Selective Area Epitaxy of GaN Nanostructures: MBE Growth and Morphological Analysis

Abstract

This work presents the selective area epitaxy of GaN nanostructures grown on Ga-polar GaN/sapphire substrates by plasma-assisted molecular beam epitaxy. We demonstrate three types of nanostructures, including nanowires, nanofins, and nanorings on GaN-on-sapphire templates as well as investigate the ways of controlling their morphology, and orientation of sidewall plus top facets. A range of growth conditions including low to high Ga flux were employed during selective area epitaxy to develop these nanostructures with homogenous geometry and near vertical and smooth sidewalls. Using appropriate growth conditions and mask patterning orientations, nonpolar nanofin grids containing both/either m-/a-planes with as low as 260 nm fin width and up to six interconnects are demonstrated with smooth sidewalls. Based on these experimental results, we developed a growth model that takes different sidewall facets and orientations into account. The model generalizes the experimental results well and explains the growth conditions for the nanostructures. This study serves to advance the understanding of selective area epitaxy for defining complex III-nitride nanostructures that constitute an active area of research and development in the fields of nanotechnology and nanoscience.

A Review on Gallium Nitride for Liquid Sensors: Fabrications to Applications

“…Moreover, certain fabrication methods may entail high temperatures, constraining substrate options, and introducing challenges in controlling the growth process. Additionally, achieving uniformity in the size, shape, and orientation of GaN nanostructures across a large area can be challenging, leading to variations in device performance. − Addressing these challenges requires careful optimization of growth conditions, development of novel fabrication techniques, and advancements in material characterization methods. The following section provides detailed insights into our experimental findings.…”

Unveiling the mechanism of remote epitaxy of crystalline semiconductors on 2D materials-coated substrates

“…SAE has been considered as localized epitaxy of thin films at desired locations. Recent progress in nanomaterials growth has demonstrated that SAE can be useful to control morphology and sizes of nanostructures [ 77 , 78 ]. Studies of SAE have brought fruitful discussions on chemical/physical patterning of surfaces of substrates to deliver contrast of adsorption and desorption of precursor molecules and adatoms rather than a growth mechanism.…”