Liquid crystal display device and touch panel

• US 10,007,133 B2
• Filed: 02/21/2017
• Issued: 06/26/2018
• Est. Priority Date: 10/12/2012
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei, Hirakata, Yoshiharu, Kubota, Daisuke, Yamashita, Akio
• Primary Examiner(s): Duong, Thoi
• Application Number:
  US15/437,599
• Publication Number:
  US 20170160573A1
• Time in Patent Office: 490 Days
• Field of Search: 349153, 349 43, 349 12, 349138, 349139, 349158, 349187, 349193, 349 42, 438 30, 438104, 438151, 438158, 438677, 438 99, 257 43, 257E23008, 257E29273, 257 40
• CPC Class Codes: G02F 1/1333 Constructional arrangements; Manufacturing methodsG02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/133305 Flexible substrates, e.g. plastics, organic film
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/1341 Filling or closing of cells
• CPC Class Codes: G02F 1/13415 Drop filling process
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: G02F 2201/121 common or background
• CPC Class Codes: G02F 2201/123 pixel
• CPC Class Codes: G02F 2202/10 semiconductor
• CPC Class Codes: G06F 2203/04103 Manufacturing, i.e. details related to manufacturing processes specially suited for touch sensitive devices
• CPC Class Codes: G06F 3/0412 Digitisers structurally integrated in a display
• CPC Class Codes: G06F 3/0443 using a single layer of sensing electrodes
• CPC Class Codes: G06F 3/0445 using two or more layers of sensing electrodes, e.g. using two layers of electrodes separated by a dielectric layer
• CPC Class Codes: G06F 3/0446 using a grid-like structure of electrodes in at least two directions, e.g. using row and column electrodes
• 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 29/045 by their particular orientation of crystalline planes
• 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: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

To provide a highly reliable liquid crystal display device including flexible substrates and a crystalline oxide semiconductor film for a backplane. The device includes a flexible first substrate, a flexible second substrate facing the first substrate, and a liquid crystal layer sealed between the substrates with a sealing member. The first substrate is provided with a layer including a transistor, an organic resin film over the transistor, a pixel electrode and a common electrode over the organic resin film, which partly overlap with each other with an insulating film provided therebetween, and an alignment film thereover. The transistor includes a crystalline oxide semiconductor film as a semiconductor layer where a channel is formed. Drying treatment is performed on the layer before the liquid crystal layer is sealed between the substrates, and steps from the drying treatment to sealing of the liquid crystal layer are performed without exposure to the air.

Claims

1. A method for manufacturing a liquid crystal display device comprising the steps of:

forming a transistor over a first substrate, the transistor comprising an oxide semiconductor film which includes a channel formation region;

forming an insulating film over the transistor;

forming a pixel electrode over the insulating film, the pixel electrode being in electrical contact with the transistor;

heating the first substrate and a second substrate to perform dry treatment after forming the pixel electrode;

dropping a liquid crystal material on the second substrate after heating the second substrate; and

bonding the first substrate and the second substrate with each other with the liquid crystal material interposed therebetween,

wherein the steps of heating the first substrate and the second substrate, and dropping the liquid crystal material are successively performed without exposure to air.

2. The method for manufacturing a liquid crystal display device according to claim 1, further comprising the step of:

forming a ceramic layer over at least one of a pair of flat surfaces of the first substrate and the second substrate.

3. The method for manufacturing a liquid crystal display device according to claim 1, further comprising the step of:

forming a ceramic layer over at least one of a pair of flat surfaces of the first substrate and the second substrate,

wherein the ceramic layer comprises one of a metal oxide, a metal nitride, a metal carbide, a metal arsenide, a metal sulphide, a silicon oxide, and a silicon carbide and has a property of transmitting visible light.

4. The method for manufacturing a liquid crystal display device according to claim 1, wherein the step of heating the first substrate and the second substrate is performed at a temperature higher than or equal to 100°

C.

5. The method for manufacturing a liquid crystal display device according to claim 1, wherein the step of bonding is performed in an atmosphere at a dew point of lower than or equal to −

60°

C.

6. The method for manufacturing a liquid crystal display device according to claim 1, wherein the oxide semiconductor film comprises indium, gallium, and zinc.

7. The method for manufacturing a liquid crystal display device according to claim 1, wherein the oxide semiconductor film comprises a crystal part.

8. The method for manufacturing a liquid crystal display device according to claim 1,

wherein the oxide semiconductor film comprises a crystal part, and

wherein a c-axis of a crystal in the crystal part is aligned in a direction substantially perpendicular to a top surface of the oxide semiconductor film.

9. A method for manufacturing a liquid crystal display device comprising the steps of:

forming a transistor over a first substrate, the transistor comprising an oxide semiconductor film which includes a channel formation region;

forming an insulating film over the transistor;

forming a pixel electrode over the insulating film, the pixel electrode being in electrical contact with the transistor;

heating the first substrate and a second substrate under reduced pressure to perform dry treatment after forming the pixel electrode;

dropping a liquid crystal material on the second substrate after heating the second substrate; and

bonding the first substrate and the second substrate with each other with the liquid crystal material interposed therebetween,

wherein the steps of heating the first substrate and the second substrate, and dropping the liquid crystal material are successively performed without exposure to air.

10. The method for manufacturing a liquid crystal display device according to claim 9, further comprising the step of:

forming a ceramic layer over at least one of a pair of flat surfaces of the first substrate and the second substrate.

11. The method for manufacturing a liquid crystal display device according to claim 9, further comprising the step of:

forming a ceramic layer over at least one of a pair of flat surfaces of the first substrate and the second substrate,

wherein the ceramic layer comprises one of a metal oxide, a metal nitride, a metal carbide, a metal arsenide, a metal sulphide, a silicon oxide, and a silicon carbide and has a property of transmitting visible light.

12. The method for manufacturing a liquid crystal display device according to claim 9, wherein the step of heating the first substrate and the second substrate is performed at a temperature higher than or equal to 100°

C.

13. The method for manufacturing a liquid crystal display device according to claim 9, wherein the step of bonding is performed in an atmosphere at a dew point of lower than or equal to −

60°

C.

14. The method for manufacturing a liquid crystal display device according to claim 9, wherein the oxide semiconductor film comprises indium, gallium, and zinc.

15. The method for manufacturing a liquid crystal display device according to claim 9, wherein the oxide semiconductor film comprises a crystal part.

16. The method for manufacturing a liquid crystal display device according to claim 9,

wherein the oxide semiconductor film comprises a crystal part, and

wherein a c-axis of a crystal in the crystal part is aligned in a direction substantially perpendicular to a top surface of the oxide semiconductor film.

17. A method for manufacturing a liquid crystal display device comprising the steps of:

forming a transistor over a first substrate, the transistor comprising an oxide semiconductor film which includes a channel formation region;

forming an insulating film over the transistor;

forming a pixel electrode over the insulating film, the pixel electrode being in electrical contact with the transistor;

heating the first substrate to perform dry treatment after forming the pixel electrode;

heating a second substrate to perform dry treatment;

dropping a liquid crystal material on the second substrate after heating the second substrate; and

bonding the first substrate and the second substrate with each other with the liquid crystal material interposed therebetween,

wherein the steps of heating the first substrate and the second substrate, and dropping the liquid crystal material are successively performed without exposure to air.

18. The method for manufacturing a liquid crystal display device according to claim 17, further comprising the step of:

forming a ceramic layer over at least one of a pair of flat surfaces of the first substrate and the second substrate.

19. The method for manufacturing a liquid crystal display device according to claim 17, further comprising the step of:

forming a ceramic layer over at least one of a pair of flat surfaces of the first substrate and the second substrate,

wherein the ceramic layer comprises one of a metal oxide, a metal nitride, a metal carbide, a metal arsenide, a metal sulphide, a silicon oxide, and a silicon carbide and has a property of transmitting visible light.

20. The method for manufacturing a liquid crystal display device according to claim 17,

wherein the step of heating the first substrate is formed at a temperature higher than or equal to 100°

C., and

wherein the step of heating the second substrate is performed at a temperature higher than or equal to 100°

C.

21. The method for manufacturing a liquid crystal display device according to claim 17, wherein the step of bonding is performed in an atmosphere at a dew point of lower than or equal to −

60°

C.

22. The method for manufacturing a liquid crystal display device according to claim 17, wherein the oxide semiconductor film comprises indium, gallium, and zinc.

23. The method for manufacturing a liquid crystal display device according to claim 17, wherein the oxide semiconductor film comprises a crystal part.

24. The method for manufacturing a liquid crystal display device according to claim 17,

wherein the oxide semiconductor film comprises a crystal part, and

wherein a c-axis of a crystal in the crystal part is aligned in a direction substantially perpendicular to a top surface of the oxide semiconductor film.