Analysis of Heat-Treated 6H-SiC(0001) Surface Using Scanning Tunneling Microscopy

Abstract
A scanning tunneling microscopy in ultrahigh vacuum (UHV) has been used to study hexagonal (6H) silicon carbide (0001)Si face prepared by heat treatment. √3 ×√3, 6 ×6 and 3 ×3 reconstructions were observed above 1100°C. With increasing heat-treatment temperature, surface structure changed drastically and step heights decreased to that of a double layer. The 6 ×6 and 3 ×3 reconstructions can be explained as the structure of a graphite layer on the SiC surface and as the structure proposed by Kaplan, respectively.