# US 9,520,526 B2 · Manufacturing method of avalanche photodiode

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- Number: US 9,520,526 B2
- Document ID: US9520526B2
- Status: Granted
- Kind: B2
- Application number: 14/830,447
- Filed: 2015-08-19
- Published: 2016-06-02
- Granted: 2016-12-13
- Earliest claimed: 2014-11-28
- Assignees: Mitsubishi Electric Corporation
- Applicants: Mitsubishi Electric Corporation
- Inventors: Harunaka Yamaguchi; Susumu Hatakenaka
- Web page: https://patentgrep.com/patent/US9520526B2

## CPC

- H10F 71/1272: {comprising at least three elements, e.g. GaAlAs or InGaAsP}
- H10F 30/225: the potential barrier working in avalanche mode, e.g. avalanche photodiodes
- H10F 30/2255: {in which the active layers form heterostructures, e.g. SAM structures}
- Y02E 10/544: Solar cells from Group III-V materials
- H10F: INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A manufacturing method of an avalanche photodiode includes: forming a p-type field relaxation layer on a substrate; forming a cap layer on the p-type field relaxation layer; and forming a light absorbing layer on the cap layer, wherein a carbon is doped in the p-type field relaxation layer as a p-type dopant, the p-type field relaxation layer contains Al in a crystal composition, and a temperature-rise process from a growth temperature of the cap layer to a growth temperature of the light absorbing layer is performed in an inactive gas atmosphere without introducing a group V raw material.

## Claims

### Claim 1

A manufacturing method of an avalanche photodiode comprising:
forming a p-type field relaxation layer on a substrate;
forming a cap layer on the p-type field relaxation layer; and
forming a light absorbing layer on the cap layer,
wherein a carbon is doped in the p-type field relaxation layer as a p-type dopant,
the p-type field relaxation layer contains Al in a crystal composition, and
a temperature-rise process from a growth temperature of the cap layer to a growth temperature of the light absorbing layer is performed in an inactive gas atmosphere without introducing a group V raw material.

### Claim 2 (depends on 1)

The manufacturing method of the avalanche photodiode of claim 1, wherein a ratio of hydrogen to carbon contained in the p-type field relaxation layer after the temperature-rise process is 0.10 to 0.13.

### Claim 3 (depends on 1)

The manufacturing method of the avalanche photodiode of claim 1, wherein after a temperature is raised to the growth temperature of the light absorbing layer in the temperature rise process, annealing is not performed, and growth of the light absorbing layer is started.