Bubble and foam solutions using a completely immersed air-free feedback flow control valve

US9617652B2 · kind B2 · utility

Assignee

• Lam Research Corporation · US

Inventors

• Richard Abraham · Sherwood, US
• Robert Rash · Portland, US
• David W. Porter · Tulsa, US
• Steven T. Mayer · Lake Oswego, US
• John Floyd Ostrowski · Hillsboro, US

Key dates

• Filing date: Dec 10, 2013
• Grant date: Apr 11, 2017
• Expiry date: Jul 25, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C25D17/008
• WIPO field: Surface technology, coating
• WIPO sector: Chemistry

Abstract

The embodiments disclosed herein relate to methods and apparatus for promoting bubble-free circulation of processing fluids in a recirculation system. Certain disclosed techniques involve passive, mechanical valve designs that promote variable resistance to flow in a drain. Other techniques involve automated flow control schemes that utilize feedback from flow meters, level sensors, etc. to achieve a balanced and bubble-free flow. The disclosed embodiments greatly reduce the incorporation of gas into a processing fluid, in particular as the processing fluid returns from a processing cell to a reservoir.