Compositional Changes in Surface Region of Sic Single-Crystal Due to Hydrogen and Helium Ion Irradiation

ABSTRACT

Compositional changes in the surface region of single-crystal SiC(0001) due to heat treatment and light ion irradiation in the keV range were studied with the use of AES. The heat treatment at 1000°C formed a carbon enriched layer with a thickness of 20 Å on the top surface and a carbon depletion layer below this layer. Both hydrogen and helium ion irradiation caused depletion of silicon atoms in the near surface region and depletion of carbon atoms in the deeper surface region. TRIM computations revealed that in the process of slowing down of incident hydrogen ions, their kinetic energy was transfered preferentially to silicon atoms in the near surface region and to carbon atoms in the deeper surface region. This tendency explains the formation of each altered layer.