JPH01276592A - Manufacture of multi-color display thin film el element - Google Patents

Abstract

PURPOSE:To obtain a multi-color display thin film EL element containing a luminous film made of an alkaline earth metal by continuously overlapping and forming insulating films and luminous films, performing photo-etching processing and lift-off processing on both films, and plane-arranging luminous films. CONSTITUTION:The first insulating film 25 is formed on a glass substrate 26 and a transparent electrode film 24, the first luminous film 26 and the second insulating film 27 are overlapped and formed on it. A photo-resist pattern 28 is formed on the insulating film 27 by photo-etching, the second insulating film 27 and the first luminous film 26 are etched using it as a mask, the second luminous film 29 is formed on the remaining photo-resist pattern 28 and the first insulating film 25. The first - fourth insulating films 25, 27, 30 and the first - third luminous films 26, 29, 32 are aligned with no gap and without being overlapped each other. After the third luminous film 32 is photo-etched, the fifth insulating film 34 is formed, a back electrode 35 made of an Al film is formed on the insulating film 34, photo-etching processing is performed in a fine line pattern. A thin film EL element is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method of manufacturing a thin film EL element capable of displaying a plurality of colors.

[Conventional technology]

With the development of the information society, the importance of display terminal devices is increasing. In particular, there is a strong desire to realize a flat display device that is thin and lightweight, and for this reason, various types of flat display devices are actively researched and developed. Among them, thin film E
L (electroluminescent) elements have advantages such as being highly reliable as they are all-solid-state devices, and are self-luminous and have excellent display quality, making them the most promising candidates for future flat display devices. It is expected that it will become possible.

In principle, a thin film EL element has a structure as shown in FIG. 9, in which manganese (M n ) or rare earth metals (Tb, S
Zinc sulfide (ZnS) or zinc selenide (ZnSe) added with m, Tm, Pr, Dy, Eu, Ce)
), a luminescent film 2 made of strontium sulfide (SrS), calcium sulfide (CaS), barium sulfide (BaS), etc., and an insulating film 3 provided for the purpose of maintaining insulation, are combined with a transparent electrode film 4 and a metal electrode film 5. It is made up of a sandwich in the shape of an inch. In the element configured in this manner, when an alternating current electric field is applied between the transparent electrode film 4 and the metal electrode film 5, the light emitting film 2 emits light, which is observed as a color display from the outside of the transparent substrate 1. . Then, the transparent WA film 4
If the metal electrode film 5 is processed into a thin line shape 1 and an electric field is applied line by line, high-definition characters and figures can be displayed.

The display color is determined by the base material of the light-emitting film 2 and the substances added to it.
When + is added, the light is emitted in yellow, green, red, and blue, respectively, and when Ce and Eu are added to the SrS film, the light is emitted in blue and green, respectively. Furthermore, it is known that when a CaS film is used as a light-emitting film host material and Ce and Eu are added thereto, the film emits green and red light, respectively. However, although materials with various luminescent colors have become available, the one currently in practical use is a ZnS film with M
It is only a monochromatic display element that emits yellow light using a light-emitting film doped with n. This is because, in addition to the development of constituent materials, the device configuration and manufacturing process, which are key to manufacturing, have not been established for multicolor display thin film EL devices.

Conventionally, there are two methods described below as methods for realizing light emission of two or more colors using the same element.

The first method is Y, Oishi, T, Kato
and Y.

Hamakawa's technical digest of.

1983 ・Japan Display (Technic
alDigest of 1983 Japan Di
This is a method of stacking elements of different luminescent colors, as described in Spray) p., 570 (1983).

FIG. 10 is a cross-sectional view of a thin film EL device manufactured by the above method. In FIG. 10, 6 is a glass substrate, 7 is a first transparent electrode film, 8 is a first insulating film, 9 is a first light emitting film, 1
0 is the second yAa film, II is the second transparent electrode film, 12 is the third insulating film, 13 is the second light emitting film, 14 is the fourth insulating film, and [5 is the back electrode.

The second method is a method filed by one of the inventors and is described in Japanese Patent Application No. 1983-211940. As shown in FIG. 11, the above method includes sequentially forming a transparent electrode film 17 and a first insulating film 18 on a glass substrate 16, and then forming a first light emitting film formed on the first insulating film 18. 19 is patterned by a wet photoetching process using an acidic etching solution mainly containing nitric acid, and then the second light emitting film 2 is formed with the photoresist h remaining.
0 is formed, patterned through the riff 1 to off steps, and then the second insulating film 21 and the back electrode 22 are sequentially formed to finally form two or more types of light emitting films on the same chain plate. The aim is to realize a structure in which the elements are arranged in a plane.

[Problem to be solved by the invention]

The first method described above has the disadvantages that the electrode extraction for connecting the electrode to an external circuit becomes extremely complicated, and the configuration of the immediate action circuit becomes extremely complicated. It is difficult to apply it to devices. Furthermore, using the above method, the three types of emitting colors necessary for full color display (
It is impossible to construct a multicolor display thin film EL element capable of high-definition display by stacking red, green, and blue elements because there is no effective means for taking out the electrodes to the outside.

On the other hand, in the second method, the electrode wiring for supplying electricity to make the device emit light is basically the same as that of a monochromatic thin film EL device, so the structure is easy, and the second method is a self-emitting method that uses a combination of photoetching and lift-off. Since it is an alignment process, it has the advantage that high-definition light-emitting pixels can be manufactured without pattern misalignment, and there is no problem in arranging three types of light-emitting films and taking out electrodes for full-color display.

This method can be said to be superior to the first method described above for constructing a multicolor display thin film EL element. However, the second method has the following problems, and cannot be said to be a perfect method.

First, alkaline earth-based light-emitting films such as SrS and CaS have higher luminous efficiency than ZnS-based light-emitting films as blue and red EL, and have recently been expected to be promising materials for multicolor display thin-film EL elements. Since these materials have high reactivity with moisture and are easily oxidized, the above materials can be used to produce multicolor display thin films E.
When attempting to manufacture an L element, the second method described above, in which a resist is applied directly to the light-emitting film, exposed and developed, cannot be applied because the light-emitting film oxidizes and deteriorates during the photo-etching process. Therefore, there is a problem that the materials used are limited. Secondly, it is a well-known fact that in thin-film EL devices, the interface of the emissive layer in contact with the insulating film and electrodes makes an important contribution to the luminescent properties. Since this method involves direct coating and heat treatment and peeling treatment, there is a problem in that the interface between the light emitting film and the insulating film is contaminated, resulting in deterioration of the light emitting characteristics.

An object of the present invention is to solve each of the above-mentioned problems and to obtain a manufacturing method that makes it possible to realize a multicolor display thin film EL element including an alkaline earth-based light emitting film.

[Means to solve the problem]

The above purpose is to first sequentially form an insulating film and a light-emitting film, and then perform photo-etching and lift-off processing on both films to fabricate a thin film EL element with a structure in which the light-emitting films are arranged in a plane. This can be achieved by

[For production]

1 to 7 showing the manufacturing process of the present invention will be explained. In FIG. 1, after a transparent electrode film 24 is formed on a glass substrate 23, a first insulating film 25 is formed on the upper surfaces of the glass substrate 23 and the transparent electrode film 24. The first insulating film 25 includes a Ta205 film, a 5M203 film, a Si film, a N film, and an S film, which are resistant to acid-based etching solutions.
io, membranes and combinations of these membranes can be used. Next, on the upper surface of the first insulating film 25,
For example, Ce-added 5rS (hereinafter referred to as SrS: Ce)
The first light emitting film 26 consisting of
It is formed by a VD method, a sputtering method, or the like. Subsequently, a second insulating film 27 is formed on the light emitting film 26 by a CVD method or a sputtering method. As for the material of the second insulating film 27, a thin film material that can be easily dry-processed, such as Si,
N4. Sio2 is desirable. Next, a photoresist pattern 28 is formed on the second insulating film 27 by a photoetching process.
The second insulating film 27 and the first light emitting film 26 are etched using the photoresist pattern 28 as a mask to obtain a cross-sectional structure as shown in FIG. Here, the second insulating film 27 can also be etched by immersing it in a hydrofluoric acid-based liquid, but in order to prevent the glass substrate 23 from being eroded, etching only the second insulating film 27 can be done selectively. And to perform with good controllability, use CF4. Dry etching using gas plasma such as C4F is most desirable. Also, the first
The etching of the luminescent film 26 is performed using a gas containing chlorine, that is, a mixed gas of CF4 and CQ2, ct42F2, CCL.
A dry etching method using plasma discharge in a gas such as , BCR, or SiC is optimal.

In addition, a mixture containing nitric acid as the main ingredient, phosphoric acid, acetic acid, and water to adjust the etching rate;
Alternatively, a wet etching method using hydrochloric acid as an etching liquid can also be used since the insulating film 27 exhibits a sufficient interface protection effect.

Next, with the photoresist pattern 28 remaining, the remaining photoresist pattern 28 and the first insulating film 2 are removed.
A second light-emitting film 29 made of, for example, an Eu-doped CaS (CaS:Eu) film is formed on the film by electron beam evaporation, sputtering, or MOCVD, and then a second light-emitting film 29 made of, for example, a Si3N4.3i○2 film is formed on the film. A third insulating film 30 is formed by CVD or sputtering to obtain a structure as shown in FIG.

Next, the glass substrate 23 treated as described above is immersed in a resist stripping solution to remove the photoresist pattern 28, thereby removing the second light emitting film 29 and the third insulating film 3.
0 is subjected to lift-off processing to obtain a structure as shown in FIG. Through this step, the first light emitting film 26 and the second light emitting film 29 can be arranged on the glass substrate 23 without any gaps and without overlapping each other.

Next, a photoresist pattern 31 is formed on the second and third insulating films 27 and 30 by a photoetching process, and then, when forming the pattern shown in FIG. By photo-etching the second insulating film 27 and the third insulating film 30, or both of the second insulating film 27 and the third insulating film 30, and the first light-emitting film 26 and the second The structure shown in FIG. 4 is obtained by etching one or both of the light emitting film 29 and the light emitting film 29. Subsequently, on the first insulating film 25 and the photoresist pattern 31, sputtering method, MOC
A third light-emitting film 3 made of, for example, Ce-doped CaS (CaS:Ce) is formed by a VD method or an electron beam method.
2 and a fourth film made of, for example, Si3N4.5in2 film.
An insulating film 33 is formed by CVD or sputtering to obtain a structure as shown in FIG.

By immersing the glass substrate 23 treated as described above in a resist stripping solution to remove the photoresist pattern 31, the third light emitting film 32 is subjected to a lift-off process to obtain a structure as shown in FIG. 6. . Through this step, the first light emitting film 26, the second light emitting film 29, and the third light emitting film 32 can be arranged on the glass substrate 23 without any gaps and without overlapping each other.

Next, the second to third and fourth insulating films 27.30.3
A fifth insulating film 34 is formed on the upper surface of each of the electrodes 3.

The fifth MA edge film 34 includes Ta2O, film, Al
120. membranes, Si3N4 membranes, Sio2 membranes, and combinations of these membranes can be used. Note that the fifth insulating film 34 is not necessarily required since there are second, third, and fourth insulating films. However, in order to easily carry out the photo-etching process of the second and third light emitting films 29.32 and the riff 1 to off process, the second, third and fourth insulating films 27.30
．． 33 preferably has a film thickness of 1100 nm or less, so from the viewpoint of increasing the device breakdown voltage, it is better to insert the fifth insulating film 34 after photoetching the third light emitting film 32. Finally, a back electrode 35 made of, for example, a thin film is formed on the upper surface of the fifth insulating film 34 and photoetched into a fine line pattern, thereby completing a thin film EL element having a cross section as shown in FIG. , its manufacturing process is completed.

Here, as mentioned above, in the detailed explanation of the present invention, the SrS:Ce film, CaS:
Both the Eu film and the CaS:Ce film have the property of reacting with moisture and easily causing oxidative deterioration.

Therefore, thin film EL devices using these films cannot withstand the photo-etching process, and therefore cannot be manufactured as high-definition multicolor display devices using conventionally known methods. However, if the method of the present invention described above is used, that is, a method in which an insulating film is further formed on these thin films and processed by dry etching using plasma discharge, these light emitting films can be processed without causing any deterioration. Photoetching processing becomes possible, and a multicolor display element composed of three types of light emitting films can be manufactured as shown in FIG.

According to the thin film EL device shown in FIG. 7 above, the transparent electrode 24
By applying an alternating current electric field between and the back electrode 35, the first light emitting film 2 made of SrS:
6 is blue, the second light emitting film 29 made of CaS:Eu film is red, and the third light emitting film 3 made of CaS:Ce film is shown in red.
2 emits green light. Therefore, the thin film EL with the above configuration
Since the device can emit light in three primary colors, the intensity of light emitted from each light-emitting film can be adjusted by adjusting the applied voltage.
It is possible to realize multi-color display with more than one color.

Note that the light-emitting films 26, 29, and 32 are not limited to the above-mentioned materials; for example, as a red light-emitting film, S
m-doped ZnS (ZnS: Sm), Tm-doped ZnS (ZnS: Tm) for the blue light-emitting film, and Tb-doped ZnS (ZnS: Tb) for the green light-emitting film.
etc. can also be used. Note that Zn is used as a light emitting film.
Regarding the layer using the S film, since the ZnS film does not undergo rapid deterioration even when wet photoetching is performed, the method disclosed in Japanese Patent Application No. 61-211940, that is, forming an insulating film on the light emitting film, is used. The light-emitting film may be patterned through a photo-etching process instead of being formed continuously. Further, even if two types of light emitting films are used, a multicolor display element capable of displaying three or more colors can be realized.

To fabricate an element composed of the above two types of light emitting films,
Of the manufacturing steps shown in FIGS. 1 to 6 above, the manufacturing steps related to FIGS. 4, 5, and 6 may be omitted.

〔Example〕

Next, embodiments of the present invention will be described with reference to the drawings.

1 to 6 are cross-sectional views showing the manufacturing process of a multicolor display thin film EL device according to the present invention, and FIGS.
The figures are device cross-sectional views showing examples of thin film EL devices manufactured by the above manufacturing process.

In FIG. 1 of the first embodiment, the glass substrate 23 has a thickness of 1.2+
A transparent electrode film 24 of ITO (tin-added indium oxide, In2O, :Sn) with a film thickness of 1100 nm is formed on the glass substrate 23 using NA40 glass (manufactured by HOYA), which is a trade name of a.
was formed by high-frequency sputtering, and a thin wire-like electrode structure was formed by photoetching.

Next, a T film with a thickness of 200 nm was made by high-frequency sputtering method.
a, O, membrane and electron cyclotron resonance (ECR) CV
The first insulating film 25 was formed by sequentially stacking SL and N4 films with a film thickness of 1100 nm using the D method. Next, a first light-emitting film 26 made of an SrS:Ce film with a film thickness of 600 nm is formed by electron beam evaporation, and a film with a film thickness of 1100 nm is formed by ECR-CVD.
A second insulating film 27 made of a Si3N4 film of n is sequentially formed, and a positive resist (trade name Microposit 1400
-27) to form a photoresist pattern 28, and then first SL, N
, dry etching the film 27, then CCf12F2
The SrS:Ce film 26 was etched by plasma using gas. The dry etching processing conditions at this time were: discharge power 200-300W, gas flow rate 50-150W.
secn+, pressure 0.5 to 1.5 Torr, processing temperature 4
A temperature of 0°C to 80°C and a treatment time of 10 minutes or less were suitable.

Note that wet etching was also performed for etching the SrS:Ce film, and patterning was also possible with this method. The composition of the etching solution at this time is that the concentration of hydrochloric acid is 10
~20% by weight dilute hydrochloric acid was optimal.

Next, while leaving the photoresist pattern 28, a second light-emitting film 29 made of CaS:Eu with a film thickness of 600 nm is formed by electron beam evaporation, and a film with a film thickness of 11 nm is formed by ECR-CVD.
00n Si and N4 films 30 were sequentially formed. Next, the glass substrate 23 is immersed in a resist stripping solution (trade name: Microposit Remover 140), and the photoresist pattern 28 is removed by applying ultrasonic waves to form a CaS:Eu film 29, which is a second light emitting film. and third insulating film 3
A photoresist pattern 31 is formed using Microposit 1400-27 (trade name) in a photoetching process, and a second photoresist pattern 31 is formed in the same manner as when the first light emitting film 26 and the second insulating film 27 are etched. The light emitting film 29 and the third
The insulating film 30 was photoetched. Next, while leaving the photoresist pattern 31, a third film made of CaS:Ce with a thickness of 600 nm is formed by electron beam evaporation.
SL, N4 film 33 is formed as a fourth insulating film by the ECR-CVD method, and then the glass substrate 23 is immersed in a resist stripping solution (trade name: Microposit Remover 140), and then subjected to ultrasonic wave treatment. By applying , the photoresist pattern 31 is removed and the third light emitting film 3
The second and fourth Ma films 33 were photoetched.

Next, a film thickness of 300 nm was obtained by high-frequency sputtering method.
A fifth insulating film 34 made of a Ta205 film with a thickness of 200 nm is formed, followed by an M back electrode film 35 with a film thickness of 200 nm, and the M back electrode film 35 is photoetched into a thin line shape. A film EL device with a cross-sectional structure as shown in the figure was completed.

In the thin film EL device shown in FIG. 7 above, the transparent electrode film 2
When an AC voltage of 150 cm with a frequency of 1 kHz was applied between the back electrode film 35 and the back electrode film 35, the first. The second and third light-emitting films 26, 29, and 32 each emitted blue, red, and green light with a luminance of 200 cd 7 m2 or more. In addition, the electrode film 24
and 35, by appropriately selecting the voltage application points and observing the mixed colors of the emitted light from the light emitting films 26, 29, 32, blue, light blue, green, yellow, red, pink,
A total of 7 colors of light emitting display including white could be performed. Also,
There was no failure of the device due to peeling of the thin film due to the photoetching process or dissolution of the thin film due to penetration of the etching solution.

Second Example Glass substrate 23 with thickness 1, 2 + m+, product name 7
Glass substrate 2 using 059 glass (manufactured by Corning)
An IT◯ transparent electrode film 24 having a film thickness of 1100 nm was formed on the substrate 3 by high frequency sputtering, and a thin wire-like electrode structure was formed by photoetching. Next, a Ta205 film with a thickness of 200 nm and an ECR-C
Si3N4 films with a film thickness of 1100 nm were sequentially laminated using the VD method,
A first insulating film 25 was formed. Next, a first light-emitting film 26 made of an SrS:Ce film with a film thickness of 600 nm was formed by electron beam evaporation, and a film with a film thickness of 11 nm was formed by ECR-CVD.
A second insulating film 27 consisting of a 00n SL film and an N4 film was sequentially formed. Next, a photoresist pattern 28 is formed using a positive resist (trade name Microposit 1400-27), and then the 5L3N film 27 is first dry etched using plasma using CF4 gas, and then the film 27 is etched using CF4 gas. The SrS:Ce film 26 was etched by plasma using a gas mixed with chlorine at a concentration of 50%. The dry etching processing conditions at this time are discharge power 200 to 300W, gas flow rate 5050-1
50se, pressure 0.5-1.5 Torr, processing temperature 40
C. to 80.degree. C. and treatment time within 10 minutes was appropriate. Regarding the etching of the SrS:Ce film.

I also used wet etching, but was able to create a pattern even with this method. The etching solution at this time has a nitric acid concentration of 2 to 50% by weight.
Nitric acid, phosphoric acid, acetic acid, and a mixture of these with water were used.

Next, while leaving the photoresist pattern 28, a Mn-doped ZnS film with a thickness of 700 nm is deposited by electron beam evaporation.
A second light emitting film 29 made of (ZnS:Mn) was formed. Then, the glass substrate 23 is immersed in a resist stripping liquid (trade name: Microposit Remover 140), and ultrasonic waves are applied to remove the photoresist pattern 28.
was removed, and the ZnS:Mn film 29, which is the second light emitting film, was photoetched.

After that, a film thickness of 300 nm was formed by high frequency sputtering method.
A third insulating film 34 made of a Ta205 film is formed, followed by a growth surface electrode 35 having a film thickness of 200 nm.

Furthermore, by photoetching into fine lines,
A thin film EL device with a cross-sectional structure as shown in FIG. 8 was completed.

In the thin film EL element, an AC voltage of 150 V with a frequency of 1 kHz is applied between the transparent electrode film 24 and the M back electrode film 35.
When this was applied, the first and second light-emitting films 26 and 29 each emitted blue and yellow light with a luminance of 200 cd/rrr or more. In addition, by appropriately selecting the voltage application points in the electrode films 24 and 35 and observing the mixed colors of the emitted light from the light emitting films 26 and 29, it is possible to perform a three-color display of blue, yellow, and white. did it. Moreover, no element failures such as peeling of the thin film caused by the photoetching process or dissolution of the thin film due to penetration of the etching solution occurred.

It should be noted that the method for manufacturing a thin film EL element described above is merely one embodiment of the present invention, and it goes without saying that various changes and improvements can be made without departing from the spirit of the present invention.

〔Effect of the invention〕

As described above, the method for manufacturing a multicolor display thin film EL element according to the present invention includes a plurality of band-shaped transparent electrodes disposed on a transparent insulating substrate, and three strip-shaped transparent electrodes disposed on a transparent insulating substrate, and three
In the method for manufacturing a multicolor display thin film EL device, in which different types of light emitting films are formed, and a back electrode is further disposed on each of the light emitting films via an insulating film, the first light emitting film and the insulating film are continuously formed. a first step of forming a layer, a second step of patterning the first light emitting film and the insulating film by photoetching;
a third step of successively forming a second light emitting film and an insulating film on the substrate while leaving the photoresist used in the photoetching; and a third step of forming a second light emitting film and an insulating film on the substrate; a fourth step of lift-off processing the first and second light emitting films and the insulating film; a fifth step of patterning at least one of the first and second light emitting films and the insulating film by photo-etching; A sixth step of successively forming a third light-emitting film and an insulating film on the substrate while leaving the photoresist; and removing the photoresist used in the fifth step; SrS, which has attracted particular attention in recent years as a color EL material, solves the problems associated with the production of conventional multicolor display thin film EL elements. Since it is also possible to realize a multi-color display 7N and film EL element containing an alkaline earth light emitting film such as CaS, the manufacturing method of the present invention has the effect of realizing a high-definition full-color flat display device using a thin film EL element. . Note that the same effect can be obtained by the manufacturing method of the present invention when a multicolor display thin film EL element is manufactured by forming two types of light emitting films on a transparent electrode.

[Brief explanation of the drawing]

1 to 6 are cross-sectional views showing each manufacturing process of a multicolor display thin film EL device according to the present invention. Figure 7 shows a multicolor display thin film EL manufactured by the above manufacturing process.
FIG. 8 is a cross-sectional view of the device showing the first embodiment of the device, FIG. 8 is a cross-sectional view of the device showing the second embodiment of the thin film EL device, FIG. 9 is a cross-sectional view explaining the principle of the thin film EL device, and FIG. FIG. 11 is an element sectional view showing one conventional example of the thin film EL element, and FIG. 11 is an element sectional view showing another conventional example of the thin film EL element. 23... Insulating substrate 24... Band-shaped transparent electrode 25... First insulating film 26... First light emitting film 27... Second insulating film 29... Second light emitting film 30 ...Third insulating film 32...Third light emitting film 35...Back electrode patent originator Nippon Telegraph and Telephone Corporation

Claims (2)

[Claims] 1. A plurality of band-shaped transparent electrodes are arranged on a transparent insulating substrate, three types of light emitting films are formed on the transparent electrodes either directly or through an insulating film, and further on each of the light emitting films is formed with an insulating film interposed therebetween. A method for manufacturing a multicolor display thin film EL device provided with a back electrode includes a first step of successively laminating a first light emitting film and an insulating film; a second step of patterning by photoetching; a third step of successively forming a second light emitting film and an insulating film on the substrate while leaving the photoresist used in the photoetching; a fourth step of lifting off the second light emitting film and the insulating film by removing the photoresist; and patterning at least one of the first and second light emitting films and the insulating film by photoetching. a fifth step; a sixth step of successively forming a third light emitting film and an insulating film on the substrate while leaving the photoresist used in the fifth step; A method for manufacturing a multicolor display thin film EL device, comprising a seventh step of lifting off the third light emitting film and the insulating film by removing the photoresist used in the step. 2. A plurality of band-shaped transparent electrodes are arranged on a transparent insulating substrate, two types of light emitting films are formed on the transparent electrodes directly or through an insulating film, and further, two types of light emitting films are formed on each of the light emitting films with an insulating film interposed therebetween. A method for manufacturing a multi-color display thin film EL device provided with a back electrode includes the steps of: successively laminating a first light-emitting film and an insulating film, and then patterning the laminated film by photo-etching; A step of successively forming a second light emitting film and an insulating film on the substrate while leaving the photoresist used for etching, and a step of removing the photoresist and forming the second light emitting film and the insulating film. A multicolor display thin film EL characterized by including a step of lift-off processing.
Method of manufacturing elements.