Fully aligned via for interconnect

US11495538B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Ruilong Xie · Niskayuna, US
• Christopher J. Waskiewicz · Rexford, US
• Chih-Chao Yang · Glenmont, US
• Lawrence A. Clevenger · Saratoga Springs, US
• Ashim Dutta · Clifton Park, US

Key dates

• Filing date: Jul 18, 2020
• Grant date: Nov 8, 2022
• Expiry date: Jul 18, 2040

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L23/53257
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A fully aligned via interconnect structure and techniques for formation thereof using subtractive metal patterning are provided. In one aspect, an interconnect structure includes: metal lines Mx−1; metal lines Mx disposed over the metal lines Mx−1; and at least one via Vx−1 fully aligned between the metal lines Mx−1 and the metal lines Mx, wherein a top surface of at least one of the metal lines Mx−1 has a stepped profile. In another aspect, another interconnect structure includes: metal lines Mx−1; metal lines Mx disposed over the metal lines Mx−1; at least one via Vx−1 fully aligned between the metal lines Mx−1 and the metal lines Mx; and sidewall spacers alongside the metal lines Mx. A method of forming an interconnect structure is also provided.