Photogenerated carrier collection of a solid state image sensor array
AssigneeEastman Kodak Company
InventorsTimothy J. Tredwell, Teh H. Lee, James P. Lavine
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Abstract
An image sensor comprising a semiconductor of a first conductivity type having a plurality of pixels formed thereon; and a region heavily doped with the first conductivity type semiconductor beneath the pixels formed such that there is a gradient formed within the semiconductor below the pixels that is capable of directing photogenerated electrons toward the pixels and away from the heavily doped region. The gradient is formed by having a more lightly doped layer formed upon the heavily doped layer and allowing a gradient to from around the junction of the two layers.
Claims12
An image sensor comprising:
- a semiconductor substrate that is heavily doped of a first conductivity type having a surface with a semiconductor layer that is more lightly doped of the first conductivity type with a plurality of pixels formed within the layer from a second conductivity type that is opposite the first conductivity type;
- and
- a region doped with the first conductivity type semiconductor between the pixels such that the region extends significantly beneath the pixels within the epitaxial layer extending towards the substrate.
An image sensing device comprising:
- a semiconductor substrate heavily doped of a first conductivity type having a layer formed on a surface of the substrate that is more lightly doped than the substrate forming a doping gradient;
- a plurality of pixels formed within the layer;
- and
- a series of isolation regions formed between the pixels and extending significantly deeper into the layer than the pixels, the isolation regions containing a dopant of the first conductivity type that operates in conjunction with a doping gradient formed of the first conductivity type formed from varying doping levels within the substrate and the layer.
Dependencies are inferred from the claim text.