Selective epitaxial growth of 4H-SiC at reduced temperatures using halo-carbon precursor

摘要

Selective homoepitaxial growth of 4H-SiC polytype at temperatures down to 1300℃ was investigated using novel halo-carbon epitaxial growth technique. More than three times higher growth rate than in blanket epitaxy without morphology degradation was due to the local loading effect, which demonstrated that the growth rate of SiC homoepitaxy at low temperatures is limited by the gas-phase reaction mechanisms rather than surface mechanisms. It was established that the step-flow growth without undesirable nucleation may be maintained at growth rates in excess of 6 μm/h. Strong dependence of the growth rate on the ratio of the seed area to the masked area indicated that the growth rate is predominantly mass transport limited. Facet formation and conditions for suppressing defect generation at the mesa walls were investigated.