inas/gaas heteroepitaxy: real-time reflectance-anisotropy spectroscopy

Abstract

Reflectance Difference Spectroscopy (RDS) is an in-situ and in real-time measurement technique used to study optical anisotropies during InAs/GaAs(001) growth. Studies were performed in a Molecular Beam Epitaxy (MBE) ultra-high vaccum chamber under different As overpressures and several substrate temperatures. Reflectance Difference Spectroscopy was used to acquire the experimental data, which were measured with an acquisition time of 100 ms. As a mathematical tool, Singular Value Decomposition (SVD) was used to analyse the measured spectra in order to obtain representative bases Si(E) which with a linear combination of them, each of the spectra (S(E,t)) is reproduced. S(E,t)= Pi 1 ci(t)Si(E) is the mathematical representation of the fittings for each experimental measured data. Physical Models such as Strain are used to fit the obtained representative bases.