Long-life etching solution for copper-molybdenum structure and preparation method and etching method thereof

Abstract

The application provides a long-life etching solution for copper-molybdenum structure, a preparation method and an etching method, and the long-life etching solution comprises the following components in percentage by weight: 3-12% of an oxidizing agent; 5-11% of an organic acid chelating agent; 0.5-2% of a surfactant; and the balance of deionized water; the organic acid chelating agent comprises any one or a combination of at least two of alanine, glutamic acid, aminobutyric acid, glycine, phenylalanine, tryptophan, histidine and arginine. The etching solution provided by the application has a long copper life, high stability, and solves the problem of chamfering of copper-molybdenum film layers which is very common.

Description

Technical Field

[0001] This invention belongs to the field of copper-molybdenum layer structure etching technology, and relates to a long-life etching solution for copper-molybdenum structures, its preparation method and etching method. Background Technology

[0002] Copper-molybdenum is currently the mainstream film layer structure for TFT (thin-film transistor) display panels. Developing an environmentally friendly and long-life etching solution is crucial.

[0003] The current etching solution formulations used for copper-molybdenum films are quite complex, typically containing organic acids, organic bases, pH adjusters, stabilizers, inhibitors, etc. Meanwhile, to prevent chamfering, the usual solution is to add phosphorus-containing substances, but the addition of phosphorus-containing substances is extremely environmentally unfriendly.

[0004] For example, CN109234736A discloses a long-life copper-molybdenum etching solution, comprising: a mother solution and a daughter solution; the main components of the mother solution include hydrogen peroxide, a modifier, a stabilizer, an organic acid, an inhibitor, and a pH adjuster, with the remainder being deionized water; the main components of the daughter solution include a solvent, the organic acid, the inhibitor, and the stabilizer. The long-life copper-molybdenum etching solution and etching method provided by this invention, by adding a combination of solvent, organic acid, inhibitor, and stabilizer to an etching solution with a certain copper ion concentration, further extends the service life of the etching solution and further improves the stability of the etching quality. However, the formulation of the etching solution in this invention is relatively complex.

[0005] Therefore, in this field, there is a desire to develop an etchant for copper-molybdenum structures that has a simple formulation, can prevent chamfering, and has good stability and a long lifespan. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide a long-life etching solution for copper-molybdenum structures, along with its preparation and etching methods. This invention utilizes an organic acid chelate compound, eliminating the need for phosphorus-containing compounds, inhibitors, and pH adjusters, making it environmentally friendly. It also solves the common chamfering problem in copper-molybdenum films while exhibiting excellent stability.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising, by weight percentage, the following components:

[0009]

[0010] The organic acid chelating agent includes any one or a combination of at least two of alanine, glutamic acid, aminobutyric acid, glycine, phenylalanine, tryptophan, histidine, and arginine.

[0011] The long-life etching solution provided by this invention comprises a combination of an oxidant, an organic acid chelating agent, a surfactant, and deionized water. Through the screening and synergistic compounding of specific components, especially the introduction of the organic acid chelating agent, the etching solution exhibits a long copper lifetime, high stability, and solves the chamfering problem commonly found in copper-molybdenum films. The specific organic acid chelating agent added in this invention has excellent complexing ability, which can effectively improve the copper lifetime and stability of the etching solution.

[0012] Existing technical solutions generally require the addition of other pH adjusters, but the present invention only requires a combination of oxidants, organic acid chelating agents and surfactants, without the need to add other pH adjusters, to achieve the same or even better results.

[0013] In this invention, the amount of oxidant used in the long-life etching solution can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, etc. by weight percentage, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0014] In this invention, the amount of organic acid chelating agent in the long-life etching solution can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, etc. by weight percentage, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0015] In this invention, the amount of surfactant in the long-life etching solution can be 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc., by weight percentage, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0016] In this invention, the amount of deionized water used is a surplus, that is, the amount of deionized water used is such that the sum of the weight percentages of all components is 100%.

[0017] In this invention, "long life" in the long life etching solution refers to the etching of copper-molybdenum structures using the etching solution, with a copper life of 7000-14000 ppm.

[0018] Preferably, the organic acid chelating agent further includes any one or a combination of at least two of the following: iminodiacetic acid, nitrotriacetic acid, ethylenediaminetetraacetic acid, trichloroacetic acid, malonic acid, malic acid, succinic acid, citric acid, acetic acid, glycolic acid, tartaric acid, and maleic acid.

[0019] Preferably, the oxidant includes hydrogen peroxide and / or persulfate.

[0020] Preferably, the surfactant comprises alcohol compounds and / or ether compounds.

[0021] Preferably, the alcohol compound includes any one or a combination of at least two of monohydric alcohols, dihydric alcohols, and trihydric alcohols.

[0022] Preferably, the alcohol compound includes 1,2-propanediol and / or glycerol.

[0023] Preferably, the ether compound includes any one or a combination of at least two of ethylene glycol butyl ether, methyl tert-butyl ether, ethyl ether, and propylene glycol methyl ether.

[0024] In a second aspect, the present invention provides a method for preparing a long-life etching solution as described in the first aspect, the method comprising the following steps:

[0025] The long-life etching solution is obtained by mixing the oxidant, organic acid chelating agent, surfactant and deionized water in the prescribed amounts.

[0026] As a preferred embodiment of the present invention, the preparation method includes the following steps:

[0027] The organic acid chelating agent, surfactant, oxidant and deionized water of the formula are added to the container in sequence and stirred evenly to obtain the long-life etching solution.

[0028] Thirdly, the present invention provides a method for etching a copper-molybdenum metal film layer using a long-life etchant as described in the first aspect, comprising the following steps:

[0029] (1) A substrate is provided, wherein the film layer of the substrate is a copper-molybdenum metal film layer;

[0030] (2) The copper-molybdenum metal film is etched using the long-life etching solution;

[0031] Preferably, the etching temperature is 30-35℃, such as 30℃, 31℃, 32℃, 33℃, 34℃, 35℃, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Compared with the prior art, the present invention has the following beneficial effects:

[0033] The long-life etching solution provided by this invention comprises a combination of oxidant, organic acid chelating agent, surfactant, and deionized water. Through the screening and synergistic compounding of specific components, especially the introduction of organic acid chelating agent, the etching solution has a long copper life, high stability, and solves the chamfering problem that is very common in copper-molybdenum films. Attached Figure Description

[0034] Figure 1 This is a front view of the SEM image of the specimen after etching in Example 4.

[0035] Figure 2 This is a top view of the SEM image of the specimen after etching in Example 4.

[0036] Figure 3 This is a front view of the SEM image of the specimen after etching in Comparative Example 3.

[0037] Figure 4 This is a top view of the SEM image of the specimen after etching in Comparative Example 3. Detailed Implementation

[0038] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0039] Example 1

[0040] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0041]

[0042] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of citric acid (3%) and glycine (6%), and the surfactant is 1,2-propanediol.

[0043] The preparation method includes the following steps:

[0044] The long-life etching solution is obtained by mixing the oxidant, organic acid chelating agent, surfactant and deionized water in the prescribed amounts.

[0045] Example 2

[0046] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0047]

[0048] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of glycolic acid (2.5%) and alanine (7.5%), and the surfactant is 1,2-propanediol.

[0049] The preparation method is the same as in Example 1.

[0050] Example 3

[0051] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0052]

[0053] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of malonic acid (5%) and phenylalanine (5%), and the surfactant is 1,2-propanediol.

[0054] The preparation method is the same as in Example 1.

[0055] Example 4

[0056] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0057]

[0058] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of malonic acid (3.5%) and arginine (7.5%), and the surfactant is 1,2-propanediol.

[0059] The preparation method is the same as in Example 1.

[0060] Example 5

[0061] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0062]

[0063] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of malonic acid (3.5%) and arginine (7.5%), and the surfactant is ethylene glycol butyl ether.

[0064] The preparation method is the same as in Example 1.

[0065] Example 6

[0066] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0067]

[0068] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of glycolic acid (2.5%) and alanine (7.5%), and the surfactant is ethylene glycol butyl ether.

[0069] The preparation method is the same as in Example 1.

[0070] Example 7

[0071] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0072]

[0073] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of glycolic acid (2.5%) and glycine (7.5%), and the surfactant is ethylene glycol butyl ether.

[0074] The preparation method is the same as in Example 1.

[0075] Example 8

[0076] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0077]

[0078] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of malonic acid (3%), glycine (7.5%) and tryptophan (0.5%), and the surfactant is ethylene glycol butyl ether.

[0079] The preparation method is the same as in Example 1.

[0080] Example 9

[0081] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0082]

[0083] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of malonic acid (3%), glycine (7.5%) and tryptophan (0.5%), and the surfactant is glycerol.

[0084] The preparation method is the same as in Example 1.

[0085] Example 10

[0086] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0087]

[0088] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of malonic acid (3.5%), alanine (6%) and tryptophan (0.5%), and the surfactant is glycerol.

[0089] The preparation method is the same as in Example 1.

[0090] Example 11

[0091] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0092]

[0093] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of citric acid (4%) and glycine (7%), and the surfactant is 1,2-propanediol.

[0094] The preparation method is the same as in Example 1.

[0095] Example 12

[0096] This embodiment provides a long-life etching solution for copper-molybdenum structures, the long-life etching solution comprising the following components by weight percentage:

[0097]

[0098] The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of citric acid (2%) and glycine (3%), and the surfactant is 1,2-propanediol.

[0099] The preparation method is the same as in Example 1.

[0100] Comparative Example 1

[0101] This comparative example provides an etching solution for copper-molybdenum structures, the etching solution comprising, by weight percentage, the following components:

[0102]

[0103] The oxidant is hydrogen peroxide, the organic base is isopropanolamine, the organic acid chelating agent is citric acid, the metal corrosion inhibitor is 3-amino-1,2,4-triazole, and the surfactant is 1,2-propanediol.

[0104] The etching solution is obtained by mixing the formulated amounts of oxidant, organic base, organic acid chelating agent, metal corrosion inhibitor, surfactant, and deionized water.

[0105] Comparative Example 2

[0106] This comparative example provides an etching solution for copper-molybdenum structures, the etching solution comprising, by weight percentage, the following components:

[0107]

[0108] The oxidant is hydrogen peroxide, the organic base is triethanolamine, the organic acid chelating agent is glycolic acid, the metal corrosion inhibitor is 3-amino-1,2,4-triazole, and the surfactant is 1,2-propanediol.

[0109] The preparation method is the same as that of Comparative Example 1.

[0110] Comparative Example 3

[0111] This comparative example provides an etching solution for copper-molybdenum structures, the etching solution comprising, by weight percentage, the following components:

[0112]

[0113] The oxidant is hydrogen peroxide, the organic base is diethylaminopropylamine, the organic acid chelating agent is malonic acid, the metal corrosion inhibitor is 3-amino-1,2,4-triazole, and the surfactant is 1,2-propanediol.

[0114] The preparation method is the same as that of Comparative Example 1.

[0115] Comparative Example 4

[0116] The only difference between this comparative example and Example 1 is that glycine is replaced with an equal weight of citric acid; that is, the organic acid chelating agent in this comparative example consists only of citric acid.

[0117] To evaluate the effectiveness of the etching solutions provided in the embodiments and comparative examples of the present invention, test pieces with deposited molybdenum monolayers and copper metal films, and with completed patterns, were immersed in the etching solution. After 2 minutes, they were rinsed with water and then dried for etching characteristic evaluation. The etching characteristics of the copper and molybdenum films after etching were observed using a scanning electron microscope. If no chamfers, residues, or other defects appeared, the result was considered good; if chamfers, residues, or other defects appeared, the result was considered poor.

[0118] The test results are shown in Table 1:

[0119] Table 1

[0120] Etching temperature (°C) Etching characteristics Copper lifetime (ppm) <![CDATA[taper( O )]]> chamfer Example 1 32 good 8000 53-60 none Example 2 31 good 7000 40-49 none Example 3 30 good 9000 51-57 none Example 4 32 good 14000 45-52 none Example 5 32 good 14000 35-42 none Example 6 33 good 8000 41-50 none Example 7 31 good 10000 46-53 none Example 8 30 good 10000 56-62 none Example 9 32 good 12000 35-41 none Example 10 32 good 12000 48-55 none Example 11 31 good 10000 31-40 none Example 12 31 good 7000 35-43 none Comparative Example 1 31 Poor 6000 40-48 have Comparative Example 2 30 Poor 8000 47-56 have Comparative Example 3 30 Poor 8000 31-37 have Comparative Example 4 32 Poor 5000 40-48 have

[0121] As can be seen from Table 1, the etching solution provided in the embodiments of the present invention is used to etch copper-molybdenum metal film layers. The etching characteristics are good, with no chamfers, no residues, and no other defects. Moreover, compared with existing etching solutions, it has a copper lifetime of equivalent or longer (7000-14000ppm).

[0122] When copper-molybdenum metal films were etched using the etching solutions provided in Comparative Examples 1-4, chamfers appeared in all cases, indicating poor etching characteristics.

[0123] Example 4: The front and top views of the SEM images of the specimen after etching are shown below. Figure 1 and Figure 2 As shown, from Figure 2 It can be seen that there is no molybdenum metal residue on the sample.

[0124] The front and top views of the SEM images of the specimen after etching in Comparative Example 3 are shown below. Figure 3 and Figure 4 As shown, from Figure 4 It can be seen that while chamfers appear after etching, there are also obvious molybdenum metal residues.

[0125] The applicant declares that this invention illustrates the long-life etching solution for copper-molybdenum structures, its preparation method, and etching method through the above embodiments. However, this invention is not limited to the above embodiments, meaning that this invention does not necessarily rely on the above embodiments for implementation. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of the raw materials used, additions of auxiliary components, and selection of specific methods all fall within the protection and disclosure scope of this invention.

Claims

1. A long-life etching solution for copper-molybdenum structures, characterized in that, The long-life etching solution consists of the following components by weight percentage: Oxidizing agent 10%; Organic acid chelating agent 11%; 1% surfactant; Deionized water balance; The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of 3.5% malonic acid and 7.5% arginine, and the surfactant is ethylene glycol butyl ether. The copper-molybdenum metal film was etched using the aforementioned etching solution. The etching characteristics were good, with no chamfers or residues. The copper lifetime was 14,000 ppm, and the taper was 35°-42°. Alternatively, 8% oxidant; Organic acid chelating agent 11%; 1% surfactant; Deionized water balance; The oxidant is hydrogen peroxide, the organic acid chelating agent is a combination of 3% malonic acid, 7.5% glycine and 0.5% tryptophan, and the surfactant is glycerol. The copper-molybdenum metal film was etched using the aforementioned etching solution. The etching characteristics were good, with no chamfers or residues. The copper lifetime was 12,000 ppm, and the taper was 35°-41°.

2. A method for preparing a long-life etching solution as described in claim 1, characterized in that, The preparation method includes the following steps: The long-life etching solution is obtained by mixing the oxidant, organic acid chelating agent, surfactant and deionized water in the prescribed amounts.

3. A method for etching a copper-molybdenum metal film using the long-life etchant as described in claim 1, characterized in that, Includes the following steps: (1) A substrate is provided, wherein the film layer of the substrate is a copper-molybdenum metal film layer; (2) The copper-molybdenum metal film is etched using the long-life etching solution.

4. The method for etching a copper-molybdenum metal film layer according to claim 3, characterized in that, The etching temperature is 30-35℃.

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