In this paper, we report the reactive ion etching (RIE) of trenches in
GH-silicon carbide using SF/O-6(2). The plasma parameters: etchant co
mposition, gas-flow rate, chamber pressure, and radio frequency power
were optimized to obtain a maximum etch rate of 360 Angstrom min. The
etch rate of SiC was found to exhibit a direct correlation with the dc
selfbias except when the O-2 percentage was varied. Trenches were fab
ricated using the optimized conditions. It was found that the trench s
urface was extremely rough due to the aluminum micromasking effect. To
overcome this effect, a Teflon(TM) sheet was used to cover the cathod
e during the experiment. The trenches fabricated using this modificati
on were found to have smooth etched surfaces and sidewalls. The angle
of anisotropy of these trenches was approximately 80 degrees which is
suitable for device applications.