A 2.8 μm Pixel for Time of Flight CMOS Image Sensor with 20 ke-Full-Well Capacity in a Tap and 36 % Quantum Efficiency at 940 nm Wavelength

Abstract

A 2.8μm 4-tap global shutter pixel has been realized for a compact and high-resolution time of flight (ToF) CMOS image sensor. 20,000 e- of high full-well capacity (FWC) per a tap is obtained by employing a supplementary MOS capacitor. 36% of high quantum efficiency (QE) has been achieved by backside scattering technology (BST) and thick silicon process. In addition, demodulation contrast (DC) is improved to 86 % by additional deep photodiode doping process for static potential gradient in a photodiode.