Trivalent behavior of palladium in silicon

Abstract

Palladium is known to exhibit an acceptor state at EC−0.22 eV in n-type Si and a donor state at EV+0.31 eV in p-type Si. We have identified a third level at EV+(0.140±0.005) eV and attribute it to the double donor state of substitutional Pd. The Pd level positions are very similar to the corresponding levels for Pt. The double donor states of both metals show an electric field dependence of the emission rates and a thermal activation of the hole capture cross sections.