Reactive ion etching damage in n-GaN and its recovery by post-etch treatment

Reactive ion etching (RIE) in unintentionally doped GaN and damage recovery by post-etch treatment (rapid thermal annealing followed by KOH treatment) were investigated. Induced surface damage by RIE etching degraded the rectifying I-V behaviour and increased the interface state density. Post-etch treatment on the RIE etched sample improved the rectifying characteristics and reduced the interface state density. Although the electrical properties did not restore to those of the as-grown sample, post-etch treatment is effective in removing surface damage by RIE etching in n-GaN.