Radiation effects on a radiation-tolerant CMOS active pixel sensor

A comprehensive cobalt60, proton, and heavy ion evaluation of the Fillfactory STAR-250 CMOS active pixel sensor has been performed for space applications up to 100 krd(Si). It was possible to eliminate image lag by adjustment of the bias voltage and this allowed a reduction in proton-induced dark signal. Both cobalt60 and proton irradiation produced a decrease in responsivity, which is thought to be due to total dose effects. There was also an increase in photoresponse nonuniformity (PRNU). No major single event effects (latch-up or functional interrupt) where seen at the maximum linear energy transfer (LET) of 68MeV/(mg/cm/sup 2/).