We report highly resolved, damage-free etching of GaAs and related materials. The etching is activated by excimer laser irradiation at 193 nm of samples maintained at low temperatures (∼140 K) in a chlorine atmosphere (∼5 mTorr). Since the etching is chemical in nature, structural damage to the substrate should not be present. Submicrometer resolution has been achieved by the use of electron beam lithography to pattern a Si3N4 contact mask. We have also successfully used our etching in the fabrication of a single-quantum-well, ridge-waveguide semiconductor laser.