DISPLAY DEVICE AND THE MANUFACTURING METHOD OF THE SAME

• US 20150263048A1
• Filed: 03/16/2015
• Published: 09/17/2015
• Est. Priority Date: 03/17/2014
• Status: Active Grant

• Current Assignee: Bendix Commercial Vehicle Systems LLC (Estate of Heinz Hermann Thiele), Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: UEMURA, Norihiro, Suzumura, Isao, Yamaguchi, Yohei, Miyake, Hidekazu
• Granted Patent: US 9,530,896 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G02F 1/133302 Rigid substrates, e.g. inorganic substrates
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• 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 27/124 with a particular composition, shape or layout of the wiring layers specially adapted to the circuit arrangement, e.g. scanning lines in LCD pixel circuits wiring structures per se H01L23/52
• 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 59/126 Shielding, e.g. light-blocking means over the TFTs
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals

Abstract

Provided are a reliable high performance thin film transistor and a reliable high performance display device. The display device has: a gate electrode which is formed on a substrate; a gate insulating film which is formed to cover the substrate and the gate electrode; an oxide semiconductor layer which is formed on the gate electrode through the gate insulating film; a channel protective layer which is in contact with the oxide semiconductor layer and formed on the oxide semiconductor layer; and source/drain electrodes which are electrically connected to the oxide semiconductor layer and formed to cover the oxide semiconductor layer. A metal oxide layer is formed on an upper part of the channel protective layer. The source/drain electrodes are formed to be divided apart on the channel protective layer and the metal oxide layer.

Claims

1. A display device comprising:

a gate electrode which is formed on a substrate;

a gate insulating film which is formed to cover the substrate and the gate electrode;

an oxide semiconductor layer which is formed on the gate electrode through the gate insulating film;

a channel protective layer which is in contact with the oxide semiconductor layer and formed on the oxide semiconductor layer; and

source/drain electrodes which are electrically connected to the oxide semiconductor layer and formed to cover the oxide semiconductor layer, and

wherein a metal oxide layer is formed on an upper part of the channel protective layer, and the source/drain electrodes are formed to be divided apart on the channel protective layer and the metal oxide layer.

3. The display device according to claim 1, wherein the gate electrode is formed of any of or an alloy in combination with titanium, molybdenum, aluminum, chromium, copper, tungsten, zirconium, tantalum, silver, and manganese.

5. The display device according to claim 1, wherein the metal oxide layer is formed of any oxide of or alloy oxide in combination with titanium, molybdenum, aluminum, chromium, copper, tungsten, zirconium, tantalum, silver, and manganese.

7. The display device according to claim 1, wherein the oxide semiconductor layer includes any of In—

Ga—

Zn—

O, In—

Al—

Zn—

O, In—

Sn—

Zn—

O, In—

Zn—

O, In—

Sn—

O, Zn—

O, and Sn—

O, as a main component.

9. The display device according to claim 1, wherein the metal oxide layer has a thickness between 50 nm and 200 nm.

11. The display device according to claim 1, wherein the substrate is a glass substrate, and a silicon nitride film is formed between the substrate and the gate electrode in a manner that the substrate and the gate electrode are not in direct contact with each other.

13. The display device according to claim 1, wherein the metal oxide layer is a light shielding layer for shielding entrance of external light to the oxide semiconductor layer.

15. The display device according to claim 1, wherein the display device is a liquid crystal display device in an FFS (Fringe Field Switching) mode for driving liquid crystal molecules using a fringe electric field.

17. The display device according to claim 1, wherein the display device is an organic EL display device in which organic light-emitting diodes are used as light emitting devices.

2. A display device comprising:

a gate electrode which is formed on a substrate;

a gate insulating film which is formed to cover the substrate and the gate electrode;

an oxide semiconductor layer which is formed on the gate electrode through the gate insulating film;

an etching stopper layer which is formed with a silicon oxide film formed to cover the oxide semiconductor layer; and

source/drain electrodes which are electrically connected to the oxide semiconductor layer through a plurality of contacts formed in the etching stopper layer, and are formed to cover the oxide semiconductor layer, and

wherein the source/drain electrodes are formed to be divided apart on the etching stopper layer, and a metal oxide layer is formed on an upper part of the etching stopper layer in a divided region.

4. The display device according to claim 2, wherein the gate electrode is formed of any of or an alloy in combination with titanium, molybdenum, aluminum, chromium, copper, tungsten, zirconium, tantalum, silver, and manganese.

6. The display device according to claim 2, wherein the metal oxide layer is formed of any oxide of or alloy oxide in combination with titanium, molybdenum, aluminum, chromium, copper, tungsten, zirconium, tantalum, silver, and manganese.

8. The display device according to claim 2, wherein the oxide semiconductor layer includes any of In—

Ga—

Zn—

O, In—

Al—

Zn—

O, In—

Sn—

Zn—

O, In—

Zn—

O, In—

Sn—

O, Zn—

O, and Sn—

O, as a main component.

10. The display device according to claim 2, wherein the metal oxide layer has a thickness between 50 nm and 200 nm.

12. The display device according to claim 2, wherein the substrate is a glass substrate, and a silicon nitride film is formed between the substrate and the gate electrode in a manner that the substrate and the gate electrode are not in direct contact with each other.

14. The display device according to claim 2, wherein the metal oxide layer is a light shielding layer for shielding entrance of external light to the oxide semiconductor layer.

16. The display device according to claim 2, wherein the display device is a liquid crystal display device in an FFS (Fringe Field Switching) mode for driving liquid crystal molecules using a fringe electric field.

18. The display device according to claim 2, wherein the display device is an organic EL display device in which organic light-emitting diodes are used as light emitting devices.

19. A method of manufacturing a display device, comprising:

(a) a step of forming a first metal film on a substrate to form a gate electrode by patterning the film;

(b) a step of forming a gate insulating film on the substrate and the gate electrode to cover the substrate and the gate electrode;

(c) a step of forming a semiconductor oxide film on the gate insulating film to form an oxide semiconductor layer by patterning the film;

(d) a step of forming a silicon oxide film on the gate insulating film and the oxide semiconductor layer to forma channel protective layer on the oxide semiconductor layer by patterning the film;

(e) a step of forming a second metal film, a third metal film, and a fourth metal film in order of lower layer, as source/drain electrodes, to cover the gate insulating film, the oxide semiconductor layer, and the channel protective layer, and removing the third metal film and the fourth metal film on the channel protective layer by patterning the films to expose the second metal film, and

(f) a step of performing an oxidation process on a surface of the substrate to form a metal oxide layer in a region where the second metal film is exposed.

20. The manufacturing method of the display device, according to claim 19, wherein the step (d) includes forming a plurality of contact holes for penetrating through the silicon oxide film on the oxide semiconductor layer, at same time, when to forma channel protective layer on the oxide semiconductor layer by patterning the silicon oxide film.

21. The manufacturing method of the display device, according to claim 19, wherein the first metal film is formed of any of or an alloy in combination with titanium, molybdenum, aluminum, chromium, copper, tungsten, zirconium, tantalum, silver, and manganese.

22. The manufacturing method of the display device, according to claim 19, wherein the second metal film, the third metal film, and the fourth metal film are formed of any of or an alloy in combination with titanium, molybdenum, aluminum, chromium, copper, tungsten, zirconium, tantalum, silver, and manganese.

23. The manufacturing method of the display device, according to claim 19, wherein the oxide semiconductor layer includes In—

Ga—

Zn—

O, In—

Al—

Zn—

O, In—

Sn—

Zn—

O, In—

Zn—

O, In—

Sn—

O, Zn—

O, and Sn—

O as a main component.

24. The manufacturing method of the display device, according to claim 19, wherein the metal oxide layer has a thickness 50 nm and 200 nm.

25. The manufacturing method of the display device, according to claim 19, wherein the substrate is a glass substrate, and a silicon nitride film is formed between the substrate and the gate electrode in a manner that the substrate and the gate electrode are not in direct contact with each other.

26. The manufacturing method of the display device, according to claim 19, wherein the metal oxide layer is a light shielding layer for shielding entrance of external light to the oxide semiconductor layer.

27. The manufacturing method of the display device, according to claim 19, wherein the display device is a liquid crystal display device in an FFS (Fringe Field Switching) mode for driving liquid crystal molecules using a fringe electric field.

28. The manufacturing method of the display device, according to claim 19, wherein the display device is an organic EL display device, in which organic light emitting diodes are used as light emitting devices.