CN1308758C - Thin film transistor panel manufacturing method, etching tank cleaning method and use of strong alkali - Google Patents

Abstract

The present invention discloses a method for manufacturing a thin film transistor panel, a method for cleaning an etching tank, and the use of a strong alkali. First, a semiconductor structure to be etched is immersed in an oxalic acid solution in an etching tank for a period of time and then taken out. The semiconductor structure to be etched has at least an indium tin oxide (ITO) layer and a patterned photoresist layer located on the ITO layer. The oxalic acid solution is used to remove the exposed portion of the ITO layer to form a plurality of ITO electrodes. Then, the oxalic acid solution in the etching tank is discharged, and a strong alkali solution is used to clean the etching tank to remove the residue in the etching tank. In this way, it is possible to avoid the sensing element in the etching tank being accidentally touched by the residue and activating an error alarm, and prevent the TFT panel process from being interrupted, so as to improve the yield of the TFT panel.

Description

Thin film transistor panel manufacturing method, etching tank cleaning method and use of strong alkali

technical field

The present invention relates to a manufacturing method of a thin film transistor (thin film transistor, TFT) panel, and in particular to a thin film transistor panel comprising a step of cleaning an indium tin oxide (ITO) etching groove with a strong alkali solution manufacturing method.

Background technique

Liquid crystal displays (LCDs) are widely used due to their advantages of low radiation and small size. And thin film transistor (thin film transistor, TFT) LCD is very popular in high-end electronic products because of its characteristics of high brightness and large viewing angle.

A traditional TFT LCD consists of a TFT panel and a color filter panel. The CF panel includes at least a common electrode, a black matrix, and a color filter. The TFT panel includes at least a substrate ( substrate), multiple scan lines (scanlines), multiple data lines (data lines), multiple storage capacitors (storage capacitors), multiple TFTs and multiple pixel electrodes (pixel electrodes). The scan lines and the data lines define a plurality of pixels, and each pixel has a pixel area, and each pixel area has a TFT. In addition, the material of the pixel electrode is usually transparent indium tin oxide (ITO), so the pixel electrode may also be called an ITO electrode. The TFT LCD must use a plurality of spacers to open the TFT panel and the CF panel to adjust the thickness of the liquid crystal layer in the TFT LCD.

Please refer to FIGS. 1A-1D , which are cross-sectional views showing the flow of a conventional TFT panel manufacturing method. First, in FIG. 1A, a substrate 102 is provided, and several TFTs 104, several scanning lines and several data lines are formed on the substrate 102. Taking a single pixel as an example for illustration, the TFT 104 is formed on the substrate 102 and has a drain 104a. Then, a passivation layer 106 is formed on the substrate 102, the passivation layer 106 covers the TFT 104, and then, an organic layer 108 is formed on the passivation layer 106, as shown in FIG. 1B. In FIG. 1B , the passivation layer 106 and the organic layer 108 have a contact hole 110 through which the contact hole 110 is used to expose part of the drain electrode 104a. Then, an ITO layer 112 is formed on the organic layer 108 and on the drain electrode 104a in the contact hole 110, as shown in FIG. 1C. In FIG. 1C , a patterned photoresist layer 114 is formed on the ITO layer 112 , where the semiconductor structure 120 to be etched is completed. Then, the exposed portion of the ITO layer 112 is removed by wet etching to form the ITO electrode 112a, and the ITO electrode 112a is electrically connected to the drain electrode 104a through the contact hole 110 . Then, the patterned photoresist layer 114 is removed with a photoresist stripper, as shown in FIG. 1D , and the TFT panel 100 is finally completed.

Please refer to FIG. 2 , which shows a flow chart of a conventional wet etching method and a cleaning method for etching grooves. In Fig. 2, at first, in step 202, immerse semiconductor structure 120 to be etched in the ITO etchant in the ITO etching tank (etcher) for a period of time and then take it out, semiconductor structure 120 to be etched has at least ITO layer 112 and is positioned at ITO Patterned photoresist layer 114 on layer 112 . For example, the ITO etchant can be the oxalic acid solution (ITO06SD) produced by Taiwan Emerk Company, and the oxalic acid solution (ITO06SD) contains oxalic acid (oxalic acid) and surfactant (surfactant), and patterned photoresist The resist layer 114 is, for example, a PEP5 photoresist (AZ TFP-650F5) produced by Clariant, Japan. After soaking the semiconductor structure 120 to be etched in the oxalic acid solution (ITO06SD) for a period of time, the oxalic acid solution (ITO06SD) can remove the exposed part of the ITO layer 112 to form the ITO electrode 112a, but red residue will appear in the ITO etching tank (residue). Next, enter step 204 , drain the ITO etchant in the ITO etching tank, and at this time, there is still red residue in the etching tank. Then, in step 206, the operator must use a dust-free cloth to wipe the red residue in the ITO etching tank to clean the ITO etching tank.

It should be noted that the operator must carefully wipe the red residue in the ITO etching groove with a dust-free cloth to avoid damage to the sensing element in the ITO etching groove caused by improper wiping or excessive force. Therefore, the operator will not be able to completely remove the red residue in the ITO etching tank, and the red residue that has not been removed will accumulate in the ITO etching tank. When a large amount of semiconductor structures 120 to be etched are immersed in the ITO etching solution in the ITO etching tank, the content of the red residue accumulated in the ITO etching tank will be more and more, so that the sensing element in the ITO etching tank It is very easy to be mistakenly touched by the accumulated red residue and activate a false alarm, which greatly affects the yield of TFT panels.

Contents of the invention

In view of this, the purpose of the present invention is exactly to provide a kind of manufacturing method of thin film transistor (thin filmtransistor, TFT) panel, it cleans the design of etching groove with strong alkali solution, can effectively remove the residue in the etching groove, avoids etching The sensing element in the tank is falsely touched by the residue and activates the false alarm. And it can prevent the interruption of the TFT panel process, so as to improve the yield of the TFT panel.

According to the object of the present invention, a method for manufacturing a thin film transistor panel is provided. First, soak a semiconductor structure to be etched in an oxalic acid solution in an etching tank for a period of time and take it out. The semiconductor structure to be etched has at least an indium tin oxide (ITO) layer and a pattern on the ITO layer The photoresist layer is oxidized, and the oxalic acid solution is used to remove the exposed part of the ITO layer to form several ITO electrodes. Next, drain the oxalic acid solution in the etching tank, and use a strong alkali solution to clean the etching tank to remove the residue in the etching tank, wherein the weight percentage concentration of the strong alkali solution is 3wt%-10wt%.

According to still another object of the present invention, a kind of cleaning method of etching groove is proposed, is used on an etching groove, and an oxalic acid solution can be placed in the etching groove, and the oxalic acid solution can provide a pattern with an ITO layer and a position on the ITO layer. Dip the semiconductor structure to be etched into the photoresist layer. The oxalic acid solution will etch the exposed part of the ITO layer to form several ITO electrodes, and the etching tank is cleaned after the etched semiconductor to be etched and the oxalic acid solution are taken out. In the method, firstly, a strong alkali solution is used to clean the etching tank to remove residues in the etching tank, wherein the concentration of the strong alkali solution is 3wt%-10wt%. Next, use a deionized water to clean the etching tank.

According to another object of the present invention, a kind of purposes of strong alkali solution is proposed, and it is in order to clean an etching groove, and an oxalic acid solution can be placed in the etching groove, and this oxalic acid solution can provide one with an ITO layer and one on the ITO layer. The patterned photoresist layer semiconductor structure to be etched is immersed, and the oxalic acid solution will etch the exposed part of the ITO layer to form several ITO electrodes. After the etched semiconductor to be etched and the oxalic acid solution are taken out of the etching tank Cleaning is carried out, wherein the weight percentage concentration of the strong alkali solution is 3wt%-10wt%.

Description of drawings

In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and understandable, a preferred embodiment is specifically cited below, together with the accompanying drawings, and described in detail as follows, wherein:

1A to 1D show a cross-sectional view of the process of a traditional thin film transistor (TFT) panel manufacturing method;

Fig. 2 shows the flow chart of the cleaning method of traditional wet etching method and etching tank;

FIG. 3 shows a flowchart of a method for manufacturing a thin film transistor panel according to a preferred embodiment of the present invention;

Fig. 4 shows the Fourier Transform Infrared Spectroscopy (FTIR) analysis experiment result of red residue in the etching groove;

Fig. 5 shows photoresist soaked in the FTIR analysis experiment result in the oxalic acid solution;

Fig. 6 shows the FTIR analysis result of in-situ ITO groove (tank) extract, and its mixing with photoresist;

Figure 7 shows the comparison of the FTIR analysis results of the extract component analysis in the oxalic acid solution (ITO06SD and ITO05N).

The reference signs in the accompanying drawings are explained as follows:

100: thin film transistor (TFT) panel

102: Substrate 104: Thin Film Transistor

106: Protective layer 108: Organic layer

110: Contact hole 112: Indium tin oxide (ITO) layer

112a: Indium tin oxide electrode

114: Patterned photoresist layer

120: semiconductor structure to be etched

Detailed ways

Please refer to FIG. 3 , which shows a flowchart of a method for manufacturing a thin film transistor (thin film transistor, TFT) panel according to a preferred embodiment of the present invention. In FIG. 3 , firstly, in step 302 , a substrate is provided. Next, enter step 304 , form several TFTs on the substrate, and each TFT has a drain. Then, in step 306 , a protective layer is formed on the substrate, and the protective layer covers the TFTs. Next, enter step 308 , form an organic layer on the protection layer, and the organic layer and the protection layer have a plurality of contact holes passing through, and each contact hole is used to expose a part of the drain of each TFT. Then, enter step 310, form an indium tin oxide (indium tin oxide, ITO) layer on the organic layer and the drain electrodes in each contact hole. Next, in step 312 , a patterned photoresist layer is formed on the ITO layer, and a semiconductor structure to be etched is completed here. For example, the patterned photoresist layer can be a PEP5 photoresist (AZ TFP-650F5) produced by Clariant, Japan.

Then, enter step 314 , soak a semiconductor structure to be etched in an oxalic acid solution in an etching tank for a period of time and take it out. For example, the oxalic acid solution may be an oxalic acid solution (ITO06SD) produced by Taiwan Emerk Company, and the oxalic acid solution (ITO06SD) includes oxalic acid and a surfactant. For example, oxalic acid solution (ITO06SD) is used to remove the exposed part of the ITO layer to form several ITO electrodes, and red residue will appear in the etching groove. In addition, when the semiconductor structure to be etched is etched and taken out, the patterned photoresist layer can be removed to form a TFT panel. Then, enter step 316 , drain the oxalic acid solution in the etching tank, and use a strong alkali solution to clean the etching tank to remove and dissolve the red residue. Then, enter step 318 , use a deionized water to clean the etching tank, so as to achieve the purpose of cleaning the etching tank. Wherein, step 316 and step 318 can be regarded as a cleaning method of the etching groove.

As for why the present invention chooses strong alkali solution to remove the red residue in the etching tank, its basis reason is explained as follows:

(1) Analysis experiment of red residue: the present invention utilizes Fourier transform infrared spectrometer (fourier transform infrared, FTIR) to analyze red residue, as a result, it is found that red residue contains at least seven different mixtures, as shown in Figure 4.

(2) Experiment of photoresist immersed in oxalic acid solution: the results of FTIR analysis show that the red residue contains photoresist components, as shown in Figure 5, it is inferred that the patterned photoresist layer is in oxalic acid The solution was slightly dissolved when etching the ITO layer.

(3) The extract analysis experiment of the oxalic acid solution after the etched ITO layer in the etching tank: the FTIR analysis results show that the extract composition of the oxalic acid solution is similar to the red residue, as shown in Figure 6, it is inferred that the red residue is It is formed by the reaction of oxalic acid solution and photoresist. Among them, the oxalic acid solution (ITO05N) was the control group.

(4) Composition analysis experiment of the surfactant in the oxalic acid solution: FTIR analysis results show that the surfactant in the oxalic acid solution is similar to the red residue, as shown in FIG. 7 .

(5) Dissolution experiment of photoresist with different concentrations of oxalic acid solution: As the concentration of oxalic acid solution increases, the dissolution rate of photoresist also increases.

(6) Comparative experiment of photoresist dissolved in deionized water, oxalic acid solution (comprising oxalic acid and surfactant) and pure oxalic acid: the order of dissolution of photoresist is pure oxalic acid>oxalic acid solution (comprising oxalic acid and surfactants) > deionized water. Therefore, the cause of the leaching of the photoresist from the oxalic acid solution is mainly the oxalic acid in the oxalic acid solution, not the surfactant in the oxalic acid solution.

The present invention uses acetone (acetone), n-butyl alcohol (n-butyl alcohol, NBA), propylene glycol monomethyl ether acetate (propylene glycol monomethyl ether acetate, PGMEA), photoresist stripper (stripper), alcohol, iso Propanol (isopropyl alcohol, IPA), nitric acid solution, surfactant and deionized water were used to dissolve the red residue. The experimental results are shown in the following table: Solvent name Solubility of red residue acetone completely dissolved NBA completely dissolved PGMEA completely dissolved Photoresist Stripper completely dissolved Alcohol Slightly soluble IPA Slightly soluble nitric acid Insoluble Surfactant Insoluble Deionized water Insoluble

It can be seen from the above table that the red residue can be completely dissolved in acetone, NBA, PGMEA and photoresist stripper, while the red residue is slightly soluble in alcohol and IPA, but the red residue is insoluble in nitric acid, surface Active agent and deionized water. Therefore, the red residue can only be dissolved in organic solvents. Since the etching tank is made of organic materials, in order to avoid damage to the etching tank, another inorganic solvent is selected in the present invention, that is, a strong alkali solution.

In the experiment of dissolving red residue in strong alkali solution, the present invention takes sodium hydroxide solution as an example for illustration, and its experimental steps are as follows:

(1) Prepare sodium hydroxide solutions of different weight percentage concentrations (wt%), such as 3wt%, 6wt% and 10wt% sodium hydroxide solutions.

(2) Take out the red residue in the etching tank, divide and weigh and record.

(3) 50 milliliters of 3wt%, 6wt% and 10wt% sodium hydroxide solutions were each reacted with the red residue.

(4) The temperature was maintained at 30° C. and stirred for 10 minutes.

(5) Filter and weigh the net weight of the remaining red residue.

(6) Calculate the dissolution rate of the red residue, the results are shown in the table below: Sodium hydroxide solution (wt%) Original weight of red residue before dissolution (g) Net weight of dissolved red residue (g) Dissolution rate (%) Solubility (visual method) 3 0.0018 0.0008 55.6 There is residue 6 0.0023 0.0000 100 completely dissolved 10 0.0018 0.0001 94.4 completely dissolved

It can be known from the above table that the red residue can be completely dissolved in 3wt%-10wt% sodium hydroxide solution. That is to say, the red residue can be completely dissolved in a 3wt%-10wt% strong alkali solution, which is the basis for selecting the strong alkali solution in the present invention.

The manufacturing method of the thin film transistor panel disclosed in the above-mentioned embodiments of the present invention is designed to clean the ITO etching groove with a strong alkali solution, which can effectively remove the residues in the ITO etching groove and prevent the sensing element in the etching groove from being contaminated by residues. A false alarm is triggered by a false touch. And prevent the interruption of the TFT panel process, so as to improve the yield of the TFT panel.

In summary, although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Those skilled in the art can make various changes without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the appended claims.

Claims (10)

1. the manufacture method of a thin-film transistor display panel comprises at least:

Soaking one treats also to take out after a period of time in the oxalic acid solution of etching semiconductor structures in an etching bath, wherein this treats that etching semiconductor structures has an indium tin oxide layer and at least and is positioned at patterning photoresist layer on this indium tin oxide layer, this oxalic acid solution is in order to remove this indium tin oxide layer of part, to form a plurality of indium-tin oxide electrodes; And

Discharge the oxalic acid solution in this etching bath, and use a strong base solution to clean this etching bath, to remove the residue in this etching bath, wherein the weight percent concentration of this strong base solution is 3wt%～10wt%.

2. the method for claim 1, wherein this strong base solution is a sodium hydroxide solution.

3. the method for claim 1, the oxalic acid solution of this method in this discharges this etching bath wherein, and use a strong base solution to clean this etching bath, also to comprise after the step of removing the residue in this etching bath:

Use this etching bath of a washed with de-ionized water.

4. the method for claim 1, wherein this method also comprises before step in the oxalic acid solution of etching semiconductor structures in an etching bath is treated in this immersion one:

One substrate is provided;

Form a plurality of thin film transistor (TFT)s on this substrate, and respectively this thin film transistor (TFT) has a drain electrode;

Form a protective seam on this substrate, and cover those thin film transistor (TFT)s;

Form an organic layer on this protective seam, this organic layer and this protective seam have a plurality of contact holes of perforation, and respectively this contact hole is in order to expose the respectively drain electrode of the part of this thin film transistor (TFT);

Form indium tin oxide layer in this organic layer and respectively in the drain electrode in this contact hole; And

Form a patterning photoresist layer on this indium tin oxide layer.

5. the clean method of an etching bath, be used for an etching bath, this etching bath can be inserted an oxalic acid solution, but the etching semiconductor structures for the treatment of that this oxalic acid solution sacrificial vessel has indium tin oxide layer and is positioned at patterning photoresist layer on this indium tin oxide layer immerses, this oxalic acid solution is with the indium tin oxide layer of etching institute exposed portions, to form a plurality of indium-tin oxide electrodes, this etching bath is cleaned after etching semiconductor and this oxalic acid solution are removed in treating after the etching, and this clean method comprises:

Use a strong base solution to clean this etching bath, to remove the residue in this etching bath, wherein the weight percent concentration of this strong base solution is 3wt%～10wt%; And

Use this etching bath of a washed with de-ionized water.

6. method as claimed in claim 5, wherein this strong base solution is a sodium hydroxide solution.

7. method as claimed in claim 5, wherein this treats that etching semiconductor structures also comprises:

One substrate;

A plurality of thin film transistor (TFT)s, it is formed on this substrate, and respectively this thin film transistor (TFT) has a drain electrode;

One protective seam is formed on this substrate, and covers those thin film transistor (TFT)s;

One organic layer; be formed on this protective seam, this organic layer and this protective seam have a plurality of contact holes of perforation, and respectively this contact hole is in order to expose the respectively drain electrode of the part of this thin film transistor (TFT); wherein, have this indium tin oxide layer and this patterning photoresist layer on this organic layer.

8. the purposes of a strong base solution, it is in order to clean an etching bath, this etching bath can be inserted an oxalic acid solution, but the etching semiconductor structures for the treatment of that this oxalic acid solution sacrificial vessel has indium tin oxide layer and is positioned at patterning photoresist layer on this indium tin oxide layer immerses, this oxalic acid solution is with the indium tin oxide layer of etching institute exposed portions, to form a plurality of indium-tin oxide electrodes, this etching bath is cleaned after etching semiconductor and this oxalic acid solution are removed in treating after the etching, and wherein the weight percent concentration of this strong base solution is 3wt%～10wt%.

9. the purposes of highly basic as claimed in claim 8, wherein this strong base solution is a sodium hydroxide solution.

10. the purposes of highly basic as claimed in claim 8, wherein this treats that etching semiconductor structures also comprises:

One substrate;

A plurality of thin film transistor (TFT)s are formed on this substrate, and respectively this thin film transistor (TFT) has a drain electrode;

One protective seam is formed on this substrate, and covers those thin film transistor (TFT)s; And

One organic layer; be formed on this protective seam; this organic layer and this protective seam have a plurality of contact holes of perforation, and respectively this contact hole wherein has this indium tin oxide layer and this patterning photoresist layer in order to expose the respectively drain electrode of the part of this thin film transistor (TFT) on this organic layer.

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