Self-aligned airgaps with conductive lines and vias
AssigneeInternational Business Machines Corporation
InventorsBenjamin D. Briggs, Lawrence A. Clevenger, Bartlet H. Deprospo, Huai Huang, Christopher J. Penny, Michael Rizzolo
Life of this patent
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Abstract
A conductive line structure comprises a first conductive line arranged in a first dielectric layer, a second conductive line arranged in the first dielectric layer, a cap layer arranged on the first conductive line and the second conductive line, and an airgap arranged between the first conductive line and the second conductive line, the airgap defined by the first dielectric layer and the cap layer.
Claims20
A method for forming an airgap between conductive lines, the method comprising:
- forming a first conductive line in a first cavity in a first dielectric layer and forming a second conductive line in a second cavity in the first dielectric layer;
- removing a portion of the first conductive line and a portion of the second conductive line to expose a portion of the first cavity and a portion of the second cavity;
- depositing a cap layer over the first dielectric layer, the first conductive line, and the second conductive line;
- forming a second dielectric layer in the first cavity and the second cavity;
- forming a planarization layer over the cap layer and the second dielectric layer;
- removing a portion of the planarization layer to expose a portion of the cap layer;
- removing a portion of the cap layer to expose a portion of the first dielectric layer;
- removing the exposed portion of the first dielectric layer to form a third cavity;
- and
- depositing a third dielectric layer over exposed portions of the cap layer, the second dielectric layer and the third cavity.
A method for forming an airgap between conductive lines, the method comprising:
- forming a first conductive line in a first cavity in a first dielectric layer and forming a second conductive line in a second cavity in the first dielectric layer;
- removing a portion of the first conductive line and a portion of the second conductive line to expose a portion of the first cavity and a portion of the second cavity;
- depositing a cap layer over the first dielectric layer, the first conductive line, and the second conductive line;
- forming a second dielectric layer in the first cavity and the second cavity;
- forming a sacrificial cap on the cap layer and the second dielectric layer;
- forming a hardmask on the sacrificial cap;
- forming a planarization layer over the hardmask;
- removing a portion of the planarization layer, and the hardmask to expose a portion of the sacrificial cap;
- removing the planarization layer to expose the hardmask;
- removing exposed portions of the sacrificial cap to expose portions of the second dielectric layer and the cap layer;
- removing a portion of the cap layer to expose a portion of the first dielectric layer;
- removing the exposed portion of the first dielectric layer to form a third cavity;
- and
- depositing a third dielectric layer over exposed portions of the cap layer, the second dielectric layer and the third cavity.
A conductive line structure comprising:
- a first conductive line arranged in a first dielectric layer;
- a second conductive line arranged in the first dielectric layer;
- a cap layer arranged on the first conductive line and the second conductive line;
- and
- an airgap arranged between the first conductive line and the second conductive line, the airgap defined by the first dielectric layer and the cap layer.
Dependencies are inferred from the claim text.