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 mm~2 at different tem-peratures 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 × 10μm~2. The homoepitaxial layer was oh-tained 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.

the National Basic Research Program of China,the National Natural Science Foundation of China