Image sensor with raised photosensitive elements
AssigneeOmni Vision Technologies, Inc.
InventorShenlin Chen
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Abstract
An image sensor having a pixel array comprises periphery elements formed over a substrate, an oxide layer formed over the periphery elements, an epitaxial layer formed in an opening in the oxide layer in a pixel array area, and a plurality of photosensitive elements of the pixel array formed in the epitaxial layer. Formation of an initial metallization layer occurs after the formation of the photosensitive elements in the epitaxial layer. The photosensitive elements can thus be formed in the epitaxial layer at a higher level within an image sensor stack than that of the initial metallization layer. This advantageously allows stack height and pixel size to be reduced, and fill factor to be increased. The image sensor may be implemented in a digital camera or other type of digital imaging device.
Claims15
An image sensor having a pixel array, the image sensor comprising:
- a plurality of periphery elements formed over a substrate;
- an oxide layer formed over the periphery elements, the oxide layer including a pixel array area having an opening;
- an epitaxial layer formed in the opening of the oxide layer, the epitaxial layer including at least one well extending through a thickness of the epitaxial layer into the substrate, wherein the epitaxial layer includes at least one of a transfer gate, a reset transistor, a select transistor, and a source follower output transistor;
- and
- a plurality of photosensitive elements of the pixel array area formed within the at least one well in the epitaxial layer.
A digital imaging device comprising:
- an image sensor having a pixel array;
- and
- one or more processing elements configured to process outputs of the image sensor to generate a digital image, wherein the image sensor comprises:
- a plurality of periphery elements formed over a substrate,
- an oxide layer formed over the periphery elements, the oxide layer including a pixel array area having an opening,
- an epitaxial layer formed in the opening of the oxide layer, the epitaxial layer including at least one well extending through a thickness of the epitaxial layer into the substrate, wherein the epitaxial layer includes at least one of a transfer gate, a reset transistor, a select transistor, and a source follower output transistor, and
- a plurality of photosensitive elements of the pixel array area formed within the at least one well in the epitaxial layer.
Dependencies are inferred from the claim text.