Capacitor and organic light emitting display device

• US 8,367,448 B2
• Filed: 10/22/2010
• Issued: 02/05/2013
• Est. Priority Date: 03/12/2010
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Inventors: Choi, Chaun-Gi, Jeong, Jong-Han, Park, Chang-Mo
• Primary Examiner(s): Toledo, Fernando L
• Assistant Examiner(s): KUSUMAKAR, KAREN M
• Application Number:
  US12/926,049
• Publication Number:
  US 20110220888A1
• Time in Patent Office: 837 Days
• Field of Search: 438 22- 47, 438386-399, 257 79-103, 257531-535
• US Class Current: 438/43
• 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 28/60 Electrodes
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors

Abstract

A capacitor of an organic light emitting display device includes a first metal layer on a substrate, a first insulating layer on the first metal layer, an oxide semiconductor layer on the first insulating layer, the oxide semiconductor layer corresponding to the first metal layer, a second insulating layer on the first insulating layer, the second insulating layer including an opening exposing a portion of the oxide semiconductor layer, and a second metal layer on the second insulating layer and in the opening, the second metal layer being connected to the exposed portion of the oxide semiconductor layer.

Claims

1. A capacitor of an organic light emitting display device, the capacitor comprising:

a first metal layer on a substrate;

a first insulating layer on the first metal layer;

an oxide semiconductor layer on the first insulating layer, the oxide semiconductor layer corresponding to the first metal layer;

a second insulating layer on the first insulating layer, the second insulating layer including an opening exposing a portion of the oxide semiconductor layer; and

a second metal layer on the second insulating layer and in the opening, the second metal layer being connected to the exposed portion of the oxide semiconductor layer.

2. The capacitor as claimed in claim 1, wherein the second insulating layer covers edge portions of the oxide semiconductor layer and exposes a center portion of the oxide semiconductor layer through the opening.

3. The capacitor as claimed in claim 1, wherein the opening in the second insulating layer exposes a majority of an upper surface of the oxide semiconductor layer.

4. The capacitor as claimed in claim 3, wherein a contact surface between the second metal layer and the oxide semiconductor layer overlaps an entire bottom of the opening.

5. The capacitor as claimed in claim 1, wherein the first metal layer, the first insulating layer, the oxide semiconductor layer, and the second metal layer are sequentially stacked through the opening of the second insulating layer.

6. An organic light emitting display device, comprising:

an organic light emitting element;

a thin film transistor electrically connected to the organic light emitting element; and

a capacitor electrically connected to the organic light emitting element, the capacitor including;

a first metal layer on a substrate,

a first insulating layer on the first metal layer,

an oxide semiconductor layer on the first insulating layer, the oxide semiconductor layer corresponding to the first metal layer,

a second insulating layer on the first insulating layer, the second insulating layer including a first opening exposing a portion of the oxide semiconductor layer, and

a second metal layer on the second insulating layer and in the first opening, the second metal layer being connected to the exposed portion of the oxide semiconductor layer.

7. The organic light emitting display device as claimed in claim 6, wherein the second insulating layer covers edge portions of the oxide semiconductor layer and exposes a center portion of the oxide semiconductor layer through the first opening.

8. The organic light emitting display device as claimed in claim 6, wherein the first metal layer, the first insulating layer, the oxide semiconductor layer, and the second metal layer are sequentially stacked through the first opening of the second insulating layer.

9. The organic light emitting display device as claimed in claim 6, wherein the thin film transistor includes:

a gate electrode on the substrate, the gate electrode being on a same level as the first metal layer;

an active layer on a same level as the oxide semiconductor layer, the active layer and oxide semiconductor layer including a same material and being positioned on the first insulating layer; and

source-drain electrodes on a same level as the second metal layer, the source-drain electrodes being positioned on the second insulating layer and electrically connected to the active layer through a second opening in the second insulating layer.

10. The organic light emitting display device as claimed in claim 6, further comprising a passivation layer between the organic light emitting element and each of the thin film transistor and the capacitor, the organic light emitting element being electrically connected to the thin film transistor and the capacitor through the passivation layer.

11. A method of forming an organic light emitting display device, comprising:

forming an organic light emitting element on a substrate;

forming a thin film transistor electrically connected to the organic light emitting element; and

forming a capacitor electrically connected to the organic light emitting element, the capacitor including;

a first metal layer on the substrate,

a first insulating layer on the first metal layer,

an oxide semiconductor layer on the first insulating layer, the oxide semiconductor layer corresponding to the first metal layer,

a second insulating layer on the first insulating layer, the second insulating layer including an opening exposing a portion of the oxide semiconductor layer, and

a second metal layer on the second insulating layer and in the opening, the second metal layer being connected to the exposed portion of the oxide semiconductor layer.

12. The method as claimed in claim 11, wherein forming the thin film transistor includes forming a gate electrode and an active layer, the gate electrode being formed simultaneously and on a same level as the first metal layer, and the active layer being formed simultaneously and on a same level as the oxide semiconductor layer.

13. The method as claimed in claim 11, further comprising using plasma to process the exposed portion of the oxide semiconductor layer through the opening of the second insulating layer, such that resistance of the oxide semiconductor layer is reduced.