Bias-assisted photoelectrochemical etching of p-GaN at 300 K

Photoelectrochemical (PEC) etching of p-type GaN has been realized in room temperature, 0.1 M KOH solutions. PEC etching of GaN was achieved by applyi ng a positive bias to the surface of the p-GaN layer through a deposited ti tanium mask. The applied bias reduces the field at the semiconductor surfac e, which induced the dissolution of the GaN. The effect of bias on etch rat e and morphology was examined. It was found that insulating the Ti mask fro m the KOH solution with Si3N4 significantly increases the etch rate. The rm s roughness of the etched region decreased as the bias voltage increased. E tch rates as high as 4.4 nm/min were recorded for films etched at 2 V. (C) 2000 American Institute of Physics. [S0003-6951(00)05434-6].