Exploring AlGaN nanostructures fabricated via chemical wet etching

AlGaN is a leading candidate for current and future ultra-wide bandgap electronic and optoelectronic applications. However, 3D etch technologies for AlGaInN remain immature compared to silicon, limiting its full potential for novel devices. Here, we build from the foundation of anisotropic KOH-based wet etchants used to fabricate GaN structures and explore AlGaN alloys etched in acids and bases. We investigate the etch reactivity of AlGaN alloys as a function of Al content in various etchants. We then explore the etch evolution of novel nanostructures observed and discuss possible mechanistic explanations. Lastly, we look at field emission properties of AlGaN alloys.