Organic thin-film transistor manufacturing method, organic thin-film transistor, and organic thin-film transistor sheet

1. An organic thin-film transistor manufacturing method comprising the steps of:

a) forming a gate electrode on a substrate;

b) forming a gate insulating layer on the substrate;

c) forming an organic semiconductor layer on the substrate;

d) forming an organic semiconductor layer protective layer on the organic semiconductor layer;

e) removing a part of the organic semiconductor layer protective layer; and

f) forming a source electrode and a drain electrode at portions where the organic semiconductor layer protective layer has been removed, so that the source electrode and drain electrode contacts the organic semiconductor layer.

2. The organic thin-film transistor manufacturing method of claim 1 , wherein the organic semiconductor layer protective layer is formed so as to contact the organic semiconductor layer.

3. The organic thin-film transistor manufacturing method of claim 1 , between the steps d) and e), further comprising the steps of g) forming a light sensitive resin layer contacting the organic semiconductor layer protective layer, h) exposing the light sensitive layer, and i) developing the exposed light sensitive layer with a developer.

4. The organic thin-film transistor manufacturing method of claim 3 , wherein the steps e) and i) are simultaneously carried out.

5. The organic thin-film transistor manufacturing method of claim 3 , wherein the developer is an aqueous alkali solution.

6. The organic thin-film transistor manufacturing method of claim 1 , wherein the layer formed on the organic semiconductor layer has a light transmittance of not more than 10%.

7. The organic thin-film transistor manufacturing method of claim 3 , wherein the light sensitive layer has a light transmittance of not more than 10%.

8. The organic thin-film transistor manufacturing method of claim 6 , wherein the organic semiconductor layer protective layer has a light transmittance of not more than 10%.

9. The organic thin-film transistor manufacturing method of claim 1 , wherein the organic semiconductor layer protective layer contains a hydrophilic polymer.

10. The organic thin-film transistor manufacturing method of claim 1 , wherein the organic semiconductor layer protective layer is formed by coating an aqueous hydrophilic polymer solution or an aqueous hydrophilic polymer dispersion.

11. The organic thin-film transistor manufacturing method of claim 1 , wherein the organic semiconductor layer protective layer contains inorganic oxides or inorganic nitrides.

12. The organic thin-film transistor manufacturing method of claim 1 , wherein the source electrode is formed from a conductive paste containing metal particles, a conductive ink or a metal film precursor.

13. The organic thin-film transistor manufacturing method of claim 1 , wherein the drain electrode is formed from a conductive paste containing metal particles, a conductive ink or a metal film precursor.

14. The organic thin-film transistor manufacturing method of claim 1 , wherein the source electrode contains a conductive polymer.

15. The organic thin-film transistor manufacturing method of claim 1 , wherein the drain electrode contains a conductive polymer.

16. The organic thin-film transistor manufacturing method of claim 1 , wherein the substrate is comprised of a resin.