CN119630078A - Single photon avalanche diode, preparation method thereof and photoelectric detector - Google Patents
Single photon avalanche diode, preparation method thereof and photoelectric detector Download PDFInfo
- Publication number
- CN119630078A CN119630078A CN202311176807.6A CN202311176807A CN119630078A CN 119630078 A CN119630078 A CN 119630078A CN 202311176807 A CN202311176807 A CN 202311176807A CN 119630078 A CN119630078 A CN 119630078A
- Authority
- CN
- China
- Prior art keywords
- light
- region
- area
- semiconductor region
- transmitting layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 238000002360 preparation method Methods 0.000 title abstract description 7
- 239000004065 semiconductor Substances 0.000 claims abstract description 108
- 238000002955 isolation Methods 0.000 claims abstract description 37
- 239000000758 substrate Substances 0.000 claims description 29
- 229910052751 metal Inorganic materials 0.000 claims description 16
- 239000002184 metal Substances 0.000 claims description 16
- 239000000463 material Substances 0.000 claims description 9
- 238000005530 etching Methods 0.000 claims description 7
- 238000000151 deposition Methods 0.000 claims description 6
- 230000036961 partial effect Effects 0.000 claims description 6
- 229910052581 Si3N4 Inorganic materials 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 4
- 239000003292 glue Substances 0.000 claims description 4
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 claims description 4
- 229910052814 silicon oxide Inorganic materials 0.000 claims description 4
- 238000004519 manufacturing process Methods 0.000 claims 1
- 238000001514 detection method Methods 0.000 abstract description 17
- 230000015556 catabolic process Effects 0.000 description 12
- 239000012780 transparent material Substances 0.000 description 12
- 239000000969 carrier Substances 0.000 description 11
- 238000005286 illumination Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 4
- 238000007740 vapor deposition Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 229910021478 group 5 element Inorganic materials 0.000 description 3
- 229910052755 nonmetal Inorganic materials 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 2
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 229910052785 arsenic Inorganic materials 0.000 description 2
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- -1 for example Inorganic materials 0.000 description 2
- 229910052733 gallium Inorganic materials 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 230000031700 light absorption Effects 0.000 description 2
- 230000002093 peripheral effect Effects 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 1
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910001423 beryllium ion Inorganic materials 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 230000008094 contradictory effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052738 indium Inorganic materials 0.000 description 1
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000005468 ion implantation Methods 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000001451 molecular beam epitaxy Methods 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- 230000002829 reductive effect Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
- 230000035945 sensitivity Effects 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 125000006850 spacer group Chemical group 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
Landscapes
- Light Receiving Elements (AREA)
Abstract
本发明公开一种单光子雪崩二极管及其制备方法以及光电探测器，单光子雪崩二极管包括器件主体和反射结构，器件主体形成相对设置的入光表面和出光表面，器件主体内的中心位置还形成有光敏区，光敏区设有自出光表面向下层叠设置的第一半导体区和第二半导体区，器件主体还包括环设在中心位置外侧的边缘区，光敏区和边缘区之间还形成有隔离区；反射结构包括覆盖在出光表面上的透光层和反射层，透光层的表面形成有相连接的平面和倾斜面，倾斜面位于隔离区和第三半导体区的上方，透光层和反射层对应倾斜面的区域形成聚光区；聚光区用于将从光敏区外侧射出的光线汇聚至光敏区内。本发明技术方案旨在提升单光子雪崩二极管的光线利用率，提升探测效率。
The present invention discloses a single-photon avalanche diode and a preparation method thereof and a photodetector. The single-photon avalanche diode includes a device body and a reflective structure. The device body forms a light incident surface and a light emitting surface arranged oppositely. A photosensitive area is also formed at the center position of the device body. The photosensitive area is provided with a first semiconductor area and a second semiconductor area stacked downward from the light emitting surface. The device body also includes an edge area arranged outside the center position. An isolation area is also formed between the photosensitive area and the edge area. The reflective structure includes a light-transmitting layer and a reflective layer covering the light emitting surface. The surface of the light-transmitting layer is formed with a connected plane and an inclined surface. The inclined surface is located above the isolation area and the third semiconductor area. The light-transmitting layer and the reflective layer form a light-gathering area in the area corresponding to the inclined surface. The light-gathering area is used to gather light emitted from the outside of the photosensitive area into the photosensitive area. The technical solution of the present invention aims to improve the light utilization rate of the single-photon avalanche diode and improve the detection efficiency.
Description
Technical Field
The invention relates to the technical field of semiconductor regions, in particular to a single photon avalanche diode, a preparation method thereof and a photoelectric detector with the single photon avalanche diode.
Background
The single photon avalanche diode (SPAD, single Photon Avalanche Diode) is a semiconductor region photoelectric detector with single photon detection sensitivity, and can multiply the carrier generated by absorbed light by utilizing the characteristic that the PN junction can generate avalanche effect when working above reverse breakdown voltage, and generate a large current to be detected by an external circuit, thereby realizing the photoelectric detection process.
In the conventional photodiode structure, typically, an avalanche breakdown occurs in a middle region, and an isolation region is usually disposed between an edge region of the periphery and a main junction edge of the center, so as to reduce breakdown in the edge region. In order to improve the utilization rate of light, a reflective layer is generally disposed on the inner surface of the photodiode to reflect the light into the device, so as to increase the light quantity absorbed by the middle region, thereby increasing the capture rate of photo-generated carriers in the middle region. In the prior art, the reflective layer of the photodiode is a planar structure, and light is reflected by the reflective layer and then is reflected back to each region inside the device in parallel and uniformly, so that a large amount of light is reflected to an isolation region outside an avalanche breakdown region and an edge region at the periphery, which causes waste of a light source, and photon-generated carriers in the middle region cannot be completely captured, thereby resulting in lower photon detection efficiency (PDE, photon Detection Efficiency), and further affecting detection efficiency.
Disclosure of Invention
The invention mainly aims to provide a single photon avalanche diode and a photoelectric detector, which aim to improve the light utilization rate of the single photon avalanche diode and improve the detection efficiency.
To achieve the above object, the present invention provides a single photon avalanche diode comprising
A device main body forming a light incident surface and a light emergent surface which are oppositely arranged, wherein a photosensitive region is also formed in the device main body, the photosensitive region extends from the light emergent surface to the light incident surface, the photosensitive region is positioned at the central position of the device main body, the photosensitive region is provided with a first semiconductor region and a second semiconductor region which are downwards overlapped from the light emergent surface, the device main body also comprises an edge region which is annularly arranged at the outer side of the central position, the edge region is provided with a third semiconductor region, and an isolation region is also formed between the photosensitive region and the edge region, and
The reflecting structure comprises a light-transmitting layer and a reflecting layer, the light-transmitting layer covers the light-emitting surface, a plane and an inclined plane which are connected are formed on the surface of the light-transmitting layer, which is away from the light surface, the plane is positioned above the first semiconductor region, the inclined plane is positioned above the isolation region and the third semiconductor region, the reflecting layer covers one side of the light-transmitting layer, which is away from the light-emitting surface, the light-transmitting layer and the reflecting layer form a light-gathering region in the region corresponding to the inclined plane,
The light is emitted from the light incident surface and is emitted from the light emergent surface, the reflecting structure reflects the light back to the inner side of the device main body, and the light gathering area is used for gathering the light emitted from the outer side of the light sensing area into the light sensing area.
In one embodiment of the present invention, and an included angle formed by the inclined surface and the light emergent surface is theta which is more than or equal to 15 degrees and less than or equal to 45 degrees.
In one embodiment of the invention, the projection of the plane of the light-transmitting layer on the light-emitting surface extends outside the photosensitive region.
In an embodiment of the present invention, the material of the light-transmitting layer includes one or more of silicon oxide, silicon nitride, and transparent glue;
The reflecting layer is made of metal.
In one embodiment of the invention, the device body comprises:
A substrate, wherein the light incident surface and the light emergent surface are respectively formed on two opposite surfaces of the substrate;
the partial structure of the first semiconductor region is exposed on the light emergent surface and extends from the light emergent surface to the light incident surface, and the first semiconductor region is positioned at the center of the substrate;
The second semiconductor region is arranged on one side of the first semiconductor region, which is away from the light emitting surface, and extends from the light emitting surface to the light entering surface, a first PN junction is formed between the first semiconductor region and the second semiconductor region, and the first semiconductor region and the second semiconductor region form the photosensitive region;
The partial structure of the third semiconductor region is exposed on the light emergent surface and extends from the light emergent surface to the light incident surface, and the third semiconductor region is positioned in the edge region of the substrate;
the isolation region is arranged between the first semiconductor region and the third semiconductor region, and the light condensation region covers the surfaces of the isolation region and the third semiconductor region.
In an embodiment of the present invention, the first semiconductor region includes a first doped region and a second doped region, a surface of the first doped region is exposed at the light emitting surface and extends toward the light entering surface, the second doped region is annularly disposed around the first doped region, a part of a structure of the second doped region is exposed at the light emitting surface, the second doped region extends from the light emitting surface to the light entering surface, and the second doped region is in contact with the second semiconductor region.
In an embodiment of the invention, the third semiconductor region includes a third doped region and a fourth doped region, the third doped region is exposed at the light emitting surface from a part of the structure of the third doped region, the third doped region extends from the light emitting surface to the light incident surface, the part of the structure of the fourth doped region is exposed at the light emitting surface, the fourth doped region is disposed around the third doped region in a surrounding manner, and the fourth doped region extends from the light emitting surface to the light incident surface.
In one embodiment of the present invention, the single photon avalanche diode further includes a first electrode and a second electrode disposed on the light emitting surface, the first electrode being connected to the first semiconductor region, and the second electrode being connected to the third semiconductor region.
The invention also provides a preparation method of the single photon avalanche diode, which comprises the following steps:
Depositing an insulating light-transmitting layer on the light-emitting surface of the device main body;
etching the surface of the insulating light-transmitting layer to enable the insulating light-transmitting layer to correspond to the upper side of the first semiconductor region to form a plane, and enabling the insulating light-transmitting layer to correspond to the upper side of the third semiconductor region and the upper side of the isolation region to form an inclined plane;
And depositing a metal reflecting layer on the surface of the insulating light-transmitting layer, and forming a light-gathering area in the area of the metal reflecting layer and the insulating light-transmitting layer corresponding to the inclined surface.
The invention also discloses a photoelectric detector, which also comprises the single photon avalanche diode.
The single photon avalanche diode comprises a device main body and a reflecting structure, wherein a photosensitive area is formed in the device main body, the photosensitive area is positioned at the center of the device main body, the photosensitive area is provided with a first semiconductor area and a second semiconductor area which are downwards overlapped from a light emergent surface, an isolation area for preventing edge breakdown is arranged around the periphery of the photosensitive area, an edge area is further arranged on the outer side of the isolation area, and the edge area comprises a point semiconductor area. The reflecting structure covers the light emergent surface and comprises a light-transmitting layer and a reflecting layer which cover the light emergent surface, a plane and an inclined plane which are connected are formed on the surface of the light-transmitting layer, the inclined plane is positioned above the isolation region and the third semiconductor region, and the light-transmitting layer and the reflecting layer form a light-gathering region corresponding to the inclined plane. When the single photon avalanche diode is used, light emitted by a light source is emitted into the device main body from the light incident surface, the light can be reflected by the reflecting structure arranged on the light emergent surface of the device main body to enter the device main body again, so that the first semiconductor region and the second semiconductor region in the photosensitive region can be subjected to more illumination, the light absorption efficiency in the device main body is improved, the number of generated carriers is multiplied, and a large current is generated and detected by an external circuit, so that the photoelectric detection process is realized. The light emitted from the isolation area and the edge area can be reflected by the light-gathering area, the reflected light is converged to the photosensitive area, the light reflected to the outer side of the photosensitive area is effectively utilized, the illumination quantity in the photosensitive area is further increased, the number of carriers generated by the photosensitive area can be further multiplied, and therefore photon detection efficiency is further improved. And, light-transmitting layer and reflection stratum all are located the upper strata of device main part, do not influence the metal wiring of device main part bottom, have promoted the convenience of wiring.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to the structures shown in these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a single photon avalanche diode in accordance with the present invention;
Fig. 2 is a diagram showing the effect of the pixel reflection simulation of the single photon avalanche diode of the present invention.
Reference numerals illustrate:
100. the light emitting diode comprises a device body, 15 parts of a third semiconductor region, 10 parts of a substrate, 151 parts of a third doped region, 101 parts of a light incident surface, 153 parts of a fourth doped region, 103 parts of a light emitting surface, 20 parts of a reflecting structure, 11 parts of a first semiconductor region, 21 parts of a light transmitting layer, 111 parts of a first doped region, 211 parts of a plane, 113 parts of a second doped region, 213 parts of an inclined plane, 13 parts of a second semiconductor region, 23 parts of a reflecting layer.
The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that all directional indicators (such as up, down, left, right, front, and rear are used in the embodiments of the present invention) are merely for explaining the relative positional relationship, movement conditions, and the like between the components in a certain specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicators are changed accordingly.
In the present invention, unless explicitly specified and limited otherwise, the terms "connected," "fixed," and the like are to be construed broadly, and for example, "fixed" may be fixedly connected, detachably connected, or integrally formed, mechanically connected, electrically connected, directly connected, indirectly connected via an intervening medium, or in communication between two elements or in an interaction relationship between two elements, unless otherwise explicitly specified. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.
Furthermore, descriptions such as those referred to as "first," "second," and the like, are provided for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implying an order of magnitude of the indicated technical features in the present disclosure. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout is meant to include three side-by-side schemes, for example, "a and/or B", including a scheme, or B scheme, or a scheme that is satisfied by both a and B. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.
Single photon avalanche photodiodes operate above the breakdown voltage of the PN junction and can be used in highly sensitive photon capturing environments. In the existing single photon avalanche diode, an edge region is arranged on the periphery of a middle region, and an ISO isolation region is formed between the edge region and the middle region so as to reduce breakdown of the edge region. The surface inside the photodiode is further provided with a reflective layer 23 having a planar 211 structure for reflecting light to the inside of the photodiode to increase the amount of light absorbed by the middle region, thereby increasing the capture rate of photo-generated carriers in the middle region. However, besides the light reflected into the avalanche breakdown region is utilized, the photon-generated carriers generated by the light reflected into the isolation region and the peripheral edge region cannot be completely captured, which results in light waste, and the photon-generated carriers in the middle region cannot be completely captured, which results in lower photon detection efficiency (PDE, photon Detection Efficiency), thereby affecting the detection efficiency.
Referring to fig. 1 and 2, the invention provides a single photon avalanche diode, which comprises a device main body 100 and a reflective structure 20, wherein an incident light surface 101 and an emergent light surface 103 are formed in the device main body 100, a photosensitive region is formed in the device main body 100, the photosensitive region extends from the emergent light surface 103 to the incident light surface 101, the photosensitive region is located at the central position of the device main body 100, the photosensitive region is provided with a first semiconductor region 11 and a second semiconductor region 13 which are downwards stacked from the emergent light surface 103, the edge region is provided with a third semiconductor region 15, an isolation region is formed between the photosensitive region and the edge region, the reflective structure 20 comprises a light-transmitting layer 21 and a reflective layer, the light-transmitting layer 21 is covered on the emergent light surface 103, the surface of the light-transmitting layer 21, which is far away from the light surface, is formed with a plane 211 and an inclined plane 213 which are connected, the plane 211 is located at the central position of the device main body 100, the first semiconductor region 11 and the second semiconductor region 13 are downwards stacked from the emergent light surface 103, the light-transmitting layer is covered on the inner side of the reflective layer 21, the light-transmitting layer is reflected from the reflective layer 21, the light-transmitting layer is formed on the light-transmitting layer, the light-reflecting layer is reflected from the reflective layer, the light-transmitting layer is covered on the light-transmitting layer 21, and the reflective layer is formed on the light-transmitting region, and the light-transmitting layer is reflected from the reflective layer, and the light-transmitting layer is formed on the light-transmitting layer.
The single photon avalanche diode in the technical scheme of the invention comprises a device main body 100 and a reflecting structure 20, wherein a photosensitive region is formed in the device main body 100, the photosensitive region is positioned at the center of the device main body 100, the photosensitive region is provided with a first semiconductor region 11 and a second semiconductor region 13 which are downwards overlapped from a light emergent surface 103, an isolation region for preventing edge breakdown is arranged around the periphery of the photosensitive region, an edge region is also arranged on the outer side of the isolation region, and the edge region comprises a point semiconductor region. The reflective structure 20 covers the light emitting surface 103, the reflective structure 20 includes a light transmitting layer 21 and a reflective layer covering the light emitting surface 103, a plane 211 and an inclined plane 213 are formed on the surface of the light transmitting layer 21, the inclined plane 213 is located above the isolation region and the third semiconductor region 15, and the light transmitting layer 21 and the reflective layer form a light condensing region corresponding to the region of the inclined plane 213. When the single photon avalanche diode is used, light emitted by a light source is emitted into the device main body 100 from the light incident surface, the reflecting structure 20 arranged on the light emergent surface 103 of the device main body 100 can reflect the light to enter the device main body 100 again, so that the first semiconductor region 11 and the second semiconductor region 13 in the photosensitive region can be subjected to more illumination, the light absorption efficiency in the device main body 100 is improved, the number of generated carriers is multiplied, and a large current is generated to be detected by an external circuit, so that the photoelectric detection process is realized. The reflective structure 20 is further provided with a light condensing area, the light condensing area can reflect light emitted from the isolation area and the edge area, the reflected light is converged to the photosensitive area, the light originally reflected to the outer side of the photosensitive area is effectively utilized, the illumination quantity in the photosensitive area is further increased, the number of carriers generated by the photosensitive area can be further multiplied, and therefore photon detection efficiency is further improved. In addition, the light-transmitting layer 21 and the reflecting layer 23 of the reflecting structure 20 are both positioned on the uppermost layer of the device main body 100, so that the metal wiring at the bottom is not influenced, and the convenience of the metal wiring of the device main body 100 is improved.
It should be noted that, in the embodiment of the present invention, the structure inside the device main body 100 of the single photon avalanche diode may be an existing structure, and by optimizing the reflection structure 20 on the surface of the device main body 100, the light reflected by the reflection structure 20 is not uniformly emitted to the inside of the device, but the emitted light of the edge region and the isolation region is converged into the photosensitive region located in the center, so that the photosensitive region can obtain more illumination, the wasted light in the existing scheme is effectively utilized, the utilization rate of the light is increased, the number of generated carriers is multiplied, and the photon detection efficiency is improved.
Referring to fig. 2, fig. 2 is a graph showing simulation results of a single photon avalanche diode (SPAD pixel device) according to the present invention, and it can be seen from the graph that the reflection effect is remarkable.
It will be appreciated that the reflective structure 20 may comprise a variety of types including, for example, reflective films, light transmissive films, light concentrating regions formed by light concentrating structures.
In one embodiment, the reflective structure 20 specifically includes a light-transmitting layer 21 and a reflective layer 23, the light-transmitting layer 21 covers the surface of the light-emitting surface 103, a plane 211 and an inclined plane 213 are formed on the surface of the light-transmitting layer 21 facing away from the light surface, the inclined plane 213 is located at the outer peripheral side of the plane 211, one end of the inclined plane 213 facing away from the plane 211 is connected with the light-emitting surface 103, so that the thickness of the edge of the light-transmitting layer 21 is gradually reduced, the reflective layer 23 covers the surface of the light-transmitting layer 21, and the area of the reflective layer 23 covering the inclined plane 213 forms the light-gathering area.
In this embodiment, the transparent layer 21 is made of transparent material, and the transparent material includes one or more of silicon oxide, silicon nitride, and transparent glue, and the transparent material is usually an insulating material, so as to avoid affecting the electrode. The light-transmitting material may form a film layer with a certain thickness on the light-emitting surface 103, thereby increasing the travel of the light and providing a necessary distance for reflecting and converging the light. The thickness of each position in the light-transmitting layer 21 is not the same, and the thickness of the flat surface 211 is greater than the thickness of the inclined surface 213. In addition, the thickness of the inclined surface 213 is uniformly changed, so that the converged light is uniformly changed, the light change of the photosensitive area is relatively uniform, and the occurrence of bright and dark spots is avoided.
In this embodiment, the preparation process of the transparent layer 21 may be to deposit one or more layers of transparent materials with uniform thickness by vapor deposition, and then etch the deposited transparent materials above the edge region and the isolation region by etching, so that an inclined slope appears on the outer edge of the transparent materials. Wherein the inclined surface 213 surrounds the outer periphery of the planar surface 211. It can be appreciated that, in order to reflect light to the middle photosensitive area as much as possible, one end of the inclined surface 213 is directly connected to the light emitting surface 103, so that an included angle θ formed by the inclined surface 213 and the light emitting surface 103 is between 15 ° and 45 °, so that the reflection range of the light condensing area can be increased to avoid light waste in the edge area.
The material of the reflective layer 23 may be a metal material, and the reflective layer 23 is directly deposited on the side of the light-transmitting layer 21 away from the light-emitting surface 103 by vapor deposition. It will be appreciated that the reflective layer is opaque and is capable of reflecting light. Since the light-transmitting layer 21 is formed with the plane 211 and the inclined plane 213, the reflecting surface of the reflecting layer is also formed with the plane 211 and the inclined plane consistent with the light-transmitting layer 21, the plane 211 can reflect the light rays emitted from the photosensitive region, and the inclined plane can reflect and collect the light rays emitted from the edge region and the isolation region, so that the reflected light rays are collected to the photosensitive region, and the utilization rate of the light rays is improved. It should be noted that, the projection of the plane 211 of the light-transmitting layer 21 on the light-emitting surface 103 can extend to the outside of the photosensitive region, and the width of the photosensitive region is slightly larger, so as to ensure that the light emitted from the photosensitive region can be uniformly reflected by the plane 211 of the reflective layer 23.
Referring to fig. 1, in an embodiment of the present invention, the device body 100 includes:
a substrate 10, wherein the light incident surface 101 and the light emergent surface 103 are respectively formed on two opposite surfaces of the substrate 10;
a first semiconductor region 11, wherein a part of the first semiconductor region 11 is exposed from the light-emitting surface 103 and extends from the light-emitting surface 103 to the light-incident surface 101, and the first semiconductor region 11 is located at the center of the substrate 10;
A second semiconductor region 13, where the second semiconductor region 13 is disposed on a side of the first semiconductor region 11 facing away from the light emitting surface 103, the second semiconductor region 13 extends from the light emitting surface 103 toward the light incident surface 101, a first PN junction is formed between the first semiconductor region 11 and the second semiconductor region 13, and the first semiconductor region 11 and the second semiconductor region 13 form the photosensitive region;
a third semiconductor region 15, wherein a part of the structure of the third semiconductor region 15 is exposed from the light emitting surface 103 and extends from the light emitting surface 103 to the light incident surface 101, and the third semiconductor region 15 is located in an edge region of the substrate 10;
The isolation region is disposed between the first semiconductor region 11 and the third semiconductor region 15, and the light-condensing region covers the surfaces of the isolation region and the third semiconductor region 15.
In this embodiment, the material of the substrate 10 may be a silicon wafer, or may be a germanium substrate 10, a germanium-silicon substrate 10, an indium gallium arsenic substrate 10, a gallium arsenide substrate 10, a silicon carbide substrate 10, or the like, which is not limited herein.
The substrate 10 includes a light entrance surface 101 and a light exit surface 103 formed with opposite and parallel arrangement. Of course, the light entrance surface 101 and the light exit surface 103 may be understood as being substantially parallel, i.e. they are arranged in parallel, and may include that there is a partial non-parallelism between the two surfaces due to machining errors. The light may enter from the light entrance surface, pass through the substrate 10, and exit from the light exit surface. The depth direction of the avalanche photodiode is defined as the direction from the light entrance surface 101 to the light exit surface 103, and the direction parallel to the light entrance surface 101 is the lateral direction.
The substrate 10 is doped with an impurity element, for example, N-type or P-type, in the substrate 10. The doping concentration of each location of the substrate 10 may be the same, or a gradient design may be performed, which is not limited herein. In the present embodiment, the doping types of the substrate 10, the first semiconductor region 11, the second semiconductor region 13, the third semiconductor region 15, and the isolation region are all different. Taking the doping type of the substrate 10 as P-type as an example. That is, P-type epitaxial silicon is formed on the surface of a P-type silicon wafer by chemical vapor deposition or molecular beam epitaxy, a heavily doped first semiconductor region 11 is formed over the substrate 10 by doping a higher concentration of a group V element, for example, non-metal phosphorus (P) or metal arsenic (As), etc., a cathode ohmic contact is formed, and then a group III element, for example, non-metal boron (B) or metal gallium (Ga), may be lightly doped at a certain depth position on the basis of the substrate 10 to form a third semiconductor region 15, which is P-Well (PW) for short, an anode ohmic contact. The doping method may be ion implantation, thermal diffusion, or the like, and is not limited herein. The partial structure of the first semiconductor region 11 exposed on the light emitting surface 103 means that one surface of the first semiconductor region 11 is exposed on the light emitting surface 103, which is not covered with other materials.
In this embodiment, the isolation region may be formed by trench etching and filling polysilicon or tungsten metal or the like in the trench, and the isolation region is used to function as a spacer pixel. Alternatively, the isolation region may be a deep trench or a shallow trench. The isolation region extends from the light emitting surface 103 towards the light entering surface 101, and is arranged around the first semiconductor region 11 and the third semiconductor region 15, so that edge breakdown in advance can be effectively restrained, and center breakdown efficiency is ensured.
In an embodiment of the present invention, the first semiconductor region 11 includes a first doped region 111 and a second doped region 113, a surface of the first doped region 111 is exposed at the light emitting surface 103 and extends toward the light incident surface 101, the second doped region 113 is disposed around the first doped region 111, a portion of the second doped region 113 is exposed at the light emitting surface 103, the second doped region 113 extends from the light emitting surface 103 toward the light incident surface 101, and the second doped region 113 is in contact with the second semiconductor region 13.
In one embodiment of the present invention, the ion concentration doped at different locations in the first semiconductor region 11 is different, for example, by doping a group V element, for example, non-metal phosphorus (P) or metal arsenic (As), etc., over the second semiconductor region 13 to form a second doped region 113 (NW), on the basis of NW, doping a group V element with a higher concentration, thereby forming a heavily doped first doped region 111 (n+), the first doped region 111 being formed with a cathodic ohmic contact. The partial structure of the first doped region 111 exposed on the light-emitting surface 103 means that one surface of the first doped region 111 is exposed on the light-emitting surface 103, which is not covered with other materials. The second doped region 113 partially exposed on the light-emitting surface 103 also means that one surface of the second doped region is exposed on the light-emitting surface 103, which is not covered with other materials, and the second doped region 113 is disposed around the first doped region 111. The surface of the second doped region 113 contacting the second semiconductor region 13 is formed with a first PN junction, and in this region, the second doped region and the first doped region have an overlapping portion in the lateral direction, so that the first PN junction is cooperatively formed, and breakdown can occur at the junction of the second doped region and the second doped region.
In an embodiment of the present invention, the third semiconductor region 15 includes a third doped region 151 and a fourth doped region 153, a part of the third doped region 151 from the third doped region 151 is exposed at the light emitting surface 103, the third doped region 151 extends from the light emitting surface 103 to the light incident surface, a part of the fourth doped region 153 is exposed at the light emitting surface 103, the fourth doped region 153 is disposed around the third doped region 151, and the fourth doped region 153 extends from the light emitting surface 103 to the light incident surface 101.
In this embodiment, a third semiconductor region 15, which is a P-Well (PW) is then formed by lightly doping a group III element, such as a non-metallic boron (B) element or metallic gallium (Ga), at a depth near the edge of the substrate 10. Wherein the ion concentrations of the third doped region 151 and the fourth doped region 153 are different.
The invention also provides a preparation method of the single photon avalanche diode, which comprises the following steps:
Depositing an insulating light-transmitting layer 21 on the light-emitting surface 103 of the device body 100;
Etching is performed on the surface of the insulating light-transmitting layer 21 so that the insulating light-transmitting layer 21 corresponds to the upper side of the first semiconductor region 11 to form a plane 211, and the insulating light-transmitting layer 21 corresponds to the upper side of the third semiconductor region 15 and the isolation region to form an inclined plane 213;
A metal reflecting layer 23 is deposited on the surface of the insulating transparent layer 21, and the metal reflecting layer 23 and the insulating transparent layer 21 form a light-condensing region in correspondence with the inclined surface 213.
In one embodiment of the present invention, the device main body 100 of the single photon avalanche diode may adopt an existing structure, and by optimizing the reflective structure 20 on the surface of the device main body 100, the light reflected by the reflective structure 20 is not uniformly emitted to the inside of the device, but the emitted light of the edge region and the isolation region is converged into the photosensitive region located in the center, so that the photosensitive region can obtain more illumination, the wasted light in the existing scheme is effectively utilized, the utilization rate of the light is increased, the number of generated carriers is multiplied, and the photon detection efficiency is improved. Of course, the device main body 100 of the single photon avalanche diode can also adopt a new structure, and the reflection structure 20 on the surface of the device main body 100 adopting the new structure is optimized, so that the photon detection efficiency of the single photon avalanche diode is improved.
The transparent layer 21 is made of transparent material, and the transparent material includes one or more of silicon oxide, silicon nitride and transparent glue, and the transparent material is usually an insulating material, so as to avoid affecting the electrode. The light-transmitting material may form a film layer with a certain thickness on the light-emitting surface 103, thereby increasing the travel of the light and providing a necessary distance for reflecting and converging the light. The thickness of each position in the light-transmitting layer 21 is not the same, and the thickness of the flat surface 211 is greater than the thickness of the inclined surface 213. In addition, the thickness of the inclined surface 213 is uniformly changed, so that the converged light is uniformly changed, the light change of the photosensitive area is relatively uniform, and the occurrence of bright and dark spots is avoided.
In this embodiment, the insulating transparent layer 21 may be formed by depositing one or more layers of transparent material with uniform thickness by vapor deposition to form a flat insulating transparent layer 21 on the light-emitting surface 103 of the device main body 100, and then etching the deposited insulating transparent material by etching above the insulating transparent layer 21 corresponding to the isolation region and the third semiconductor region 15, so that the outer edge of the transparent material has an inclined surface 213. One end of the inclined surface 213 is directly connected to the light emitting surface 103, and the other end is connected to the flat surface 211 such that the inclined surface 213 surrounds the outer periphery of the flat surface 211 structure. The inclined surface 213 forms an angle θ with the light emitting surface 103 between the angle θ, so that the reflection range of the light condensing area can be increased, and the light waste in the edge area can be avoided. The reflective layer 23 is made of metal, and the reflective layer 23 is directly deposited on the side of the light-transmitting layer 21 away from the light-emitting surface 103 by vapor deposition. It will be appreciated that the reflective layer 23 is opaque and reflects light. Since the light-transmitting layer 21 is formed with the plane 211 and the inclined plane 213, the reflecting surface of the reflecting layer 23 is also formed with the plane 211 and the inclined plane which are consistent with the light-transmitting layer 21, the plane 211 can reflect the light rays emitted from the photosensitive region, and the inclined plane can reflect and collect the light rays emitted from the edge region and the isolation region, so that the reflected light rays are collected to the photosensitive region, and the light utilization rate is improved. It should be noted that, the projection of the plane 211 of the light-transmitting layer 21 on the light-emitting surface 103 can extend to the outside of the photosensitive region, and the width of the photosensitive region is slightly larger, so as to ensure that the light emitted from the photosensitive region can be uniformly reflected by the plane 211 of the reflective layer 23.
The invention also provides a photoelectric detector, which comprises one or more single photon avalanche diodes, wherein the specific structure of the single photon avalanche diode refers to the embodiment, and the single photon avalanche diode adopts all the technical schemes of all the embodiments, so that the photoelectric detector at least has all the beneficial effects brought by the technical schemes of the embodiments, and the description is omitted herein. Wherein, a plurality of single photon avalanche diodes are arranged in an array.
The foregoing description of the preferred embodiments of the present invention should not be construed as limiting the scope of the invention, but rather should be understood to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the following description and drawings or any application directly or indirectly to other relevant art(s).
Claims (10)
1. A single photon avalanche diode, comprising:
The light-emitting device comprises a device main body, a light incident surface and a light emergent surface which are oppositely arranged, wherein a photosensitive area is further formed in the device main body, the photosensitive area extends from the light emergent surface to the direction of the light incident surface and is positioned at the central position of the device main body, the photosensitive area is provided with a first semiconductor area and a second semiconductor area which are downwards overlapped from the light emergent surface, the device main body further comprises an edge area which is annularly arranged at the outer side of the central position, the edge area is provided with a third semiconductor area, and an isolation area is further formed between the photosensitive area and the edge area;
The reflecting structure comprises a light-transmitting layer and a reflecting layer, the light-transmitting layer covers the light-emitting surface, a plane and an inclined plane which are connected are formed on the surface of the light-transmitting layer, which faces away from the light surface, the plane is positioned above the first semiconductor region, the inclined plane is positioned above the isolation region and the third semiconductor region, the reflecting layer covers one side of the light-transmitting layer, which faces away from the light-emitting surface, and a light-gathering region is formed in the area of the light-transmitting layer and the reflecting layer, which corresponds to the inclined plane;
The light is emitted from the light incident surface and is emitted from the light emergent surface, the reflecting structure reflects the light back to the inner side of the device main body, and the light gathering area is used for gathering the light emitted from the outer side of the light sensing area into the light sensing area.
2. The single photon avalanche diode according to claim 1, wherein said inclined surface forms an angle θ with said light exit surface of 15 ° or less θ or 45 °.
3. The single photon avalanche diode according to claim 1, wherein a projection of a plane of said light transmitting layer onto said light exit surface extends outside said photosensitive region.
4. The single photon avalanche diode according to claim 1, wherein the material of the light-transmitting layer comprises one or more of silicon oxide, silicon nitride, and transparent glue;
The reflecting layer is made of metal.
5. The single photon avalanche diode according to any one of claims 1 to 4, wherein said device body comprises:
A substrate, wherein the light incident surface and the light emergent surface are respectively formed on two opposite surfaces of the substrate;
the partial structure of the first semiconductor region is exposed on the light emergent surface and extends from the light emergent surface to the light incident surface, and the first semiconductor region is positioned at the center of the substrate;
The second semiconductor region is arranged on one side of the first semiconductor region, which is away from the light emitting surface, and extends from the light emitting surface to the light entering surface, a first PN junction is formed between the first semiconductor region and the second semiconductor region, and the first semiconductor region and the second semiconductor region form the photosensitive region;
and part of the structure of the third semiconductor region is exposed on the light emergent surface and extends from the light emergent surface to the light incident surface, and the third semiconductor region is positioned in the edge region of the substrate.
6. The single photon avalanche diode according to claim 5, wherein the first semiconductor region comprises a first doped region and a second doped region, wherein a surface of the first doped region is exposed from the light emitting surface and extends toward the light incident surface, the second doped region is annularly arranged around the first doped region, a part of the structure of the second doped region is exposed from the light emitting surface, the second doped region extends from the light emitting surface to the light incident surface, and the second doped region is in contact with the second semiconductor region.
7. The single photon avalanche diode according to claim 6, wherein said third semiconductor region comprises a third doped region and a fourth doped region, wherein a portion of said third doped region is exposed at said light exit surface from said light exit surface, a portion of said third doped region is exposed at said light entrance surface from said light exit surface, a portion of said fourth doped region is surrounded around said third doped region, and said fourth doped region extends from said light exit surface in a direction of said light entrance surface.
8. The single photon avalanche diode according to claim 6, further comprising a first electrode and a second electrode disposed on said light exit surface, said first electrode being connected to said first semiconductor region, said second electrode being connected to said third semiconductor region.
9. A method of manufacturing a single photon avalanche diode according to any of claims 1 to 8, comprising the steps of:
Depositing an insulating light-transmitting layer on the light-emitting surface of the device main body;
etching the surface of the insulating light-transmitting layer to enable the insulating light-transmitting layer to correspond to the upper side of the first semiconductor region to form a plane, and enabling the insulating light-transmitting layer to correspond to the upper side of the third semiconductor region and the upper side of the isolation region to form an inclined plane;
And depositing a metal reflecting layer on the surface of the insulating light-transmitting layer, and forming a light-gathering area in the area of the metal reflecting layer and the insulating light-transmitting layer corresponding to the inclined surface.
10. A photodetector comprising a single photon avalanche diode according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311176807.6A CN119630078A (en) | 2023-09-12 | 2023-09-12 | Single photon avalanche diode, preparation method thereof and photoelectric detector |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311176807.6A CN119630078A (en) | 2023-09-12 | 2023-09-12 | Single photon avalanche diode, preparation method thereof and photoelectric detector |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN119630078A true CN119630078A (en) | 2025-03-14 |
Family
ID=94902422
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311176807.6A Pending CN119630078A (en) | 2023-09-12 | 2023-09-12 | Single photon avalanche diode, preparation method thereof and photoelectric detector |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN119630078A (en) |
-
2023
- 2023-09-12 CN CN202311176807.6A patent/CN119630078A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US12113078B2 (en) | Photodetector | |
| EP2267795A2 (en) | Avalanche photodiode | |
| US11201184B1 (en) | Image sensing devices with reflector arrays | |
| US7888765B2 (en) | Optical semiconductor device | |
| US20140319464A1 (en) | Light receiving element and method for manufacturing same | |
| EP3544064B1 (en) | Photodetector and light detection and ranging | |
| US10636933B2 (en) | Tilted photodetector cell | |
| KR102363563B1 (en) | semiconductor photodetector | |
| US10971643B2 (en) | Implementation of an optimized avalanche photodiode (APD)/single photon avalanche diode (SPAD) structure | |
| US20130153962A1 (en) | Avalanche photo diode and method of manufacturing the same | |
| JP2014003083A (en) | Photodiode array | |
| CN114203852A (en) | Single-photon avalanche diodes and photodetector arrays | |
| US7696593B2 (en) | PIN-type photo detecting element with three semiconductor layers, and window semiconductor layer having controlled thickness | |
| JP4856031B2 (en) | Avalanche photodiode | |
| EP0589024A1 (en) | Low capacitance x-ray radiation detector | |
| AU2023258334A1 (en) | Photovoltaic cell and photovoltaic module | |
| CN103904152A (en) | Photoelectric detector and manufacturing method thereof and radiation detector | |
| KR101371401B1 (en) | Avalanche photodiode and method of forming the same | |
| CN119630078A (en) | Single photon avalanche diode, preparation method thereof and photoelectric detector | |
| EP0522746B1 (en) | Semiconductor photodetector device | |
| US20060213551A1 (en) | Semiconductor photodetector and method for manufacturing same | |
| CN102263162A (en) | A flip-chip structure avalanche photodiode and its array preparation method | |
| KR101762431B1 (en) | Silicon photomultiplier having ree crosstalk structure | |
| JP3427125B2 (en) | Semiconductor device with optical lens function | |
| US20240395955A1 (en) | Photosensitive Element and Assembly Method Thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination |