We present an optical investigation of GaN pillars using both micro-Raman (mu-Raman) and microphotoluminescence (mu-PL) spectroscopy. GaN pillars of diameter ranging from 100 nm to 5 mum were fabricated by electron beam lithography and reactive ion etching (RIE) with SiCl4 plasma. Optical measurements of both mu-Raman and mu-PL on individual pillars show consistent variations in the properties of the fabricated GaN structures as a function of GaN pillar size. mu-PL mapping gives strong evidence for defect-induced donors and/or acceptors near the facets of the RIE etched pillars. RIE for the nanostructuration of GaN could be used in the future to allow spectroscopic studies of a few or single quantum objects such as GaN quantum dots. (C) 2002 American Institute of Physics.
Niels Quack, Grigore Suruceanu, Alexandru Mereuta, Andrei Caliman, Pascal Gallo, Gergely Huszka, Mehdi Naamoun
Nicolas Grandjean, Jean-François Carlin, Raphaël Butté, Ian Michael Rousseau