One-dosage type copper-molybdenum display etching solution and preparation method and application thereof

Abstract

The invention relates to a one-dosage type copper-molybdenum display etching solution and a preparation method and application thereof. The etching liquid comprises the following components in parts by weight: 5-15 parts of hydrogen peroxide; 10 to 15 parts of organic acid; 8-12 parts of an organic base; 0.008 to 0.07 part of a chelating agent; 0.002 to 0.07 part of a corrosion inhibitor; 0.04 to 0.3 part of a surfactant; 0.1 to 0.6 part of a hydrogen peroxide stabilizer; and 65-73 parts of ultrapure water. The chelating agent and the corrosion inhibitor in the etching solution are jointly adsorbed on the metal surface, the corrosion inhibitor and the chelating agent can form intermolecular hydrogen bonds to obtain a product with larger molecular volume, the product is adsorbed on the metal surface to generate a protective isolation layer, and meanwhile, the contained delocalized large pi bonds and nitrogen atoms can provide electron pairs for empty orbits of metal, so that the metal surface is protected. And coordination bonds are formed to be adsorbed on the metal surface to form a compact adsorption film, so that the corrosion of the metal is effectively inhibited, and the taper angle and the etching morphology of the etched metal are stabilized.

Description

Technical Field

[0001] The invention belongs to the field of etching solutions, and in particular relates to a one-dose copper-molybdenum display etching solution and a preparation method and application thereof. Background Art

[0002] With the development of science and technology, people's demand for liquid crystal displays is increasing, and at the same time, they have higher requirements for the quality and resolution of displays. In order to meet these needs, aluminum and copper are usually selected as the materials of display devices. Since copper has lower resistivity and higher conductivity than aluminum, it gradually replaces aluminum as the main material of display devices.

[0003] The poor adhesion between copper metal and glass and other substrates will cause the wiring material to separate and affect the product quality. Therefore, titanium metal, molybdenum metal, niobium metal, etc., which have good adhesion to glass and other substrates, are usually introduced as barrier films to enhance the adhesion between copper metal and glass and other substrates. Therefore, when making such copper process products, it is necessary to etch the copper layer and the barrier film layer at the same time.

[0004] In order to increase the etching rate of the etching solution, copper-molybdenum display etching solutions often add fluorine-containing and phosphorus-containing compounds. Fluorine-containing compounds are not only harmful to the environment and operators to a great extent, but also their strong corrosive ability will cause the glass components to be corroded and the etching angle to be uncontrolled. In addition, the addition of phosphorus-containing compounds will also rapidly increase the etching rate, and the etching morphology is difficult to control. Summary of the invention

[0005] The technical problems solved by the present invention are as follows: copper-molybdenum display etching solutions containing fluorine and phosphorus compounds have strong corrosion ability, uncontrolled etching angles, fast etching rates, and difficult to control etching morphology.

[0006] In view of the technical problems existing in the prior art, the present invention designs a one-dose copper-molybdenum display etching solution and its preparation method and application. The etching solution of the present invention does not contain fluorine and phosphorus compounds, is friendly to the environment and operators, and is also convenient for controlling the morphology and cone angle of the substrate after etching.

[0007] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising" and similar meanings, and closed-ended "consisting of..." and similar meanings.

[0008] In order to solve the above-mentioned technical problems, the present invention adopts the following solutions:

[0009] A one-dose copper-molybdenum display etching solution, characterized in that it comprises the following components, calculated by weight:

[0010]

[0011] Furthermore, the chelating agent is an aminosulfonic acid substance.

[0012] Furthermore, the chelating agent is one or more of L-cysteine ​​sulfinic acid, 4-aminobenzenesulfinic acid (CAS: 7472-15-3), p-acetamidobenzenesulfinic acid, hydroxyethylpiperazine ethanesulfonic acid, and aminosulfonic acid.

[0013] Furthermore, the corrosion inhibitor is 2,4,5-triamino-6-hydroxypyrimidine sulfate (CAS: 35011-47-3) and / or 4,5-diamino-6-hydroxypyrimidine hemisulfate (CAS: 102783-18-6).

[0014] Furthermore, the organic acid is at least two of citric acid, malic acid, succinic acid, malonic acid, salicylic acid, quinic acid, benzoic acid, ascorbic acid, and ethylenediaminetetraacetic acid.

[0015] Furthermore, the organic acid includes citric acid and succinic acid.

[0016] Furthermore, the mass ratio of citric acid to succinic acid is 20:1-40:1.

[0017] Furthermore, the organic base is one or more of ethanolamine, diethanolamine, triethanolamine, isobutanolamine and isopropanolamine.

[0018] Furthermore, the surfactant is sodium dioctyl sulfosuccinate and / or octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

[0019] Furthermore, the hydrogen peroxide stabilizer is phenylurea and / or diphenylaminourea.

[0020] Furthermore, in the present invention, the ultrapure water used is deionized water with a resistance of ≥18M.

[0021] The present invention also discloses a method for preparing the above-mentioned copper-molybdenum display etching solution, which is characterized by comprising the following steps:

[0022] Step 1: Weigh each component in its respective amount;

[0023] Step 2: Mix organic acid, corrosion inhibitor, hydrogen peroxide stabilizer (H 2 O 2 stabilizer), chelating agent and ultrapure water are stirred at room temperature until all materials are completely dissolved;

[0024] Step 3: Add a surfactant and an organic base to the mixed solution obtained in step 2, and stir at room temperature. At this time, there is an acid-base reaction, the solution releases heat, and the temperature will rise. When the solution temperature returns to room temperature, add hydrogen peroxide and stir at room temperature until all materials are evenly mixed.

[0025] The invention also discloses a use of the above-mentioned one-dosage type copper-molybdenum display etching solution in etching of liquid crystal display devices.

[0026] The present invention also discloses an etching method of the above-mentioned copper-molybdenum display etching solution, which is characterized by comprising the following steps:

[0027] Step 1: dissolving copper powder in the copper-molybdenum display etching solution of the first dosage form, and controlling the initial dissolved copper amount to 500ppm;

[0028] Step 2: Place the copper-molybdenum metal substrate into the copper-molybdenum display etching solution for etching, and keep the etching solution temperature at 30-40°C.

[0029] In the present invention, in order to further optimize the effect of the etching solution, the various components can be optimized: 8-12 parts of hydrogen peroxide; 12-15 parts of organic acid; 10-12 parts of organic base; 0.01-0.025 parts of chelating agent; 0.005-0.03 parts of corrosion inhibitor; 0.1-0.25 parts of surfactant; 0.3-0.5 parts of hydrogen peroxide stabilizer.

[0030] In the present invention, the chelating agent is preferably L-cysteine ​​sulfinic acid.

[0031] In the present invention, the corrosion inhibitor is preferably 2,4,5-triamino-6-hydroxypyrimidine sulfate.

[0032] In the present invention, the mass ratio of citric acid to succinic acid is preferably 30:1.

[0033] In the present invention, the surfactant is preferably octadecyl dimethyl hydroxyethyl quaternary ammonium nitrate.

[0034] In the present invention, the hydrogen peroxide stabilizer is preferably phenyl urea.

[0035] In the present invention, hydrogen peroxide is used as an oxidant to oxidize metallic copper and molybdenum into copper oxide and molybdenum oxide.

[0036] In the present invention, the chelating agent forms corresponding coordination products with metal ions through sulfonic acid group / sulfinic acid group to chelate metal ions, stabilize the state of metal ions in the solution, and does not undergo oxidation reaction or catalyze the decomposition of hydrogen peroxide, thereby extending the life of the etching solution.

[0037] In the present invention, the corrosion inhibitor can work synergistically with the chelating agent and be adsorbed on the metal surface together. Specifically, the corrosion inhibitor and the chelating agent can form intermolecular hydrogen bonds to obtain a product with a larger molecular volume, which produces a protective isolation layer by adsorbing on the metal surface. At the same time, the delocalized large π bonds and nitrogen atoms contained in the corrosion inhibitor can provide electron pairs for the empty orbits of the metal, and form a dense adsorption film by forming coordination bonds to adsorb on the metal surface, thereby alleviating the etching rate of metal copper and stabilizing the cone angle and morphology of the metal after etching.

[0038] In the present invention, the organic acid provides H + It is used to dissolve copper oxide and molybdenum oxide, and play the role of chelating metal ions, alleviating H 2 O 2 Decomposes and adheres to the metal surface to prevent excessive corrosion of the metal.

[0039] In the present invention, the organic base can also chelate metal ions and stabilize H 2 O 2 decomposition.

[0040] In the present invention, the surfactant can reduce the interfacial tension and enhance the adhesion rate of the etching solution.

[0041] In the present invention, the hydrogen peroxide stabilizer is used to reduce H 2 O 2 The decomposition rate is reduced and the life of the etching solution is extended.

[0042] In the present invention, the copper metal layer has a thickness of The thickness of the molybdenum metal layer is

[0043] The present invention provides a copper-molybdenum display etching solution and a preparation method and application thereof, which have the following beneficial effects:

[0044] 1. The present invention adopts a combination of aminosulfonic acid chelating agents and hydroxypyrimidine sulfate corrosion inhibitors, which are adsorbed on the metal surface together. The corrosion inhibitor and the chelating agent can form intermolecular hydrogen bonds to obtain a product with a larger molecular volume, which is adsorbed on the metal surface to produce a protective isolation layer. At the same time, the delocalized large π bonds and nitrogen atoms contained can provide electron pairs for the empty orbits of the metal, and are adsorbed on the metal surface by forming coordination bonds to form a dense adsorption film, which effectively inhibits copper corrosion and stabilizes the cone angle and etching morphology of the metal after etching.

[0045] 2. The present invention adopts aminosulfonic acid chelating agent, which has strong acidity and can react with metal copper and molybdenum oxides to produce metal ions. On the one hand, it can accelerate the dissolution of the metal and improve the etching rate. On the other hand, the amino group contained can also chelate the metal ions and reduce the decomposition rate of hydrogen peroxide. Therefore, the etching solution of the present invention can still maintain a stable etching rate without adding any fluorine-containing and phosphorus-containing substances. The etching rate is controllable, and a good etching morphology with an etching cone angle of 35-45° and a CD Loss of 0.7-1.0μm is obtained, so that it can load a copper ion concentration of 500-8000ppm.

[0046] Therefore, the one-dose copper-molybdenum etching solution of the present invention has very good application prospects and large-scale industrial promotion potential in the field of etching copper-molybdenum metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 : A microscope cross-sectional picture of the copper-molybdenum film layer after being etched by the copper-molybdenum display etching solution of Example 1, magnified 40,000 times;

[0048] Figure 2 : A microscope overhead view of the copper-molybdenum film layer after being etched by the copper-molybdenum display etching solution of Example 1, magnified 40,000 times;

[0049] Figure 3 : This is a microscope cross-sectional picture of the copper-molybdenum film layer after etching using the copper-molybdenum display etching solution of Comparative Example 1, magnified 40,000 times. DETAILED DESCRIPTION

[0050] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings:

[0051] Table 1 Example 1-Example 8

[0052]

[0053]

[0054]

[0055] Table 2 Comparative Examples 1-5

[0056]

[0057] Table 3 Test data

[0058] Taper angle (°) Single-side CD Loss(μm) Example 1 37-42 0.78-0.88 Example 2 35-42 0.83-1.00 Example 3 40-45 0.70-0.85 Example 4 38-44 0.71-0.87 Example 5 37-45 0.71-0.84 Example 6 39-45 0.75-0.86 Example 7 38-44 0.75-0.88 Example 8 38-44 0.85-0.97 Comparative Example 1 31-41 1.08-1.25 Comparative Example 2 30-42 1.10-1.28 Comparative Example 3 33-42 0.95-1.10 Comparative Example 4 25-38 1.11-1.37 Comparative Example 5 29-40 1.07-1.29

[0059] About the preparation method of the etching solution of the present invention:

[0060] The present invention relates to the preparation of multiple groups of etching solutions, and the preparation methods thereof are all prepared by referring to the following method:

[0061] Step 1: Weigh each component in its respective amount;

[0062] Step 2: Mix organic acid, corrosion inhibitor, H 2 O 2 Add stabilizer, chelating agent and ultrapure water into the container and stir at room temperature for 1 hour until all materials are completely dissolved;

[0063] Step 3: Add a surfactant and an organic base to the mixed solution obtained in step 2, and stir at room temperature for 1 hour. At this time, there is an acid-base reaction, the solution releases heat, and the temperature will rise. After the solution temperature returns to room temperature, add hydrogen peroxide and stir at room temperature for 1 hour until all materials are evenly mixed.

[0064] About etching method:

[0065] Step 1: dissolving copper powder in the copper-molybdenum metal etching solution of the first dosage form, and controlling the initial dissolved copper amount to 500ppm;

[0066] Step 2: Place the copper-molybdenum metal substrate into the copper-molybdenum metal etching solution for etching, and the etching reaction temperature is controlled between 30-40°C.

[0067] About performance testing and description:

[0068] Performance 1 Etching rate test method is:

[0069] Step 1: Place the pure copper sheet and the pure molybdenum sheet in the pre-treated etching solution with a copper dissolving amount of 500ppm, and observe the Just Etch Time (JET) of the substrate;

[0070] Step 2: The ratio of the film thickness of the etched pure copper sheet and pure molybdenum sheet substrate to the JET time is the etching rate of metal copper and molybdenum.

[0071] Performance 2Taper angle and CD Loss test method is:

[0072] Step 1: Evenly mix the copper-molybdenum metal etching solution and the copper powder to obtain the copper-molybdenum metal etching solution, wherein the copper content in the copper-molybdenum display etching solution is 500ppm, and the etching reaction temperature is controlled at 32°C to complete the pretreatment of the copper-molybdenum display etching solution;

[0073] Step 2: Place the copper-molybdenum glass substrate into the copper-molybdenum metal etching solution prepared in step 1 above to obtain a glass substrate with an ideal etching morphology;

[0074] Step 3: Dissolve 500 ppm of copper powder every 30 minutes, gradually increase the amount of dissolved copper in the etching solution, and continue to etch the glass substrate. When it is observed that hydrogen peroxide decomposes violently and generates many bubbles, stop etching. The amount of dissolved copper at this time is the life of the etching solution.

[0075] The taper angle and CD Loss of the etched glass substrate were tested by SEM. The test results are shown in Table 3 and Figure 1-3 .

[0076] If the pattern taper angle (taper angle) is too small, the CD loss is too large, which can easily lead to the collapse of the photoresist layer and affect the subsequent performance; if the pattern taper angle (taper angle) is too large, the CD loss is small, and there is a risk of metal residue. If the taper angle is too large or too small, cracks caused by poor step coverage will occur during subsequent film evaporation, or subsequent film evaporation will become difficult, so it is important to maintain an appropriate taper angle. Therefore, in order to ensure product performance and meet process requirements, the pattern taper angle is required to be stable within the range of 35°-45°, and the single-sided CD Loss is required to be stable within the range of 0.7-1.0μm.

[0077] Analysis of the test results:

[0078] In Comparative Example 1, due to the lack of the addition of the chelating agent L-cysteine ​​sulfinic acid, the metal copper ions and molybdenum ions cannot be well chelated, and most of them exist in a free state, which accelerates the decomposition of hydrogen peroxide, and a large amount of free metal ions also accelerates the dissolution of metal oxides, so that the etching rate is accelerated, resulting in a small etching cone angle, a large CD Loss, and a short life of the etching solution, which is only 6000ppm of copper dissolution.

[0079] In Comparative Example 2, due to the lack of the addition of the corrosion inhibitor 2,4,5-triamino-6-hydroxypyrimidine sulfate, the metal etching rate is too fast, the obtained etching cone angle is too small, the CD Loss is large, and it is easy to cause the collapse of the photoresist, affecting the subsequent performance.

[0080] In Comparative Example 3, the chelating agent is replaced with iminodiacetic acid. Since the acidity of the acetic acid group does not have a sulfonic acid group / sulfinic acid group, the iminodiacetic acid is partially ionized in the etching solution, reacts with the chelating agent, and is adsorbed on the metal surface to produce a protective isolation layer. However, the protective substance produced is not as much as in the embodiment, so the etching rate of the etching solution is faster, and the obtained etching cone angle and CD Loss are slightly larger.

[0081] In Comparative Example 4, the corrosion inhibitor was replaced with a strong inorganic acid, fluoroboric acid, which could quickly dissolve copper-molybdenum metal oxides into metal ions, and the etching rate was significantly increased, resulting in a larger etching cone angle and CD Loss. At the same time, the addition of inorganic acid also led to H2 O 2 The decomposition rate is accelerated, and the life of the etching solution is shortened, with a copper dissolution capacity of only 5000ppm.

[0082] In Comparative Example 5, the fluorine-containing substance ammonium fluoride is added. The addition of fluoride ions accelerates the etching of the metal. At the same time, the addition of ammonium ions can provide empty orbitals of nitrogen atoms to chelate free metal ions. The two groups act simultaneously to make the metal etched quickly and chelated quickly. Although the life of the etching solution is not significantly reduced, the etching cone angle is reduced.

[0083] The etching solution in the embodiment of the present invention has the ability to accelerate metal etching and can chelate metal ions well. The corrosion inhibitor and the chelating agent can form a dense protective film to alleviate the etching of the metal, thereby obtaining a good etching morphology and a specific etching cone angle, and having a good etching effect.

[0084] Further comparison is made through the attached drawings in the specification:

[0085] Figure 1 This is a microscope cross-sectional picture of the copper-molybdenum film layer after being etched by the copper-molybdenum display etching solution of Example 1, magnified 40,000 times. Figure 1 It can be seen that the copper-molybdenum etching solution of Example 1 can etch at a service life of 500-8000ppm of dissolved copper, and its pattern cone angle can be stabilized in the range of 37°-42°, and the single-sided CD Loss is stabilized in the range of 0.78-0.88μm.

[0086] Figure 2 This is a microscope overhead picture of the copper-molybdenum film layer after being etched by the copper-molybdenum display etching solution of Example 1, magnified 40,000 times. Figure 2 It can be seen that there is no metal layer residue, tailing or undercutting after etching the substrate.

[0087] Figure 3 This is a microscope cross-sectional picture of the copper-molybdenum film layer after etching with the copper-molybdenum display etching solution of Comparative Example 1, magnified 40,000 times. Figure 3 It can be seen that the copper-molybdenum etching solution of Comparative Example 1 can etch at a service life of 500-6000ppm of dissolved copper, and its etching rate is fast, and the pattern cone angle is in the range of 31°-41°, but the unilateral CD Loss far exceeds the required development specifications, in the range of 1.08-1.25μm. The larger CD Loss easily causes the photoresist to collapse, seriously affecting the use of the device.

[0088] The etching solution of the present invention adopts a combination of a sulfonic acid chelating agent and an aminohydroxypyrimidine sulfate corrosion inhibitor to be adsorbed on the metal surface together. The corrosion inhibitor and the chelating agent can form intermolecular hydrogen bonds to obtain a product with a larger molecular volume, which is adsorbed on the metal surface to generate a protective isolation layer. At the same time, the delocalized large π bonds and nitrogen atoms contained in the etching solution can provide electron pairs for the empty orbits of the metal, and are adsorbed on the metal surface by forming coordination bonds to form a dense adsorption film, which effectively inhibits copper corrosion and stabilizes the cone angle and etching morphology of the metal after etching.

[0089] The present invention is described exemplarily above in conjunction with the embodiments and drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned methods. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A one-dose copper-molybdenum display etching solution, characterized in that: Calculated by weight, it includes the following components:

2. The one-dose copper-molybdenum display etching solution according to claim 1, characterized in that: The chelating agent is aminosulfonic acid substance.

3. The copper-molybdenum display etching solution according to claim 1 or 2, characterized in that: The chelating agent is one or more of L-cysteine ​​sulfinic acid, 4-aminobenzenesulfinic acid, p-acetylaminobenzenesulfinic acid, hydroxyethylpiperazine ethanesulfonic acid and aminosulfonic acid.

4. The one-dose copper-molybdenum display etching solution according to claim 1, characterized in that: The corrosion inhibitor is 2,4,5-triamino-6-hydroxypyrimidine sulfate and / or 4,5-diamino-6-hydroxypyrimidine hemisulfate.

5. The one-dosage copper-molybdenum display etching solution according to claim 1, characterized in that: The organic acid is at least two of citric acid, malic acid, succinic acid, malonic acid, salicylic acid, quinic acid, benzoic acid, ascorbic acid and ethylenediaminetetraacetic acid.

6. The one-dose copper-molybdenum display etching solution according to claim 5, characterized in that: The organic acid includes citric acid and succinic acid.

7. The one-dose copper-molybdenum display etching solution according to claim 1, characterized in that: The organic base is one or more of ethanolamine, diethanolamine, triethanolamine, isobutanolamine and isopropanolamine.

8. A method for preparing a copper-molybdenum display etching solution according to any one of claims 1 to 7, characterized in that The following steps are involved: Step 1: Weigh the respective amounts of each component; Step 2: Stir the organic acid, corrosion inhibitor, hydrogen peroxide stabilizer, chelating agent and ultrapure water at room temperature until all materials are completely dissolved; Step 3: Add a surfactant and an organic base to the mixed solution obtained in step 2 and stir at room temperature. At this time, there is an acid-base reaction, the solution releases heat, and the temperature will rise. When the solution temperature returns to room temperature, add hydrogen peroxide and stir at room temperature until all materials are mixed evenly.

9. An etching method for a copper-molybdenum display etching solution according to any one of claims 1 to 7, characterized in that The following steps are involved: Step 1: dissolving copper powder in the one-dose copper-molybdenum display etching solution; Step 2: Place the copper-molybdenum metal substrate into the copper-molybdenum display etching solution obtained in step 1 for etching, and keep the etching solution temperature at 30-40°C.

10. Use of the single-dose copper-molybdenum display etching solution according to any one of claims 1 to 7 in etching liquid crystal display devices.

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