CN117116957A - Single photon avalanche diode array and preparation method thereof - Google Patents
Single photon avalanche diode array and preparation method thereof Download PDFInfo
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- CN117116957A CN117116957A CN202311214698.2A CN202311214698A CN117116957A CN 117116957 A CN117116957 A CN 117116957A CN 202311214698 A CN202311214698 A CN 202311214698A CN 117116957 A CN117116957 A CN 117116957A
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- 238000002360 preparation method Methods 0.000 title abstract description 8
- 229910052751 metal Inorganic materials 0.000 claims abstract description 92
- 239000002184 metal Substances 0.000 claims abstract description 92
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 claims abstract description 49
- 229910052721 tungsten Inorganic materials 0.000 claims abstract description 49
- 239000010937 tungsten Substances 0.000 claims abstract description 49
- 239000000758 substrate Substances 0.000 claims abstract description 44
- 238000002955 isolation Methods 0.000 claims abstract description 41
- 229910052782 aluminium Inorganic materials 0.000 claims abstract description 13
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims abstract description 13
- 239000000463 material Substances 0.000 claims abstract description 13
- 238000000151 deposition Methods 0.000 claims description 23
- 238000004519 manufacturing process Methods 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 15
- 230000004888 barrier function Effects 0.000 claims description 11
- 230000008569 process Effects 0.000 claims description 8
- 239000004065 semiconductor Substances 0.000 abstract description 2
- NRTOMJZYCJJWKI-UHFFFAOYSA-N Titanium nitride Chemical compound [Ti]#N NRTOMJZYCJJWKI-UHFFFAOYSA-N 0.000 description 5
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- 229910052719 titanium Inorganic materials 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 238000000149 argon plasma sintering Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000001514 detection method Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000001259 photo etching Methods 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
Classifications
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
- Y02P70/50—Manufacturing or production processes characterised by the final manufactured product
Abstract
The application relates to the field of semiconductors and discloses a single photon avalanche diode array and a preparation method thereof, wherein the single photon avalanche diode array comprises a plurality of single photon avalanche diode units, and the front surface of each single photon avalanche diode unit comprises a PN junction; the periphery of each single photon avalanche diode unit is provided with a deep trench isolation structure; the back surface of each single photon avalanche diode unit is provided with a metal grid above each deep trench isolation structure; the metal grid is electrically connected with the deep trench isolation structure through a first contact hole; the metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole; the metal grid is made of tungsten material. The metal grid is a tungsten metal grid, and the reflection of tungsten to light is smaller than that of aluminum, so that the tungsten metal grid in the single photon avalanche diode array has small reflection of tungsten to light, crosstalk can be reduced, and meanwhile, the flash phenomenon is weakened.
Description
Technical Field
The application relates to the field of semiconductors, in particular to a single photon avalanche diode array and a preparation method thereof.
Background
A single photon avalanche photodiode (single photon avalanche diode, SPAD) is a solid state photodetector that operates in geiger mode (reverse bias voltage greater than its avalanche breakdown voltage) to enable single photon detection using the avalanche effect. Single photon avalanche photodiodes typically have high photon detection efficiency, wide spectral response range, extremely high sensitivity, and low power consumption.
In fabricating a device including a single photon avalanche photodiode, a back side metal grid (Backside Metal Grid, BMG) is fabricated on the back side of the single photon avalanche photodiode to form the anode of the single photon avalanche photodiode. At present, the back metal grid is made of metal aluminum, the aluminum reflects light greatly, and the single photon avalanche photodiode has the defects of large Crosstalk (cross talk) and obvious flash (flash) phenomenon.
Therefore, how to solve the above technical problems should be of great interest to those skilled in the art.
Disclosure of Invention
The application aims to provide a single photon avalanche diode array and a preparation method thereof, which are used for reducing crosstalk of the single photon avalanche diode and weakening a flash phenomenon.
In order to solve the technical problems, the application provides a single photon avalanche diode array, which comprises a plurality of single photon avalanche diode units, wherein the front surface of each single photon avalanche diode unit comprises a PN junction;
the periphery of each single photon avalanche diode unit is provided with a deep trench isolation structure;
the back surface of each single photon avalanche diode unit is provided with a metal grid above each deep trench isolation structure;
the metal grid is electrically connected with the deep trench isolation structure through a first contact hole;
the metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole;
the metal grid is made of tungsten material.
Optionally, tungsten material is filled in the first contact hole and the second contact hole.
Optionally, the portion of the single photon avalanche diode array that does not include the PN junction includes a metal pad, and the material of the metal pad is aluminum.
Optionally, the deep trench isolation structure is filled with tungsten material.
Optionally, the back surface of each single photon avalanche diode unit is upward, and a shallow trench isolation structure is arranged below the surrounding deep trench isolation structure.
The application also provides a preparation method of the single photon avalanche diode array, which comprises the following steps:
n-type doping and P-type doping are sequentially carried out on the front surface of the epitaxial substrate, and a PN junction is formed; a single photon avalanche diode unit includes a PN junction;
manufacturing a deep trench isolation structure in the epitaxial substrate, wherein the deep trench isolation structure is positioned between adjacent single photon avalanche diode units;
manufacturing contact holes in the first dielectric layer between adjacent single photon avalanche diode units; the contact holes comprise a first contact hole and a second contact hole;
manufacturing a grid groove in a target area of the first dielectric layer, wherein the grid groove is communicated with the contact hole; the target region comprises a region between the contact holes of two adjacent single photon avalanche diode units;
depositing metal tungsten in the grid grooves to form tungsten metal grids; the tungsten metal grid is electrically connected with the deep trench isolation structure through the first contact hole; the tungsten metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole;
depositing a metal layer on one side of the back surface of the epitaxial substrate, and removing the metal layer positioned in the light incident region to form a metal bonding pad;
and carrying out subsequent process treatment on one side of the back surface of the epitaxial substrate to obtain the single photon avalanche diode array.
Optionally, before depositing the metal tungsten in the grid groove, the method further comprises:
a first adhesion barrier layer is deposited in the contact hole and the grid recess.
Optionally, before depositing the metal layer on the back side of the epitaxial substrate, the method further includes:
depositing a second adhesion barrier layer on the back side of the epitaxial substrate;
correspondingly, depositing a metal layer on the back side of the epitaxial substrate comprises:
and depositing a metal layer on the surface of the second adhesion barrier layer.
Optionally, the target region is a region where the first dielectric layer is located between the contact holes of two adjacent single photon avalanche diode units.
Optionally, the target area is larger than an area of the first dielectric layer between the contact holes of two adjacent single photon avalanche diode units.
Optionally, performing subsequent processing on the back side of the epitaxial substrate to obtain a single photon avalanche diode array includes:
sequentially depositing a second dielectric layer and a third dielectric layer on one side of the back surface of the epitaxial substrate;
growing a flat layer on the surface of the third dielectric layer;
and manufacturing a micro lens on the surface of the flat layer to obtain the back-illuminated SPAD array.
The application provides a single photon avalanche diode array, which comprises a plurality of single photon avalanche diode units, wherein the front surface of each single photon avalanche diode unit comprises a PN junction; the periphery of each single photon avalanche diode unit is provided with a deep trench isolation structure; the back surface of each single photon avalanche diode unit is provided with a metal grid above each deep trench isolation structure; the metal grid is electrically connected with the deep trench isolation structure through a first contact hole; the metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole; the metal grid is made of tungsten material.
Therefore, the single photon avalanche diode array comprises a plurality of single photon avalanche diode units, and the metal grid above the deep groove isolation structure is a tungsten metal grid, and the tungsten metal grid has small reflection to light because the tungsten is smaller than aluminum, so that the crosstalk can be reduced, and the flash phenomenon can be reduced. And a deep groove isolation structure is arranged between the adjacent single photon avalanche diode units, so that optical crosstalk and electrical crosstalk between the adjacent single photon avalanche diode units can be restrained or reduced.
In addition, the application also provides a single photon avalanche diode array with the advantages.
Drawings
For a clearer description of embodiments of the application or of the prior art, the drawings that are used in the description of the embodiments or of the prior art will be briefly described, it being apparent that the drawings in the description below are only some embodiments of the application, and that other drawings can be obtained from them without inventive effort for a person skilled in the art.
Fig. 1 is a flowchart of a method for manufacturing a single photon avalanche diode array according to an embodiment of the present application;
fig. 2 to 13 are process flow diagrams of a preparation process of a single photon avalanche diode array according to an embodiment of the present application;
FIG. 14 is a top view of a back side of a single photon avalanche diode array in accordance with an embodiment of the present application;
in the figure: 1. epitaxial substrate, 2, PN junction, 3, first dielectric layer, 4, contact hole, 5, light scattering structure, 6, grid groove, 7, metal layer, 8, second dielectric layer, 9, third dielectric layer, 10, flat layer, 11, epitaxial wafer, 12, substrate, 13, microlens, 14, tungsten contact hole, 15, tungsten metal grid, 16, deep trench isolation structure, 17, metal pad, 18, back metal grid, 19, back electrode.
Detailed Description
In order to better understand the aspects of the present application, the present application will be described in further detail with reference to the accompanying drawings and detailed description. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.
In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application, but the present application may be practiced in other ways other than those described herein, and persons skilled in the art will readily appreciate that the present application is not limited to the specific embodiments disclosed below.
As described in the background section, the back metal grid is currently made of metal aluminum, and aluminum has larger light reflection, so that the single photon avalanche photodiode has the defects of large crosstalk and obvious flash phenomenon.
In view of this, the present application provides a method for preparing a single photon avalanche diode array, please refer to fig. 1, comprising:
step S101: n-type doping and P-type doping are sequentially carried out on the front surface of the epitaxial substrate, and a PN junction is formed; a single photon avalanche diode cell includes a PN junction.
Referring to fig. 2, the epitaxial substrate 1 includes a substrate 12 and an epitaxial wafer 11, and n-type doping and P-type doping are performed in the epitaxial wafer 11.
Step S102: deep trench isolation structures are fabricated in the epitaxial substrate, the deep trench isolation structures being located between adjacent single photon avalanche diode cells.
Referring to fig. 3, after forming the PN junction 2, conventional process flows, such as fabricating the deep trench isolation structure 16, the light scattering structure 5, etc., are continued, and are well known to those skilled in the art, and will not be described in detail herein. Then, the first dielectric layer 3 is deposited, and the first dielectric layer 3 is subjected to chemical mechanical polishing treatment. The first dielectric layer 3 may be a silicon oxide layer.
Step S103: and manufacturing contact holes in the first dielectric layer between adjacent single photon avalanche diode units.
The contact holes include a first contact hole and a second contact hole.
Referring to fig. 4, the first dielectric layer 3 is etched by a photolithography process to form a contact hole 4.
Step S104: manufacturing a grid groove in a target area of the first dielectric layer, wherein the grid groove is communicated with the contact hole; the target region includes a region between the contact holes of two adjacent single photon avalanche diode cells.
The grid grooves can be made by adopting a photoetching mode.
The size of the target area is not limited and can be set by itself.
Referring to fig. 5, as an embodiment, the target area is an area where the first dielectric layer 3 is located between the contact holes 4 of two adjacent single photon avalanche diode units. The grid groove 6 is communicated with the contact hole 4 and is in an inverted U shape.
Referring to fig. 6 and 7, as another embodiment, the target area is larger than the area of the first dielectric layer 3 between the contact holes 4 of two adjacent single photon avalanche diode cells.
The target region may be a region between the contact holes 4 of two adjacent single photon avalanche diode units, and a portion of the target region may be shifted to the outside of either one of the contact holes 4, for example, a rightward shift portion in fig. 6, or may be shifted to the left, of course; alternatively, the target region is the region between the contact holes 4 of two adjacent single photon avalanche diode cells, plus a portion offset outside both contact holes 4, as shown in fig. 7.
Step S105: depositing metal tungsten in the grid grooves to form tungsten metal grids; the tungsten metal grid is electrically connected with the deep trench isolation structure through the first contact hole; the tungsten metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through the second contact hole.
It should be noted that it is also necessary to deposit metal in the contact holes, and the metal deposited in the contact holes may be tungsten.
Taking the structure shown in fig. 5 as an example, this step is illustrated, as shown in fig. 8, metal tungsten is deposited on the back surface, and chemical mechanical polishing is performed, so that only the contact hole 4 and the grid groove 6 are filled with tungsten, and a tungsten contact hole 14 and a tungsten metal grid 15 are obtained.
Step S106: and depositing a metal layer on one side of the back surface of the epitaxial substrate, and removing the metal layer positioned in the light incident region to form a metal bonding pad.
The metal layer 7 is deposited on the whole back surface as shown in fig. 9, then the metal layer 7 in the light incident region is removed as shown in fig. 10, the metal layer 7 in the electrode region is reserved, and the metal layer 7 in the electrode region is used as a metal pad 17 as shown in fig. 11.
The material of the metal layer 7 may be aluminum.
Step S107: and carrying out subsequent process treatment on one side of the back surface of the epitaxial substrate to obtain the single photon avalanche diode array.
As an implementation manner, performing subsequent process treatment on the back side of the epitaxial substrate to obtain a single photon avalanche diode array includes:
sequentially depositing a second dielectric layer and a third dielectric layer on one side of the back surface of the epitaxial substrate;
growing a flat layer on the surface of the third dielectric layer;
and manufacturing a micro lens on the surface of the flat layer to obtain the back-illuminated SPAD array.
Referring to fig. 12 to 13, the second dielectric layer 8 is deposited on the surfaces of the first dielectric layer 3 and the tungsten metal grid 15, the third dielectric layer 9 is deposited on the surface of the second dielectric layer 8, the planarization layer 10 is deposited on the surface of the third dielectric layer 9, and the micro-lenses 13 are positioned on the surface of the planarization layer 10.
The second dielectric layer 8 may be a silicon oxide layer, the third dielectric layer 9 may be a silicon nitride layer, and the planarization layer 10 may be an organic transparent layer.
In this embodiment, when preparing the single photon avalanche diode array, after the contact hole 4 is made in the first dielectric layer 3, the grid groove 6 is communicated with the contact hole 4, and then the tungsten contact hole 14 and the tungsten metal grid 15 are formed by filling tungsten in the grid groove 6 and the contact hole 4. Since tungsten reflects light less than aluminum, the tungsten metal grid 15 in the single photon avalanche diode array of the present application reflects light less, and can reduce crosstalk and reduce the flash phenomenon.
On the basis of the above embodiment, in one embodiment of the present application, before depositing the metal tungsten in the grid groove, the method further includes:
a first adhesion barrier is deposited in the contact holes 4 and the grid grooves 6.
The first adhesion barrier layer may be a stack of a titanium layer and a titanium nitride layer, the titanium layer being deposited first, followed by the titanium nitride layer.
On the basis of any one of the foregoing embodiments, in one embodiment of the present application, before depositing the metal layer on the back surface side of the epitaxial substrate, the method further includes:
depositing a second adhesion barrier layer on the back side of the epitaxial substrate 1;
correspondingly, depositing the metal layer 7 on the back side of the epitaxial substrate 1 comprises:
a metal layer 7 is deposited on the surface of the second adhesion barrier.
The second adhesion barrier layer may be a stack of a titanium layer and a titanium nitride layer, the titanium layer being deposited first, followed by the titanium nitride layer. A metal layer 7 is deposited on the surface of the titanium nitride layer.
The application also provides a single photon avalanche diode array, as shown in fig. 13, which comprises a plurality of single photon avalanche diode units, wherein the front surface of each single photon avalanche diode unit comprises a PN junction 2;
surrounding each of the single photon avalanche diode cells is a deep trench isolation structure 16;
the back side of each single photon avalanche diode cell is provided with a metal grid just above each deep trench isolation structure 16;
the metal grid is electrically connected with the deep trench isolation structure 16 through a first contact hole;
the metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole;
the metal grid is made of tungsten material.
The PN junction 2 is formed by N-type doping and P-type doping of an epitaxial wafer of the epitaxial substrate.
When the single photon avalanche diode unit is a back-illuminated single photon avalanche diode unit, the front surface of the single photon avalanche diode unit corresponds to the front surface of the epitaxial substrate, and the back surface of the single photon avalanche diode unit corresponds to the back surface of the epitaxial substrate.
The back of the epitaxial substrate is deposited with a first dielectric layer, contact holes are formed in the first dielectric layer and between adjacent single photon avalanche diode units, and the contact Kong Fen is a first contact hole and a second contact hole.
The deep trench isolation structures 16 can suppress or reduce optical and electrical crosstalk between adjacent single photon avalanche diode cells.
As an embodiment, the deep trench isolation structure 16 is filled with tungsten material, which is a metal material, so as to further reduce optical crosstalk between adjacent single photon avalanche diode units.
The area of the metal grid may be the area between the contact holes of two adjacent single photon avalanche diode units, or may be larger than the area of the first dielectric layer between the contact holes of two adjacent single photon avalanche diode units.
As an embodiment, the first contact hole and the second contact hole are filled with tungsten material.
In one embodiment of the present application, the portion of the single photon avalanche diode array that does not include the PN junction includes a metal pad, and the metal pad is made of aluminum. Aluminum is excellent in electrical conductivity.
The portion that does not include the PN junction, i.e., the non-light entry region on the single photon avalanche diode array.
In the single photon avalanche diode array in this embodiment, a contact hole and a metal grid are disposed in the first dielectric layer, the metal grid is in communication with the contact hole, and the metal grid is made of tungsten. Because tungsten reflects light less than aluminum, the tungsten metal grid in the single photon avalanche diode array in the embodiment reflects light less, can reduce crosstalk, and simultaneously reduces the flash phenomenon.
Based on the above embodiments, in one embodiment of the present application, the back surface of each single photon avalanche diode unit is upward, and the trench isolation structure 16 is a shallow trench isolation structure below the periphery of the deep trench isolation structure.
In this embodiment, the epitaxial substrate of adjacent single photon avalanche diode cells can be separated by providing deep trench isolation structures 16 and shallow trench isolation structures between adjacent single photon avalanche diode cells.
In this specification, each embodiment is described in a progressive manner, and each embodiment is mainly described in a different point from other embodiments, so that the same or similar parts between the embodiments are referred to each other.
The single photon avalanche diode array and the preparation method thereof provided by the application are described in detail. The principles and embodiments of the present application have been described herein with reference to specific examples, the description of which is intended only to facilitate an understanding of the method of the present application and its core ideas. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the application can be made without departing from the principles of the application and these modifications and adaptations are intended to be within the scope of the application as defined in the following claims.
Claims (11)
1. A single photon avalanche diode array comprising a plurality of single photon avalanche diode cells, each single photon avalanche diode cell having a front side comprising a PN junction;
the periphery of each single photon avalanche diode unit is provided with a deep trench isolation structure;
the back surface of each single photon avalanche diode unit is provided with a metal grid above each deep trench isolation structure;
the metal grid is electrically connected with the deep trench isolation structure through a first contact hole;
the metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole;
the metal grid is made of tungsten material.
2. The array of claim 1, wherein the first contact hole and the second contact hole are filled with tungsten material.
3. The array of claim 1, wherein the portion of the single photon avalanche diode array that does not include a PN junction further comprises: and the metal bonding pad is made of aluminum.
4. The array of claim 1, wherein the deep trench isolation structures are filled internally with tungsten material.
5. The array of any one of claims 1 to 4, wherein each single photon avalanche diode cell has a back side facing upward and a shallow trench isolation structure below the surrounding deep trench isolation structure.
6. A method of making a single photon avalanche diode array comprising:
n-type doping and P-type doping are sequentially carried out on the front surface of the epitaxial substrate, and a PN junction is formed; a single photon avalanche diode unit includes a PN junction;
manufacturing a deep trench isolation structure in the epitaxial substrate, wherein the deep trench isolation structure is positioned between adjacent single photon avalanche diode units;
manufacturing contact holes in the first dielectric layer between adjacent single photon avalanche diode units; the contact holes comprise a first contact hole and a second contact hole;
manufacturing a grid groove in a target area of the first dielectric layer, wherein the grid groove is communicated with the contact hole; the target region comprises a region between the contact holes of two adjacent single photon avalanche diode units;
depositing metal tungsten in the grid grooves to form tungsten metal grids; the tungsten metal grid is electrically connected with the deep trench isolation structure through the first contact hole; the tungsten metal grid is electrically connected with the epitaxial substrate of the single photon avalanche diode unit through a second contact hole;
depositing a metal layer on one side of the back surface of the epitaxial substrate, and removing the metal layer positioned in the light incident region to form a metal bonding pad;
and carrying out subsequent process treatment on one side of the back surface of the epitaxial substrate to obtain the single photon avalanche diode array.
7. The method of making a single photon avalanche diode array according to claim 6, further comprising, prior to depositing metallic tungsten in said grid recess:
a first adhesion barrier layer is deposited in the contact hole and the grid recess.
8. The method of fabricating a single photon avalanche diode array according to claim 6, further comprising, prior to depositing a metal layer on a backside of said epitaxial substrate:
depositing a second adhesion barrier layer on the back side of the epitaxial substrate;
correspondingly, depositing a metal layer on the back side of the epitaxial substrate comprises:
and depositing a metal layer on the surface of the second adhesion barrier layer.
9. The method of making a single photon avalanche diode array according to claim 6, wherein said target area is an area of said first dielectric layer between said contact holes of two adjacent single photon avalanche diode cells.
10. The method of making a single photon avalanche diode array according to claim 6, wherein said target area is larger than an area of said first dielectric layer between said contact holes of two adjacent said single photon avalanche diode cells.
11. The method of manufacturing a single photon avalanche diode array according to any one of claims 6 to 10, wherein performing a subsequent process treatment on a back side of the epitaxial substrate to obtain the single photon avalanche diode array comprises:
sequentially depositing a second dielectric layer and a third dielectric layer on one side of the back surface of the epitaxial substrate;
growing a flat layer on the surface of the third dielectric layer;
and manufacturing a micro lens on the surface of the flat layer to obtain the back-illuminated SPAD array.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311214698.2A CN117116957A (en) | 2023-09-19 | 2023-09-19 | Single photon avalanche diode array and preparation method thereof |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311214698.2A CN117116957A (en) | 2023-09-19 | 2023-09-19 | Single photon avalanche diode array and preparation method thereof |
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| CN117116957A true CN117116957A (en) | 2023-11-24 |
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| CN202311214698.2A Pending CN117116957A (en) | 2023-09-19 | 2023-09-19 | Single photon avalanche diode array and preparation method thereof |
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