Epitaxial graphene growth on 4H‐SiC (0001) with precisely controlled step‐ terrace surface by high temperature annealing above 2000 °C in UHV

Abstract

Abstract Surface graphitization of 4H‐SiC (0001) at high temperature up to 2100 °C in ultra high vacuum (UHV) was observed for the first time in this study. From precisely controlled SiC step‐terrace surfaces, uniform graphitized surface morphologies with large terraces appeared at anneal temperatures above 2000 °C. All the high‐temperature processes were performed by using a newly constructed all metal chamber which enables to elevate temperature from 800 °C to 2000 °C within a minute in UHV. Initial step‐terrace surfaces consisting of 1.0nm step height were achieved on 4H‐SiC (0001) by utilizing newly proposed Si‐vapor etching in a “semi‐closed” TaC container. By estimations of Raman spectra, mainly bilayer graphene was obtained at temperatures from 1600 °C to 2100 °C. Estimation of Raman spectra also indicated that larger domain size graphene grows at higher temperatures, which coincides well with the results of morphological changes observed by AFM measurements. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)