標題: The variation of ohmic contacts and surface characteristics on p-GaN induced by reactive ion etching
作者: Chang, KM
Cheng, CC
Chu, JY
電子工程學系及電子研究所
Department of Electronics Engineering and Institute of Electronics
公開日期: 1-Jul-2002
摘要: Electron cyclotron resonance (ECR) reactive ion etch (RIE) was used to etch p-type GaN under a chlorine-based plasma. Rapid thermal annealing (RTA) and nitrogen plasma were used as post-RIE treatments to investigate the variation of Ni/Au contacts on p-GaN. RIE deteriorated the contact very much due to the induced nitrogen vacancies and damage on the p-GaN surface. The poor contact was improved by RTA treatment at 700degreesC for 3 min although the current-voltage curve was still nonlinear. The results from X-ray photoelectron spectroscopy (XPS), atomic force microscopy, and grazing incidence X-ray diffraction measurements indicated that RTA at 700degreesC could reconstruct the ordered structure from the damaged p-GaN surface. Annealing at 500 or 900degreesC did not improve the contact due to the high oxygen content of the surface. ECR-N-2 plasma treatment could scarcely improve the contact. XPS and photoluminescence analyses revealed that the nitrogen plasma treatment increased the number of nitrogen vacancies as well as the nitrogen content of a p-GaN surface. These nitrogen atoms did not form tight bonds with GaN, and easily escaped from the surface by annealing. (C) 2002 The Electrochemical Society.
URI: http://dx.doi.org/10.1149/1.1479161
http://hdl.handle.net/11536/28694
ISSN: 0013-4651
DOI: 10.1149/1.1479161
期刊: JOURNAL OF THE ELECTROCHEMICAL SOCIETY
Volume: 149
Issue: 7
起始頁: G367
結束頁: G369
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