Polytype homogeneity and doping distribution in homoepitaxial 4H SiC grown on nonplanar substrates

SiC was grown around stripe mesas, oriented along the <11 (2) over bar0> and <1 (1) over bar 00> lattice directions on 4H SiC substrates. The grown layers were investigated with respect to polytype homogeneity by using cathodoluminescence. It was found that 3C inclusions rarely occur at normal growth conditions. However, 3C inclusions were prevalent at low growth temperatures and high C:Si ratios at the mesa tops, where the (0001) plane is revealed during growth. The doping distribution was recorded on cleaved mesa cross sections by using scanning capacitance spectroscopy. It was found that the p-type doping (using Al as the dopant) was considerably lower at the mesa walls than on the mesa tops or between the mesas, while the n-type doping (using N as the dopant) was independent of the substrate geometry. (C) 2002 American Institute of Physics.