Low energy etch process for nitrogen-containing dielectric layer

US9633948B2 · kind B2 · utility

Assignees

• GlobalFoundries Inc. · KY
• ZEON CORPORATION · JP

Inventors

• Markus Brink · White Plains, US
• Robert L. Bruce · White Plains, US
• Sebastian U. Engelmann · White Plains, US
• Nicholas C. M. Fuller · Elmsford, US
• Hiroyuki Miyazoe · White Plains, US
• Masahiro Nakamura · Eastchester, US

Key dates

• Filing date: Oct 20, 2015
• Grant date: Apr 25, 2017
• Expiry date: Oct 25, 2035

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L2924/0002
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A stack that includes, from bottom to top, a nitrogen-containing dielectric layer, an interconnect level dielectric material layer, and a hard mask layer is formed on a substrate. The hard mask layer and the interconnect level dielectric material layer are patterned by an etch. Employing the patterned hard mask layer as an etch mask, the nitrogen-containing dielectric layer is patterned by a break-through anisotropic etch, which employs a fluorohydrocarbon-containing plasma to break through the nitrogen-containing dielectric layer. Fluorohydrocarbon gases used to generate the fluorohydrocarbon-containing plasma generate a carbon-rich polymer residue, which interact with the nitrogen-containing dielectric layer to form volatile compounds. Plasma energy can be decreased below 100 eV to reduce damage to physically exposed surfaces of the interconnect level dielectric material layer.