Lattice Compression from Conduction Electrons in Heavily Doped Si:As

Abstract

High-resolution x-ray scattering measurements on heavily doped Si:As (5\ifmmode\times\else\texttimes\fi{}${10}^{21}$ As ${\mathrm{cm}}^{\ensuremath{-}3}$) show lattice compression relative to pure silicon, $\frac{\ensuremath{\Delta}a}{a}=\ensuremath{-}0.0019\ifmmode\pm\else\textpm\fi{}0.0003$, although extended x-ray-absorption fine-structure measurements show that the As-Si bond length is 0.06\ifmmode\pm\else\textpm\fi{}0.02 \AA{} greater than the usual Si-Si bond length. The overall lattice compression is attributed to increased population of conduction-band states which reduces Si-Si bond lengths. These measurements provide the first direct measurement of the hydrostatic deformation potential for the conduction-band edge in silicon, +3.3\ifmmode\pm\else\textpm\fi{}0.7 eV.