Electrical characterization of as-grown and thermally treated 8 inches silicon wafers

Minority and majority carrier properties of as grown and rapid thermally annealed 8″ Si wafers were investigated. Surface and bulk recombination mechanisms were monitored by measuring surface recombination velocity and minority carrier diffusion length, while the defective state of the material was analyzed by measuring extended defect electrical activity, trap concentration and activation energy. A significant deactivation of the shallow acceptors in the sub-surface region was observed in as-grown wafers and attributed to hydrogen introduced in Si during the chemo-mechanical polishing, while an increase in the defective content of the starting material and, correspondingly, an evident reduction of the diffusion length and an increase in the surface recombination rate were detected in thermally treated wafers.