Perfluoroelastomers are a type of synthetic rubber having even greater heat and chemical resistance than the fluoroelastomers. Perfluoroelastomers are widely used as seals on semiconductor wafer processing equipment. This type of rubber can be used in extreme conditions up to temperatures around 300 degree celcius or even higher under special compounding. The basic disadvantages of this rubber are difficult processing, very high cost, poor physical properties at high temperature, and their high glass transition temperatures which limit their use at low temperatures. Most materials cannot be used below zero degree celsius, and even at normal temperatures their creep properties are likely to be poor.

The commercial application of perfluoroelastomer started in the 1960s. From this early beginning the use of perfluoroelastomers has increased steadily over the years. Today Perfluoroelastomer seals are manufactured by a number of companies worldwide.
Properties of Perfluoroelastomers (FFKM)

• This rubber has extraordinary resistance to harsh chemicals and heat.
• They are enable to withstand virtually any process media, including reactive plasmas, at temperatures as high as 327°C.
• In plasma and chemical vapor deposition applications, perfluoroelastomers can withstand long term exposure in etching, stripping and cleaning processes.
• In wet chemical operations, swelling due to prolonged chemical exposure and poor elastic recovery are frequent causes of seal failure. These inadequacies are eliminated in perfluoroelastomers.
• The reliability of seals made from perfluoroelastomers leads to reduced wafer yield losses and lowered frequency of maintenance and operations disruptions.