Semiconductor device and manufacturing method thereof
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsCheng-Ting Chung, Hou-Yu Chen, Ching-Wei Tsai
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Abstract
A semiconductor device includes a semiconductor layer, a gate structure, a source/drain epitaxial structure, a backside dielectric cap, and an inner spacer. The gate structure wraps around the semiconductor layer. The source/drain epitaxial structure is adjacent the gate structure and electrically connected to the semiconductor layer. The backside dielectric cap is disposed under and in direct contact with the gate structure. The inner spacer is in direct contact with the gate structure and the backside dielectric cap.
Claims20
A semiconductor device, comprising:
- a semiconductor layer;
- a gate structure wrapping around the semiconductor layer;
- a source/drain epitaxial structure adjacent the gate structure and electrically connected to the semiconductor layer;
- a backside dielectric cap disposed under and in direct contact with the gate structure;
- and
- an inner spacer in direct contact with the gate structure and the backside dielectric cap.
A semiconductor device, comprising:
- a channel;
- a gate structure surrounding the channel, wherein the gate structure has a concave bottom surface;
- inner spacers on opposite sides of the gate structure, wherein bottom surfaces of the inner spacers are lower than the concave bottom surface of the gate structure;
- and
- a source/drain epitaxial structure electrically connected to the channel.
A method of forming a semiconductor device, the method comprising:
- forming a fin structure over a substrate, wherein the fin structure comprises first semiconductor layers and second semiconductor layers alternately stacked;
- forming a dummy gate structure over the fin structure;
- removing a portion of the fin structure uncovered by the dummy gate structure;
- forming inner spacers on opposite sides of remaining portions of the first semiconductor layers;
- forming a source/drain epitaxial structure on a side of the remaining portions of the first semiconductor layers;
- replacing the dummy gate structure and the first semiconductor layers with a metal gate structure;
- removing the substrate to expose a bottom portion of the metal gate structure;
- removing the bottom portion of the metal gate structure to form a gate trench between the inner spacers;
- forming a backside dielectric cap in the gate trench;
- and
- forming a backside via under the source/drain epitaxial structure.
Dependencies are inferred from the claim text.