An epitaxial, laterally-overgrown (ELOG) GaN layer is deposited on a Si(111) substrate using high-dose, N þ ion implantation.ELOG GaN is deposited on a Si(111) wafer with implantation stripes by metal-organic (MO) CVD. The GaN layer on the N þ ion-implanted region is polycrystalline and acts as a mask for the ELOG process. This is attributed to the growth rate of the polycrystalline GaN being much slower than that of epitaxial GaN. After 120 min, complete coalescence is achieved with a flat surface. Scanning cathodoluminescence (CL) microscopy and high resolution X-ray diffraction (HRXRD) confirm the high optical and crystalline quality of the ELOG GaN layer.

Epitaxial lateral overgrowth (ELO) process has limited use in GaN devices due to the uneasiness of regrowth or the likeliness of contamination from the ELO mask, even though it is a method to reduce the dislocation density in GaN grown on sapphire substrate. Here we introduce a maskless and single-step ELO process using a high-dose N+-ion implantation. We employed a high-dose N+-ion implantation as an ELO mask instead of usual dielectric material such as SixNy or SiO2. The GaN layer was laterally grown over the ion implanted array formed in a stripe pattern of 4-µm-width, resulting in a complete coalescence after 30 min. TEM and photoluminescence analysis confirmed the reduced dislocation density of the ELO grown GaN layer.