Selective etching of silicon nitride

US8252696B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Xinliang Lu · Fremont, US
• Haichun Yang · Santa Clara, US
• Zhenbin Ge · Campbell, US
• Nan Lu · Santa Clara, US
• David T. Or · Santa Clara, US
• Chien-Teh Kao · Sunnyvale, US
• Mei Chang · San Jose, US

Key dates

• Filing date: Oct 7, 2008
• Grant date: Aug 28, 2012
• Expiry date: May 1, 2031

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31116
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

Methods for etching dielectric layers comprising silicon and nitrogen are provided herein. In some embodiments, such methods may include providing a substrate having a dielectric layer comprising silicon and nitrogen disposed thereon, forming reactive species from a process gas comprising hydrogen (H2) and nitrogen trifluoride (NF3) using a remote plasma; and etching the dielectric layer using the reactive species. In some embodiments, an oxide layer is disposed adjacent to the dielectric layer. In some embodiments, the flow rate ratio of the process gas can be adjusted such that an etch selectivity of the dielectric layer to at least one of the oxide layer or the substrate is between about 0.8 to about 4.