THIN FILM TRANSISTOR AND DISPLAY SUBSTRATE HAVING THE SAME

• US 20160172506A1
• Filed: 02/24/2016
• Published: 06/16/2016
• Est. Priority Date: 01/15/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Kim, Jong Yun, AHN, Taekyung, Kim, Youngdae
• Granted Patent: US 9,859,435 B2
• Time in Patent Office: Days
• CPC Class Codes: C22C 27/04 Alloys based on tungsten or molybdenum
• CPC Class Codes: H01L 27/1225 with semiconductor materials not belonging to the group IV of the periodic table, e.g. InGaZnO
• CPC Class Codes: H01L 27/1251 comprising TFTs having a different architecture, e.g. top- and bottom gate TFTs
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• CPC Class Codes: H01L 29/454 on thin film AIII-BV compounds
• CPC Class Codes: H01L 29/458 for thin film silicon, e.g. source or drain electrode
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 2924/1205 Capacitor
• CPC Class Codes: H01L 2924/13069 Thin film transistor [TFT]
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors

Abstract

A display substrate includes a base substrate, a semiconductor active layer disposed on the base substrate, a gate insulating layer disposed on the semiconductor active layer, a first conductive pattern group disposed on the gate insulating layer and including at least a gate electrode, a second conductive pattern group insulated from the first conductive pattern group and including at least a source electrode, a drain electrode, and a data pad. The second conductive pattern group includes a first conductive layer and a second conductive layer disposed on the first conductive layer to prevent the first conductive layer from being corroded and oxidized.

Claims

1-5. -5. (canceled)

6. A display substrate, comprising:

a base substrate;

a first thin film transistor disposed on the base substrate and comprising a first gate electrode and a first semiconductor active layer;

a second thin film transistor electrically connected to the first thin film transistor, the second thin film transistor comprising a second gate electrode and a second semiconductor active layer; and

an organic light emitting device electrically connected to the second thin film transistor,

wherein the first semiconductor active layer comprising a first material and the second semiconductor active layer comprising a second material different from the first material.

7. The display substrate of claim 6, wherein the first material comprises a poly-silicon, and the second material comprises an oxide semiconductor.

8. The display substrate of claim 7, wherein the oxide semiconductor comprises at least one of Zn, In, Ga, Sn, and a mixture thereof.

9. The display substrate of claim 7, wherein the first semiconductor active layer is disposed between the base substrate and the first gate electrode, and the second semiconductor active layer is disposed between the base substrate and the second gate electrode.

10. The display substrate of claim 7, wherein the first semiconductor active layer is disposed between the base substrate and the first gate electrode, and the second gate electrode is disposed between the base substrate and the second semiconductor active layer.

11. The display substrate of claim 7, further comprising an inter-insulating layer disposed on the first gate electrode and the second gate electrode to insulate the first gate electrode and the second gate electrode from the first semiconductor active layer and the second semiconductor active layer, the inter-insulating layer comprising at least one of silicon oxide or silicon nitride.

12. The display substrate of claim 7, further comprising a buffer layer disposed on the base substrate to make contact with the base substrate, the buffer layer comprising at least one of silicon oxide or silicon nitride.

13. The display substrate of claim 7, further comprising a protective layer disposed between the first thin film transistor and the organic light emitting device, the protective layer being disposed between the second thin film transistor and the organic light emitting device, and the protective layer comprising at least one of silicon oxide or silicon nitride.

14. The display substrate of claim 6, further comprising a light blocking layer overlapped with at least one of the first semiconductor active layer or the second semiconductor active layer.

15. The display substrate of claim 6, wherein the first material comprises an oxide semiconductor.

16. The display substrate of claim 15, wherein the first semiconductor active layer is disposed between the base substrate and the first gate electrode.

17. The display substrate of claim 16, wherein the second semiconductor active layer is disposed between the base substrate and the second gate electrode.

18. The display substrate of claim 16, wherein the second gate electrode is disposed between the base substrate and the second semiconductor active layer.

19. The display substrate of claim 16, further comprising an inter-insulating layer disposed on the first gate electrode and the second gate electrode to insulate the first gate electrode and the second gate electrode from the first semiconductor active layer and the second semiconductor active layer, the inter-insulating layer comprising at least one of silicon oxide or silicon nitride.

20. The display substrate of claim 16, further comprising a buffer layer disposed on the base substrate to make contact with the base substrate, the buffer layer comprising at least one of silicon oxide or silicon nitride.

21. The display substrate of claim 16, further comprising a protective layer disposed between the first thin film transistor and the organic light emitting device, the protective layer being disposed between the second thin film transistor and the organic light emitting device, and the protective layer comprising at least one of silicon oxide or silicon nitride.

22. The display substrate of claim 15, wherein the oxide semiconductor comprises at least one of Zn, In, Ga, Sn, and a mixture thereof.

23. The display substrate of claim 15, further comprising a light blocking layer overlapped with the first semiconductor active layer.

24. A display substrate, comprising:

a base substrate on which a plurality of pixel areas are defined;

a first thin film transistor comprising a first gate electrode and a first semiconductor active layer;

a second thin film transistor electrically connected to the first thin film transistor, the second thin film transistor comprising a second gate electrode and a second semiconductor active layer; and

an organic light emitting device electrically connected to the second thin film transistor,

wherein the first thin film transistor, the second thin film transistor and the organic light emitting device are disposed in each of the plurality of pixel areas, the first semiconductor active layer comprises a poly-silicon, and the second semiconductor active layer comprises an oxide semiconductor.

25. The display substrate of claim 24, wherein the first thin film transistor comprises a first source electrode connected to one side of the first semiconductor active layer and a first drain electrode connected to the other side of the first semiconductor active layer, and the second film transistor comprises a second source electrode connected to one side of the second semiconductor active layer and a second drain electrode connected to the other side of the second semiconductor active layer.

26. The display substrate of claim 25, further comprising:

a first inter-insulating layer disposed between the first gate electrode and the first source electrode, the first inter-insulating layer being disposed between the first gate electrode and the first drain electrode, and the first inter-insulating layer comprising silicon nitride; and

a second inter-insulating layer disposed between the first inter-insulating layer and the first source electrode, the second inter-insulating layer being disposed between the first inter-insulating layer and the first drain electrode, and the second inter-insulating layer comprising silicon oxide.

27. The display substrate of claim 25, further comprising:

a first capacitor electrode disposed on a same layer of the first gate electrode and the second gate electrode; and

a second capacitor electrode disposed on a same layer of the first source electrode, the second source electrode, the first drain electrode and the second drain electrode.

28. The display substrate of claim 25, wherein each of the first source electrode, the second source electrode, the first drain electrode and the second drain electrode comprise:

a first conductive layer comprising one of copper, a copper alloy, aluminum, and an aluminum alloy; and

a second conductive layer disposed on the first conductive layer and comprising a molybdenum-nickel alloy.

29. The display substrate of claim 25, wherein each of the first source electrode, the second source electrode, the first drain electrode and the second drain electrode comprise:

a first conductive layer comprising one of copper, a copper alloy, aluminum, and an aluminum alloy;

a second conductive layer disposed on the first conductive layer; and

a third conductive layer disposed under the first conductive layer,

wherein the second conductive layer and the third conductive layer comprising a molybdenum-nickel-titanium alloy.

30. The display substrate of claim 29, wherein the molybdenum-nickel-titanium alloy contains nickel of about 15 at % to about 30 at % with respect to an aggregate of the molybdenum-nickel-titanium alloy, and titanium of about 10 at % to about 20 at % with respect to the aggregate of the molybdenum-nickel-titanium alloy.

31. The display substrate of claim 24, further comprising a light blocking layer overlapped with the second semiconductor active layer.

32. The display substrate of claim 24, wherein the oxide semiconductor comprises at least one of Zn, In, Ga, Sn, and a mixture thereof.

33. The display substrate of claim 24, wherein the first semiconductor active layer is disposed between the base substrate and the first gate electrode, and the second gate electrode is disposed between the base substrate and the second semiconductor active layer.

34. A display substrate, comprising:

a base substrate on which a plurality of pixel areas are defined;

a first thin film transistor comprising a first gate electrode and a first semiconductor active layer;

a second thin film transistor electrically connected to the first thin film transistor and comprising a second gate electrode and a second semiconductor active layer; and

an organic light emitting device electrically connected to the second thin film transistor, wherein the first thin film transistor, the second thin film transistor and the organic light emitting device are disposed in each of the plurality of pixel areas, the first semiconductor active layer comprises an oxide semiconductor, and the second semiconductor active layer comprises a material different from the oxide semiconductor.

35. The display substrate of claim 34, wherein the first semiconductor active layer is disposed between the base substrate and the first gate electrode, and the second gate electrode is disposed between the base substrate and the second gate electrode.

36. The display substrate of claim 34, further comprising a light blocking layer overlapped with the first semiconductor active layer.

37. The display substrate of claim 34, wherein the oxide semiconductor comprises at least one of Zn, In, Ga, Sn, and a mixture thereof.