Inductively coupled plasma etching of III–V semiconductors in BCl -based chemistries 3 I. GaAs, GaN, GaP, GaSb and AlGaAs

BCl3, with addition of N2, Ar or H2, 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 for these materials are observed at 33% N2or 87% H2 by flow.addition to BCl3, whereas Ar addition does not show this behavior. Maximum etch rates are typically much higher for GaAs, GaP, GaSb and AlGaAs ;1.2 mmrmin.than for GaN ;0.3 mmrmin. due to the higher bond energies of the latter. The rates decrease at higher pressure, saturate with source power ion flux.and tend to show maxima with chuck power ion energy.. The etched surfaces remain stoichiometric over a broad range of plasma conditions. q1999 Elsevier Science B.V. All rights reserved.