PLASMA-ETCHING OF III-V SEMICONDUCTORS IN BCL3 CHEMISTRIES .1. GAAS AND RELATED-COMPOUNDS

BCl3/Ar discharges provide rapid, smooth pattern transfer in GaAs, AlG aAs, GaP, and GaSb over a wide range of plasma conditions. At high BCl 3-to-Ar ratio there is significant surface roughening on GaSb, which i s correlated with the presence of B- and Cl-containing residues detect ed by Auger electron spectroscopy. BCl3/N2 discharges provide similar etch rates to BCl3/Ar, but when used with photoresist masks lead to ro ugh morphologies on the semiconductor materials due to enhanced dissoc iation and redeposition of the resist. Etch rates with electron cyclot ron resonance discharges are up to two orders of magnitude higher than for rf-only conditions.