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

The low-energy electron diffraction (LEED) pattern of the SiC(0001) (3×3) surface reconstruction undergoes a change from (3×3) to (1×1) upon exposure to atomic hydrogen (and deuterium). Using high-resolution electron energy 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, depletion 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, known intermediates in the Si etching process, are observed with deuterium exposure at 180 K.