Display device

1. A display device comprising:

a first gate electrode;

a first gate insulating film over the first gate electrode;

an oxide semiconductor film over the first gate insulating film;

a source electrode and a drain electrode over the oxide semiconductor film, wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor film;

a second gate insulating film over the source electrode, the drain electrode and the oxide semiconductor film;

a second gate electrode over the second gate insulating film;

an organic resin film having flatness over the second gate insulating film;

a pixel electrode over the organic resin film having flatness, wherein the pixel electrode is electrically connected to either the source electrode or the drain electrode;

a first alignment film over and in contact with the second gate electrode and the pixel electrode;

a liquid crystal layer over the first alignment film;

a second alignment film over the liquid crystal layer;

a counter electrode over the second alignment film; and

a counter substrate over the counter electrode,

wherein a concentration of hydrogen atoms contained in the oxide semiconductor film and measured by secondary ion mass spectrometry is less than 1×10 16 cm −3 .

2. A display device comprising:

a first gate electrode;

a first gate insulating film over the first gate electrode;

an oxide semiconductor film over the first gate insulating film;

a source electrode and a drain electrode over the oxide semiconductor film, wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor film;

a second gate insulating film over the source electrode, the drain electrode and the oxide semiconductor film;

a second gate electrode over the second gate insulating film;

an organic resin film having flatness over the second gate insulating film;

a pixel electrode over the organic resin film having flatness, wherein the pixel electrode is electrically connected to either the source electrode or the drain electrode;

an EL layer over the pixel electrode;

a counter electrode over the EL layer;

a sealing material over and in contact with the second gate electrode and the counter electrode; and

a counter substrate over the sealing material,

wherein a concentration of hydrogen atoms contained in the oxide semiconductor film and measured by secondary ion mass spectrometry is less than 1×10 16 cm −3 .

3. A display device comprising:

a first gate electrode;

a first gate insulating film over the first gate electrode;

an oxide semiconductor film over the first gate insulating film;

a source electrode and a drain electrode over the oxide semiconductor film, wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor film;

a second gate insulating film over the source electrode, the drain electrode and the oxide semiconductor film;

a second gate electrode over the second gate insulating film;

an organic resin film having flatness over the second gate insulating film;

a pixel electrode over the organic resin film having flatness, wherein the pixel electrode is electrically connected to either the source electrode or the drain electrode; and

a filler over and in contact with the second gate electrode and the pixel electrode, wherein a spherical particle including a cavity is provided in the filler, the cavity contains a black region and a white region, and a space around the cavity is filled with a liquid,

wherein a concentration of hydrogen atoms contained in the oxide semiconductor film and measured by secondary ion mass spectrometry is less than 1×10 16 cm −3 .

4. A display device comprising:

a first gate electrode;

a first gate insulating film over the first gate electrode;

an oxide semiconductor film over the first gate insulating film;

a source electrode and a drain electrode over the oxide semiconductor film, wherein the source electrode and the drain electrode are electrically connected to the oxide semiconductor film;

a second gate insulating film over the source electrode, the drain electrode and the oxide semiconductor film;

a second gate electrode over the second gate insulating film;

an organic resin film having flatness over the second gate insulating film;

a pixel electrode over the organic resin film having flatness, wherein the pixel electrode is electrically connected to either the source electrode or the drain electrode; and

an electronic ink layer over and in contact with the second gate electrode and the pixel electrode, wherein the electronic ink layer comprises a microcapsule in which positively charged white microparticles and negatively charged black microparticles are encapsulated,

wherein a concentration of hydrogen atoms contained in the oxide semiconductor film and measured by secondary ion mass spectrometry is less than 1×10 16 cm −3 .

5. A display device according to claim 1 , wherein the organic resin film does not overlap the second gate electrode.

6. A display device according to claim 2 , wherein the organic resin film does not overlap the second gate electrode.

7. A display device according to claim 3 , wherein the organic resin film does not overlap the second gate electrode.

8. A display device according to claim 4 , wherein the organic resin film does not overlap the second gate electrode.

9. A display device according to claim 1 , further comprising a passivation film over the second gate electrode and the second gate insulating film.

10. A display device according to claim 2 , further comprising a passivation film over the second gate electrode and the second gate insulating film.

11. A display device according to claim 3 , further comprising a passivation film over the second gate electrode and the second gate insulating film.

12. A display device according to claim 4 , further comprising a passivation film over the second gate electrode and the second gate insulating film.

13. A display device according to claim 1 , wherein a carrier density of the oxide semiconductor film is less than 1×10 12 cm −3 at 300 K.

14. A display device according to claim 2 , wherein a carrier density of the oxide semiconductor film is less than 1×10 12 cm −3 at 300 K.

15. A display device according to claim 3 , wherein a carrier density of the oxide semiconductor film is less than 1×10 12 cm −3 at 300 K.

16. A display device according to claim 4 , wherein a carrier density of the oxide semiconductor film is less than 1×10 12 cm −3 at 300 K.

17. A display device according to claim 1 , wherein the oxide semiconductor film comprises a material selected from the group consisting of In—Sn—Ga—Zn—O, In—Ga—Zn—O, In—Sn—Zn—O, In—Al—Zn—O, Sn—Ga—Zn—O, Al—Ga—Zn—O, Sn—Al—Zn—O, In—Zn—O, Sn—Zn—O, Al—Zn—O, Zn—Mg—O, Sn—Mg—O, In—Mg—O; In—O, Sn—O, and Zn—O.

18. A display device according to claim 2 , wherein the oxide semiconductor film comprises a material selected from the group consisting of In—Sn—Ga—Zn—O, In—Ga—Zn—O, In—Sn—Zn—O, In—Al—Zn—O, Sn—Ga—Zn—O, Al—Ga—Zn—O, Sn—Al—Zn—O, In—Zn—O, Sn—Zn—O, Al—Zn—O, Zn—Mg—O, Sn—Mg—O, In—Mg—O; In—O, Sn—O, and Zn—O.

19. A display device according to claim 3 , wherein the oxide semiconductor film comprises a material selected from the group consisting of In—Sn—Ga—Zn—O, In—Ga—Zn—O, In—Sn—Zn—O, In—Al—Zn—O, Sn—Ga—Zn—O, Al—Ga—Zn—O, Sn—Al—Zn—O, In—Zn—O, Sn—Zn—O, Al—Zn—O, Zn—Mg—O, Sn—Mg—O, In—Mg—O; In—O, Sn—O, and Zn—O.

20. A display device according to claim 4 , wherein the oxide semiconductor film comprises a material selected from the group consisting of In—Sn—Ga—Zn—O, In—Ga—Zn—O, In—Sn—Zn—O, In—Al—Zn—O, Sn—Ga—Zn—O, Al—Ga—Zn—O, Sn—Al—Zn—O, In—Zn—O, Sn—Zn—O, Al—Zn—O, Zn—Mg—O, Sn—Mg—O, In—Mg—O; In—O, Sn—O, and Zn—O.