Single photon avalanche diode device and tof receiving chip

Abstract

The utility model relates to the field of SPAD, and discloses a single photon avalanche diode device and a Tof receiving chip, and the single photon avalanche diode device comprises a substrate and an epitaxial wafer located above the substrate. The first P-type doped region, the first N-type doped region and the second N-type doped region extend downwards along the thickness direction of the epitaxial wafer above the epitaxial wafer, the first N-type doped region surrounds the second N-type doped region, the first P-type doped region surrounds the first N-type doped region, and the first P-type doped region and the first N-type doped region form a PN junction; the P-type isolation region is positioned above the epitaxial wafer; and the micro-lens is positioned on one side, away from the epitaxial wafer, of the substrate. According to the invention, the PN junction is longitudinal, that is, the avalanche region is vertical, and the avalanche breakdown area can be increased by increasing the extension depth of the PN junction, so that the photon detection efficiency is improved, and edge breakdown and excessive dark current can be effectively avoided.

Description

Technical Field

[0001] The present application relates to the field of SPAD, and in particular to a single photon avalanche diode device and a TOF receiving chip. Background Art

[0002] Single Photon Avalanche Diode (SPAD) is a photoelectric detection avalanche diode with single photon detection capability. The P-doped region 1' and the N-doped region 2' forming the PN junction are stacked up and down in the vertical direction (along the thickness of the epitaxial wafer), such as Figure 1 shown.

[0003] The size of the overlapping area of ​​the P-doped region 1' and the N-doped region 2' determines the size of the photon detection efficiency (PhotoDetection Efficiency, referred to as PDE). In order to obtain sufficient photon detection efficiency, it is necessary to make the length d1 of the P-doped region 1' larger, and the corresponding length of the N-doped region 2' should also be larger. However, for a small-sized single-photon avalanche diode, its side length is limited. The larger the length d1 of the P-doped region 1', the smaller the distance L1 between the N-doped region 2' and the P-type isolation region 3 at the edge. The smaller the distance between the N-doped region 2' and the P-type isolation region 3 at the edge, the larger the electric field, which makes it easy for edge breakdown or excessive dark current to occur.

[0004] Therefore, how to solve the above technical problems should be the focus of technical personnel in this field. Utility Model Content

[0005] The purpose of this application is to provide a single-photon avalanche diode device and a TOF receiving chip to improve the response speed of the single-photon avalanche diode device, while effectively avoiding device edge breakdown and excessive dark current.

[0006] In order to solve the above technical problems, the present application provides a single photon avalanche diode device, comprising:

[0007] A substrate and an epitaxial wafer located above the substrate;

[0008] A first P-type doping region, a first N-type doping region, and a second N-type doping region extending downward along the thickness direction of the epitaxial wafer above the epitaxial wafer, wherein the first N-type doping region surrounds the second N-type doping region, the first P-type doping region surrounds the first N-type doping region, and the first P-type doping region and the first N-type doping region form a PN junction;

[0009] a P-type isolation region located above the epitaxial wafer;

[0010] A microlens is located on a side of the substrate away from the epitaxial wafer.

[0011] Optionally, it also includes:

[0012] a second P-type doped region located in the P-type isolation region;

[0013] a third N-type doping region located in the second N-type doping region;

[0014] An electrode in contact with the second P-type doping region and the third N-type doping region.

[0015] Optionally, the doping concentration of the second P-type doping region is greater than the doping concentration of the first P-type doping region; the doping concentration of the third N-type doping region is greater than the doping concentration of the second N-type doping region; and the doping concentration of the second N-type doping region is greater than the doping concentration of the first N-type doping region.

[0016] Optionally, the longitudinal depth of the first P-type doped region accounts for 75% to 95% of the longitudinal depth of the single-photon avalanche diode device; the longitudinal depth of the first N-type doped region accounts for 75% to 95% of the longitudinal depth of the first P-type doped region.

[0017] Optionally, the lateral side length of the single-photon avalanche diode device ranges from 3 microns to 5 microns; the longitudinal depth of the single-photon avalanche diode device ranges from 5 microns to 10 microns; and the longitudinal depth of the first P-type doped region ranges from 4.5 microns to 9.5 microns.

[0018] Optionally, a contact surface between the first P-type doped region and the bottom surface of the epitaxial wafer is a curved surface.

[0019] Optionally, the P-type isolation region is located around the single-photon avalanche diode device.

[0020] Optionally, it also includes:

[0021] A deep trench isolation structure is located above the epitaxial wafer, and the deep trench isolation structure is located on the peripheral side of the P-type isolation region.

[0022] The present application also provides a single photon avalanche diode device, comprising:

[0023] A substrate and an epitaxial wafer located above the substrate;

[0024] A first P-type doping region, a first N-type doping region, and a second N-type doping region extending downward along the thickness direction of the epitaxial wafer above the epitaxial wafer, wherein the first N-type doping region surrounds the second N-type doping region, the first P-type doping region surrounds the first N-type doping region, and the first P-type doping region and the first N-type doping region form a PN junction;

[0025] a P-type isolation region located above the epitaxial wafer;

[0026] A microlens is located above the epitaxial wafer.

[0027] The present application also provides a TOF receiving chip, comprising a single-photon avalanche diode array, wherein the array comprises a plurality of any one of the single-photon avalanche diode devices described above or the single-photon avalanche diode devices described above.

[0028] A single-photon avalanche diode device provided in the present application includes: a substrate and an epitaxial wafer located above the substrate; a first P-type doped region, a first N-type doped region, and a second N-type doped region extending downward along the thickness direction of the epitaxial wafer above the epitaxial wafer, wherein the first N-type doped region surrounds the second N-type doped region, the first P-type doped region surrounds the first N-type doped region, and the first P-type doped region and the first N-type doped region form a PN junction; a P-type isolation region located above the epitaxial wafer; and a microlens located on a side of the substrate away from the epitaxial wafer.

[0029] It can be seen that in the single-photon avalanche diode device of the present application, the first P-type doping region and the first N-type doping region form a PN junction, and the first P-type doping region and the first N-type doping region extend downward along the thickness direction of the epitaxial wafer in the epitaxial wafer, that is, the PN junction of the present application is along the longitudinal direction, that is, a vertical avalanche region is formed in the present application. When the device size is relatively small, the avalanche breakdown area can be increased by increasing the extension depth of the first P-type doping region and the first N-type doping region, thereby increasing the photon detection efficiency. Moreover, under the vertical avalanche region structure, the photogenerated electrons generated in the deep region can reach the avalanche region in a short time, thereby improving the response speed of the single-photon avalanche diode device. In addition, since the avalanche region is vertically distributed, while increasing the avalanche breakdown area, it will not cause the distance between the first N-type doping region and the P-type isolation region to decrease. Compared with the related art, the present application can increase the distance between the first N-type doping region and the P-type isolation region, effectively avoiding edge breakdown and the occurrence of excessive dark current.

[0030] In addition, the present application also provides a tof receiving chip having the above advantages. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions of the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0032] Figure 1 A schematic cross-sectional view of a single photon avalanche diode device in the related art;

[0033] Figure 2 A schematic cross-sectional view of a single photon avalanche diode device provided in an embodiment of the present application Figure 1 ;

[0034] Figure 3 A schematic cross-sectional view of a single photon avalanche diode device provided in an embodiment of the present application Figure 2 ;

[0035] Figure 4 A schematic cross-sectional view of a single photon avalanche diode device provided in an embodiment of the present application Figure 3 ;

[0036] Figure 5 A schematic cross-sectional view of a single photon avalanche diode device provided in an embodiment of the present application Figure 4 ;

[0037] Figures 6 to 14 A process flow chart of manufacturing a single photon avalanche diode device provided in an embodiment of the present application;

[0038] In the figure, 1', P-doped region, 2', N-doped region, 1, first P-type doped region, 2, first N-type doped region, 3, P-type isolation region, 4, second N-type doped region, 5, substrate, 6, epitaxial wafer, 7, microlens, 8, second P-type doped region, 9, anode, 10, cathode, 11, third N-type doped region, 12, deep trench isolation structure, 13, groove. DETAILED DESCRIPTION

[0039] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present application.

[0040] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0041] As described in the background technology section, in order to obtain sufficient photon detection efficiency, the length d1 of the P-doped region needs to be made larger, and the corresponding length of the N-doped region should also be larger. For a small-sized single-photon avalanche diode, its side length is limited. When the length d1 of the P-doped region is made larger, the distance between the N-doped region and the P-type isolation region at the edge is smaller, and the electric field is larger, which makes it easy to cause edge breakdown or excessive dark current.

[0042] In view of this, the present application provides a single photon avalanche diode device, please refer to Figure 2 ,include:

[0043] A substrate 5 and an epitaxial wafer 6 located above the substrate 5;

[0044] A first P-type doping region 1, a first N-type doping region 2, and a second N-type doping region 4 extending downward along the thickness direction of the epitaxial wafer 6 above the epitaxial wafer 6, wherein the first N-type doping region 2 surrounds the second N-type doping region 4, the first P-type doping region 1 surrounds the first N-type doping region 2, and the first P-type doping region 1 and the first N-type doping region 2 form a PN junction;

[0045] A P-type isolation region 3 located above the epitaxial wafer 6;

[0046] A microlens 7 is located on a side of the substrate 5 facing away from the epitaxial wafer 6 .

[0047] The epitaxial wafer 6 is located on the upper surface of the substrate 5. The materials of the substrate 5 and the epitaxial wafer 6 can refer to the relevant technology and are not limited in this embodiment. For example, the substrate 5 can be a silicon substrate 5 or the like.

[0048] The P-type isolation region 3 is located above the epitaxial wafer 6 , and the upper surface of the P-type isolation region 3 is parallel to the upper surface of the epitaxial wafer 6 .

[0049] The function of the P-type isolation region 3 is to connect to the anode electrode. In this embodiment, the position of the P-type isolation region 3 is not limited and can be set at will.

[0050] As an implementation method, the P-type isolation region 3 is located on two opposite sides of the single photon avalanche diode device.

[0051] As another possible implementation mode, the P-type isolation region 3 may be located around the single-photon avalanche diode device, that is, the P-type isolation region 3 is distributed around the single-photon avalanche diode device.

[0052] The first P-type doping region 1 and the P-type isolation region 3 are formed by P-type doping, and the doping elements include but are not limited to boron.

[0053] The specific doping concentrations of the first P-type doping region 1 and the P-type isolation region 3 are not limited in this embodiment and are determined according to circumstances. The doping concentration of the first P-type doping region 1 may be less than the doping concentration of the P-type isolation region 3 .

[0054] The first N-type doping region 2 and the second N-type doping region 4 are formed by N-type doping, and the doping elements include but are not limited to phosphorus.

[0055] The specific doping concentrations of the first N-type doping region 2 and the second N-type doping region 4 are not limited in this embodiment and are determined according to circumstances. The doping concentration of the second N-type doping region 4 may be greater than the doping concentration of the first N-type doping region 2 .

[0056] The second N-type doping region 4 is connected to the cathode electrode.

[0057] Compared with the related art, in this embodiment, the first P-type doping region 1 and the first N-type doping region 2 extend downward along the thickness direction of the epitaxial wafer 6, and the first P-type doping region 1 and the first N-type doping region 2 form a PN junction, that is, in this embodiment, the PN junction is vertically distributed, and the avalanche region is vertically distributed. When it is necessary to increase the overlapping area between the first P-type doping region 1 and the first N-type doping region 2, it can be achieved by extending the longitudinal depth of the first P-type doping region 1 and the first N-type doping region 2, thereby improving the photon detection efficiency. At the same time, when increasing the overlapping area between the first P-type doping region 1 and the first N-type doping region 2, the distance between the first N-type doping region 2 and the P-type isolation region 3 will not be affected, and through the longitudinal distribution, the distance between the first N-type doping region 2 and the P-type isolation region 3 can also be made larger, effectively avoiding edge breakdown and reducing the generation of dark current.

[0058] By setting up an avalanche region with a vertical structure, photogenerated electrons generated in a deep region can reach the avalanche region in a short time, thereby improving the response speed of the SPAD device.

[0059] It should be pointed out that in this embodiment, there is no limitation on the longitudinal depth of the first P-type doping region 1 and the first N-type doping region 2 in the vertical direction, which depends on the circumstances.

[0060] As an implementable embodiment, the longitudinal depth of the first P-type doping region 1 accounts for 75% to 95% of the longitudinal depth of the single-photon avalanche diode device; the longitudinal depth of the first N-type doping region 2 accounts for 75% to 95% of the longitudinal depth of the first P-type doping region 1, so as to make full use of the depth direction to obtain a larger avalanche area.

[0061] It should be noted that the size of the single-photon avalanche diode device is not limited in this embodiment. As an implementable embodiment, the single-photon avalanche diode device can be a small-sized device, and the lateral side length of the single-photon avalanche diode device can range from 3 microns to 5 microns; the vertical depth of the single-photon avalanche diode device can range from 5 microns to 10 microns. Correspondingly, in this small-sized device, the vertical depth of the first P-type doping region 1 can range from 4.5 microns to 9.5 microns.

[0062] The microlens 7 is located on the side of the substrate 5 away from the epitaxial wafer 6. In this embodiment, the single-photon avalanche diode device is a back-illuminated single-photon avalanche diode device.

[0063] In the single-photon avalanche diode device of this embodiment, the first P-type doping region 1 and the first N-type doping region 2 form a PN junction, and the first P-type doping region 1 and the first N-type doping region 2 extend downward in the epitaxial wafer 6 along the thickness direction of the epitaxial wafer 6, that is, the PN junction of the present application is along the longitudinal direction, that is, a vertical avalanche region is formed in the present application. When the device size is relatively small, the avalanche breakdown area can be increased by increasing the extension depth of the first P-type doping region 1 and the first N-type doping region 2, thereby increasing the photon detection efficiency. Moreover, under the vertical avalanche region structure, the photogenerated electrons generated in the deep region can reach the avalanche region in a short time, thereby improving the response speed of the single-photon avalanche diode device. In addition, since the avalanche region is vertically distributed, while increasing the avalanche breakdown area, it will not cause the distance between the first N-type doping region 2 and the P-type isolation region 3 to decrease. Compared with the related art, the present application can increase the distance between the first N-type doping region 2 and the P-type isolation region 3, effectively avoiding edge breakdown and the occurrence of excessive dark current.

[0064] Please refer to Figure 3 Based on the above embodiments, in one embodiment of the present application, the single photon avalanche diode device may further include:

[0065] a second P-type doping region 8 located in the P-type isolation region 3;

[0066] a third N-type doping region 11 located in the second N-type doping region 4;

[0067] An electrode in contact with the second P-type doping region 8 and the third N-type doping region 11 .

[0068] The electrode in contact with the second P-type doping region 8 is an anode 9 , and the electrode in contact with the third N-type doping region 11 is a cathode 10 .

[0069] It should be pointed out that in this embodiment, the relationship between the doping concentrations of the first P-type doping region 1 and the second P-type doping region 8, and the relationship between the doping concentrations of the third N-type doping region 11, the second N-type doping region 4, and the first N-type doping region 2 are not limited.

[0070] As an implementation method, the doping concentration of the second P-type doping region 8 is greater than the doping concentration of the first P-type doping region 1; the doping concentration of the third N-type doping region 11 is greater than the doping concentration of the second N-type doping region 4; and the doping concentration of the second N-type doping region 4 is greater than the doping concentration of the first N-type doping region 2.

[0071] The doping concentration of the second P-type doping region 8 is relatively high, so that an ohmic contact is formed between the anode 9 and the second P-type doping region 8 . The doping concentration of the third N-type doping region 11 is relatively high, so that an ohmic contact is formed between the cathode 10 and the third N-type doping region 11 .

[0072] Based on any of the above embodiments, in one embodiment of the present application, Figure 2 and Figure 3 As shown, the contact surface between the first P-type doping region 1 and the bottom surface of the epitaxial wafer 6 is a curved surface, that is, the first P-type doping region 1 is U-shaped.

[0073] In this embodiment, the contact surface between the first P-type doped region 1 and the bottom surface of the epitaxial wafer 6 is curved and rounded to avoid sharp right angles on the bottom contact surface. This can reduce the electric field strength in the bottom contact corner area and avoid edge breakdown.

[0074] like Figure 4 As shown, based on any of the above embodiments, in one embodiment of the present application, the single photon avalanche diode device may further include:

[0075] A deep trench isolation structure 12 is located above the epitaxial wafer 6 , and the deep trench isolation structure 12 is located around the P-type isolation region 3 .

[0076] A deep trench isolation (DTI) structure is located in the epitaxial wafer 6 . The deep trench isolation structure 12 is filled with an isolation medium, which can play an isolation role and avoid optical crosstalk between adjacent single photon avalanche diode devices.

[0077] The deep trench isolation structure 12 is located on the peripheral side of the single-photon avalanche diode device, that is, located around the single-photon avalanche diode device, which can isolate the optical crosstalk of other single-photon avalanche diode devices around it, and the isolation effect is better.

[0078] The present application also provides a single photon avalanche diode device, such as Figure 5 As shown, including:

[0079] A substrate 5 and an epitaxial wafer 6 located above the substrate 5;

[0080] A first P-type doping region 1, a first N-type doping region 2, and a second N-type doping region 4 extending downward along the thickness direction of the epitaxial wafer 6 above the epitaxial wafer 6, wherein the first N-type doping region 2 surrounds the second N-type doping region 4, the first P-type doping region 1 surrounds the first N-type doping region 2, and the first P-type doping region 1 and the first N-type doping region 2 form a PN junction;

[0081] A P-type isolation region 3 located above the epitaxial wafer 6;

[0082] A microlens 7 is located above the epitaxial wafer 6 .

[0083] In this embodiment, the microlens 7 is disposed above the epitaxial wafer 6, and the obtained single-photon avalanche diode device is a front-illuminated single-photon avalanche diode device.

[0084] For the settings of other structures in the front-illuminated single-photon avalanche diode device, reference may be made to the relevant contents of the above-mentioned back-illuminated photon avalanche diode device, which will not be described in detail here.

[0085] The present application also provides a tof (Time Of Flight) receiving chip, including a single-photon avalanche diode array, wherein the array includes a plurality of the single-photon avalanche diode devices (back-illuminated) described in any of the above embodiments; or the array includes a plurality of the single-photon avalanche diode devices (front-illuminated) described in the above embodiments.

[0086] The following uses a back-illuminated single-photon avalanche diode device as an example to illustrate the method for manufacturing the single-photon avalanche diode device in the present application.

[0087] Step 1: Figure 6 As shown, a base structure is prepared, the base structure includes a substrate 5 and an epitaxial wafer 6 located on the substrate 5;

[0088] Step 2: Figure 7 As shown, the epitaxial wafer 6 is etched along the thickness direction by photolithography to form a groove 13, and the depth of the groove 13 ranges from 4.5 microns to 9.5 microns;

[0089] Step 3: Figure 8 As shown, the bottom of the groove is isotropically etched to form a rounded corner at the bottom of the groove;

[0090] Step 4: Fig. 9 As shown, a first P-type doping region 1 is formed in the groove of the epitaxial wafer 6;

[0091] Step 5: Fig.10 As shown, a first N-type doping region 2 is formed in the groove of the epitaxial wafer 6, and a first P-type doping region 1 surrounds the first N-type doping region 2;

[0092] Step 6: Fig.11 As shown, a second N-type doping region 4 is formed in the groove of the epitaxial wafer 6, the first N-type doping region 2 surrounds the second N-type doping region 4, and the doping concentration of the second N-type doping region 4 is greater than that of the first N-type doping region 2; as mentioned above, the first P-type doping region 1, the first N-type doping region 2 and the second N-type doping region 4 are all formed by an epitaxial process.

[0093] Step 7: Fig.12 As shown, a P-type isolation region 3 is formed in the epitaxial wafer 6 by ion implantation; the P-type isolation region 3 is located on two opposite sides or peripheral sides of the single photon avalanche diode device; the doping concentration of the P-type isolation region 3 is greater than that of the first P-type doping region 1;

[0094] Step 8: Fig.13 As shown, doping is performed in the second N-type doping region 4 to form a third N-type doping region 11, and the doping concentration of the third N-type doping region 11 is greater than that of the second N-type doping region 4; doping is performed in the P-type isolation region 3 to form a second P-type doping region 8, and the doping concentration of the second P-type doping region 8 is greater than that of the P-type isolation region 3;

[0095] Step 9: Fig.14 As shown, a cathode 10 and an anode 9 are manufactured, the anode 9 is in ohmic contact with the second P-type doping region 8, and the cathode 10 is in ohmic contact with the third N-type doping region 11;

[0096] Step 10: Figure 3 As shown, a microlens 7 is fabricated on the side of the substrate 5 facing away from the epitaxial wafer 6 to obtain a single photon avalanche diode device.

[0097] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0098] The single photon avalanche diode device and the TOF receiving chip provided by the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the scheme of the present application and its core idea. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A single photon avalanche diode device, characterized in that: include: A substrate and an epitaxial wafer located above the substrate; A first P-type doping region, a first N-type doping region, and a second N-type doping region extending downward along the thickness direction of the epitaxial wafer above the epitaxial wafer, wherein the first N-type doping region surrounds the second N-type doping region, the first P-type doping region surrounds the first N-type doping region, and the first P-type doping region and the first N-type doping region form a PN junction; a P-type isolation region located above the epitaxial wafer; A microlens is located on a side of the substrate away from the epitaxial wafer.

2. The single photon avalanche diode device according to claim 1, characterized in that: Also includes: a second P-type doped region located in the P-type isolation region; a third N-type doping region located in the second N-type doping region; An electrode in contact with the second P-type doping region and the third N-type doping region.

3. The single photon avalanche diode device according to claim 2, characterized in that: The doping concentration of the second P-type doping region is greater than the doping concentration of the first P-type doping region; the doping concentration of the third N-type doping region is greater than the doping concentration of the second N-type doping region; and the doping concentration of the second N-type doping region is greater than the doping concentration of the first N-type doping region.

4. The single photon avalanche diode device according to claim 1, characterized in that: The longitudinal depth of the first P-type doping region accounts for 75% to 95% of the longitudinal depth of the single-photon avalanche diode device; the longitudinal depth of the first N-type doping region accounts for 75% to 95% of the longitudinal depth of the first P-type doping region.

5. The single photon avalanche diode device according to claim 4, characterized in that: The lateral side length of the single-photon avalanche diode device ranges from 3 microns to 5 microns; the longitudinal depth of the single-photon avalanche diode device ranges from 5 microns to 10 microns; and the longitudinal depth of the first P-type doped region ranges from 4.5 microns to 9.5 microns.

6. The single photon avalanche diode device according to claim 1, characterized in that: The contact surface between the first P-type doped region and the bottom surface of the epitaxial wafer is a curved surface.

7. The single photon avalanche diode device according to claim 1, characterized in that: The P-type isolation region is located on the peripheral side of the single-photon avalanche diode device.

8. The single photon avalanche diode device according to any one of claims 1 to 7, characterized in that: Also includes: A deep trench isolation structure is located above the epitaxial wafer, and the deep trench isolation structure is located on the peripheral side of the P-type isolation region.

9. A single photon avalanche diode device, characterized in that: include: A substrate and an epitaxial wafer located above the substrate; A first P-type doping region, a first N-type doping region, and a second N-type doping region extending downward along the thickness direction of the epitaxial wafer above the epitaxial wafer, wherein the first N-type doping region surrounds the second N-type doping region, the first P-type doping region surrounds the first N-type doping region, and the first P-type doping region and the first N-type doping region form a PN junction; a P-type isolation region located above the epitaxial wafer; A microlens is located above the epitaxial wafer.

10. A tof receiving chip, characterized in that: It comprises a single photon avalanche diode array, wherein the array comprises a plurality of single photon avalanche diode devices according to any one of claims 1 to 8 or a single photon avalanche diode device according to claim 9.

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