We discuss a model for the on-site matrix elements of the sp 3 d 5 s * tight-binding hamiltonian of a strained diamond or zinc-blende crystal or nanostructure. This model features on-site, off-diagonal couplings between the s, p and d orbitals, and is able to reproduce the effects of arbitrary strains on the band energies and effective masses in the full Brillouin zone. It introduces only a few additional parameters and is free from any ambiguities that might arise from the definition of the macroscopic strains as a function of the atomic positions. We apply this model to silicon, germanium and their alloys as an illustration. In particular, we make a detailed comparison of tight-binding and ab initio data on strained Si, Ge and SiGe.

No abstract

No abstract

No abstract

Abstract-Complementary MOS device electrical performances are considerably affected by the degradation of the oxide layers and Si/SiO 2 interfaces. A general expression for electrically stressed MOS impedance has been derived and applied within the nonradiative multiphonon theory of carrier capture/emission at oxide defects. The capacitance and the conductance of aged MOS field-effect transistor oxides, and their dependences on bias voltage, temperature, and stress conditions have been investigated.