Display device
The purpose of the present invention is to form both LTPS TFT and semiconductor TFT in a same substrate. The feature of the display device to realize the above purpose is that: a display device having a display area containing a pixel comprising: the pixel includes a first TFT having an oxide semiconductor, a gate insulating film is formed on the oxide semiconductor, a first gate electrode is formed on the gate insulating film, a first source/drain electrode formed by a metal or an alloy contacts a source or a drain of the semiconductor the first gate electrode and the first source/drain electrode are formed by the same material.
1. A display device having a display area containing a pixel comprising:
the pixel includes a first TFT having an oxide semiconductor,
a gate insulating film is formed on the oxide semiconductor, a first gate electrode is formed on the gate insulating film,
a first source/drain electrode formed by a metal or an alloy in contact with a source or a drain of the semiconductor,
a first insulating film is formed to cover the oxide semiconductor, the gate electrode, and the first source/drain electrode, and a first through hole is formed in the first insulating film, and on the first source/drain electrode,
a second source/drain electrode connects with the first source/drain electrode through the first through hole formed in the first insulating film, wherein
the first source/drain electrode exists at a bottom of the first through hole formed in the first insulating film.
2. The display device according to claim 1 ,
wherein the gate insulating film is formed in island shape to cover a channel of the first TFT, the gate insulating film does not exist between the first source/drain electrode and the oxide semiconductor.
3. The display device according to claim 1 ,
wherein a channel of the first TFT connects with the first source/drain electrode via an ion doped area of the oxide semiconductor.
4. The display device according to claim 1 ,
wherein a driving circuit is formed outside of the display area,
the driving circuit includes a second TFT having Poly-Si semiconductor.
5. The display device according to claim 4 ,
wherein the second TFT is covered by a second insulating film, the second insulating film is covered by the first insulating film,
a third source/drain electrode connects with the Poly-Si semiconductor through a third through hole formed in the first insulating film and the second insulating film,
the Poly-Si semiconductor exists at the bottom of the through hole in the second insulating film.
6. The display device according to claim 4 ,
wherein the first TFT and second TFT are top gate type TFTs.
7. The display device according to claim 1 ,
wherein the display device is a liquid crystal display device.
8. The display device according to claim 1 ,
wherein the display device is an organic EL display device.