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US 11,961,891 B2Granted
Structure for metal gate electrode and method of fabrication
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsRu-Shang Hsiao, Ching-Hwanq Su, Pohan Kung, Ying Hsin Lu, I-Shan Huang
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Abstract
A semiconductor device includes a channel component of a transistor and a gate component disposed over the channel component. The gate component includes: a dielectric layer, a first work function metal layer disposed over the dielectric layer, a fill-metal layer disposed over the first work function metal layer, and a second work function metal layer disposed over the fill-metal layer.
Claims20
A method, comprising:
- forming a gate dielectric layer;
- depositing a first work function metal layer over the gate dielectric layer;
- depositing a fill-metal layer over the first work function metal layer, wherein the fill-metal layer defines a concave recess;
- depositing a second work function metal layer in the concave recess;
- etching the first work function metal layer, the fill-metal layer, and the second work function metal layer in a manner such that a plurality of segments of the fill-metal layer protrude above the first work function metal layer and the second work function metal layer after the etching;
- after the etching, forming a dielectric material over the first work function metal layer, the fill-metal layer, and the second work function metal layer;
- etching an opening through the dielectric material, wherein the opening exposes upper surfaces and side surfaces of a plurality of segments of the fill-metal layer;
- and
- filling the opening with a conductive gate contact, wherein the plurality of segments of the fill-metal layer protrudes vertically into the conductive gate contact.
6 more elements
A method, comprising:
- forming a gate dielectric layer;
- forming a first work function metal layer over the gate dielectric layer;
- forming a fill-metal layer over the first work function metal layer;
- forming a second work function metal layer over the fill-metal layer;
- performing an etch-back process on the first work function metal layer, the fill-metal layer, and the second work function metal layer, wherein after the etch-back process has been performed, a first portion of the fill-metal layer protrude vertically over the first work function metal layer and the second work function metal layer;
- forming, after the performing of the etch-back process, a dielectric material over the first work function metal layer, the fill-metal layer, and the second work function metal layer, wherein the dielectric material wraps around the first portion of the fill-metal layer;
- etching the dielectric material, thereby forming an opening that exposes at least side surfaces of the first portion of the fill-metal layer;
- and
- filling the opening with a conductive gate contact, wherein the first portion of the fill-metal layer is at least partially wrapped around by the conductive gate contact.
6 more elements
A method, comprising:
- forming a gate dielectric layer;
- depositing a first work function metal layer over the gate dielectric layer;
- depositing a fill-metal layer over the first work function metal layer, wherein the fill-metal layer defines a concave recess;
- depositing a second work function metal layer in the concave recess;
- etching the first work function metal layer, the fill-metal layer, and the second work function metal layer, wherein the fill-metal layer is etched at a first rate lower than that of the first work function metal layer and the second work function metal layer;
- after the etching of the first work function metal layer, the fill-metal layer, and the second work function metal layer, forming a sacrificial layer over the first work function metal layer, the fill-metal layer, and the second work function metal layer, wherein a segment of the fill-metal layer protrudes vertically into the sacrificial layer;
- etching the sacrificial layer, thereby forming an opening in the sacrificial layer that exposes side surfaces of the segment of the fill-metal layer;
- and
- filling the opening with a conductive gate contact, wherein the segment of the fill-metal layer protrudes vertically into the conductive gate contact.
6 more elements
Dependencies are inferred from the claim text.