Synchronized radio frequency pulsing for plasma etching

US8962488B2 · kind B2 · utility

Assignee

• Applied Materials, Inc. · US

Inventors

• Bryan Liao · Saratoga, US
• Katsumasa Kawasaki · Los Gatos, US
• Yashaswini B. Pattar · Palo Alto, US
• Sergio Fukuda Shoji · San Jose, US
• Duy D. Nguyen · Milpitas, US
• Kartik Ramaswamy · San Jose, US
• Ankur Agarwal · Mountain View, US
• Phillip Stout · Santa Clara, US
• Shahid Rauf · Pleasanton, US

Key dates

• Filing date: Mar 25, 2013
• Grant date: Feb 24, 2015
• Expiry date: Mar 25, 2033

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/31116
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

Methods for processing a substrate are provided herein. In some embodiments, a method of etching a dielectric layer includes generating a plasma by pulsing a first RF source signal having a first duty cycle; applying a second RF bias signal having a second duty cycle to the plasma; applying a third RF bias signal having a third duty cycle to the plasma, wherein the first, second, and third signals are synchronized; adjusting a phase variance between the first RF source signal and at least one of the second or third RF bias signals to control at least one of plasma ion density non-uniformity in the plasma or charge build-up on the dielectric layer; and etching the dielectric layer with the plasma.