JPH0675433B2 - Thin film EL device and method of manufacturing the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a thin film EL (electroluminescence is referred to as EL in this specification) element and a manufacturing method thereof, and in particular, a multi-color EL element that emits light in a plurality of colors. The present invention relates to a thin-film EL device suitable for the above and a manufacturing method thereof.

(Prior Art) A conventional multi-color thin film EL element has been manufactured by a process as shown in FIGS. That is, the transparent electrode layer 2 is formed on the substrate 1, and the first dielectric layer 3 is formed on the transparent electrode layer 2. The first phosphor layer 4 (a) is formed on the first dielectric layer 3, and the first phosphor layer 4 (a) is patterned with the photoresist 10 to form the first phosphor layer 4 (a). Chemically etching (a) (FIG. 2 (a)). After that, with the resist pattern left, the second
The phosphor layer 4 (b) is formed and the resist is washed away (lift-off method) (FIG. 2 (b)). Third phosphor layer 4
Similarly for (c), a plurality of phosphor layers 4 (a), 4
(B) and 4 (c) are formed on the same plane, the second dielectric layer 5 is formed on the phosphor layer, and the back electrode 6 is formed on the second dielectric layer 5. (FIG. 2 (c)).

(Problems to be Solved by the Invention) In the conventional thin-film EL device as described above, the first phosphor layer is (n-1) times formed with the resist pattern and etched, where n is the type of the phosphor layer. However, there is a problem in that the phosphor is exposed to water by washing with water during pattern formation, an etching solution by chemical etching, and washing with water, which causes deterioration and peeling of the phosphor.

An object of the present invention is to provide a multi-color thin film EL element that does not cause deterioration or peeling of a phosphor.

(Means for Solving the Problem) In the invention of the first claim, a plurality of phosphor layers having different emission colors are formed between the first dielectric layer and the second dielectric layer, and And a multi-color thin film EL element in which at least one outer side of the second dielectric layer is an electrode made of a transparent conductor, a plurality of phosphors arranged in a desired pattern in a plane on the first dielectric layer. The layer is embedded in the third dielectric layer.

According to a second aspect of the invention, a plurality of phosphor layers having different emission colors are formed between the first dielectric layer and the second dielectric layer, and at least the first and second dielectric layers are formed. In a method of manufacturing a multi-color thin film EL device, one outer side of which is an electrode made of a transparent conductor, a third dielectric layer is formed on the first dielectric layer, and a resist is formed on the third dielectric layer. After forming the pattern, the third dielectric layer is vertically etched, followed by forming a phosphor layer on the surface, then forming a fourth dielectric layer on the phosphor layer, and then removing the resist layer. It is characterized by that.

(Operation) According to the invention of the first aspect, the phosphor layer is embedded in the third dielectric layer. According to the second aspect of the invention, after the third dielectric layer is etched, the phosphor layer is formed on the surface of the third dielectric layer, and the fourth dielectric layer is formed on the phosphor layer. Substantially embedded in the third dielectric layer. For this reason, the phosphor layer is not exposed to water due to washing with water when forming the pattern of the third dielectric layer, an etching solution by chemical etching, and washing with water.

Therefore, peeling and deterioration of the phosphor layer due to washing with water will not occur.

(Examples) Hereinafter, the present invention will be described with reference to Examples.

FIG. 1 (c) is a cross-sectional view showing a thin film EL element of one embodiment of the present invention, showing an example of a thin film EL element which emits light of three colors.

In the thin film EL device of this embodiment, the first dielectric layer 3 is formed on the transparent electrode 2 formed on the substrate 1. A plurality of phosphor layers 4 (a), 4 (b) and 4 (c) having different emission colors are formed between the first dielectric layer 3 and the second dielectric layer 5.

The plurality of phosphor layers 4 (a), 4 (b), and 4 (c) are formed on the first dielectric layer 3 between the first dielectric layer 3 and the second dielectric layer 5. Phosphor layers 4 (a), 4 (b) and 4 (c) arranged in a desired pattern in the plane are formed between the first dielectric layer 3 and the second dielectric layer 5. It is embedded in the third dielectric layer 7.

Therefore, when forming the phosphor layer in a desired pattern, for example, washing with water after development of a positive resist (AZ series, OFPR series),
The effect on the phosphor layer due to washing with water after the lift-off process using the rimbar solution and the organic solvent, that is, the peeling and deterioration of the film can be completely prevented. This can be understood from the embodiment of the manufacturing method described below.

1 (a) to 1 (C) are cross-sectional views showing a manufacturing process of a thin film EL element according to an embodiment of the present invention.

After forming the transparent electrode 2 in a desired pattern on the substrate 1, the first dielectric layer 3 is formed on the transparent electrode 2. After the formation of the first dielectric layer 3, the third dielectric layer 7 is formed on the first dielectric layer 3 so as to have a thickness (0.2 to 1.0 μm) or more of the phosphor layer 4. The third dielectric layer 7 is formed of CF ₄ , CF ₄ + H ₂ , CF ₄ + in a reactive ion etching (RIE) device such as SiOx or SiONx.
It is preferable to use a material that can be easily etched with O ₂ gas so that the first dielectric layer 3 is not etched with the above gas.
Extremely good ones Do A _L2 O _3, Ta ₂ material of O ₅ such small etching rate. A resist pattern 10 is formed on the third dielectric layer 7 (Fig. 1a). After forming the resist pattern 10, the third dielectric layer 7 is vertically etched by the RIE apparatus. This etching may be chemical etching such as hydrofluoric acid. After this etching, the first phosphor layer 4
(A) is formed by vapor deposition or sputtering, and then a fourth dielectric layer 8 is formed on the first phosphor layer 4 (a) (FIG. 1 (b)). Next, the register layer 10 is removed by organic solvent, rim bar solution, plasma ashing, etc.
off).

Similarly, the second phosphor layer 4 (b) and the 4'th dielectric layer 8 '
Are embedded in the third dielectric layer 7 with the third phosphor layer 4 (c) and the fourth "dielectric layer 8". Then on this second
And the back electrode 6 is formed on the second dielectric layer 5 (FIG. 1 (c)). Therefore, the phosphor layers 4 (a), 4 (b) and 4 (c) are embedded in the third dielectric layer 7.

(Effects of the Invention) As described above, according to the present invention, since the phosphor layer is formed in a desired pattern and the fourth dielectric layer is formed thereon, for example, a positive resist (Az series, OFPR series) is used. ) Washing with water after development, washing with rimbar solution, washing with lift-off process with organic solvent, etc. does not affect the phosphor layer, and peeling and deterioration of the phosphor layer film should be completely prevented. You can
The side surface is completely protected by the third dielectric and the upper surface is completely protected by the fourth dielectric.

Therefore, it is possible to completely prevent the influence of water on the phosphor layer at the time of manufacturing the thin film EL element, so that the yield can be improved and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a thin film EL element according to the present invention. FIG. 1 (a) shows a state until a resist pattern is formed by etching a third dielectric layer, and FIG. Of the first phosphor layer and the state until the fourth dielectric layer is formed.
FIG. 6C is a sectional view showing a state up to formation of a back electrode. FIG. 2 is a cross-sectional view showing a conventional thin film EL element.
FIG. 2A shows a state up to formation of a resist pattern for etching the first phosphor layer, FIG. 2B shows a state up to formation of the second phosphor layer, and FIG. 2C. [FIG. 3] is a cross-sectional view showing a state up to formation of a back electrode. 1 ... Substrate, 2 ... Transparent electrode, 3 ... First dielectric layer,
4 (a), 4 (b) and 4 (c) ... first, second and third phosphor layers, 5 ... second dielectric layer, 6 ... rear electrode, 7 ... third Dielectrics, 8, 8'and 8 "... 4th
Dielectric, 10 ... resist.

Claims (2)

[Claims] 1. A plurality of phosphor layers having different emission colors are formed between a first dielectric layer and a second dielectric layer, and at least one outer side of the first and second dielectric layers. In a multi-color thin film EL element in which is an electrode composed of a transparent conductor, a plurality of phosphor layers arranged in a desired pattern in a plane on the first dielectric layer are embedded in a third dielectric layer. Thin film EL device characterized by 2. A plurality of phosphor layers having different emission colors are formed between a first dielectric layer and a second dielectric layer, and outside at least one of the first and second dielectric layers. In the method for manufacturing a multi-color thin film EL element, in which is an electrode made of a transparent conductor, a third dielectric layer is formed on the first dielectric layer, and a resist pattern is formed on the third dielectric layer. After that, the third dielectric layer is vertically etched, a phosphor layer is subsequently formed on the surface, a fourth dielectric layer is formed on the phosphor layer, and then the resist layer is removed. Method for manufacturing thin film EL device.