Long range Coulomb effects on hydrogen debonding from boron acceptors in silicon.

摘要

Previous work has demonstrated that B(center dot)H pairs in silicon thermally dissociate obeying simple first order kinetics if they are located in a region depleted of majority carriers. B(center dot)H debonding in equilibrium, however, is a slower, more complex process. We have investigated the dissociation of B(center dot) pairs under a variety of equilibrium and non-equilibrium conditions and have demonstrated that the dissociation process is strongly influenced by the local concentration of majority and minority carriers. In particular, we show that injection of minority carriers can markedly accelerate the dissociation process. A model is proposed which suggests that hydrogen released from an acceptor, while initially positive, must always be neutralized before escape is possible. This picture correctly describes the time dependence of debonding in equilibrium, and it predicts the enhanced debonding in forward biassed diodes provided the characteristic time for H charge conversion is long. 25 refs., 3 figs.