Defect engineering in MBE grown GaAs based materials

Complete control of the native point defect concentration in GaAs grown by MBE at low temperatures (LT-GaAs) can be achieved by the introduction of Be acceptors. Near intrinsic electrical resistivity, ultrahigh breakdown fields, and simultaneously ultrashort carrier lifetimes were obtained. Generally, Be-doping is found to be beneficial for the thermal stability of the epilayers. Maximal stability is reached using Be doping levels similar to the As antisite defect concentration (balanced doping). Additionally, the increased thermal stability of Be-doped LT-GaAs can be utilized to introduce and stabilize ultrahigh Be-doping concentrations which results in p-conductive epilayers with record hole concentrations approaching 4/spl times/10/sup 20//cm/sup 3/. The present work is focused on exploring possible reasons for the thermal stabilization and the increase in maximum Be incorporation.