Recovery of p-GaN surface damage induced by dry etching for the formation of p-type Ohmic contact. (10th April 2019)

• Record Type: Journal Article
• Authors: He, Junlei; Zhong, Yaozong; Zhou, Yu; Guo, Xiaolu; Huang, Yingnan; Liu, Jianxun; Feng, Meixin; Sun, Qian; Ikeda, Masao; Yang, Hui
• Is Part Of: Applied physics express. Volume 12:Number 5(2019)
• Publication Date: 2019-04-10
• Subjects: ohmic contact -- p-GaN -- etching damage -- nitrogen vacancy -- XPS; Physics -- Periodicals; Technology -- Periodicals; 621.05
• DOI: 10.7567/1882-0786/ab13d7
• Languages: English
• ISSNs: 1882-0778

Abstract

Abstract: P-type Ohmic contact on the dry-etched p-GaN surface is highly desired for various device applications with the p-GaN buried underneath by an epitaxial layer or a dielectric layer. However, GaN dry etching process usually induces surface damage and inevitably degrades the p-type Ohmic contact performance. In this work, p-type Ohmic contact with a low specific resistivity has been successfully realized on a dry-etched p-GaN surface by using a wet chemical etching combined with a thermal treatment in NH3 /N2 ambient. Furthermore, the recovery mechanism of the p-GaN surface damage was studied through an in-depth surface characterization by atomic force microscopy and X-ray photoelectron spectroscopy.