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CN-122028525-A - Single photon avalanche diode and manufacturing method thereof, light detector and system

CN122028525ACN 122028525 ACN122028525 ACN 122028525ACN-122028525-A

Abstract

The embodiment of the application provides a single photon avalanche diode, a manufacturing method thereof, a light detector device and a system, wherein a first doping structure is formed on the horizontal surface and the side wall of one side of a second doping structure, a region, adjacent to the second doping structure, of the first doping structure is used for forming an avalanche region, a high field region, adjacent to a corner region, of the second doping structure and the first doping structure is easier to form the avalanche region, namely, an avalanche effect occurs in the edge region of the second doping structure and the first doping structure, so that the probability of generating the avalanche effect is high, and a covering material can provide an electric field for enabling a plurality of photons in the first doping material layer to move from the edge to the center, so that the photon-generated carriers in the first doping material layer can move to the avalanche region, and the charge collection efficiency is improved to a certain extent, so that the device has higher quantum efficiency, and thus higher light detection efficiency.

Inventors

  • YANG YUHUAI
  • TAKATA HIDEKAZU
  • HE ZHIHONG
  • XIE CHENGZHI

Assignees

  • 华为技术有限公司

Dates

Publication Date
20260512
Application Date
20200717

Claims (20)

  1. 1. A single photon avalanche diode, comprising a first doped material layer, a first doped structure, a second doped structure and a capping material; The covering material covers the surface of the first doping material layer, the first doping material layer and the second doping structure are stacked, the first doping structure covers the side wall of the second doping structure and/or the surface of the second doping structure facing the first doping material layer, the doping types of the first doping material layer and the second doping structure are consistent, and the doping type of the first doping structure is opposite to that of the second doping structure.
  2. 2. The single photon avalanche diode according to claim 1, further comprising a third doping structure; When the first doping structure covers a part of the side wall of the second doping structure, which is close to the first doping material layer, the third doping structure is positioned on a part of the side wall of the second doping structure, which is not covered by the first doping structure, or the third doping structure is positioned between the second doping structure and the first doping structure, and a part of the side wall of the second doping structure, which is not covered by the first doping structure; The doping type of the third doping structure is consistent with that of the second doping structure, and the doping concentration is lower than that of the second doping structure.
  3. 3. The single photon avalanche diode according to claim 1or 2, wherein the first doping structure extends longitudinally through the first doping material layer.
  4. 4. The single photon avalanche diode according to any of claims 1-3, wherein said cover material is a fourth doping structure and/or a dielectric layer, said dielectric layer being charged, said fourth doping structure being of opposite doping type to said first doping material layer, said dielectric layer being of the same charging type as the charge type of the multiple photons in said first doping material layer.
  5. 5. The single photon avalanche diode according to any one of claims 1-4, wherein the cap material is connected to a first terminal, the first terminal and the second doping structure being adapted to be connected to different biases, respectively.
  6. 6. The single photon avalanche diode according to any one of claims 1-5, wherein the second doping structure is located in a middle of the first doping material layer, or the second doping structure is located along an edge of the first doping material layer, or the second doping structure is located at a top corner position of the first doping material layer.
  7. 7. The single photon avalanche diode according to any one of claims 1-6, further comprising a substrate; The substrate is sequentially provided with a first doping material layer and a second doping structure from bottom to top; or the substrate is provided with a second doping structure and a first doping material layer from bottom to top.
  8. 8. The single photon avalanche diode according to claim 7, further comprising a microlens layer; The microlens layer is positioned on one side surface far away from the substrate, and the microlens layer is focused between the edge of the first doping material layer and the second doping structure.
  9. 9. The single photon avalanche diode according to claim 8, wherein the microlens layer is an array arrangement of microlenses including convex lenses and/or fresnel lenses.
  10. 10. The single photon avalanche diode according to any one of claims 7-9, further comprising an inverted pyramidal structure located on a side remote from the substrate.
  11. 11. The single photon avalanche diode according to any one of claims 1-10, wherein a cross-sectional area of the second doping structure is smaller than a cross-sectional area of the first doping material layer.
  12. 12. The single photon avalanche diode according to any one of claims 1-11, wherein a doping concentration of the second doping structure is higher than a doping concentration of the first doping material layer.
  13. 13. A method of manufacturing a single photon avalanche diode comprising: Preparing a second doping structure, a first doping structure and a first doping material layer, wherein the doping types of the first doping material layer and the second doping structure are consistent, the first doping structure covers the side wall of the second doping structure and/or the surface of the second doping structure facing the first doping material layer, and the doping type of the first doping structure is opposite to that of the second doping structure; Preparing a covering material, wherein the covering material covers the surface of the first doped material layer.
  14. 14. The method as recited in claim 13, further comprising: Forming a third doping structure; When the first doping structure covers a part of the side wall of the second doping structure, which is close to the first doping material layer, the third doping structure is positioned on a part of the side wall of the second doping structure, which is not covered by the first doping structure, or the third doping structure is positioned between the second doping structure and the first doping structure, and a part of the side wall of the second doping structure, which is not covered by the first doping structure; The doping type of the third doping structure is consistent with that of the second doping structure, and the doping concentration is lower than that of the second doping structure.
  15. 15. The method of claim 13 or 14, wherein the first doping structure extends longitudinally through the first doping material layer.
  16. 16. The method of any of claims 13-15, wherein the second doping structure is located in a middle of the first doping material layer, or the second doping structure is located along an edge of the first doping material layer, or the second doping structure is located at a top corner of the first doping material layer.
  17. 17. The method of any of claims 13-16, wherein a cross-sectional area of the second doping structure is smaller than a cross-sectional area of the first doping material layer.
  18. 18. The method of any of claims 13-17, wherein a doping concentration of the second doping structure is higher than a doping concentration of the first doping material layer.
  19. 19. A light detecting device characterized by comprising a plurality of light detecting units including a logic circuit layer, the single photon avalanche diode according to any one of claims 1 to 12, or a single photon avalanche diode prepared by the method of manufacturing a single photon avalanche diode according to any one of claims 13 to 18, the logic circuit layer being electrically connected to the single photon avalanche diode.
  20. 20. The light detector device of claim 19, wherein the single photon avalanche diodes in different detection cells are isolated by isolation trenches.

Description

Single photon avalanche diode and manufacturing method thereof, light detector and system The present application is a divisional application, the application number of the original application is 202080099985.1, the original application date is the month 17 of 2020, and the whole content of the original application is incorporated by reference into the present application. Technical Field The present application relates to the field of semiconductor manufacturing technology, and in particular, to a single photon avalanche diode, a method for manufacturing the same, a photodetector device, and a system. Background Currently, in many scenarios, a photodetector is used, where the photodetector may receive an optical signal, and the optical signal excites photoelectrons inside the photodetector and is collected, that is, the photodetector may generate a corresponding electrical signal based on the optical signal, so as to implement conversion from the optical signal to the electrical signal. For example, in a laser radar (light detection AND RANGING, lidar) system, a time of flight (ToF) manner may be used to detect an object to be detected, specifically, a radar transmitting system transmits a laser signal, the laser signal is reflected by the object to be detected and then received by a photodetector, and the transmitting time and the receiving time of the laser signal are used to obtain the flight (round trip) time of the laser signal, so that the distance between the laser radar system and the object to be detected (i.e., the depth information of the object to be detected) may be determined, and then the position information of the object to be detected may be obtained. The laser radar system can be applied to vehicles, and with the continuous evolution of the automatic driving technology of the automobile, the demand for the automatic driving level is continuously improved, and the demand for the perception capability of the vehicles is also continuously improved, so that a higher-performance light detector in the laser radar system is required. In addition, the optical detector can also be arranged in other terminals and wearable devices with photoelectric conversion functions. The single photon avalanche diode (single photon avalanche diode, SPAD) is used as a component of a photodetector, and the working principle is that photon-generated carriers (electron hole pairs) generated under the action of optical signals through photoelectric effect are rapidly accelerated when a high electric field region (reverse voltage of PN junction) moves, one or more collisions can occur in the movement process, and secondary and tertiary new electron hole pairs are generated through collision ionization effect to generate avalanche multiplication effect, so that the number of carriers is rapidly increased, and a relatively large photon-generated current is formed. Thus, a single photon avalanche diode can detect very weak photons (on the order of a single photon), sampling and calculating the optical field of an imaged object in time and space. Single photon avalanche diodes are the fundamental device of many optoelectronic devices, whose performance affects the performance of the optoelectronic device. For example, in a direct measurement time of flight (dtif) system, the response capability of a single photon avalanche diode to photons, i.e., the photo detection efficiency (photon detection efficiency, PDE), is critical to the performance of the dtif system, whereas current single photon avalanche diodes are lower in photo detection efficiency because the quantum efficiency (quantum efficiency, QE) tends to be lower in devices with larger avalanche probability (AVALANCHE PROBABILITY) and lower in devices with higher quantum efficiency. Therefore, in order to achieve the performance of the photoelectric device with better performance, the performance of the single photon avalanche diode is urgently required to be improved. Disclosure of Invention In view of the foregoing, a first aspect of the present application provides a single photon avalanche diode, a method for manufacturing the same, a photodetector device and a system, which can improve the light detection efficiency. According to a first aspect of the embodiment of the application, a single photon avalanche diode is provided, and comprises a first doping material layer, a second doping structure, a first doping structure and a covering material, wherein the first doping material layer and the second doping structure are stacked in the longitudinal direction, the cross section of the second doping structure is smaller than that of the first doping material layer, the doping types of the first doping material layer and the second doping structure are consistent, the doping concentration of the second doping structure is higher than that of the first doping material layer, the first doping structure covers the surface of the second doping structure facing the f