Cleaning of GaAs surfaces with low-damage effects using ion-beam milling

A low-damage ion-beam cleaning technique for GaAs surfaces is presented. The technique is utilized on GaAs/GaAlAs diode lasers, using the cleaved mirrors to analyze the milling performance. We found that (which also has been indicated by another author) nitrogen ions give no or very little surface damage. Contrarily, the commonly used argon ions are shown to create mirror surface damage detrimental to the laser diode performance. Auger depth profile of the GaAs oxygen contaminants reveals that 100-Å etch depth is sufficient to remove the native surface oxide. This etch depth is within the limits studied in this investigation.