Composition
The FET can be constructed from a number of semiconductors, silicon being by far the most common. Most FETs are made with conventional bulk semiconductor processing techniques, using a single crystal semiconductor wafer as the active region, or channel.
Among the more unusual body materials are amorphous silicon, polycrystalline silicon or other amorphous semiconductors in thin-film transistors or organic field effect transistors that are based on organic semiconductors; often, OFET gate insulators and electrodes are made of organic materials, as well. Such FETs are manufactured using variety of materials such as silicon carbide(SiC), gallium arsenide(GaAs), gallium nitride(GaN), and indium gallium arsenide(InGaAs). In June 2011, IBM announced that it had successfully used graphene-based FETs in an integrated circuit. These transistors are capable of a 100 GHz cutoff frequency, much higher than standard silicon FETs.
Read more about this topic: Field-effect Transistor
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