JPS62103999A - Manufacture of el device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Summary] This is an improvement in the manufacturing method of an EL element that prevents deterioration of the insulating film between the EL film and the counter electrode (the insulating film of 52) and improves the luminous efficiency and brightness characteristics. be.

After forming the second insulating film, when the EL film is heat-treated,
Since the second insulating film deteriorates and the luminous efficiency and brightness characteristics of the EL element decrease, after forming the ELll, an insulating thin film is formed and the EL film is heat-treated using this as a protective film. This is a method for manufacturing an EL element in which a film is removed and then a second insulating film is formed.

[Industrial application field]

The present invention relates to an improvement in a method for manufacturing an EL element. especially,
The present invention relates to an improvement that prevents deterioration of an insulating film (second insulating film) between an EL film and a counter electrode and improves luminous efficiency and brightness characteristics.

[Conventional technology]

To manufacture an EL film, as shown in FIG. 2, a transparent electrode 2 is formed on a transparent substrate l, a first insulating film 3 is formed on this transparent electrode 2, and E made of a composition of zinc sulfide and a rare earth element or manganese is formed on the first insulating film 3.
The L film 4 is formed, the second insulating film 5 is formed on this EL film 4, and the counter electrode 6 is formed on this second insulating film 5. After forming the EL film 4, It is essential to heat-treat the EL film 4 in any of the steps.

This heat treatment may be performed immediately after forming the EL@4, but the sulfur in zinc sulfide, which is the main base material of the EL film 4, tends to evaporate and create pores, resulting in a decrease in the luminous efficiency of the EL element.
Since the brightness characteristics deteriorate, in order to avoid this, a method of performing heat treatment after forming the second insulator 115I5 is also used.

The present invention is an improvement of this second manufacturing method (a manufacturing method in which heat treatment is performed after forming the second insulating n-barrel 5).

[Problem that the invention seeks to solve]

If heat treatment is performed after forming the second insulating film 11!25, the second insulating film 5 will also be exposed to high temperature at the same time.

The dielectric loss of this second insulating film 5 increases significantly (it is known that in the case of yttrium oxide, the dielectric loss increases by about 10 times), and the luminous efficiency and brightness characteristics of the EL element decrease. There is a risk that it will decrease.

The purpose of the present invention is to eliminate this drawback, and to prevent the deterioration of the EL film due to heat treatment, and also to prevent the deterioration of the insulating film (second insulating film) between the EL film and the counter electrode due to heat treatment. An object of the present invention is to provide a method for manufacturing an EL element that prevents the above problems and improves luminous efficiency and luminance characteristics.

[Means for solving problems]

The means taken by the present invention to achieve the above object are as follows:
Form an insulating thin film after forming the L-film shape.

The EL film is heat-treated using this as a protective film, and after the heat treatment is completed, this protective film is removed, and then the second insulating film is formed.

The material of the insulating thin film that functions as this protective film is ELL
Silicon oxide, silicon nitride, and silicon oxynitride are commonly used as insulating films for children.

In addition to yttrium oxide, lead titanium oxide, barium titanium oxide, tantalum oxide, etc., manganese oxide, manganese sulfide, zinc oxide, aluminum oxide, etc. may also be used.

[Effect]

The gist of Suekan IJ1 is that during the heat treatment of the EL film, a dedicated protective film other than a second insulating film is used to protect the EL film and prevent its deterioration, and then this dedicated protective film that has been damaged by the heat treatment is removed. The purpose is to remove the second insulating film and form an undamaged second insulating film.

Therefore, the function of this dedicated protective film is to reduce the EL during heat treatment.
The purpose is to prevent the sulfur in the zinc sulfide constituting the membrane from vaporizing and forming hollow pores in the EL membrane removal process, and to ensure that the sulfur is removed after the heat treatment is completed. Therefore, the requirements that this dedicated protective film (insulating thin film) should have are: (a) EL
It is stable at the film heat treatment temperature (400 to 500°C), does not allow sulfur to pass through, and prevents evaporation of sulfur in the zinc sulfide that constitutes the EL film;
It does not react with the zinc sulfide that makes up the L film.

(c) Zinc sulfide is not damaged in the process of removing it. Therefore, experiments were conducted on each of the materials listed above, and as shown in the graph of FIG. 3, almost the same remarkable effects were observed with each material.

In the figure, A shows the results of the present invention, and B shows the results of the prior art.

〔Example〕

Hereinafter, with reference to the drawings, an EL device according to an embodiment of the present invention will be described.
The method for manufacturing the device will be further explained.

Refer to Figure 1.1 glass substrate made of ITO etc., with a thickness of about 2,000 mm.
0 using a sputtering method,
Perform the buttering process.

Next, silicon oxide, silicon nitride, silicon oxynitride,
A first insulating film 3 made of yttrium oxide or the like and having a thickness of about 2,000 is formed using a sputtering method.

Next, ELlj14 made of zinc sulfide containing manganese or a rare earth element such as terbium trifluoride or terbium trichloride, which functions as a luminescent center, is coated with a thickness of about 5.0 mm.
Formed to 00 people. A vacuum evaporation method or a sputtering method can be used for this step.

After that, as a protective film according to the gist of the present invention, about t,oo
An insulating thin film is formed to a thickness of o. As mentioned above, the materials for this insulating thin film are silicon oxide, silicon nitride, and yttrium oxide, which are commonly used as insulating films for ELL devices.

In addition to lead titanium oxide, barium titanium oxide, tantalum oxide, etc., manganese oxide, manganese sulfide, zinc oxide, aluminum oxide, etc. may also be used. Sputtering is suitable for forming this insulating thin film.

Thereafter, heat treatment is performed at a temperature of about 500° C. for about 1 hour. In this heat treatment step, the first insulating film 3 is exposed to high temperature, but as a result it is protected by the EL film 4, so that It will not deteriorate.

In the above heat treatment step, the insulating thin film used as a protective film is removed. A dry process is preferable for this removal step, because if a wet process is used, impurities such as moisture may remain on the EL film 4.

Next, silicon oxide, silicon nitride, silicon oxynitride,
A second insulator 11!5 made of yttrium oxide or the like and having a thickness of about 2,000 is formed using a sputtering method.

Finally, a counter electrode 6 made of aluminum or the like is formed and patterned.

The EL element manufactured using the above process has an insulating film (second insulating film) between the EL film and the counter electrode that is not exposed to high temperatures, does not deteriorate, and has a sufficiently small dielectric loss. Therefore, excellent luminous efficiency and brightness characteristics as shown in the third graph are achieved.

〔Effect of the invention〕

As explained above, in the method for manufacturing an EL element according to the present invention, an insulating thin film is formed after forming an EL film, the EL film is heat-treated using this as a protective ia film, and this protective film is removed after the heat treatment is completed. Since the EL film is removed and the second insulating film is then formed, the insulation M (second insulating film) between the EL film and the counter electrode is not exposed to high temperatures and may deteriorate. It also has sufficiently low dielectric loss, achieving excellent luminous efficiency and brightness characteristics.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of an EL film manufactured by carrying out a method for manufacturing an EL element according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of an EL film manufactured by implementing a method for manufacturing an EL element according to the prior art. FIG. 3 is a graph showing the effects of the method for manufacturing an EL element according to one embodiment of the present invention. 1 fist...Glass substrate, 2...Transparent electrode, 3...Φ
First insulating film, 4・Φ・E L j! 9. 5...Fist second insulating film, 6...Counter electrode.

Claims (1)

[Claims] A transparent electrode (2) is formed on a transparent substrate (1), a first insulating film (3) is formed on the transparent electrode (2), and a first insulating film (3) is formed on the transparent electrode (2). An EL film (4) made of a composition of zinc sulfide and a rare earth element or manganese is formed on the first insulating film (3), and a second insulating film (5) is formed on the EL film (4). , in the method of manufacturing an EL element in which a counter electrode (6) is formed on the second insulating film (5), after forming the EL film (4), an insulating thin film is formed and heat treated; A method for manufacturing an EL element, comprising removing an insulating thin film and then forming the second insulating film (5).