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: | 1-七月-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 |
顯示於類別: | 期刊論文 |