<title>Surface channel clocked antiblooming technique for area-array CCD image sensors</title>

Abstract

Implementation ofover-illumination protection on area array image sensors has typically involved significant modifications to device design and/or processing. These modifications have caused degradation of device performance, for example, lateral antiblooming reduces fill factor and vertical antiblooming reduces near infra-red (NIR) quantum efficiency (QE).Clocked antiblooming is a technique that does not require any processing or design changes and does not degrade fill factor or MR QE. The technique involves clocking the imaging phases into, and out of, inversion during the integration time and relying on the surface recombination of electrons and holes to eliminate excess signal charge.The technique described in this paper allows clocked antiblooming with surface channel operation thus permitting large full well packets with small pixel geometries. Although surface channel operation is less efficient in terms of charge transfer efficiency, there are some applications where maximum full well charge storage capability is important.