Open AccessFabrication and characterization of freestanding circular GaN gratings
Author(s) -
Yongjin Wang,
Fangren Hu,
H. Sameshima,
Kazuhiro Hane
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.000773
Subject(s) - materials science , deep reactive ion etching , gallium nitride , optoelectronics , etching (microfabrication) , silicon , grating , nanostructure , nanopillar , fabrication , substrate (aquarium) , surface micromachining , optics , reactive ion etching , focused ion beam , silicon nitride , nanotechnology , layer (electronics) , ion , medicine , oceanography , alternative medicine , physics , pathology , geology , quantum mechanics
It's of significant interest to combine freestanding nanostructure with active gallium nitride (GaN) material for surface-emitting optoelectronic application. By utilizing bulk micromachining of silicon, we demonstrate here a promising way to fabricate freestanding GaN nanostructures using a GaN-on-silicon system. The well-defined nanoscale circular GaN gratings are realized by fast-atom beam (FAB) etching, and the freestanding GaN gratings are obtained by removing silicon substrate using deep reactive ion etching (DRIE). The freestanding GaN slab is thinned from the backside by FAB etching to reduce the confined modes inside the GaN slab. The measured microphotoluminescence (micro-PL) spectra experimentally demonstrate significant enhancements in peak intensity and integrated intensity by introducing freestanding circular grating. This work represents an important step in combining GaN-based active material with freestanding nanostructures for further increasing light-extraction efficiency.