Amorphous oxide and thin film transistor
|Posted date||May 28, 2012|
|Country||United States of America|
|Date of filing||Apr 29, 2011|
|Gazette Date||Aug 18, 2011|
|Gazette Date||Apr 17, 2018|
|International application number||JP2005003273|
|International publication number||WO2005088726|
|Date of international filing||Feb 28, 2005|
|Date of international publication||Sep 22, 2005|
|Title||Amorphous oxide and thin film transistor|
The present invention relates to an amorphous oxide and a thin film transistor using the amorphous oxide.
In particular, the present invention provides an amorphous oxide having an electron carrier concentration less than 1018/cm3, and a thin film transistor using such an amorphous oxide.
In a thin film transistor having a source electrode 6, a drain electrode 5, a gate electrode 4, a gate insulating film 3, and a channel layer 2, an amorphous oxide having an electron carrier concentration less than 1018/cm3 is used in the channel layer 2.
|Scope of claims||
1. A method of forming a field effect thin film transistor device which is used as a normally-OFF type, comprising: providing a drain electrode;
providing a source electrode;
sputter depositing a channel layer which is contacting with the drain electrode and the source electrode, the channel layer being comprised of a transparent and amorphous indium-gallium-zinc oxide film,
wherein the sputtering deposition is performed in an oxygen-partial-pressure-controlled atmosphere at room temperature without adding impurity ions to the channel layer to increase electrical resistance, and using a polycrystalline sinter represented by InGaO3(ZnO)m (wherein m is a natural number less than 6) as a target material,
whereby forming the channel layer in which an atomic ratio In:Ga:Zn is 1:1:m (wherein m is a natural number less than 6) having an electron carrier concentration less than 1016/cm3 determined by Hall-effect measurement and an electron mobility of 1 cm2/(V.sec) or more at room temperature;
providing a gate electrode; and
providing a gate insulating film positioned between the gate electrode and the channel.
2. The method of forming a field effect thin film transistor according to claim 1, wherein the substrate is one of a glass plate, a plastic plate or a plastic film.
3. The method of forming a field effect thin film transistor according to claim 1, further comprising a step of heating the indium-gallium-zinc oxide film in a reducing atmosphere to increase the electron carrier concentration after the film formation.
4. The method of forming a field effect thin film transistor according to claim 1, the transistor is a switching element of LCDs or organic EL displays.
|IPC(International Patent Classification)||
|Reference ( R and D project )||ERATO HOSONO Transparent ElectroActive Materials AREA|
Contact Information for " Amorphous oxide and thin film transistor "
- Japan Science and Technology Agency Department of Intellectual Property Management
- URL: http://www.jst.go.jp/chizai/
- Address: 5-3, Yonbancho, Chiyoda-ku, Tokyo, Japan , 102-8666
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