Open AccessImpact of etching on the surface leakage generation in mesa-type InGaAs/InAlAs avalanche photodetectors
Author(s) -
Yingjie Ma,
YG Zhang,
Gu Yuan,
Xingyou Chen,
Yue Shi,
Wenliang Ji,
Suping Xi,
Binyang Du,
Xiaoliang Li,
Hengjing Tang,
Yongfu Li,
Jiaxiong Fang
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.007823
Subject(s) - apds , avalanche photodiode , materials science , optoelectronics , dark current , etching (microfabrication) , inductively coupled plasma , leakage (economics) , optics , mesa , indium gallium arsenide , photodetector , gallium arsenide , plasma , detector , nanotechnology , layer (electronics) , programming language , physics , quantum mechanics , computer science , economics , macroeconomics
Effects of mesa etching and geometry on InGaAs/InAlAs avalanche photodiodes (APDs) were investigated by using both wet and inductively coupled plasma (ICP) etching with different mesa shapes as well as etchants. It was found that the mesa geometry had no evident impact on APDs' characteristics regardless of the etching techniques applied. Besides, ICP-etched APDs showed faster punch-through, suppressed premature surface breakdown and lower dark current behaviors compared to the wet-etched devices. Substantially suppressed surface leakage was also observed for ICP-etched devices, showing 1 and 3 orders of magnitude better at room temperature and 77 K respectively, and over 1 order of magnitude higher surface resistivity up to 4×10 7 Ω cm, in comparison to the wet-etched APDs. Introduction of extra hydrogen and Ar plasma in ICP etching led to detrimental effects to APDs' performance by enhancing the tunneling or recombination at surfaces. Those experimental results were clearly interpreted based on the surface state theories.