抄録
The mechanism of 3C-SiC heteroepitaxial growth on Si(001) substrates has been explored using a hot-wall-type low pressure reactor, into which SiH_2Cl_2 and C_2H_2 are fed alternately. To minimize undesirable effects arising from the lattice miss-match that inevitably occurs at the boundary between Si and 3C-SiC, C_2H_2 was used to implement surface carbonization for Si substrates prior to the 3C-SiC growth process. During heating of Si substrates from 500℃ to 1000℃ or higher in the C_2H_2 environment, a single crystalline carbonized layer (3C-SiC) was formed. Following the carbonization of the Si substrate surface, Si H_2Cl_2 and C_2H_2 were alternately fed into the reaction tube to grow epitaxial 3C-SiC film. The growth rate of 3C-SiC was determined from the nummber of Si atoms taken into the surface of the substrate during feeeding of SiH_2Cl_2. However, the number of Si atoms taken into the substrate surface was dependent on the amount of precursor SiCl_2 reduced by the H_2. As a result of the effective suppression of SiCl_2 reduction by the "H_2 intermittent flow" method during feeding of SiH_2Cl_2, it was possible to obtain a constant 3C-SiC growth rate independent of the flow rate of source gases, flow time, and growth temperature. The 3C-SiC film formed on the Si substrate through the alternate supply of source gases was found to consist of anti-phase domains (APDs) and twin planes. The mutual coalescence of APDs during the SiC growth process brought about a reduction in their densities.
