In-situ spectral reflectance investigation of hetero-epitaxially grown β-Ga2O3 thin films on c-plane Al2O3 via MOVPE process

Abstract

Metalorganic vapor-phase epitaxy of β-Ga2O3/c-plane Al2O3 heterostructures was monitored in-situ by spectral reflectance in different wavelengths. The reflectance spectrum was analysed as a function of the growth time and the incident wavelength to estimate the growth rate and the refractive index at the growth temperatures. The obtained values are validated by ex-situ methods such as secondary ion mass spectrum measurement and spectroscopic ellipsometry. A theoretical simulation of the reflectance spectrum was carried out by combining a transfer matrix method with a multilayer model, and a good agreement with the experimental results is presented.