Low energy electron‐enhanced etching of GaAs(100) in a chlorine/hydrogen dc plasma

Low energy electron‐enhanced etching of GaAs(100) has been achieved by placing the sample on the anode of a low‐pressure hydrogen/chlorine dc discharge. Samples etched at room temperature reveal good anisotropy (≳20), good selectivity (≳200 against SiO2 masks at room temperature), and smooth surfaces at etch rates of 250 A/min; etch rates up to 4.5 μm/min were achieved at 150 °C. The dependence of the etch characteristics on gas composition, pressure, and temperature is described.