Semiconductor structures with reduced parasitic capacitance
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsBwo-Ning CHEN, Chang-Miao LIU
Life of this patent
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Abstract
In an embodiment, an exemplary method includes forming a dielectric structure over a substrate, the dielectric structure includes a first portion disposed between a first source/drain feature and a second source/drain feature adjacent to the first source/drain feature and a second portion over the first portion. The exemplary method also includes replacing a part of the first portion of the dielectric structure with a dielectric feature having a different composition than the dielectric structure, and replacing a part of the second portion of the dielectric structure with a source/drain contact electrically coupled to both the first and second source/drain features.
Claims20
A method, comprising:
- receiving a structure comprising:
- a first source/drain feature over a source/drain region of a first fin-shaped active region protruding from a substrate,
- a second source/drain feature over a source/drain region of a second fin-shaped active region,
- an isolation feature disposed between the first fin-shaped active region and the second fin-shaped active region, and
- a multi-layer dielectric structure over the isolation feature and the first and second source/drain features;
- forming an opening extending into the multi-layer dielectric structure, wherein a lower portion of the opening exposes sidewall surfaces of the first and second source/drain features;
- forming a dielectric feature in the lower portion of the opening;
- and
- forming a source/drain contact on the dielectric feature.
A method, comprising:
- forming a dielectric structure over a substrate, the dielectric structure comprising:
- a first portion disposed between a first source/drain feature and a second source/drain feature adjacent to the first source/drain feature, and
- a second portion over the first portion;
- replacing a part of the first portion of the dielectric structure with a dielectric feature having a different composition than the dielectric structure;
- and
- replacing a part of the second portion of the dielectric structure with a source/drain contact electrically coupled to both the first and second source/drain features.
A semiconductor structure, comprising:
- a first transistor comprising:
- a first gate structure over a first channel region, and
- a first source/drain feature coupled to the first channel region;
- a second transistor comprising:
- a second gate structure over a second channel region, and
- a second source/drain feature coupled to the second channel region;
- a first dielectric structure extending from a lower portion of the first source/drain feature to a lower portion of the second source/drain feature;
- a second dielectric structure over the first dielectric structure and having a different composition than the first dielectric structure;
- and
- a source/drain contact electrically coupled to the first and second source/drain features and on the second dielectric structure.
Dependencies are inferred from the claim text.