CN115011963A

CN115011963A - Copper metal etching liquid composition and use method thereof

Info

Publication number: CN115011963A
Application number: CN202210511182.3A
Authority: CN
Inventors: 徐帅; 李闯; 张红伟; 黄海东; 胡天齐; 王毅明
Original assignee: Jiangsu Heda Electronic Technology Co ltd
Current assignee: Jiangsu Heda Electronic Technology Co ltd
Priority date: 2022-05-11
Filing date: 2022-05-11
Publication date: 2022-09-06

Abstract

The invention discloses a copper metal etching solution composition and a using method thereof, relating to the field of etching solutions. The copper metal etching solution comprises a main agent and an auxiliary agent, wherein the main agent comprises the following preparation raw materials: the preparation raw materials of the auxiliary agent comprise the fluoride ion source, an acidic substance, the amino compound, the stabilizer, the heterocyclic compound and the ultrapure water, when in use, the main agent is contacted with the copper-containing metal layer, and then the auxiliary agent in the copper metal etching solution composition is supplemented, so that the preparation method has an extremely small CD-Loss value, can completely meet the production of small-size ultra-fine products, has an extremely high service life, has a copper ion concentration of over 14000ppm, effectively reduces the using amount of the etching solution, saves the cost, has a back taper angle of between 45 and 55 degrees, can not cause the defects of subsequent film layer broken lines and the like, has extremely low corrosion degree on glass, can be reworked and reused, saves the substrate, and has strong etching stability.

Description

Copper metal etching liquid composition and use method thereof

Technical Field

The invention relates to the field of etching solutions, C23F1/14, in particular to a copper metal etching solution composition and a using method thereof.

Background

The etching solution is a raw material for engraving the copper plate painting, and is mainly used for selectively removing copper, titanium and alloy in the circuit preparation process of various electronic element substrates and precision parts such as printed circuit boards, lead frames, ball grid arrays, carrier tape automatic bonding and array substrates according to requirements. Therefore, an etching solution with excellent performance should have a small bond size Loss (CD-Loss), a large time coefficient, a small side etching, a stable etching performance, an excellent copper dissolution capacity, and an easy wastewater treatment. In the prior art, the service life of the copper-titanium etching solution is 8000-10000ppm, and the copper load is lower; the corrosion of the substrate is easy to occur, and the glass substrate cannot be reworked; the CD-Loss is large, and the requirement of high-precision products cannot be met; the taper angle is more than 60 degrees, which easily causes the metal wire breakage of the subsequent film layer and further influences the final product performance.

Patent CN201710271534.1 discloses an etching solution composition, an array substrate for display device and a manufacturing method thereof, which comprises hydrogen peroxide, fluorine-containing compound, azole compound, glycine, sulfamic acid and polyol surfactant, and reduces the variation of cone angle and undercut caused during etching, thereby greatly increasing the number of processed substrates, but the etching solution can process 8000ppm at most and has short service life. Patent CN202011552376.5 discloses a copper etching solution composition and a preparation method and application thereof, wherein melamine or derivatives thereof with specific structures are added into a main agent and an auxiliary agent, and under the action of hydrogen peroxide, organic acid, organic base and a stabilizer, the surface of a copper/molybdenum film layer obtained after treatment has no residue, no chamfer and no crack, but the copper/molybdenum film layer has poor corrosion resistance on a glass substrate, low copper loading capacity and bond size loss can be further improved, and the requirement of high-precision products cannot be met.

Disclosure of Invention

In order to solve the above problems, the first aspect of the present invention provides a copper metal etchant composition, which is prepared from the following raw materials: a main agent and an auxiliary agent;

the preparation raw materials of the main agent comprise: peroxide, fluoride ion source, acidic substance, amino compound, stabilizer, heterocyclic compound and ultrapure water.

Preferably, the preparation raw materials of the main agent comprise, by mass: 1 to 20% of peroxide, 0.01 to 1% of fluoride ion source, 1 to 15% of acidic substance, 0.1 to 15% of amino compound, 0.01 to 1% of stabilizer, 0.01 to 1% of heterocyclic compound and the balance of ultrapure water.

Further preferably, the preparation raw materials of the main agent comprise, by mass: 6-10% of peroxide, 0.01-0.2% of fluoride ion source, 2-8% of acidic substance, 0.5-5% of amino compound, 0.1-0.5% of stabilizer, 0.02-0.5% of heterocyclic compound and the balance of ultrapure water.

In some preferred embodiments, the peroxide is selected from at least one of hydrogen peroxide, potassium peroxide, peracetic acid, magnesium peroxide, sodium percarbonate; preferably, the peroxide is hydrogen peroxide.

In some preferred embodiments, the fluoride ion source is selected from at least one of sodium fluoride, hydrofluoric acid, ammonium fluoride, ammonium bifluoride, potassium fluoride, ammonium fluoroborate, trifluoroacetic acid; preferably, the fluoride ion source is hydrofluoric acid.

The fluorine ion source is added into the system, so that the removal capability of the etching solution to the molybdenum niobium or molybdenum metal film layer can be improved and effectively enhanced, and the CD-Loss is reduced. The applicant has found that when the fluoride ion source is hydrofluoric acid, the surface residual amount of titanium ions can be further increased. Presumably, in the etching process, hydrofluoric acid can be adsorbed on the titanium surface in preference to oxygen atoms, and the formation of a dense and stable thin film protective film on the titanium surface is blocked, and the reaction with titanium ions is prevented to form soluble substances, so that the residual amounts of titanium content and other metal content on the substrate surface can be effectively reduced, and the substrate surface treated by the etching solution has no metal residue. The applicant unexpectedly finds that when the dosage of the fluoride ion source is 0.01-1%, the fluoride ion source can accelerate the etching rate of the etching solution, reduce the side etching, effectively inhibit the problem of interface cracks on the surfaces of different etched substrates, simultaneously cannot corrode glass substrates, and increases the application range of the etching solution under the synergistic action of substances such as peroxide, acidic substances, heterocyclic compounds and the like in a system.

In some preferred embodiments, the acidic substance is selected from at least one of magnesium salts of fatty acids, glycolic acid, diethylenetriamine pentamethylenephosphonic acid, sulfamic acid, N-hydroxyethylethylenediamine triacetic acid, diethylenetriamine pentaacetic acid, tartaric acid; preferably, the acidic substance is sulfamic acid.

In some preferred embodiments, the amino compound is selected from at least one of ethylenediamine, diethanolamine, diethylaminopropylamine, dimethylethanolamine, propylenediamine, tetramethylammonium oxide, triethanolamine, isopropanolamine, dimethylethylenediamine, tris (hydroxymethyl) aminomethane; preferably, the amino compound is tetramethylammonium oxide.

In some preferred embodiments, the stabilizer is selected from at least one of hydroxyethylidene diphosphonic acid, phenylcarbonyldiamide, p-aminophenylcarbonyldiamide, polyacrylamide, sodium p-hydroxybenzenesulfonate, p-aminophenylcarbonyldiamide, p-hydroxybenzenesulfonic acid, dipicolinic acid; preferably, the stabilizer is selected from at least one of phenyl carbonyl diamide and p-hydroxybenzene sulfonic acid; further preferably, the stabilizer is phenyl carbonyl diamide.

The addition of the stabilizer, especially when the stabilizer is phenylcarbonyldiamide, can cooperate with an acidic substance in a system to provide a proper acidic environment, inhibit the reaction activity of hydrogen peroxide in an alkaline environment, and simultaneously perform a metal complexing action with copper ions generated in the system, so that the rapid decomposition rate of the copper ions is reduced, and the service life of the etching solution is prolonged.

In some preferred embodiments, the heterocyclic compound is selected from at least one of 2-mercaptobenzothiazole, mercaptobenzotriazole, methylbenzotriazole, 3-aminotriazole, 5-aminotetrazole, 6-nitrobenzimidazole, 2-aminothiazole, 3-amino-1, 2, 4-triazole; preferably, the heterocyclic compound is selected from at least one of 3-amino triazole and 5-amino tetrazole; further preferably, the heterocyclic compound is 5-aminotetrazole.

The preparation method of the main agent comprises the step of mixing the preparation raw materials of the main agent.

The preparation raw materials of the adjuvant comprise: fluoride ion source, acidic material, amino compound, stabilizer, heterocyclic compound and ultrapure water.

Preferably, the auxiliary agent comprises the following components in percentage by mass: 0.01 to 1% of a fluoride ion source, 10 to 20% of an acidic substance, 1 to 10% of an amino compound, 0.01 to 2% of a stabilizer, 0.01 to 5% of a heterocyclic compound, and 0.01 to 1% of ultrapure water.

Further preferably, the auxiliary agent comprises, by mass percent: 0.01 to 0.5% of a fluoride ion source, 12 to 17% of an acidic substance, 5 to 8% of an amino compound, 0.05 to 1% of a stabilizer, 0.05 to 2% of a heterocyclic compound, and 0.03 to 0.5% of ultrapure water.

In some preferred embodiments, the heterocyclic compound is selected from at least one of 2-mercaptobenzothiazole, mercaptobenzotriazole, methylbenzotriazole, 3-aminotriazole, 5-aminotriazole, 6-nitrobenzimidazole, 2-aminothiazole, 4-aminotriazole, 3-amino-1, 2, 4-triazole; preferably, the heterocyclic compound is selected from at least one of 3-amino triazole, 4-amino tetrazole and 5-amino tetrazole; further preferably, the heterocyclic compound is 5-aminotetrazole.

The preparation method of the adjuvant comprises the step of mixing the preparation raw materials of the adjuvant.

In a second aspect of the present invention, a method for using a copper metal etchant composition is provided, wherein a main agent in the copper metal etchant composition is contacted with a copper-containing metal layer, and then an auxiliary agent in the copper metal etchant composition is supplemented.

Compared with the prior art, the invention has the following beneficial effects:

(1) in the application, the addition of the peroxide, the fluoride ion source, the sulfamic acid, the amino compound, the stabilizer and the heterocyclic compound enables the prepared etching solution to have a very small CD-Loss value, and can completely meet the production of small-size ultrahigh-precision products.

(2) The etching solution has extremely long service life, the concentration of copper ions can reach 14000ppm or more, the use amount of the etching solution is effectively reduced, and the cost is saved.

(3) The etching solution in this application is extremely low to glass corrosion degree, and the base plate can be reworked and used again, practices thrift the base plate.

(4) After the etching solution is treated, the taper angle is 45-55 degrees, and the defects of subsequent film layer disconnection and the like can not be caused.

(5) After the auxiliary agent is added, the copper ions are increased by 100ppm each time, and the auxiliary agent with the weight of 0.05-0.15% of that of the main agent is supplemented into the system, so that an excellent etching effect can be achieved, and the etching stability is ensured.

Drawings

FIG. 1 SEM cross-sectional view of etched cross-section of example 1 with a copper ion concentration of 0ppm

Detailed Description

Copper metal etching solutions of examples 1 to 3 and comparative examples 1 to 4 were prepared according to the following table

TABLE 1 preparation of raw materials and proportions of examples and comparative examples

And (3) performance testing:

1. metal residue, chamfer and crack: the etching solutions obtained in examples 1 to 3 and comparative examples 1 to 4 were introduced into a solution storage system of an etching machine, a copper/titanium (4000/300a) film panel was placed on the etching machine, during the spraying process, the concentration of copper ions in the solution was recorded using an instrument, etching was performed under the following etching conditions, after the etching was completed, a sample was cleaned with ultrapure water and prepared, etching characteristics were observed by SEM, and it was observed whether or not there were significant metal residues, chamfers, and cracks on the surface of the copper/titanium film after the etching was completed.

2. CD-Loss and slope angle: the etching solutions obtained in examples and comparative examples were subjected to glass substrate etching experiments, and the amount of loss of lines before and after etching and the slope angle after etching were examined by SEM.

3. The highest copper loading: the etching solutions obtained in examples and comparative examples were subjected to an experiment for etching a glass substrate, and the lifetime of the etching solution was evaluated by using the amount of copper dissolved in the etching solution when any of the slope angle, the CD-Loss value, and the glass corrosion rate exceeded the values described in table 2 as the maximum copper loading amount.

4. Glass corrosion rate: the etching solutions obtained in examples and comparative examples were subjected to an experiment for etching a glass substrate, and the difference in height between an etched portion and a non-etched portion was measured by a contact roughness meter to determine the etching rate.

The results of the performance tests are shown in the table below.

Table 2 results of performance testing

Through the analysis of examples and comparative examples, the content of fluorine ions is low and titanium residue is serious in comparative example 1; the etching solution obtained in comparative example 2, which does not contain hydrofluoric acid and the etching solution obtained in comparative example 3, does not etch the metal layer; in comparative example 4, the negative ion content was high and the glass corrosion was severe.

Claims

1. The copper metal etching solution composition is characterized in that the preparation raw materials comprise: a main agent and an auxiliary agent;

the preparation raw materials of the main agent comprise: peroxide, fluoride ion source, acid substance, amino compound, stabilizer, heterocyclic compound and ultrapure water.

2. The copper metal etchant composition according to claim 1, wherein the preparation raw material of the main agent comprises, by mass: 1 to 20% of peroxide, 0.01 to 1% of fluoride ion source, 1 to 15% of acidic substance, 0.1 to 15% of amino compound, 0.01 to 1% of stabilizer, 0.01 to 1% of heterocyclic compound and the balance of ultrapure water.

3. The copper metal etchant composition according to claim 1 or 2, wherein the peroxide is at least one selected from the group consisting of hydrogen peroxide, potassium peroxide, peracetic acid, magnesium peroxide, and sodium percarbonate.

4. The copper metal etchant composition of claim 3 wherein the fluoride ion source is selected from at least one of sodium fluoride, hydrofluoric acid, ammonium fluoride, ammonium bifluoride, potassium fluoride, ammonium fluoroborate, and trifluoroacetic acid.

5. The copper metal etchant composition of claim 4 wherein the fluoride ion source is hydrofluoric acid.

6. The copper metal etchant composition of claim 2, wherein the acidic material is at least one selected from the group consisting of magnesium salts of fatty acids, glycolic acid, diethylenetriamine pentamethylenephosphonic acid, sulfamic acid, N-hydroxyethylethylenediamine triacetic acid, diethylenetriamine pentaacetic acid, and tartaric acid.

7. The copper metal etchant composition of claim 1 wherein the amino compound is at least one selected from the group consisting of ethylenediamine, diethanolamine, diethylaminopropylamine, dimethylethanolamine, propylenediamine, tetramethylammonium oxide, triethanolamine, isopropanolamine, dimethylethylenediamine, and tris (hydroxymethyl) aminomethane.

8. The copper metal etchant composition according to claim 1, wherein the stabilizer is at least one selected from the group consisting of hydroxyethylidene diphosphonic acid, phenylcarbonyldiamide, p-aminophenylcarbonyldiamide, polyacrylamide, sodium p-hydroxybenzenesulfonate, p-aminophenylcarbonyldiamide, p-hydroxybenzenesulfonic acid, and dipicolinic acid.

9. The copper metal etchant composition of claim 1, wherein the adjuvant is prepared from the following raw materials: fluoride ion source, acidic material, amino compound, stabilizer, heterocyclic compound and ultrapure water.

10. A method of using the copper metal etchant composition according to any one of claims 1 to 9, wherein the copper metal etchant composition is prepared by bringing a main agent of the copper metal etchant composition into contact with a copper-containing metal layer and then adding an auxiliary agent of the copper metal etchant composition.