Composition Investigations of Nearly Lattice-Matched InGaPN Films on GaAs (001) Substrates Grown by MOVPE

Abstract

We have reported on an alternative way, which is a combination of micro-Raman spectroscopy and high resolution X-ray diffraction (HRXRD) measurements, to evaluate the In and N contents and a corresponding misfit strain in the InGaPN films grown on GaAs (001) substrates by metal organic vapor phase epitaxy (MOVPE). Firstly, the In content was evaluated by means of micro-Raman scattering to be 56.4±0.8 at%, 55.8±0.8 at%, 55.9±0.9 at% and 55.7±1.1 at%, which were confirmed by HRXRD, for the DMHy flow rates of 0, 300, 700 and 1,100 µmol/min, respectively. Based on HRXRD results, next, the N content was estimated to be 0.9±0.4 at%, 1.4±0.4 at% and 2.1±0.5 at% for the DMHy flow rates of 300, 700 and 1,100 µmol/min, respectively. With increasing N content, misfit strain is also reduced from 0.65% to 0.12%. This suggests that a nearly lattice-matched film, which has the highest N content of 2.1±0.5 at%, exhibits the lowest misfit strain of 0.12%. Our results showed an achievement in a use of micro-Raman spectroscopy as a tool to evaluate the In content, which is a primary parameter using to calculate the N content in the InGaPN film.