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US 12,772,825 B2Granted
Backside dielectric cap
AssigneeInternational Business Machines Corporation
InventorsChen Zhang, Ruilong Xie, Debarghya Sarkar, Junli Wang
Life of this patent
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Abstract
A semiconductor structure is provided that includes a backside dielectric cap which seals the gate structure thus preventing gate structure exposure during backside processing. The presence of the backside dielectric cap helps to mitigate gate to direct backside source/drain contact shorts. The backside dielectric cap is formed during frontside processing.
Claims19
A semiconductor structure comprising:
- a transistor comprising a first source/drain region located on a first side of a gate structure and a second source/drain region located on a second side of the gate structure;
- a backside dielectric cap in direct physical contact with a surface of the gate structure;
- a backside source/drain contact structure directly contacting a surface of the first source/drain region of the transistor;
- and
- a shallow trench isolation structure located beneath, and in contact with, the backside dielectric cap, wherein the backside dielectric cap has a sidewall that is vertically aligned to a sidewall of the shallow trench isolation structure.
2 more elements
A method of forming a semiconductor structure, the method comprising:
- forming a shallow trench isolation structure in a semiconductor substrate and adjacent to a mesa portion of a semiconductor substrate, wherein a semiconductor channel material structure is located on the mesa portion of the semiconductor substrate;
- forming a dielectric layer on the shallow trench isolation structure and on top of the semiconductor channel material structure;
- selectively removing the dielectric layer that is located on top of the semiconductor channel material structure, while maintaining the dielectric layer on the shallow trench isolation structure;
- forming a sacrificial gate structure on the semiconductor channel material structure;
- forming a backside source/drain contact placeholder structure in the semiconductor substrate and on each side of the sacrificial gate structure;
- forming a source/drain region on each of the backside source/drain contact placeholder structures;
- replacing the sacrificial gate structure with a gate structure;
- removing the semiconductor substrate to physically expose each of the backside source/drain contact placeholder structures;
- forming a backside interlayer dielectric layer embedding each of the backside source/drain contact placeholder structures;
- and
- replacing at least one of the backside source/drain contact placeholder structures with a backside source/drain contact structure.
8 more elements
Dependencies are inferred from the claim text.