Imaging pixels with non-destructive readout capabilities
AssigneeSemiconductor Components Industries, LLC
InventorChristopher PARKS
Life of this patent
Estimating the term…
Abstract
An image sensor may include imaging pixels with non-destructive readout capabilities. Each imaging pixel may include a substrate having a photosensitive area that generates charge in response to incident light. The charge may accumulate at a front side of the substrate adjacent to a floating gate. The voltage of the floating gate may depend on how much charge is accumulated. The voltage of the floating gate may be repeatedly sampled to monitor the amount of incident light received over time. A first reset transistor may clear the substrate of accumulated charge. A second reset transistor may reset the voltage of the floating gate. The imaging pixel may be split between multiple wafers if desired and may include nMOS and pMOS transistors.
Claims21
An image sensor comprising:
- a semiconductor substrate having first and second opposing surfaces;
- a photosensitive area in the semiconductor substrate, wherein the photosensitive area is configured to generate charge in response to incident light during an integration period;
- a floating gate formed adjacent to the first surface of the semiconductor substrate, wherein the charge generated by the photosensitive area accumulates at the first surface of the semiconductor substrate adjacent to the floating gate;
- and
- a source follower transistor, wherein the floating gate is electrically connected to a gate of the source follower transistor.
An image sensor comprising:
- a substrate having first and second opposing sides;
- a photosensitive area in the substrate that is configured to generate charge in response to incident light during an integration time;
- a floating gate on the first side of the substrate, wherein the charge generated by the photosensitive area accumulates in the substrate adjacent to the floating gate;
- and
- readout circuitry configured to sample a voltage of the floating gate multiple times during the integration time.
An image sensor comprising:
- a first substrate;
- a photosensitive area formed in the first substrate;
- a floating gate adjacent to the photosensitive area in the first substrate;
- a second substrate;
- a source follower transistor in the second substrate;
- and
- a metal interconnect layer between the first and second substrates that electrically connects the floating gate in the first substrate to a gate of the source follower transistor in the second substrate.
Dependencies are inferred from the claim text.