Lux transfer: Complementary metal oxide semiconductors versus charge-coupled devices

Abstract

We compare the performance of competing CCD and CMOS imaging sensors including backside-illuminated devices. Comparisons are made through a new performance transfer curve that shows at a glance performance deficiencies for any given pixel architecture ana- lyzed or characterized. Called lux transfer, the curve plots SNR as a function of absolute light intensity for a family of exposure times over the sensor's dynamic range (i.e., read noise to full well). Critical performance parameters on which the curve is based are reviewed and analytically described (e.g., quantum efficiency (QE), pixel nonuniformity, full well, dark current, read noise, modulation transfer function (MTF), etc.). Be- sides SNR, many by-products come from lux transfer including dynamic range, responsivity (e 2 /lux-s), charge capacity, linearity, and Interna- tional Organization for Standards (ISO) rating. Experimental data gener- ated by 4 mm, three transistor (3T) pixel digital video graphics array (DVGA) and a 5.6-mm, 3T pixel digital extended graphics array (DXGA) CMOS sensors are presented that demonstrate lux transfer use. © 2002