Method to reduce charge buildup during high aspect ratio contact etch

US7985692B2 · kind B2 · utility

Assignee

• Micron Technology, Inc. · US

Inventors

• Gurtej S. Sandhu · Boise, US
• Max Hineman · Boise, US
• Daniel A. Steckert · Boise, US
• Jingyi Bai · San Jose, US
• Shane J. Trapp · Boise, US
• Tony Schrock · Boise, US

Key dates

• Filing date: Jan 23, 2008
• Grant date: Jul 26, 2011
• Expiry date: Jan 24, 2030

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S438/906
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of high aspect ratio contact etching a substantially vertical contact hole in an oxide layer using a hard photoresist mask is described. The oxide layer is deposited on an underlying substrate. A plasma etching gas is formed from a carbon source gas. Dopants are mixed into the gas. The doped plasma etching gas etches a substantially vertical contact hole through the oxide layer by doping carbon chain polymers formed along the sidewalls of the contact holes during the etching process into a conductive state. The conductive state of the carbon chain polymers reduces the charge buildup along sidewalls to prevent twisting of the contact holes by bleeding off the charge and ensuring proper alignment with active area landing regions. The etching stops at the underlying substrate.