Preflow trimethylaluminum treatment effect on GaN growth on SiC with an ultrathin interlayer. (14th April 2016)

• Record Type: Journal Article
• Authors: Sun, Zheng; Nagamatsu, Kentaro; Olsson, Marc; Song, Peifeng; Deki, Manato; Nitta, Shugo; Honda, Yoshio; Amano, Hiroshi
• Is Part Of: Japanese journal of applied physics. Volume 55:Number 5(2016:May)Supplement
• Publication Date: 2016-04-14
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/JJAP.55.05FB06
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: Previously, we reported a growth method for GaN on SiC by metalorganic vapor phase epitaxy. By using a preflow trimethylaluminum treatment, the poor wetting problem of gallium on the SiC surface was alleviated, resulting in a 1.2-µm-thick crack-free GaN grown on an on-axis 6H-SiC(0001) substrate via an ultrathin AlGaN interlayer. In this study, the impact of the preflow trimethylaluminum treatment time is investigated to understand why a crack-free epilayer was realized. To demonstrate the electrical performance of devices formed by our technique, GaN/SiC vertical Schottky barrier diodes were fabricated and compared with GaN/AlN/SiC and GaN/GaN vertical Schottky barrier diodes. Compared with diodes including a high-resistance AlN interlayer, the series resistance of GaN/SiC Schottky barrier diodes incorporating the ultrathin interlayer with 5 s of TMAl treatment showed a marked reduction from 4.0 × 10 7 to 2.0 × 10 −1 Ω·cm 2 . The ultrathin interlayer growth technique is expected to be applied in future GaN/SiC hybrid high-power and high-frequency devices.