4H–SiC homoepitaxy on nearly on-axis substrates using TFS-towards high quality epitaxial growth

Abstract We report high quality homoepitaxial growth on nearly on-axis ( ± 0.5 ° ) 4H–SiC substrates by chemical vapor deposition (CVD) using Tetrafluorosilane and Propane as Si and C-precursors, respectively. N-type unintentional doping (10 17 –10 14  cm −3 ) was obtained for 0.6 R g - 5–14 μm/h, which was found to be C-controlled. At C/Si R g was weakly dependent on the ratio, with a clear transition from step-controlled growth (0.6 2.0, a linear dependence on C-flow is established, with a return to step-mediated growth, shown by the surface morphology (RMS roughness ∼1 nm), and high polytype uniformity from Raman at high R g - 14 μm/h. These two behaviors were ascribed to a decrease in the etch rate of SiC by SiF 4 with increasing C/Si due to C-aided decomposition of SiF 4 , both of which make available a greater amount of elemental Si at the surface, thereby suppressing spiral growth. Use of on-axis or near on-axis substrates can eliminate/reduce basal plane dislocations which limit the performance of SiC bipolar electronic devices.