Surface-Localized 15R Formation on 4H-SiC (0001) Si-Face by Laser Annealing for Power N-Type MOSFETs

Abstract

A SiC MOSFET fabricated on a thin 15R-SiC layer on top of a 4H-SiC would benefit from both the higher inversion channel mobility of 15R-SiC and higher bulk mobility of 4H-SiC. In this work, a method based on Al implantation followed by UV laser annealing (UV-LA) to form 15R-SiC on 4H is shown. Evaluation of crystal quality and SiC polytype identification are performed by Raman spectroscopy. We show that UV-LA is able to grow 15R-SiC and cure the crystal damaged by ion implantation until a level close to the pristine substrate. This opens new perspectives for fabrication of SiC n-type MOSFETs.