Substrate for Display Device and Display Device Including the Same

• US 20180182832A1
• Filed: 12/06/2017
• Published: 06/28/2018
• Est. Priority Date: 12/28/2016
• Status: Active Grant

• Current Assignee: LG Display Co., Ltd.
• Original Assignee: LG Display Co., Ltd.
• Inventors: Lee, Jong-Won, Kim, Jeong-Oh, Bang, Jung-Ho
• Granted Patent: US 10,431,599 B2
• Time in Patent Office: Days
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active layer
• 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 27/1248 with a particular composition or shape of the interlayer dielectric specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H10K 50/81 Anodes
• CPC Class Codes: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/80517 Multilayers, e.g. transparent multilayers

Abstract

A substrate for a display device and a display device including the same are disclosed. The substrate includes a first thin-film transistor including an oxide semiconductor layer, a second thin-film transistor spaced apart from the first thin-film transistor and including a polycrystalline semiconductor layer, and a storage capacitor including at least two storage electrodes. One of the at least two storage electrodes is located in the same layer and is formed of the same material as a gate electrode of the second thin-film transistor that is disposed under the polycrystalline semiconductor layer, and another one of the at least two storage electrodes is located above the polycrystalline semiconductor layer with at least one insulation film interposed therebetween. Accordingly, lower power consumption and a larger area of the substrate are realized.

Claims

1. A display device, comprising:

a substrate;

a pixel on the substrate, the pixel including;

a first thin film transistor (TFT) on the substrate, the first TFT including;

a first gate electrode on the substrate,

at least a first part of a gate insulating film on the first gate electrode,

a first active layer formed of polycrystalline silicon on the first part of the gate insulating film, wherein a bottom surface of the first active layer faces the first gate electrode, and

a first source electrode and a first drain electrode contacting a top surface of the first active layer;

a second TFT on the substrate, the second TFT including a second active layer formed of oxide semiconductor; and

a light-emitting device electrically connected to the first TFT.

2. The display device of claim 1, further comprising a first interlayer insulation film on the first active layer contacting the first active layer, and wherein the second active layer is disposed on the first interlayer insulation film.

3. The display device of claim 2, wherein the first interlayer insulation film is formed of silicon nitride (SiNx).

4. The display device of claim 2, wherein the second TFT further includes:

a second gate electrode disposed on the first interlayer insulation film, and

at least a first part of a second interlayer insulation film between the second gate electrode and the second active layer.

5. The display device of claim 4, wherein the second interlayer insulation film is formed with a first opening, and wherein the first source electrode or the first drain electrode of the first TFT is disposed on a side surface of the first opening.

6. The display device of claim 4, wherein the second interlayer insulation film is on the first source electrode and the first drain electrode of the first TFT.

7. The light-emitting display device of claim 4, wherein the second TFT further includes at least a first part of a third interlayer insulation film between the second gate electrode and the second active layer, wherein the second interlayer insulation film contacts the second active layer and is formed of silicon oxide (SiOx), and wherein the third interlayer insulation film contacts the second gate electrode and is formed of silicon nitride (SiNx).

8. The display device of claim 1, wherein the second TFT further includes:

a second gate electrode disposed below the second active layer, wherein a bottom surface of the second active layer faces the second gate electrode, and

a second source electrode and a second drain electrode contacting a top surface of the second active layer.

9. The display device of claim 1, wherein the second TFT further includes:

a second gate electrode on the second active layer, wherein a bottom surface of the second gate electrode faces the second active layer, and

a second source electrode and a second drain electrode contacting a top surface of the second active layer.

10. The display device of claim 9, further comprising a light-shielding layer on the substrate overlapping with the second active layer, wherein the light-shielding layer is in a same layer as the first gate electrode of the first TFT.

11. The display device of claim 1, further comprising a storage electrode on the substrate, the storage electrode including a lower storage electrode and an upper storage electrode disposed on the lower storage electrode.

12. The display device of claim 11, further comprising a first interlayer insulation film on the first active layer contacting the first active layer, wherein the storage capacitor further includes at least a first part of the first interlayer insulation film and at least a second part of the gate insulating film disposed between the lower storage electrode and the upper storage electrode.

13. The display device of claim 11, wherein the lower storage electrode is in a same layer as the first gate electrode of the first TFT.

14. The display device of claim 11, wherein the second TFT further includes a second gate electrode, and wherein the upper storage electrode is in a same layer as the second gate electrode.

15. The display device of claim 1, further comprising a gate line on the substrate in a same layer as the first gate electrode, wherein the gate line overlaps with the first active layer.

16. The display device of claim 1, further comprising a gate-driving unit that drives a plurality of gate lines on the substrate, and wherein the gate-driving unit includes a third TFT including a third active layer formed of polycrystalline silicon.

17. The display device of claim 1, further comprising a data-driving unit and a multiplexer that drives a plurality of data lines on the substrate, and wherein the multiplexer includes a third TFT including a third active layer formed of polycrystalline silicon.

18. The display device of claim 1, wherein the light-emitting device is electrically connected to the first TFT, and wherein the first TFT is a driving TFT that drives the light-emitting device.

19. The display device of claim 1, wherein the second TFT is a switching TFT of the pixel, and the second TFT further includes a second drain electrode electrically connected to the first gate electrode, and a second source electrode connected to a data line on the substrate.

20. The display device of claim 1, wherein the second TFT is a sensing TFT of the pixel, and the second TFT further includes a second drain electrode electrically connected to the light-emitting device, and a second source electrode connected to a reference line on the substrate.

21. The display device of claim 1, wherein the light-emitting device comprises an anode electrode, a light-emitting stack, and a cathode electrode, wherein the anode electrode overlaps with the first TFT and the second TFT.

22. The display device of claim 1, wherein the light-emitting device comprises an anode electrode, a light-emitting stack, and a cathode electrode, wherein the display device further comprises a connection electrode electrically connected to the first drain electrode of the first TFT and the anode electrode.

23. The display device of claim 1, wherein the light-emitting device comprises an anode electrode, a light-emitting stack, and a cathode electrode, and wherein the anode electrode includes a transparent conductive film and an opaque conductive film.

24. The display device of claim 1, wherein the light-emitting device comprises an anode electrode, a light-emitting stack, and a cathode electrode, wherein the display device further comprises a bank layer on at least a part of the anode electrode, and wherein the bank layer includes a light-shielding material selected from at least one among a color pigment, and organic black and carbon materials.