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US 2003/0211702 A1Published application
Dual trench isolation using single critical lithographic patterning
AssigneeIntel Corporation
InventorsKrishna Parat, Kiran Pangal, Allen Lu
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Abstract
A method and apparatus for forming shallow and deep isolation trenches in a substrate so that the shallow and deep isolation trenches are aligned without mis-registration. The method includes forming a plurality of shallow trenches, covering a portion of the plurality of shallow trenches, then etching the uncovered shallow trenches to create deeper trenches.
Claims20
A method, comprising:
- forming a mask layer on a substrate having a first area and a second area;
- forming a first photoresist layer over said mask layer;
- patterning the first photoresist layer to form a photoresist-mask layer over the first and second areas with the photoresist-mask layer having a plurality of openings;
- etching said mask layer and substrate, between the plurality of openings, to a first depth, to form a plurality of trenches in the substrate, said plurality of trenches defining a plurality of substrate structures covered by the mask layer;
- forming a second photoresist layer over said first area and leaving the trenches and substrate structures in the second area exposed;
- and
- etching the exposed trenches in the second area to a second depth, said mask layer protecting the substrate structures in the second area from being etched.
4 more elements
A method, comprising:
- forming a plurality of shallow isolation trenches in a substrate;
- covering a portion of the plurality of shallow isolation trenches, resulting in covered shallow isolation trenches and uncovered shallow isolation trenches;
- and
- etching the uncovered shallow isolation trenches to form a plurality of deep isolation trenches.
1 more element
A method, comprising:
- forming a mask layer on a substrate;
- patterning a first photoresist layer on the mask layer;
- etching the mask layer and substrate to a first depth, forming a plurality of shallow isolation trenches in the substrate, said plurality of shallow isolation trenches defining a plurality of masked active regions between the trenches, said masked active regions masked by the mask layer;
- removing the first photoresist layer;
- forming a second photoresist layer to cover a region of the shallow isolation trenches and masked active regions, thus forming a region of covered shallow isolation trenches and masked active regions and a region of uncovered shallow isolation trenches and masked active regions;
- and
- etching the uncovered shallow isolation trenches to a second depth to form a plurality of deep isolation trenches, said mask layer acting as an etch-stop to protect the uncovered active regions during etching, the plurality of uncovered masked active regions being directly aligned to the plurality of covered masked active regions.
4 more elements
An isolation structure, comprising:
- a first area and a second area;
- a plurality of shallow isolation trenches in the first area;
- and
- a plurality of deep isolation trenches in the second area, the deep isolation trenches and the shallow isolation trenches being perfectly aligned.
1 more element
Dependencies are inferred from the claim text.