Stabilization of Ge-rich defect complexes originating fromEcenters inSi1−xGex:P

Abstract

Thermal evolution of vacancy complexes was studied in P-doped $([\text{P}]={10}^{18}\text{ }{\text{cm}}^{\ensuremath{-}3})$ proton irradiated ${\text{Si}}_{1\ensuremath{-}x}{\text{Ge}}_{x}$ with Ge contents of 10%, 20%, and 30% in the range of $250--350\text{ }\ifmmode^\circ\else\textdegree\fi{}\text{C}$ using positron annihilation spectroscopy. The radiation damage recovers in the course of anneals but the final state differs from that in as-grown samples indicating the presence of small Ge clusters in the samples, contrary to the initially random Ge distribution. The activation energy for the annealing process was estimated to be $1.4\ifmmode\pm\else\textpm\fi{}0.3\text{ }\text{eV}$ and attributed to the dissociation energy of the vacancy-phosphorus-germanium $(V\text{-P-Ge})$ complex.