Space-Charge Plane-Wave Interaction at Semiconductor Substrate Boundary

A theoretical investigation of space-charge plane-wave interaction at dielectric-semiconductor interfaces is presented. A full-wave and charge transport formulation is applied to the analysis of the fundamental mode of propagation in a semiconductor substrate backed with a ground plane. Closed-form expressions for the field components, charge carrier density, and current density are obtained. The reflection coefficients for both H- and E-polarized incident waves were then derived from the field solutions. The interaction between the fields and charge carriers causes a charge accumulation at the semiconductor surface in the case of H-polarization. The effects of the charge accumulation on the reflection coefficient are accounted for. Results indicate that the space charge exerts a weak effect on the reflection coefficient and a strong screening effect on the normal component of the electric field. The tangential component, however, is mainly governed by energy dissipation effect resulting from the conduction current.