Light-emitting device including substrate having cavity, and method for fabricating the light-emitting device

• US 9,659,524 B2
• Filed: 12/16/2014
• Issued: 05/23/2017
• Est. Priority Date: 06/21/1999
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Fukunaga, Takeshi, Yamauchi, Yukio
• Primary Examiner(s): Williams, Joseph L
• Application Number:
  US14/571,897
• Publication Number:
  US 20150138174A1
• Time in Patent Office: 889 Days
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2300/04 Structural and physical details of display devices
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2300/0417 Special arrangements specific to the use of low carrier mobility technology
• CPC Class Codes: G09G 2300/0426 Layout of electrodes and connections
• CPC Class Codes: G09G 2300/0842 forming a memory circuit, e.g. a dynamic memory with one capacitor
• CPC Class Codes: G09G 3/2018 by time modulation using two or more time intervals
• CPC Class Codes: G09G 3/2022 using sub-frames
• CPC Class Codes: G09G 3/30 using electroluminescent panels
• CPC Class Codes: G09G 3/32 semiconductive, e.g. using light-emitting diodes [LED]
• CPC Class Codes: G09G 3/3225 using an active matrix
• CPC Class Codes: G09G 3/3258 with pixel circuitry controlling the voltage across the light-emitting element
• CPC Class Codes: H01L 27/1277 using a crystallisation promoting species, e.g. local introduction of Ni catalyst
• CPC Class Codes: H01L 27/1296 adapted to increase the uniformity of device parameters
• CPC Class Codes: H01L 27/156 two-dimensional arrays
• CPC Class Codes: H01L 29/045 by their particular orientation of crystalline planes
• CPC Class Codes: H01L 29/0603 characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions isolation regions between components H01L21/76; design considerations for integrated circuits H01L27/00; geometrical design considerations for devices H01L29/0657
• CPC Class Codes: H01L 29/786 Thin film transistors, i.e. transistors with a channel being at least partly a thin film transistors having only the source or the drain region on an insulator layer H01L29/0653; thin film FinFETs H01L29/785
• 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 29/78624 the source and the drain regions being asymmetrical
• 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 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: H01L 33/62 : Arrangements for conducting electric current to or from the semiconductor body, e.g. lead-frames, wire-bonds or solder balls
• CPC Class Codes: H10K 2102/3026 : Top emission
• CPC Class Codes: H10K 50/87 : Arrangements for heating or cooling
• CPC Class Codes: H10K 59/12 : Active-matrix OLED [AMOLED] displays
• CPC Class Codes: H10K 59/1213 : the pixel elements being TFTs
• CPC Class Codes: H10K 59/122 : Pixel-defining structures or layers, e.g. banks
• CPC Class Codes: H10K 59/8794 : Arrangements for heating and cooling

Abstract

An EL display device capable of performing clear multi-gradation color display and electronic equipment provided with the EL display device are provided, wherein gradation display is performed according to a time-division driving method in which the luminescence and non-luminescence of an EL element (109) disposed in a pixel (104) are controlled by time, and the influence by the characteristic variability of a current controlling TFT (108) is prevented. When this method is used, a data signal side driving circuit (102) and a gate signal side driving circuit (103) are formed with TFTs that use a silicon film having a peculiar crystal structure and exhibit an extremely high operation speed.

Claims

1. A light-emitting device comprising:

a first substrate;

a second substrate over the first substrate, the second substrate being smaller than the first substrate so that the first substrate has a region which does not overlap with the second substrate; and

a light-emitting portion between the first substrate and the second substrate,

wherein;

the second substrate has a cavity;

the first substrate and the second substrate are bonded to each other so that the cavity is interposed between the first substrate and the second substrate;

the light-emitting portion is located in the cavity; and

the light-emitting portion comprises a light-emitting element.

2. The light-emitting device according to claim 1,

wherein the light-emitting element comprises:

a first electrode;

an insulating film over the first electrode, the insulating film having an opening which overlaps with the first electrode;

an electroluminescent layer over and in contact with the first electrode and the insulating film; and

a second electrode overlapping with the electroluminescent layer and the insulating film.

3. The light-emitting device according to claim 2,

wherein the insulating film has a tapered shape in a region which overlaps with the first electrode.

4. The light-emitting device according to claim 2,

wherein the insulating film has a tapered shape in a region which overlaps with an end portion of the first electrode.

5. The light-emitting device according to claim 1, further comprising a wiring,

wherein the wiring extends to the region from the cavity and is exposed in the region.

6. The light-emitting device according to claim 2, further comprising a second insulating film over and in contact with the second electrode.

7. The light-emitting device according to claim 1, further comprising a drying agent in the cavity.

8. The light-emitting device according to claim 2, wherein the first electrode comprises a transparent conductive film.

9. A light-emitting device comprising:

a first substrate;

a second substrate over the first substrate, the second substrate being smaller than the first substrate so that the first substrate has a region which does not overlap with the second substrate; and

a light-emitting portion between the first substrate and the second substrate,

wherein;

the second substrate has a cavity and a rim which surrounds the cavity;

the first substrate and the rim are bonded to each other with an adhesive so that the cavity is interposed between the first substrate and the second substrate;

the light-emitting portion is located in the cavity;

the light-emitting portion comprises a light-emitting element; and

the rim has a surface which is in contact with the adhesive and parallel to a top surface of the first substrate.

10. The light-emitting device according to claim 9,

wherein the light-emitting element comprises:

a first electrode;

an insulating film over the first electrode, the insulating film having an opening which overlaps with the first electrode;

an electroluminescent layer over and in contact with the first electrode and the insulating film; and

a second electrode overlapping with the electroluminescent layer and the insulating film.

11. The light-emitting device according to claim 10,

wherein the insulating film has a tapered shape in a region which overlaps with the first electrode.

12. The light-emitting device according to claim 10,

wherein the insulating film has a tapered shape in a region which overlaps with an end portion of the first electrode.

13. The light-emitting device according to claim 9, further comprising a wiring,

wherein the wiring extends to the region from the cavity and is exposed in the region.

14. The light-emitting device according to claim 10, further comprising a second insulating film over and in contact with the second electrode.

15. The light-emitting device according to claim 9, further comprising a drying agent in the cavity.

16. The light-emitting device according to claim 10, wherein the first electrode comprises a transparent conductive film.

17. A method for fabricating a light-emitting device, the method comprising:

forming a light-emitting portion over a first substrate, the light-emitting portion including a light-emitting element; and

bonding a second substrate having a cavity to the first substrate so that the light-emitting portion is sealed with a drying agent in the cavity between the first substrate and the second substrate,

wherein the second substrate is smaller than the first substrate so that the bonding provides a region to the first substrate, and

wherein the region is not covered by the second substrate.

18. The method according to claim 17,

wherein the light-emitting element is formed by:

forming a first electrode;

forming an insulating film having an opening over the first electrode so that the first electrode is exposed in the opening;

forming an electroluminescent layer over and in contact with the first electrode and the insulating film; and

forming a second electrode over the electroluminescent layer and the insulating film.

19. The method according to claim 18,

wherein the insulating film is formed so as to have a tapered shape in a region which overlaps with the first electrode.

20. The method according to claim 18,

wherein the insulating film is formed so as to have a tapered shape in a region which overlaps with an end portion of the first electrode.