Bilayer trench first hardmask structure and process for reduced defectivity
AssigneeInternational Business Machines Corporation
InventorsHakeem B. S. Akinmade-Yusuff, Samuel Sung Shik Choi, Edward R. Engbrecht, John A. Fitzsimmons
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Abstract
A method and structure for transferring a lithographic pattern into a substrate includes forming a dielectric hardmask layer over a dielectric substrate. A metal hardmask layer is formed over the dielectric hardmask layer. A protective capping hardmask layer or capping film is formed over the metal hardmask layer, and a lithographic structure for pattern transfer is formed over the capping layer. A pattern is transferred into the dielectric substrate using the defined lithographic structure. The capping hardmask layer can be removed during subsequent processing.
Claims11
A method for forming a trench pattern in a structure, comprising:
- forming a dielectric hardmask layer over a dielectric substrate, said dielectric substrate comprising a stack of, from bottom to top, a patterned dielectric substrate layer and a dielectric layer;
- forming a metal hardmask layer over the dielectric hardmask layer;
- forming a capping hardmask layer over the metal hardmask layer, wherein a stress in the capping hardmask layer is configured to counter balance a stress in the metal hardmask layer;
- forming at least one organic layer over the capping hardmask layer;
- forming an initial trench pattern through the at least one organic layer, the capping hardmask layer, and the metal hardmask layer and into the dielectric hardmask layer;
- removing the at least one organic layer;
- and
- extending the initial trench pattern into the dielectric layer of the dielectric substrate to form a trench pattern, wherein the capping hardmask layer is present during an initial stage of said forming the trench pattern to protect the metal hardmask layer from erosion.
Dependencies are inferred from the claim text.