DEFECT PRODUCTION AND ANNEALING IN ION-IMPLANTED AMORPHOUS-SILICON

We have elucidated the mechanisms of defect production and annealing in ion-implanted amorphous silicon using in situ conductivity measurements as a probe of the defect structure. The defect evolution is shown to depend strongly on the substrate temperature and slightly on the irradiating ion and dose rate. It is demonstrated that two different defect structures exist, one of which, never observed before, is stable at 77 K and anneals out upon heating to 300 K. These results are explained on the basis of a new model of defect evolution in amorphous silicon.