SEMICONDUCTOR DEVICE AND METHOD OF FABRICATING THE SAME

• US 20090040445A1
• Filed: 04/10/2008
• Published: 02/12/2009
• Est. Priority Date: 07/06/1999
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: GOTO, Yuugo, KOBAYASHI, Yuko, HIRAKATA, Yoshiharu, YAMAZAKI, Shunpei
• Granted Patent: US 7,808,009 B2
• Time in Patent Office: Days
• US Class Current: 349/123
• CPC Class Codes: G02F 1/13306 Circuit arrangements or driving methods for the control of single liquid crystal cells G02F1/132, G02F1/133382 take precedence
• 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 1/13338 Input devices, e.g. touch panels
• CPC Class Codes: G02F 1/133512 Light shielding layers, e.g. black matrix G02F1/136209 takes precedence
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/1341 Filling or closing of cells
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/13454 Drivers integrated on the active matrix substrate G02F1/136277 takes precedence
• CPC Class Codes: G02F 1/1368 in which the switching element is a three-electrode device G02F1/136277 takes precedence
• CPC Class Codes: H01L 2029/7863 with an LDD consisting of more than one lightly doped zone or having a non-homogeneous dopant distribution, e.g. graded LDD
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1214 comprising a plurality of TFTs formed on a non-semiconducting substrate, e.g. driving circuits for AMLCDs
• CPC Class Codes: H01L 27/1222 with a particular composition, shape or crystalline structure of the active layer
• 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 27/1288 employing particular masking sequences or specially adapted masks, e.g. half-tone mask
• CPC Class Codes: H01L 29/167 further characterised by the doping material H01L29/1604 takes precedence
• CPC Class Codes: H01L 29/78621 with LDD structure or an extension or an offset region or characterised by the doping profile
• CPC Class Codes: H01L 29/78627 with a significant overlap between the lightly doped drain and the gate electrode, e.g. GOLDD
• CPC Class Codes: H01L 29/78669 with inverted-type structure, e.g. with bottom gate
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 : Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: Y10S 438/924 : To facilitate selective etching
• CPC Class Codes: Y10S 438/98 : Utilizing process equivalents or options

Abstract

There is provided a high quality liquid crystal panel having a thickness with high accuracy, which is designed, without using a particulate spacer, within a free range in accordance with characteristics of a used liquid crystal and a driving method, and is also provided a method of fabricating the same. The shape of a spacer for keeping a substrate interval constant is made such that it is a columnar shape, a radius R of curvature is 2 μm or less, a height H is 0.5 μm to 10 μm, a diameter is 20 μm or less, and an angle α is 65° to 115°. By doing so, it is possible to prevent the lowering of an opening rate and the lowering of light leakage due to orientation disturbance.

Claims

1. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a plurality of spacers formed over the second substrate;

a second alignment film formed on the plurality of spacers and formed over the second substrate; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end,

wherein L₂ is a width obtained by adding a thickness of the second alignment film to the second end of one of the plurality of spacers,

wherein L₁ is a width obtained by adding the thickness of the second alignment film to a width at half of height of the one of the plurality of spacers,

wherein the L₁ and the L₂ are set in a range of 0.8<

L₂/L₁<

3, and

wherein a radius of curvature of an edge between a upper surface and a side surface of each of the plurality of spacers is 2 μ

m or less.

2. The display device according to claim 1,

wherein the plurality of spacers is disposed regularly.

3. The display device according to claim 1,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

4. The display device according to claim 1,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

5. The display device according to claim 1,

wherein the width of the center portion is 20 μ

m or less

6. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a second alignment film formed over the second substrate;

a plurality of spacers formed on the second alignment film; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end,

wherein L₂ is a width of the second end of one of the plurality of spacers,

wherein L₁ is a width at half of height of the one of the plurality of spacers, and

wherein the L₁ and the L₂ are set in a range of 1<

L₂/L₁<

1.1.

7. The display device according to claim 6,

wherein the plurality of spacers is disposed regularly.

8. The display device according to claim 6,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

9. The display device according to claim 6,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

10. The display device according to claim 6,

wherein the width of the center portion is 20 μ

m or less

11. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a second alignment film formed over the second substrate;

a plurality of spacers formed on the second alignment film; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end,

wherein L₂ is a width of the second end of one of the plurality of spacers,

wherein L₁ is a width at half of height of the one of the plurality of spacers,

wherein the L₁ and the L₂ are set in a range of 1<

L₂/L₁<

1.1, and

wherein an angle between a tangent plane at the center portion and a surface of the second substrate is 65°

to 115°

.

12. The display device according to claim 11,

wherein the plurality of spacers is disposed regularly.

13. The display device according to claim 11,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

14. The display device according to claim 11,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

15. The display device according to claim 11,

wherein the width of the center portion is 20 μ

m or less

16. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a second alignment film formed over the second substrate;

a plurality of spacers formed on the second alignment film; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end,

wherein L₂ is a width of the second end of one of the plurality of spacers,

wherein L₁ is a width at half of height of the one of the plurality of spacers,

wherein the L₁ and the L₂ are set in a range of 1<

L₂/L₁<

1.1, and

wherein the height of the one of the plurality of spacers is 0.5 μ

m to 10 μ

m.

17. The display device according to claim 16,

wherein the plurality of spacers is disposed regularly.

18. The display device according to claim 16,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

19. The display device according to claim 16,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

20. The display device according to claim 16,

wherein the width of the center portion is 20 μ

m or less

21. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a second alignment film formed over the second substrate;

a plurality of spacers formed on the second alignment film; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end,

wherein L₂ is a width of the second end of one of the plurality of spacers,

wherein L₁ is a width at half of height of the one of the plurality of spacers,

wherein the L₁ and the L₂ are set in a range of 1<

L₂/L₁<

1.1, and

wherein a radius of curvature of an edge between a upper surface and a side surface of each of the plurality of spacers is 2 μ

m or less.

22. The display device according to claim 21,

wherein the plurality of spacers is disposed regularly.

23. The display device according to claim 21,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

24. The display device according to claim 21,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

25. The display device according to claim 21,

wherein the width of the center portion is 20 μ

m or less

26. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a second alignment film formed over the second substrate;

a plurality of spacers formed on the second alignment film; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end,

wherein L₂ is a width of the second end of one of the plurality of spacers,

wherein L₁ is a width at half of height of the one of the plurality of spacers,

wherein the L₁ and the L₂ are set in a range of 1<

L₂/L₁<

1.1, and

wherein each of the plurality of spacers comprises resin material.

27. The display device according to claim 26,

wherein the plurality of spacers is disposed regularly.

28. The display device according to claim 26,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

29. The display device according to claim 26,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

30. The display device according to claim 26,

wherein the width of the center portion is 20 μ

m or less.

31. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a plurality of spacers formed on the first alignment film;

a second substrate opposed to the first substrate;

a second alignment film formed over the second substrate; and

wherein each of the plurality of spacers has a first end, a second end between the first end and the first substrate, and a center portion between the first end and the second end,

wherein L₂ is a width of the second end of one of the plurality of spacers,

wherein L₁ is a width at half of height of the one of the plurality of spacers, and

wherein the L₁ and the L₂ are set in a range of 1<

L₂/L₁<

1.1.

32. The display device according to claim 31,

wherein the plurality of spacers is disposed regularly.

33. The display device according to claim 31,

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

34. The display device according to claim 31,

wherein the plurality of spacers is disposed at a density of 10 to 200 ones per mm².

35. The display device according to claim 31,

wherein the width of the center portion is 20 μ

m or less.

36. A display device comprising:

a first substrate;

a plurality of pixels arranged in a matrix, each of which comprises a thin film transistor formed over the first substrate;

an interlayer insulating film formed over the thin film transistor;

a first alignment film formed over the interlayer insulating film;

a second substrate opposed to the first substrate;

a plurality of spacers formed over the second substrate;

a second alignment film formed on the plurality of spacers and formed over the second substrate; and

a liquid crystal material interposed between the first alignment film and the second alignment film;

wherein each of the plurality of spacers has a first end, a second end between the first end and the second substrate, and a center portion between the first end and the second end, and

wherein each of the plurality of spacers is disposed for every six pixels of the plurality of the pixels.

37. The display device according to claim 36,

wherein an angle between a tangent plane at the center portion and a surface of the second substrate is 65°

to 115°

.

38. The display device according to claim 36,

wherein a height of at least one of the plurality of spacers is 0.5 μ

m to 10 μ

m.

39. The display device according to claim 36,

wherein a radius of curvature of an edge between a upper surface and a side surface of each of the plurality of spacers is 2 μ

m or less.

40. The display device according to claim 36,

wherein each of the plurality of spacers comprises resin material.