Display device
A display device including a substrate having thin film transistors (TFT) comprising: the TFT including an oxide semiconductor film, a gate electrode and an insulating film formed between the oxide semiconductor film and the gate electrode, wherein a first aluminum oxide film and a second aluminum oxide film, which is formed on the first aluminum oxide film, are formed between the insulating film and the gate electrode, an oxygen concentration in the first aluminum oxide film is bigger than an oxygen concentration in the second aluminum oxide film.
1. A display device including a substrate having thin film transistors (TFT) in display area comprising:
the TFT including an oxide semiconductor film, a gate electrode and an insulating film formed between the oxide semiconductor film and the gate electrode,
wherein a first oxide film and a second oxide film, which is formed on the first oxide film, are formed between the insulating film and the gate electrode,
the insulating film is made of silicon oxide,
the first oxide film and the second oxide film are made of aluminum oxide, and
an oxygen concentration in the first oxide film is larger than an oxygen concentration in the second oxide film.
2. The display device according to claim 1 ,
wherein a thickness of the second oxide film is bigger than a thickness of the first oxide film.
3. The display device according to claim 1 ,
wherein a thickness of the first oxide film is 2-5 nm.
4. The display device according to claim 1 ,
wherein a thickness of the second oxide film is 5-10 nm.
5. The display device according to claim 1 ,
wherein the gate electrode is made of a metal, which has aluminum as a major substance.
6. The display device according to claim 1 ,
wherein the TFT is a top gate type TFT.
7. The display device according to claim 1 ,
wherein the insulating film is formed between the gate electrode and the oxide semiconductor film, and
the insulating film is not formed on a drain or a source of the oxide semiconductor film.