Intra-pixel frame storage element, array, and electronic shutter method including speed switch suitable for electronic still camera applications

摘要

A storage pixel sensor disposed on a semiconductor substrate comprises a MOS capacitor storage element having a diffusion terminal and a gate terminal. A speed node is connected to the diffusion terminal and biased at either a first control potential or a second control potential, the first potential selected to keep the MOS capacitor in a state of inversion, the second potential selected to keep the MOS capacitor in a state of depletion. A photodiode has an anode connected to a reference potential and a cathode. A semiconductor reset switch has a first terminal connected to the cathode and a second terminal connected to a reset reference potential. A semiconductor transfer switch has a first terminal connected to the cathode and a second terminal connected to the gate terminal of the capacitive storage element. A semiconductor amplifier has an input connected to the gate terminal of the capacitive storage element and an output. The semiconductor reset switch and the semiconductor transfer switch each have a control element connected to a control circuit for selectively activating the semiconductor reset switch and the semiconductor transfer switch. A light shield is disposed over a portion of the semiconductor substrate including the second terminal of the semiconductor transfer switch to prevent substantially all photons from entering the portion of the semiconductor substrate. Structures are present for preventing substantially all minority carriers generated in the semiconductor substrate from entering the portion of the semiconductor substrate. A plurality of storage pixel sensors are disposed in an array.