A low smear structure for 2 M-pixel CCD image sensors

The authors have developed a novel smear suppression cell structure, built with a second Al shunt process, for 1-inch optical format FIT-CCD (frame interline transfer charge-coupled device) image sensors with 2 million pixels. The first Al layer works as a photo-shield and the second one is used for V-register drive pulse wiring. With this structure, one can reduce smear levels to less than -110 dB. Moreover, one can achieve levels below -120 dB with an on-chip microlens. >