Light emitting apparatus and method of fabricating the same Number:7,402,945 from the United States Patent and Trademark Office (PTO) owispatent

Title: Light emitting apparatus and method of fabricating the same

Abstract: Although an ink jet method known as a method of selectively forming a film of a high molecular species organic compound, can coat to divide an organic compound for emitting three kinds (R, G, B) of light in one step, film forming accuracy is poor, it is difficult to control the method and therefore, uniformity is not achieved and the constitution is liable to disperse. In contrast thereto, according to the invention, a film comprising a high molecular species material is formed over an entire face of a lower electrode connected to a thin film transistor by a coating method and thereafter, the film comprising the high molecular species material is etched by etching by plasma to thereby enable to selectively form a high molecular species material layer. Further, the organic compound layer is constituted by a material for carrying out luminescence of white color or luminescence of single color and combined with a color changing layer or a coloring layer to thereby realize full color formation.

Patent Number: 7,402,945 Issued on 07/22/2008 to Yamazaki,   et al.

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Inventors:	Yamazaki; Shunpei (Tokyo, JP), Murakami; Masakazu (Kanagawa, JP), Seo; Satoshi (Kanagawa, JP)
Assignee:	Semiconductor Energy Laboratory Co., Ltd. (JP)
Appl. No.:	10/379,123
Filed:	March 4, 2003

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Foreign Application Priority Data

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Mar 07, 2002 [JP]			2002-062763

Current U.S. Class:	313/504 ; 313/503; 313/506; 313/509; 428/690
Current International Class:	H05B 33/22 (20060101); H05B 33/00 (20060101)
Field of Search:	313/503,504,506,509,511,512

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References Cited [Referenced By]

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Primary Examiner: Santiago; Mariceli
Attorney, Agent or Firm: Cook, Alex, McFarron, Manzo, Cummings & Mehler, Ltd.

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Claims

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What is claimed is:

1. A light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, said pixel portion having a plurality of luminescent elements over a first substrate having an insulating surface: wherein each of said plurality of luminescent elements comprises a first electrode, a layer comprising an organic compound over the first electrode, and a second electrode over the layer comprising the organic compound; wherein an end portion of the first electrode is covered by an insulating substance, a side face of the insulating substance including a curved face having a first radius of curvature and a curved face having a second radius of curvature; wherein the layer comprising the organic compound is provided over the insulating substance and the first electrode; and wherein a third electrode is in contact with the insulating substance.

2. The light emitting apparatus according to claim 1, wherein a second substrate having a light transmitting performance is over said plurality of luminescent elements.

3. The light emitting apparatus according to claim 2, wherein said layer comprising said organic compound comprises a material which is luminescent in white color and combined with a color filter provided at the second substrate.

4. The light emitting apparatus according to claim 2, wherein said layer comprising said organic compound comprises a material of emitting light of a single color and combined with at least a color changing layer and a coloring layer provided at the second substrate.

5. The light emitting apparatus according to claim 2, wherein an interval between the first substrate and the second substrate is in a range of 2 .mu.m through 30 .mu.m.

6. The light emitting apparatus according to claim 2, wherein a light emitted from each of said plurality of luminescent elements transmits through said second substrate.

7. The light emitting apparatus according to claim 1, wherein the layer comprising the organic compound comprises a polymer.

8. The light emitting apparatus according to claim 1, wherein said layer comprising said organic compound is a laminated layer of a layer comprising a polymer and a layer comprising a low molecular material.

9. The light emitting apparatus according to claim 1, wherein an upper end portion of the insulating substance is the curved face having the first radius of curvature, a lower end portion of the insulating substance is the curved face having the second radius of curvature, and the first radius of curvature and the second radius of curvature is in a range of 0.2 .mu.m through 3 .mu.m.

10. The light emitting apparatus according to claim 1, wherein a second substrate is over said plurality of luminescent elements; and wherein the second substrate includes a recessed portion and a drying agent is provided at the recessed portion.

11. The light emitting apparatus according to claim 1, wherein a second substrate is over said plurality of luminescent elements; and wherein the second substrate includes a recessed portion provided with a drying agent and the recessed portion overlaps the drive circuit provided over the first substrate.

12. The light emitting apparatus according to claim 1, wherein said layer comprising said organic compound comprises poly(ethylenedioxythiophene)/poly(stylenesulfonic acid).

13. The light emitting apparatus according to claim 1, wherein the light emitting apparatus is selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation apparatus, a personal computer and a portable information terminal.

14. A light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, said pixel portion having a plurality of luminescent elements over a first substrate having an insulating surface: wherein each of said plurality of luminescent elements comprises a first electrode, a layer comprising an organic compound over the first electrode, and a second electrode over the layer comprising the organic compound; wherein an end portion of the first electrode is covered by an insulating substance, a side face of the insulating substance including a curved face having a first radius of curvature and a curved face having a second radius of curvature; wherein a third electrode is provided over the insulating substance; and wherein the layer comprising the organic compound is provided over the insulating substance and the first electrode.

15. The light emitting apparatus according to claim 14, wherein a second substrate having a light transmitting performance is over said plurality of luminescent elements.

16. The light emitting apparatus according to claim 15, wherein said layer comprising said organic compound comprises a material which is luminescent in white color and combined with a color filter provided at the second substrate.

17. The light emitting apparatus according to claim 15, wherein said layer comprising said organic compound comprises a material of emitting light of a single color and combined with at least a color changing layer and a coloring layer provided at the second substrate.

18. The light emitting apparatus according to claim 15, wherein an interval between the first substrate and the second substrate is in a range of 2 .mu.m through 30 .mu.m.

19. The light emitting apparatus according to claim 15, wherein a light emitted from each of said plurality of luminescent elements transmits through said second substrate.

20. The light emitting apparatus according to claim 14, wherein the layer comprising the organic compound comprises a polymer.

21. The light emitting apparatus according to claim 14, wherein said layer comprising said organic compound is a laminated layer of a layer comprising a polymer and a layer comprising a low molecular material.

22. The light emitting apparatus according to claim 14, wherein an upper end portion of the insulating substance is the curved face having the first radius of curvature, a lower end portion of the insulating substance is the curved face having the second radius of curvature, and the first radius of curvature and the second radius of curvature is in a range of 0.2 .mu.m through 3 .mu.m.

23. The light emitting apparatus according to claim 14, wherein a second substrate is over said plurality of luminescent elements; and wherein the second substrate includes a recessed portion and a drying agent is provided at the recessed portion.

24. The light emitting apparatus according to claim 14, wherein a second substrate is over said plurality of luminescent elements; and wherein the second substrate includes a recessed portion provided with a drying agent and the recessed portion overlaps the drive circuit provided over the first substrate.

25. The light emitting apparatus according to claim 14, wherein said layer comprising said organic compound comprises poly(ethylenedioxythiophene)/poly(stylenesulfonic acid).

26. The light emitting apparatus according to claim 14, wherein the light emitting apparatus is selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation apparatus, a personal computer and a portable information terminal.

27. A light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, said pixel portion having a plurality of luminescent elements over a first substrate having an insulating surface: wherein each of said plurality of luminescent elements comprises a first electrode, a layer comprising an organic compound over the first electrode, and a second electrode over the layer comprising the organic compound; wherein an end portion of the first electrode is covered by an insulating substance, a side face of the insulating substance including a curved face having a first radius of curvature and a curved face having a second radius of curvature; wherein the layer comprising the organic compound is provided over the insulating substance and the first electrode; and wherein a part of the layer comprising the organic compound is in contact with the insulating substance.

28. The light emitting apparatus according to claim 27, wherein a second substrate having a light transmitting performance is over said plurality of luminescent elements.

29. The light emitting apparatus according to claim 28, wherein said layer comprising said organic compound comprises a material which is luminescent in white color and combined with a color filter provided at the second substrate.

30. The light emitting apparatus according to claim 28, wherein said layer comprising said organic compound comprises a material of emitting light of a single color and combined with at least a color changing layer and a coloring layer provided at the second substrate.

31. The light emitting apparatus according to claim 28, wherein an interval between the first substrate and the second substrate is in a range of 2.mu.m through 30.mu.m.

32. The light emitting apparatus according to claim 28, wherein a light emitted from each of said plurality of luminescent elements transmits through said second substrate.

33. The light emitting apparatus according to claim 27, wherein the layer comprising the organic compound comprises a polymer.

34. The light emitting apparatus according to claim 27, wherein said layer comprising said organic compound is a laminated layer of a layer comprising a polymer and a layer comprising a low molecular material.

35. The light emitting apparatus according to claim 27, wherein an upper end portion of the insulating substance is the curved face having the first radius of curvature, a lower end portion of the insulating substance is the curved face having the second radius of curvature, and the first radius of curvature and the second radius of curvature is in a range of 0.2.mu.m through 3.mu.m.

36. The light emitting apparatus according to claim 27, wherein a second substrate is over said plurality of luminescent elements; and wherein the second substrate includes a recessed portion and a drying agent is provided at the recessed portion.

37. The light emitting apparatus according to claim 27, wherein a second substrate is over said plurality of luminescent elements; and wherein the second substrate includes a recessed portion provided with a drying agent and the recessed portion overlaps the drive circuit provided over the first substrate.

38. The light emitting apparatus according to claim 27, wherein said layer comprising said organic compound comprises poly(ethylenedioxythiophene)/poly(stylenesulfonic acid).

39. The light emitting apparatus according to claim 27, wherein the light emitting apparatus is selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation apparatus, a personal computer and a portable information terminal.

40. A light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, the pixel portion comprising a first luminescent element and a second luminescent element over a substrate, wherein the first luminescent element comprises a first electrode, a first layer comprising an organic compound over the first electrode, and a part of a second electrode over the first layer comprising the organic compound, wherein the second luminescent element comprises a fourth electrode, a second layer comprising an organic compound over the fourth electrode, and a part of the second electrode over the second layer comprising the organic compound, wherein an insulating substance are over an end portion of the first electrode and an end portion of the fourth electrode, wherein upper and lower end portions of a side face of the insulating substance are round, and wherein a third electrode is between the first and second luminescent elements.

41. The light emitting apparatus according to claim 40, wherein the second electrode comprises Mg and Ag.

42. The light emitting apparatus according to claim 40, wherein the third electrode is above the first electrode.

43. The light emitting apparatus according to claim 40, wherein the third electrode is not connected to the first electrode.

44. The light emitting apparatus according to claim 40, wherein the first electrode is a single layer.

45. The light emitting apparatus according to claim 40, wherein the second electrode is a single layer.

46. The light emitting apparatus according to claim 40, wherein the light emitting apparatus is selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation apparatus, a personal computer and a portable information terminal.

47. The light emitting apparatus according to claim 40, wherein the organic compound of the first layer and the organic compound of the second layer are the same.

48. The light emitting apparatus according to claim 40, wherein the upper end portion of the insulating substance has a first radius of curvature, and wherein the lower end portion of the insulating substance has a second radius of curvature.

49. The light emitting apparatus according to claim 40, wherein the upper end portion of the insulating substance has a first radius of curvature, wherein the lower end portion of the insulating substance has a second radius of curvature, and wherein the first radius of curvature and the second radius of curvature is in a range of 0.2.mu.m though 3.mu.m.

50. A light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, the pixel portion comprising a first luminescent element and a second luminescent element over a substrate, wherein the first luminescent element comprises a first electrode, a first layer comprising an organic compound over the first electrode, and a part of a second electrode over the first layer comprising the organic compound, wherein the second luminescent element comprises a fourth electrode, a second layer comprising an organic compound over the fourth electrode, and a part of the second electrode over the second layer comprising the organic compound, wherein an insulating substance is over an end portion of the first electrode and an end portion of the fourth electrode, wherein upper and lower end portions of a side face of the insulating substance are round, wherein a third electrode is between the first and second luminescent elements, and wherein the third electrode is in contact with the insulating substance.

51. The light emitting apparatus according to claim 50, wherein the second electrode comprises Mg and Ag.

52. The light emitting apparatus according to claim 50, wherein the third electrode is above the first electrode.

53. The light emitting apparatus according to claim 50, wherein the third electrode is not connected to the first electrode.

54. The light emitting apparatus according to claim 50, wherein the first electrode is a single layer.

55. The light emitting apparatus according to claim 50, wherein the second electrode is a single layer.

56. The light emitting apparatus according to claim 50, wherein the light emitting apparatus is selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation apparatus, a personal computer and a portable information terminal.

57. The light emitting apparatus according to claim 50, wherein the organic compound of the first layer and the organic compound of the second layer are the same.

58. The light emitting apparatus according to claim 50, wherein the upper end portion of the insulating substance has a first radius of curvature, and wherein the lower end portion of the insulating substance has a second radius of curvature.

59. The light emitting apparatus according to claim 50, wherein the upper end portion of the insulating substance has a first radius of curvature, wherein the lower end portion of the insulating substance has a second radius of curvature, and wherein the first radius of curvature and the second radius of curvature is in a range of 0.2.mu.m though 3.mu.m.

60. A light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, the pixel portion comprising a first luminescent element and a second luminescent element over a substrate, wherein the first luminescent element comprises a first electrode, a first layer comprising an organic compound over the first electrode, and a part of a second electrode over the layer comprising the organic compound, wherein the second luminescent element comprises a fourth electrode, a second layer comprising an organic compound over the fourth electrode, and a part of the second electrode over the second layer comprising the organic compound, wherein an insulating substance is over an end portion of the first electrode and an end portion of the fourth electrode, wherein upper and lower end portions of a side face of the insulating substance are round, wherein a third electrode is between the first and second luminescent elements, and wherein the insulating substance is in contact with a part of the first layer comprising the organic compound and a part of the second layer comprising the organic compound.

61. The light emitting apparatus according to claim 60, wherein the second electrode comprises Mg and Ag.

62. The light emitting apparatus according to claim 60, wherein the third electrode is above the first electrode.

63. The light emitting apparatus according to claim 60, wherein the third electrode is not connected to the first electrode.

64. The light emitting apparatus according to claim 60, wherein the first electrode is a single layer.

65. The light emitting apparatus according to claim 60, wherein the second electrode is a single layer.

66. The light emitting apparatus according to claim 60, wherein the light emitting apparatus is selected from the group consisting of a video camera, a digital camera, a goggle type display, a car navigation apparatus, a personal computer and a portable information terminal.

67. The light emitting apparatus according to claim 60, wherein the organic compound of the first layer and the organic compound of the second layer are the same.

68. The light emitting apparatus according to claim 60, wherein the upper end portion of the insulating substance has a first radius of curvature, and wherein the lower end portion of the insulating substance has a second radius of curvature.

69. The light emitting apparatus according to claim 60, wherein the upper end portion of the insulating substance has a first radius of curvature, wherein the lower end portion of the insulating substance has a second radius of curvature, and wherein the first radius of curvature and the second radius of curvature is in a range of 0.2.mu.m through 3.mu.m.

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Description

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BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a light emitting apparatus using a luminescent element emitting fluorescence or phosphorescence by applying an electric field to an element having a film including an organic compound (hereinafter, described as "organic compound layer") between a pair of electrodes and a method of fabricating the light emitting apparatus. Further, a light emitting apparatus in the specification includes an image display device, a light emitting device or a light source (including illuminating device). Further, a light emitting apparatus includes all of a module of a light emitting apparatus attached with a connector, for example, FPC (Flexible Printed Circuit) or TAB (Tape Automated Bonding) tape or TCP (Tape Carrier Package), a module provided with a printed circuit board at a front end of TAB tape or TCP and a module in which a luminescent element is directly mounted with IC (Integrated Circuit) by COG (Chip On Glass) system.

2. Description of the Related Art

There is expected application of a luminescent element using an organic compound characterized in thin shape, light weight, high response and direct current voltage drive as a light emitting body to a flat panel display of next generation. Particularly, a display apparatus arranged with luminescent elements in a matrix-like shape seems to be superior to a liquid crystal display apparatus of a related art in view of wide viewing angle and excellence in optical recognizing performance.

According to the light emitting mechanism of a luminescent element, it is said that by interposing an organic compound layer between a pair of electrodes and applying voltage, an electron injected from a cathode and a hole injected from an anode are recombined at a center of light emittance in the organic compound layer to form molecular exciton and when the molecular exciton returns to the ground state, energy is discharged to emit light. There are known singlet excitation and triplet excitation in an excited state and it seems that light can be emitted by way of either of the excited states.

It is possible to use driving methods of passive matrix drive (simple matrix type) and active matrix drive (active matrix type) for such a light emitting apparatus formed by arranging luminescent elements in a matrix-like shape. However, when a pixel density is increased, the active matrix type provided with a switch for each pixel (or dot) is advantageous since the active matrix type can be driven at low voltage.

Further, although a low molecular species material and a high molecular species (polymer species) material are respectively researched for an the organic compound for constituting the organic compound layer (strictly speaking, light emitting layer) regarded to be the core of a luminescent element, more attention is given to the high molecular species material facilitated to handle and having high heat resistance than the low molecular species material.

Further, although there are known methods such as vapor deposition method, spin coating method and ink jet method for a film forming method of the organic compounds, as a method for realizing full color formation by using the high molecular species material, spin coating method and ink jet method are particularly well known.

However, when the spin coating method is used, the organic compound is formed over an entire film forming surface and therefore, it is difficult to selectively form the film in which the organic compound is formed only at a portion intended to form the film and the film is not formed at a portion which is not necessary to form the film.

Further, the active matrix type light emitting apparatus is formed with a wiring for inputting an electric signal from an outside power source to a drive circuit formed over a substrate, and a wiring for electrically connecting a luminescent element comprising a cathode, an anode and the organic compound layer formed by the organic compound formed at a pixel portion and the outside power source and therefore, when the organic compound is formed at the portions of the wirings connected to the outside power source, there poses a problem that ohmic contact cannot be achieved with outside power source.

Meanwhile, according to the ink jet method known as a method of selectively forming an organic compound of a high molecular species, although organic compounds for emitting three kinds (R, G, B) of light can be coated to divide in one step, film forming accuracy is poor, the control is difficult and therefore, uniformity is not achieved and dispersion is liable to be brought about. As causes of the dispersion in the ink jet method, a dispersion in nozzle pitch, a dispersion in bending in ink flying, a dispersion in stage matching accuracy and a dispersion in timings of delivery of ink and movement of stage. For example, there are problems in conditions of execution in which a nozzle for ink jet is clogged by internal viscous resistance of ink prepared by dissolving the organic compound in a solvent and ink injected from the nozzle is not impacted to a desired position and a problem in practical use in which the need for an exclusive apparatus having a highly accurate stage, an automatic alignment mechanism and an ink head becomes costly. Further, ink spreads after impact and therefore, a margin to some degree is needed as an interval between contiguous pixels to thereby make highly fine formation difficult.

SUMMARY OF THE INVENTION

Hence, it is an object of the invention to provide a method of selectively forming a high molecular species material layer which is simpler than using an ink jet method in a light emitting apparatus of an active matrix type using a high molecular species organic compound. Further, it is an object thereof to simply form a structure in which the organic compound layer is not formed at a connection portion of a wiring connected to an outside power source by enabling to selectively form the high molecular species material layer.

Further, according to a light emitting apparatus, there poses a problem that outside scenery is imaged on an observing face (face directed to a side of an observer) by reflecting incident outside light (light outside of the light emitting apparatus) by a rear face of a cathode (face on a side in contact with a luminescent layer) at a pixel which does not emit light. Further, in order to avoid the problem, it is devised that a circularly polarized light film is pasted on an observing face of the light emitting apparatus to thereby prevent outside scenery from being imaged on the observing face, however, the circularly polarized light film is very expensive and therefore, there poses a problem of an increase in the fabrication cost.

According to the invention, a film comprising a high molecular species material is formed over an entire face of a lower electrode connected to a thin film transistor by a coating method and thereafter, a film comprising a polymer (high molecular material) is etched by etching by plasma to thereby enable to selectively form the high molecular species material layer.

According to constitution 1 of the invention related to a fabricating method disclosed in the specification, there is provided a method of fabricating a light emitting apparatus, the method comprising:

a forming a film comprising an organic compound over(above)a first electrode by a coating method;

selectively etching the film comprising the organic compound by etching plasma; and

selectively forming a second electrode over the film comprising the organic compound.

Further, the etching by plasma may be carried out after selectively forming the second electrode after forming the organic compound film by spin coating.

According to constitution 2 of the invention related to a fabricating method disclosed in the specification, there is provided a method of fabricating, the method comprising:

forming a film comprising a organic compound over a first electrode by a coating method;

selectively forming a second electrode over said film comprising said organic compound; and

selectively etching said film comprising said organic compound by plasma etching.

Further, a third electrode for constituting an auxiliary electrode may be formed for forming an upper electrode by low resistance and according to constitution 3 of the invention related to a fabricating method disclosed in the specification, the method comprising:

forming a thin film transistor over a first substrate;

forming a first electrode connected to the thin film transistor;

forming an insulating substance covering an end portion of the first electrode;

forming a third electrode comprising a metal material over the insulating substance;

forming a film comprising an organic compound over the first electrode by a coating method;

exposing the third electrode by selectively etching said film comprising said organic compound using a mask by plasma etching;

selectively forming a second electrode comprising a material having a light transmitting performance on said film comprising said organic compound;

forming a protective film; and

pasting together the first substrate and the second substrate.

Further, in the above-described constitution 3, the protective film is characterized to be an insulating film whose major component is silicon oxide, an insulating film whose major component is silicon nitride, a film whose major component is carbon or a laminated film of these. Further, in the above-described constitution 3, an interval between the first substrate and the second substrate is characterized to be a range of 2 .mu.m through 30 .mu.m.

Further, in the above-described respective constitutions, in vacuum heating said film comprising said organic compound, said film comprising said polymer, formed over the first electrode by a coating method after forming said layer comprising said organic compound, said comprising a polymer, over the first electrode.

Further, in the above-described respective constitutions, the first electrode is characterized to be an anode or a cathode of the luminescent element electrically connected to a TFT.

Further, in the above-described respective constitutions, the plasma is generated by exciting a single kind or a plurality of kinds of gases selected from the group constituting of Ar, H, F and O.

Further, in the above-described respective constitutions, the organic compound layer is characterized to be a material for emitting light of white color and combined with a color filter provided at the second substrate, or the organic compound layer is characterized to be a material for emitting light of a single color and combined with a color changing layer or a coloring layer provided at the second substrate.

Further, the invention devises a shape of an insulating substance (referred to as bank, partition wall, barrier, embarkment or the like) provided between respective pixels to eliminate a failure in coverage in forming a high molecular organic compound film by a coating method.

Further, according to constitution 4 of the invention disclosed in the specification, there is provided a light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, said pixel portion having a plurality of luminescent elements between a first substrate having an insulating surface and a second substrate having a light transmitting performance;

wherein each of said plurality of luminescent elements comprises a first electrode, a layer comprising an organic compound in contact with an upper face of the first electrode, and a second electrode in contact with an upper face of the layer comprising the organic compound: and

wherein an end portion of the first electrode is covered by an insulating substance, a side face of the insulating substance includes a curved face having a first radius of curvature and a curved face having a second radius of curvature and the layer comprising the organic compound, said layer comprising a polymer, is provided over the insulating substance and the first electrode.

Further, as constitution 5 of the invention, when a third electrode for constituting an auxiliary electrode for forming an upper electrode by low resistance is formed, there is provided a light emitting apparatus which is a light emitting apparatus comprising a drive circuit, a terminal portion and a pixel portion, said pixel portion having a plurality of luminescent elements between a first substrate having an insulating surface and a second substrate having a light transmitting performance;

wherein each of said plurality of luminescent elements comprises a first electrode, a layer comprising an organic compound over the first electrode, and a second electrode over the layer comprising the organic compound: and

wherein an end portion of the first electrode is covered by an insulating substance, a side face of the insulating substance includes a curved face having a first radius of curvature and a curved face having a second radius of curvature, a third electrode is provided over the insulating substance and the layer comprising the organic compound, the layer comprising a polymer, is provided over the insulating substance and the first electrode.

Further, in the above-described constitutions 4, 5, the organic compound layer is a laminated layer of a layer comprising a polymer and a layer comprising a low molecular material.

Further, in the above-described constitutions 4, 5, the layer comprising the organic compound comprises a material which is characterized to be luminescent in white color and combined with a color filter provided at the second substrate, or the layer comprising the organic compound is characterized to comprise a material of emitting light of a single color and combined with a color changing layer or a coloring layer provided at the second substrate.

Further, in the above-described constitutions 4, 5, an upper end portion of the insulating substance is characterized to the curved face having the first radius of curvature, a lower end portion of the insulating substance includes the curved face having the second radius of curvature and the first radius of curvature and the second radius of curvature is a range of 0.2 .mu.m through 3 .mu.m. Further, a taper angle of the insulating substance may be a range of 35.degree. through 55.degree..

Further, in the above-described constitutions 4, 5, the second substrate characterized to include a recessed portion provided with a drying agent and the recessed portion overlaps a part of an entire drive circuit provided over the first substrate.

Further, in the above-described constitutions 4, 5, an interval between the first substrate and the second substrate is characterized to be a range of 2 .mu.m through 30 .mu.m.

Further, in the above-described constitutions 4, 5, wherein said layer comprising said organic compound comprises poly(ethylenedioxythiophene)/poly(stylenesulfonic acid).

Further, an EL element includes a layer including an organic compound achieving luminescence (Electro Luminescence) generated by applying an electric field, an anode, and a cathode. The luminescence in the organic compound includes luminescence (fluorescence) in returning from a singlet excited state to the ground state and luminescence (fluorescence) in returning from a triplet excited state to the ground state. And a light emitting apparatus fabricated by a fabricating apparatus and a film forming method of the invention is applicable to both cases of using luminescence.

A luminescent element (EL element) having an EL layer is constituted by a structure in which the EL layer is interposed between a pair of electrodes and the EL layer is normally constructed by a laminated structure. Representatively, there is pointed out a laminated structure of "hole transporting layer/luminescent layer/electron transporting layer" proposed by Tang et al. of Kodak Eastman Company. The structure is provided with a very high luminescence efficiency and currently, almost all the light emitting apparatus on which research and development is progressed adopt the structure.

Further, otherwise, there may be constructed a structure of laminating a hole injecting layer, a hole transporting layer, a luminescent layer, an electron transporting layer or a hole injecting layer, a hole transporting layer, a luminescent layer, an electron transporting layer, an electron injecting layer, in this order on an anode. The luminescent layer may be doped with a fluorescent pigment or the like. Further, all of the layers may be formed by using a low molecular species material or using a high molecular species material. Further, in the specification, all the layers provided between a cathode and an anode are generally referred to as EL layers. Therefore, all of the hole injecting layer, the hole transporting layer, the luminescence layer, the electron transporting layer and the electron injecting layer are included in the EL layers.

Further, according to an active matrix type light emitting apparatus, there are conceivable two ways of structures by a direction of emitting light. One is a structure in which light emitted from an EL element transmits through an opposed substrate to emit to enter eyes of the observer. In this case, the observer can recognize an image from a side of the opposed substrate. Other is a structure in which light emitted from an EL element transmits through an element substrate to emit to enter eyes of the observer. In this case, the observer can recognize the image from the side of the element substrate. The invention is applicable to both of two ways of structures.

Further, in the light emitting apparatus of the invention, a method of driving to display a screen is not particularly limited, for example, a dot successive driving method, a line successive driving method or a face successive driving method may be used. Representatively, as the line successive driving method, a time division gray scale driving method or an area gray scale driving method may pertinently be used. Further, an image signal inputted to a source line of the light emitting apparatus may be an analog signal, may be a digital signal and a drive circuit or the like may pertinently be designed in accordance with an image signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are views showing sectional views (Embodiment 1);

FIGS. 2A, 2B and 2C are views showing an etching step (Embodiment 2);

FIGS. 3A, 3B and 3C are a top view and sectional views showing an arrangement of a drying agent (Embodiment 3);

FIGS. 4A, 4B and 4C are views showing element structures (Embodiment 4);

FIGS. 5A, 5B and 5C are schematic views when full color formation is achieved by using emittance of white color (Embodiment 4);

FIGS. 6A, 6B, 6C and 6D are schematic views when full color formation is achieved by laminating a high molecular material and a low molecular material (Embodiment 5);

FIG. 7 is a view showing a fabricating apparatus (Example 1);

FIG. 8 is a view showing a top view of a pixel (Embodiment 1);

FIGS. 9A and 9B are views showing a top view and a sectional view of a pixel (Example 1);

FIGS. 10A, 10B and 10C are views showing step diagrams (Embodiment 2);

FIGS. 11A and 11B are a top view and a sectional view of an active type display apparatus (Embodiment 2);

FIGS. 12A, 12B, 12C, 12D, 12E and 12F are views showing examples of electronic apparatus;

FIGS. 13A, 13B and 13C are views showing examples of electronic apparatus;

FIG. 14 is a diagram showing transmittance of a coloring layer (Embodiment 4);

FIG. 15 is a diagram showing coordinates of chromaticity (Embodiment 4);

FIG. 16 is a photographic view showing a section (Embodiment 1); and

FIG. 17 is a photographic view showing a section (Comparative Example).

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments of the invention will be explained as follows.

(Embodiment 1)

FIG. 1A shows a sectional view of an active matrix type light emitting apparatus. Here, a luminescent element 13 having a laminated structure comprising a high molecular material for emitting light of white color will be explained as an example.

In FIG. 1A, a plurality of TFTs 1 through 3 are provided over a substrate having an insulating surface. Further, TFT 1 and TFT 2 are elements constituting portions of a drive circuit portion. Further, TFT3 provided at a pixel portion is an element for controlling current flowing in EL layers 11a and 11b for emitting light of white color and numeral 4 designates a source electrode or a drain electrode. Here, TFT 3 constitutes TFT having a plurality of channels. Further, a channel length L of TFT 3 is preferably equal to or larger than 100 .mu.m. When the channel length L is prolonged, oxide film capacitance C.sub.OX is increased and therefore, a portion of the capacitance can be utilized as hold capacitance of an organic luminescent element. According to a related art, hold capacitance is formed for each pixel and therefore, a space for forming the hold capacitance is needed and a capacitance line or a capacitance electrode is provided, however, the capacitance line or the capacitance electrode can be omitted by constituting the pixel of the invention. Further, when the hold capacitance is formed by the oxide capacitance C.sub.ox, the hold capacitance is formed by a gate electrode and a semiconductor (channel forming region) overlapping the gate electrode by constituting a dielectric body by the gate insulating film. Therefore, even when the channel length of TFT is prolonged, in a case in which as shown by FIG. 8, a semiconductor layer of driving TFT 507 connected to a pixel electrode 508 is arranged below a current supply line 504 and a source signal line 501 arranged at an upper layer of a gate electrode, the pixel can be designed without reducing numerical aperture. That is, by constituting the pixel as shown by FIG. 8, even when a space for forming a capacitance electrode and a capacitance wiring is omitted, sufficient hold capacitance can be provided and the numerical aperture can be increased. Further, in case of prolonging the channel length L, even when a dispersion in a TFT fabricating process such as a condition of irradiating a laser beam is brought about, a dispersion in an electric property among respective TFTs can be reduced. Further, numeral 5 designates an interlayer insulating film comprising an organic insulating material and numeral 6 designates an interlayer insulating material comprising an inorganic insulating film material.

Further, numeral 7 designates a first electrode, that is, an anode (or cathode) of an organic luminescent element and numeral 12 designates a second electrode, that is, a cathode (or anode) of the organic luminescent element. Here, as designated by numeral 20, the cathode is constituted by a laminated film of a thin metal layer (representatively, alloy of MgAg, MgIn, AlLi) and a transparent conductive film (ITO (indium oxide tin oxide alloy), indium oxide zinc oxide alloy (In.sub.2O.sub.3--ZnO), zinc oxide (ZnO)) for transmitting light from each luminescent element. Further, the thin metal film functions as the cathode and the transparent conductive film functions as a wiring for reducing electric resistance of the cathode.

Further, both end portions of the first electrode 7 and an interval therebetween are covered by an organic insulating substance 8 (also referred to as barrier or bank). Further, the organic insulating substance 8 may be covered by an inorganic insulating film.

According to the invention, a sectional shape of the organic insulating substance 8 becomes important. FIG. 1B shows an enlarged view of a periphery of the organic insulating substance 8. In a case of forming an organic compound film on the organic insulating substance 8 by a coating method or in a case of forming a metal film for constituting a cathode by vapor deposition method, when a curved face is not provided at a lower end or an upper end of the organic insulating substance, as shown by FIG. 17, a failure in film forming of forming a projected portion is brought about at the upper end portion of the organic substance. Hence, the invention is characterized in constituting a shape having a curved face having a first radius of curvature at the upper end portion of the organic insulating substance 8 and having a curved face having a second radius of curvature at the lower end portion of the organic insulating substance 8 as shown by FIG. 16. Further, both of the first radius of curvature and the second radius of curvature are preferably 0.2 .mu.m through 3 .mu.m. By the invention, coverage of the organic compound film or the metal fil