Forming chamferless vias using thermally decomposable porefiller

US9685366B1 · kind B1 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Benjamin D. Briggs · Cohoes, US
• Lawrence A. Clevenger · Saratoga Springs, US
• Bartlet H. DeProspo · Middletown, US
• Huai Huang · Clifton Park, US
• Christopher J. Penny · Saratoga Springs, US
• Michael Rizzolo · Delmar, US

Key dates

• Filing date: Apr 21, 2016
• Grant date: Jun 20, 2017
• Expiry date: Apr 21, 2036

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31144
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for forming chamferless vias comprises receiving a substrate stack comprising a hard mask layer, a porous dielectric layer underlying the hard mask layer, a cap layer underlying the dielectric layer, and a conductive layer underlying the cap layer. The hard mask layer is opened to reveal a portion of the dielectric layer. A plurality of vias are opened to extend through the dielectric layer and the cap layer. A pore filling material comprising a thermally decomposable polymer is deposited into the vias. The pore filling material in the vias is hardened and driven into the pores of the dielectric layer adjacent to the vias by an annealing process. The hard mask layer is removed. A trench is patterned and etched coincident with the vias. A dissipation process is conducted to remove the pore filling material.