Effects of C/Si ratio in chemical vapor deposition of 4H-SiC(11(2)over-bar0) and (03(3)over-bar8)

Homoepitaxial growth of 4H-SiC(1120) and (0338) by hot-wall chemical vapor deposition has been investigated. Both the residual-donor concentration and deep-level concentrations can be reduced by increasing the C/Si ratio during growth. The optimum C/Si ratio for obtaining high-quality epilayers with good morphology is higher on the non-basal planes than,on off-axis (0001). The correlation between deep levels and growth condition is discussed.