Light emitting device and a method of manufacturing the same

• US 6,420,834 B2
• Filed: 03/27/2001
• Issued: 07/16/2002
• Est. Priority Date: 03/27/2000
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Fukunaga, Takeshi, Hiroki, Masaaki, Yamazaki, Shunpei
• Primary Examiner(s): Philogene, Haissa
• Application Number:
  US09/817,674
• Publication Number:
  US 20010026125A1
• Time in Patent Office: 476 Days
• Field of Search: 315/169.3, 315/169.1, 315/167, 313/257, 313/261, 313/268, 313/498, 313/505, 313/506, 313/238, 345/55, 345/76, 345/92, 349/42, 349/69, 427/66, 257/448
• US Class Current: 315/169.3
• CPC Class Codes: G09G 3/3208 organic, e.g. using organic light-emitting diodes [OLED]
• 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 27/127 with a particular formation, treatment or patterning of the active layer specially adapted to the circuit arrangement
• 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: H10K 59/122 Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/131 Interconnections, e.g. wiring lines or terminals
• CPC Class Codes: H10K 71/00 Manufacture or treatment specially adapted for the organic devices covered by this subclass
• CPC Class Codes: H10K 71/10 Deposition of organic active material
• CPC Class Codes: H10K 71/166 using selective deposition, e.g. using a mask
• CPC Class Codes: H10K 71/40 Thermal treatment, e.g. annealing in the presence of a solvent vapour

Abstract

To provide a light emitting device having a highly definite pixel portion. An anode (102) and a bank (104) orthogonal to the anode (102) are formed on an insulator (101). A portion of the bank (104) (controlling bank 104b) is made of a metal film. By applying a voltage thereto, an electric field is formed, and a track of an EL material that is charged with an electric charge can be controlled. Thus, it becomes possible to control a film deposition position of an EL layer with precision by utilizing the above method.

Claims

1. A light emitting device comprising:

at least one thin film transistor on an insulating surface;

an anode electrically connected to said thin film transistor;

a cathode provided opposite said anode; and

a luminous material provided between said anode and said cathode,

wherein said anode is surrounded by a bank, and a portion of said bank contains a metal film.

2. A light emitting device according to claim 1, wherein said luminous material is an EL material.

3. A light emitting device according to claim 1, wherein said metal film has a tapered shape.

4. A light emitting device according to claim 1, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

5. A light emitting device comprising:

at least one thin film transistor on an insulating surface;

an anode electrically connected to said thin film transistor;

a cathode provided opposite said anode; and

a luminous material provided between said anode and said cathode,

wherein said anode is surrounded by a bank, and said bank is formed of a lamination of an insulating film and a metal film.

6. A light emitting device according to claim 5, wherein said luminous material is an EL material.

7. A light emitting device according to claim 5, wherein said metal film has a tapered shape.

8. A light emitting device according to claim 5, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

9. A light emitting device comprising:

at least one thin film transistor on an insulating surface;

a cathode electrically connected to said thin film transistor;

an anode provided opposite said cathode; and

a luminous material provided between said cathode and said anode,

wherein said cathode is surrounded by a bank and a portion of said bank contains a metal film.

10. A light emitting device according to claim 9, wherein said luminous material is an EL material.

11. A light emitting device according to claim 9, wherein said metal film has a tapered shape.

12. A light emitting device according to claim 9, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

13. A light emitting device comprising:

at least one thin film transistor on an insulating surface;

a cathode electrically connected to said thin film transistor;

an anode provided opposite said cathode; and

a luminous material provided between said cathode and said anode,

wherein said cathode is surrounded by a bank, and said bank is formed of a lamination of an insulating film and a metal film.

14. A light emitting device according to claim 13, wherein said luminous material is an EL material.

15. A light emitting device according to claim 13, wherein said metal film has a tapered shape.

16. A light emitting device according to claim 13, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

17. A method of manufacturing a light emitting device, comprising the steps of:

forming at least one thin film transistor on an insulating surface;

forming a pixel electrode electrically connected to said thin film transistor;

forming a bank so as to surround said pixel electrode; and

forming an EL material over said pixel electrode while charging a portion of said bank with a negative or positive charge.

18. A method of manufacturing a light emitting device according to claim 17, wherein said step of forming said EL material is performed by an evaporation method, an ion plating method, or an ink jet method.

19. A method of manufacturing a light emitting device according to claim 17, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

20. A method of manufacturing a light emitting device, comprising the steps of:

forming at least one thin film transistor on an insulating surface;

forming a pixel electrode electrically connected to said thin film transistor;

forming a bank so as to surround said pixel electrode; and

while charging a portion of said bank with a negative or positive charge, forming an EL material charged to have a same polarity as said bank over said pixel electrode.

21. A method of manufacturing a light emitting device according to claim 20, wherein said step of forming said EL material is performed by an evaporation method, an ion plating method, or an ink jet method.

22. A method of manufacturing a light emitting device according to claim 20, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

23. A method of manufacturing a light emitting device, comprising the steps of:

forming at least one thin film transistor on an insulating surface;

forming a pixel electrode electrically connected to said thin film transistor;

forming a bank composed of a lamination of an insulating film and a metal film so as to surround said pixel electrode; and

forming an EL material over said pixel electrode while charging said metal film with a negative or positive charge.

24. A method of manufacturing a light emitting device according to claim 23, wherein said step of forming said EL material is performed by an evaporation method, an ion plating method, or an ink jet method.

25. A method of manufacturing a light emitting device according to claim 23, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.

26. A method of manufacturing a light emitting device, comprising the steps of:

forming at least one thin film transistor on an insulating surface;

forming a pixel electrode electrically connected to said thin film transistor;

forming a bank composed of a lamination of an insulating film and a metal film so as to surround said pixel electrode; and

while charging said metal film with a negative or positive charge, forming an EL material charged to have a same polarity as said metal film over said pixel electrode.

27. A method of manufacturing a light emitting device according to claim 26, wherein said step of forming said EL material is performed by an evaporation method, an ion plating method, or an ink jet method.

28. A method of manufacturing a light emitting device according to claim 26, wherein said light emitting device is one selected from the group consisting of a video camera, a digital camera, a goggle type display, car navigation system, a note book type computer, and a mobile telephone.