JPS61131396A - Manufacture of electrode substrate - 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] (Industrial application field) The present invention relates to a method for manufacturing an electrode substrate.

This electrode substrate is made of El (Electro Lum1
nescence) LCD, ECD (Electr
o Chrolc Display ) and EPIO (
Electro Phoretic tmaoe Di
It is used for display elements such as display devices and other elements.

[Prior art and its problems] For example, as shown in FIG. 2, as a method for manufacturing an electrode substrate for an EL display element, an ITO film (mainly made of indium oxide) is formed on one main surface of a transparent substrate 1 such as glass. Indium Tinoxttie mixed with tin oxide as a component
means. ), etc., and this transparent conductive 1N!
A transparent electrode 2 is formed by selectively patterning.

EL display elements and the like have recently become larger and have higher resolution, and in order to achieve this, transparent electrodes with lower resistance are required. However, since the resistance value of the transparent electrode is about 10-4Ωα as a specific resistance, the longer the length of the transparent electrode, the more
The signal voltage applied from one terminal is significantly attenuated. One possible means of maintaining the resistance value of such a transparent electrode low is to increase its film thickness, but the third
In the structure of the EL display element shown in the figure, when the film thickness of the transparent electrode 2 is made thicker than usual, its side surface portion 3 protrudes almost perpendicularly to the transparent substrate 1, and a stepped surface is also formed in the film on the upper layer. Resulting in. That is, after forming the transparent electrode 2, a first electric layer 4 made of Y2O3, Ta205, etc., and a 0.00. -1 to 2.0 weight ω% f4n
(or Tn+, Yb, Er, Sm, C
u.

Aj! , Br, etc.) doped with ZnS (or Zn
5e, etc.); Ding a20
An EL display element is manufactured by sequentially forming a second dielectric layer 6 made of 5 or the like and a back electrode 7 made of An or the like.
When a voltage is applied between the transparent electrode 2 and the back electrode 7 to generate EL light, the electric field is concentrated near the edge of the transparent electrode 2 and the side surface 3, so dielectric breakdown is likely to occur from the edge. There were some drawbacks.

For the above-mentioned drawbacks, the side surface portion 3 of the transparent electrode 2 is
There is a proposal to form an inclined surface of about 5 degrees, but although this may improve dielectric breakdown to some extent, it cannot be a fundamental countermeasure.

Next, as a method for manufacturing an electrode substrate, a method has been proposed in which conductive parts 10 and non-conductive parts 11 are arranged alternately on a substrate 1 as shown in FIG. -765
05). This proposal first involves forming a transparent conductive film 8 on one main surface of the substrate 1 (FIG. 5(a)), coating a resist layer on this transparent conductive film 8, and exposing it to light in a predetermined pattern.
It is developed to form a resist pattern 9 (Figure (b)).
By using this resist pattern 9 as a mask and processing it in an oxidizing atmosphere, the masked transparent conductive film 8 is removed.
The portion marked with is made into a conductive part 10 that becomes a transparent electrode, and the unmasked part is made into a non-conductive part 11 (FIG. 1C). Next, the resist pattern 9 is removed to obtain an electrode substrate (FIG. (d)).

However, according to this proposal, since the treatment is carried out in an oxidizing atmosphere, the resistance value of the conductive part 10 that becomes the transparent electrode becomes about 10% higher than the original value, which has the disadvantage of deteriorating the conductivity of the transparent electrode. Ta. Further, the boundary between the conductive part 10 and the non-conductive part 11, which become transparent electrodes, extends to the part where the upper layer of the non-conductive part 11 is covered with the resist pattern 9, as shown in FIG. The width of the upper layer tends to be narrower than that of the lower layer (substrate 1 side). This tendency becomes more pronounced as the thickness of the transparent conductive film 8 (the conductive part 10 that becomes the transparent electrode) becomes thicker, and at the same time it reduces the precision of patterning. It had the disadvantage of not being able to meet demands.

[Purpose of the invention]

The present invention has been made to solve the problems in the conventional electrode substrate manufacturing method as described above, and the first object of the present invention is to reduce the resistance of a transparent conductive film (transparent electrode). The second objective is to provide a method for manufacturing an electrode substrate that does not reduce the value of the electrode substrate, and a second purpose is to provide a method for manufacturing an electrode substrate that does not form edges that cause dielectric breakdown. Yes, the third purpose is transparent conductive film (transparent electrode)
An object of the present invention is to provide a method for manufacturing an electrode substrate that can improve patterning accuracy.

[Means for solving problems]

In order to achieve such an object, the method for manufacturing an electrode substrate of the present invention includes selectively patterning a transparent conductive film deposited on one main surface of the substrate to form a transparent electrode pattern,
The present invention is characterized in that a transparent insulating film pattern is embedded in the exposed portion on one main surface of the substrate (the substrate surface portion between adjacent transparent electrode patterns). In a preferred embodiment, the patterns of the transparent electrodes and the transparent insulating film are arranged alternately without gaps, and the thicknesses of both are made substantially equal. Both are polished to a predetermined thickness.

[For production]

According to the method for manufacturing an electrode substrate of the present invention, the protrusion of the transparent electrode is completely removed, and the transparent electrode and transparent insulating film on the substrate are formed in a substantially flat shape. Furthermore, the resistance value and patterning accuracy of the transparent electrode are maintained well.

〔Example〕

An embodiment of the method for manufacturing an electrode substrate according to the present invention is shown in FIG. In this example, first, aluminosilicate glass;
A glass substrate 1 made of NA40 (manufactured by HOYA ■) was prepared, and In203 powder mixed with 5 weight percent of 5002 was molded into a pellet (15φ x 15t) as the vapor deposition material, and the substrate temperature was 300°C and the degree of vacuum was 5 X
A transparent conductive film 12 (thickness: 3000 mm) is deposited on one main surface of the glass substrate 1 by vacuum evaporation under conditions of 10-6 TOrr (FIG. 1(a)). Next, a positive photoresist; HP-1350 (manufactured by Hoechst) is applied to the transparent conductive film 12 by a spinner method, and a resist film 13 (thickness: 5000) is deposited (FIG. 2(b)). This resist film 13 is dried at 90° C. for 30 minutes in an N2 gas atmosphere if necessary. Next, this resist film 13 is closely exposed to ultraviolet rays through an exposure mask, and then developed with a special developer to form a predetermined resist pattern 14 (FIG. 3(C)). Next, after baking the substrate 1 with the resist pattern 14 in an air oven at 120°C for 30 minutes, it was placed in a CCl4 gas atmosphere, at a partial pressure of 0.2 Torr, and at a high frequency power of 150 W (frequency 13.56 MHz).
Under these conditions, using the resist pattern 14 as a mask, the exposed portion of the transparent conductive film 12 is removed by plasma etching to form a transparent electrode pattern 15 under the resist pattern 14 (FIG. 4(d)). . Next, the resist pattern 14 on the transparent electrode pattern 15 is removed using a resist stripping agent (
In this example, it is removed by treatment with hot concentrated sulfuric acid (see figure (e)).

Next, under the conditions of A: a partial pressure of 3 x 10' TOrr in a gas atmosphere, a substrate temperature of 150°C, and a high-frequency cuff of 00 W (frequency 13.56) 1) 12), fused silica was used as a target by high-frequency sputtering. , Si 02
A transparent insulating film 11116 (thickness: 5000 Å) is deposited on one main surface of the substrate 1 with the transparent electrode pattern 15 (see ( )).Then, using an abrasive (e.g. Ce02), The previously formed transparent electrode pattern 15 is exposed on the surface of the insulating film 16, and the thickness of both films is set to a predetermined value (e.g.
2000) to form transparent electrode pattern 1.
8 and a transparent insulating film 11 are obtained (see (g) in the same figure).
)). Note that since the transparent electrode patterns 15 and 18 described above are formed by the plasma etching method, their side surfaces are formed approximately at right angles to the substrate 1, and the patterning accuracy can be improved.

The present invention is not limited to the materials and film formation methods used in the above examples. Regarding the transparent conductive film, the material is s
Instead of n 025% by weight - 1n20s 951iffi%, an appropriate composition ratio may be selected without being limited to this composition ratio, and Sn 02 may be used.

In2 03 , 5bz01 and Sn 02-3b2 0
3, In20l-3b203, etc. may be used, and the film forming method thereof is a sputtering method instead of a vacuum evaporation method.

Ion blating method, CVD method, etc. may also be used. The plasma pressure and the multiple values of high-frequency power for forming the transparent conductive film pattern are appropriately selected. Regarding the resist film, the material used is negative photoresist instead of positive resist.

Positive or negative electron beam resists, X-ray resists, etc. may be used, and the coating method may be a roll coater method, a spray method, etc. instead of the spinner method, and the film thickness may be You may select as appropriate. As for the transparent insulating film, instead of SiO2 as its material,
A12 03 , Ti 02 .

Ta2 os , Zr 02 , Y2 03
, Si3N4, etc. may be used, and instead of high frequency sputtering, direct current sputtering, vacuum evaporation, ion blating, etc. may be used as the film forming method.
CVD method etc. may be used, and the film thickness is 50%.
The number of people is not limited to 00, and it is sufficient if the thickness is equal to or greater than the thickness of the transparent electrode described above.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to manufacture an electrode substrate with a transparent electrode that has a flat surface without physical steps, and therefore it is possible to significantly improve the dielectric breakdown voltage of E1 display elements, etc. Since the effect of this step can be ignored, it is possible to make the film thickness of the transparent electrode even thicker compared to conventional products, which has a tremendous effect on increasing the size and resolution of EL display elements, etc. . Further, in the manufacturing process of the transparent electrode, there is no adverse effect on the resistance value at the time of formation of the transparent conductor rrs, so that the resistance value of the transparent electrode can be maintained at a good level.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view showing each step of the method for manufacturing an electrode substrate according to the present invention, Fig. 2 is a cross-sectional view showing the structure of a conventional electrode substrate, and Fig. 3 is an EL device using a conventional electrode substrate. A partially enlarged cross-sectional view of a display element and FIG. 4 are cross-sectional views showing examples of each step of a conventional method for manufacturing an electrode substrate. DESCRIPTION OF SYMBOLS 1... Substrate, 12... Transparent conductive film, 13... Resist film, 14... Resist pattern, 15. ia・
...Transparent electrode pattern, 16...Transparent insulating film, 17.
...Transparent insulating film pattern Figure 1 Figure 2 Figure 4 Procedure Correction! (Voluntary) April 1985
2nd day of the month

Claims (3)

[Claims] (1) Selectively patterning a transparent conductive film deposited on one main surface of the substrate to form a transparent electrode pattern, and embedding a transparent insulating film pattern in the exposed portion on the one main surface of the substrate. A method for producing a featured electrode substrate. (2) An electrode substrate according to claim 1, characterized in that patterns of transparent electrodes and transparent insulating films are arranged alternately without gaps, and the thicknesses of both films are substantially equal. Production method. (3) A method for manufacturing an electrode substrate according to claim 2, characterized in that each pattern of the transparent electrode and the transparent insulating film is polished to a predetermined thickness.