Wide dynamic range CMOS active pixel sensor with sensitivity control gate

This paper proposes a wide dynamic range CMOS APS pixel array using a sensitivity control gate (SCG) without much degradation in optical performance. The proposed method is realized by adding a polysilicon control gate over the photodiode (PD) area, which adds MOS capacitance to the original PD capacitance. While a single control gate over PD can maximize the range of capacitance PD can have, it also has the maximum light absorption in the gate. By using SCG with holes, fringing capacitance of the control gate can be utilized to effectively sustain the total capacitance range while increasing the QE.