Single photon avalanche diode device and preparation method thereof

Abstract

The invention relates to the technical field of integrated circuits, in particular to a single photon avalanche diode device and a preparation method thereof. The single photon avalanche diode device includes: a substrate; the epitaxial layer is located on one side of the substrate, the epitaxial layer is provided with a plurality of pixel regions, at least one pixel region comprises a first doped region, a second doped region and a third doped region which are continuously arranged in the direction from the side, away from the substrate, of the epitaxial layer to the substrate, the second doped region is located between the first doped region and the third doped region, and the third doped region is located between the first doped region and the third doped region. The first doped region and the third doped region have a first doping type, and the second doped region has a second doping type. A first doped region, a second doped region and a third doped region are sequentially arranged in an epitaxial layer, so that double avalanche regions are formed in a single-photon avalanche diode device. At the moment, when light enters the single-photon avalanche diode device, a large-scale avalanche effect can be triggered, and then a strong electric signal can be generated, so that the photon detection efficiency is improved.

Description

Technical Field

[0001] The present application relates to the field of integrated circuit technologies, and particularly to a single-photon avalanche diode device and a preparation method thereof. Background Art

[0002] A single-photon avalanche diode (SPAD) is a highly sensitive photodetector device with single-photon detection capabilities. A single-photon avalanche diode is a PN junction operating under reverse bias, and the operating voltage is higher than the breakdown voltage, in the Geiger mode. When no photons are incident, the SPAD is in a steady state, and a strong electric field will be formed in the depletion region of the device, but no free carriers will be ionized. When a photon is incident and absorbed by the detector, an avalanche effect can be triggered, generating an electrical signal that can be detected.

[0003] Currently, the application spectra of single-photon avalanche diode devices are mainly infrared light at 905 nm and 940 nm. However, the penetration distance of this infrared light in silicon wafers is long, resulting in limited ability of single-photon avalanche diode devices to absorb infrared light, and relatively low photon detection efficiency. Summary of the Invention

[0004] Based on this, it is necessary to provide a single-photon avalanche diode device for the problem of relatively low detection efficiency of single-photon avalanche diode devices in the prior art.

[0005] To achieve the above object, on the one hand, a single-photon avalanche diode device is provided, including:

[0006] A substrate;

[0007] An epitaxial layer, located on one side of the substrate, the epitaxial layer having a plurality of pixel regions, and in the direction from the side of the epitaxial layer away from the substrate towards the substrate, at least one of the pixel regions includes a first doping region, a second doping region, and a third doping region arranged continuously, the second doping region being located between the first doping region and the third doping region, and the first doping region and the third doping region having a first doping type, and the second doping region having a second doping type.

[0008] In one embodiment, the orthographic projection of the first doping region on the substrate overlaps with the orthographic projection of the third doping region on the substrate, and / or, in the thickness direction of the epitaxial layer, the size of the first doping region is the same as the size of the third doping region.

[0009] In one embodiment, the doping concentration of the first doped region is the same as that of the third doped region, and / or the doping ions of the first doped region are the same as those of the third doped region.

[0010] In one embodiment, in a direction parallel to the substrate, the size of the second doped region is larger than that of the first doped region, and / or in a direction parallel to the substrate, the size of the second doped region is larger than that of the third doped region.

[0011] In one embodiment, the single-photon avalanche diode device further includes:

[0012] A deep trench isolation structure extending from the surface of the epitaxial layer away from the substrate into the epitaxial layer, and the deep trench isolation structure surrounds the pixel region.

[0013] In one embodiment, the deep trench isolation structure protrudes from the surface of the epitaxial layer away from the substrate.

[0014] In one embodiment, the deep trench isolation structure is electrically connected to the first doped region.

[0015] In one embodiment, the single-photon avalanche diode device further includes:

[0016] A first well region surrounding the first doped region and isolated from the first doped region, the first well region having a first doping type, and the deep trench isolation structure, the first doped region, and the first well region are electrically connected;

[0017] And / or, the single-photon avalanche diode device further includes:

[0018] A second well region surrounding the first doped region and isolated from the first doped region, the second well region having a second doping type, and in a direction approaching the substrate from the side of the epitaxial layer away from the substrate, the second well region extends into the epitaxial layer via the second doped region, and the second well region is located between the first doped region and the first well region.

[0019] In one embodiment, the deep trench isolation structure has a first distance from the substrate, the third doped region has a second distance from the substrate, and the first distance is less than the second distance.

[0020] On the one hand, a method for manufacturing a single-photon avalanche diode device is provided, and the method for manufacturing the single-photon avalanche diode device includes the following steps:

[0021] Provide a substrate;

[0022] An epitaxial material layer is formed on one side of the substrate. The epitaxial material layer has deep trenches that extend from the side of the epitaxial material layer away from the substrate into the interior of the epitaxial material layer.

[0023] The deep trenches are filled to form a deep trench isolation structure. The deep trench isolation structure encloses to form a pixel region, and the epitaxial material layer forms an epitaxial layer.

[0024] A first doped region, a second doped region, and a third doped region are formed in the pixel region. In the direction from the side of the epitaxial layer away from the substrate towards the substrate, the first doped region, the second doped region, and the third doped region are arranged in sequence, and the first doped region and the third doped region have a first doping type, while the second doped region has a second doping type.

[0025] The single-photon avalanche diode device and its manufacturing method of the present application have the following beneficial effects: First, by sequentially arranging a first doped region, a second doped region, and a third doped region in the epitaxial layer, a double avalanche region is formed in the single-photon avalanche diode device. At this time, when light enters the single-photon avalanche diode device, a large-scale avalanche effect can be triggered, and then a strong electrical signal can be generated, thereby increasing the photon detection efficiency. Second, in the present application, the first doped region, the second doped region, and the third doped region are continuously arranged, and the first doped region and the third doped region can be the same in terms of size, doping concentration, ion type, etc., so as to ensure that the performance of the upper and lower two avalanche regions is consistent, further increasing the photon detection efficiency. In one embodiment of the present application, by forming a deep trench isolation structure surrounding the pixel region, the deep trench isolation structure isolates adjacent pixel regions, thereby preventing crosstalk between adjacent pixel regions. At the same time, the deep trench isolation structure can be electrically connected to the first doped region, so that the voltages of the first doped region and the third doped region are the same, and then the electrical properties of the upper and lower two avalanche regions are the same, ensuring a further increase in the photon detection efficiency. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application or in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0027] Figure 1 It is a schematic structural diagram of a single-photon avalanche diode device provided in an embodiment;

[0028] Figure 2 It is a top view of a pixel region provided in an embodiment;

[0029] Figure 3 Schematic diagram of a pixel array provided in one embodiment;

[0030] Figure 4 Schematic diagram of the structure of a single - photon avalanche diode device provided in another embodiment;

[0031] Figure 5 Schematic diagram of a circuit provided in one embodiment;

[0032] Figure 6 Schematic diagram of the avalanche intensity of TCAD simulation provided in one embodiment;

[0033] Figure 7 Schematic diagram of the preparation process of a single - photon avalanche diode device provided in one embodiment.

[0034] Explanation of reference numerals: Single - photon avalanche diode device - 100; Substrate - 110; Epitaxial layer - 120; Pixel region - 121; First doped region - 1211; Second doped region - 1212; Third doped region - 1213; Deep trench isolation structure - 130; Shallow trench isolation structure - 131; First highly doped region - 140; Second highly doped region - 141; Third highly doped region - 142; Anode - 150; Cathode - 151; Second lead - out structure - 152; First well region - 160; Second well region - 161; Metal structure - 170.

[0035] To better describe and illustrate the embodiments and / or examples of the inventions disclosed herein, one or more drawings may be referred to. Additional details or examples used to describe the drawings should not be considered as limiting the scope of any of the disclosed inventions, the currently described embodiments and / or examples, and the currently understood best mode of these inventions. Detailed embodiments

[0036] To facilitate the understanding of the present application, the present application will be described more comprehensively below with reference to the relevant drawings. Preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the description of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0038] In various embodiments, unless otherwise clearly specified and defined, terms such as "install", "connect", "link", "fix", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in various embodiments can be understood according to specific circumstances.

[0039] It should be understood that when an element or layer is referred to as "on", "adjacent to", "connected to", or "coupled to" another element or layer, it can be directly on, adjacent to, connected, or coupled to the other element or layer, or there can be intervening elements or layers. In contrast, when an element is referred to as "directly on", "directly adjacent to", "directly connected to", or "directly coupled to" another element or layer, there are no intervening elements or layers. It should be understood that although terms such as first, second, third, etc. may be used to describe various elements, components, regions, layers, doping types, and / or parts, these elements, components, regions, layers, doping types, and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, doping type, or part from another element, component, region, layer, doping type, or part. Therefore, without departing from the teachings of this embodiment, the first element, component, region, layer, doping type, or part discussed below can be referred to as the second element, component, region, layer, or part.

[0040] Spatial relationship terms such as "under", "below", "lower", "beneath", "above", "upper", etc. can be used here to describe the relationship between an element or feature shown in the figure and other elements or features. It should be understood that in addition to the orientation shown in the figure, spatial relationship terms also include different orientations of the device during use and operation. For example, if the device in the figure is flipped, an element or feature described as "under" or "beneath" or "below" another element or feature will be oriented "on" the other element or feature. Therefore, the exemplary terms "under" and "below" can include both the upper and lower orientations. In addition, the device can also have other orientations (such as rotating 90 degrees or other orientations), and the spatial descriptors used here are accordingly interpreted.

[0041] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that when the terms "comprising" and / or "including" are used in this specification, the presence of the stated features, integers, steps, operations, elements and / or components can be ascertained, but one or more other features, integers, steps, operations, elements, components and / or groups thereof are not precluded from being present or added. Also, as used herein, the term "and / or" includes any and all combinations of the associated listed items.

[0042] Embodiments of the present application are described herein with reference to cross-sectional views that are ideal embodiments of the present application, and variations in the shapes shown can be expected due to, for example, manufacturing techniques and / or tolerances. Accordingly, embodiments of the present application should not be limited to the specific shapes of the regions shown herein, but include shape deviations due to, for example, manufacturing techniques. The regions shown in the figures are substantially schematic, and their shapes do not represent the actual shapes of the regions of the device and do not limit the scope of the embodiments of the present application.

[0043] In one embodiment, referring to Figures 1 to 4 , a single-photon avalanche diode device 100 is provided. The single-photon avalanche diode device 100 may include a substrate 110 and an epitaxial layer 120.

[0044] The substrate 110 may be formed of a semiconductor material, an insulating material, or any combination thereof. The substrate 110 may be a single-layer structure or a multi-layer structure. For example, the substrate 110 may be a substrate such as a silicon (Si) substrate, a silicon germanium (SiGe) substrate, a silicon germanium carbon (SiGeC) substrate, a silicon carbide (SiC) substrate, a gallium arsenide (GaAs) substrate, an indium arsenide (InAs) substrate, an indium phosphide (InP) substrate, or other III / V semiconductor substrates or II / VI semiconductor substrates. Or, for another example, the substrate 110 may be a layered substrate including, for example, Si / SiGe, Si / SiC, silicon on insulator (SOI), or silicon germanium on insulator. Therefore, the type of the substrate 110 should not limit the protection scope of the present application.

[0045] The epitaxial layer 120 is located on one side of the substrate 110. The epitaxial layer 120 may include a P-type epitaxial layer 120 or an N-type epitaxial layer 120. As an example, a layer of P-type doped semiconductor material may be formed on the substrate 110 by epitaxial growth technology to form the P-type epitaxial layer 120.

[0046] Referring to Figure 3 , the epitaxial layer 120 may have a plurality of pixel regions 121 arranged at intervals. As an example, the plurality of pixel regions 121 may be arranged in an array form.

[0047] On the side of the self-epitaxial layer 120 away from the substrate 110 and in the direction close to the substrate 110, at least one pixel region 121 includes a first doped region 1211, a second doped region 1212, and a third doped region 1213 that are continuously arranged. The first doped region 1211 can be close to the surface of the epitaxial layer 120 away from the substrate 110. The second doped region 1212 is located between the first doped region 1211 and the third doped region 1213, and the first doped region 1211 and the third doped region 1213 have a first doping type, while the second doped region 1212 has a second doping type. As an example, the first doped region 1211 and the third doped region 1213 can be P-type doped, and the second doped region 1212 can be N-type doped. Of course, the first doped region 1211 and the third doped region 1213 can be N-type doped, and the second doped region 1212 can be P-type doped. Further, at this time, the epitaxial layer 120 can have a first doping type. Of course, in the actual doping process, in the thickness direction of the epitaxial layer 120, there can be an intersection between the first doped region 1211 and the second doped region 1212, and between the second doped region 1212 and the third doped region 1213.

[0048] At this time, the first doped region 1211, the second doped region 1212, and the third doped region 1213 together form a double avalanche region. Specifically, the part of the first doped region 1211 close to the second doped region 1212 and the part of the second doped region 1212 close to the first doped region 1211 form a first avalanche region (for example, Figure 1 the A region in), the part of the third doped region 1213 close to the second doped region 1212 and the part of the second doped region 1212 close to the third doped region 1213 form a second avalanche region (for example, Figure 1 the B region in). It can be understood that in this embodiment, the single-photon avalanche diode device 100 has two avalanche regions, upper and lower.

[0049] In a possible instance, the orthographic projection of the first doped region 1211 on the substrate 110 overlaps with the orthographic projection of the third doped region 1213 on the substrate 110, and / or, in the thickness direction of the epitaxial layer 120, the size of the first doped region 1211 is the same as the size of the third doped region 1213. In another possible instance, the doping concentration of the first doped region 1211 is the same as the doping concentration of the third doped region 1213, and / or, the doping ions of the first doped region 1211 are the same as the doping ions of the third doped region 1213. It can be understood that the first doped region 1211 and the third doped region 1213 can be the same in terms of size, doping concentration, ion type, etc. This embodiment does not limit the specific size, doping concentration, and ion type of the first doped region 1211 and the third doped region 1213.

[0050] Furthermore, in a direction parallel to the substrate 110, the size of the second doping region 1212 is larger than the size of the first doping region 1211, and / or, in a direction parallel to the substrate 110, the size of the second doping region 1212 is larger than the size of the third doping region 1213. This is conducive to the preparation of a double avalanche region.

[0051] In this embodiment, first, by sequentially setting the first doping region 1211, the second doping region 1212 and the third doping region 1213 in the epitaxial layer 120, a double avalanche region is formed in the single-photon avalanche diode device 100. At this time, when light enters the single-photon avalanche diode device 100, a larger-scale avalanche effect can be triggered, and a stronger electrical signal can be generated, thereby increasing the photon detection efficiency. Secondly, in this embodiment, the first doping region 1211, the second doping region 1212 and the third doping region 1213 are continuously arranged, and the first doping region 1211 and the third doping region 1213 can be consistent in terms of size, doping concentration, ion type, etc., thereby ensuring that the performance of the upper and lower avalanche regions is consistent, further increasing the photon detection efficiency.

[0052] In one embodiment, see Figure 1 The single-photon avalanche diode device 100 further includes a deep trench isolation structure 130 (Deep Trench Isolation, DTI).

[0053] The deep trench isolation structure 130 extends from the surface of the epitaxial layer 120 away from the substrate 110 toward the interior of the epitaxial layer 120, and the deep trench isolation structure 130 surrounds the pixel region 121. As an example, when fabricating the single-photon avalanche diode device 100, the deep trench isolation structure 130 can be fabricated first, and then the pixel region 121 is formed, thereby preventing damage to the pixel region 121 during etching and other processes.

[0054] For example, in the top view of the single-photon avalanche diode device 100, the deep trench isolation structure 130 may be rectangular, forming a unit pixel. A pixel region 121 is formed inside each rectangle, thereby facilitating the rapid formation of a pixel array (e.g., Figure 3 Also, see Figure 2 The first doping region 1211 , the second doping region 1212 and the third doping region 1213 in the pixel region 121 may be circular or annular in shape, thereby avoiding tip discharge.

[0055] In this embodiment, a deep trench isolation structure 130 is formed surrounding the pixel region 121 , so that the deep trench isolation structure 130 isolates adjacent pixel regions 121 , thereby preventing crosstalk between adjacent pixel regions 121 .

[0056] In a possible example, please refer to Figure 1 , the deep trench isolation structure 130 can be electrically connected to the first doped region 1211, so that the voltages of the first doped region 1211 and the third doped region 1213 are the same, and then the electrical properties of the upper and lower avalanche regions are the same, ensuring that the photon detection efficiency is further increased. Further, the deep trench isolation structure 130 can protrude from the surface of the epitaxial layer 120 away from the substrate 110, so as to facilitate the setting of the first lead-out structure at one end of the deep trench isolation structure 130 away from the substrate 110. Moreover, the deep trench isolation structure 130 and the substrate 110 have a first distance ( Figure 1 H1 in Figure 1 ), the third doped region 1213 and the substrate 110 have a second distance (

[0057] H2 in Figure 2 ), and the first distance is less than the second distance, which is beneficial for the deep trench isolation structure 130 to better control the voltage of the third doped region 1213, thereby further ensuring the consistency of the electrical properties of the upper and lower avalanche regions.

[0058] At the outermost periphery of the pixel matrix, please refer to Figure 1 , the single-photon avalanche diode device 100 further includes a first well region 160 (for example, PWH). The first well region 160 can surround the first doped region 1211 and is arranged separately from the first doped region 1211. The first well region 160 has a first doping type, and the deep trench isolation structure 130, the first doped region 1211, and the first well region 160 are electrically connected.

[0059] Similar to the first doping region 1211, a second highly doped region 141 may be provided on one side of the first well region 160 close to the surface of the epitaxial layer 120. The ion concentration in the second highly doped region 141 may be greater than that in other regions of the first well region 160. At the same time, a second lead-out structure 152 may be provided on the epitaxial layer 120, which is conducive to electrically connecting the deep trench isolation structure 130, the first doping region 1211, and the first well region 160. In addition, a shallow trench isolation structure 131 (Shallow Trench Isolation, STI) or the like may be provided at the first well region 160. The first well region 160 may extend from the shallow trench isolation structure 131 into the interior of the epitaxial layer 120. The shallow trench isolation structure 131 and the first well region 160 together function to isolate the pixel matrix region from the external region (Guardring), thereby preventing external circuit noise from interfering with internal pixels.

[0060] In yet another possible example, refer to Figure 4 , the single-photon avalanche diode device 100 further includes a second well region 161. The second well region 161 may surround the first doping region 1211 and be disposed separately from the first doping region 1211. At the same time, the second well region 161 is located between the first doping region 1211 and the first well region 160. The second well region 161 has a second doping type. In addition, in the direction from the side of the epitaxial layer 120 away from the substrate 110 towards the substrate 110, the second well region 161 extends into the interior of the epitaxial layer 120 via the second doping region 1212.

[0061] Furthermore, a third highly doped region 142 may be provided on one side of the second well region 161 close to the surface of the epitaxial layer 120. The ion concentration in the third highly doped region 142 may be greater than that in other regions of the second well region 161. At the same time, a third lead-out structure (for example, the cathode 151) may be provided on the epitaxial layer 120. A metal structure 170 may be provided between the third lead-out structure and the epitaxial layer 120, thereby increasing the connection area of the cathode 151. The material of the metal structure 170 may include metal materials such as cobalt (Co), nickel (Ni), titanium (Ti), tungsten (W), tantalum (Ta), tantalum titanium TaTi, tungsten nitride (WN), copper (Cu), and aluminum (Al).

[0062] In this embodiment, the cathode 151 and the anode 150 are respectively used to apply voltages to the first doping region 1211, the second doping region 1212, and the third doping region 1213, so that the second doping region 1212 forms two avalanche diodes (Spad1 and Spad2) with the second doping region 1212 and the third doping region 1213 respectively. In one possible example, refer to Figure 5, the anode 150 can be grounded (i.e., the voltage of the anode 150 is 0V), and the cathode 151 can be electrically connected to the connection V spad . When V spad voltage is higher than the breakdown voltages (V breakdown ) of the two avalanche diodes, avalanches will occur in the avalanche diodes, and the optically generated carriers will increase rapidly. Through the quench circuit, the optically generated carriers can be converted into photocurrent. After that, through the resistor R, it is converted into the voltage Vc, and then output Vout through the inverter. Since the two avalanche diodes are in parallel, the amplification effect is doubled, thus effectively improving the photoelectric detection effect of the entire device.

[0063] Please refer to Figure 6 , the figure shows a schematic diagram of TCAD (Technology Computer-Aided Design) simulation using the single-photon avalanche diode device 100 (double avalanche region) provided in one or more embodiments of this specification. Among them, Figure 6 Figure A in Figure 6 is the contour distribution diagram (Contour) of the avalanche intensity. It can be seen from Figure 6 Figure A in Figure 6 that both avalanche regions ( Figure 6 region A' and region B' in Figure A of Figure 6 ) in Figure A have high avalanche field strengths.

[0064] In one embodiment, the single-photon avalanche diode device 100 provided in one or more embodiments of this specification can be a front-side illumination (FSI) single-photon avalanche diode device or a back-side illumination (BSI) single-photon avalanche diode device.

[0065] Preferably, when the single-photon avalanche diode device 100 is a front-side illumination single-photon avalanche diode device, the incident light enters from one side of the first doping region 1211. At this time, part of the carriers are located in the avalanche region close to the first doping region 1211, and part of the carriers are located in the avalanche region close to the third doping region 1213. At this time, a large number of carriers can be collected in both the upper and lower avalanche regions, thus effectively improving the photoelectric detection effect of the entire device.

[0066] In addition, it should be noted that the inventor's research found that since the size (e.g., thickness, volume, etc.) of the epitaxial layer above the first doping region 1211 is much smaller than the size (e.g., thickness, volume, etc.) of the epitaxial layer below the third doping region 1213, the number of carriers in the two avalanche regions is inconsistent. Specifically, the number of carriers in the avalanche region near the first doping region 1211 (e.g., the A' region in FIG. A of Figure 6 ) is less than the number of carriers in the avalanche region near the third doping region 1213 (e.g., the B' region in FIG. A of Figure 6 ), which further makes the avalanche intensities of the two avalanche regions inconsistent. Preferably, when the single-photon avalanche diode device 100 is a front-illuminated single-photon avalanche diode device, the avalanche region near the first doping region 1211 has a small size but is closer to the incident light, and the avalanche region near the third doping region 1213 has a larger size but is far from the incident light. This makes the number of carriers in the two avalanche regions inconsistent but relatively close, so as to obtain a single-photon avalanche diode device 100 with better photoelectric detection effect. When the single-photon avalanche diode device 100 is a back-illuminated single-photon avalanche diode device, the incident light enters from the avalanche region near the third doping region 1213. At this time, the difference in the number of carriers in the two avalanche regions is large, and it is not helpful for improving the performance of the single-photon avalanche diode device 100.

[0067] In one embodiment, the single-photon avalanche diode device 100 provided in one or more embodiments of this specification can be applied to devices in fields such as lidar, ToF sensors, quantum communication and quantum computing, high-speed optical communication and free-space optical communication, and biomedical imaging.

[0068] Based on the same inventive concept, please refer to Figure 7 , in one embodiment, a method for manufacturing a single-photon avalanche diode device 100 is provided. The method for manufacturing the single-photon avalanche diode device 100 may include the following steps:

[0069] Step S100: Provide a substrate 110.

[0070] Step S200: Form an epitaxial material layer on one side of the substrate 110. The epitaxial material layer has deep trenches, and the deep trenches extend from the side of the epitaxial material layer away from the substrate 100 to the inside of the epitaxial material layer.

[0071] Step S300: Fill the deep trenches to form a deep trench isolation structure 130. The deep trench isolation structure 130 encloses a pixel region 121, and the epitaxial material layer forms an epitaxial layer 120.

[0072] Step S400: Form a first doped region 1211, a second doped region 1212, and a third doped region 1213 within the pixel region 121. In the direction close to the substrate 110 on the side of the epitaxial layer 120 away from the substrate 110, the first doped region 1211, the second doped region 1212, and the third doped region 1213 are arranged in sequence. The second doped region 1212 is located between the first doped region 1211 and the third doped region 1213, and the first doped region 1211 and the third doped region 1213 have a first doping type, while the second doped region 1211 has a second doping type.

[0073] Regarding the manufacturing method of the single-photon avalanche diode device 100 obtained in the manufacturing method of the single-photon avalanche diode device 100, reference can be made to the above description of the single-photon avalanche diode device 100, and details will not be elaborated here.

[0074] In this embodiment, by first preparing the deep trench isolation structure 130 and then preparing the first doped region 1211, the second doped region 1212, and the third doped region 1213, damage to the first doped region 1211, the second doped region 1212, and the third doped region 1213 is avoided.

[0075] It should be understood that although Figure 7 the steps in the flowchart of Figure 7 are shown in sequence according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless there is a clear description in this article, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover,

[0076] at least a part of the steps in

[0077] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features of the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this application.

[0078] The above-described embodiments only represent several implementation manners of this application. The description is relatively specific and detailed, but it should not be understood as a limitation to the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of this application, several modifications and improvements can still be made, and these all belong to the protection scope of this application. Therefore, the protection scope of the patent of this application should be subject to the appended claims. The above is only the preferred implementation manner of this application, and does not limit the patent scope of this application. Any equivalent structural transformation made by using the content of the specification and drawings of this application under the inventive concept of this application, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of this application.

Claims

1. A single-photon avalanche diode device, characterized in that, Including: Substrate; An epitaxial layer located on one side of the substrate. The epitaxial layer has a plurality of pixel regions. In the direction from the side of the epitaxial layer away from the substrate towards the substrate, at least one of the pixel regions includes a first doped region, a second doped region, and a third doped region arranged continuously. The second doped region is located between the first doped region and the third doped region, and the first doped region and the third doped region have a first doping type, while the second doped region has a second doping type.

2. The single-photon avalanche diode device according to claim 1, wherein The orthographic projection of the first doped region on the substrate overlaps with the orthographic projection of the third doped region on the substrate, and / or, in the thickness direction of the epitaxial layer, the size of the first doped region is the same as the size of the third doped region.

3. The single-photon avalanche diode device according to claim 1, characterized in that, The doping concentration of the first doped region is the same as the doping concentration of the third doped region, and / or, the doping ions of the first doped region are the same as the doping ions of the third doped region.

4. The single-photon avalanche diode device according to claim 1, characterized in that, In the direction parallel to the substrate, the size of the second doped region is greater than the size of the first doped region, and / or, in the direction parallel to the substrate, the size of the second doped region is greater than the size of the third doped region.

5. The single-photon avalanche diode device according to claim 1, wherein The single-photon avalanche diode device further includes: A deep trench isolation structure extending from the surface of the epitaxial layer away from the substrate into the epitaxial layer. The deep trench isolation structure surrounds the pixel region.

6. The single-photon avalanche diode device according to claim 5, characterized in that The deep trench isolation structure protrudes from the surface of the epitaxial layer away from the substrate.

7. The single-photon avalanche diode device according to claim 5, characterized in that, The deep trench isolation structure is electrically connected to the first doped region.

8. The single-photon avalanche diode device according to claim 7, wherein The single-photon avalanche diode device further includes: A first well region surrounding the first doped region and isolated from the first doped region. The first well region has a first doping type, and the deep trench isolation structure, the first doped region, and the first well region are electrically connected; And / or, the single-photon avalanche diode device further includes: A second well region surrounding the first doped region and isolated from the first doped region. The second well region has a second doping type, and in the direction from the side of the epitaxial layer away from the substrate towards the substrate, the second well region extends into the epitaxial layer via the second doped region. The second well region is located between the first doped region and the first well region.

9. The single-photon avalanche diode device according to claim 5, characterized in that The deep trench isolation structure has a first distance from the substrate, and the third doped region has a second distance from the substrate. The first distance is less than the second distance.

10. A method for preparing a single-photon avalanche diode device, characterized in that, The manufacturing method of the single-photon avalanche diode device includes the following steps: Providing a substrate; Forming an epitaxial material layer on one side of the substrate. The epitaxial material layer has deep trenches extending from the side of the epitaxial material layer away from the substrate into the epitaxial material layer; Filling the deep trenches to form a deep trench isolation structure. The deep trench isolation structure encloses to form pixel regions, and the epitaxial material layer forms an epitaxial layer; A first doped region, a second doped region, and a third doped region are formed in the pixel region. In a direction approaching the substrate from a side of the epitaxial layer far from the substrate, the first doped region, the second doped region, and the third doped region are arranged in sequence, and the first doped region and the third doped region have a first doping type, and the second doped region has a second doping type.

Images