Strained SiGe-alloy layers formed by solid phase epitaxial growth of Ge + ion implanted silicon

Abstract

Strained SiGe-alloy layers in Si(001) crystals with a maximum Ge concentration of 14 at.% were formed by ion implantation and solid phase epitaxial growth. The ion implantation was carried out with 40 keV 74Ge + ions and a dose of 2.2 × 10 16 ions/cm 2. The samples were annealed at 850°C for 20 min in a conventional furnace in a flow of nitrogen gas. Rutherford backscattering spectrometry and transmission electron microscopy show that the alloy layers are of good crystal quality with no extended defects. The measurements also show that the alloy layer is tetragonally distorted, i.e. the alloy layer is strained.