Elevated pocket pixels, imaging devices and systems including the same and method of forming the same
AssigneeMicron Technology, Inc.
InventorSalman Akram
Life of this patent
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Abstract
An elevated photosensor for image sensors and methods of forming the photosensor. The photosensor may have light sensors having indentation features including, but not limited to, v-shaped, u-shaped, or other shaped features. Light sensors having such an indentation feature can redirect incident light that is not absorbed by one portion of the photosensor to another portion of the photosensor for additional absorption. In addition, the elevated photosensors reduce the size of the pixel cells while reducing leakage, image lag, and barrier problems.
Claims20
A pixel cell, comprising:
- a photosensor formed from a substrate having a first conductivity type and a doped region having a second conductivity type;
- and
- a raised photosensitive region formed completely above a top surface of the substrate,
- wherein the raised photosensitive region includes—
- an indentation feature in an upper surface of the raised photosensitive region,
- an epitaxial layer formed on the top surface of the substrate,
- a hydrogenated amorphous silicon layer formed above the epitaxial layer, and
- a metal conductive layer between the epitaxial layer and the hydrogenated amorphous silicon layer.
A pixel cell, comprising:
- a photosensor formed from a substrate having a first conductivity type and a doped region having a second conductivity type;
- and
- a raised photosensitive region formed completely above a top surface of the substrate,
- wherein the raised photosensitive region includes—
- an indentation feature in an upper surface of the raised photosensitive region, and
- a color filter array formed in the indentation feature.
An imaging system, comprising:
- a pixel array having a plurality of pixel cells arranged in a predetermined number of columns and rows, wherein each pixel cell in the plurality of pixel cells includes a photosensor formed from a substrate having a first conductivity type and a doped region having a second conductivity type;
- a plurality of row and column lines electrically coupled to corresponding pixel cells in the plurality of pixel cells;
- and
- timing and control circuitry configured to read out the charge accumulated in select pixel cells in the plurality of pixel cells via the plurality of row and column lines,
- wherein at least one pixel cell in the plurality of pixel cells further includes a raised photosensitive region formed completely above a top surface of the substrate, and
- wherein the raised photosensitive region includes—
- an indentation feature in an upper surface of the raised photosensitive region,
- an epitaxial layer formed on the top surface of the substrate,
- a hydrogenated amorphous silicon layer formed above the epitaxial layer, and
- a metal conductive layer between the epitaxial layer and the hydrogenated amorphous silicon layer.
Dependencies are inferred from the claim text.