Process Of4H-SiC Thick Epitaxial Layer

Research of SiC high voltage and power devices is being interesting rencent years.To produce SiC power devices such as5kV diodes and MOSFETs needs thick SiCepitaxial layer with high quality, while the rencent epitaxial growth rate of5μm/h cannotmeet the requirements of growth time. This paper studies the4H-SiC thick homogeneousepitaxial layer process. The influence of growth rate, thickness uniformity and crystalquality on growth time, source flow rate, growth temperature, growth pressure andcarrier gas flow rate was studied by changing these growth conditions.In this paper, the homogeneous epitaxial growth was performed on n-type4°off-axis4H-SiC (0001) Si face in a horizontal hot-wall low pressure CVD reactor underdifferent growth conditions and throughout FTIR thickness testing and X-ray diffractionanalysis, some important conclusions are obtained. Under the same conditions,thehighest growth rate13.0μm/h can be obtained at SiH4flow of50ml/min in hydrogenflow70L/min; High crystal quality with XRD FWHM of16.3053and thicknessuniformity of0.32%can be obtained at SiH4flow rate of39ml/min, at the same timethe growth rate is9.4771μm/h; Higher crystal quality can be obtained under lowerpressure.Through the analysis of conclusion, High crystal quality will be possibly grownunder lower growth pressure of50mbar at high growth rate.