Multigate transistors with capping layers and a buffer layer comprising germanium
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsShahaji B. More, Cheng-Han Lee, Shih-Chieh Chang, Wan-Hsuan Hsieh, Chung-En Tsai, Chee-Wee Liu
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Abstract
The present disclosure provides a semiconductor structure and a method of forming the same. A semiconductor structure according to the present disclosure includes a plurality of nanostructures disposed over a substrate and a gate structure wrapping around each of the plurality of nanostructure. Each of the plurality of nanostructures includes a channel layer sandwiched between two cap layers along a direction perpendicular to the substrate.
Claims20
A semiconductor structure, comprising:
- a substrate;
- a structure extending from the substrate and comprising:
- a base portion formed from the substrate,
- a buffer layer disposed over the base portion, and
- a plurality of nanostructures disposed over the buffer layer, wherein each of the plurality of nanostructures comprises a channel layer sandwiched between two cap layers along a direction perpendicular to the substrate;
- an isolation feature disposed over the substrate and interfacing sidewalls of the base portion and sidewalls of the buffer layer;
- and
- a gate structure wrapping around each of the plurality of nanostructures,
- wherein the buffer layer comprises undoped germanium.
A semiconductor structure, comprising:
- a first source/drain feature and a second source/drain feature disposed over a substrate;
- a plurality of channel members extending between the first source/drain feature and the second source/drain feature, wherein each of the plurality of channel members comprises a semiconductor layer sandwiched between two cap layers along a direction perpendicular to the substrate;
- and
- a gate structure wrapping around each of the plurality of channel members,
- wherein the gate structure interfaces the two cap layers of each of the plurality of channel members,
- wherein the substrate comprises a buried oxide layer,
- wherein the semiconductor layer and the two cap layers comprise germanium and tin,
- wherein a first germanium content of the semiconductor layer is smaller than a second germanium content of the two cap layers.
A semiconductor structure, comprising:
- a substrate;
- a buffer layer over the substrate;
- a first source/drain feature and a second source/drain feature disposed over the substrate and partially extending into the buffer layer;
- a plurality of channel members extending between the first source/drain feature and the second source/drain feature;
- and
- a gate structure wrapping around each of the plurality of channel members,
- wherein at least one of the plurality of channel members comprises a semiconductor layer sandwiched between two cap layers along a direction perpendicular to the substrate,
- wherein the buffer layer comprises undoped germanium.
Dependencies are inferred from the claim text.