Stress memorization technique for strain coupling enhancement in bulk finFET device
First Claim
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1. A method for forming strained fins, comprising:
- recessing a dielectric fill into trenches in a substrate to form shallow trench isolation regions, the trenches being etched into the substrate to form fins;
etching the fins above the shallow trench isolation regions to form a staircase fin structure with narrow top portions of the fins;
forming gate structures over the top portions of the fins;
epitaxially growing raised source and drain regions on opposite sides of the gate structure; and
performing a pre-amorphization implant to generate defects in the substrate to induce strain and to couple the strain into the top portions of the fins.
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Abstract
A method for forming strained fins includes etching trenches in a bulk substrate to form fins, filling the trenches with a dielectric fill and recessing the dielectric fill into the trenches to form shallow trench isolation regions. The fins are etched above the shallow trench isolation regions to form a staircase fin structure with narrow top portions of the fins. Gate structures are formed over the top portions of the fins. Raised source ad drain regions are epitaxially grown on opposite sides of the gate structure. A pre-morphization implant is performed to generate defects in the substrate to couple strain into the top portions of the fins.
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Citations
16 Claims
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1. A method for forming strained fins, comprising:
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recessing a dielectric fill into trenches in a substrate to form shallow trench isolation regions, the trenches being etched into the substrate to form fins; etching the fins above the shallow trench isolation regions to form a staircase fin structure with narrow top portions of the fins; forming gate structures over the top portions of the fins; epitaxially growing raised source and drain regions on opposite sides of the gate structure; and performing a pre-amorphization implant to generate defects in the substrate to induce strain and to couple the strain into the top portions of the fins. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method for forming strained fins, comprising:
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forming a first dielectric layer on a bulk substrate; forming a second dielectric layer on the first dielectric layer; forming mandrels with sidewall spacers; removing the mandrels; etching the second dielectric layer and the first dielectric layer in accordance with the sidewall spacers to form an etch mask; etching trenches in the bulk substrate to form fins using the etch mask; filling the trenches with a dielectric fill; recessing the dielectric fill into the trenches to form shallow trench isolation regions; etching the fins above the shallow trench isolation regions to form a staircase fin structure with narrow top portions of the fins; forming gate structures over the top portions of the fins; epitaxially growing raised source ad drain regions on opposite sides of the gate structure; performing a pre-amorphization implant to generate defects in the substrate to induce strain and couple the strain into the top portions of the fins; and performing a stress memorization technique (SMT) anneal to propagate the strain after the pre-amorphization implant through the fins from the substrate. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification