Encapsulation of ion-implanted GaAs using native oxides

It was found that oxidation at 500 to 600°C produced uniform layers, which, when used as protective coatings for ion-implanted GaAs, gave rise to donor activity, but with poor reproducibility. The addition of a thin layer of evaporated aluminium to the oxide layer gave donor activities very similar to results obtained with other coating materials and with good reproducibility.