CN104498951A - Oxydol etching solution for copper-molybdenum alloy films - Google Patents

Abstract

The application discloses an etching solution for a hydrogen peroxide system copper-molybdenum alloy film. The etching solution of the present application does not contain fluoride, and the main components of the etching solution include 1-35% hydrogen peroxide, 0.05-5% inorganic acid, 0.1-5% hydrogen peroxide stable agent, 0.1-5% metal chelating agent, 0.1-5% etching additive, 0.1-5% surfactant and 0.1-5% defoamer, and the balance is deionized water. The etching solution of the present application is environmentally friendly and has no pollution, mild reaction and easy control, suitable etching cone angle after etching, small CD loss and good defoaming performance, which improves the overall performance of the etching solution and lays a foundation for high-precision processing.

Description

A kind of etching solution for hydrogen peroxide system copper-molybdenum alloy film

technical field

The present application relates to the field of etching solution, in particular to an etching solution for a hydrogen peroxide-based copper-molybdenum alloy film.

Background technique

Etching is a technology that removes materials using chemical reaction or physical impact; etching technology is divided into wet etching and dry etching. Among them, wet etching uses chemical reagents to achieve the purpose of etching through chemical reactions.

In recent years, while people's demand for liquid crystal displays has been increasing, higher requirements have been put forward for product quality and screen accuracy, and the effect of etching can directly lead to the quality of the circuit board manufacturing process, affecting the quality of high-density thin wires. Image precision and quality. Aluminum or aluminum alloys have been used for the metal wiring of conventional liquid crystal display devices. However, with the increase in size and resolution of liquid crystal displays, gate lines and data lines connected to thin film transistors will become longer. Resistance also increases, thus creating problems such as signal delay. Therefore, research has turned to materials with lower resistance, namely copper or wiring combinations with copper as the main component. Molybdenum has high adhesion to substrates such as glass, is difficult to diffuse into silicon semiconductor films, and has both barrier properties; therefore, a laminated film containing copper or a copper-molybdenum alloy mainly composed of copper is deposited by sputtering, etc. In the film-forming process, a film is formed on a substrate such as glass, and then an electrode pattern is formed through an etching process using a resist or the like as a mask.

In order to improve the etching speed of molybdenum alloy, fluoride is often added to the existing hydrogen peroxide-based etching solution for copper-molybdenum alloy. The disadvantages of the etchant adding fluoride are: first, fluoride is extremely unfriendly to the environment; second, it has strong corrosion ability, and it is often difficult to control the etching angle and etching time during the reagent etching process; third, due to its strong Corrosive, and more dangerous to operators and client equipment. At present, as more and more producers begin to use copper-molybdenum alloy films, the demand for etching solutions with processing precision is greatly increased. Therefore, there is an urgent need for an etching solution that is environmentally friendly, safe in production, high in processing accuracy, and easy to control. liquid.

Contents of the invention

The purpose of this application is to provide an improved hydrogen peroxide-based etching solution for copper-molybdenum alloy films.

In order to achieve the above object, the application adopts the following technical solutions:

The application discloses an etching solution for a hydrogen peroxide system copper-molybdenum alloy film. The etching solution of the application does not contain fluoride, and the main components of the etching solution include hydrogen peroxide, 0.05 -5% mineral acid, 0.1-5% hydrogen peroxide stabilizer, 0.1-5% metal chelating agent, 0.1-5% etching additive, 0.1-5% surfactant and 0.1-5% disinfectant Foaming agent, the balance is deionized water.

It should be noted that the etching solution of the present application uses an appropriate amount of inorganic acid instead of fluoride, and cooperates with surfactants, defoamers, etc., which not only avoids the pollution of fluoride to the environment, but also improves the etching performance; and, replacing The reaction of the final etching solution is relatively mild, the entire etching is easy to control, and it is also safer for operators and client equipment. Wherein, the inorganic acid mainly promotes the dissolution of copper oxidized by hydrogen peroxide; in the preferred version of the present application, the inorganic acid is selected from at least one of nitric acid, sulfuric acid, phosphoric acid, and boric acid.

Preferably, the amount of hydrogen peroxide is 5-35% of the total weight of the etching solution; more preferably, the amount of hydrogen peroxide is 10-30% of the total weight of the etching solution.

It should be noted that hydrogen peroxide is the main oxidant of the copper-molybdenum alloy. When the content of hydrogen peroxide is within the scope of this application, it can ensure that the etching is carried out effectively, and at the same time, the time rate can be controlled and maintained in an appropriate range, so that Control of the amount of etching also becomes easy.

Preferably, the amount of the inorganic acid is 0.05-3% of the total weight of the etching solution; the amount of the metal chelating agent is 0.1-3% of the total weight of the etching solution; the amount of the defoaming agent is 0.1-3% of the total weight of the etching solution.

In the present application, the effect of the hydrogen peroxide stabilizer is to stabilize hydrogen peroxide, therefore, as long as it is usually used as a hydrogen peroxide stabilizer; in the preferred version of the application, considering the overall performance of the etching solution, the The hydrogen peroxide stabilizer is selected from one or two of diethylaminepentaacetic acid, N-hydroxyethylethylenediaminetriacetic acid and polyacrylamine.

In the present application, the main function of the metal chelating agent is to form a chelate with the metal ions produced in the etching process to deactivate it, thereby inhibiting the decomposition reaction of hydrogen peroxide in the etching solution; preferably, the metal chelating agent is selected from At least one of ethylenediaminetetraacetic acid, aminotriacetic acid, diethylenetriaminepentaacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, gluconic acid, sodium tartrate, citric acid, and glycolic acid .

In the present application, the main function of the etching additive is in order to adjust the etching rate and prolong the service life of the etching solution. In the preferred scheme of the application, the etching additive is at least two of organic acids, nitrogen-containing heterocyclic compounds and salts; wherein , the organic acid is selected from at least one of acetic acid, phenol, o-cresol, m-cresol, p-cresol, butyric acid, valeric acid and glycine; the nitrogen-containing heterocyclic compound is selected from quinoline, 8-hydroxy At least one of quinoline, benzotriazole, hydroxymethylbenzotriazole, imidazole and benzimidazole; salts selected from at least one of tartrate, heptonate, sodium gluconate and sodium alginate kind.

In the present application, the main function of the surfactant is to effectively improve the wettability and permeability of the etching solution to the substrate, and at the same time, it is not easy to generate residues, and the sulfonic acid type substance is preferably used; Overall performance, preferably, the surfactant is selected from at least one of alkyl sulfonic acid, alkylbenzene sulfonic acid and sodium dioctyl succinate sulfonate.

In the present application, because the addition of the surfactant enhances the foamability of the etching solution, thereby hindering the contact between the substrate and the etching solution, causing poor etching accuracy, rough etching surface and other defects, therefore, the etching solution of the present application added Defoamer, preferably polyether defoamer; In the preferred version of the present application, considering the overall performance of the etching solution, preferably, the defoamer is selected from nonylphenol polyoxyethylene 5 ether, nonylphenol polyoxyethylene At least one of vinyl 10 ether, lauryl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, polyoxyethylene alkylphenol ether and polyoxyethylene fatty alcohol ether kind.

Owing to adopting above technical scheme, the beneficial effect of the present application is:

The etching solution of the present application does not add fluoride, and has no pollution to the environment; moreover, the reaction is mild and easy to control, the etching cone angle after etching is suitable, the CD loss is small, and the defoaming performance is good, which improves the overall performance of the etching solution and is high-precision Processing lays the foundation.

Detailed ways

With the widespread use of copper-molybdenum alloy films, the demand for an etching solution that can improve processing accuracy has greatly increased; and the existing etching solutions, as mentioned above, are not only environmentally unfriendly, but also difficult to control the etching, which cannot meet The demand for high-precision processing; therefore, this application has developed an ideal fluorine-free hydrogen peroxide-based copper-molybdenum alloy film etching solution, which can not only ensure good etching performance, but will not cause damage to glass substrates, silicon layers, etc. Corrosion, and does not contain fluoride, no pollution to the environment. It should be noted that fluoride mainly reacts with Mo, and the thickness of Mo in the copper-molybdenum system is relatively small, so although the etching solution of the present application does not contain fluoride, it has little influence on the etching rate; and , due to the combination of inorganic acid, hydrogen peroxide stabilizer, metal chelating agent, etching additive, surfactant and antifoaming agent, while ensuring the etching performance, its etching speed is also different from that of adding fluoride Not much.

The present application will be described in further detail below through specific examples. The following examples only further illustrate the present application, and should not be construed as limiting the present application.

Example

The etching solution in this example is composed of hydrogen peroxide, inorganic acid, hydrogen peroxide stabilizer, metal chelating agent, etching additive, surfactant, defoamer and deionized water. In this example, sulfuric acid is used as the inorganic acid; polyacrylic acid amine is used as the hydrogen peroxide stabilizer; glycolic acid is used as the metal chelating agent; and the etching additive is composed of nitrogen-containing heterocyclic compounds and salts. Specifically, imidazole is used for nitrogen-containing heterocyclic compounds. , the salt is sodium alginate; the surfactant is OT surfactant purchased from the market; the defoamer is NP-5 purchased from the market, that is, nonylphenol polyoxyethylene 5 ether. In this example, the dosages of the above components were tested respectively, and four comparative tests were set up, see Table 1 for details, and each percentage in Table 1 is a percentage by weight, that is, the percentage of the component in the total weight of the etching solution, and the balance for deionized water.

The consumption and comparative test of each component of table 1

Prepare the etching solution according to the dosage in Table 1, and test the defoaming property of the etching solution. Specifically, put 30mL of ketone etching solution in a 100mL test tube, shake vertically several times, and measure the foam height after stopping for 1 minute. The test results are shown in Table 2. It can be seen that the foam height of the test group and the contrast group added with defoamer NP-5 is controlled below 0.5 cm, while the contrast group 2 without NP-5 has a foam height of more than 1.0 cm. It shows that NP-5 can effectively play the role of defoaming; thereby reducing the impact of the foaming of the etching solution on the etching precision and etching quality.

The etching solution will be prepared according to the consumption in Table 1, and the copper-containing metal film and the molybdenum-containing metal film of electrodes such as TFT-LCD displays are etched. Specifically, a barrier film formed of molybdenum-based materials and a copper/molybdenum-based multilayer film formed of copper or a material mainly composed of copper are sequentially stacked on a glass substrate by sputtering, developed and exposed to form the expected Anti-corrosion coating pattern; the glass substrate is etched at 32°C with the etching solution of each group test or comparative test in Table 1 of this example, and the etching time is about 3 minutes. After the etching is completed, it is cleaned and dried in a conventional manner . And according to the conventional measurement method, its etching cone angle, residue, CD loss uniformity, etc. were tested. At the same time, the service life of the etching solution was measured according to the conventional method, and the test of the service life was expressed by the highest dissolved Cu content when the etching solution still maintained a good performance. All test results are shown in Table 2.

Table 2 etching solution and etching effect measurement results

As shown in the results in Table 2, (1) By comparing the test group 2 and the comparison group 4, it can be seen that the etching solution of this example, with or without adding fluoride, has little effect on the etching rate; however, after adding fluoride, the etching cone The angle is greatly improved. It can be seen that the etching solution without adding fluoride of the present application is easier to control the etching process and is more conducive to high-precision processing. (2) Due to the large amount of hydrogen peroxide used in test group 4, the etching taper and CD loss are too large; 1-35%, preferably 5-35%, and in order to ensure the etching effect, more preferably 10-30%. (3) According to the data of the comparison group 1 and the comparison group 3, the etching additive has a great influence on the service life and the etching rate of the etching solution, and must be used in conjunction with nitrogen-containing heterocyclic compounds and salts; in addition, because the test group 1 The amount of imidazole in the medium is low, which affects the service life; in addition, this example also uses organic acids to test, and the results show that at least two of organic acids, nitrogen-containing heterocyclic compounds and salts are used as etching additives at the same time. best effect. (4) For the residual problem, the effect of test group 2 and test group 4 is relatively good, but the amount of hydrogen peroxide in test group 4 is relatively large, and others affect the overall performance of the etching solution; test group 1 is due to the partial consumption of imidazole Low, the amount of imidazole in test group 3 is too large, which is not conducive to improving the overall performance of the etching solution, so there are residues; and the amount of hydrogen peroxide in test group 5 is relatively small, so residues are also produced. Therefore, hydrogen peroxide The optimal dosage is still 10-30%.

On the basis of test group 2, this example continues to test the etching solution components and the dosage of each component. The results show that in addition to sulfuric acid, the inorganic acid can also be replaced by nitric acid, phosphoric acid, boric acid, etc. The amount of inorganic acid is 0.05-5% of the total weight of the etching solution, and the optimal 0.05-3% has the best effect; peroxidation Hydrogen stabilizer can also use diethylamine pentaacetic acid and N-hydroxyethyl ethylenediamine triacetic acid except polyacrylic acid amine, the consumption of hydrogen peroxide stabilizer is preferably 0.1-5% of the total weight of etching solution; metal chelate The mixture can also use ethylenediaminetetraacetic acid, aminotriacetic acid, diethylenetriaminepentaacetic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, gluconic acid, sodium tartrate, citric acid, etc., metal The amount of chelating agent is 0.1-5% of the total weight of the etching solution, preferably 0.1-3%; for etching additives, in addition to sodium alginate, tartrate, heptose, gluconic acid can be used as salts Sodium replacement, nitrogen-containing heterocyclic compounds can be replaced by quinoline, 8-hydroxyquinoline, benzotriazole, hydroxymethylbenzotriazole, benzimidazole, etc., while organic acids can be replaced by acetic acid, phenol, o-methyl Phenol, m-cresol, p-cresol, butyric acid, valeric acid and glycine, etc., the total amount of etching additives is 0.1-5% of the weight of the etching solution, and the amount of nitrogen-containing heterocyclic compounds is greater than 0.01%, and Less than 3.5%, otherwise it will affect the overall performance of the etching solution; the surfactant can be sulfonic acid-type substances, such as alkylsulfonic acid, alkylbenzenesulfonic acid and sodium dioctyl succinic acid sulfonate, and the amount used is the weight of the etching solution 0.1-5%; the defoamer can also use nonylphenol polyoxyethylene 10 ether, lauryl alcohol polyoxyethylene ether, octylphenol polyoxyethylene 5 ether, octylphenol polyoxyethylene 5 ether, poly The amount of oxyethylene alkylphenol ether, polyoxyethylene fatty alcohol ether, etc. is also 0.1-5% by weight of the etching solution, preferably 0.1-3%.

The etching solution prepared according to the above dosage and composition has a suitable etching cone angle, small CD loss, improved performance of the etching solution, and can meet the requirements of high-precision processing.

The above content is a further detailed description of the present application in conjunction with specific implementation modes, and it cannot be considered that the specific implementation of the present application is limited to these descriptions. For those of ordinary skill in the technical field to which this application belongs, some simple deduction or substitutions can be made without departing from the concept of this application, which should be deemed to belong to the protection scope of this application.

Claims (10)

1. a dioxygen water system copper-molybdenum alloy film etching solution, it is characterized in that: not fluoride in described etching solution, and, the main component of etching solution comprises the hydrogen peroxide, the mineral acid of 0.05-5%, the stabilizer of hydrogen peroxide of 0.1-5%, the metal chelator of 0.1-5%, the etching additive of 0.1-5%, the tensio-active agent of 0.1-5% and the defoamer of 0.1-5% that account for etching solution gross weight 1-35%, and surplus is deionized water.

2. etching solution according to claim 1, is characterized in that: the consumption of described hydrogen peroxide is the 5-35% of etching solution gross weight.

3. etching solution according to claim 1, is characterized in that: the consumption of described hydrogen peroxide is the 10-30% of etching solution gross weight.

4. etching solution according to claim 1, is characterized in that: the consumption of described mineral acid is the 0.05-3% of etching solution gross weight; The consumption of described metal chelator is the 0.1-3% of etching solution gross weight; The consumption of described defoamer is the 0.1-3% of etching solution gross weight.

5. the etching solution according to any one of claim 1-4, is characterized in that: described mineral acid is selected from least one in nitric acid, sulfuric acid, phosphoric acid, boric acid.

6. the etching solution according to any one of claim 1-4, is characterized in that: described stabilizer of hydrogen peroxide is selected from one or both of diethylamine pentaacetic acid, N-hydroxyethyl-ethylenediamine nitrilotriacetic and poly amic acid.

7. the etching solution according to any one of claim 1-4, is characterized in that: described metal chelator is selected from least one of ethylenediamine tetraacetic acid (EDTA), nitrilotriacetic acid, diethylene triaminepentaacetic acid(DTPA), diethylene triamine pentacetic acid (DTPA), hydroxyethylethylene diamine tri-acetic acid, gluconic acid, sodium tartrate, citric acid and oxyacetic acid.

8. the etching solution according to any one of claim 1-4, is characterized in that: described etching additive is selected from least two kinds of organic acid, nitrogen-containing heterocycle compound and salt;

Described organic acid is selected from least one in acetic acid, phenol, ortho-methyl phenol, m-methyl phenol, p-methyl phenol, butyric acid, valeric acid and glycine;

Described nitrogen-containing heterocycle compound is selected from least one in quinoline, oxine, benzotriazole, methylol benzotriazole, imidazoles and benzoglyoxaline;

Described salt is selected from least one in tartrate, heptose hydrochlorate, Sunmorl N 60S and sodium alginate.

9. the etching solution according to any one of claim 1-4, is characterized in that: described tensio-active agent is selected from least one in alkylsulphonic acid, alkyl benzene sulphonate (ABS) and dioctyl succinate disulfonate acid.

10. the etching solution according to any one of claim 1-4, is characterized in that: described defoamer is selected from least one in Nonyl pheno 5 ether, Nonyl pheno 10 ether, Brij 35, octyl phenol polyoxyethylene 5 ether, octyl phenol polyoxyethylene 5 ether, polyxyethylated alkylphenol and polyoxyethylene aliphatic alcohol ether.