JPH03141583A - Manufacture of electroluminescent element - Google Patents

Abstract

PURPOSE:To better the step coverage of an insulative layer so as to enhance the withstand voltage of the insulative layer by flattening a conductive film which applies an electric field to a light-emitting layer, and sequentially laminating the insulative layer and the light-emitting layer on the conductive film flattened. CONSTITUTION:A glass base 1 having a transparent conductive film 2 formed on the surface thereof is disposed inside a vacuum chamber 20 and an ion source 21 is disposed opposite to the glass base 1. Inactive gas ions of e.g. Ne, Ar, Kr and Xe are emitted by the ion source 21 and the glass base 1 is irradiated therewith. The irradiation of the inactive gas ions causes sputtering of the transparent conductive film 2 and flattening of the transparent conductive film 2 is achieved by the sputtering effect produced by the irradiation ions. Because a first insulative layer 3 is formed on the transparent conductive film 2 thus flattened, the step coverage of the first insulative layer 3 is bettered remarkably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing an electroluminescent device.

[Conventional technology]

The basic structure of a conventionally used electroluminescent element (hereinafter referred to as "rEL element") is shown in FIG. I TO (I
A transparent conductive film 2 such as ndiua+-Tin-Oxide) film is formed, and a 5ift film or S
A first insulator N3 is formed using an i3Ng film or the like. Then, a light-emitting layer 4 made of ZnS or the like and a second anti-green layer 5 are laminated in this order on the first anti-green layer 3.
1st. The light emitting layer 4 is sandwiched between the second anti-green layers 3 and 5. A back electrode 6 made of A2 or the like is formed on the second anti-green layer 5, and a high frequency power source 7 is connected between the back electrode 6 and the transparent conductive film 2.

When a high-frequency voltage from a high-frequency power source 7 is applied between the transparent conductive film 2 and the back electrode 6, carriers and the like trapped between the light-emitting layer 4 and the ever-green layer 3.5 are transferred to the light-emitting center of the light-emitting layer 4. collides with and excites this luminescent center. Then, when this luminescent center transitions to the ground state, light is emitted, and this light is transmitted through the glass substrate 1 and observed.

[Problem to be solved by the invention]

The transparent conductive film 2 made of an ITO film is formed by, for example, an electron beam heating evaporation method, and the transparent conductive film 2 deposited on the surface of the glass substrate l is grown in a columnar shape as shown in FIG. 6 (1). However, grain boundaries also exist. When the first ever-greening layer 3 is formed on the uneven transparent conductive film 2 by applying, for example, an electron beam heating evaporation method or a spacing method, the first never-greening layer 3 is formed as shown in FIG. As shown in 2), step coverage becomes poor. On the other hand, in order to efficiently transmit a high electric field to the light emitting layer 4, it is necessary to first
It is necessary to make the layer thickness as thin as possible, but as mentioned above, due to the poor step coverage, the layer thickness must be made thin (as indicated by the reference symbol ρl in Fig. 6 (2)). There will be areas where the insulating film does not adhere, making it impossible to function as a never-green layer.In other words,
The first green-proofing layer 3 has a low breakdown voltage because the underlying transparent conductive film 2 is uneven, making it difficult to thin the first layer 3. As a result, a high electric field is applied to the light emitting layer 4. The problem was that the transmission efficiency was poor.

A similar problem also occurs when the surface of the glass substrate l is uneven as shown in FIG. Therefore, the unevenness of the surface of the glass substrate 1 impedes improvement in the breakdown voltage of the first green-proofing layer 3.

An object of the present invention is to provide a method for manufacturing an electroluminescent device that solves the above-mentioned technical problems and allows good transmission of an electric field to a light emitting layer.

[Means to solve the problem]

The method for manufacturing an electroluminescent device of the present invention is characterized by flattening a conductive film that applies an electric field to a light-emitting layer, and sequentially laminating a never-green layer and a light-emitting layer on the flattened conductive film.

[Effect]

According to the configuration of the present invention, since the conductive film is flattened, the green-free layer formed on the flattened conductive film can have good step coverage and therefore have good breakdown voltage. Therefore, even if the layer thickness is reduced, it can sufficiently function as a never-green layer.

〔Example〕

An embodiment of the present invention will be described with reference to FIGS. 1 and 2 and the above-mentioned FIG. 5.

FIG. 1 is a cross-sectional view showing, in order of steps, a method for manufacturing an electroluminescent device (hereinafter referred to as an "rEL device") according to an embodiment of the present invention. In this embodiment, a transparent conductive film 2 made of an ITO film is formed on a glass substrate 1 by an electron beam heating vapor deposition method or the like as shown in FIG. Then, the uneven transparent conductive film 2 is subjected to a planarization process.

In this flattening process, the configuration shown in FIG. 2 is applied. That is, a transparent conductive film 2 (
Illustration is omitted in FIG. 2. ) is formed on the surface thereof, and an ion source 21 is arranged opposite to this glass substrate 1. For example, Ne is supplied from this ion source 21.

Inert gas ions such as Ar, Kr, and Xe are irradiated toward the glass substrate l. The transparent conductive film 2 is sputtered by this irradiation with inert gas ions, and the transparent conductive film 2 is planarized by the sputtering action of the irradiated ions.

A state in which the transparent conductive film 2 is flattened is shown in FIG. 1 (2), and from this state, as shown in FIG. It is formed by applying a sputtering method or the like. For example, if an evaporation source (not shown) for evaporating the material of the first green-proofing layer 3 is provided in the vacuum chamber 20 shown in FIG. The formation of the green layer 3 can be performed continuously.

As described above, in this embodiment, since the first green-proof layer 3 is formed on the flattened transparent conductive film 2, the first green-proof layer 3 is formed in steps as shown in FIG. 1(3). The coverage becomes extremely good. Therefore, even if the layer thickness is made thinner, there will be no areas where the insulating film is not adhered, as in the case of the conventional method, and therefore it can have sufficient withstand voltage. The layer thickness of N3 can be made thinner, and by making the first insulating layer N3 thinner, a high electric field from the transparent conductive film 2 can be transmitted to the light emitting layer 4 with high efficiency.

FIG. 3 is a conceptual diagram showing a configuration applied to the flat chlorination treatment in another embodiment of the present invention.

In this embodiment, vacuum annealing is performed during the planarization process. In other words, the base 3 disposed inside the vacuum chamber 30
A glass substrate 1 on which a transparent conductive film 2 (not shown in FIG. 3) is formed is placed, and a lamp heater 32 is disposed opposite to the glass substrate 1. The base 31 is equipped with a heater 33.
3 and a lamp heater 32 to heat the transparent conductive film 2 together with the glass base Fi,1. When the temperature of the transparent conductive film 2 rises to a predetermined value by heating, this transparent conductive film 2
Heat dissipation by radiation from the surface of the transparent conductive film 2 starts, but at this time, the transparent conductive film 2 is deformed into a shape with better heat dissipation efficiency. As a result, the transparent conductive film 2 is deformed from a columnar growth state to a flat shape, and in this way, the transparent conductive film 2 is flattened.

FIG. 4 is a cross-sectional view when the surface of the glass substrate 10 has irregularities. FIG. 4 (1) The transparent conductive film 2 is removed from the state shown in the figure in the fourth embodiment using the structure shown in FIG.
If the first insulating layer 3 is flattened as shown in FIG. 2 and the first insulating layer 3 is formed from this state, the first insulating layer N3 has good step coverage. In this way, even when the glass substrate 1 has irregularities, the step coverage of the first green constant layer 3 can be improved, and the first green constant layer 3 having a high breakdown voltage can be formed.

In the above-mentioned embodiment, the transparent conductive film 2 made of ITO was used as an example of the conductive film, but the present invention can be widely applied to any conductive film in which the formed film has an uneven shape. . Furthermore, when the surface of the glass substrate 1 is uneven as in the case of FIG. 4 and a conductive film with a layer thickness of 1100 nm or less is formed on the surface of the glass substrate 1, Since the surface has an uneven shape that reflects the surface condition of the glass substrate l, by applying the method of the present invention to any type of conductive film, the withstand voltage of the first ever-green layer 3 above it can be improved. be able to.

Furthermore, in the above-mentioned embodiment, the case where the transparent conductive film 2 is formed on the surface of the glass substrate 1 was taken as an example, but the present invention can easily be applied when any other arbitrary substrate other than the glass substrate 1 is used. It can be applied to

〔Effect of the invention〕

As described above, according to the method for manufacturing an electroluminescent device of the present invention, the step coverage of the never-green layer is improved, and therefore the withstand voltage of the never-green layer is improved.

This makes it possible to reduce the thickness of the never-green layer and transmit the electric field from the conductive film to the light-emitting layer with high efficiency, and as a result, it can also contribute to improving the light-emitting efficiency.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing a method for manufacturing an electroluminescent device according to an embodiment of the present invention in the order of steps, FIG. 2 is a conceptual diagram showing a configuration for flattening a transparent conductive film 2, and FIG. 4 is a cross-sectional view showing the situation when the surface of the glass substrate 1 is uneven, and FIG. 5 is a basic diagram of an electroluminescent element. Sectional view showing the configuration, No. 6
FIG. 7 and FIG. 7 are cross-sectional views for explaining the prior art. 1...Glass substrate, 2...Transparent conductive film (conductive film),
3... First ever-green layer (ever-green layer), 4... Light-emitting layer 1

Claims (1)

[Claims] A method for manufacturing an electroluminescent element in which a light-emitting layer is laminated on a conductive film with a green-free layer interposed therebetween, characterized in that after the conductive film is formed, a flattening treatment is performed to flatten the conductive film. A method for manufacturing a luminescent element.