Characterization of the 6H-SiC 0001/surface and the interface with Ti layer with the Schottky limit

The Tir6H-SiC 0001.interface with the Schottky limit and the SiC surfaces before metallization are investigated using low energy electron microscopy LEED., Auger electron spectroscopy AES., X-ray photoemission spectroscopy XPS., scanning tunneling microscopy STM., and cross-sectional transmission electron microscopy TEM.. The surface to form the resultant Schottky limit is prepared by dipping the SiC wafer into pure boiling water of ;1008C for 10 min. The surface has the 1=1 surface reconstruction with a small amount of oxygen less than 5%, suggesting that the surface is mainly terminated by hydrogen. In the STM analysis, we found that oxygen strongly terminates atomic step edges, which leads to the drastic reduction of the resultant density of interface states after metallization at room temperature. Epitaxial and commensurate relations between a Ti layer and the SiC substrate without any interface layer were found by cross-sectional TEM analysis. The observed commensurate interface indicates that the surface hydrogen terminator on the terraces was desorbed after metallization. q2000 Elsevier Science B.V. All rights reserved.