UNIT PIXEL OF CMOS IMAGE SENSOR WITH IMPROVED DYNAMIC RANGE

摘要

PURPOSE: A unit pixel of a CMOS image sensor is provided to improve dynamic range and sensibility of the image sensor by reducing the capacitance of a floating diffusion region. CONSTITUTION: A unit pixel comprises a photodiode(21) for storing optical charges, a transfer transistor for transferring the optical charges to a floating diffusion region(23), a capacitor(24) of MIM(Metal-Insulator-Metal) structure connected in series to the floating diffusion region, and a drive transistor. A gate electrode(26a) of the drive transistor is connected to the floating diffusion region. The MIM capacitor is provided with a first electrode(24a) connected to the floating diffusion region and a second electrode(24b).