Reactive Ion-Beam Etching of InP with Cl₂

Reactive ion-beam etching (RIBE) of InP with Cl 2 at room temperature has been studied by varying the ion extraction voltage and the gas pressure. The sputtering yield is found to increase linearly with the ion extraction voltage above a threshold voltage. RIBE with a higher Cl 2 gas pressure is dominated by the chemically reactive etching, and offers a higher etch rate and a smoother surface. Smooth surfaces with low concentrations of residual Cl atoms are obtained under the ion extraction voltage of 400 V and Cl 2 gas pressure of 2.5×10 -3 Torr.