Liquid crystal display device having color organic film as the interlayer insulator

• US 6,118,505 A
• Filed: 01/15/1998
• Issued: 09/12/2000
• Est. Priority Date: 01/21/1997
• Status: Expired due to Term

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tanaka, Keiichi, Jogan, Shingo, Nagata, Hisashi
• Primary Examiner(s): Dudek, James A.
• Application Number:
  US09/007,536
• Time in Patent Office: 971 Days
• Field of Search: 349/106, 349/39, 359/891
• US Class Current: 349/106
• CPC Class Codes: G02F 1/133357 Planarisation layers
• 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 1/136213 Storage capacitors associated with the pixel electrode
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G02F 1/136227 Through-hole connection of the pixel electrode to the active element through an insulation layer

Abstract

A method for fabricating a liquid crystal display device is provided. The liquid crystal display device includes an active matrix substrate, a counter substrate disposed to face the active matrix substrate, and a liquid crystal layer interposed between the active matrix substrate and the counter substrate. The active matrix substrate includes: gate signal lines for supplying control signals and source signal lines for supplying video signals formed to cross each other; switching elements formed at crossings of the gate signal lines and the source signal lines in a matrix, the switching elements being connected to the gate signal lines and the source signal lines; an interlayer insulating film formed on the resultant active matrix substrate; and pixel electrodes formed on the interlayer insulating film in a matrix, wherein a color organic film is used as the interlayer insulating film, and laminated to the resultant active matrix substrate.

Claims

1. A method for fabricating a liquid crystal display device including an active matrix substrate, a counter substrate disposed to face the active matrix substrate, and a liquid crystal layer interposed between the active matrix substrate and the counter substrate, the active matrix substrate including:

gate signal lines for supplying control signals and source signal lines for supplying video signals formed so as to cross each other;

switching elements formed at crossings of the gate signal lines and the source signal lines in a matrix, the switching elements being connected to the gate signal lines and the source signal lines;

an interlayer insulating film formed on the resultant active matrix substrate;

and pixel electrodes formed on the interlayer insulating film in a matrix,

wherein a color organic film is used as the interlayer insulating film, and the color organic film is laminated to the resultant active matrix substrate.

2. A method for fabricating a liquid crystal display device according to claim 1, wherein the color organic film is photosensitive, and

after the color organic film is laminated, the color organic film is patterned by light exposure and development.

3. A method for fabricating a liquid crystal display device according to claim 1, wherein after the color organic film is laminated, a photoresist is formed, exposed to light, and developed, to pattern the color organic film by etching.

4. A method for fabricating a liquid crystal display device according to claim 1, wherein the color organic film is composed of primary color film pieces arranged in a matrix, and

the primary color film pieces are obtained by laminating transparent organic films colored with the respective primary colors and then patterning the transparent organic films.

5. A method for fabricating a liquid crystal display device according to claim 4, wherein ends of adjacent primary color film pieces are overlapped with each other.

6. A method for fabricating a liquid crystal display device according to claim 1, wherein the color organic film further includes light-shading film pieces, and

the light-shading film pieces are obtained by laminating a light-shading organic film and then patterning the light-shading organic film.

7. A method for fabricating a liquid crystal display device according to claim 6, wherein in order to form the light-shading film pieces, the laminated light-shading organic film is subjected to pattern exposure from a top surface of the active matrix substrate and overall exposure from a bottom surface of the active matrix substrate.

8. A method for fabricating a liquid crystal display device according to claim 6, wherein the light-shading film pieces are disposed above the source signal lines.

9. A method for fabricating a liquid crystal display device according to claim 8, wherein the source signal lines are made of a transparent conductive film, and

the light-shading film pieces are disposed above the source signal lines by laminating the light-shading organic film on the resultant active matrix substrate and allowing the light-shading organic film to be subjected to overall exposure from a bottom surface of the active matrix substrate.

10. A method for fabricating a liquid crystal display device according to claim 1, wherein the interlayer insulating film is composed of a color organic film and a photosensitive overcoat film, and

the overcoat film is laminated to the color organic film and then patterned by light exposure and development.

11. A method for fabricating a liquid crystal display device according to claim 10, wherein after the formation of the color organic film and the overcoat film, a photoresist is formed, exposed to light, and developed, to etch the color organic film and the overcoat film, so as to form contact holes.

12. A method for fabricating a liquid crystal display device according to claim 10, wherein after the formation of the color organic film and the overcoat film, baking is performed, and then a photoresist is formed, exposed to light, and developed, to etch the color organic film and the overcoat film, so as to form contact holes.

13. A method for fabricating a liquid crystal display device according to claim 1, wherein the interlayer insulating film is composed of a color organic film and a photosensitive overcoat film, and

the overcoat film is laminated to the color organic film, and then a photoresist is formed, exposed to light, and developed, to pattern the overcoat film by etching.

14. A method for fabricating a liquid crystal display device according to claim 13, wherein after the formation of the color organic film and the overcoat film, a photoresist is formed, exposed to light, and developed, to etch the color organic film and the overcoat film, so as to form contact holes.

15. A method for fabricating a liquid crystal display device according to claim 13, wherein after the formation of the color organic film and the overcoat film, baking is performed, and then a photoresist is formed, exposed to light, and developed, to etch the color organic film and the overcoat film, so as to form contact holes.

16. A liquid crystal display device comprising an active matrix substrate, a counter substrate disposed to face the active matrix substrate, and a liquid crystal layer interposed between the active matrix substrate and the counter substrate, the active matrix substrate including:

gate signal lines for supplying control signals and source signal lines for supplying video signals formed so as to cross each other;

switching elements formed at crossings of the gate signal lines and the source signal lines in a matrix, the switching elements being connected to the gate signal lines and the source signal lines;

an interlayer insulating film formed on the resultant active matrix substrate;

and pixel electrodes formed on the interlayer insulating film in a matrix,

wherein a laminated color organic film is used as the interlayer insulating film.

17. A liquid crystal display device according to claim 16, wherein the interlayer insulating film further includes an overcoat film.

18. A liquid crystal display device according to claim 16, wherein contact holes are formed through the interlayer insulating film, and the pixel electrodes are connected to the switching elements via the contact holes.

19. A liquid crystal display device according to claim 18, further including storage capacitance electrodes, wherein a storage capacitance obtained by each of the storage capacitance electrodes is connected in parallel with a pixel capacitance obtained by the pixel electrode, and

each contact hole overlaps the storage capacitance electrode.

20. A liquid crystal display device according to claim 19, wherein each contact hole completely overlaps the storage capacitance electrode.

21. A liquid crystal display device according to claim 18, wherein the taper angle of the contact hole is 45°

or less with respect to a line normal to the substrate.

22. A liquid crystal display device according to claim 17, wherein contact holes are formed through the interlayer insulating film, and the pixel electrodes are connected to the switching elements via the contact holes, and

an inner wall of each of the contact holes is covered with the overcoat film.

23. A liquid crystal display device according to claim 17, wherein contact holes are formed through the interlayer insulating film, and the pixel electrodes are connected to the switching elements via the contact holes, and

an inner wall of each of the contact holes includes an exposed face of the color organic film and an exposed face of the overcoat film.

24. A liquid crystal display device according to claim 16, wherein each of the pixel electrodes overlaps the corresponding source signal line by an overlap width of 1 μ

m or more, and

when the video signals with one polarity on the source signal lines are supplied to one row of switching elements lined along one gate signal line, the video signals on the source signal lines are supplied to the next row of switching elements lined along the next gate line by inverting the polarity, and this is repeated for the remaining gate signal lines.

25. A liquid crystal display device according to claim 16, further including storage capacitance electrodes, wherein a storage capacitance obtained by each of the storage capacitance electrodes is connected in parallel with a pixel capacitance obtained by the pixel electrode, and

the ratio of a capacitance between the pixel electrode and the source signal line to a sum of the pixel capacitance obtained by the pixel electrode and the storage capacitance obtained by the storage capacitance electrode is 10% or less.

26. A liquid crystal display device according to claim 16, wherein the thickness of the interlayer insulating film is 2 μ

m or more.

27. A liquid crystal display device according to claim 17, wherein the thickness of the interlayer insulating film is 2 μ

m or more.