Deactivation of arsenic as an acceptor by ion implantation and reactivation by low-temperature anneal

Arsenic incorporated in HgCdTe epifilms at levels ranging from 6×10¹⁴ to 4×10¹⁶ cm⁻³, and activated completely as an acceptor, converts into a donor upon introduction of specific damage introduced by ion milling, ion implantation, or ECR. The results could be correlated to the formation of a complex between the arsenic and a product of the lattice damage process. If this product is assumed to be an atom, which could be an Hg interstitial, then a direct mass balance relationship dictates the formation of one Hg interstitial for each 49,000 atoms of Hg removed by the damage process. A very similar relationship is observed in the annihilation of metal vacancies pre-existing in the solid by damage introduced by ion milling. The deactivated arsenic, present as a donor, can be restored back to complete activation as an acceptor upon annealing for relatively short durations at 120°C.