Residual Damage in Heavily Germanium-Doped Silicon

Abstract

ABSTRACTCross-sectional transmission electron microscopy (XTEM) studies have shown that two distinct damage regions are created when germanium is implanted into single-crystal silicon in high doses and subsequently annealed at high temperatures. The first layer extends approximately 90–95 nm into silicon for an implant energy of 120 keV. The second region is an end-of-range damage region located 200 nm from the silicon surface for the same implantation energy. Neither low-dose, low-energy boron implantation nor the type of cap layers used during annealing alter the damage pattern. Although the dose of the Ge implants is the major factor in the formation of the continuous damage layer, high oxygen concentration at the surface may also contribute to this effect.