Field effect transistor

The field-effect transistor (FET) is a transistor that relies on an electric field to control the shape and hence the conductivity of a "channel" in a semiconductor material. FETs are sometimes used as voltage-controlled resistors.

Related Topics:
Transistor - Electric field - Conductivity - Semiconductor - Resistor

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Most FETs are made with conventional bulk semiconductor processing techniques, using the single crystal semiconductor wafer as the active region, or channel. The channel region of TFTs (thin-film transistors), on the other hand, is a thin film that is deposited onto a substrate (often glass, since the primary application of TFTs is in liquid crystal displays). For more on TFTs, see thin-film transistor; the remainder of this article deals with the transistors most commonly used in integrated circuits. In biology, voltage-gated ion channels work in a similar way.

Related Topics:
Semiconductor processing techniques - Single crystal - Semiconductor - Thin-film transistor - Deposited - Glass - Liquid crystal display - Integrated circuit - Voltage-gated ion channel

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The terminals in FET are called gate, drain and source. (Compare these to the terminology used for BJTs: base, collector and emitter.) The voltage applied between the gate and source terminals modulates the current between source and drain.

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