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US 4,873,561 AGranted
High dynamic range charge-coupled device
OwnerDavid D. Weninventor
Life of this patent
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Abstract
A high dynamic range charge collection circuit is described which includes additional electrodes between the photogate and the transfer gate electrode to create charge transfer wells of different depths. The charge-coupled device has a nonlinear relationship between the charge transferred out of the sensing region and the charge generated in the photosite.
Claims17
A semiconductor structure comprising:
- a semiconductor substrate;
- photogate means disposed in proximity to the substrate for creating a first depletion region in the substrate of first depth for the accumulation of charge in response to ambient electromagnetic radiation, the first depletion region being capable of containing a first quantity of charge;
- storage gate means, spaced apart from the photogate means, disposed in proximity to the substrate for creating a second depletion region in the substrate of second depth, the second depth being greater than the first depth and the second depletion region being capable of containing a second quantity of charge less than the first quantity;
- and
- sampling gate means disposed between the photogate means and the storage gate means for controllably isolating the second depletion region from the first depletion region to allow transfer of the second quantity of charge from the second epletion region without the first quantity of charge.
2 more elements
A charge-coupled device comprising:
- a semiconductor substrate;
- a photogate electrode disposed in proximity to the substrate for establishing a first depletion region of first potential depth in the substrate capable of containing a first quantity of charge;
- a storage electrode spaced apart from the photogate electrode and disposed in proximity to the substrate for establishing a second depletion region of second potential depth in the substrate capable of containing a second quantity of charge less than the first quantity;
- and
- an intervening sampling electrode disposed in proximity to the substrate and separating the storage electrode from the photogate electrode, the sampling electrode for controllably isolating the first depletion region from the second depletion region.
2 more elements
A method of increasing the dynamic range of a charge-coupled device comprising:
- in a semiconductor substrate establishing a first depletion region capable of accumulating a first quantity of charge in response to ambient light;
- establishing a second depletion region capable of containing a second quantity of charge smaller than the first quantity, the second depletion region being spaced from the first depletion region;
- establishing a variable potential depth depletion region between the first and the second depletion regions;
- raising the potential of the variable depth depletion region to allow charge to flow from the first depletion region to the second depletion region;
- lowering the potential of the variable depth depletion region to prevent any remaining charge in the first depletion region from flowing into the second depletion region;
- and
- transferring charge from the second depletion region out of that region.
4 more elements
Dependencies are inferred from the claim text.