Intrinsic and dopant-enhanced solid phase epitaxy in amorphous germanium

Abstract

The kinetics of intrinsic and dopant-enhanced solid phase epitaxy (SPE) are studied in thick amorphous germanium (a-Ge) layers formed by ion implantation on Ge substrates. The SPE rates for H-free Ge were measured with a time-resolved reflectivity (TRR) system in the temperature range 300 - 540 °C and found to have an activation energy of (2.15 ± 0.04) eV. Dopant enhanced SPE was measured in a-Ge layers containing a uniform concentration profile of implanted As spanning the concentration regime 1 -10 × 10 19 cm3. The generalized Fermi level shifting model shows excellent fits to the data. © 2008 Materials Research Society.