Growth of 3C-SiC Layers on Silicon Substrates with a Novel Stress Relaxation Structure

摘要

Silicon (Si) substrates having cavities just beneath the surface layer (multi-cavity Si substrates) were examined whether they worked as the stress relaxation structure in 3C-SiC heteroepitaxial growth on Si. Single crystalline 3C-SiC layers were grown on the multi-cavity Si substrates by means of low pressure chemical vapor deposition (LPCVD). The layers' quality was characterized by the cross-sectional TEM observations and the Micro-Raman spectroscopy. The TEM results showed that this structure reduced the defect density in the 3C-SiC layers. The averaged full width at half-maximum (FWHM) of LO Raman mode in the 3C-SiC layers on the multi-cavity Si substrates became narrower than that on the conventional Si substrates. Furthermore, Schottky barrier structures showed that the reverse leakage current of the diodes using the multi-cavity Si substrates is smaller than that using the conventional Si substrates. These results indicate that the multi-cavity Si substrates are effective for stress relaxation in the 3C-SiC layers.