Minimum Al0.5Ga0.5As-GaAs heterojunction width determined by sputter-Auger techniques

Two intimately connected parameters are investigated: the abruptness of MBE heterojunctions and the minimum depth resolution of the sputter-Auger technique. Using 250-eV Ar+ ions and monitoring the Al LVV Auger transition, the sharpest interface measured to date (13–15 Å) is obtained. After correcting for the electron escape depth, a minimum interface width of 9 Å is obtained. Large increases in interface broadening with increasing Ar+ ion energies are observed.