Strong influence of SiO 2 thin film on properties of GaN epilayers

Abstract

In this letter, we report strong degradation of photoluminescence (PL) performance of GaN epilayers due to SiO 2 layers that were deposited on GaN surfaces by electron-beam evaporation. Secondary ion mass spectrometry measurements show that the oxygen concentration of GaN with SiO 2 layers is one order of magnitude more than that of as-grown GaN. This fact indicates that oxygen can very easily replace nitrogen in GaN. It was also found that rapid thermal processing can recover and improve the optical quality of GaN with SiO 2 layer. As a reference, Si xN y was found to have little effect on PL performance of GaN. © 1999 American Institute of Physics.