b626bc89_tsugi_JP___Patent_applications__Description
[Patent application number] 20130045568 [Published] 02-21-2013 [Description] 
SEMICONDUCTOR DEVICE AND MANUFACTURING METHOD THEREOF - Electric characteristics and reliability of a thin film transistor are impaired by diffusion of an impurity element into a channel region. The present invention provides a thin film transistor in which aluminum atoms are unlikely to be diffused to an oxide semiconductor layer. A thin film transistor including an oxide semiconductor layer including indium, gallium, and zinc includes source or drain electrode layers in which first conductive, layers including aluminum as a main component and second conductive layers including a high-melting-point metal material are stacked. An oxide semiconductor layer
Kengo Akimoto, Atsugi JP - Patent applications