Effect of Ar annealing temperature on SiO₂/SiC:SiO₂ densification change causing leakage current reduction

State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, P.R. China

^a e-mail: zzq@uestc.edu.cn

Received: 27 October 2012
Revised: 22 March 2013
Accepted: 29 March 2013
Published online: 30 April 2013

Abstract

The authors investigated the effects of annealing in Ar atmosphere at different temperatures (350–1100 °C) on the densification and leakage current characteristics of thermally oxidized SiO₂ films on n-type 4H-SiC. A strong correlation between densification improvement and leakage current reduction was observed. Densification of the SiO₂ films, which were characterized by spectroscopic ellipsometry, Fouriertransform infrared spectroscopy and atomic force microscopy, can be significantly improved after annealing at moderate temperature (600 °C). The leakage current is decreased by two orders of magnitude of the SiO₂ thin film after annealing at 600 °C. Based on the studies, SiO₂ film of the highest quality can be obtained after annealing at 600 °C. Improvements in the quality of the SiO₂ thin films after annealing at 600 °C may be explained by the consumption and formation of carbon-related and oxygen-related defects during annealing.