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ASHUTOSH MISRA, Air Liquide Electronics Chemicals & Services,Inc., Dallas, TX, USA
HERVE DULPHY AND ERIC DUCHATEAU, Air Liquide Electronics, Labielle, S.A., Pont De Claix, France

ABSTRACT

Conventional methods of qualifying liquid chemical distribution systems utilize expensive process chemicals which are not always efficient in leaching out metallic contamination. This impacts both the cost and the time associated with a qualification process. We propose a new method of accelerated cleanup of PFA distribution systems using high purity dilute hydrofluoric acid and deionized water. This procedure was first characterized in lab scale experiments where it demonstrated superior metal leaching ability as well as subsequent rinsing of all fluoride from the system using a combination of static and dynamic leach/rinse cycles. Such a procedure results in significant reduction in qualification time, costs and waste generation. The proposed method was subsequently implemented on a full scale commercial liquid chemical distribution system at a semiconductor manufacturing facility.