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The Effect of Inductively Coupled Plasma Etching on the I – V Curves of the Avalanche Photodiode with GaN/AlN Periodically Stacked Structure
Author(s) -
Wu Xingzhao,
Wang Lai,
Hao Zhibiao,
Han Yanjun,
Sun Changzheng,
Xiong Bing,
Wang Jian,
Li Hongtao,
Luo Yi,
Brault Julien,
Khalfioui Mohamed Al,
Nemoz Maud,
Li Mo,
Kang Jianbin,
Li Qian
Publication year - 2019
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201900655
Subject(s) - materials science , inductively coupled plasma , etching (microfabrication) , dry etching , fabrication , surface roughness , optoelectronics , nitride , reactive ion etching , volumetric flow rate , avalanche photodiode , plasma , analytical chemistry (journal) , surface finish , dark current , layer (electronics) , nanotechnology , optics , composite material , chemistry , photodetector , quantum mechanics , medicine , physics , alternative medicine , pathology , chromatography , detector
Inductively coupled plasma (ICP) is widely used in dry etching of III‐nitride materials, wherein the etching parameters of GaN and AlN are very different. Herein, the ICP dry etching process parameters of GaN/AlN periodically stacked structure (PSS) for avalanche photodiode (APD) fabrication are intensively studied and optimized. The flow rate ratio of Cl 2 /BCl 3 /Ar plasma, bias voltage, and the GaN‐to‐SiN x selectivity of ICP etching are optimized to achieve excellent surface morphology and nearly vertical sidewalls. It is found that the etching rate and the etched surface roughness of GaN/AlN material are significantly influenced by the flow rate of Cl 2 . After optimizing the etching procedure, the root‐mean‐square roughness of the etched surface is measured to be 1.46 nm, which is close to the as grown surface. By using the optimized ICP dry etching in the fabrication of the GaN/AlN PSS APD, the dark current is suppressed from 3.6 to 8.2 × 10 −3 A cm −2 at −90 V.