SUPPRESSION OF ETCH PIT AND HILLOCK FORMATION ON CARBONIZATION OF SI SUBSTRATE AND LOW-TEMPERATURE GROWTH OF SIC

A carbonized layer on a Si substrate was formed with hot-wall type LPCVD. The Si substrate was heated up to 1020-degrees-C at various C2H2 partial pressures from 1.0 to 18 mTorr. A lot of etch pits and hillocks were observed on the carbonized substrate at lower C2H2 partial pressures, which are supposed to be formed by Si migration via the SiC layer. Formation of etch pits and hillocks was suppressed with increasing C2H2 partial pressure because of sealing-off the Si diffusion via the SiC layer. After carbonization of Si the substrate at 8.1 mTorr C2H2 partial pressure at 1020-degrees-C, SiH2Cl2 and C2H2 were alternately introduced at 1000-degrees-C to grow SiC films. The growth rate of SiC was 8 angstrom/cycle; this seems to imply that the growth might occur by atomic level controlled surface reactions.