RADIATION DAMAGE IN SEMICONDUCTORS.

Abstract

The effect of radiation-induced point defects on impurity diffusion in silicon is investigated using proton and electron irradiation. The active defects have a diffusion length near 3 microns in pulled silicon, and dislocations are found to act as defect sinks, but are not dominant for dislocations densities less than 10 to the 7th power/sq cm. Defect precipitation is shown to occur at high defect concentrations, leading to enhanced annealing of point defects and formation of stress centers stable against annealing to 1000C. A model is proposed by which impurities diffuse by a vacancy mechanism and vacancy diffusion is limited by complex formation with oxygen atoms. (Author)