Process flow for dual damescene interconnect structures

US6872665B1 · kind B1 · utility

Assignee

• TEXAS INSTRUMENTS INCORPORATED · US

Inventors

• Francis G. Celii · Dallas, US
• Guoqiang Xing · Plano, US
• Andrew John McKerrow · Dallas, US
• Andrew Ralston · Richardson, US
• Zhicheng Tang · Plano, US
• Kenneth Newton · McKinney, US
• Robert J. Kraft · Tequesta, US
• Jeff West · Dallas, US

Key dates

• Filing date: Jun 22, 2000
• Grant date: Mar 29, 2005
• Expiry date: Jun 22, 2020

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76808
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A dual damascene process flow for forming interconnect lines and vias in which at least part of the via (116) is etched prior to the trench etch. A low-k material such as a thermoset organic polymer is used for the ILD (106) and IMD (110). After the at least partial via etch, a BARC (120) is deposited over the structure including in the via (116). Then, the trench (126) is patterned and etched. Although at least some of the BARC (120) material is removed during the trench etch, the bottom of the via (116) is protected.