Spacer to prevent source-drain contact encroachment
AssigneeGlobalfoundries Inc.
InventorsYong M. Lee, Yue Hu, Wen-Pin Peng
Life of this patent
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Abstract
Aspects of the present invention relate to approaches for preventing contact encroachment in a semiconductor device. A first portion of a contact trench can be etched partway to a source-drain region of the semiconductor device. A dielectric liner can be deposited in this trench. A second etch can be performed on the lined trench to etch the contact trench channel the remainder of the way to the source-drain region. This leaves a portion of the dielectric liner remaining in the trench (e.g., covering the vertical walls of the trench) after the second etch.
Claims20
A method for preventing contact encroachment in a semiconductor device, comprising:
- etching a first portion of a contact trench to a source-drain region of the semiconductor device;
- depositing a dielectric liner in the trench;
- and
- etching a remainder of the contact trench channel to the source-drain region,
- wherein at least a portion of the dielectric liner deposited on horizontal walls of the trench remains after the remainder of the contact trench has been formed.
A method for forming a semiconductor device, comprising:
- forming a source-drain region, a replacement metal gate, and an inter-layer dielectric layer on a substrate;
- forming a stress nitride encapsulation layer over the replacement metal gate and the inter-layer dielectric layer;
- detecting a susceptible region for a potential defect in the semiconductor device between the metal gate and the source-drain region;
- etching a first portion of a contact trench to a source-drain region of the semiconductor device, the first portion of the contact trench extending to a depth that is below the susceptible region and above the source-drain region;
- depositing a dielectric liner in the trench, wherein a portion of the dielectric liner overlays the susceptible region;
- and
- etching a remainder of the contact trench channel to the source-drain region while leaving the portion of the dielectric liner that overlays the susceptible region.
A semiconductor device, formed via a process, comprising:
- forming a source-drain region, a replacement metal gate, and an inter-layer dielectric layer on a substrate;
- forming a stress nitride encapsulation layer over the replacement metal gate and the inter-layer dielectric layer;
- detecting a susceptible region for a potential defect in the semiconductor device between the metal gate and the source-drain region;
- etching a first portion of a contact trench to a source-drain region of the semiconductor device, the first portion of the contact trench extending to a depth that is below the susceptible region and above the source-drain region;
- depositing a dielectric liner in the trench, wherein a portion of the dielectric liner overlays the susceptible region;
- and
- etching a remainder of the contact trench channel to the source-drain region while leaving the portion of the dielectric liner that overlays the susceptible region.
Dependencies are inferred from the claim text.