N Takada, N Taoka, T Yamamoto, A Ohta, NX Truyen… – Japanese Journal of …, 2019
Abstract
The impact of oxidation of a GaN surface changing the oxidation temperatures and the oxidation time using remote oxygen plasma on photoluminescence (PL) properties are investigated with a well-controlled photon flux for the excitation. The PL intensities related to transition at the band edges obviously decreased after the oxidation. From the detailed spectra analysis of PL combining the results obtained by photoelectron yield spectroscopy and X-ray photoelectron spectroscopy, we found that oxygen doping in GaN occurs during plasma oxidation, resulting in PL intensity reduction. These results suggest that, to precisely control the dopant concentration, attention should be paid to the oxidation process in the GaN device fabrication process.
… PL emission was collected using a collimator lens and an optical fiber through a long-pass filter to remove scattering light of the laser beam, which was detected using a spectroscope (Stellar Net Inc., BLACK-Comet) …
