Analytic representations of the dielectric functions of crystalline and amorphous Si and crystalline Ge for very large scale integrated device and structural modeling

Various representations of the dielectric functions of semiconducting materials have been proposed. We compare five different models for representing the dielectric functions of crystalline (c-) Si, amorphous (a-) Si, and c-Ge from 1.5 to 6.0 eV. The four-oscillator critical point with parity plus one-dimensional tight-binding model (CPP-1D) best represents c-Si. Different models best represent a-Si and c-Ge. These representations provided a basis for modeling variations encountered in semiconductor manufacturing.