Spectral response nonuniformity analysis of charge-coupled imagers

A single pixel spectral response model for front-side illuminated visible imaging charge-coupled devices was used to interpret measurements of pixel-to-pixel spectral response variations in an area and a linear charge-coupled imager. Destructive analysis was performed on both devices from which the polysilicon (gate) and oxide layer thicknesses were inferred. The pertinent layer thicknesses in the spectral response models were systematically varied until the best agreement between the modeled response and experimental data were obtained. This matching procedure was quite successful for the interference fringe maxima and minima locations but less successful in matching the overall spectral envelope. Reasonable agreement between the measured (destructive analysis) and model-inferred layer thicknesses was obtained. The model was also useful in interpreting some unusual global characteristics found in the area imager.