Nanowire fet including nanowire channel spacers
AssigneeInternational Business Machines Corporation
InventorSoon-Cheon Seo
Life of this patent
Estimating the term…
Abstract
A stacked nanowire field effect transistor (FET) including a plurality of vertically stacked nanowire channels. Each nanowire channel is vertically separated from one another by sacrificial segment. A gate stack is on the upper surface of the semiconductor substrate. The gate stack includes a conductive element that wraps around the nanowire channels. Source/drain regions are on the upper surface of the semiconductor substrate. The source/drain regions directly contact the ends of the nanowire channel. The stacked nanowire FET further includes nanowire channel spacers that encapsulate the ends of the nanowire channel such that the source/drain regions are separated from the gate stack.
Claims20
A method of forming nanowire channel spacers in a nanowire field effect transistor (FET), the method comprising:
- forming a multi-stack semiconductor fin on an upper surface of a semiconductor substrate, the multi-stack semiconductor fin comprising a plurality of vertically stacked semiconductor material layers including plurality of nanowire channel layers, each nanowire channel layer vertically separated from one another by a sacrificial layer;
- forming a gate stack on the upper surface of the semiconductor substrate, the gate stack wrapping around the outer surfaces of the multi-stack semiconductor fin;
- forming source/drain regions on the upper surface of the semiconductor substrate, the source/drain regions contacting the multi-stack fin and being separated from the gate stack by a void that exposes portions of the sacrificial layers and the nanowire channel layers;
- etching the exposed portions of the sacrificial layers to form cavities that release opposing ends of the nanowire channel layers and form stacked nanowire channels;
- and
- filing the cavities with a spacer material that encapsulates the released ends and forms the nanowire channel spacers.
A method of forming nanowire channel spacers in a nanowire field effect transistor (FET), the method comprising:
- forming a first material layer comprising a first semiconductor material on a semiconductor substrate;
- forming a second semiconductor layer comprising a second semiconductor material on the first layer;
- forming a third semiconductor layer comprising the first semiconductor material on the second layer;
- patterning the first, second, and third semiconductor layers to form a multi-layer semiconductor fin including a channel layer portion comprising the second semiconductor material interposed between first and second sacrificial layer portions comprising the first semiconductor material;
- forming a sacrificial gate stack that wraps around the exterior surfaces of the multi-layer semiconductor fin, and forming source/drain regions on the substrate so as to define a void between the sacrificial gate stack and the source/drain regions that exposes portions of the sacrificial layer portions and the channel layer portion;
- removing the exposed portions of the sacrificial layer portions to form cavities that release ends of the channel layer portion and define a nanowire channel;
- and
- filling the cavities with a spacer material to form the nanowire channel spacers that encapsulate the ends of the channel layer portion.
A stacked nanowire field effect transistor (FET) comprising:
- a plurality of vertically stacked nanowire channels, each nanowire channel vertically separated from one another by a sacrificial segment;
- a gate stack on the upper surface of the semiconductor substrate, the gate stack including a conductive element that wraps around the nanowire channels;
- source/drain regions on the upper surface of the semiconductor substrate, the source/drain regions directly contacting ends of the nanowire channel;
- and
- nanowire channel spacers that encapsulate the ends of the nanowire channel such that the source/drain regions are separated from the gate stack.
Dependencies are inferred from the claim text.