REACTIVE ION ETCHING OF INAS, INSB, AND GASB IN CCL2F2/O2 AND C2H6/H2

Reactive ion etching (RIE) of InAs, InSb, and GaSb in either CCl2F2/O2 or C2H6/H2 discharges has been examined as a function of gas composition, flow rate, pressure, power, and etching time. The C2H6/H2 chemistry gives smooth, controlled etching of these materials for C2H6 concentrations less than 40% by volume in H2, and the etch rates are in the range 280-350A under these conditions. Subsurface lattice disorder was restricted to ≤50Å in depth for both types of etching. The CCl2F2/O2 chemistry led to consistently rougher surface morphologies on all three materials with In droplets visible on InAs. The etch rates with CCl2F2/O2 are higher by factors of 2–5 than for C2H6/H2, and the etched surfaces all show significant concentrations of Cl-containing residues. © 1990, The Electrochemical Society, Inc. All rights reserved.