WO2020015193A1

WO2020015193A1 - Copper/molybdenum etching solution composition and use thereof

Info

Publication number: WO2020015193A1
Application number: PCT/CN2018/108280
Authority: WO
Inventors: 吴豪旭; 赵芬利; 梅园
Original assignee: 深圳市华星光电半导体显示技术有限公司
Priority date: 2018-07-19
Filing date: 2018-09-28
Publication date: 2020-01-23
Also published as: CN108950557A

Abstract

Disclosed is a copper/molybdenum etching solution composition, comprising the following components by weight percentage: hydrogen peroxide 5-30％, hydrogen peroxide stabilizer 0.1-5％, etching corrosion inhibitor 0.001-0.2％, etching additive 5-20％, pH regulator 0.1-5％, etching shape controlling agent 2-15％, surfactant 0.1-1％, and a balance of deionized water, the etching shape controlling agent being a hydramine compound. The etching solution composition does not contain a fluoride compound, is environmentally friendly, can reduce harm to an operator, and reduce costs of processing spent solution. The etching solution composition can also provide a stable etching process and a moderate etching rate, while effectively avoiding the occurrence of undercutting, so as to finally obtain an excellently shaped metal wiring structure. Further disclosed is use of the copper/molybdenum etching solution composition in the fabrication of a display panel.

Description

Copper / molybdenum etching solution composition and application thereof

Technical field

The invention relates to the technical field of etching solution, in particular to a copper / molybdenum etching solution composition and application thereof.

Background technique

In current generations of TFT-LCD liquid crystal displays, in order to meet the wiring requirements of large-sized panels, the gate and data metal wiring mostly use copper alloy materials, and titanium, molybdenum, etc. are used as the lower barrier metal.

The existing copper / molybdenum etching solution basically contains fluoride. Although the presence of fluoride can have a certain beneficial effect on the removal of the residue of the molybdenum layer during the etching process, the presence of fluoride will react with the substrate glass. , F- and SiO ₂ chemically affect the substrate glass and affect the later process performance. Moreover, fluoride is an environmentally unfriendly substance, which poses challenges to the health of operators and the cost of wastewater treatment. In addition, the undercut phenomenon caused by the mismatch of the copper / molybdenum etching rate during the reaction of the existing etching solution (as shown by the circled part in Figure 1), the existence of the undercut may cause the insulation layer to break and the TFT Problems such as electrical offset affect the panel display effect. Based on the many problems of the existing copper / molybdenum etching solution, it is necessary to provide an environmentally friendly copper / molybdenum etching solution to solve the problem that the copper / molybdenum stack is prone to hollowing out during the etching process.

technical problem

In view of this, the present invention provides a copper / molybdenum etchant composition containing no fluoride. The etchant is environmentally friendly and has excellent etching effect. The etching process is stable, the etching rate is moderate, and the metal can be effectively suppressed. The formation of residues solves the problem that the copper / molybdenum laminate is prone to hollowing out during the etching process, and finally obtains a well-shaped wiring structure.

Technical solutions

Specifically, in a first aspect, the present invention provides a copper / molybdenum etching solution composition, the etching solution composition includes the following components by weight fraction: 5-30% hydrogen peroxide, 0.1 hydrogen peroxide stabilizer ~ 5%, etching inhibitor 0.001 ~ 0.2%, etching additive 5 ~ 20%, pH adjuster 0.1 ~ 5%, etching shape control agent 2 ~ 15%, surfactant 0.1 ~ 1%, and the balance of Ionized water, and the etching shape control agent is an alcohol amine compound. The etching inhibitor is selected from benzoxazole compounds; and the etching additive is selected from tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, succinic acid, malic acid, At least one of glycolic acid, citric acid, phthalic acid, salicylic acid, alanine, asparagine, and arginine.

In the present invention, the alcohol amine compound includes an alkanolamine having 1 to 10 carbon atoms.

In the present invention, the alkanolamine includes isopropanolamine, N-ethylethanolamine, diethylene glycolamine, triisopropanolamine, monoethanolamine, N, N-dimethylethanolamine, and N, N-diethylamine. One or more of the ethanolamines.

In the present invention, the surfactant includes at least one of polyethylene glycol and polyacrylic acid amine.

In the present invention, the weight fraction of the etching shape control agent is 2 to 10%.

In the present invention, the weight fraction of the etching shape control agent is 5 to 15%.

In the present invention, the hydrogen peroxide stabilizer is selected from the group consisting of N-phenylurea, N, N'-diphenylurea, 1,3-diethyl-1,3-diphenylurea, and 4-methyl. At least one of thiosemicarbazide and diphenylsemicarbazide.

In the present invention, the pH adjusting agent is selected from at least one of phosphate, hydrogen phosphate and organic hypophosphite, and the pH of the etchant composition is controlled to be 3-6.

The copper / molybdenum etching solution composition provided by the first aspect of the present invention does not contain fluoride, is environmentally friendly, can reduce hazards to operators, and reduce the cost of waste liquid treatment. It includes specific components with specific contents. Under the synergistic effect, it has excellent etching effect, stable etching process, moderate etching rate, can effectively avoid the occurrence of hollowing out, and finally obtain a metal wiring structure with a good shape.

Specifically, in a second aspect, the present invention provides a copper / molybdenum etching solution composition. The etching solution composition includes the following components in weight fractions: hydrogen peroxide 5-30%, hydrogen peroxide stabilizer 0.1. ~ 5%, etching inhibitor 0.001 ~ 0.2%, etching additive 5 ~ 20%, pH adjuster 0.1 ~ 5%, etching shape control agent 2 ~ 15%, surfactant 0.1 ~ 1%, and the balance of Ionized water, and the etching shape control agent is an alcohol amine compound.

In the present invention, the etching inhibitor is selected from azole compounds.

In the present invention, the etching additive is selected from tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, succinic acid, malic acid, glycolic acid, citric acid, phthalic acid, At least one of salicylic acid, alanine, asparagine, and arginine.

The copper / molybdenum etching solution composition provided by the second aspect of the present invention does not contain fluoride, is environmentally friendly, can reduce hazards to operators, and reduce the cost of waste liquid treatment. It includes specific content of specific components. Under the synergistic effect, it has excellent etching effect, stable etching process, moderate etching rate, can effectively avoid the occurrence of hollowing out, and finally obtain a metal wiring structure with a good shape.

In a third aspect, the present invention provides an application of the above-mentioned copper / molybdenum etchant composition in the preparation of a display panel, the application comprising: using the copper / molybdenum etchant composition to etch a copper / molybdenum film To form a gate and / or a source / drain.

Beneficial effect

The copper / molybdenum etching solution composition provided by the embodiment of the present invention is used to etch the copper / molybdenum film, which does not contain fluoride, so it will not cause damage to the substrate glass and affect the later process performance. In addition, it has an excellent etching effect, which can effectively avoid problems such as breakage of the insulating layer and electrical offset of the TFT caused by the existence of the hollowing phenomenon, and improve the display effect of the panel. In addition, the copper / molybdenum etchant composition according to the embodiment of the present invention can be repeatedly used, which reduces the difficulty of wastewater treatment, and thus can effectively reduce the manufacturing cost of the panel.

The advantages of the present invention will be partially explained in the following description, part of which is obvious from the description, or can be learned through the implementation of the embodiments of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional scanning electron microscope image of a copper / molybdenum film that is hollowed out after the copper / molybdenum film is etched by using an existing etching solution;

2 is a cross-sectional scanning electron microscope image of a copper / molybdenum film after the copper / molybdenum film is etched by using the copper / molybdenum etching solution composition of Embodiment 1 of the present invention;

FIG. 3 is a scanning electron microscope image of the copper / molybdenum film after the copper / molybdenum film is etched by using the copper / molybdenum etching solution composition of Embodiment 1 of the present invention at another angle.

Best Mode of the Invention

The following is a preferred implementation of the embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the embodiment of the present invention, several improvements and retouching can be made. These improvements He retouching is also considered as the protection scope of the embodiments of the present invention.

The embodiment of the present invention provides a copper / molybdenum etching solution composition. The etching solution composition includes the following components in weight fractions: 5-30% hydrogen peroxide, 0.1-5% hydrogen peroxide stabilizer, and etching. Corrosion inhibitor 0.001 ~ 0.2%, etching additives 5 ~ 20%, pH adjuster 0.1 ~ 5%, etching shape control agent 2 ~ 15%, surfactant 0.1 ~ 1%, and the balance of deionized water. The etching shape control agent is an alcohol amine compound.

In the embodiment of the present invention, hydrogen peroxide is used as the main oxidant of copper and molybdenum. Further optionally, the content of the hydrogen peroxide is 5.5% -25%, 8-15%, and 6.5-10%. When the content of hydrogen peroxide is insufficient, the acidification of copper / molybdenum is insufficient, so that etching cannot be achieved. When the content of hydrogen peroxide is too high, the etching rate will be too fast, making it difficult to control the progress of the etching.

In the embodiment of the present invention, the etching shape control agent is beneficial to adjust the etching cone angle, so that the etching cone angle is controlled in a suitable range of 30 ° -60 °, and the etching cone angle can be further controlled to an ideal 45 ° ± 5. At the same time, ideal etching straightness can be obtained. In the embodiment of the present invention, the alcohol amine compound is selected as the shape control agent, which can also effectively suppress the decomposition of hydrogen peroxide caused by the increase of the metal ion concentration in the system as the etching continues, and maintain the etching effect of the etching solution. And its greater hydrophilicity can inhibit the generation of metal residues. Specifically, the alcohol amine compound includes an alkanolamine having 1 to 10 carbon atoms; the alkanolamine may be, but is not limited to, isopropanolamine, N-ethylethanolamine, diethylene glycolamine, One or more of triisopropanolamine, monoethanolamine, N, N-dimethylethanolamine, and N, N-diethylethanolamine.

In the embodiment of the present invention, in order to obtain a better etching effect and obtain an ideal etching cone angle and etching straightness, it is necessary to reasonably control the content of the etching shape control agent in the etching solution for different thickness copper / molybdenum film layers. The copper / molybdenum film layer refers to a laminate formed by a copper layer (which may be copper or a copper alloy) and a molybdenum layer. Optionally, when the thickness of the copper layer is below 4000Å, the weight fraction of the etched shape control agent is 2-10%, further 2% -4%, 5% -9%. When the thickness of the copper layer is 4000 Å or more, the weight fraction of the etched shape control agent is 5 to 15%, further 6 to 12%, and 12 to 15%.

In the embodiment of the present invention, the addition of a surfactant is beneficial to the elimination of molybdenum residues, and it is also beneficial for the etching inhibitor to form a dense film on the metal surface. The surfactant includes at least one of polyethylene glycol and polyacrylic acid amine. Further, the weight fraction of the surfactant is 0.2 to 0.8% and 0.5 to 0.7%.

In the embodiment of the present invention, the etching inhibitor can shield the metal ions generated after the etching, and functions as a cathodic corrosion inhibitor, inhibits the decomposition of the metal ions to the hydrogen peroxide, and thereby improves the uniformity of the etching. The etching inhibitor is selected from azole compounds, and the azole compounds include one of unsubstituted azole compounds, amino-substituted azole compounds, phenyl-substituted azole compounds, and benzoazole compounds. Or more. The azole compound may be imidazole or thiazole, and the benzoxazole compound includes one or more of a benzimidazole compound, a benzothiazole compound, and a benzotriazole compound. For example, it may be 1H-imidazole, 1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, 3-amino-1H-triazole, 1,3-thiazole, benzotriazole , Mercaptobenzothiazole, methylbenzotriazole, and the like, specifically, benzotriazole, mercaptobenzothiazole, methylbenzotriazole, and the like. Further, the content of the etching inhibitor is 0.02 to 0.1%, and 0.09 to 0.2%.

In the embodiment of the present invention, the etching additive can effectively regulate the etching rate of the etching solution, facilitate the etching of copper and molybdenum, and remove residues derived from molybdenum to obtain a good wiring cross-sectional shape. The etching additive is an organic acid, and may be specifically selected from tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, succinic acid, malic acid, glycolic acid, citric acid, and phthalic acid. At least one of formic acid, salicylic acid, alanine, asparagine, and arginine. Further, the etching additive is selected from a combination of any two or three of tartaric acid, malonic acid, benzoic acid, diglycolic acid, malic acid, glycolic acid, and citric acid. Under the combined effect of multiple organic acids, the etching rate can be better controlled and a better etching effect can be obtained. Further, the content of the etching additive is 6-10%, and 8-15%.

In the embodiment of the present invention, the hydrogen peroxide stabilizer can prevent a violent chain reaction of hydrogen peroxide, prevent an excessively fast decomposition of hydrogen peroxide, so that the hydrogen peroxide can function smoothly and fully. The hydrogen peroxide stabilizer may be selected from N-phenylurea, N, N'-diphenylurea, 1,3-diethyl-1,3-diphenylurea, 4-methylthioamino At least one of urea and diphenylsemicarbazide. Further, the content of the hydrogen peroxide stabilizer is 0.5 to 2%, and 0.9 to 4%.

In the embodiment of the present invention, the pH adjusting agent may be selected from the group consisting of phosphate, hydrogen phosphate, and organic hypophosphite, and may be at least one of ammonium phosphate, diammonium hydrogen phosphate, potassium dihydrogen phosphate, and ammonium dihydrogen phosphate. Species. The pH of the etching solution composition is controlled between 3 and 6, and further controlled between 4.5 and 5.5. Too low pH results in too much acidity, which will damage other film layers during the etching process. Too high pH will cause the decomposition of hydrogen peroxide, which is not conducive to the smooth progress of the reaction. Specifically, the content of the pH adjusting agent is determined according to the final pH of the etching solution.

In the embodiment of the present invention, a preferred etching temperature of the etchant composition is 30 to 35 ° C.

The copper / molybdenum etching solution composition provided by the embodiment of the present invention does not contain fluoride and is environmentally friendly, which can reduce the harm to operators and reduce the cost of waste liquid treatment. The etching process is stable and the etching rate is moderate, which can effectively avoid digging. The occurrence of the void phenomenon finally obtains a metal wiring structure with a good shape.

The embodiment of the present invention also provides an application of the above-mentioned copper / molybdenum etching solution composition in the preparation of a display panel. Specific applications include the use of the copper / molybdenum etching solution composition for copper during the preparation of a TFT array substrate. / Mo film is etched to form metal wiring structures such as gate, source and drain. The display panel may be a liquid crystal display panel or an OLED display panel.

The following further describes the embodiments of the present invention in multiple examples:

Example 1

A copper / molybdenum etching solution composition includes the following weight fractions of each component: hydrogen peroxide 5.5%, N-phenylurea 0.85%, 5-phenyl-1H-tetrazole 0.04%, citric acid 10.0%, The pH adjusting agent is 0.1-5%, monoethanolamine 8%, polyethylene glycol 0.4%, and the balance of deionized water. The pH value of the etching solution is 4.7.

Example 2

A copper / molybdenum etching solution composition includes the following weight fractions of each component: hydrogen peroxide 6.5%, N, N'-diphenylurea 0.9%, 5-amino-1H-tetrazole 0.05%, glycolic acid And citric acid 10%, pH adjuster 0.1-5%, N-ethylethanolamine 7%, polyacrylamine 0.6%, and the balance of deionized water, the pH of the etching solution is 4.8.

Example 3

A copper / molybdenum etching solution composition includes the following weight fractions of each component: 10.0% hydrogen peroxide, N-phenylurea and N, N'-diphenylurea 1.2%, 3-amino-1H-tri Azole 0.09%, benzoic acid and tartaric acid 8.5%, pH adjuster 0.1-5%, isopropanolamine 5%, polyethylene glycol 1%, and the balance of deionized water, the pH of the etching solution was 4.9.

Example 4

A copper / molybdenum etching solution composition including the following weight fractions of various components: hydrogen peroxide 8%, N-phenylurea 2%, methylbenzotriazole 0.02%, benzoic acid and citric acid 9%, The pH adjusting agent is 0.1-5%, diethylene glycol amine 12%, polyacrylamine 0.2%, and the balance of deionized water. The pH of the etching solution is 5.2.

Example 5

A copper / molybdenum etching solution composition includes the following components in weight fractions: 6% hydrogen peroxide, diphenylsemicarbazide 0.8%, benzotriazole 0.06%, glycolic acid, benzoic acid, and citric acid 8.5%, The pH adjuster is 0.1-5%, isopropanolamine 9%, polyethylene glycol 0.5%, and the balance of deionized water. The pH of the etching solution is 4.7.

Example 6

A copper / molybdenum etching solution composition includes the following weight fractions of each component: hydrogen peroxide 20%, N-phenylurea 3%, methylbenzotriazole 0.2%, tartaric acid, malic acid, and citric acid 6 %, PH adjuster 0.1-5%, diethylene glycol 6%, polyethylene glycol 0.2%, and the balance of deionized water, the pH of the etching solution is 5.2.

In order to evaluate the effect of the copper / molybdenum etchant composition of the embodiment of the present invention, the following etching performance tests were performed:

A 300 Å layer of molybdenum is deposited on a glass substrate, and a thickness of 7000 Å is deposited on the molybdenum layer The copper layer is then subjected to photolithography to form a pattern and make a test piece. During the photolithography process, the etching solution composition in the above specific embodiment was used for etching. The etching temperature during the etching process was 35 ° C. After the etching, the etching characteristics of the copper / molybdenum film were observed using a scanning electron microscope. The results are shown in Figure 2 As shown, FIG. 2 is a cross-sectional scanning electron microscope image of a copper / molybdenum film after the copper / molybdenum film is etched by using the copper / molybdenum etching solution composition of embodiment 1 of the present invention, and FIG. The scanning electron microscope image of the copper / molybdenum film after the copper / molybdenum film was etched by the copper / molybdenum composition at another angle, as can be seen from FIG. 2 and FIG. 3, a good cross-sectional shape was obtained after the etching, and A good etching straightness is formed, an etching cone angle of about 45 ° is formed, and the etchant composition of this embodiment does not damage the glass substrate, so the post-production performance of the panel can be improved.

It should be noted that, according to the disclosure and description of the foregoing description, those skilled in the art to which the present invention pertains can also make changes and modifications to the above embodiments. Therefore, the present invention is not limited to the specific embodiments disclosed and described above, and equivalent modifications and changes to the present invention should also fall within the protection scope of the claims of the present invention. In addition, although some specific terms are used in this specification, these terms are only for convenience of explanation and do not constitute any limitation to the present invention.

Claims

A copper / molybdenum etching solution composition including the following weight fractions of each component: 5-30% hydrogen peroxide, 0.1-5% hydrogen peroxide stabilizer, 0.001-0.2% etching inhibitor, and etching additive 5 ~ 20%, pH adjuster 0.1 ~ 5%, etching shape control agent 2 ~ 15%, surfactant 0.1 ~ 1%, and the balance of deionized water, the etching shape control agent is an alcohol amine compound,

Wherein the etching inhibitor is selected from benzoxazole compounds; and

The etching additive is selected from the group consisting of tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, succinic acid, malic acid, glycolic acid, citric acid, phthalic acid, and salicylic acid. At least one of amine, alanine, asparagine, and arginine.
The copper / molybdenum etching solution composition according to claim 1, wherein the alcohol amine compound includes an alkanolamine having 1 to 10 carbon atoms, and the alkanolamine includes isopropanolamine, N-ethyl One or more of ethanolamine, diethylene glycolamine, triisopropanolamine, monoethanolamine, N, N-dimethylethanolamine, and N, N-diethylethanolamine.
The copper / molybdenum etchant composition of claim 1, wherein the surfactant comprises at least one of polyethylene glycol and polyacrylic acid amine.
The copper / molybdenum etching solution composition according to claim 1, wherein a weight fraction of the etching shape control agent is 2 to 10%.
The copper / molybdenum etching solution composition according to claim 1, wherein a weight fraction of the etching shape control agent is 5 to 15%.
The copper / molybdenum etching solution composition according to claim 1, wherein the hydrogen peroxide stabilizer is selected from the group consisting of N-phenylurea, N, N'-diphenylurea, and 1,3-diethyl-1. At least one of 3-diphenylurea, 4-methylthiosemicarbazide, and diphenylsemicarbazide.
The copper / molybdenum etchant composition according to claim 1, wherein the pH adjuster is selected from at least one of phosphate, hydrogen phosphate, and organic hypophosphite, and the pH of the etchant composition is controlled at 3 ~ 6.
A copper / molybdenum etching solution composition including the following weight fractions of each component: 5-30% hydrogen peroxide, 0.1-5% hydrogen peroxide stabilizer, 0.001-0.2% etching inhibitor, and etching additive 5 ~ 20%, pH adjuster 0.1 ~ 5%, etching shape control agent 2 ~ 15%, surfactant 0.1 ~ 1%, and the balance of deionized water, the etching shape control agent is an alcohol amine compound.
The copper / molybdenum etching solution composition according to claim 8, wherein the alcohol amine compound includes an alkanolamine having 1 to 10 carbon atoms, and the alkanolamine includes isopropanolamine, N-ethyl One or more of ethanolamine, diethylene glycolamine, triisopropanolamine, monoethanolamine, N, N-dimethylethanolamine, and N, N-diethylethanolamine.
The copper / molybdenum etching solution composition according to claim 8, wherein the surfactant comprises at least one of polyethylene glycol and polyacrylic acid amine.
The copper / molybdenum etching solution composition according to claim 8, wherein a weight fraction of the etching shape control agent is 2 to 10%.
The copper / molybdenum etching solution composition according to claim 8, wherein a weight fraction of the etching shape control agent is 5 to 15%.
The copper / molybdenum etching solution composition according to claim 8, wherein the etching inhibitor is selected from benzoxazole-based compounds.
The copper / molybdenum etching solution composition according to claim 8, wherein the etching additive is selected from the group consisting of tartaric acid, malonic acid, benzoic acid, diglycolic acid, maleic acid, hydroxybutyric acid, lactic acid, succinic acid, and malic acid , Glycolic acid, citric acid, phthalic acid, salicylic acid, alanine, asparagine, and arginine.
The copper / molybdenum etching solution composition according to claim 8, wherein the hydrogen peroxide stabilizer is selected from the group consisting of N-phenylurea, N, N'-diphenylurea, and 1,3-diethyl-1 At least one of 3-diphenylurea, 4-methylthiosemicarbazide, and diphenylsemicarbazide.
The copper / molybdenum etchant composition according to claim 8, wherein the pH adjuster is selected from at least one of phosphate, hydrogen phosphate and organic hypophosphite, and the pH of the etchant composition is controlled at 3 ~ 6.
An application of the copper / molybdenum etchant composition according to claim 8 in the preparation of a display panel, the application comprising: using the copper / molybdenum etchant composition to etch a copper / molybdenum film to form a gate And / or source and drain.