STUDY ON HIGH-SPEED DEEP-ETCHING OF GAN FILM BY UV LASER-ABLATION

High-speed deep etching of GaN thin films by UV (266 nm) laser ablatio n followed by a treatment in HCl solution, was achieved. The etch rate was as high as 50 nm/pulse. Scanning electron microscopy and scanning probe microscopy measurement results indicate that the surface of the etched films was structurally well-defined and cleanly patterned. Mic ro-photoluminescence measurements of ablated samples revealed no sever e damage to the optical properties or the crystal structure. In additi on, coupling with VUV (133-184 nm) laser beams, the etch quality of Ga N was markedly improved. The etch rate was 55 nm/pulse (C) 1998 Elsevi er Science B.V. All rights reserved.