Hydride vapor phase epitaxy of strain-reduced GaN film on nano-island template produced using self-assembled CsCl nanospheres

Thick GaN films were overgrown by HVPE on nano-island templates, which was fabricated by inductively coupled plasma etching using self-assembled CsCl islands as etch masks. The truncated cone-shape nano-islands exhibited significant effects on improvement of crystalline quality and reduction of crack density for subsequent GaN growth. Photoluminescence and micro-Raman measurements showed improved optical properties and partial strain relaxation in the overgrown GaN when compared to that grown on as-grown template, originated from the initial selective growth. Compared to conventional epitaxial lateral overgrown GaN, the economic and rapid method would put forward new promising pathway to fabricate high quality GaN. ► Self-assembled CsCl nanoislands are used to obtain GaN nano-island arrays by ICP. ► Nano-island template may improve crystalline quality and release stress via NELO. ► The economic and rapid method presents new pathway to fabricate high quality GaN.