Bottom barrier free interconnects without voids

US11164815B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Kenneth Chun Kuen Cheng · Sha Tin, CN
• Koichi Motoyama · Clifton Park, US
• Kisik Choi · Hopewell Junction, US
• Cornelius Brown Peethala · Slingerlands, US
• Hosadurga Shobha · Armonk, US
• Joe Lee · Albany, US

Key dates

• Filing date: Sep 28, 2019
• Grant date: Nov 2, 2021
• Expiry date: Sep 28, 2039

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L23/5283
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Techniques to enable bottom barrier free interconnects without voids. In one aspect, a method of forming interconnects includes: forming metal lines embedded in a dielectric; depositing a sacrificial dielectric over the metal lines; patterning vias and trenches in the sacrificial dielectric down to the metal lines, with the trenches positioned over the vias; lining the vias and trenches with a barrier layer; depositing a conductor into the vias and trenches over the barrier layer to form the interconnects; forming a selective capping layer on the interconnects; removing the sacrificial dielectric in its entirety; and depositing an interlayer dielectric (ILD) to replace the sacrificial dielectric. An interconnect structure is also provided.