Determination of conduction band edge characteristics of strained Si/Si_1-xGe_x

The feature of conduction band (CB) of Tensile-Strained Si(TS-Si) on a relaxed Si_1 - xGe_x substrate is systematically investigated, including the number of equivalent CB edge energy extrema, CB energy minima, the position of the extremal point, and effective mass. Based on an analysis of symmetry under strain, the number of equivalent CB edge energy extrema is presented; Using the K\cdotP method with the help of perturbation theory, dispersion relation near minima of CB bottom energy, derived from the linear deformation potential theory, is determined, from which the parameters, namely, the position of the extremal point, and the longitudinal and transverse masses (m_\rm l^\ast and m_\rm t^\ast ) are obtained.