ANGLE ETCH CONTROL FOR SILICON-CARBIDE POWER DEVICES

Silicon carbide plasma etching results are reported. Etching experimen ts are performed in a distributed electron cyclotron resonance reactor , using a SF6/O-2 gas mixture, on both 3C- and 6H-SiC. A special inter est has been given to the slope of the etched sidewalls. Slopes betwee n 30 degrees and 80 degrees have been achieved by varying selectivitie s between SiC and the SiO2 masking layer. Two parameters have been inv estigated to modulate selectivity: bias voltage and O-2 additive flow. A wide range of selectivities (from 1 to 6.5) has been obtained for s uitable etch rate (100 to 270 nm/min) with very smooth surfaces. (C) 1 996 American Institute of Physics.