Full nanosheet airgap spacer
AssigneeInternational Business Machines Corporation
InventorsJingyun Zhang, Ruilong Xie, Reinaldo Vega, Kangguo Cheng, Lan Yu
Life of this patent
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Abstract
Embodiments disclosed herein include a nanosheet transistor for reducing parasitic capacitance. The nanosheet transistor may include a spacer region between a high-k metal gate and an epitaxial layer. The spacer region may include a first nanosheet stack with a first nanosheet and a second nanosheet. The spacer region may include an inner spacer region between the first nanosheet and the second nanosheet, and a side subway region located along an edge of the first nanosheet, the inner spacer region, and the second nanosheet.
Claims20
A nanosheet transistor for reducing parasitic capacitance, comprising:
- a spacer region between a high-k metal gate and an epitaxial layer, wherein the spacer region comprises:
- a first nanosheet stack comprising a first nanosheet and a second nanosheet;
- an inner spacer region between the first nanosheet and the second nanosheet;
- and
- a side subway region located along an edge of the first nanosheet, the inner spacer region, and the second nanosheet, wherein the side subway region contacts a shallow trench isolation below the spacer region.
A method of fabricating a nanosheet transistor, comprising:
- forming a nanosheet stack comprising sacrificial inner spacers and nanosheets;
- forming an epitaxial layer adjacent to the nanosheet stack;
- indenting the epitaxial layer to expose the sacrificial inner spacer at a corner etch;
- and
- removing the sacrificial inner spacer to form an air gap around the nanosheets.
A nanosheet transistor for reducing parasitic capacitance, comprising:
- a spacer region between a high-k metal gate and an epitaxial layer, wherein the spacer region comprises:
- a first nanosheet stack comprising a first nanosheet and a second nanosheet;
- an inner spacer region between the first nanosheet and the second nanosheet, wherein the inner spacer region comprises an air gap over a width of the first nanosheet and the second nanosheet, wherein the air gap contacts a shallow trench isolation below the first nanosheet stack.
Dependencies are inferred from the claim text.