Theory of deep impurities in silicon-germanium alloys

Abstract

Calculations of the deep-energy levels of substitutional ${\mathrm{sp}}^{3}$-bonded defects in ${\mathrm{Si}}_{x} {\mathrm{Ge}}_{1\ensuremath{-}x}$ alloys suggest that the standard shallow dopants As and P and isoelectronic C defect may become deep traps for $x\ensuremath{\simeq}0.2$.