Experimental exploration of the fabrication of GaN microdome arrays based on a self-assembled approach

The formation of large scale, highly uniform and controllable GaN microdome arrays based on a self-assembled low cost method was investigated. The deposition of a large area, hexagonally close-packed SiO2 microsphere monolayer on top of the III-nitride semiconductor using the dip-coating method was optimized, which leads to surface coverage of 87% of SiO2 on GaN (ideal close-packed microsphere surface coverage is 90.7%). Reactive ion etching was used to simultaneously etch both SiO2 microspheres and GaN substrate to form GaN microdomes. Experiments show that GaN microdomes with controllable size, shape, and aspect ratio are achievable through controlling the plasma etching conditions.