Effects of remote hydrogen plasma on chemical bonding features and electronic states of 4H-SiC(0001) surface

Abstract

We have demonstrated a novel dry cleaning process for the 4H-SiC surface using remote hydrogen plasma (H2-RP). The effects of H2-RP exposure on the chemical structures and electronic states of the wet-cleaned 4H-SiC surface have been evaluated by X-ray photoelectron spectroscopy (XPS) and total photoelectron yield spectroscopy (PYS). XPS shows that H2-RP exposure is effective in removing contaminants from the 4H-SiC surface. PYS indicates that the defect states at the surface are generated after the H2-RP exposure and such generated defect states are drastically decreased by annealing at 850 °C. The combination of H2-RP exposure with the subsequent annealing is found to be effective in 4H-SiC surface cleaning.