedded in the trenches 351 using a relatively low-temperature process. For example, a material film containing silicon oxide or the like may be formed using the CVD or SOG method to cover the surface 352 of the cured product 350, and then the material 353 may be formed by removing the unnecessary parts using the etch-back method or polishing method. After the material 353 is embedded in the trenches 351, a planarization layer 322 is formed to cover the cured product 350, and then a microlens 323 is formed so as to overlap the photoelectric conversion element 102 (APD201). Here, an example is shown in which the planarization layer 322 is formed after the material 353 is embedded in the trench 351, but the method is not limited to this, and the material 353 embedded in the trench 351 may be formed integrally with at least a portion of the planarization layer 322. For example, the planarization layer 322 may be formed together with the material 353 embedded in the trench 351 by forming a material film that covers the surface 352 of the cured product 350 using a CVD method or SOG method, and then polishing the surface. Alternatively, the material 353 embedded in the trench 351 and a portion of the planarization layer 322 may be formed by such a process, and then a further film deposition process may be performed to form the planarization layer 322. Including these processes, a photoelectric conversion device 100 as shown in Figure 6 can be manufactured.

[0055] When a scattering diffraction structure is realized by forming trenches in the semiconductor layer 301, plasma damage may occur during the etching process to form the trenches in the semiconductor layer 301, potentially degrading the characteristics of the photoelectric converter, such as increasing dark current noise. Furthermore, additional processes to suppress plasma damage may be required, increasing the manufacturing process and potentially raising costs. In contrast, in this embodiment, trenches 351a, which function as a scattering diffraction structure, are provided in the cured product 350 of the curable composition disposed on the semiconductor layer 301. This allows for the formation of a scattering diffraction structure on the photoelectric converter element 102 (APD201) without generating plasma damage to the semiconductor layer 301. As a result, improvements in the characteristics of the photoelectric converter 100 can be achieved more easily than when trenches are formed in the semiconductor layer 301.

[0056] The scattering diffraction structure diffracts light due to the difference in refractive index between the cured material 350 and the material 353 embedded in the trench 351a. Therefore, the refractive indices of the cured material 350 and the material 353 embedded in the trench 351 must be different. For example, the refractive index of the cured material 350 may be greater than that of the material 353 embedded in the trench 351. When a silicon oxide-based material (for example, silicon oxide has a refractive index of about 1.46) is used as the material 353 embedded in the trench 351a, the cured material 350 may have a refractive index of, for example, about 1.5 to 2.0. Metal oxide particles may be added to the cured material 350 to improve its refractive index. For example, the cured material 350 may be an acrylic resin or phenolic resin to which titanium oxide (titania) or zirconium oxide (zirconia) has been added. The cured material 350 may be a photocurable composition or a thermosetting composition. Furthermore, the cured material 350 may have a lower refractive index than the material 353 embedded in the trench 351. In that case, a dielectric material such as aluminum oxide, lanthanum oxide, or silicon nitride may be embedded as the material 353 in the trench 351a provided in the cured material 350. Alternatively, for example, regardless of the refractive index of the cured material 350, a metal such as aluminum may be embedded as the material 353 in the trench 351a provided in the cured material 350.

[0057] When the imprint process described above is used, in the step of bringing the mold 361 into contact with the curable composition 360, as shown in Figure 9, the curable composition 360 is present between the protruding portion of the mold 361 and the semiconductor layer 301 (functional layer 321). Therefore, as shown in Figure 6, a portion of the cured material 350 is placed between the bottom surface of the trench 351 and the main surface 392 of the semiconductor layer 301 (or the functional layer 321, if present). For example, the thickness and refractive index of each layer, such as the material 353 embedded in the trench 351, the cured material 350 between the bottom surface of the trench 351a and the functional layer 321, and the functional layer 321, can be adjusted to appropriate values. As a result, each of these layers may function as an anti-reflective layer or the like.

[0058] Furthermore, for example, as shown in Figure 13, the trench 351 may extend to the functional layer 321. The configuration shown in Figure 13 can be achieved by performing an additional etching process after forming the trench 351 using an imprint process and before filling the trench 351 with material 353. In this etching process, the functional layer 321 may function as an etching stop layer. This makes it possible to suppress variations in the depth of the trench 351 in each pixel 101 in a photoelectric converter 100 in which multiple pixels 101 are arranged.

[0059] Furthermore, as shown in Figure 14, for example, the trench 351b may extend to the element isolation portion 324. This can further suppress crosstalk between pixels 101. For example, after forming the trench 351, a resist pattern may be placed to cover the trench 351a, and the trench 351b may be further etched to form the trench 351b. Alternatively, for example, in the mold 361, the portion for forming the trench 351b may protrude more than the portion for forming the trench 351a, thereby forming the trench 351 in the cured material 350 such that the depth of the trench 351b is greater than that of the trench 351a. Then, before filling the trench 351 with material 353, an additional etching process may be performed to form the trench 351b so that it extends to the element isolation portion 324.

[0060] Furthermore, as shown in Figure 15, for example, the surface 352 of the cured material 350 may have a recess 354 that is curved and recessed toward the main surface 392 of the semiconductor layer 301, and the trenches 351a constituting the scattering diffraction structure may be arranged in the recess 354. The scattering diffraction structure can also be said to include a lattice portion 355 formed by the recess 354 provided on the surface 352 of the cured material 350 that is curved and recessed toward the main surface 392 of the semiconductor layer 301, and the trenches 351a extending from the recess 354 toward the main surface 392 of the semiconductor layer 301. If the refractive index of the cured material 350 is greater than that of the material 353 embedded in the trenches 351, the recess 354 functions as a concave lens. As a result, the light incident on the pixel 101 has a larger component toward the element isolation portion 324 and is reflected by the surface of the element isolation portion 324. As a result, a longer optical path length can be secured than when the recess 354 is not provided. The positions of the bottom surfaces of trenches 351a and 351b can be the respective positions described above.

[0061] The following describes an example of an application of the photoelectric converter 100 in which the aforementioned pixels 101 are arranged.

[0062] Figure 16 is a block diagram illustrating the schematic configuration of a photoelectric conversion system. The photoelectric conversion device 100 described above is applicable to various photoelectric conversion systems. Examples of applicable photoelectric conversion systems include digital still cameras, digital camcorders, surveillance cameras, photocopiers, fax machines, mobile phones, in-vehicle cameras, and observation satellites. A camera module equipped with an optical system such as a lens and an imaging device is also included in the photoelectric conversion system. Figure 16 shows a block diagram of a digital still camera as an example of these.

[0063] The photoelectric conversion system 1000 illustrated in Figure 16 includes an imaging device 1004, which is an example of a photoelectric conversion device; a lens 1002 that forms an optical image of a subject onto the imaging device 1004; an aperture 1003 for varying the amount of light passing through the lens 1002; and a barrier 1001 for protecting the lens 1002. The lens 1002 and aperture 1003 are an optical system (optical device) that focuses light onto the imaging device 1004. The imaging device 1004 is the aforementioned photoelectric conversion device 100 (imaging device) that converts the optical image formed by the lens 1002 into an electrical signal.

[0064] The photoelectric conversion system 1000 also includes a signal processing unit 1007, which is an image generation unit that generates an image by processing the output signal output by the imaging device 1004. The signal processing unit 1007 functions as a processing device that performs various corrections and compressions as needed and outputs image data. The signal processing unit 1007 may be formed on the semiconductor substrate on which the imaging device 1004 is provided, or it may be formed on a semiconductor substrate separate from the imaging device 1004. Alternatively, the imaging device 1004 and the signal processing unit 1007 may be formed on the same semiconductor substrate.

[0065] The photoelectric conversion system 1000 further includes a memory unit 1010 for temporarily storing image data, and an external interface unit (external I / F unit) 1013 for communicating with an external computer or the like. Furthermore, the photoelectric conversion system 1000 includes a recording medium 1012 such as a semiconductor memory for recording or reading imaging data, and a recording medium control interface unit (recording medium control I / F unit) 1011 for recording or reading data from the recording medium 1012. The recording medium control I / F unit 1011 and the recording medium 1012 can constitute part of a storage device. The recording medium 1012 may be built into the photoelectric conversion system 1000 or it may be detachable.

[0066] Furthermore, the photoelectric conversion system 1000 includes an overall control / calculation unit 1009 that controls various calculations and the entire digital still camera, and a timing generation unit 1008 that outputs various timing signals to the imaging device 1004 and the signal processing unit 1007. The overall control / calculation unit 1009 and the timing generation unit 1008 can constitute part of a control device for controlling the operation of the photoelectric conversion system 1000. Here, timing signals and the like may be input from an external source, and the photoelectric conversion system 1000 only needs to include at least an imaging device 1004 and a signal processing unit 1007 that processes output signals output from the imaging device 1004.

[0067] The imaging device 1004 outputs an imaging signal to the signal processing unit 1007. The signal processing unit 1007 performs predetermined signal processing on the imaging signal output from the imaging device 1004 and outputs image data. The signal processing unit 1007 generates an image using the imaging signal. Although not shown in Figure 16, a display device such as a display for displaying the generated image may be provided in the photoelectric conversion system 1000. Thus, according to this embodiment, a photoelectric conversion system 1000 to which the above-described photoelectric conversion device 100 (imaging device) is applied can be realized.

[0068] Figures 17(a) and 17(b) show the configuration of the photoelectric conversion system 1300 and the mobile body 1301. Figure 17(a) shows an example of a photoelectric conversion system related to an in-vehicle camera. The photoelectric conversion system 1300 has an imaging device 1310. The imaging device 1310 is the photoelectric conversion system 100 (imaging device) described above. The photoelectric conversion system 1300 has an image processing unit 1312 that performs image processing on a plurality of image data acquired by the imaging device 1310. The photoelectric conversion system 1300 also has a distance acquisition unit 1316 that calculates the distance to an object, and a collision determination unit 1318 that determines whether or not there is a possibility of collision based on the calculated distance. Here, the distance acquisition unit 1316 may acquire distance information to an object using the Time of Flight (ToF) method, or it may acquire distance information using parallax information, etc. That is, distance information is information related to parallax, defocus amount, distance to an object, etc. The collision detection unit 1318 may use any of this distance information to determine the possibility of a collision. The distance acquisition unit 1316 may be implemented by specially designed hardware or by a software module. Furthermore, the distance acquisition unit 1316 may be implemented by an FPGA (Field Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit), or by a combination thereof.

[0069] The photoelectric conversion system 1300 is connected to the vehicle information acquisition device 1320 and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. The photoelectric conversion system 1300 is also connected to the ECU 1330, which is a control unit that outputs a control signal to generate braking force on the vehicle based on the judgment result of the collision judgment unit 1318. The photoelectric conversion system 1300 is also connected to the warning device 1340, which issues a warning to the driver based on the judgment result of the collision judgment unit 1318. For example, if the collision judgment unit 1318 determines that there is a high probability of collision, the ECU 1330 controls the drive unit (mechanical device) 1360 by applying the brakes, releasing the accelerator, or suppressing engine output to perform vehicle control to avoid a collision or mitigate damage. The warning device 1340 warns the user by sounding an alarm, displaying warning information on a screen such as a car navigation system, or vibrating the seat belt or steering wheel.

[0070] In this embodiment, the photoelectric conversion system 1300 images the area around the vehicle (mobile body 1301), for example, in front of or behind it. Figure 17(b) shows the photoelectric conversion system when imaging the area in front of the vehicle (imaging range 1350). The vehicle information acquisition device 1320 sends instructions to the photoelectric conversion system 1300 or the imaging device 1310. This configuration can further improve the accuracy of distance measurement.

[0071] The above example describes control to prevent collisions with other vehicles, but the photoelectric conversion system 1300 can also be applied to control systems that automatically follow other vehicles or automatically drive to prevent vehicles from straying from their lanes. Furthermore, the photoelectric conversion system 1300 can be applied not only to vehicles such as automobiles, but also to mobile bodies (mobile devices) such as ships, aircraft, or industrial robots. This mobile body mainly includes a drive force generation unit that generates the driving force used for the movement of the mobile body, and one or both of a rotating body mainly used for the movement of the mobile body. The drive force generation unit may be an engine or motor. The rotating body may be a tire, wheel, ship's propeller, aircraft propeller, etc. In addition, it can be applied not only to mobile bodies, but also to a wide range of devices that utilize object recognition, such as intelligent transportation systems (ITS).

[0072] Figure 18 is a block diagram showing an example configuration of a distance image sensor 1401, which is a photoelectric conversion system. As shown in Figure 18, the distance image sensor 1401 is composed of an optical system 1407, a photoelectric conversion device 1408, an image processing circuit 1404, a monitor 1405, and a memory 1406. The distance image sensor 1401 receives light (modulated light or pulsed light) that is projected from a light source device 1409 toward the subject and reflected from the surface of the subject, thereby acquiring a distance image corresponding to the distance to the subject.

[0073] The optical system 1407 is composed of one or more lenses and guides the image light (incident light) from the subject to the photoelectric converter 1408, where it forms an image on the light-receiving surface (sensor part) of the photoelectric converter 1408.

[0074] The photoelectric converter 1408 is the same as the photoelectric converter 100 described above, and a distance signal indicating the distance, which is determined from the light received signal output from the photoelectric converter 1408, is supplied to the image processing circuit 1404.

[0075] The image processing circuit 1404 performs image processing to construct a distance image based on the distance signal supplied from the photoelectric converter 1408. The distance image (image data) obtained through this image processing is then supplied to the monitor 1405 for display or supplied to the memory 1406 for storage (recording).

[0076] With the distance image sensor 1401 configured in this way, by applying the photoelectric converter 100 described above, the characteristics of the pixels are improved, and for example, more accurate distance images can be acquired.

[0077] Figure 19 shows an example of a schematic configuration of an endoscopic surgical system 1250, which is a photoelectric conversion system. Figure 19 illustrates a surgeon (physician) 1231 performing surgery on a patient 1232 on a patient bed 1233 using the endoscopic surgical system 1250. As shown in the figure, the endoscopic surgical system 1250 consists of an endoscope 1200, surgical instruments 1210, and a cart 1234 equipped with various devices for endoscopic surgery.

[0078] The endoscope 1200 comprises a barrel 1201, the portion of which a predetermined length from the tip is inserted into the body cavity of the patient 1232, and a camera head 1202 connected to the proximal end of the barrel 1201. In the illustrated example, the endoscope 1200 is shown as a so-called rigid endoscope having a rigid barrel 1201, but the endoscope 1200 may also be configured as a so-called flexible endoscope having a flexible barrel.

[0079] An opening into which an objective lens is fitted is provided at the tip of the endoscope tube 1201. A light source device 1203 is connected to the endoscope 1200, and the light generated by the light source device 1203 is guided to the tip of the endoscope tube by a light guide extending inside the endoscope tube 1201, and is irradiated through the objective lens towards the object to be observed inside the body cavity of the patient 1232. The endoscope 1200 may be a straight-viewing endoscope, an oblique-viewing endoscope, or a side-viewing endoscope.

[0080] The camera head 1202 contains an optical system and a photoelectric converter. Reflected light from the object being observed (observation light) is focused by the optical system into the photoelectric converter. The photoelectric converter converts the observation light into electrical signals, generating an electrical signal corresponding to the observation light, i.e., an image signal corresponding to the observed image. The photoelectric converter 100 (imaging device) described above can be used as the photoelectric converter. The image signal is transmitted as RAW data to the camera control unit (CCU) 1235.

[0081] The CCU1235 consists of a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit), and comprehensively controls the operation of the endoscope 1200 and the display device 1236. Furthermore, the CCU1235 receives an image signal from the camera head 1202 and performs various image processing operations on that image signal, such as development processing (demosaic processing), to display an image based on that image signal.

[0082] The display device 1236 displays an image based on an image signal that has been processed by the CCU 1235, under control from the CCU 1235.

[0083] The light source device 1203 consists of a light source such as an LED (Light Emitting Diode) and supplies illumination light to the endoscope 1200 when photographing the surgical area.

[0084] The input device 1237 is an input interface for the endoscopic surgical system 1250. The user can input various types of information and instructions to the endoscopic surgical system 1250 via the input device 1237.

[0085] The treatment instrument control device 1238 controls the driving of the energy treatment instrument 1212 for purposes such as tissue cauterization, incision, or blood vessel sealing.

[0086] The light source device 1203, which supplies illumination light to the endoscope 1200 when photographing the surgical area, can be composed of, for example, an LED, a laser light source, or a combination thereof. When the white light source is composed of a combination of RGB laser light sources, the output intensity and output timing of each color (each wavelength) can be controlled with high precision, so the white balance of the captured image can be adjusted in the light source device 1203. In this case, it is also possible to capture images corresponding to each of the RGB colors in time-division by irradiating the observation target with laser light from each of the RGB laser light sources in time-division and controlling the drive of the image sensor of the camera head 1202 in synchronization with the irradiation timing. According to this method, a color image can be obtained without providing a color filter on the image sensor.

[0087] Furthermore, the light source device 1203 may be controlled to change the intensity of the light it outputs at predetermined time intervals. By controlling the drive of the image sensor of the camera head 1202 in synchronization with the timing of the change in light intensity, images can be acquired in time-division order, and these images can be combined to generate high dynamic range images without so-called black crushing and white clipping.

[0088] Furthermore, the light source device 1203 may be configured to supply light in a predetermined wavelength band corresponding to special light observation. In special light observation, for example, the wavelength dependence of light absorption in body tissue is utilized. Specifically, by irradiating with narrowband light compared to the irradiation light used during normal observation (i.e., white light), predetermined tissues such as blood vessels on the surface of mucosa can be imaged with high contrast. Alternatively, in special light observation, fluorescence observation may be performed to obtain an image using fluorescence generated by irradiation with excitation light. In fluorescence observation, excitation light can be irradiated onto body tissue and fluorescence from the body tissue can be observed, or a reagent such as indocyanine green (ICG) can be injected into body tissue and the body tissue can be irradiated with excitation light corresponding to the fluorescence wavelength of the reagent to obtain a fluorescence image. The light source device 1203 may be configured to supply narrowband light and / or excitation light corresponding to such special light observation.

[0089] Figures 20(a) and 20(b) illustrate the photoelectric conversion system, specifically eyeglasses 1600 and 1610 (smart glasses). The eyeglasses 1600 shown in Figure 20(a) have a photoelectric conversion device 1602. The photoelectric conversion device 1602 is the aforementioned photoelectric conversion device 100 (imaging device). In addition, a display device including a light-emitting device such as an OLED or LED may be provided on the back side of the lens 1601. There may be one or more photoelectric conversion devices 1602. Furthermore, multiple types of photoelectric conversion devices may be used in combination. The arrangement position of the photoelectric conversion device 1602 is not limited to that shown in Figure 20(a).

[0090] The eyeglasses 1600 further include a control device 1603. The control device 1603 functions as a power source that supplies power to the photoelectric converter 1602 and the display device. The control device 1603 also controls the operation of the photoelectric converter 1602 and the display device. The lens 1601 has an optical system formed therein for focusing light onto the photoelectric converter 1602.

[0091] Figure 20(b) illustrates a pair of glasses 1610 (smart glasses) relating to one application example. The glasses 1610 have a control device 1612, which is equipped with a photoelectric converter equivalent to a photoelectric converter 1602 and a display device. The lens 1611 has an optical system formed therein for projecting light emitted from the photoelectric converter in the control device 1612 and from the display device, and an image is projected onto the lens 1611. The control device 1612 functions as a power supply that provides power to the photoelectric converter and the display device, and also controls the operation of the photoelectric converter and the display device. The control device may have a gaze detection unit that detects the wearer's gaze. Gaze detection may use infrared light. The infrared light emitter emits infrared light towards the eyeball of the user who is fixating on the displayed image. An imaging unit having a light-receiving element detects the reflected light from the eyeball of the emitted infrared light, thereby obtaining an image of the eyeball. By having a reduction means that reduces the light from the infrared light emitter to the display unit in planar view, the deterioration of image quality is reduced.

[0092] The user's gaze towards a displayed image is detected from an image of the eyeball obtained by imaging with infrared light. Any known method can be applied to gaze detection using an image of the eyeball. As an example, a gaze detection method based on the Purkinje image obtained by the reflection of the irradiated light from the cornea can be used.

[0093] More specifically, gaze detection processing is performed based on the pupil-corneal reflection method. Using the pupil-corneal reflection method, a gaze vector representing the orientation (rotation angle) of the eyeball is calculated based on the pupil image and Purkinje image contained in the captured image of the eyeball, thereby detecting the user's gaze.

[0094] The display device of this embodiment includes a photoelectric converter having a light-receiving element, and may control the display image of the display device based on the user's gaze information from the photoelectric converter.

[0095] Specifically, the display device determines a first field of view that the user is fixated on, and a second field of view other than the first field of view, based on gaze information. The first and second field of view may be determined by the control device of the display device, or they may be determined by an external control device and received by the display device. Within the display area of ​​the display device, the display resolution of the first field of view may be controlled to be higher than the display resolution of the second field of view. In other words, the resolution of the second field of view may be lower than that of the first field of view.

[0096] Furthermore, the display area has a first display area and a second display area different from the first display area, and a higher priority area may be determined from the first and second display areas based on gaze information. The first and second view areas may be determined by the control device of the display device, or they may be determined by an external control device and received. The resolution of the higher priority area may be controlled to be higher than the resolution of the areas other than the higher priority area. In other words, the resolution of areas with relatively lower priority may be set lower.

[0097] AI may be used to determine the first field of view area and high-priority areas. The AI ​​may be a model configured to estimate the angle of gaze and the distance to the target object at the end of the line of sight from the image of the eye, using the image of the eye and the direction the eye was actually looking in that image as training data. The AI ​​program may be installed in the display device, the photoelectric converter, or an external device. If installed in an external device, it will be transmitted to the display device via communication.

[0098] When display control is based on visual detection, this can be applied to smart glasses that further have a photoelectric converter for capturing images of the surroundings. The smart glasses can display the captured external information in real time.

[0099] The disclosures herein include the following photoelectric converters, photoelectric converter systems, mobile devices, equipment, and methods for manufacturing photoelectric converters.

[0100] (Item 1) A photoelectric conversion device comprising a semiconductor layer having a first main surface and a second main surface and comprising a first photoelectric conversion element and a second photoelectric conversion element adjacent to each other, and an element isolation section arranged to electrically isolate the first photoelectric conversion element and the second photoelectric conversion element, A cured product of the curable composition is placed on the first main surface. The cured material is provided with a plurality of trenches extending from the surface of the cured material toward the first main surface, The photoelectric conversion device is characterized in that the plurality of trenches include a first trench that constitutes a scattering diffraction structure arranged to overlap the first photoelectric conversion element, and a second trench that constitutes a separation structure arranged to overlap the element separation portion.

[0101] (Item 2) A functional layer including a pinning layer is disposed between the first main surface and the cured product. The photoelectric conversion device according to item 1, characterized in that the plurality of trenches reach the functional layer.

[0102] (Item 3) The photoelectric conversion device according to item 1 or 2, characterized in that the second trench extends to the element isolation section.

[0103] (Item 4) The photoelectric conversion apparatus according to item 1, characterized in that a portion of the cured material is disposed between the bottom surfaces of the plurality of trenches and the first main surface.

[0104] (Item 5) The surface has a recess that is curved toward the first main surface, The photoelectric conversion device according to any one of items 1 to 4, characterized in that the first trench is disposed in the recess.

[0105] (Item 6) The photoelectric conversion device according to item 5, characterized in that a material with a refractive index different from that of the cured product is embedded in the plurality of trenches and the recesses.

[0106] (Item 7) A photoelectric conversion device according to any one of items 1 to 4, characterized in that a material with a refractive index different from that of the hardened product is embedded in the plurality of trenches.

[0107] (Item 8) The photoelectric conversion device according to item 6 or 7, characterized in that the refractive index of the cured product is greater than the refractive index of the material.

[0108] (Item 9) A planarizing layer is placed so as to cover the aforementioned cured product. The photoelectric conversion device according to any one of items 6 to 8, characterized in that the material embedded in the plurality of trenches is integrally formed with at least a portion of the planarization layer.

[0109] (Item 10) A planarizing layer is placed so as to cover the aforementioned cured product. A photoelectric conversion device according to any one of items 1 to 9, characterized in that a microlens is arranged on the planarization layer so as to overlap the first photoelectric conversion element.

[0110] (Item 11) A photoelectric conversion device according to any one of items 1 to 10, characterized in that metal oxide particles are added to the cured product.

[0111] (Item 12) The photoelectric conversion device according to any one of items 1 to 11, characterized in that the first photoelectric conversion element and the second photoelectric conversion element are each avalanche photodiodes.

[0112] (Item 13) It further includes a semiconductor layer, separate from the semiconductor layer, that is arranged to face the second main surface, The photoelectric conversion device according to any one of items 1 to 12, characterized in that the other semiconductor layer is provided with an element for operating the first photoelectric conversion element and the second photoelectric conversion element.

[0113] (Item 14) A photoelectric conversion device comprising a semiconductor layer having a first main surface and a second main surface and equipped with a photoelectric conversion element, A cured product of the curable composition is placed on the first main surface. The cured material is provided with a scattering diffraction structure that overlaps with the photoelectric conversion element. The photoelectric conversion device is characterized in that the scattering diffraction structure includes a recess formed on the surface of the cured material that is curved and recessed toward the first main surface, and a lattice portion formed by trenches extending from the recess toward the first main surface.

[0114] (Item 15) A photoelectric converter described in any one of items 1 through 14, A signal processing unit that generates an image using the signal output by the aforementioned photoelectric converter, A photoelectric conversion system characterized by comprising the following features.

[0115] (Item 16) A mobile body equipped with a photoelectric converter described in any one of items 1 to 14, A mobile body characterized by having a control unit that controls the movement of the mobile body using a signal output by the photoelectric converter.

[0116] (Item 17) A device equipped with a photoelectric converter described in any one of items 1 to 14, Optical device corresponding to the aforementioned photoelectric converter, A control device for controlling the aforementioned photoelectric converter, A processing device that processes the signal output from the aforementioned photoelectric converter, A display device that displays information obtained by the aforementioned photoelectric converter. A storage device for storing information obtained by the photoelectric converter, and The apparatus is further characterized by comprising at least one of the following: a mechanical device that operates based on information obtained from the photoelectric converter.

[0117] (Item 18) A method for manufacturing a photoelectric conversion device, comprising: a semiconductor layer having a first main surface and a second main surface and comprising a first photoelectric conversion element and a second photoelectric conversion element adjacent to each other; a separation portion disposed to electrically separate the first photoelectric conversion element and the second photoelectric conversion element; and a scattering diffraction structure disposed on the first main surface so as to overlap the first photoelectric conversion element and a separation structure disposed so as to overlap the separation portion, wherein A manufacturing method characterized by including a step of forming trenches constituting the scattering diffraction structure and trenches constituting the separation structure on the first main surface using an imprint process, wherein the trenches constituting the separation structure are made of a cured product of a curable composition.

[0118] (Item 19) A method for manufacturing a photoelectric conversion device, comprising a semiconductor layer having a first main surface and a second main surface and comprising a photoelectric conversion element, and a scattering diffraction structure disposed on the first main surface so as to overlap the photoelectric conversion element, The process includes a step of forming trenches constituting the scattering diffraction structure, which are made of a cured product of a curable composition, using an imprint process. The surface of the cured product has recesses that are curved and recessed toward the first main surface formed by the imprint process, A manufacturing method characterized in that the trench is located in the recess.

[0119] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0120] 100: Photoelectric converter, 301: Semiconductor layer, 324: Element isolation section, 350: Cured material, 351: Trench, 391, 392: Main surface

Claims

1. A photoelectric conversion device comprising a semiconductor layer having a first main surface and a second main surface and comprising a first photoelectric conversion element and a second photoelectric conversion element adjacent to each other, and an element isolation section arranged to electrically isolate the first photoelectric conversion element and the second photoelectric conversion element, A cured product of the curable composition is placed on the first main surface. The cured material is provided with a plurality of trenches extending from the surface of the cured material toward the first main surface, The photoelectric conversion device is characterized in that the plurality of trenches include a first trench that constitutes a scattering diffraction structure arranged to overlap the first photoelectric conversion element, and a second trench that constitutes a separation structure arranged to overlap the element separation portion.

2. A functional layer including a pinning layer is disposed between the first main surface and the cured product. The photoelectric conversion apparatus according to claim 1, characterized in that the plurality of trenches reach the functional layer.

3. The photoelectric conversion apparatus according to claim 1, characterized in that the second trench extends to the element isolation section.

4. The photoelectric conversion apparatus according to claim 1, characterized in that a portion of the cured material is disposed between the bottom surfaces of the plurality of trenches and the first main surface.

5. The surface has a recess that is curved toward the first main surface, The photoelectric conversion device according to claim 1, characterized in that the first trench is disposed in the recess.

6. The photoelectric conversion device according to claim 5, characterized in that a material with a refractive index different from that of the cured product is embedded in the plurality of trenches and the recesses.

7. The photoelectric conversion device according to claim 1, characterized in that a material with a refractive index different from that of the cured product is embedded in the plurality of trenches.

8. The photoelectric conversion device according to claim 6, characterized in that the refractive index of the cured product is greater than the refractive index of the material.

9. A planarizing layer is placed so as to cover the aforementioned cured product. The photoelectric conversion device according to claim 6, characterized in that the material embedded in the plurality of trenches is integrally formed with at least a portion of the planarization layer.

10. A planarizing layer is placed so as to cover the aforementioned cured product. The photoelectric conversion apparatus according to claim 1, characterized in that a microlens is arranged on the planarization layer so as to overlap the first photoelectric conversion element.

11. The photoelectric conversion apparatus according to claim 1, characterized in that metal oxide particles are added to the cured product.

12. The photoelectric conversion device according to claim 1, characterized in that the first photoelectric conversion element and the second photoelectric conversion element are each avalanche photodiodes.

13. It further includes a semiconductor layer, separate from the semiconductor layer, that is arranged to face the second main surface, The photoelectric conversion device according to claim 1, characterized in that the other semiconductor layer is provided with an element for operating the first photoelectric conversion element and the second photoelectric conversion element.

14. A photoelectric conversion device comprising a semiconductor layer having a first main surface and a second main surface and equipped with a photoelectric conversion element, A cured product of the curable composition is placed on the first main surface. The cured material is provided with a scattering diffraction structure that overlaps with the photoelectric conversion element. The photoelectric conversion device is characterized in that the scattering diffraction structure includes a recess formed on the surface of the cured material that is curved and recessed toward the first main surface, and a lattice portion formed by trenches extending from the recess toward the first main surface.

15. A photoelectric conversion device according to any one of claims 1 to 14, A signal processing unit that generates an image using the signal output by the aforementioned photoelectric converter, A photoelectric conversion system characterized by comprising the following features.

16. A mobile body comprising a photoelectric converter according to any one of claims 1 to 14, A mobile body characterized by having a control unit that controls the movement of the mobile body using a signal output by the photoelectric converter.

17. A device comprising a photoelectric converter according to any one of claims 1 to 14, Optical device corresponding to the aforementioned photoelectric converter, A control device for controlling the aforementioned photoelectric converter, A processing device that processes the signal output from the aforementioned photoelectric converter, A display device that displays information obtained by the aforementioned photoelectric converter. A storage device for storing information obtained by the photoelectric converter, and The apparatus is further characterized by comprising at least one of the following: a mechanical device that operates based on information obtained from the photoelectric converter.

18. A method for manufacturing a photoelectric conversion device, comprising: a semiconductor layer having a first main surface and a second main surface and comprising a first photoelectric conversion element and a second photoelectric conversion element adjacent to each other; a separation portion disposed to electrically separate the first photoelectric conversion element and the second photoelectric conversion element; and a scattering diffraction structure disposed on the first main surface so as to overlap the first photoelectric conversion element and a separation structure disposed so as to overlap the separation portion, wherein A manufacturing method characterized by including a step of forming trenches constituting the scattering diffraction structure and trenches constituting the separation structure on the first main surface using an imprint process, wherein the trenches are made of a cured product of a curable composition.

19. A method for manufacturing a photoelectric conversion device, comprising a semiconductor layer having a first main surface and a second main surface and comprising a photoelectric conversion element, and a scattering diffraction structure disposed on the first main surface so as to overlap the photoelectric conversion element, The process includes a step of forming trenches constituting the scattering diffraction structure, which are made of a cured product of a curable composition, using an imprint process. The surface of the cured product has a recess that is curved and recessed toward the first main surface formed by the imprint process, A manufacturing method characterized in that the trench is located in the recess.

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