October 6, 2009, Stockholm, It was a historic moment for digital cameras when their shutters opened for the fraction of a second to capture the committee, award the coveted Nobel Prize to the ones who invented the electronic eyes. Had it not been the duo Willard Boyle and George Smith, those cameras might still have been shuttering light on a photosensitive film and then drying them on rails in the dark room. By inventing the ‘Charge Coupled Device’ and predicting its applications way back in 1969, Boyle and Smith opened up the domain of solid state devices for imaging and memory applications.
Advent of CMOS technology in eighties led to the phenomenal growth in semiconductor industry. Transistors have become smaller, faster, consume less power, and are cheaper to manufacture. It is CMOS technology which has enabled very high integration on the chips leading to modern high performance, miniaturized integrated circuits. Apart from the valuable contribution in miniaturization of integrated circuits, CMOS technology found applications in sensing applications. CMOS technology has been adopted to design sensors, especially in the field of imaging. Due to the wide usage of CMOS based image sensors, CMOS sensors are often considered to be a synonym of CMOS based image sensors and have emerged as a competitor to CCD based image sensors.