NFETs using gate induced stress modulation
First Claim
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1. A method for manufacturing an integrated circuit comprising a plurality of semiconductor devices including an n-type transistor and a p-type transistor on a semiconductor wafer, the method comprising:
- covering the p-type transistor with a mask;
oxidizing a portion of the gate polysilicon of the n-type transistor, such that tensile mechanical stresses are formed within a channel of the n-type transistor; and
removing, after the oxidizing step, oxide formed during the oxidizing step from above the gate polysilicon of the n-type transistor,wherein the oxidizing step results in formation of a bird'"'"'s beak in an edge of the gate polysilicon between the gate polysilicon and a spacer of the n-type transistor and the removing step preserves the bird'"'"'s beak.
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Abstract
A method for manufacturing an integrated circuit comprising a plurality of semiconductor devices including an n-type field effect transistor and a p-type field effect transistor by covering the p-type field effect transistor with a mask, and oxidizing a portion of a gate polysilicon of the n-type field effect transistor, such that tensile mechanical stresses are formed within a channel of the n-type field effect transistor.
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Citations
35 Claims
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1. A method for manufacturing an integrated circuit comprising a plurality of semiconductor devices including an n-type transistor and a p-type transistor on a semiconductor wafer, the method comprising:
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covering the p-type transistor with a mask; oxidizing a portion of the gate polysilicon of the n-type transistor, such that tensile mechanical stresses are formed within a channel of the n-type transistor; and removing, after the oxidizing step, oxide formed during the oxidizing step from above the gate polysilicon of the n-type transistor, wherein the oxidizing step results in formation of a bird'"'"'s beak in an edge of the gate polysilicon between the gate polysilicon and a spacer of the n-type transistor and the removing step preserves the bird'"'"'s beak. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 13, 14, 15, 17, 18, 21)
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10. A method for manufacturing an integrated circuit comprising a plurality of semiconductor devices including an n-type transistor and a p-type transistor on a semiconductor wafer, the method comprising:
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covering the p-type transistor with a mask; oxidizing a portion of a gate polysilicon of the n-type transistor, such that tensile mechanical stresses are formed within a channel of the n-type transistor, wherein the oxidizing results in formation of a bird'"'"'s beak in an edge of the gate polysilicon; removing, after the oxidizing step, oxide above the gate polysilicon of the n-type transistor, the removing step comprising removing a deposited oxide from above the gate polysilicon of the n-type field effect transistor by etching the deposited oxide from above the gate polysilicon of the n-type field effect transistor; and depositing silicide material on at least the portion of the gate polysilicon of the n-type field effect transistor. - View Dependent Claims (11, 12)
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16. A method for manufacturing an integrated circuit comprising a plurality of semiconductor devices including an n-type field effect transistor and a p-type field effect transistor on a semiconductor wafer, the method comprising forming oxide between a side of a gate polysilicon and a spacer of the n-type field effect transistor, oxidizing a portion of the gate polysilicon of the n-type field effect transistor, such that tensile mechanical stresses are formed within a channel of the n-type field effect transistor, without creating additional tensile stresses in a channel of the p-type field effect transistor,, and removing oxide formed during the oxidizing step from above the gate polysilicon of the n-type field effect transistor, wherein the oxidizing step results in formation of a bird'"'"'s beak in an edge of the gate polysilicon between the gate polysilicon and the spacer and the removing step preserves the bird'"'"'s beak.
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19. A method for manufacturing an integrated circuit comprising a plurality of semiconductor devices including an n-type transistor and a p-type transistor on a semiconductor wafer, the method comprising:
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forming a first oxide above a gate polysilicon and between a side of the gate polysilicon and a spacer of the n-type transistor, masking the p-type transistor; removing the first oxide from above the pate polysilicon of the n-type transistor while allowing the first oxide to remain between the side of the gate polysilicon and the spacer, oxidizing a portion of the gate polysilicon of the n-type transistor, such that tensile mechanical stresses are formed within a channel of the n-type transistor; and removing the oxide formed during the oxidizing from above the gate polysilicon of the n-type transistor, wherein, after the removing of the oxide formed during the oxidizing, a bird'"'"'s beak remains in the gate polysilicon between the gate polysilicon and the spacer of the n-type transistor. - View Dependent Claims (20)
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22. A method of forming a device, comprising:
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forming a PFFT and NFFT structure each having polysilicon gate structures; depositing a metal or a low resistance material to a thickness of about 30 Å
to about 200 Å
across the polysilicon gate structures and exposed surfaces;removing unreacted metal while formed silicide remains on the polysilicon gate structures; planarizing an oxide fill formed over the silicide; removing the silicide on top of the polysilicon gate structures using a selective etch; protecting the PFET polysilicon gate structures and exposing the NFET polysilicon gate structures; oxidizing the NFET, while protecting the PFET with a mask, such that the polysilicon gate structures of the PFET are not oxidized while oxide is deposited on the polysilicon gate structures of the NFET resulting in a formation of a vertical bird'"'"'s beak in an edge of polysilicon of the polysilicon gate structures of the NFET. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
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Specification