Optical constants of GaAs from 0.73 to 6.60 eV for dielectric film thickness metrology in compound semiconductor manufacturing

This article describes the optical constants of GaAs from 0.73 to 6.60 eV determined using spectroscopic ellipsometry. Our setup includes a computer-controlled MgF₂ Berek waveplate compensator, which allows exact measurements of the ellipsometric angle Δ below the band gap. Therefore, our data are very accurate over a broad range. We apply our results to determine thicknesses and optical properties of various dielectrics (SiO₂, silicon nitride, and sputtered AlN) on GaAs