Because of the aggressive chemicals in use and the need to exclude microcontaminants, the semiconductor industry offers some real challenges. Seals used in the production of integrated circuits (ICs) must withstand harsh fluids while resisting extraction. Several companies have developed fully-fluorinated compounds for use in wet chemical, dry chemical, vacuum, and plasma applications. These companies include DuPont (Kalrez® Ultrapure); Greene, Tweed (Chemraz®); and International Seal-FNGP (Aegis®).

For example, each of the Aegis “SC” perfluoroelastomers is environment-specific. SC1001 is a low compression set compound intended primarily for wet chemical applications. SC1011 is used mainly in dry process, vacuum, and plasma environments. SC1090 is the cleanest grade of Aegis and is intended for both wet chemical and plasma projects. SC1070 is a high temperature formulation (viable up to 572° F, 300° C) intended for low-pressure chemical vapor deposition and furnace applications. With high temperature resistance comparable to SC1070, SC1071 can handle aggressive plasma.

Regardless of the manufacturer, it’s important to note that black, carbon-filled compounds are most susceptible to having parts of their chemical make-up extracted by system fluids. This “leaching” of the material leads to seal shrinkage and may result in seal failure. For this reason, white or clear compounds making use of other fillers (such as barium sulfate or PTFE) are typically used in applications where shrinkage is a big concern. Fluorocarbons (such as Viton®), fluorosilicones, and ethylene propylene are also used in semiconductor production. Fluorosilicones and EPDM are seeing less use, however, because they do not function as cleanly as either perfluoroelastomers or fluorocarbons.

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