Reorientation of the B-H complex in Si: Non-arrhenius kinetics and a reverse isotope effect

Abstract

The B-H complex in Si can be aligned by stress and reorients with an activation energy of roughly 0.2 eV. When the complex reorients, the H atom jumps from one bond-centered site adjacent to the B atom to another. We show that the reorientation kinetics deviate from Arrhenius behavior for small jump rates (≈10 −6 s −1). This result supports a previous suggestion that the H jumps by a thermally assisted tunneling mechanism. Further, we show that the reorientation rate for B-D is greater than that of B-H for T > 57K.