PHOTOASSISTED DRY-ETCHING OF GAN

Photoassisted etching of GaN in HCl by a 193 nm ArF excimer laser is r eported, A directed stream of HCl etchant with background pressure of similar to 5 X 10(-4) Torr, sample temperature between 200 and 400 deg rees C and 1400 mJ/cm(2) laser fluence combined to produce etching. Sm ooth etch features and distinct sidewalls were observed, For the HCl/G aN system, photoassisted etching occurred only when both HCl and laser energy were present. (C) 1996 American Institute of Physics.