Rapid, Laser-Induced Etching of GaAs in an HF Solution.

Rapid, room-temperature photochemical aqueous etching of n- type GaAs is achieved in an HF-acid-based solution. Etch rates of ~600microns/min under UV laser illumination represent more than an order of magnitude increase over previously reported results for solutions containing no HF acid. This rapid process is used to etch deep, large-area structures such as trench formations and through-wafer via holes.