Competitive growth between deposition and etching in 4H-SiC CVD epitaxy using quasi-hot wail reactor

Deposition temperature dependence of deposition rate is studied quantitatively in 4H-SiC CVD under hydrogen atmosphere in the temperatures range from 1470 to 1720 degreesC. When process temperature is higher than 1620 degreesC, etching rate is comparative to the growth rate and reduction of deposition rate occurs. At 1720 degreesC, etching rate was so large as 33 mum/hr and large amount of source gas supply was required to attain deposition. The reduction of deposition rate is simply deduced from etching rate observed in hydrogen atmosphere. The maximum deposition rate for samples with mirror surface increases with deposition temperature. High growth rate of about 30 mum/hr is obtained when deposition temperature is 1720 degreesC. However, etching rate is suggested to be larger than the maximum epitaxial growth rate when deposition temperature is higher than 1800 degreesC due to the large temperature dependence of etching rate.