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 CC12F2/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 260-350 angstrom under these conditions. Subsurface lattice disorder was restricted to ≤50 angstrom in depth for both types of etching. The CC12F2/O2 chemistry led to consistently rougher surface morphologies on all three materials with In droplets visible on InAs. The etch rates with CC12F2/O2 are higher by factors of 2-5 then for C2H6/H2, and the etched surfaces all show significant concentrations of C1-containing residues