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A thin-film transistor (TFT) is a special kind of field-effect transistor made by depositing thin films of an active semiconductor layer as well as the dielectric layer and metallic contacts over a supporting (but non-conducting) substrate. A common substrate is glass, because the primary application of TFTs is in liquid-crystal displays. This differs from the conventional transistor, where the semiconductor material typically ''is'' the substrate, such as a silicon wafer. == Manufacture== TFTs can be made using a wide variety of semiconductor materials. A common material is silicon. The characteristics of a silicon-based TFT depend on the silicon's crystalline state; that is, the semiconductor layer can be either amorphous silicon, microcrystalline silicon,〔 or it can be annealed into polysilicon. Other materials which have been used as semiconductors in TFTs include compound semiconductors such as cadmium selenide, or metal oxides such as zinc oxide.〔 TFTs have also been made using organic materials, referred to as organic field-effect transistors or OTFTs. By using transparent semiconductors and transparent electrodes, such as indium tin oxide (ITO), some TFT devices can be made completely transparent. Such transparent TFTs (TTFTs) can be used for construction of video display panels. Because conventional substrates cannot withstand high annealing temperatures, the deposition process must be completed under relatively low temperatures. Chemical vapor deposition and physical vapor deposition (usually sputtering) are applied. The first solution-processed TTFTs, based on zinc oxide, were reported in 2003 by researchers at Oregon State University.〔Wager, John. (OSU Engineers Create World's First Transparent Transistor ). College of Engineering, Oregon State University, Corvallis, OR: OSU News & Communication, 2003. 29 July 2007.〕 The Portuguese laboratory CENIMAT at the Universidade Nova de Lisboa has produced the world’s first completely transparent TFT at room temperature. CENIMAT also developed the first paper transistor, which may lead to applications such as magazines and journal pages with moving images. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Thin-film transistor」の詳細全文を読む スポンサード リンク
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