Formation of denuded zone and bulk micro-defects in floating zone silicon

A denuded zone and bulk micro-defects are described in the floating zone silicon grown in hydrogen ambience and irradiated with neutrons. The formation of micro-defects is associated with the damage of neutron transmutation doping, the catalyzing of hydrogen and the conditions of annealing. The first-step annealing temperature has big influence on the size of the defects. The higher temperature of the first-step annealing, the bigger the size of the defects. During annealing the defects have a course of growing, which become the biggest size after annealing at 1100°C for 2 h. The quality of the silicon wafer has big influence on the formation of denuded zone which always lies in non-polished side and the denuded zone has not been found on the surface in the both-side polished silicon wafer after the annealing.