Silicon oxide recess etch

US8748322B1 · kind B1 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Nancy Fung · Sunnyvale, US
• David T. Or · Santa Clara, US
• Qingjun Zhou · Sunnyvale, US
• Lina Zhu · San Jose, US
• Jeremiah T. Pender · San Jose, US
• Srinivas D. Nemani · Sunnyvale, US
• Sean S. Kang · San Ramon, US
• Sergey G. Belostotskiy · Santa Clara, US
• Chinh Dinh · San Jose, US

Key dates

• Filing date: Jul 16, 2013
• Grant date: Jun 10, 2014
• Expiry date: Jul 16, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76229
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of etching silicon oxide from a trench is described which allows more homogeneous etch rates across a varying pattern on a patterned substrate. The method also provides a more rectilinear profile following the etch process. Methods include a sequential exposure of gapfill silicon oxide. The gapfill silicon oxide is exposed to a local plasma treatment prior to a remote-plasma dry etch which may produce salt by-product on the surface. The local plasma treatment has been found to condition the gapfill silicon oxide such that the etch process proceeds at a more even rate within each trench and across multiple trenches. The salt by-product may be removed by raising the temperature in a subsequent sublimation step.