Deuterium etching of the Si-rich SiC(0001) (3 x 3) surface reconstruction

The low-energy electron diffraction (LEED) pattern of the SiC(0001) (3 x 3) surface reconstruction undergoes a change from (3 x 3) to (1 x 1) upon exp osure to atomic hydrogen (and deuterium). Using high-resolution electron en ergy loss spectroscopy (HREELS), Auger electron spectroscopy (AES) and LEED , we have determined that this change is due to disordering and etching of the uppermost Si layers. With increasing deuterium exposure at 320 K, deple tion of the Si adlayer and formation of SiD surface species is observed. At high deuterium exposure, observation of the C-D stretch mode indicates the onset of bulk silicon carbide etching. SiD2 and SiD3 surface species, know n intermediates in the Si etching process, are observed with deuterium expo sure at 180 K. (C) 2000 Elsevier Science B.V. All rights reserved.