AlN nanostructures and flat, void-less AlN templates formed by hydride vapor phase epitaxy on patterned sapphire substrates

Abstract

Severe growth irregularity usually encountered in AlN growth on patterned sapphire substrates (PSSs) was completely suppressed in hydride vapor phase epitaxial (HVPE) growth on a PSS having small cone-pattern with a height of 220 nm. At low temperature, the AlN growth on the PSS led to a formation of regular array of hexagonal AlN nano-rods on the cone-Tops. At high temperatures, the growth mode turned into a layered fashion and a void-less AlN template with an atomically smooth surface and high crystal quality were realized with an HVPE growth thickness less than 1 μm.