Inductively coupled plasma etching of III-V semiconductors in BCl3-based chemistries I. GaAs, GaN, GaP, GaSb and AlGaAs

BCl3, with addition of N-2. Ar or H-2. is found to provide smooth anisotropic pattern transfer in GaAs, GaN. GaP, GaSb and AlGaAs under Inductively Coupled Plasma (ICP) conditions. Maxima in the etch rates fur these materials are observed at 33% N-2 or 87% H-2 (by flow) addition to BCl3, whereas Ar addition does nut show tills behavior, Maximum etch rates are typically much higher for GaAs, GaP, GaSb and AlGaAs (similar to 1.2 mu m/min) than for GaN(similar to 0.3 mu m/min) due to the higher bund energies of the latter. The rates decrease at higher pressure, saturate with source Fewer (ion nux) and tend to show maxima with chuck power (ion energy). The etched surfaces remain stoichiometric over a broad range of plasma conditions. (C) 1999 Elsevier Science B.V, All rights reserved.