Study of surface defects on 3C-SiC films grown on Si(111) by CVD

摘要

Monocrystalline 3C-SiC layers were synthesized by atmospheric pressure chemical vapor deposition on Si(111) substrates using SiH_4 and C_3H_8 gases at temperatures between 1350℃ and 1400℃. Both atomic force microscopy and X-ray diffraction spectroscopy measurements reveal a notable dependence of surface morphology and layer quality on the C/Si ratio in the gas phase during experiment. In particular, three types of surface morphologies have been observed: (ⅰ) rough, (ⅱ) mirror-like and (ⅲ) pyramidal defect covered, attributed to lack of C, C limited growth and stacking faults generation, respectively. From Raman spectral peak shifts, a tensile strain state of the SiC films, lower for the 1400℃ grown series, was found.