Transmittance of air/SiO/SUB 2//polysilicon/SiO/SUB 2//Si structures

Abstract

Polycrystalline silicon films are presently used as the semitransparent gate electrodes in front-illuminated charge-coupled device (CCD) and charge-injection device (CID) image sensors. The transmittance of air/SiO/SUB 2//polysilicon/SiO/SUB 2//Si structures is calculated in spectral region between 0.4 and 1.0 /spl mu/. A proper choice of the thicknesses of the oxide films can substantially increase the transmittance over a narrow wavelength band or over the entire wavelength region of interest.