Switching device of lcd or organic electro luminescence display
|発明の名称 （英語）||Switching device of lcd or organic electro luminescence display|
An amorphous oxide and a thin film transistor using the amorphous oxide. More specifically, an amorphous oxide having an electron carrier concentration of less than 10(18) /cm(3) and a thin film transistor using the amorphous oxide. The thin film transistor is provided with a source electrode (6), a drain electrode (5), a gate electrode (4), a gate insulating film (3) and a channel layer (2). As the channel layer (2), the amorphous oxide having an electron carrier concentration of less than 10(18)/cm(3) is used.
(C) KIPO & WIPO 2009
Is a thin film transistor (Thin Film Transistor, TFT) the gate terminal, a source terminal and a drain terminal 3 as provided with a terminal element, the film formation (deposition) on a substrate a semiconductor thin film (hole) for the movement of the electron or hole channel is used as the channel layer, by applying a voltage to the gate terminal of the current flowing in the channel layer by controlling a current between the source and drain terminals having the function of switching the active elements. Currently the most widely used as TFT is polycrystalline silicon or amorphous silicon film as a channel layer material with a liquid crystal display element Metal-Insulator-Semiconductor Field Effect Transistor(MIS-FET).
In addition, in recent years using a transparent conductive oxide polycrystalline thin film ZnO channel layer is used in the development of actively TFT (patent document 1) below. The thin film may be formed at low temperature and at the same time since it is transparent to visible light on a substrate such as a plastic plate or film (flexible) transparent TFT flexible form are possible.
However, the conventional stable amorphous phase at room temperature ZnO cannot be formed, a polycrystalline phase most ZnO since the interface between polycrystalline particles due to scattering of the electron mobility does not have to be made large. Moreover ZnO is an oxygen defect is caused to occur, generation of many carrier electrons to reduce the electrical conductivity is difficult. Because of this transistor is turned on and off of a large ratio of (ON OFF ·i′) also difficult.
In addition, patent document 2 discloses as an amorphous oxide ZnxMyInzO(x+3y/2+3z/2) (wherein, at least one element of Al M Ga and is and, the ratio x/y is in the range of z/y and 0.2-12 ratio is 0.4-1. 4 the present invention. in the range of) an amorphous oxide represented by the method has been described. However obtained in electron carrier concentration of the amorphous oxide film 1018/cm3 or more, a transparent electrode in a simple but sufficient to provide the channel layer is difficult to apply TFT was achieved. This is because the amorphous oxide film in the channel layer is made to be turned on and off ratio is sufficiently TFT could not be obtained in a normally off type TFT of and is not suitable because it has been found that the present invention.
Patent document 1: Japanese Unexamined Patent Application Publication No. 2003-298062
Patent document 2: Japanese Unexamined Patent Application Publication No. 2000-044236
1. A channel layer, a gate insulating film, gate electrode, source electrode and drain electrode of the thin film transistor,
Wherein the channel layer,
A vapor phase film forming method, a glass substrate, deposited on the plastic substrate or plastic film, In, Ga, O Zn and in which a transparent element and the amorphous oxide thin film,
Wherein the oxide of the composition, the composition of the crystallized expressed when InGaO3(ZnO) m(mis a natural number less than 6) and,
Without the addition of impurity ions,
An electron mobility of greater than 1cm2/(V · sec) at the same time as the electron carrier concentration is 1018/cm3 semi and less than,
10 Turning on and off ratio3 thin film transistor having a larger transistor characteristics and consisting of the switching element of the display or an organic EL LCD.
2. Method according to claim 1,
A gate insulating layer of the thin film transistor Al2O3, Y2O3, or HfO2 one of 1, a compound comprising at least one of at least 2 or a mixed crystal compound and using the switching element of the display or an organic EL LCD.
|参考情報 （研究プロジェクト等）||ERATO HOSONO Transparent ElectroActive Materials AREA|
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