A 100 nm thick InGaN/GaN multiple quantum-well column-crystallized thin film deposited on Si(111) substrate and its micromachining.

A 100 nm thick InGaN/GaN multiple quantum-well column-crystallized thin film was deposited on Si(111) substrate, with InN as the interlayer, by molecular beam epitaxy. The diameter of the column crystal is about 40 nm. Transmission electron microscopy images showed clear five-period well layers. Photoluminescence measurements demonstrated a wide emission wavelength from about 500 to 800 nm with the full width at half maximum of 107 nm at room temperature. An unusual photoluminescence peak position shift was observed from the optical measurement. The selected area electron diffraction image demonstrated the hexagonal wurtzite structure of the column crystal. A self-supported GaN-based active subwavelength grating was proposed, and the active subwavelength grating structure was fabricated from the InGaN/GaN quantum-well thin film by a Si micromachining process.