Semiconductor device and display unit

1. A semiconductor device comprising:

a substrate;

a gate electrode provided on the substrate;

an oxide semiconductor film provided on the substrate with the gate electrode being interposed therebetween, the oxide semiconductor film including a channel region that faces the gate electrode and a low-resistance region adjacent to the channel region;

a first electrode that contains a constituent material same as a constituent material of the gate electrode, the first electrode having a same thickness as a thickness of the gate electrode;

a second electrode having at least a portion that faces the first electrode, the second electrode containing a constituent material same as a constituent material of the oxide semiconductor film; and

a third electrode having at least a portion that is provided at a position facing the first electrode with the second electrode being interposed therebetween, the third electrode being electrically coupled to the first electrode and to the low-resistance region.

2. The semiconductor device according to claim 1 , further comprising a channel protective film that covers the channel region of the oxide semiconductor film.

3. The semiconductor device according to claim 2 , wherein, in a plan view, the channel protective film is provided in inner side of the gate electrode, and is provided to have a width larger than a channel width of the oxide semiconductor film.

4. The semiconductor device according to claim 1 , further comprising a source-drain electrode electrically coupled to the low-resistance region of the oxide semiconductor film.

5. The semiconductor device according to claim 4 , further comprising:

a first insulating film provided between the oxide semiconductor film and the gate electrode; and

a second insulating film that contains metal, and is in contact with the low-resistance region of the oxide semiconductor film.

6. The semiconductor device according to claim 5 , further comprising a third insulating film that covers the second insulating film, wherein

the source-drain electrode is electrically coupled to the low-resistance region of the oxide semiconductor film through a contact hole provided on the third insulating film and the second insulating film.

7. The semiconductor device according to claim 6 , wherein the second insulating film and the third insulating film are provided between the second electrode and the third electrode.

8. The semiconductor device according to claim 5 , wherein the metal comprises aluminum.

9. The semiconductor device according to claim 4 , wherein the source/drain electrode is electrically coupled to the first electrode.

10. The semiconductor device according to claim 4 , wherein the source/drain electrode is integral with the first electrode and the third electrode.

11. The semiconductor device of claim 4 , wherein the source/drain electrode extends along a sidewall of the low-resistance region.

12. The semiconductor device according to claim 1 , wherein the second electrode has a same thickness as a thickness of the low-resistance region of the oxide semiconductor film.

13. The semiconductor device according to claim 1 , wherein the first electrode, the second electrode, and the third electrode are provided in this order from the substrate.

14. A display unit comprising:

a semiconductor device; and

a display element layer that is provided on the semiconductor device, and includes a plurality of pixels,

the semiconductor device including

a substrate,

a gate electrode provided on the substrate,

an oxide semiconductor film provided on the substrate with the gate electrode being interposed therebetween, the oxide semiconductor film including a channel region that faces the gate electrode and a low-resistance region adjacent to the channel region,

a first electrode that contains a constituent material same as a constituent material of the gate electrode, the first electrode having a same thickness as a thickness of the gate electrode,

a second electrode having at least a portion that faces the first electrode, the second electrode containing a constituent material same as a constituent material of the oxide semiconductor film,

a third electrode having at least a portion that is provided at a position facing the first electrode with the second electrode being interposed therebetween, the third electrode being electrically coupled to the first electrode; and

a source/drain electrode electrically coupled to the low-resistance region and to the first electrode.

15. The display unit according to claim 14 , wherein the semiconductor device includes a pixel circuit of each of the plurality of pixels, the pixel circuit including a driving transistor and a switching transistor, and the gate electrode and the oxide semiconductor film configure the driving transistor in the pixel circuit.

16. The display unit according to claim 15 , wherein the second electrode is provided integrally with the oxide semiconductor film.

17. The display unit according to claim 14 , wherein the semiconductor device includes a pixel circuit of each of the plurality of pixels, the pixel circuit including a driving transistor and a switching transistor, and the gate electrode and the oxide semiconductor film configure the switching transistor in the pixel circuit.

18. The display unit according to claim 17 , wherein the second electrode is provided integrally with the oxide semiconductor film.

19. The semiconductor device of claim 14 , wherein the source/drain electrode is integral with the first electrode and the third electrode.