Characterization and Comparison of 4H-SiC(1120) and 4H-SiC(0001) 8° Off-Axis Substrates and Homoepitaxial Films

Abstract

AbstractHomoepitaxial films of 4H-SiC(1120) and 8° off-axis 4H-SiC(0001) have been grown and characterized. The number of domains and the range of full-width half-maxima values of the x-ray rocking curves of the [1120]-oriented wafers were smaller than the analogous values acquired from the (0001) materials. Hydrogen etching of the former surface for 5 and 30 minutes reduced the RMS roughness from 0.52 nm to 0.48 nm and to 0.28 nm, respectively; the RMS roughness for a 30 μm (1120) film was 0.52 nm. Micropipes in the substrates did not thread beyond the film-substrate interface. The separation distance between stacking faults was determined to be 10 μm by transmission electron microscopy. Hall mobilities and carrier concentrations of 12,200 cm2/Vs and 3.1×1014 cm−3 and 800 cm2/Vs and 7.4×1014 cm−3 were measured at 100°K and 300°K, respectively. Photoluminescence indicated high purity. 4H-SiC(1120) PiN devices exhibited average blocking voltages to 1344 V and a minimum average forward voltage drop of 3.94 V.