A CMOS image sensor with a double-junction active pixel

A CMOS image sensor that employs a vertically integrated double-junction photodiode structure is presented. This allows color imaging with only two filters. The sensor uses a 184*154 (near-QCIF) 6-transistor pixel array at a 9.6-(mu)m pitch implemented in 0.35(mu)m technology. Results of the device characterization are presented. The imaging performance of an integrated two-filter color sensor is also projected, using measurements and software processing of subsampled images from the monochrome sensor with two color filters.