COMPARISON OF LASER-INDUCED ETCHING BEHAVIOR OF III-V-COMPOUND SEMICONDUCTORS

Laser-induced maskless etching of III-V compound semiconductors (InSb, GaAs, and InP) in a KOH aqueous solution by irradiation with a focuse d argon-ion laser has been investigated to obtain high etching rates a nd aspect ratios of etched grooves. The etching rate at low laser powe r was found to depend on the carrier density of the sample and its typ e. With the increase of the laser power, the etching reaction becomes primarily a thermochemical reaction. High etching rates and aspect rat ios have been achieved with a single scan of the laser beam. The damag e induced by laser wet etching is less than that by laser dry etching, and the damage at the etched side wall is less than that at the etche d bottom. Grooves with locally controlled depth and slab structures ha ve been fabricated for application.