Photonic crystal-based lens elements for use in an image sensor
AssigneeAptina Imaging Corporation
InventorChandra Mouli
Life of this patent
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Abstract
The invention, in various exemplary embodiments, incorporates a photonic crystal lens element into an image sensor. The photonic crystal lens element comprises a substrate and a plurality of pillars forming a photonic crystal structure over the substrate. The pillars are spaced apart from each other. Each pillar has a height and a horizontal cross sectional shape. A material with a different dielectric constant than the pillars is provided within the spacing between the pillars. The photonic crystal element can be a lens configured to focus electromagnetic radiation onto an underlying pixel cell.
Claims33
1-46. (canceled)
A method of forming an image sensor, the method comprising:
- forming an array of pixel cells at a surface of a substrate, each pixel cell formed comprising a photo-conversion device;
- and
- forming at least one photonic crystal lens element over at least one of the pixel cells, the photonic crystal lens element formed to focus light onto at least one pixel cell.
A method of forming an image sensor, the method comprising:
- forming an array of pixel cells at a surface of a substrate, each pixel cell formed comprising a photo-conversion device;
- forming a dielectric layer over the pixel cells;
- and
- forming at least one photonic crystal lens element on the dielectric layer by:
- forming a layer of photonic crystal material on the dielectric layer,
- etching the photonic crystal material layer to form a plurality of pillars spaced apart from each other, each pillar formed having a height and a horizontal cross sectional shape,
- depositing over and between the pillars a layer of a material having a dielectric constant different than a dielectric constant of the pillars,
- configuring the spacing between the pillars, the pillar height, the pillar shape, and the material layer such that the lens element focuses light onto at least one photo-conversion device and
- planarizing the material layer and the pillars.
A method of forming a photonic crystal lens element for an image sensor, the method comprising:
- providing a substrate;
- forming a layer of a photonic crystal material over the substrate;
- patterning the photonic crystal material layer to form a plurality of pillars forming a photonic crystal structure configured to focus electromagnetic radiation, the pillars formed spaced apart from each other and each having a height and a horizontal cross sectional shape;
- and
- placing a material having a lower dielectric constant than a dielectric constant of the pillars within the spacing between the pillars.
Dependencies are inferred from the claim text.