Reactive ion etching induced damage in GaAs and Al_0.3Ga_0.7As using SiCl₄

The authors have investigated the etching characteristics of GaAs and Al0.3Ga0.7As using SiCl4 as the etching gas. The effect of damage caused on the etched surface has been characterized by employing Schottky diode performance, low-temperature integrated band-gap photoluminescence, Raman scattering and high-resolution X-ray photoelectron spectroscopy, and, for the first time, the usefulness of employing glancing X-ray reflectivity for the identification of surface damage is explored. Using high-resolution fabrication techniques, a novel procedure for constructing a sidewall Schottky diode has been developed to allow the amount of induced sidewall damage to be quantified. In addition, the deteriorative effect of the surface damage layer is observed to remain unchanged with etch time.