ELECTRICAL DEACTIVATION OF ARSENIC AS A SOURCE OF POINT-DEFECTS

The effect of electrical deactivation of arsenic in silicon has been s tudied. High concentrations of arsenic were implanted and laser melt a nnealed, creating boxlike fully electrically active arsenic layers, wi th no residual implant damage. Wafers were then subjected to low tempe rature thermal cycles while a buried boron layer monitored point defec ts. Strong enhancements in the boron diffusion were observed suggestin g that arsenic deactivation releases large numbers of interstitials. T his is explained by a process where the vacancies required by the deac tivated arsenic structures are created through a deactivation assisted Frenkel pair generation process, thus injecting interstitials.