Photoelectric conversion device, photoelectric conversion system, mobile object

Abstract

To provide a photoelectric conversion device with reduced noise and leakage between wells due to etching damage on a peripheral circuit part, and to provide a photoelectric conversion system using the same and a mobile body.SOLUTION: A photoelectric conversion device 1000 has a semiconductor substrate 1. The semiconductor substrate has a pixel area 1001 and a peripheral circuit area 1002 for processing a signal generated in the pixel area 1001. The peripheral circuit area has a P-type semiconductor area 9, an N-type semiconductor area 8, a fixed charge film 12 having a negative fixed charge on a light incident surface side of the P-type semiconductor area, and a fixed charge film 13 having a positive fixed charge on the light incident surface side of the N-type semiconductor area. The fixed charge film having a negative fixed charge and the fixed charge film having a positive fixed charge are aligned in a direction parallel to the light incident surface.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a photoelectric conversion device, a photoelectric conversion system using the photoelectric conversion device, and a mobile object. [Background technology]

[0002] In the manufacturing process of a photoelectric conversion device, if lattice defects or the like occur in the substrate crystal due to processing such as etching, these lattice defects can become a noise source for dark current, etc. Patent Document 1 describes a manufacturing method for a photoelectric conversion device in which a negative fixed charge film that forms a hole accumulation layer on the light incident surface of the sensor part is formed, and then the fixed charge film in the peripheral circuit part is removed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2009-88430 Summary of the Invention [Problem to be solved by the invention]

[0004] When removing the fixed charge film overlapping the peripheral circuit section, unless a film that lowers the interface state is formed under the fixed charge film as shown in Patent Document 1, etching damage to the substrate can occur to a considerable extent, and lattice defects can occur in the crystal of the substrate. These lattice defects can become a source of noise when the circuit is operating.

[0005] Furthermore, if an insulating film such as a silicon oxide film is formed after removing the negative fixed charge film in the peripheral circuit area, the resulting silicon oxide film may become a positive fixed charge film. Multiple N-type well regions, each of which acts as an electron accumulation layer, are provided on the light-incident side of the peripheral circuit area. The presence of the positive fixed charge film makes it easier for electrons to gather on the substrate surface, weakening the barrier separating the multiple N-type well regions. This can lead to leakage current flowing between the multiple N-type well regions. [Means for solving the problem]

[0006] One aspect of the present invention is a photoelectric conversion device having a semiconductor substrate, the device having a light incident surface, the semiconductor substrate having a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit, the peripheral circuit region having a P-type semiconductor region and an N-type semiconductor region, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region, a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region, the fixed charge film having negative fixed charges On the surface of the P-type semiconductor region facing the fixed charge film having the negative fixed charges, The hole accumulation layer Form , the fixed charge film having the positive fixed charge is On the surface of the N-type semiconductor region facing the fixed charge film having the positive fixed charges, Electron accumulation layer Form The P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region, the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region, and the fixed charge film having a negative fixed charge and the fixed charge film having a positive fixed charge are aligned in a direction parallel to the light incident surface.

[0007] Another aspect of the present invention is a method for manufacturing a photoelectric conversion device having a semiconductor substrate, the semiconductor substrate having a photoelectric conversion unit and a peripheral circuit region that processes a signal generated by the photoelectric conversion unit, the peripheral circuit region comprising: a first P-type semiconductor region and a second P-type semiconductor region; a P-type semiconductor region; disposed between the first P-type semiconductor region and the second P-type semiconductor region an N-type semiconductor region, and a light incident surface side of the semiconductor substrate, the light incident surface side of the semiconductor substrate being such that the P-type semiconductor region and the N-type semiconductor region are covered with the light incident surface side of the semiconductor substrate; , including a hole accumulation layer; a step of forming a fixed charge film having negative fixed charges; a step of removing the fixed charge film having negative fixed charges from the light incident surface side of the N-type semiconductor region and leaving the fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; forming a fixed charge film including an electron accumulation layer and having positive fixed charges so as to cover the N-type semiconductor region on the light incident surface side of the semiconductor substrate; The present invention is characterized by having the following.

[0008] Yet another aspect of the present invention is a method for manufacturing a photoelectric conversion device having a semiconductor substrate, the semiconductor substrate having a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit, the peripheral circuit region comprising: a first P-type semiconductor region and a second P-type semiconductor region; a P-type semiconductor region; disposed between the first P-type semiconductor region and the second P-type semiconductor region an N-type semiconductor region, and a light incident surface side of the semiconductor substrate, the light incident surface side of the semiconductor substrate being such that the P-type semiconductor region and the N-type semiconductor region are covered with the light incident surface side of the semiconductor substrate; , including a hole accumulation layer; forming a fixed charge film having negative fixed charges; an electron accumulation layer covering the P-type semiconductor region but not covering the P-type semiconductor region; A fixed charge film with a positive fixed charge On the light incident surface side of the semiconductor substrate formation do The method is characterized by comprising the steps of:

[0009] Yet another aspect of the present invention is a semiconductor substrate, the semiconductor substrate having a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit, the peripheral circuit region having a P-type semiconductor region and an N-type semiconductor region, a fixed charge film having negative fixed charges on the light incident surface side of a region that overlaps with the P-type semiconductor region in a plan view from the light incident surface side, and a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region, the fixed charge film having negative fixed charges On the surface of the P-type semiconductor region facing the fixed charge film having the negative fixed charges, The hole accumulation layer Form , the fixed charge film having the positive fixed charge is On the surface of the N-type semiconductor region facing the fixed charge film having the positive fixed charges, Electron accumulation layer Form The P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region, the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region, and the fixed charge film having a negative fixed charge and the fixed charge film having a positive fixed charge are aligned in a direction parallel to the light incident surface. [Effects of the Invention]

[0010] According to the present invention, it is possible to reduce noise and inter-well leakage occurring in the peripheral circuit section. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic diagram of a photoelectric conversion device according to a first embodiment. [Figure 2] 1 is a schematic cross-sectional view of a photoelectric conversion device according to a first embodiment. [Figure 3] FIG. 10 is a schematic diagram of a photoelectric conversion device according to a second embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view of a photoelectric conversion device according to a second embodiment. [Figure 5] FIG. 10 is a schematic diagram of a photoelectric conversion device according to a third embodiment. [Figure 6] FIG. 10 is a schematic cross-sectional view of a photoelectric conversion device according to a third embodiment. [Figure 7] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 8] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 9] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 10] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 11] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 12] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 13] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 14] 10A to 10C are explanatory views showing a method for manufacturing a photoelectric conversion device according to a fourth embodiment. [Figure 15] FIG. 10 is a functional block diagram of a photoelectric conversion system according to a fifth embodiment. [Figure 16] FIG. 10 is a diagram illustrating a photoelectric conversion system and a moving object according to a sixth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, a photoelectric conversion device according to an embodiment of the present invention will be described with reference to the drawings.

[0013] In the following embodiments, an image pickup device will be mainly described as an example of a photoelectric conversion device to which the present invention can be applied, but the application of the embodiments is not limited to image pickup devices. For example, the present invention can be applied to distance measurement devices (devices for measuring distance using focus detection or TOF (Time Of Flight)), photometry devices (devices for measuring the amount of incident light, etc.), etc.

[0014] Furthermore, the conductivity types of semiconductor regions such as diffusion regions and wells and the dopants to be implanted described in the following embodiments are merely examples and are not limited to the conductivity types and dopants described in the embodiments. The conductivity types and dopants described in the embodiments can be changed as appropriate, and the potentials of semiconductor regions such as diffusion regions and wells will be changed as appropriate in accordance with these changes.

[0015] (First embodiment) A first embodiment for carrying out the present invention will be described with reference to FIGS.

[0016] 1 is a schematic diagram of a photoelectric conversion device according to the first embodiment. The photoelectric conversion device according to this embodiment is a back-illuminated CMOS (Complementary Metal Oxide Semiconductor) image sensor using an N-type semiconductor substrate.

[0017] 1 includes a pixel region 1001 in which a plurality of pixels are arranged, and a peripheral circuit region 1002 in which circuits are arranged that control the driving of each pixel in the pixel region 1001 and process and output signals obtained by each pixel. The number of pixels that make up the pixel region 1001 is not particularly limited. For example, the pixel region 1001 may be configured with several thousand rows and several thousand columns of pixels, as in a general digital camera, or may be configured with several pixels arranged in a single row or column.

[0018] FIG. 2 is a schematic cross-sectional view of the photoelectric conversion device 1000 according to the first embodiment taken along line AA′ in FIG.

[0019] The photoelectric conversion device 1000 shown in Fig. 2 has a substrate 1 including a semiconductor substrate and a support substrate 2. The upper surface (the uppermost surface) in Fig. 2 is the light incident surface of the substrate 1. A support substrate 2 is provided on the surface opposite to the light incident surface to reinforce the strength of the substrate 1. In Fig. 2, light is incident on the light incident surface from above the substrate 1.

[0020] The substrate 1 further includes a negative fixed charge film 12, a positive fixed charge film 13, and a light-shielding film 14 on the light incident surface side of the semiconductor substrate, and wiring 16 and an interlayer film 17 on the surface of the semiconductor substrate opposite to the light incident surface.

[0021] Substrate 1 includes an N-type semiconductor substrate. For example, a silicon substrate doped with N-type impurities can be used as the N-type semiconductor substrate. Substrate 1 includes, as semiconductor regions within this semiconductor substrate, a first P-type diffusion region 3, a first N-type diffusion region 4, a second P-type diffusion region 5, and a third P-type diffusion region 6. Substrate 1 also includes, as semiconductor regions, a first P-type well 7, a first N-type well 8, a second P-type well 9, a second N-type well 10, and a third P-type well 11.

[0022] For example, a silicon substrate can be used for the support substrate 2. The substrate 1 and the support substrate 2 can be connected by, for example, plasma activated bonding. Transistors and wiring (not shown) may be provided on the support substrate 2, which is electrically connected to the substrate 1 and has the function of processing signals output from the substrate 1.

[0023] The arrangement and function of each element on the substrate 1 will be explained.

[0024] A pixel region 1001 in the semiconductor substrate of the substrate 1 is arranged with a first P-type diffusion region 3, a first N-type diffusion region 4, a second P-type diffusion region 5, and a third P-type diffusion region 6 to form an electron accumulation type photodiode as a photoelectric conversion unit. Furthermore, a transfer transistor, a reset transistor, a selection transistor, an amplification transistor, etc. (not shown) are also arranged in the pixel region 1001. Light incident on the light incident surface of the pixel region 1001 is photoelectrically converted at the interface between the diffusion region 3 or 5 and the diffusion region 4, and the generated electrons are accumulated in the first N-type diffusion region 4.

[0025] A first P-type well 7, a first N-type well 8, a second P-type well 9, a second N-type well 10, and a third P-type well 11 are arranged in a peripheral circuit region 1002 in the semiconductor substrate of the substrate 1. Devices necessary for signal processing, such as transistors and resistors (not shown), are arranged in each well.

[0026] A negative fixed charge film 12 is formed on the light incident surface side of the second P-type diffusion region 5, the first P-type well 7, the second P-type well 9, and the third P-type well 11. On the other hand, a positive fixed charge film 13 is formed on the light incident surface side of the first N-type well 8 and the second N-type well 10.

[0027] The negative fixed charge film 12 can be formed of, for example, aluminum oxide, hafnium oxide, tantalum oxide, titanium oxide, zirconium oxide, etc. The configuration of the fixed charge film 12 is not limited to this, and other types of films or a combination of multiple film types can be used as long as they have the function of having negative fixed charges.

[0028] On the other hand, the positive fixed charge film 13 can be formed of a film such as a silicon oxide film or a silicon nitride film, but other films or a combination of multiple film types may be used as long as they have the function of having a positive fixed charge. In this description, a silicon oxide film is used as the material for the positive fixed charge film 13, and the fixed charge film 13 also has the function of insulating between wirings as an interlayer film in the pixel region and the peripheral circuit region.

[0029] A light-shielding film 14 is formed in the positive fixed charge film 13 so as to cover the spaces between the pixels and the peripheral circuit region, thereby reducing the occurrence of stray light and color mixing. Furthermore, by forming a color filter, a microlens, a waveguide, etc. (not shown) on the light incident surface side of the photoelectric conversion device 1000, it is possible to collect light of different colors and efficiently take the collected light into the photodiode section (diffusion regions 3 to 6).

[0030] 2, by arranging the negative fixed charge film 12 and the positive fixed charge film 13 in a direction parallel to the light incident surface, the hole accumulation layer created by the negative fixed charge film 12 is connected to the second P-type diffusion region 5 and the first to third P-type wells 7, 9, and 11. In addition, by connecting the electron accumulation layer created by the positive fixed charge film 13 to the first N-type well 8 and the second N-type well 10, a potential difference is generated between semiconductor regions of the same conductivity type, and the semiconductor regions can be separated.

[0031] This makes it possible to reduce leakage current that can occur between semiconductor regions of the same conductivity type, for example, between the first P-type well 7 and the second P-type well 9 or the third P-type well 11. Similarly, it is possible to reduce leakage current that can occur between the first N-type well 8 and the second N-type well 10.

[0032] 2 shows an example of a state in which the negative fixed charge film 12 and the positive fixed charge film 13 are aligned in a direction parallel to the light incident surface, but the arrangement of the negative fixed charge film 12 and the positive fixed charge film 13 is not limited to this. For example, even if the surface positions of the negative fixed charge film 12 and the positive fixed charge film 13 are offset in the height direction perpendicular to the light incident surface, the negative fixed charge film 12 and the positive fixed charge film 13 can be said to be aligned as long as the negative fixed charge film 12 and the positive fixed charge film 13 are provided at a certain height. Furthermore, the alignment of the negative fixed charge film 12 and the positive fixed charge film 13 does not necessarily mean that these films are adjacent to each other, and another member may be disposed between the negative fixed charge film 12 and the positive fixed charge film 13.

[0033] 2, the negative fixed charge film 12 is disposed in the region above the second P-type diffusion region 5 and on the first to third P-type wells 7, 9, and 11, but the arrangement of the negative fixed charge film 12 is not limited to this. For example, as long as the leakage current can be reduced, the negative fixed charge film 12 may be disposed in a range that partially protrudes onto the first N-type well 8 or overlaps only a portion of the second P-type well region.

[0034] Furthermore, an insulating film (not shown) may be formed between the negative fixed charge film 12 and the positive fixed charge film 13 and each of the second P-type diffusion region 5 and the first to third P-type wells 7, 9, and 11, as long as the charge fixing function of each film is not lost. The formed insulating film can be used as an etching stop film when etching the region of the negative fixed charge film 12 that overlaps with the first N-type well 8 and the second N-type well 10, thereby mitigating damage to the substrate due to etching. At this time, since the negative fixed charge film 12 remains on the first to third P-type wells 7, 9, and 11, damage to the substrate during etching can be suppressed.

[0035] In this way, damage during processing and the generation of noise due to the damage can be suppressed.

[0036] This configuration can also be expressed as follows: A negative fixed charge film is provided on the light incident surface side of the P-type well in the peripheral circuit region, and a positive fixed charge film is provided on the light incident surface side of the N-type well. The positive fixed charge film does not extend from the light incident surface side of the N-type well to the light incident surface side of the P-type well, or extends only to the light incident surface side of a portion of the P-type well. Alternatively, the negative fixed charge film does not extend from the light incident surface side of the P-type well to the light incident surface side of the N-type well, or extends only to the light incident surface side of a portion of the N-type well.

[0037] (Second embodiment) A second embodiment for carrying out the present invention will be described with reference to FIGS.

[0038] 3 is a schematic diagram of a photoelectric conversion device according to a second embodiment. The photoelectric conversion device according to this embodiment is a back-illuminated CMOS image sensor using a P-type semiconductor substrate.

[0039] 3 includes a pixel region 2001 in which a plurality of pixels are arranged, and a peripheral circuit region 2002 in which circuits are arranged that control the driving of each pixel in the pixel region 2001 and process and output signals obtained by each pixel. The number of pixels constituting the pixel region 2001 is not particularly limited. For example, the pixel region 2001 may be constituted by several thousand rows and several thousand columns of pixels, as in a general digital camera, or may be constituted by several pixels arranged in a single row or column.

[0040] FIG. 4 is a schematic cross-sectional view of a photoelectric conversion device 2000 according to the second embodiment taken along line BB' in FIG.

[0041] A photoelectric conversion device 2000 shown in Fig. 4 has a substrate 101 including a semiconductor substrate and a support substrate 102. The upper surface (the uppermost surface) in Fig. 4 is the light incident surface of the substrate 101. A support substrate 102 for reinforcing the strength of the substrate 101 is provided on the surface of the substrate 101 opposite to the light incident surface. In Fig. 4, light is incident on the light incident surface from above the semiconductor substrate 101.

[0042] The substrate 101 further includes a negative fixed charge film 112, a positive fixed charge film 113, and a light-shielding film 114 on the light incident surface side of the semiconductor substrate, and wiring 116 and an interlayer film 117 on the surface of the semiconductor substrate opposite to the light incident surface.

[0043] Substrate 101 includes a P-type semiconductor substrate. For example, a silicon substrate doped with P-type impurities can be used as this semiconductor substrate. Substrate 101 includes, as semiconductor regions within this semiconductor substrate, a first N-type diffusion region 103, a first P-type diffusion region 104, a second N-type diffusion region 105, and a third N-type diffusion region 106. Substrate 101 further includes, as semiconductor regions, a first N-type well 107, a first P-type well 108, a second N-type well 109, a second P-type well 110, and a third N-type well 111.

[0044] The support substrate 102 may be, for example, a silicon substrate. The semiconductor substrate 101 and the support substrate 102 may be connected by, for example, plasma activated bonding. Transistors and wiring (not shown) may be provided on the support substrate 102, which may be electrically connected to the substrate 101 to provide a function of processing signals output from the semiconductor substrate 101.

[0045] The arrangement and function of each element on the substrate 101 will be described.

[0046] In a pixel region 2001 in the semiconductor substrate of the substrate 101, a first N-type diffusion region 103, a first P-type diffusion region 104, a second N-type diffusion region 105, and a third N-type diffusion region 106 are arranged to form a hole-accumulation photodiode as a photoelectric conversion unit. Furthermore, a transfer transistor, a reset transistor, a selection transistor, an amplification transistor, etc. (not shown) are arranged in the pixel region 1001. Light incident on the light incident surface of the pixel region 1001 is photoelectrically converted at the interface between the diffusion region 103 or 105 and the diffusion region 104, and the generated holes are accumulated in the first P-type diffusion region 104.

[0047] A first N-type well 107, a first P-type well 108, a second N-type well 109, a second P-type well 110, and a third N-type well 111 are arranged in a peripheral circuit region 2002 in the semiconductor substrate of the substrate 101. Devices necessary for signal processing, such as transistors and resistors (not shown), are arranged in each well.

[0048] A positive fixed charge film 112 is formed on the light incident surface side of the second N-type diffusion region 105, the first N-type well 107, the second N-type well 109, and the third N-type well 111. On the other hand, a negative fixed charge film 113 is formed on the light incident surface side of the first P-type well 108 and the second P-type well 110.

[0049] The positive fixed charge film 112 can be formed of a film such as a silicon oxide film or a silicon nitride film. The configuration of the fixed charge film 12 is not limited to this, and other films or a combination of multiple film types may be used as long as they have the function of having a positive fixed charge.

[0050] On the other hand, the negative fixed charge film 13 can be formed of, for example, a film of aluminum oxide, hafnium oxide, tantalum oxide, titanium oxide, zirconium oxide, etc. The film composition is not limited to this, and other types of films or multiple film types can be used as long as they have the function of having negative fixed charges.

[0051] In this way, by arranging the positive fixed charge film 112 and the negative fixed charge film 113 so that they are aligned in a direction parallel to the light incident surface, the electron accumulation layer created by the positive fixed charge film 112 is connected to the second N-type diffusion region 105 and the first to third N-type wells 107, 109, and 111. In addition, by connecting the hole accumulation layer created by the negative fixed charge film 113 to the first P-type well 108 and the second P-type well 110, a potential difference is created between semiconductor regions of the same conductivity type, and the semiconductor regions can be separated.

[0052] This makes it possible to reduce leakage current that may occur between semiconductor regions of the same conductivity type, such as the first N-type well 107, the second N-type well 109, and the third N-type well 111. Similarly, it is possible to reduce leakage current that may occur between the first P-type well 108 and the second P-type well 110.

[0053] In this embodiment, the positive fixed charge film 112 is formed, and then the negative fixed charge film 113 is formed. When forming the negative fixed charge film 113, by forming it so that its end overlaps the positive fixed charge film 112, damage during etching into the N-type well or P-type well can be reduced.

[0054] Furthermore, an interlayer film 115 is formed on the light incident surface side of the positive fixed charge film 112 and the negative fixed charge film 113. For this interlayer film 115, a film that does not cancel out the fixed charge function of the positive fixed charge film 112 and the negative fixed charge film 113 must be selected. Specifically, a film containing nitride is used for the interlayer film 115. A light-shielding film 114 is formed in the interlayer film 115 so as to cover the spaces between the pixels and the peripheral circuit region. Such a light-shielding film reduces the occurrence of stray light and color mixing. Furthermore, by forming color filters, microlenses, waveguides, etc. (not shown) on the light incident surface side of the interlayer film 115, light of different colors can be collected and efficiently taken into the photodiode section (diffusion regions 103 to 106).

[0055] This configuration can also be expressed as follows: A negative fixed charge film is present on the light incident surface side of the P-type well in the peripheral circuit region, and a positive fixed charge film is present on the light incident surface side of the N-type well. The positive fixed charge film does not extend from the light incident surface side of the N-type well to the light incident surface side of the P-type well, or extends only to the light incident surface side of a portion of the P-type well. Furthermore, the negative fixed charge film does not extend from the light incident surface side of the P-type well to the light incident surface side of the N-type well, or extends only to the light incident surface side of a portion of the N-type well.

[0056] (Third embodiment) A third embodiment for carrying out the present invention will be described with reference to FIGS.

[0057] 5 is a schematic diagram of a photoelectric conversion device according to a third embodiment. A photoelectric conversion device 3000 according to this embodiment is a back-illuminated CMOS image sensor that uses an N-type semiconductor substrate.

[0058] 5 includes a pixel region 3001 in which a plurality of pixels are arranged, and a peripheral circuit region 3002 in which circuits are arranged that control the driving of each pixel in the pixel region 3001 and process and output signals obtained by each pixel. The number of pixels that make up the pixel region 3001 is not particularly limited. For example, the pixel region 3001 may be configured with several thousand rows and several thousand columns of pixels, as in a general digital camera, or may be configured with several pixels arranged in a single row or column.

[0059] FIG. 6 is a schematic cross-sectional view of a photoelectric conversion device 3000 according to the third embodiment taken along CC' in FIG.

[0060] 6 includes a substrate 201 including a semiconductor substrate and a support substrate 202. The upper surface (the uppermost surface) of the substrate 201 in FIG. 6 is a light incident surface, and a support substrate 202 for reinforcing the strength of the substrate 201 is provided on the surface opposite to the light incident surface.

[0061] The substrate 201 further includes a negative fixed charge film 212, a positive fixed charge film 213, and a light-shielding film 214 on the light incident surface side of the semiconductor substrate, and wiring 216 and an interlayer film 217 on the surface of the semiconductor substrate opposite the light incident surface.

[0062] The substrate 201 includes an N-type semiconductor substrate, and for this semiconductor substrate, for example, a silicon substrate into which N-type impurities are implanted can be used.

[0063] Substrate 201 includes, as semiconductor regions within this semiconductor substrate, a first P-type diffusion region 203, a first N-type diffusion region 204, a second P-type diffusion region 205, and a third P-type diffusion region 206. It also has, as semiconductor regions, a first P-type well 207, a first N-type well 208, a second P-type well 209, a second N-type well 210, and a third P-type well 211.

[0064] The arrangement and function of each element on the substrate 201 will be described.

[0065] In a pixel region 3001 of the semiconductor substrate of the substrate 201, a first P-type diffusion region 203, a first N-type diffusion region 204, a second P-type diffusion region 205, and a third P-type diffusion region 206 are arranged to form an electron accumulation type photodiode as a photoelectric conversion unit. Furthermore, a transfer transistor, a reset transistor, a selection transistor, an amplification transistor, etc. (not shown) are arranged in the pixel region 3001. Electrons generated by photoelectric conversion of light incident on the light incident surface at the interface between the diffusion regions 203 or 205 and 204 are accumulated in the first N-type diffusion region 204.

[0066] A first P-type well 207, a first N-type well 208, a second P-type well 209, a second N-type well 210, and a third P-type well 211 are arranged in a peripheral circuit region 3002 of the semiconductor substrate of the substrate 201. Devices necessary for signal processing, such as transistors and resistors (not shown), are arranged in each well.

[0067] In this embodiment, a negative fixed charge film 212 is formed on the light incident surface side of the second P-type diffusion region 205 and the wells 207 to 211. Furthermore, a positive fixed charge film 213 is formed on the light incident surface side of the first N-type well 208 and the second N-type well 210. In other words, the negative fixed charge film formed on the second P-type well 209 extends between the first N-type well 208, the second N-type well 210 and the positive fixed charge film 213.

[0068] As shown in FIG. 6 , by arranging the negative fixed charge film 212 and the positive fixed charge film 213 in a direction parallel to the light incident surface, the hole accumulation layer created by the negative fixed charge film 212 is connected to the second P-type diffusion region 205 and the first to third P-type wells 207, 209, and 211. At this time, the depletion layer strengthened by the negative fixed charge film 212 is separated by the positive fixed charge film 213 formed on the negative fixed charge film 212. Therefore, regions of the same conductivity type, such as the first N-type well 208 and the second N-type well 210, can be separated in terms of potential. This reduces leakage current that can occur between regions of the same conductivity type, such as between the first P-type well 207, the second P-type well 209, and the third P-type well 211. Similarly, the leakage current that may occur between the first N-type well 208 and the second N-type well 210 can be reduced.

[0069] 6, a light-shielding film 214 is formed in the interlayer film 215 so as to cover the spaces between the pixels and the peripheral circuit region, thereby reducing the occurrence of stray light and color mixing. Furthermore, by forming color filters, microlenses, waveguides, etc. (not shown) on the light incident surface side of the substrate 201, it is possible to collect light of different colors and efficiently take the collected light into the photodiode section (diffusion regions 203 to 206).

[0070] Although the present embodiment has been described with reference to a case where a hole-accumulation photodiode is formed on an N-type semiconductor substrate, the present embodiment may also be applied to a case where an electron-accumulation photodiode is formed on a P-type semiconductor substrate. In this case, a positive fixed charge film is formed on the light incident surface side in the portions overlapping with both the P-type well and the N-type well in plan view, and a negative fixed charge film is formed in the portion overlapping with the P-type well in plan view.

[0071] Such a configuration can be obtained, for example, by forming a positive fixed charge film on the light incident surface side of the region spanning from the N-type diffusion region in the pixel region to the N-type well and P-type well in the peripheral circuit region, and further forming a negative fixed charge film on the light incident surface side of the P-type well. In this case, the positive fixed charge film formed on the N-type well extends between the P-type well and the negative fixed charge film. In other words, the positive fixed charge film extends from the P-type well to the N-type well, and the negative fixed charge film does not extend from the P-type well to the N-type well or extends only over a portion of the N-type well.

[0072] (Fourth embodiment) A method for manufacturing a photoelectric conversion device according to the first embodiment will be described as a fourth embodiment for carrying out the present invention with reference to Fig. 1 and Fig. 7 to Fig. 13. Fig. 7 to Fig. 13 are schematic cross-sectional views of the photoelectric conversion device according to the first embodiment during the manufacturing process, and the cross sections in these cross-sectional schematic views are taken along line AA' of the photoelectric conversion device 1000 in Fig. 1.

[0073] Referring to FIG.

[0074] First, a silicon substrate 20 (semiconductor substrate) doped with N-type impurities is prepared. In Fig. 7, the surface corresponding to the light incident surface of the photoelectric conversion device 1000 is shown as the lower side. A trench for element isolation is formed by a known method, and an insulator such as silicon oxide is buried in the trench to form an element isolation region (not shown).

[0075] Next, a first P-type diffusion region 3, a first N-type diffusion region 4, a second P-type diffusion region 5, a third P-type diffusion region 6, a first P-type well 7, a first N-type well 8, a second P-type well 9, a second N-type well 10, and a third P-type well 11 are formed. These can be formed to the desired depth and concentration by a method such as ion implantation using a resist patterned by a method such as photolithography as a mask.

[0076] After the impurity implantation, an annealing process is appropriately performed to activate the implanted impurities. The annealing temperature can be set to, for example, about 800°C to 1100°C.

[0077] At this time, transfer transistors, reset transistors, and selection transistors necessary for driving pixels may be formed in the pixel region, and diffusion regions, gate insulating films, gate electrodes, etc. (not shown) may be formed in the peripheral circuit region to form transistors, resistance elements, etc. necessary for circuit driving.

[0078] Thereafter, as shown in FIG. 8, wiring 16, an interlayer film 17, contact vias (not shown) that connect the wiring 16 to the silicon substrate 20, and vias (not shown) that connect the wirings to each other are formed in sequence on the silicon substrate 20.

[0079] 9 shows the silicon substrate 20 shown in FIG. 8 turned upside down, with a support substrate 2 bonded to the surface opposite the light incident surface. That is, in FIG. 9, the surface of the silicon substrate 20 that corresponds to the light incident surface of the photoelectric conversion device 1000 is shown at the top of the figure. The silicon substrate 20 and the support substrate 2 can be bonded by, for example, plasma activated bonding.

[0080] As shown in FIG. 10, the silicon substrate 20 on the upper side of FIG. 9 is thinned by a method such as back grinding, CMP (Chemical Mechanical Polishing), or wet etching.

[0081] In this case, the film must be thinned to a thickness that allows the formation of potential wells for each well in the peripheral circuit region and sufficient photoelectric conversion of incident light in the photodiode section in the pixel region, for example, to a thickness of 3 μm to 10 μm in the direction perpendicular to the light incident surface.

[0082] A negative fixed charge film 13 is formed on a thinned silicon substrate 20 (FIG. 11).

[0083] The negative fixed charge film 13 can be formed of, for example, aluminum oxide, hafnium oxide, tantalum oxide, titanium oxide, zirconium oxide, etc. However, the material is not limited to these and may be any insulating film capable of serving as a negative fixed charge film, and a plurality of film types may also be used. The negative fixed charge film 13 can be formed by a sputtering method, a CVD (Chemical Vapor Deposition) method, an ALD (Atomic Layer Deposition) method, etc.

[0084] Next, a resist is applied and patterned by a method such as photolithography, etc. At this time, the resist is patterned so that the resist remains in the regions of the second P-type diffusion region 5, the first P-type well 7, the second P-type well 9, and the third P-type well 11, and is removed in the regions of the first N-type well 8 and the second N-type well 10.

[0085] Next, the negative fixed charge film 13 in the regions overlapping the first N-type well 8 and the second N-type well 10 in plan view is removed by a method such as dry etching or wet etching, and the unnecessary resist is stripped off. After the resist is stripped off, the negative fixed charge film 13 remains in the regions overlapping the first P-type well 7, the second P-type well 9, and the third P-type well 11 in plan view.

[0086] Although etching damage occurs in the first N-type well 8 and the second N-type well 10, the resist and the negative fixed charge film 13 can protect the second P-type diffusion region 5, the first P-type well 7, the second P-type well 9, and the third P-type well 11 from etching damage. In addition, an etching stop film having a thickness of, for example, 10 nm or less, can be provided between the negative fixed charge film 13 and the silicon substrate 20 so as not to impair the function of the negative fixed charge film 13 in having a fixed charge. The etching stop film can further reduce etching damage to the second P-type diffusion region 5, the first P-type well 7, the second P-type well 9, and the third P-type well 11.

[0087] A positive fixed charge film 13 is formed above the silicon substrate 20 and the negative fixed charge film 12 (FIG. 12).

[0088] In this embodiment, the positive fixed charge film 13 also functions as an interlayer film on the light incident surface side. However, it is also possible to leave another film, such as a silicon oxide film, that can serve as a positive fixed charge film by patterning it on the regions of the first N-type well 8 and the second N-type well 10, and not use this other film (positive fixed charge film) as an interlayer film.

[0089] A light-shielding film 14 is formed on the positive fixed charge film 13 shown in FIG.

[0090] The material of the light-shielding film can be selected from materials with low light transmittance, such as aluminum, tungsten, copper, etc. The formed light-shielding film 14 is covered with the same material as the positive fixed charge film 13 to form an interlayer film (FIG. 14), and color filters, microlenses, etc. (not shown) are further formed on this interlayer film.

[0091] This manufacturing method reduces etching damage to the peripheral circuitry, which can be a source of noise, and also makes it possible to complete a CMOS image sensor with reduced leakage current between wells.

[0092] (Fifth embodiment) The photoelectric conversion system according to this embodiment will be described with reference to Fig. 15. Fig. 15 is a block diagram showing a schematic configuration of the photoelectric conversion system according to this embodiment.

[0093] The photoelectric conversion devices described in the first to third embodiments are applicable to various photoelectric conversion systems. Examples of applicable photoelectric conversion systems include digital still cameras, digital camcorders, surveillance cameras, copiers, fax machines, mobile phones, vehicle-mounted cameras, and observation satellites. Also included in the photoelectric conversion system is a camera module equipped with an optical system such as a lens and an imaging device. Fig. 15 illustrates a block diagram of a digital still camera as an example of such systems.

[0094] 15 includes an image pickup device 1104, which is an example of a photoelectric conversion device, and a lens 1102 that forms an optical image of a subject on the image pickup device 1104. The system further includes an aperture 1103 that adjusts the amount of light passing through the lens 1102, and a barrier 1101 that protects the lens 1102. The lens 1102 and aperture 1103 form an optical system that focuses light on the image pickup device 1104. The image pickup device 1104 is a photoelectric conversion device according to any of the above embodiments, and converts the optical image formed by the lens 1102 into an electrical signal.

[0095] The photoelectric conversion system also includes a signal processing unit 1107, which is an image generation unit that generates an image by processing an output signal output from the imaging device 1104. The signal processing unit 1107 performs various corrections and compressions as necessary to output image data. The signal processing unit 1107 may be formed on the same semiconductor substrate on which the imaging device 1104 is provided, or may be formed on a semiconductor substrate separate from the imaging device 1104.

[0096] The photoelectric conversion system further includes a memory unit 1110 for temporarily storing image data, and an external interface unit (external I / F unit) 1113 for communicating with an external computer or the like. The photoelectric conversion system further includes a recording medium 1112 such as a semiconductor memory for recording or reading out imaging data, and a recording medium control interface unit (recording medium control I / F unit) 1111 for recording or reading out data from the recording medium 1112. The recording medium 1112 may be built into the photoelectric conversion system or may be removable.

[0097] The photoelectric conversion system further includes an overall control / calculation unit 1109 that performs various calculations and controls the entire digital still camera, and a timing generation unit 1108 that outputs various timing signals to the image capture device 1104 and the signal processing unit 1107. Here, timing signals and the like may be input from outside, and the photoelectric conversion system only needs to include at least the image capture device 1104 and the signal processing unit 1107 that processes the output signal output from the image capture device 1104.

[0098] The imaging device 1104 outputs an imaging signal to the signal processing unit 1107. The signal processing unit 1107 performs predetermined signal processing on the imaging signal output from the imaging device 1104 and outputs image data. The signal processing unit 1107 generates an image using the imaging signal.

[0099] As described above, according to this embodiment, it is possible to realize a photoelectric conversion system to which the photoelectric conversion device (imaging device) according to any one of the above embodiments is applied.

[0100] (Sixth embodiment) The photoelectric conversion system and the moving object of this embodiment will be described with reference to Fig. 16. Fig. 16 is a diagram showing the configuration of the photoelectric conversion system and the moving object of this embodiment.

[0101] FIG. 16(a) illustrates an example of a photoelectric conversion system related to an in-vehicle camera. The photoelectric conversion system 300 includes an image capture device 310. The image capture device 310 is the photoelectric conversion device (image capture device) described in any of the above embodiments. The photoelectric conversion system 300 includes an image processing unit 312 that performs image processing on multiple pieces of image data acquired by the image capture device 310, and a parallax acquisition unit 314 that calculates parallax (phase difference between parallax images) from the multiple pieces of image data acquired by the photoelectric conversion system 300. The photoelectric conversion system 300 also includes a distance acquisition unit 316 that calculates the distance to an object based on the calculated parallax, and a collision determination unit 318 that determines whether or not there is a possibility of a collision based on the calculated distance. Here, the parallax acquisition unit 314 and the distance acquisition unit 316 are examples of distance information acquisition means that acquire information about the distance to the object. That is, the distance information includes information about the parallax, the defocus amount, the distance to the object, etc. The collision determination unit 318 may determine the possibility of a collision using any of this distance information. The distance information acquisition means may be realized by dedicated hardware, a software module, a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or a combination thereof.

[0102] The photoelectric conversion system 300 is connected to a vehicle information acquisition device 320 and can acquire vehicle information such as vehicle speed, yaw rate, and steering angle. The photoelectric conversion system 300 is also connected to a control ECU 330, which is a control unit that outputs a control signal to generate a braking force for the vehicle based on the determination result of the collision determination unit 318. The photoelectric conversion system 300 is also connected to an alarm device 340 that issues an alarm to the driver based on the determination result of the collision determination unit 318. For example, if the determination result of the collision determination unit 318 indicates a high possibility of a collision, the control ECU 330 performs vehicle control to avoid the collision and mitigate damage by applying the brakes, releasing the accelerator, suppressing engine output, etc. The alarm device 340 warns the user by sounding an alarm, displaying alarm information on a screen such as a car navigation system, or vibrating the seat belt or steering wheel.

[0103] In this embodiment, the surroundings of the vehicle, for example, the front or rear, are imaged by the photoelectric conversion system 300. Fig. 16(b) shows the photoelectric conversion system when imaging the area in front of the vehicle (imaging range 350). The vehicle information acquisition device 320 sends instructions to the photoelectric conversion system 300 or the imaging device 310. This configuration can further improve the accuracy of distance measurement.

[0104] Although the above describes an example of control to prevent collision with other vehicles, the present invention can also be applied to control of automatic driving by following other vehicles, and control of automatic driving to prevent deviation from a lane. Furthermore, the photoelectric conversion system is not limited to vehicles such as the subject vehicle, but can be applied to moving bodies (moving devices) such as ships, aircraft, and industrial robots. In addition, the present invention can be applied not only to moving bodies but also to a wide range of devices that use object recognition, such as intelligent transport systems (ITS).

[0105] [Modified embodiment] The present invention is not limited to the above-described embodiment, and various modifications are possible.

[0106] For example, an example in which part of the configuration of any one of the embodiments is added to another embodiment, or an example in which part of the configuration of another embodiment is replaced with another embodiment, is also included in the embodiments of the present invention.

[0107] Although the description of each embodiment has been given using as an example a photoelectric conversion device in which a substrate having a semiconductor substrate and a support substrate are stacked, the application of the present invention is not limited to such a stacked structure photoelectric conversion device. The present invention can also be applied to, for example, a photoelectric conversion device that does not have a support substrate, or a photoelectric conversion device in which three substrates are stacked: a substrate having a semiconductor substrate, a support substrate, and a substrate on which a signal processing unit, etc., is formed.

[0108] Furthermore, the photoelectric conversion systems shown in the fifth and sixth embodiments are examples of photoelectric conversion systems to which the photoelectric conversion device can be applied, and the photoelectric conversion systems to which the photoelectric conversion device of the present invention can be applied are not limited to the configurations shown in Figures 15 and 16.

[0109] It should be noted that the above-described embodiments are merely examples of specific embodiments for carrying out the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be carried out in various forms without departing from its technical concept or main features. [Explanation of symbols]

[0110] 1. Substrate with semiconductor substrate 8 N-type diffusion region 9 P-type diffusion region 12 Fixed charge membrane with negative fixed charge 13 Fixed charge film with positive fixed charge

Claims

1. A photoelectric conversion device having a semiconductor substrate, the photoelectric conversion device having a light incident surface, the semiconductor substrate has a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region; the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region; A photoelectric conversion device, characterized in that the fixed charge film having negative fixed charges and the fixed charge film having positive fixed charges are aligned in a direction parallel to the light incident surface.

2. A photoelectric conversion device having a semiconductor substrate, the photoelectric conversion device having a light incident surface, the semiconductor substrate has a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region at different positions in a plan view from the light incident surface side, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region; the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region; In the peripheral circuit region, the fixed charge film having the negative fixed charge extends from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region, and the fixed charge film having the positive fixed charge does not extend from the light incident surface side of the N-type semiconductor region to the light incident surface side of the P-type semiconductor region or extends only to the light incident surface side of a part of the P-type semiconductor region, or a fixed charge film having a positive fixed charge extending from the light incident surface side of the N-type semiconductor region to the light incident surface side of the P-type semiconductor region, and a fixed charge film having a negative fixed charge not extending from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or extending only to the light incident surface side of a portion of the N-type semiconductor region.

3. A photoelectric conversion device having a semiconductor substrate, the photoelectric conversion device having a light incident surface, the semiconductor substrate has a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region at different positions in a plan view from the light incident surface side, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region; the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region; a fixed charge film having a negative fixed charge that does not extend from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or that extends only to the light incident surface side of a portion of the P-type semiconductor region; or a fixed charge film having a negative fixed charge that does not extend from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or that extends only to the light incident surface side of a portion of the N-type semiconductor region.

4. the N-type semiconductor region includes a first N-type semiconductor region and a second N-type semiconductor region; the first P-type semiconductor region is disposed between the first N-type semiconductor region and the second N-type semiconductor region; 4. The photoelectric conversion device according to claim 1, wherein the first N-type semiconductor region and the second N-type semiconductor region are separated by a region including a fixed charge film having the negative fixed charge, the fixed charge film overlapping the first P-type semiconductor region in a planar view from the light incident surface side.

5. A photoelectric conversion device having a semiconductor substrate, the photoelectric conversion device having a light incident surface, the semiconductor substrate has a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the N-type semiconductor region includes a first N-type semiconductor region and a second N-type semiconductor region; the P-type semiconductor region is disposed between the first N-type semiconductor region and the second N-type semiconductor region; A photoelectric conversion device, characterized in that the fixed charge film having negative fixed charges and the fixed charge film having positive fixed charges are aligned in a direction parallel to the light incident surface.

6. A photoelectric conversion device having a semiconductor substrate, the photoelectric conversion device having a light incident surface, the semiconductor substrate has a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region at different positions in a plan view from the light incident surface side, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the N-type semiconductor region includes a first N-type semiconductor region and a second N-type semiconductor region; the P-type semiconductor region is disposed between the first N-type semiconductor region and the second N-type semiconductor region; In the peripheral circuit region, the fixed charge film having the negative fixed charge extends from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region, and the fixed charge film having the positive fixed charge does not extend from the light incident surface side of the N-type semiconductor region to the light incident surface side of the P-type semiconductor region or extends only to the light incident surface side of a part of the P-type semiconductor region, or a fixed charge film having a positive fixed charge extending from the light incident surface side of the N-type semiconductor region to the light incident surface side of the P-type semiconductor region, and a fixed charge film having a negative fixed charge not extending from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or extending only to the light incident surface side of a portion of the N-type semiconductor region.

7. A photoelectric conversion device having a semiconductor substrate, the photoelectric conversion device having a light incident surface, the semiconductor substrate has a photoelectric conversion unit and a peripheral circuit region that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region at different positions in a plan view from the light incident surface side, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the N-type semiconductor region includes a first N-type semiconductor region and a second N-type semiconductor region; the P-type semiconductor region is disposed between the first N-type semiconductor region and the second N-type semiconductor region; a fixed charge film having a negative fixed charge that does not extend from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or that extends only to the light incident surface side of a portion of the P-type semiconductor region; or a fixed charge film having a negative fixed charge that does not extend from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or that extends only to the light incident surface side of a portion of the N-type semiconductor region.

8. the P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region; the first N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region; 8. The photoelectric conversion device according to claim 5, wherein the first P-type semiconductor region and the second P-type semiconductor region are separated by a region including a fixed charge film having the positive fixed charge, the fixed charge film overlapping the first N-type semiconductor region in a planar view from the light incident surface side.

9. the photoelectric conversion unit includes an electron accumulation type photodiode, 9. The photoelectric conversion device according to claim 1, wherein a fixed charge film having negative fixed charges is formed on the light incident surface side of the photoelectric conversion section.

10. the photoelectric conversion unit includes a hole accumulation photodiode, 9. The photoelectric conversion device according to claim 1, wherein a fixed charge film having positive fixed charges is formed on the light incident surface side of the photoelectric conversion section.

11. 11. The photoelectric conversion device according to claim 1, wherein the semiconductor substrate has a thickness of 3 [mu]m or more and 10 [mu]m or less in a direction perpendicular to the light incident surface.

12. 12. The photoelectric conversion device according to claim 1, further comprising a substrate stacked on the semiconductor substrate and including a transistor for reading out a signal generated in the photoelectric conversion portion.

13. 13. The photoelectric conversion device according to claim 1, wherein, in a planar view from the light incident surface side, the hole accumulation layer is arranged at a position overlapping the P-type semiconductor region, and, in a planar view from the light incident surface side, the electron accumulation layer is arranged at a position overlapping the N-type semiconductor region.

14. 14. The photoelectric conversion device according to claim 1, wherein the hole accumulation layer is electrically connected to the P-type semiconductor region, and the electron accumulation layer is electrically connected to the N-type semiconductor region.

15. 15. The photoelectric conversion device according to claim 1, wherein the hole accumulation layer is in contact with the P-type semiconductor region, and the electron accumulation layer is in contact with the N-type semiconductor region.

16. The photoelectric conversion device according to any one of claims 1 to 15, a signal processing unit that generates an image using a signal output from the photoelectric conversion device.

17. A moving object comprising the photoelectric conversion device according to any one of claims 1 to 15, A moving body comprising a control unit that controls the movement of the moving body using a signal output from the photoelectric conversion device.

18. a photoelectric conversion unit and a peripheral circuit area that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region, a fixed charge film having negative fixed charges on the light incident surface side in a region overlapping the P-type semiconductor region in a plan view from the light incident surface side; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region; the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region; A semiconductor substrate, characterized in that the fixed charge film having negative fixed charges and the fixed charge film having positive fixed charges are aligned in a direction parallel to the light incident surface.

19. a photoelectric conversion unit and a peripheral circuit area that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region at different positions in a plan view from the light incident surface side, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the P-type semiconductor region includes a first P-type semiconductor region and a second P-type semiconductor region; the N-type semiconductor region is disposed between the first P-type semiconductor region and the second P-type semiconductor region; the peripheral circuit region has one or both of a configuration in which a fixed charge film having the positive fixed charge does not extend from the light incident surface side of the N-type semiconductor region to the light incident surface side of the P-type semiconductor region or extends only to the light incident surface side of a portion of the P-type semiconductor region, and a configuration in which a fixed charge film having the negative fixed charge does not extend from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or extends only to the light incident surface side of a portion of the N-type semiconductor region.

20. a photoelectric conversion unit and a peripheral circuit area that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region, a fixed charge film having negative fixed charges on the light incident surface side in a region overlapping the P-type semiconductor region in a plan view from the light incident surface side; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the N-type semiconductor region includes a first N-type semiconductor region and a second N-type semiconductor region; the P-type semiconductor region is disposed between the first N-type semiconductor region and the second N-type semiconductor region; A semiconductor substrate, characterized in that the fixed charge film having negative fixed charges and the fixed charge film having positive fixed charges are aligned in a direction parallel to the light incident surface.

21. a photoelectric conversion unit and a peripheral circuit area that processes signals generated by the photoelectric conversion unit; the peripheral circuit region has a P-type semiconductor region and an N-type semiconductor region at different positions in a plan view from the light incident surface side, a fixed charge film having negative fixed charges on the light incident surface side of the P-type semiconductor region; a fixed charge film having positive fixed charges on the light incident surface side of the N-type semiconductor region; the fixed charge film having negative fixed charges forms a hole accumulation layer on a surface of the P-type semiconductor region facing the fixed charge film having negative fixed charges, the fixed charge film having positive fixed charges forms an electron accumulation layer on a surface of the N-type semiconductor region facing the fixed charge film having positive fixed charges; the N-type semiconductor region includes a first N-type semiconductor region and a second N-type semiconductor region; the P-type semiconductor region is disposed between the first N-type semiconductor region and the second N-type semiconductor region; the peripheral circuit region has one or both of a configuration in which a fixed charge film having the positive fixed charge does not extend from the light incident surface side of the N-type semiconductor region to the light incident surface side of the P-type semiconductor region or extends only to the light incident surface side of a portion of the P-type semiconductor region, and a configuration in which a fixed charge film having the negative fixed charge does not extend from the light incident surface side of the P-type semiconductor region to the light incident surface side of the N-type semiconductor region or extends only to the light incident surface side of a portion of the N-type semiconductor region.

Images