Avalanche photodiode sensor and sensor device

Patent metadata

Field	Value
Publication number	US-2022165902-A1
Application number	US-202017593698-A
Country	US
Kind code	A1
Filing date	Feb 20, 2020
Priority date	Apr 5, 2019
Publication date	May 26, 2022
Grant date	—

Abstract

To reduce a variation in the characteristics of avalanche photodiode sensors. An avalanche photodiode sensor includes a first semiconductor region, a second semiconductor region, a low-impurity-concentration region, a first contact region, and a second contact region. The first semiconductor region is disposed on a surface of a semiconductor substrate. The second semiconductor region is disposed below the first semiconductor region and has a different conductivity type from the first semiconductor region. The low-impurity-concentration region is disposed adjacent to the second semiconductor region. The first contact region is disposed on the surface of the semiconductor substrate to be adjacent to the first semiconductor region and has electrodes connected thereto. The second contact region is disposed adjacent to the low-impurity-concentration region and has electrodes connected thereto.

First claim

1 . An avalanche photodiode sensor comprising:
a first semiconductor region disposed on a surface of a semiconductor substrate; a second semiconductor region disposed below the first semiconductor region and having a different conductivity type from the first semiconductor region; a low-impurity-concentration region disposed adjacent to the second semiconductor region; a first contact region disposed on the surface of the semiconductor substrate to be adjacent to the first semiconductor region and having an electrode connected thereto; and a second contact region disposed adjacent to the low-impurity-concentration region and having an electrode connected thereto.

2 . The avalanche photodiode sensor according to claim 1 , wherein the second contact region is disposed on the surface of the semiconductor substrate.

3 . The avalanche photodiode sensor according to claim 2 , further comprising an isolation region disposed between the first contact region and the second contact region.

4 . The avalanche photodiode sensor according to claim 1 , wherein the first contact region has a deeper bottom portion than a bottom portion of the second semiconductor region.

5 . The avalanche photodiode sensor according to claim 1 , further comprising a separation region for separating subject avalanche photodiode sensors in the semiconductor substrate.

6 . The avalanche photodiode sensor according to claim 5 , further comprising a charge accumulation layer disposed adjacent to the separation region to accumulate carriers of the same conductivity type as the second contact region.

7 . The avalanche photodiode sensor according to claim 6 , wherein the charge accumulation layer is disposed adjacent to the second contact region.

8 . The avalanche photodiode sensor according to claim 6 , wherein the charge accumulation layer is further disposed on a back surface different from the surface of the semiconductor substrate.

9 . The avalanche photodiode sensor according to claim 1 , wherein the first contact region is formed in a shape surrounding the first semiconductor region.

10 . The avalanche photodiode sensor according to claim 1 , further comprising an on-chip lens that collects incident light in the low-impurity-concentration region.

11 . The avalanche photodiode sensor according to claim 10 , wherein the on-chip lens is disposed on a back surface different from the surface of the semiconductor substrate.

12 . A sensor device comprising:
an avalanche photodiode sensor; and a processing circuit that processes a signal generated on the basis of a current flowing through the avalanche photodiode sensor according to an incident light, the avalanche photodiode sensor comprising: a first semiconductor region disposed on a surface of a semiconductor substrate; a second semiconductor region disposed below the first semiconductor region and having a different conductivity type from the first semiconductor region; a low-impurity-concentration region disposed adjacent to the second semiconductor region; a first contact region disposed on the surface of the semiconductor substrate to be adjacent to the first semiconductor region and having an electrode connected thereto; and a second contact region disposed adjacent to the low-impurity-concentration region and having an electrode connected thereto.

13 . The sensor device according to claim 12 , wherein the processing circuit performs a process of detecting a distance to an object on the basis of the signal generated when a reflected light based on light from the object irradiated with the light is incident on the avalanche photodiode sensor.

Assignees

• Sony Semiconductor Solutions Corp

Inventors

• Okazaki Mutsumi
• Otake Yusuke

Classifications

• G01S7/4863

  Detector arrays, e.g. charge-transfer gates · CPC title

• G01S7/4816

  of receivers alone · CPC title

• H10F77/933

  for devices having potential barriers · CPC title

• H10F77/14

  Shape of semiconductor bodies; Shapes, relative sizes or dispositions of semiconductor regions within semiconductor bodies · CPC title

• H10F39/807 Primary

  Pixel isolation structures · CPC title