PHOTO RESPONSE ANALYSIS IN CCD IMAGE SENSORS WITH A VOD STRUCTURE

Photo response in CCD image sensors with Vertical-Overflow-Drain (VOD) was analyzed in an attempt to discover a way to lessen the photo resp onse rise that accompanies increasing incident light intensity in the saturation region. A photo response analysis based on transistor I-V c haracteristics revealed that the extent of rise in the saturation regi on is uniquely determined by the non-ideality factor and temperature. Calculating of the non-ideality factor and its dependence on P-well im purity concentration and layer thickness further revealed that fabrica tion of P-wells with lower impurity concentrations and thicker layers would be effective in suppressing photo response rise.