Void formation, electrical activation, and layer intermixing in Si-implanted GaAs/AlGaAs superlattices

Abstract
Direct experimental evidence is presented for the correlation between void formation, dopant electrical activation, and layer intermixing in GaAs/AlGaAs superlattices (SLs). Maximum layer intermixing is observed in the regions of maximum carrier concentration and no or little void formation in Si‐implanted and annealed SLs. In SLs implanted at room temperature, Si activation and layer intermixing enhancement are severely inhibited in the near‐surface region where voids are formed. However, when implantation is carried out at 250 °C, both the suppression of Si activation and layer intermixing enhancement in the near‐surface region are reduced, concurrent with a decrease in void density.