Carrier diffusion degradation of modulation transfer function in charge coupled imagers

Expressions for the modulation transfer function due to minority carrier diffusion in charge coupled imagers are calculated, following the approach used by Crowell and Labuda. Both front and rear optical illumination of the charge coupled imager are considered; for the rear illumination case interference effects are included. The modulation transfer function for high energy electron excitation is also considered. In all cases, the expressions for the modulation transfer function have been evaluated using typical charge coupled imager parameters. The quantum efficiency predicted by the minority carrier diffusion model is also briefly discussed.