Apparatus and method for wet cleaning

US6584989B2 · kind B2 · utility

Assignee

• International Business Machines Corporation · US

Inventors

• Charles J. Taft · Wappingers Falls, US
• Kenneth McCullough · Fishkill, US
• George F. Ouimet · Millbrook, US
• David L. Rath · Stormville, US
• Robert W. Zigner, Jr. · Hyde Park, US

Key dates

• Filing date: Apr 17, 2001
• Grant date: Jul 1, 2003
• Expiry date: Sep 5, 2021

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S134/902
• WIPO field: Control
• WIPO sector: Instruments

Abstract

An apparatus and method is described for cleaning semiconductor wafers using a dilute aqueous solution including at least 80% deionized water, sulfuric acid, an oxidant such as hydrogen peroxide, and a small amount of hydrofluoric acid (HF), preferably in the range of about 5 ppm to about 12 ppm. The automated system mixes the water, sulfuric acid, hydrogen peroxide, and HF to form a cleaning solution having a target HF concentration within the preferred range, for example at 8 ppm. Subsequently, the system maintains the HF concentration at least within about 0.5 ppm to about 1 ppm of the target HF concentration. Thus the system allows effective and predictable cleaning of semiconductor wafers while minimizing damage to metal features, and minimizing cost and waste disposal impacts.