Epitaxial growth on 4H-SiC by TCS as a silicon precursor

Epitaxial growth on n-type 4H-SiC 8°off-oriented substrates with a size of 10×10 mm2 at different temperatures with various gas flow rates has been performed in a horizontal hot wall CVD reactor,using trichlorosilane(TCS)as a silicon precursor source together with ethylene as a carbon precursor source.The growth rate reached 23 μm/h and the optimal epilayer was obtained at 1600℃ with a TCS flow rate of 12 sccm in C/Si of 0.42,which has a good surface morphology with a low RMS of 0.64 nm in an area of 10×10μm2.The homoepitaxial layer was obtained at 1500℃ with low growth rate(<5μm/h)and the 3C-SiC epilayers were obtained at 1650℃ with a growth rate of 60-70μm/h.It is estimated that the structural properties of the epilayers have a relationship with the growth temperature and growth rate.Silicon droplets with different sizes are observed on the surface of the homoepitaxial layer in a low C/Si ratio of 0.32.