Application of CCl2F2- and CCl4-based plasmas for RIE of GaSb and related materials

We report on the RIE etching of GaSb, AlGaAsSb and InGaAsSb materials in CC l2F2 and CCl4 plasmas diluted with either H-2 or N-2. The highest etch rate (similar to 2 mu m/min for GaSb) was achieved with CCl4/N-2 chemistry, how ever, with an important degree of selectivity in etching of GaSb and quater nary alloys. By contrast, CCl4/H-2 plasma enables anisotropic etching of he terostructure materials at an etch rate of similar to 0.2 mu m/min. CCl2F2- based plasma exhibited very slow etch rates (less than or equal to 100 nm/m in) and high selectivity in etching of GaSb over AlGaAsSb. The obtained res ults were applied in patterning of micrometer-size circular and stripe mesa s in photonic GaSb/lnGaAsSb/AlGaAsSb device structures, as well as in the f abrication of submicron circular gratings in GaSb. (C) 2000 Elsevier Scienc e Ltd. All rights reserved.