Interstitial hydrogen and neutralization of shallow-donor impurities in single-crystal silicon

Abstract

It is demonstrated for the first time that hydrogen can passivate shallow-donor impurities in n-type single-crystal silicon, and a novel chemical-bonding model is proposed to explain the phenomenon. Phosphorus greatly slows the bulk diffusion of hydrogen at \ensuremath{\sim}150 \ifmmode^\circ\else\textdegree\fi{}C. Conductivity and Hall measurements show that the room-temperature electron density is decreased by hydrogenation, but the mobility is increased, so that compensation is ruled out. Total-energy calculations predict an energy minimum for H at the antibonding site of a silicon nearest neighbor of substitutional P. Known solubilities imply \ensuremath{\sim}1-eV binding for atomic H in pure silicon.