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 3.6\ifmmode\times\else\texttimes\fi{}${10}^{17}$ neutrons/${\mathrm{cm}}^{2}$ is very obvious. Neutron-induced monovacancy-type defects in hydrogen-containing Si disappear at 400 \ifmmode^\circ\else\textdegree\fi{}C, 200 \ifmmode^\circ\else\textdegree\fi{}C lower than in neutron-irradiated Si without hydrogen because of hydrogen passivation and the formation of hydrogen-defect shallow donors; an annealing valley at 150 \ifmmode^\circ\else\textdegree\fi{}C is mainly due to the annealing out of V-H pairs and passivation of acceptor centers by hydrogen. Hydrogen promotes annealing out of ${\mathit{V}}_{2}$-type defects above 400 \ifmmode^\circ\else\textdegree\fi{}C. The reappearance of V-type defects in neutron-irradiated Si with and without hydrogen at 600 \ifmmode^\circ\else\textdegree\fi{}C is proposed to be due to a completely different mechanism.