Heteroepitaxial 3C-SiC on Si with various carbonization process conditions

The surface morphology and crystallinity of cubic silicon carbide (3C-SiC) films are the most important factors to affect performance of 3C-SiC-based electronic devices. This article presents the effect of carbonization condition, such as the process temperature and the source gas flow rate, on the surface roughness and crystalline quality of heteroepitaxial 3C-SiC films grown on Si(001) substrates. Morphological analysis using scanning electron microscopy (SEM), optical microscopy, and atomic force microscopy (AFM) reveals that decreasing the carbon-based precursor gas-on temperature from 1100°C to 700°C after in situ cleaning significantly improves the surface morphology of subsequent 3C-SiC films. Also, decreasing the carbonization temperature from 1250°C to 1150°C reduces the protrusion defect density from >400/mm ² to <30/mm ². Comparison of crystalline quality of 3C-SiC with two different propane gas flow rates of 3 sccm and 15 sccm during carbonization, using x-ray diffractometry and scanning probe microscopy, indicates little influence on crystalline quality as flow rate changes.