LIQUID CRYSTAL DISPLAY DEVICE, EL DISPLAY DEVICE, AND MANUFACTURING METHOD THEREOF

• US 20130120702A1
• Filed: 11/02/2012
• Published: 05/16/2013
• Est. Priority Date: 11/11/2011
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Koyama, Jun
• Granted Patent: US 9,576,982 B2
• Time in Patent Office: Days
• US Class Current: 349/143
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer
• CPC Class Codes: G02F 1/136286 Wiring, e.g. gate line, drain line
• CPC Class Codes: G02F 1/13629 Multilayer wirings
• CPC Class Codes: G02F 1/136295 Materials; Compositions; Manufacture processes
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/123 pixel
• 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 27/124 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 27/1255 integrated with passive devices, e.g. auxiliary capacitors
• CPC Class Codes: H01L 27/1259 Multistep manufacturing methods
• CPC Class Codes: H01L 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• CPC Class Codes: H01L 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask

Abstract

A display device is manufactured with five photolithography steps: a step of forming a gate electrode, a step of forming a protective layer for reducing damage due to an etching step or the like, a step of forming a source electrode and a drain electrode, a step of forming a contact hole, and a step of forming a pixel electrode. The display device includes a groove portion which is formed in the step of forming the contact hole and separates the semiconductor layer.

Claims

1. A display device comprising:

a first wiring;

a semiconductor layer over the first wiring with a first insulating layer interposed therebetween;

a second insulating layer over and in contact with the semiconductor layer;

a second wiring over the second insulating layer, the second wiring electrically connected to the semiconductor layer through an opening formed in the second insulating layer; and

a pixel electrode electrically connected to the semiconductor layer,

wherein the second insulating layer and the semiconductor layer overlap with the first wiring, the second wiring, and the pixel electrode, and

wherein a groove portion is formed at least in the second insulating layer and the semiconductor layer to cross the first wiring.

2. The display device according to claim 1, wherein the semiconductor layer includes an oxide semiconductor.

3. The display device according to claim 1, further comprising:

a terminal portion outside a pixel portion that comprises the first wiring, the semiconductor layer, the first insulating layer, the second insulating layer, the second wiring, and the pixel electrode,

wherein, in the terminal portion, the semiconductor layer, the second insulating layer, and the second wiring are stacked in this order, and

wherein the terminal portion comprises an electrode over and electrically connected to the second wiring.

4. The display device according to claim 1, further comprising:

a third wiring electrically connected to the semiconductor layer through a second opening formed in the second insulating layer; and

a second pixel electrode electrically connected to the semiconductor layer through a third opening formed in the second insulating layer,

wherein the groove portion is formed between the first wiring and the third wiring, and

wherein the pixel electrode and the second pixel electrode are adjacent to each other with the third wiring provided therebetween.

5. A display device comprising:

a transistor including a gate electrode, a semiconductor layer, a protective layer, a first electrode, and a second electrode;

a first wiring electrically connected to the gate electrode;

a second wiring electrically connected to the first electrode;

a pixel electrode electrically connected to the second electrode;

a capacitor wiring; and

a groove portion,

wherein the protective layer is provided over and in contact with the semiconductor layer, and the semiconductor layer and the protective layer overlap with the first wiring, the second wiring, the pixel electrode, and the capacitor wiring,

wherein the first electrode and the second electrode are electrically connected to the semiconductor layer through first and second openings formed in the protective layer, respectively,

wherein the groove portion is formed to cross the first wiring in a line width direction of the first wiring and to cross the capacitor wiring in a line width direction of the capacitor wiring, and

wherein, in a direction parallel to a direction in which the second wiring extends, the groove portion is longer than the pixel electrode.

6. The display device according to claim 5,

wherein the semiconductor layer is not provided on a bottom surface of the groove portion.

7. The display device according to claim 5,

wherein the semiconductor layer is provided on a side surface of the groove portion.

8. The display device according to claim 5,

wherein the groove portion overlaps with an alignment film.

9. The display device according to claim 5,

wherein a second groove portion overlaps with the pixel electrode.

10. The display device according to claim 5,

wherein the semiconductor layer includes an oxide semiconductor.

11. The display device according to claim 5,

wherein the protective layer includes an oxide insulating material.

12. The display device according to claim 11,

wherein the oxide insulating material is a material in which, in an oxide containing indium, gallium, and zinc, part of the gallium is replaced with at least one element selected from titanium, zirconium, hafnium, and germanium.

13. The display device according to claim 5, wherein the display device is a liquid crystal display device.

14. A method for manufacturing a display device, comprising:

forming a gate electrode over a substrate by a first photolithography step;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer over the gate insulating layer;

forming a protective layer having at least first and second openings over the semiconductor layer by a second photolithography step;

forming a first electrode and a second electrode over the protective layer and in contact with the semiconductor layer through the first and the second openings by a third photolithography step;

forming an insulating layer over the first electrode and the second electrode;

forming an opening by selectively removing a part of the insulating layer which overlaps with the second electrode and a groove portion by removing a part of the insulating layer, a part of the semiconductor layer, and a part of the gate insulating layer by a fourth photolithography step; and

forming a pixel electrode over the insulating layer by a fifth photolithography step.

15. The method for manufacturing a display device, according to claim 14,

wherein a base layer is formed between the substrate and the gate electrode.

16. The method for manufacturing a display device, according to claim 14,

wherein the semiconductor layer includes an oxide semiconductor.

17. The method for manufacturing a display device, according to claim 14, further comprising:

after the formation of the protective layer, cleaning a surface of the semiconductor layer exposed in the openings.

18. The method for manufacturing a display device according to claim 14, wherein the display device is a liquid crystal display device.

19. A display device comprising:

a first transistor;

a second transistor;

a first wiring electrically connected to a gate electrode of the first transistor;

a second wiring electrically connected to one of a source electrode and a drain electrode of the first transistor;

a third wiring electrically connected to one of a source electrode and a drain electrode of the second transistor;

a fourth wiring electrically connecting the other of the source electrode and the drain electrode of the first transistor to a gate electrode of the second transistor;

a display element electrically connected to the other of the source electrode and the drain electrode of the second transistor;

a capacitor formed in a region where the other of the source electrode and the drain electrode of the first transistor overlaps with the third wiring; and

a groove portion,

wherein a protective layer is provided over and in contact with a semiconductor layer of the first and the second transistors,

wherein the semiconductor layer and the protective layer overlap with the first wiring, the second wiring, the third wiring, the fourth wiring, and the display element,

wherein the source electrodes and the drain electrodes of the first and the second transistors are electrically connected to the semiconductor layer through first, second, third, and fourth openings formed in the protective layer,

wherein the groove portion is formed to cross the first wiring in a line width direction of the first wiring, and

wherein the groove portion is formed to cross the gate electrode of the second transistor in a line width direction of the gate electrode of the second transistor in a direction parallel to a direction in which the second wiring and the third wiring extend.

20. The display device according to claim 19,

wherein the semiconductor layer is not provided on a bottom surface of the groove portion.

21. The display device according to claim 19,

wherein the semiconductor layer is provided on a side surface of the groove portion.

22. The display device according to claim 19,

wherein the groove portion overlaps with a partition layer.

23. The display device according to claim 19,

wherein one electrode of the display element and the fourth wiring are formed from a same layer.

24. The display device according to claim 19,

wherein the semiconductor layer includes an oxide semiconductor.

25. The display device according to claim 19,

wherein the protective layer includes an oxide insulating material.

26. The display device according to claim 25,

wherein the oxide insulating material is a material in which, in an oxide containing indium, gallium, and zinc, part of the gallium is replaced with at least one element selected from titanium, zirconium, hafnium, and germanium.

27. The display device according to claim 19, wherein the display device is an EL display device, and the display element is an EL element.

28. A method for manufacturing a display device, comprising:

forming a gate electrode over a substrate by a first photolithography step;

forming a gate insulating layer over the gate electrode;

forming a semiconductor layer over the gate insulating layer;

forming a protective layer having at least first and second openings over the semiconductor layer by a second photolithography step;

forming a source electrode and a drain electrode over the protective layer and in contact with the semiconductor layer through the first and the second openings by a third photolithography step;

forming an insulating layer over the source electrode and the drain electrode;

forming an opening by selectively removing a part of the insulating layer and a groove portion by removing a part of the insulating layer, a part of the semiconductor layer, and a part of the gate insulating layer by a fourth photolithography step;

forming an electrode of an EL element over the insulating layer and the opening in the insulating layer by a fifth photolithography step; and

forming a partition layer for separately coloring EL layers of EL elements with corresponding colors over the insulating layer and a part of the electrode of the EL element by a sixth photolithography step.

29. The method for manufacturing a display device, according to claim 28,

wherein a base layer is formed between the substrate and the gate electrode.

30. The method for manufacturing a display device, according to claim 28,

wherein the semiconductor layer includes an oxide semiconductor.

31. The method for manufacturing a display device, according to claim 28, further comprising:

after the formation of the protective layer, cleaning a surface of the semiconductor layer exposed in the openings.