THIN FILM TRANSISTOR AND ORGANIC LIGHT EMITTING DIODE DISPLAY

• US 20150001484A1
• Filed: 12/04/2013
• Published: 01/01/2015
• Est. Priority Date: 06/28/2013
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Yang, Hui-Won, CHOI, CHAUN-GI, Kim, Sun-Kwang, Park, Sang-Il
• Granted Patent: US 9,214,564 B2
• Time in Patent Office: Days
• US Class Current: 257/40
• CPC Class Codes: H01L 29/41733 for thin film transistors with insulated gate
• 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: H10K 59/12 Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1213 the pixel elements being TFTs

Abstract

A thin film transistor (TFT) includes a gate electrode disposed on a substrate. An oxide semiconductor layer is disposed on the gate electrode. An insulation layer is disposed on the oxide semiconductor layer. The insulation layer includes a first contact hole that exposes a first part of the oxide semiconductor layer corresponding to a first end of the gate electrode and a second contact hole that exposes a second part of the oxide semiconductor layer corresponding to an opposite end of the gate electrode. A source electrode is disposed on the insulation layer and contacts the first part of the oxide semiconductor layer through the first contact hole. A drain electrode is disposed on the insulation layer and contacts the second part of the oxide semiconductor layer through the second contact hole.

Claims

1. A thin film transistor (TFT), comprising:

a first gate electrode disposed on a substrate;

a first oxide semiconductor layer disposed on the first gate electrode;

an insulation layer disposed on the first oxide semiconductor layer, the insulation layer including a first contact hole that exposes a first part of the first oxide semiconductor layer corresponding to a first end of the first gate electrode and a second contact hole that exposes a second part of the first oxide semiconductor layer corresponding to a second end of the first gate electrode;

a first source electrode disposed on the insulation layer, the first source electrode contacting a part of the first part of the first oxide semiconductor layer through the first contact hole; and

a first drain electrode disposed on the insulation layer, and the first drain electrode contacting a part of the second part of the first oxide semiconductor layer through the second contact hole.

2. The thin film transistor (TFT) of claim 1, wherein a remaining part of the first part of the first oxide semiconductor layer is exposed by the first contact hole.

3. The thin film transistor (TFT) of claim 2, wherein a remaining part of the second part of the first oxide semiconductor layer is exposed by the second contact hole.

4. An organic light emitting diode (OLED) display, comprising the thin film transistor (TFT) of claim 1, wherein:

a driving thin film transistor (TFT) including a second gate electrode is connected to the first drain electrode of the thin film transistor (TFT); and

an organic light emitting diode (OLED) is connected to the driving thin film transistor (TFT).

5. The organic light emitting diode (OLED) display of claim 4, wherein the driving thin film transistor (TFT) further comprises the second gate electrode disposed on the substrate and a second oxide semiconductor layer disposed on the second gate electrode,

wherein the insulation layer further comprises a third contact hole that exposes a third part of the second oxide semiconductor layer corresponding to a first end of the second gate electrode and a fourth contact hole that exposes a fourth part of the second oxide semiconductor layer corresponding to a second end of the second gate electrode, and

wherein the driving thin film transistor (TFT) further comprises a second source electrode disposed on the insulation layer and contacting the third part of the second oxide semiconductor layer through the third contact hole and a second drain electrode disposed on the insulation layer and contacting the fourth part of the second oxide semiconductor layer through the fourth contact hole.

6. The organic light emitting diode (OLED) display of claim 5, wherein the second source electrode covers the third contact hole.

7. The organic light emitting diode (OLED) display of claim 6, wherein the second drain electrode covers the fourth contact hole.

8. The organic light emitting diode (OLED) display of claim 5, wherein a first length between the first contact hole and the second contact hole is smaller than a second length between the third contact hole and the fourth contact hole.

9. The organic light emitting diode (OLED) display of claim 5, wherein the second drain electrode is connected to the organic light emitting diode (OLED).

10. A thin film transistor (TFT), comprising:

a gate electrode disposed on a substrate;

an oxide semiconductor layer disposed on the gate electrode;

an insulation layer disposed on the oxide semiconductor layer, and the insulating layer including a contact hole that exposes a partial surface of the oxide semiconductor layer; and

a source electrode and a drain electrode, each disposed on the insulation layer and each contacting a part of the exposed partial surface of the oxide semiconductor layer through the contact hole.

11. The thin film transistor (TFT) of claim 10, wherein a remaining part of the partial surface of the oxide semiconductor layer is exposed by the contact hole.

12. An organic light emitting diode (OLED) including a thin film transistor (TFT), the TFT comprising:

a gate electrode disposed on a substrate;

an oxide semiconductor layer disposed on the gate electrode;

an insulation layer disposed on the oxide semiconductor layer, the insulation layer including a first contact hole that exposes a first part of the oxide semiconductor layer and a second contact hole that exposes a second part of the oxide semiconductor layer;

a source electrode disposed on the insulation layer, the source electrode contacting the first part of the first oxide semiconductor layer through the first contact hole; and

a drain electrode disposed on the insulation layer, the drain electrode contacting the second part of the oxide semiconductor layer through the second contact hole.

13. The OLED of claim 12, wherein the first part of the oxide semiconductor layer is exposed by the first contact hole.

14. The OLED of claim 12, wherein the second part of the oxide semiconductor layer is exposed by the second contact hole.

15. The OLED of claim 12, further including a driving TFT.

16. The OLED of claim 15, wherein the driving TFT includes a driving TFT gate electrode connected to the drain electrode of the TFT, the driving TFT gate electrode is disposed on the substrate, and a driving TFT oxide semiconductor layer is disposed on the driving TFT gate electrode.

17. The OLED of claim 16, wherein the insulation layer further includes a third contact hole that exposes the driving TFT oxide semiconductor layer and a fourth contact hole that exposes the driving TFT oxide semiconductor layer.

18. The OLED of claim 16, wherein the driving TFT further comprises a driving TFT source electrode disposed on the insulation layer and contacting the driving TFT oxide semiconductor layer through the third contact hole and a driving TFT drain electrode is disposed on the insulation layer and contacting the driving TFT oxide semiconductor layer thought the fourth contact hole.

19. The OLED of claim 18, wherein the driving TFT source electrode covers the third contact hole and the driving TFT drain electrode covers the fourth contact hole.

20. The OLED of claim 17, wherein a first length between the first contact hole and the second contact hole is smaller than a second length between the third contact hole and the fourth contact hole.