Reactive-ion-beam etching of InP in a chlorine–hydrogen mixture

We present the first application of Cl2+H2 reactive-ion-beam etching of InP. Specularly smooth etching is achieved using an ion beam of 53%–73% Cl2 in H2 at a 300 eV extraction potential with the substrate held at 250 °C. InP etch morphology and rate are examined as functions of Cl2+H2 mixture, sample temperature, and chamber pressure. Significant deviation from the optimum smooth-etch conditions are seen to result in rough surfaces.