Organic field effect transistor and method of manufacturing the same

• US 20050263756A1
• Filed: 05/12/2005
• Published: 12/01/2005
• Est. Priority Date: 05/12/2004
• Status: Active Grant

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Yatsunami, Ryuichi, Sakanoue, Kei
• Granted Patent: US 7,372,070 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H10K 10/464 Lateral top-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/466 Lateral bottom-gate IGFETs comprising only a single gate
• CPC Class Codes: H10K 10/84 Ohmic electrodes, e.g. source or drain electrodes
• CPC Class Codes: H10K 71/60 Forming conductive regions or layers, e.g. electrodes

Abstract

To provide an organic field effect transistor with stable characteristics and a long life span, an organic field effect transistor includes a gate electrode 8 formed on an organic semiconductor film 2 made of an organic semiconductor material with a gate insulating film 3 interposed therebetween; and a source electrode 6 and a drain electrode 7 provided so as to come in contacts with the organic semiconductor film with the gate electrode 8 interposed therebetween. At least one of the source electrode 6 and the drain electrode 7 is formed in contact with the organic semiconductor film 2 with charge injection layers 4 and 5 made of an inorganic material interposed therebetween.

Claims

1. An organic field effect transistor comprising:

a gate electrode, formed on an organic semiconductor film made of an organic semiconductor material with a gate insulating film interposed therebetween; and

a source electrode and a drain electrode, which are provided so as to come into contacts with the organic semiconductor film;

wherein at least one of the source electrode and the drain electrode is formed so as to come into contact with the organic semiconductor film with charge injection layer made of an inorganic material interposed therebetween, the organic semiconductor film using a hole as a carrier.

2. The organic field effect transistor according to claim 1, wherein the charge injection layer contains an oxide.

3. The organic field effect transistor according to claim 1, wherein the charge injection layer contains an oxide of a transitional metal.

4. The organic field effect transistor according to claim 1, wherein the charge injection layer is made of a molybdenum oxide or a vanadium oxide.

5. The organic field effect transistor according to claim 1, wherein the charge injection layer contains a nitride.

6. The organic field effect transistor according to claim 1, wherein the charge injection layer contains a nitride of a transitional metal.

7. The organic field effect transistor according to claim, 1 wherein the charge injection layer contains an oxy-nitride.

8. The organic field effect transistor according to claim, 1 wherein the charge injection layer contains an oxy-nitride of a transitional metal.

9. The organic field effect transistor according to claim, 1 wherein the charge injection layer contains a complex oxide containing a transitional metal.

10. The organic field effect transistor according to claim 1, wherein the organic semiconductor layer is formed of a high molecular layer.

11. The organic field effect transistor according to claim 1, further comprising:

a substrate having the gate electrode formed thereon,

wherein the organic semiconductor layer is formed on the gate electrode with the gate insulating film interposed therebetween, and

the source electrode and the drain electrode are formed on the organic semiconductor layer with the charge injection layer interposed therebetween, respectively.

12. The organic field effect transistor according to claim 11, wherein the charge injection layer is formed to cover the entire surface of the organic semiconductor layer.

13. The organic field effect transistor according to claim 1, further comprising:

a substrate having the source electrode and the drain electrode formed thereon,

wherein the organic semiconductor layer is formed to cover the source electrode and the drain electrode, and

the gate electrode is formed on the organic semiconductor layer with the gate insulating film interposed therebetween.

14. The organic field effect transistor according to claim 13,

wherein the gate insulating field is formed to cover the entire surface of the organic semiconductor layer and is formed thinner than the other regions under a region where the source electrode and the drain electrode are formed.

15. The organic field effect transistor according to claim 14,

wherein the gate insulating field is formed of two-layered films, except for being formed of a single film under the gate electrode.

16. A method of manufacturing an organic field effect transistor comprising the steps of:

forming a gate insulating film;

forming a gate electrode;

forming an organic semiconductor layer using a hole as a carrier;

forming a source electrode and a drain electrode, and

forming a charge injection layer on the interface between the source/drain electrode and the organic semiconductor layer.

17. The method of manufacturing an organic field effect transistor according to claim 16,

wherein the step of forming a charge injection layer includes a step of forming the charge injection layer on the organic semiconductor layer so as to cover the entire surface of the organic semiconductor layer.

18. An organic field effect transistor comprising:

a gate electrode formed on an organic semiconductor film made of an organic semiconductor material with a gate insulating film interposed therebetween; and

a source electrode and a drain electrode which are provide so as to come in contacts with the organic semiconductor film,

wherein at least one of the source electrode and the drain electrode is formed so as to come in contact with the organic semiconductor film with a buffer layer made of an inorganic material interposed therebetween.

19. The organic field effect transistor according to claim 18,

wherein the buffer layer contains an oxide.

20. The organic field effect transistor according to claim 18,

wherein the buffer layer contains an oxide of a transitional metal.

21. The organic field effect transistor according to claim 18,

wherein the buffer layer is made of a molybdenum oxide or vanadium oxide.

22. The organic field effect transistor according to claim 18,

wherein the buffer layer contains a nitride.

23. The organic field effect transistor according to claim 18,

wherein the buffer layer contains a nitride of a transitional metal.

24. The organic field effect transistor according to claim 18,

wherein the buffer layer contains an oxy-nitride.

25. The organic field effect transistor according to claim 18,

wherein the buffer layer contains an oxy-nitride of a transitional metal.

26. The organic field effect transistor according to claim 18,

wherein the buffer layer contains a complex oxide containing a transitional metal.

27. The organic field effect transistor according to claim 18,

wherein the organic semiconductor layer is formed of a high molecular layer.

28. The organic field effect transistor according to claim 18, further comprising:

a substrate having the gate electrode formed thereon,

wherein the organic semiconductor layer is formed on the gate electrode with the gate insulating film interposed therebetween,

and the source electrode and the drain electrode are formed on the organic semiconductor layer with the buffer layer interposed therebetween, respectively.

29. The organic field effect transistor according to claim 28,

wherein the buffer layer is formed to cover the entire surface of the organic semiconductor layer.

30. The organic field effect transistor according to claim 18, further comprising:

a substrate having the source electrode and the drain electrode formed thereon,

wherein the organic semiconductor layer is formed to cover the source electrode and the drain electrode, and

the gate electrode is formed on the organic semiconductor layer with the gate insulating film interposed there between.

31. The organic field effect transistor according to claim 30,

wherein the gate insulating film is formed to cover the entire surface of the organic semiconductor layer and is formed thinner than the other regions under a region where the source electrode and the drain electrode are formed.

32. The organic field effect transistor according to claim 31,

wherein the gate insulating film is formed of two-layered films, except for being formed of a single film under the gate electrode.

33. A method of manufacturing an organic field effect transistor comprising the steps of:

forming a gate insulating film;

forming a gate electrode;

forming an organic semiconductor layer;

forming a source electrode and a drain electrode, and

forming a buffer layer on the interface between the source/drain electrode and the organic semiconductor layer.

34. The method of manufacturing an organic field effect transistor according to claim 33,

wherein the step of forming a buffer layer includes a step of forming the buffer layer on the organic semiconductor layer so as cover the entire surface of the organic semiconductor layer.