Thermodynamic Analysis of Blanket and Selective Epitaxy of Sic on Si and SiO 2 Masked Si

Thermodynamic analysis was conducted to determine the conditions necessary for the selective epitaxial growth (SEG) of SiC on SiO 2 masked Si substrates, and these results were compared to blanket SiC epitaxy on plain Si. For blanket SiC epitaxy, proper deposition conditions leading to single phase SiC without Si or graphite codeposition were found. For SiC SEG, the additional constraint that no significant SiO 2 mask etching should occur, was considered. Taken in combination, both the SiC deposition and the Si0 2 etching processes were analyzed to ensure meaningful subsequent experiments. All process parameters, i.e., temperature, C/Si, CI/Si and H 2 /Si in the gas mixture significantly affect the growth conditions when epitaxy is possible. Either providing more carbon than silicon in the gas sources or adding HCl helps to suppress Si codeposition. For SiC SEG, lower deposition temperature (e.g. less than 1400 K) should be used to avoid damaging the SiO 2 mask.