Semiconductor device and methods of forming the same

Abstract

A pixel sensor includes a first source-follower gate and a second-follower gate respectively connected to a photodiode and to an overflow capacitor such that the first source-follower gate may read a voltage of the photodiode, while the second source-follower gate simultaneously reads a voltage of the overflow capacitor. The arrangement including the first and second source-follower gates permits the photodiode and overflow capacitor voltages to be read at the same time, so that the time to read the photodiode and overflow capacitor voltages (e.g., read-out speed) is equal to the time during which the photodiode and overflow capacitor voltages are simultaneously read. The simultaneous reading of photodiode and overflow capacitor voltages increases an image sensor device frame rate in comparison to when the photodiode and overflow capacitor voltages are read in sequence, thereby increasing the rate at which an image sensor device captures images, and improving image sensor device performance.