Anisotropic gap etch

US9502258B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Jun Xue · San Jose, US
• Ching-Mei Hsu · Stanford, US
• Zihui Li · Santa Clara, US
• Ludovic Godet · Sunnyvale, US
• Anchuan Wang · San Jose, US
• Nitin K. Ingle · San Jose, US

Key dates

• Filing date: Dec 23, 2014
• Grant date: Nov 22, 2016
• Expiry date: Dec 23, 2034

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/3223
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method of anisotropically dry-etching exposed substrate material on a patterned substrate is described. The patterned substrate has a gap formed in a single material made from, for example, a silicon-containing material or a metal-containing material. The method includes directionally ion-implanting the patterned structure to implant the bottom of the gap without implanting substantially the walls of the gap. Subsequently, a remote plasma is formed using a fluorine-containing precursor to etch the patterned substrate such that either (1) the walls are selectively etched relative to the floor of the gap, or (2) the floor is selectively etched relative to the walls of the gap. Without ion implantation, the etch operation would be isotropic owing to the remote nature of the plasma excitation during the etch process.