Electron cyclotron resonance plasma-induced damage in AlGaAs/GaAs/AlGaAs single quantum wells

Abstract
Changes in cathodoluminescence (CL) intensity from a buried single AlGaAs/GaAs/AlGaAs quantum well (QW) as a result of exposure to electron cyclotron resonance (ECR) hydrogen or argon discharges are reported. For additional dc biases of 150 V on the sample during either H2 or Ar plasma exposure, we observe substantial decreases in CL intensity from the well. Ar+ ion bombardment creates damage more resistant to annealing than does H+ ion bombardment at the same energy. The ECR discharges alone with zero additional dc bias cause degradation in the well luminescence due possibly to defects created by energetic electron bombardment or ultraviolet illumination. At intermediate bias voltages (50 V) strong hydrogen passivation of nonradiative centers is observed, leading to 500% increases in CL intensity from the well. The initial characteristics of the QW under these conditions are restored by annealing at 400 °C.