JPS6143838B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a light emitting device.

A conventional example is shown in FIG. That is, this light emitting device has a transparent electrode 2 layered on a glass substrate 1, a dielectric film 3 layered on the transparent electrode 2, and a fluorescent film 4,
A dielectric film 5 and a metal electrode 6 are laminated.
An AC power source 7 is connected between the electrodes 2 and 6. In this light emitting device, the dielectric films 3 and 5 are made of a material with a high dielectric constant ( _{Y2O 3} , BaTiO _3, etc.) to improve the life of the device. However, the drawback was that the higher the insulation, the higher the driving voltage. In order to compensate for this drawback, the dielectric constants of the dielectric films 3 and 5 are increased and the layers are made thinner (about 2000 Å) to lower the voltage applied to the dielectric films 3 and 5 as much as possible, but this is not sufficient.

Therefore, an object of the present invention is to provide a method for manufacturing a light emitting device that can prevent insulation deterioration due to pinholes and can realize low voltage driving.

A first embodiment of this invention will be explained with reference to FIG. That is, in this method of manufacturing a light emitting device, the glass substrate 1a is heated to about 400°C.
Using a sintering target of indium oxide containing tin oxide on top, that is, 10 mol% SnO ₂ + In ₂ O ₃ (indium oxide (ITO), Sn: 10 mol%), inert gas argon (Ar) was used.
Gas pressure 3× containing 5% or less oxygen (O ₂ )
Stratified in an atmosphere of 10 ^-2 Torr. The methods include sputtering deposition, activated sputtering, activated deposition,
Perform with ion blasting, etc. On the transparent conductive layer 2a thus formed, the same material as above is laminated by the same method as above in an argon gas atmosphere containing 10% or more of oxygen gas to form an insulating layer 3a. This allows only the electrode portion to be covered from the outside without breaking the vacuum state during the formation of the transparent conductive layer 2a, and only the mixing ratio of the atmospheric gases to be changed by operating the valve. In this way, as is well known, the insulating layer 3a has a very high resistance. in addition
Electroluminescent layer 4 doped with impurities such as ZnS and ZnSe
a, and further an aluminum metal electrode layer 6a is formed thereon. As a result, it was confirmed that it was possible to prevent insulation deterioration due to pinholes, and that low voltage driving was possible due to the reduction in layer thickness. However, at present, if such a method is used, why is the insulating layer 3a
Although it is unclear whether the withstand voltage of the transparent conductive layer 2a is improved, if the pinhole generation mechanism is caused by some abnormality in the underlying layer, the pinholes in the transparent conductive layer 2a and the pinholes in the insulating layer 3a are in the same position. It is thought that this is the case.

A second embodiment of the invention will be explained with reference to FIG. That is, in the structure of the first embodiment, the aluminum metal electrode layer 6a is activated (reactive) between the electric field generating layers 4a by the same operation as in the first embodiment.
An insulating layer 8 of an electrode metal oxide, that is, alumina (AI ₂ O ₃ ), is provided by sputtering, vapor deposition, ion plating, or the like. In this case, high brightness can be obtained although the driving voltage becomes somewhat high. Note that even if this example is applied to a conventional structure,
Y ₂ O ₃ and BaTiO ₃ can be made thinner, making it possible to lower the voltage.

As described above, in the method for manufacturing a light emitting device of the present invention, a transparent electrode layer is formed using indium oxide containing tin oxide, and an insulating layer is formed by layering the same material in an atmosphere with a higher oxygen concentration than the former. form,
Furthermore, since the electroluminescent layer and the metal electrode layer are laminated, it is possible to drive at a low voltage, prevent dielectric breakdown of the electroluminescent layer, and improve the lifespan.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional device, FIG. 2 is a cross-sectional view of a device according to a first embodiment of the present invention, and FIG. 3 is a cross-sectional view of a device according to a second embodiment. 1a...Glass substrate, 2a...Transparent conductive layer, 3
a... Insulating layer, 4a... Electroluminescent layer, 6a... Metal electrode layer, 8... Oxide insulating layer.

Claims (1)

[Claims] 1. A transparent conductive layer forming step of depositing indium oxide containing tin oxide on a glass substrate heated to a predetermined temperature in an inert gas atmosphere at a predetermined pressure, and adding oxygen to the inert gas. an insulating layer forming step of forming a layer of the same material on the transparent conductive layer in an atmosphere containing about 10% or more gas; and a step of forming an electroluminescent layer on the insulating layer formed by this step; and forming a metal electrode layer on the electroluminescent layer. 2. The method of manufacturing a light emitting device according to claim 1, wherein an oxide insulating layer is formed on the electroluminescent layer side of the metal electrode layer.