Induced optical reflectivity by local variation of conductivity in MIS structures

Calculations based on theoretical models of metal-insulator-semiconductor structures show that moderate applied potentials can cause sufficiently large induced inversion charge carrier densities at the semiconductor surface to yield reflectivities approaching 100% at the insulator-semiconductor interface. Using p-type silicon as the semiconductor material, positive gate potentials up to 10 V applied to the metal give reflectivities from approximately 15 to nearly 100%. The dependent of doping concentration, insulator thickness, and gate voltage are shown