Chlorine (Cl2) reactive ion beam etching (RIBE)‐induced damage on the GaAs wafer has been characterized by studing the characteristics of Schottky diodes fabricated on the etched surfaces. The ideality factors and the Schottky barrier heights measured by the current–voltage characteristics for ion extraction voltage range from 30 to 200 V at Cl2gas pressure of 2×10−3Torr and are comparable to those of the reference sample cleaned by HCl. Both thenvalue and the barrier height degrade for ion extraction voltage of more than 300 V. For higher Cl2gas pressure, the damage on the etched surface is less. These results suggest that with the low‐energy ions and high‐Cl2gas pressure, the damage of the GaAs surface is reduced significantly. The electron deep levels induced by RIBE disappear after annealing at 400 °C for 10 min.