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US 11,901,235 B2Granted
Ion implantation for nano-FET
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsYu-Chang Lin, Chun-Feng Nieh, Huicheng Chang, Yee-Chia Yeo
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Abstract
A nanoFET transistor includes doped channel junctions at either end of a channel region for one or more nanosheets of the nanoFET transistor. The channel junctions are formed by a iterative recessing and implanting process which is performed as recesses are made for the source/drain regions. The implanted doped channel junctions can be controlled to achieve a desired lateral straggling of the doped channel junctions.
Claims20
A device comprising:
- a first nanostructure, the first nanostructure comprising a first doped channel junction at either end, doped by a first dopant;
- a second nanostructure over the first nanostructure, the second nanostructure comprising a second doped channel junction at either end, doped by a second dopant, wherein the first dopant and the second dopant comprise different materials;
- a gate structure disposed over the first nanostructure and the second nanostructure, the gate structure extending between the first nanostructure and the second nanostructure;
- an epitaxial region adjacent the gate structure, the epitaxial region contacting the first nanostructure and the second nanostructure;
- and
- an inner spacer disposed at either end of the first nanostructure, the inner spacer extending between the first nanostructure and the second nanostructure, the inner spacer interposed between a gate dielectric of the gate structure and the epitaxial region, wherein an interface between the epitaxial region and the inner spacer is free of the first dopant or the second dopant.
3 more elements
A transistor comprising:
- a first nanostructure, the first nanostructure comprising first doped channel junctions at each end, the first nanostructure having a first undoped channel length between the first doped channel junctions;
- a second nanostructure over the first nanostructure, the second nanostructure comprising second doped channel junctions at each end, the second nanostructure having a second undoped channel length between the second doped channel junctions, wherein a first lateral depth of the first doped channel junctions is a different value than a second lateral depth of the second doped channel junctions;
- a third nanostructure, the third nanostructure interposed between the first nanostructure and the second nanostructure, the third nanostructure having a third undoped channel length between a first end of the third nanostructure and a second end of the third nanostructure, wherein each of the first nanostructure, second nanostructure, and third nanostructure have the same length, wherein the third undoped channel length is greater than or less than both the first undoped channel length and the second undoped channel length or wherein the third undoped channel length is the same as the first undoped channel length and the second undoped channel length is either greater than or less than the first undoped channel length;
- a gate structure disposed over the first nanostructure and the second nanostructure, the gate structure wrapping around the first nanostructure and the second nanostructure;
- and
- a first epitaxial region adjacent the gate structure, the first epitaxial region contacting the first nanostructure and the second nanostructure.
3 more elements
A method comprising:
- forming multiple nanostructures over a substrate;
- forming a dummy gate structure over the multiple nanostructures;
- performing a first angled ion implantation to implant first dopants under the dummy gate structure into a first nanostructure of the multiple nanostructures;
- etching the first nanostructure to remove a first portion of the first nanostructure exposed from the dummy gate structure, a second portion of the first nanostructure under the dummy gate structure remaining as a first doped channel region;
- performing a second angled ion implantation to implant second dopants under the dummy gate structure into a second nanostructure;
- etching the second nanostructure to remove a first portion of the second nanostructure exposed from the dummy gate structure and the first nanostructure, a second portion of the second nanostructure under the dummy gate structure remaining as a second doped channel region;
- and
- forming a source region or a drain region contacting the first doped channel region and the second doped channel region.
5 more elements
Dependencies are inferred from the claim text.