The role of the impurity atmosphere of dislocations during radiation defect accumulation in silicon

Abstract

The accumulation processes of the compensating and recombination centres during G°Co yray irradiation of n-type Si (p=50-250 Rcm, s=50-100 ps) with a high dislocation density ( N D = 1.104-1' lo7 cm-2) introduced by plastic deformation are studied. The results are obtained from measurements of the minority charge-carrier lifetime by the method of conductivity modulation at a point contact and the Hall coefficient temperature dependences. Radiation defect introduction efficiency is found to depend significantly on the content of the dislocation impurity atomosphere whose change is achieved by varying the deformation conditions (fast and slow cooling) and subsequent radiation-heat treatments (y-ray irradiation and annealing). The experimental results are interpreted taking into account the conception of compensation of elastic stress fields by impurity atoms and participation of impurities in complexing with primary radiation defects near dislocations.