III-Nitride grating grown on freestanding HfO(2 )gratings

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. PACS: 78.55.Cr; 81.65.Cf; 81.15.Hi.