Semiconductor device and method of forming the same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsBo-Feng Young, Sai-Hooi Yeong, Chi-On Chui
Life of this patent
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Abstract
Provided are a semiconductor device and a method of forming the same. The semiconductor device includes a substrate, a plurality of semiconductor nanosheets, a bottom dielectric layer, and a gate stack. The substrate includes at least one fin. The plurality of semiconductor nanosheets are stacked on the at least one fin. The bottom dielectric layer is vertically disposed between the at least one fin and the plurality of semiconductor nanosheets. The gate stack wraps the plurality of semiconductor nanosheets. An area of the gate stack projected on a top surface of the substrate is within an area of the bottom dielectric layer projected on the top surface of the substrate.
Claims20
A semiconductor device, comprising:
- a substrate;
- a buffer layer disposed over the substrate and extending along a first direction;
- a plurality of nanostructures stacked over the buffer layer;
- and
- a bottom dielectric layer disposed between the substrate and the buffer layer, wherein the bottom dielectric layer is separated from the plurality of nanostructures by the buffer layer.
A method of forming a semiconductor device, comprising:
- forming a bottom semiconductor layer over the substrate, wherein the bottom semiconductor layer extends along a first direction;
- forming a buffer layer over the bottom semiconductor layer, wherein the buffer layer extends along the first direction;
- forming a nanostructure stack over the buffer layer;
- forming a dummy gate stack across the nanostructure stack and extending along a second direction;
- forming source/drain (S/D) regions at opposite sides of the dummy gate stack and connected to the nanostructure stack;
- removing the dummy gate stack;
- performing a first etching process to remove a portion of the bottom semiconductor layer under the nanostructure stack, so as to form a first gap in the bottom semiconductor layer;
- and
- forming a bottom dielectric layer in the first gap, wherein the bottom dielectric layer is embedded in the bottom semiconductor layer.
A semiconductor device, comprising:
- a substrate;
- a bottom layer over the substrate and extending along a first direction, wherein the bottom layer comprises a bottom dielectric layer embedded in a bottom semiconductor layer;
- a plurality of nanostructures stacked over the bottom dielectric layer;
- a gate stack wrapping the plurality of nanostructures and extending along a second direction different from the first direction;
- and
- source/drain (S/D) regions disposed at opposite sides of the gate stack and connected to the plurality of nanostructures in the first direction, wherein a projection of the S/D regions overlaps with a projection of the bottom dielectric layer.
Dependencies are inferred from the claim text.