EFFECTS OF HYDROGEN ON THE ANNEALING BEHAVIOR OF NEUTRON-RADIATION-INDUCED DEFECTS IN SI

Positron-lifetime measurements indicate that the effect of hydrogen on the annealing behavior of defects in Si irradiated with 3.6X10(17) ne utrons/CM2 is very obvious. Neutron-induced monovacancy-type defects i n hydrogen-containing Si disappear at 400-degrees-C, 200-degrees-C low er than in neutron-irradiated Si without hydrogen because of hydrogen passivation and the formation of hydrogen-defect shallow donors; an an nealing valley at 150-degrees-C is mainly due to the annealing out of V-H pairs and passivation of acceptor centers by hydrogen. Hydrogen pr omotes annealing out of V2-type defects above 400-degrees-C. The reapp earance of V-type defects in neutron-irradiated Si with and without hy drogen at 600-degrees-C is proposed to be due to a completely differen t mechanism.