Impact of oxide thickness on the density distribution of near-interface traps in 4H-SiC MOS capacitors. (16th May 2018)

• Record Type: Journal Article
• Authors: Zhang, Xufang; Okamoto, Dai; Hatakeyama, Tetsuo; Sometani, Mitsuru; Harada, Shinsuke; Iwamuro, Noriyuki; Yano, Hiroshi
• Is Part Of: Japanese journal of applied physics. Volume 57:Number 6(2018)Supplement 3
• Publication Date: 2018-05-16
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.57.06KA04
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: The impact of oxide thickness on the density distribution of near-interface traps (NITs) in SiO2 /4H-SiC structure was investigated. We used the distributed circuit model that had successfully explained the frequency-dependent characteristics of both capacitance and conductance under strong accumulation conditions for SiO2 /4H-SiC MOS capacitors with thick oxides by assuming an exponentially decaying distribution of NITs. In this work, it was found that the exponentially decaying distribution is the most plausible approximation of the true NIT distribution because it successfully explained the frequency dependences of capacitance and conductance under strong accumulation conditions for various oxide thicknesses. The thickness dependence of the NIT density distribution was also characterized. It was found that the NIT density increases with increasing oxide thickness, and a possible physical reason was discussed.