A 3μm Pixel Device for Peak Power Mitigation of Global-Shutter Indirect Time of Flight Image Sensor

This paper presents a $3 \mu \mathrm{~m}$ pinned photodiode(PPD) pixel device for global-shutter indirect time of flight(iToF) sensor. A trapezoidal-shaped PD-layer and a non-uniform doped charge transfer gate channel are proposed to improve the charge transfer speed and efficiency, which adapt with higher threshold voltage of charge transfer transistor(TX) to reduce the leakage. As a result, the amplitude of TX gate voltage can be reduced, avoiding negative voltage. The proposed pixel device has been designed in a $0.15 \mu \mathrm{~m}$ CMOS image sensor(CIS) process. The simulation results show that full-well capacity (FWC) achieves 12233 e -, with the charge transfer time of 3.33 ns. The high/low level gate voltage of TX can be reduced to $2.9 / 0 \mathrm{~V}$, which is helpful to mitigate the peak power of global-shutter iToF sensor.