III-nitride grating grown on freestanding HfO 2 gratings

Abstract

We report here the epitaxial growth of III-nitride material on freestanding HfO 2 gratings by molecular beam epitaxy. Freestanding HfO 2 gratings are fabricated by combining film evaporation, electron beam lithography, and fast atom beam etching of an HfO 2 film by a front-side silicon process. The 60-μm long HfO 2 grating beam can sustain the stress change during the epitaxial growth of a III-nitride material. Grating structures locally change the growth condition and vary indium composition in the InGaN/GaN quantum wells and thus, the photoluminescence spectra of epitaxial III-nitride grating are tuned. Guided mode resonances are experimentally demonstrated in fabricated III-nitride gratings, opening the possibility to achieve the interaction between the excited light and the grating structure through guided mode resonance. © 2011 Wang et al.