Intrinsic and dopant-enhanced solid-phase epitaxy in amorphous germanium

Abstract

The kinetics of intrinsic and dopant-enhanced solid-phase epitaxy (SPE) is studied in amorphous germanium (a-Ge) layers formed by ion implantation on 100 Ge substrates. The SPE rates were measured with a time-resolved reflectivity (TRR) system between 300 and 540°C and found to have an activation energy of (2.15±0.04) eV. To interpret the TRR measurements the refractive indices of the a-Ge layers were measured at the two wavelengths used, 1.152 and 1.532 μm. For the first time, SPE rate measurements on thick a-Ge layers (>3 μm) have also been performed to distinguish between bulk and near-surface SPE growth rate behavior. Possible effects of explosive crystallization on thick a-Ge layers are..