PLASMA ETCH VOID FORMED AT THE SIC FILM SI SUBSTRATE INTERFACE

Cubic silicon carbide films are grown on the Si (111) substrate by mea ns of hydrogen plasma sputtering. Formation mechanisms of the hollow v oids at the SIC film/Si substrate interface are studied by varying bot h the film growth temperature from 650 degrees C to 850 degrees C, and the film growth time from 2 s to 55 h. A two-step etching model is pr oposed to explain the formation mechanisms, based on our experimental results. The etching first starts from the point defects, and etch pit s first appear near the Si substrate surface. When this first etching stops due to growth of a SIC film on the first etch pits, subseguent e tching starts around the first etch pits and results in the hollow voi ds at the film/substrate interface at substrate temperatures above 650 degrees C. The depth of the hollow voids becomes constant with growth time after a continuous SiC film is formed over the Si substrate.