JP2002141329A - Etching liquid concentration controlling device and device and method for manufacturing liquid crystal display, and liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control the concentration of etching liquid for stabilizing the composition of the chemical. SOLUTION: The etching liquid concentration controlling device is provided with a wet etching means 11 for fine processing of a transparent electrode of indium oxide and tin oxide by etching liquid; a concentration measuring means 12 for automatically measuring the concentration of the etching liquid of the wet etching means 11; a controlling means which compares the measurement results information and a set concentration range of etching conditions, calculates the amount of ingredients to be added according to the difference, and controls the liquid to a necessary ion concentration and an adding means 14 which supplies specified ingredients to be replenished by a concentration control command signal from the controlling means 13. In this way, the concentration of the etching liquid is automatically measured and can be controlled by automatically adding the ingredients to be replenished by processing of the results by electronic signal in such a way that the ingredients are contained in the etching liquid within a set concentration range. Accordingly, the chemical composition can be controlled and stabilized within a set range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an etchant concentration control device, a device and a method for manufacturing a liquid crystal display device, and a liquid crystal display device.

[0002]

2. Description of the Related Art A transparent electrode (ITO) made of indium oxide and tin oxide formed on one main surface of a glass plate as a substrate, and more specifically, a transparent electrode used for a liquid crystal display (LCD) array substrate and the like. (IT
When microfabricating O), it is required to control the transparent electrode (ITO) composed of indium oxide and tin oxide without generating etching residues.

A conventional method for patterning a transparent electrode (ITO) made of indium oxide and tin oxide using oxalic acid is disclosed in, for example, Japanese Patent Application Laid-Open No. 7-141932. Hereinafter, a conventional wet etching method for etching a transparent electrode (ITO) made of indium oxide and tin oxide with oxalic acid will be described.

FIG. 3 is a sectional view showing the conventional etching process for each process. In FIG. 3A, for example, a glass substrate is used as a substrate, and a transparent electrode film (ITO) 2 made of indium oxide and tin oxide is formed on the glass substrate 1.
Is deposited over the entire surface at a substrate temperature of room temperature and a film thickness of 75 nm.
As a deposition method, a sputtering method, an electron beam evaporation method, or the like is used. Then, a desired resist pattern 3 is formed on the transparent electrode film (ITO) 2 by using a usual photolithography method. At this time, the post-baking temperature of the photoresist greatly affects the etching shape, but the post-baking is performed at, for example, 135 ° C.

Then, as shown in FIG. 3B, oxalic acid having a concentration of 3.4% by weight and 0.1% by weight of a concentration were used as an etching solution.
, And a transparent electrode film (IT
O) is patterned. As an etching apparatus, a batch immersion type, a single wafer spray type, or the like is used. 75n
The etching of the transparent electrode film (ITO) having a thickness of m proceeds uniformly in the vertical and horizontal directions, which is a feature of wet etching. The etching end time during this period is about 90 seconds and 3
An overetching time of 3% was applied to perform etching for 120 seconds.

Finally, when the photoresist is removed, FIG.
As shown in (C), a transparent electrode (ITO) pattern 4 having a taper angle of about 70 degrees was formed.

[0007]

However, in the above-described wet etching system, the concentration of the etchant changes. This concentration change is larger in the single wafer spray type etching apparatus, which has become the mainstream of wet etching in recent years with the enlargement of the glass substrate than in the conventional batch immersion type etching apparatus, and the change in the chemical composition of the etching solution is large. There is a problem that the life of the chemical solution is significantly shortened.

[0008] This change in the chemical composition causes oxalic acid to crystallize due to evaporation of pure water in the etching solution and remains on the substrate surface as a residue during etching, causing a patterning failure of the ITO. I needed to.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide an etchant concentration control apparatus capable of controlling the concentration of an etchant to stabilize a chemical composition and prolong the life of the chemical solution, an apparatus and a method for manufacturing a liquid crystal display, and a method of manufacturing the same. It is to provide a liquid crystal display device.

[0010]

According to a first aspect of the present invention, there is provided an etching solution concentration control apparatus for finely processing a transparent electrode made of indium oxide and tin oxide with an etching solution. And a concentration measuring means for automatically measuring the concentration of the etching solution of the wet etching means, and comparing the measurement result information with a set concentration range of the etching condition, and determining the addition amount of the replenishment component of the etching solution based on the difference. Control means for calculating and controlling to a required ion concentration, and adding means for supplying a predetermined replenishing component to the etching solution of the wet etching means in accordance with a concentration control command signal from the control means are provided.

As described above, the concentration measuring means for automatically measuring the concentration of the etching solution in the wet etching means, the measurement result information is compared with the set concentration range of the etching conditions, and the replenishment component of the etching solution is determined based on the difference. A control means for calculating the amount of addition of the liquid and controlling it to the required ion concentration; and an addition means for supplying a predetermined replenishing component to the etching liquid of the wet etching means by a concentration control command signal from the control means. Automatically measure the concentration of
The result is processed by an electric signal to automatically add a replenishing component so that each component of the etching solution falls within the set concentration range, thereby controlling the etching solution concentration, and controlling and stabilizing the chemical solution composition within a predetermined range. be able to.

According to a second aspect of the present invention, in the first aspect, the control means is a computer, and has a recording medium on which information of etching conditions is recorded. As described above, since the control means is a computer and has a recording medium on which information of the etching condition is recorded, the measurement result information of the etching solution can be compared with the set concentration range of the etching condition.

According to a third aspect of the present invention, in the first or second aspect, the adding means automatically adds pure water to the wet etching means according to a concentration control command signal from the control means. As described above, since the adding means automatically adds the pure water to the wet etching means according to the concentration control command signal from the control means, it is suitable for stabilizing the composition of the etching solution.

According to a fourth aspect of the present invention, in the first or second aspect, the etchant is a mixture of oxalic acid and a surfactant. As described above, the etching solution is a mixed solution of oxalic acid and a surfactant, and can pattern the transparent electrode.

According to a fifth aspect of the present invention, in the etching solution concentration control apparatus, the ratio of the mixed solution is 1 to 16 oxalic acid.
% By weight, and 0 to 1% by weight of a surfactant. in this way,
The ratio of the mixture is 1 to 16% by weight of oxalic acid,
It is preferable that the content be 1% by weight for patterning the transparent electrode film.

In a sixth aspect of the present invention, the concentration measuring means is an ion chromatograph. Thus, since the concentration measuring means is an ion chromatograph, it can be suitably implemented as an apparatus for measuring the concentration of oxalic acid and a surfactant.

According to a seventh aspect of the present invention, there is provided an apparatus for manufacturing a liquid crystal display device, comprising the etchant concentration control apparatus according to the first, second, third, fourth, fifth or sixth aspect. Thus, claim 1,
Since the apparatus has the etchant concentration control device described in 2, 3, 4, 5, or 6, the above effects can be obtained in the production of the liquid crystal display device.

According to a eighth aspect of the present invention, in the method of manufacturing a liquid crystal display device, a wet etching step of finely processing the transparent electrode with an etchant when etching the transparent electrode made of indium oxide and tin oxide used for the liquid crystal display array substrate. And a concentration measurement step of automatically measuring the concentration of the etching solution, and comparing the measurement result information with the set concentration range of the etching condition, calculating the amount of the replenishment component of the etching solution based on the difference, and calculating the required ion concentration. And an addition step of supplying a predetermined replenishing component to the etching solution in accordance with the concentration control command signal from the control step.

As described above, when a transparent electrode made of indium oxide and tin oxide used for a liquid crystal display array substrate is etched, a wet etching step of finely processing the transparent electrode with an etchant and automatically measuring the concentration of the etchant A concentration measurement step to be performed, a control step of comparing the measurement result information with a set concentration range of etching conditions, calculating an addition amount of a replenishment component of the etching solution based on the difference, and controlling to a required ion concentration; and And an addition step of supplying a predetermined replenishing component to the etching solution according to a concentration control command signal from the semiconductor device. It is possible to control the concentration of the etchant by automatically adding a replenishing component so that the component enters.
The chemical composition can be controlled and stabilized within a predetermined range.

According to a ninth aspect of the present invention, in the method for manufacturing a liquid crystal display device according to the eighth aspect, the etching solution is a mixed solution of oxalic acid and a surfactant, and the etching solution after controlling the concentration of the oxalic acid is 1 to 16 oxalic acids. % By weight, and 0 to 1% by weight of a surfactant.

As described above, the etching solution is a mixture of oxalic acid and a surfactant, and the etching solution after controlling the concentration of the etching solution is 1 to 16% by weight of oxalic acid and 0 to 1% by weight of the surfactant. In addition, it is possible to maintain the state of the etching solution optimal for patterning the transparent electrode film.

According to a tenth aspect of the present invention, a liquid crystal display device is formed by using the method for manufacturing a liquid crystal display device according to the eighth or ninth aspect. As described above, since the liquid crystal display device is formed by using the method for manufacturing a liquid crystal display device according to the eighth or ninth aspect, the patterning of the transparent electrode is improved, and the quality can be improved.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a configuration diagram of an etchant concentration control system according to an embodiment of the present invention.

In FIG. 1, reference numeral 11 denotes wet etching means for finely processing a transparent electrode (ITO) made of indium oxide and tin oxide with an etchant, and 12 denotes a concentration measuring means for automatically measuring the concentration of the etchant in the wet etching means 11. , 13 are control means for comparing the measurement result information with the set concentration range of the etching condition, calculating the addition amount of the replenishment component of the etching solution based on the difference, and controlling to the required ion concentration. This is an adding means for supplying a predetermined replenishing component to the etching solution of the wet etching means 11 in accordance with the concentration control command signal.

In this case, the wet etching means 11 is a single wafer spray type etching apparatus. Concentration measuring means 1
2 is an ion chromatograph. The control unit 13 converts the measurement result of the ion chromatograph 12 into an electric signal, transmits the signal to a computer, compares the result with a set concentration range, converts the difference into an electric signal, and calculates an etching solution addition amount from a required ion concentration. It is. This control device 13
Has a recording medium on which information of etching conditions is recorded. The adding means 14 is an adding device capable of automatically adding a replenishing component required to be added to the etching tank 11 a of the etching device 11 by an electric signal from the control device 13.

The operation of a manufacturing apparatus and a manufacturing method for manufacturing a liquid crystal display device using the etching solution concentration control system of the present embodiment configured as described above will be described below.

When etching a transparent electrode made of indium oxide and tin oxide used for a liquid crystal display array substrate of a liquid crystal display device, a wet etching step of finely processing the transparent electrode with an etchant, and automatically measuring the concentration of the etchant A concentration measurement step to be performed, a control step of comparing the measurement result information with a set concentration range of etching conditions, calculating an addition amount of a replenishment component of the etching solution based on the difference, and controlling to a required ion concentration; and And supplying a predetermined replenishing component to the etching solution in response to a concentration control command signal from the controller.

The etching solution is a mixed solution of oxalic acid and a surfactant, and the ratio thereof is 1 to 16% by weight of oxalic acid and 0 to 1% by weight of the surfactant. In this case, the concentration is 3.4% by weight.
Of oxalic acid and 0.1% by weight of a surfactant. Using this etching solution, a transparent electrode (ITO) made of indium oxide and tin oxide was patterned at 45 ° C. by using the conventional wet etching method shown in FIG. The ion chromatograph 12 took in the etching solution in-line from the etching tank 11a of the etching apparatus 11, and measured the concentrations of oxalic acid and the surfactant at an arbitrarily set measurement interval. In this embodiment, the measurement interval is set every hour.

The control device 13 includes the ion chromatograph 1
The measurement result from No. 2 was converted into an electric signal, transmitted to a computer, compared with a set concentration range, the difference was converted into an electric signal, and the amount of pure water added was calculated from the required ion concentration. The etching liquid adding device 14 supplied a required amount of pure water into the etching tank 11 a of the etching device 11 based on the calculation result from the control device 13. In this embodiment, the addition interval is set every hour. Further, the etching solution after controlling the concentration of the etching solution is adjusted to be 1 to 16% by weight of oxalic acid and 0 to 1% by weight of a surfactant.

FIG. 2 is a graph showing the change before and after the liquid exchange of the etching solution of this embodiment and the conventional example. FIG. 2 (A) shows a change in oxalic acid concentration, and FIG. 2 (B) shows a change in surfactant concentration. In this embodiment (the present embodiment), the oxalic acid concentration and the surfactant concentration are slightly constant after the liquid exchange, but are approximately constant. However, in the conventional example, the oxalic acid concentration increases with the lapse of days after the liquid exchange. Further, it can be seen that the rate of increase in the surfactant concentration is large.

Further, in the liquid crystal display device formed by using the above-mentioned manufacturing method, the patterning of the transparent electrode becomes good, and the quality can be improved.

As described above, according to this embodiment, the ion chromatograph 12 capable of automatically measuring the concentration of the etching solution is provided to the wet etching apparatus 11 for finely processing a transparent electrode (ITO) made of indium oxide and tin oxide. And a control device 13 capable of converting the measurement result into an electric signal, transmitting the result to a computer, comparing the difference with a set concentration range, converting the difference into an electric signal, and calculating the addition amount of the supplementary component from the required ion concentration; By providing an addition device 14 for supplying a predetermined replenishment component to the etching device,
The chemical composition can be stabilized by controlling the concentration of the etchant by adding a required amount of pure water to the change in the liquid composition of the single wafer spray type etching apparatus 11. Further, when the measurement result of the ion chromatograph 12 exceeds a predetermined concentration range of the etching solution, pure water can be supplied to the etching tank 11a at an arbitrary addition interval at an arbitrary settable addition amount.

Although the concentration measuring device 12 is an ion chromatograph in this embodiment, it may be a concentration measuring device using an absorbance method or a neutralization titration method. Further, pure water is added to the adding device 14, but a separate liquid adding device of oxalic acid and the additive, or a mixed solution of oxalic acid and the additive may be used.

[0034]

According to the first aspect of the present invention, there is provided an etching solution concentration control apparatus comprising: a concentration measuring means for automatically measuring the concentration of an etching solution in a wet etching means; information on the measurement result and a set concentration range of etching conditions; Control means for calculating the amount of replenishment component added to the etchant based on the difference and controlling the required ion concentration, and a predetermined replenishment component is added to the etchant of the wet etching means by a concentration control command signal from the control means. Supply means, the concentration of the etchant is automatically measured, and the result is automatically added to the etchant by electric signal processing so that each component of the etchant falls within the set concentration range. The concentration can be controlled, and the chemical composition can be controlled and stabilized within a predetermined range. For this reason, it is possible to extend the life of the chemical solution replacement, and its practical effect is great.

According to the second aspect, since the control means is a computer and has a recording medium on which information of the etching condition is recorded, the measurement result information of the etching solution can be compared with the set concentration range of the etching condition.

According to the third aspect, since the adding means automatically adds pure water to the wet etching means in response to a concentration control command signal from the control means, it is suitable for stabilizing the composition of the etching solution.

In the fourth aspect, the etching solution is a mixture of oxalic acid and a surfactant, and can pattern the transparent electrode.

According to the fifth aspect, the ratio of the mixed solution is 1 to oxalic acid.
It is preferable to use 16% by weight and 0 to 1% by weight of a surfactant in patterning the transparent electrode film.

According to the sixth aspect, since the concentration measuring means is an ion chromatograph, it can be suitably implemented as an apparatus for measuring the concentration of oxalic acid and a surfactant.

According to the apparatus for manufacturing a liquid crystal display device according to claim 7 of the present invention, claim 1, 2, 3, 4, 5, or 6 is provided.
Since the above-described etching solution concentration control device is provided, the above effects can be obtained in the manufacture of a liquid crystal display device.

According to the method of manufacturing a liquid crystal display device of the present invention, when the transparent electrode made of indium oxide and tin oxide used for the liquid crystal display array substrate is etched, the transparent electrode is finely etched with an etching solution. The wet etching process for processing, the concentration measuring process for automatically measuring the concentration of the etching solution, and comparing the measurement result information with the set concentration range of the etching conditions, and determining the amount of the replenishment component of the etching solution based on the difference. It includes a control step of calculating and controlling to a required ion concentration and an addition step of supplying a predetermined replenishing component to the etching liquid by a concentration control command signal from the control step, so that the concentration of the etching liquid is automatically measured, and the result is obtained. Replenishment components are automatically added so that each component of the etching solution enters within the set concentration range by electrical signal processing, and etching is performed. It is possible to control the concentration, it can be stabilized by controlling the chemical composition within the predetermined range. For this reason, it is possible to prolong the replacement time of the chemical solution, and its practical effect is great.

In the ninth aspect, the etchant is a mixture of oxalic acid and a surfactant, and the etchant after controlling the concentration of the etchant is 1 to 16% by weight of oxalic acid and 0 to 1 of the surfactant.
Since the weight% is used, the state of the etching solution optimal for patterning the transparent electrode film can be maintained.

According to the liquid crystal display device according to the tenth aspect of the present invention, since the liquid crystal display device is formed by using the method of manufacturing the liquid crystal display device according to the eighth or ninth aspect, the patterning of the transparent electrode becomes good, and the quality is improved. Can be planned.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an etchant concentration control system according to an embodiment of the present invention.

FIG. 2A is a graph showing a change in oxalic acid concentration of an etching solution according to an embodiment of the present invention and a conventional example, and FIG. 2B is a graph showing a surfactant concentration change in the etching solution.

FIG. 3 is a cross-sectional view showing each step of a conventional wet etching process.

[Explanation of symbols]

 11 Single wafer spray type etching apparatus 12 Ion chromatograph 13 Control unit 14 Addition unit

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H01L 21/306 FF Term (Reference) 2H088 FA11 FA20 FA25 FA30 HA02 KA09 MA16 MA20 2H092 HA04 KB14 MA18 MA35 MA59 4K057 WA11 WB20 WE14 WE30 WG03 WM03 WN02 5F043 AA26 BB28 DD13 EE07 EE23 EE29 GG04 5G435 AA17 KK05 KK09 KK10

Claims (10)

[Claims] 1. A wet etching means for finely processing a transparent electrode made of indium oxide and tin oxide with an etching liquid, a concentration measuring means for automatically measuring the concentration of the etching liquid in the wet etching means, information on the measurement result and etching. Control means for comparing the set concentration range of the conditions and calculating the addition amount of the replenishment component of the etching solution based on the difference, and controlling the required ion concentration; and a predetermined replenishment component by a concentration control command signal from the control means. And an adding means for supplying the etching solution to the etching solution of the wet etching means. 2. The etching liquid concentration control device according to claim 1, wherein the control means is a computer, and has a recording medium on which information of the etching condition is recorded. 3. The etching liquid concentration control apparatus according to claim 1, wherein the adding means automatically adds pure water to the wet etching means in response to a concentration control command signal from the control means. 4. The etching liquid concentration control device according to claim 1, wherein the etching liquid is a mixed liquid of oxalic acid and a surfactant. 5. A mixture comprising 1 to 16% by weight of oxalic acid,
The etching solution concentration control device according to claim 4, wherein the content of the surfactant is 0 to 1% by weight. 6. The etching solution concentration control device according to claim 1, wherein the concentration measuring means is an ion chromatograph. 7. An apparatus for manufacturing a liquid crystal display device having the etchant concentration control device according to claim 1, 2, 3, 4, 5, or 6. 8. A wet etching process for finely processing a transparent electrode made of indium oxide and tin oxide used for a liquid crystal display array substrate with an etchant, and a concentration for automatically measuring the concentration of the etchant. The measurement step, a control step of comparing the measurement result information and the set concentration range of the etching conditions, calculating the addition amount of the replenishment component of the etching solution based on the difference, and controlling the required ion concentration, and And supplying an etching solution with a predetermined replenishing component in response to the concentration control command signal. 9. The etching solution is a mixed solution of oxalic acid and a surfactant, and the etching solution after controlling the concentration of the etching solution is 1 to 16% by weight of oxalic acid and 0 to 1% by weight of a surfactant. The manufacturing method of the liquid crystal display device according to the above. 10. A liquid crystal display device formed by using the method for manufacturing a liquid crystal display device according to claim 8.