Low-line-width high-precision Al / Mo etching solution for display panel and preparation method and application of low-line-width high-precision Al / Mo etching solution

Abstract

The invention provides a low-line-width high-precision Al / Mo etching solution for a display panel as well as a preparation method and application thereof. The low-line-width high-precision Al / Mo etching solution for the display panel comprises the following components in parts by weight: 5-15 parts of nitro organic acid; 10 to 60 parts of organic sulfonic acid; 1 to 10 parts of sulfonyl organic acid; 0.01 to 1 part of a surfactant; 10 to 40 parts of an alcohol solvent; and 20-60 parts of ultrapure water. The low-linewidth high-precision Al / Mo etching solution for the display panel can efficiently etch an Al / Mo composite metal layer, has the advantages of high etching precision and environmental friendliness, and can be widely applied to the field of manufacturing of display panel gates (Gate) and source / drain (S / D).

Description

Technical Field

[0001] This invention relates to etching solution technology, and more particularly to a low-linewidth, high-precision Al / Mo etching solution for display panels, its preparation method, and its application. Background Technology

[0002] Aluminum / molybdenum (Al / Mo) etchants are key chemicals in display panel (such as TFT-LCD and OLED) and semiconductor manufacturing, used to precisely etch metal layers to form circuit patterns. As display technologies advance towards higher resolution and greater flexibility, and semiconductor manufacturing processes move towards smaller nodes, the performance requirements for etchants are becoming increasingly demanding.

[0003] Currently, foreign companies such as Tokyo Ohka Kogyo (Japan), BASF (Germany), and Honeywell (USA) dominate the high-end market for etching solutions in high-generation panels (such as 10.5-generation lines) and advanced semiconductors (below 5nm) due to their technological accumulation. Their products have advantages such as high stability and low defect rate. In recent years, domestic companies have accelerated their catch-up efforts, increasing R&D investment and gradually breaking through key technologies such as high-purity chemicals and nanoscale etching, achieving partial domestic substitution of etching solutions.

[0004] Currently, domestically produced Al / Mo etching solutions are mainly divided into three categories: acidic, alkaline, and environmentally friendly. Acidic etching solution: The main components are phosphoric acid (H3PO4), nitric acid (HNO3), and acetic acid (CH3COOH). The etching rate and metal layer selectivity are controlled by adjusting the ratio. This system is mature and stable, but the cost of treating phosphoric acid waste liquid is high, which does not meet increasingly stringent environmental protection requirements.

[0005] Alkaline etching solutions are suitable for certain special processes, but they have a high corrosion rate on molybdenum, which can easily lead to critical dimension (CD) deviations, thus limiting their application.

[0006] Environmentally friendly etching solutions: In recent years, phosphorus-free and low chemical oxygen demand (COD) etching solutions have become the focus of research and development. For example, organic acids (citric acid, oxalic acid) or composite corrosion inhibitors are used to replace the traditional phosphoric acid system. However, the cost is high and the process window is narrow. They have not yet completely replaced the traditional etching solutions.

[0007] With the acceleration of domestic substitution, the demand for environmentally friendly etching solutions is increasing. Simultaneously, with the advancement of the "dual carbon" target, phosphorus-free and low-pollution etching solutions have become a key research focus. However, due to cost and process maturity limitations, large-scale application still requires time. Furthermore, emerging display technologies such as Micro LED and flexible OLED are placing even higher demands on the uniformity and selectivity of etching solutions, further driving the industry towards refinement.

[0008] Although domestic companies have achieved localization in some etching solution products, aluminum / molybdenum etching solution technology still has the following significant drawbacks in the high-end market: Process limitations: Traditional phosphate-based etchants do not provide ideal control over the aluminum / molybdenum selectivity ratio, easily leading to over-etching or residue of the molybdenum layer. In ultra-high resolution panel and advanced semiconductor manufacturing, existing etchants are insufficient for processing accuracy of linewidths <5μm, and side etching control is difficult to meet requirements, resulting in critical dimension deviations. Etching rate uniformity is poor, especially noticeable in large-area panels.

[0009] Environmental issues are prominent: wastewater from phosphorus-containing formulations is costly to treat, and COD levels generally exceed standards. Acidic systems emit large amounts of volatile organic compounds (VOCs), failing to comply with increasingly stringent environmental regulations. The use of heavy metal additives poses potential environmental pollution risks. Summary of the Invention

[0010] The purpose of this invention is to address the problems of poor etching effect and environmental pollution caused by traditional phosphate-based etching solutions by proposing a low-linewidth, high-precision Al / Mo etching solution for display panels. This etching solution can efficiently etch Al / Mo composite metal layers and has the advantages of high etching precision and environmental friendliness. It can be widely used in the manufacturing of display panel gates and source / drain electrodes.

[0011] It should be noted that, in this invention, unless otherwise specified, the specific meaning of "comprising" in relation to composition and description includes both open-ended meanings such as "comprising," "including," etc., and closed-ended meanings such as "composed of," "consisting of," etc., and similar meanings.

[0012] To achieve the above objectives, the technical solution adopted by the present invention is: a low-linewidth, high-precision Al / Mo etching solution for display panels, comprising the following components by weight ratio: 5-15 parts of nitro organic acids; 10-60 parts of organic sulfonic acid; 1-10 parts of sulfonyl organic acids; Surfactant 0.01-1 part; 10-40 parts of alcohol solvent; 20-60 parts of ultrapure water.

[0013] Furthermore, the nitro organic acid is an organic acid compound containing a nitro group, and the nitro organic acid is one or more of nitroacetic acid, 2-methyl-4-nitrobenzoic acid, nitroterephthalic acid, and m-nitrobenzoic acid.

[0014] Furthermore, the nitro organic acid is preferably nitroacetic acid.

[0015] Furthermore, the nitro organic acid is present in 8-12 parts.

[0016] Furthermore, the organic sulfonic acid is an organic sulfonic acid with a carbon chain of less than 8.

[0017] Furthermore, in this invention, any organic sulfonic acid with a carbon chain of less than 8 can be used to synergize with sulfonyl organic acids. Suitable organic sulfonic acids include one or more of methanesulfonic acid, sulfonic acid, 2-butylsulfonic acid, phenolic disulfonic acid, cyclopentanesulfonic acid, and propanesulfonic acid.

[0018] Furthermore, the organic sulfonic acid is preferably methanesulfonic acid.

[0019] Furthermore, the organic sulfonic acid is in the form of 30-60 parts.

[0020] Further, the sulfonoxy organic acid is one or more of (S)-2-amino-3-(4-(sulfonoxy)phenyl)propionic acid, 4-((fluorosulfonyl)oxy)benzoic acid, and 3,3',5-triiodo-L-methyladenosine 4'-O-sulfuric acid.

[0021] Furthermore, the sulfonoxy organic acid is preferably (S)-2-amino-3-(4-(sulfonoxy)phenyl)propionic acid.

[0022] Furthermore, the sulfonoxy organic acid is present in amounts of 3-5 parts.

[0023] Furthermore, the mass ratio of the nitro organic acid to the sulfonoxy organic acid is 1-5:1.

[0024] Furthermore, in this invention, any type of surfactant can be used to increase the dispersibility of the etching solution. Suitable surfactants include one or more of polyoxyethylene castor oil, polyoxyethylene phosphate, stearyl alcohol polyether-2 phosphate, alkylphenol polyoxyethylene phosphate, potassium monododecyl phosphate, and sodium dodecylbenzene sulfonate.

[0025] Furthermore, the surfactant is preferably polyoxyethylene castor oil.

[0026] Further, the surfactant is 0.5-1 part.

[0027] Furthermore, in this invention, the alcohol solvent is an alcohol solvent well known to those skilled in the art, such as one or more of methanol, ethanol, 1,2-propanediol and butanol.

[0028] Furthermore, the alcohol solvent is 15-20 parts.

[0029] Furthermore, the ultrapure water is deionized water with a resistivity of at least 18 MΩ.

[0030] Furthermore, the ultrapure water is 30-50 parts.

[0031] Another object of the present invention discloses a method for preparing a low-linewidth, high-precision Al / Mo etching solution for display panels, comprising the following steps: Weigh out the respective amounts of each component; add all components to a container and stir at 30-40℃ until all components are completely dissolved to obtain a low linewidth, high-precision Al / Mo etching solution.

[0032] Another objective of this invention is to disclose the application of a low-linewidth, high-precision Al / Mo etching solution for display panels in the field of etching Al / Mo composite metal layers.

[0033] Furthermore, the method of etching the Al / Mo composite metal layer using a low-linewidth, high-precision Al / Mo etching solution for display panels includes the following steps: Step 1: Immerse the substrate coated with the Al / Mo composite metal layer in the low linewidth, high-precision Al / Mo etching solution for the display panel and etch for a certain period of time; Step 2: Rinse with deionized water after etching and purge with N2.

[0034] Furthermore, the etching time for step 1 is 60-110 seconds.

[0035] Furthermore, the deionized water rinsing time in step 2 is 60-110 seconds.

[0036] Furthermore, the N2 purging time in step 2 is 20-40 seconds.

[0037] The present invention relates to a low-linewidth, high-precision Al / Mo etching solution for display panels, its preparation method, and its application, which have the following advantages compared with existing technologies: 1) The low linewidth, high precision Al / Mo etching solution for display panels of the present invention can effectively complete the etching of Al / Mo composite metal layers, has a high etching selectivity for Al / Mo, and can form a lower Taper angle; at the same time, the etching solution formulation of the present invention does not contain phosphorus components and has a lower chemical oxygen demand (COD).

[0038] 2) The sulfonoxy group of the sulfonoxy organic acid and the nitro group of the nitro organic acid of the present invention have strong electron-withdrawing properties. The nitro organic acid and the sulfonoxy organic acid form ion pairs, which bind them tightly. At the same time, they also form a complex hydrogen bond network to increase the stability of the system. Among them, the preferred sulfonoxy organic acid is (S)-2-amino-3-(4-(sulfonoxy)phenyl)propionic acid, which is a chiral catalyst. It can also combine surfactants (such as polyoxyethylene castor oil) with nitro organic acids (such as nitroacetic acid) and organic sulfonic acids (such as methanesulfonic acid) to form chiral molecules, so that the organic acid molecules have good dispersibility and achieve higher precision etching.

[0039] 3) The organic sulfonic acid selected in this invention is an organic sulfonic acid with a carbon chain of less than 8. It has low steric hindrance and can be embedded in a large number of surfactant (such as polyoxyethylene castor oil) molecules, effectively ensuring etching efficiency.

[0040] 4) All components of the low-linewidth, high-precision Al / Mo etching solution for the display panel of this invention are biodegradable, environmentally friendly, and meet the requirements of green chemistry.

[0041] Therefore, the low-linewidth, high-precision Al / Mo etching solution for display panels of this invention has good application prospects and large-scale promotion potential in the field of etching Al / Mo composite metal layers. Attached Figure Description

[0042] Figure 1 The cross-sectional morphology of the sample etched using Example 1 was captured by SEM at 40,000x magnification. Figure 2 The image shows the cross-sectional morphology of the etched sample (Comparative Example 1) magnified at 40,000x using SEM. Detailed Implementation

[0043] The present invention will be further described below with reference to embodiments. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that: Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0044] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0045] In this specification, the numerical range indicated by "above" or "below" refers to the numerical range that includes the stated number.

[0046] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0047] In this specification, the terms "optional" or "optional" are used to indicate the use or omission of certain substances, components, procedures, application conditions, etc.

[0048] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be 15-25℃.

[0049] Unless otherwise specified, all reagents or instruments used in this instruction manual are commercially available products.

[0050] Examples 1-7 Examples 1-7 disclose various low-linewidth, high-precision Al / Mo etching solutions for display panels. The components and their mass fractions are shown in Table 1. The preparation method is as follows: weigh out the respective amounts of each component; add all components to a container and stir at 30-40°C until all components are completely dissolved.

[0051] Table 1. Components and mass fractions of low-linewidth, high-precision Al / Mo etching solutions for display panels in Examples 1-7

[0052] Comparative Examples 1-4 Comparative Examples 1-4 disclose various etching solutions, the components and mass fractions of which are shown in Table 2, and their preparation methods are the same as those in Example 1.

[0053] Table 2. Components and mass fractions of etching solutions for Comparative Examples 1-4

[0054] The display panels of Examples 1-7 were tested using low-linewidth, high-precision Al / Mo etching solution and the etching solutions of Comparative Examples 1-4, respectively. The test methods and results are as follows: Table 3 Test Results

[0055] As can be seen from Table 3, the display panel using the embodiment of the present invention has a Taper angle of <26° etched with a low linewidth and high precision Al / Mo etching solution, and the morphology is good. However, the comparative example has a Taper angle of 40-55°, and morphological defects such as top Mo protrusion / retraction occur.

[0056] Comparative Example 1 lacks (S)-2-amino-3-(4-(sulfonoxy)phenyl)propionic acid, which prevents organic sulfonic acid, nitro organic acid and surfactant from binding, affecting the etching morphology and potentially causing slight shrinkage of the top Mo. Comparative Example 2 uses citric acid instead of organic sulfonic acid. Due to the reduction of sulfonyl groups in the solution, they cannot combine with nitro groups, resulting in uneven etching of the metal layer and a larger taper angle. Comparative Example 3 uses acetic acid instead of nitro organic acid. Since it cannot provide strong electron-withdrawing groups, the synergistic effect of the two acids is insufficient, and the etching morphology cannot be guaranteed.

[0057] Figure 1 The cross-sectional morphology of the sample etched using Example 1 was captured by SEM at 40,000x magnification. Figure 2 The image shows the cross-sectional morphology of the etched sample (Comparative Example 1) magnified at 40,000x using SEM.

[0058] from Figure 1 It can be seen that Taper is only 23.6°, from Figure 2 It can be seen that Taper is at 49.4°, through Figure 1 and Figure 2 The comparison shows that Figure 2 After etching, the Taper is higher and there is a slight shrinkage of the top Mo.

[0059] in: Performance 1: Topography and Taper Angle Testing Methods The Al / Mo samples were etched using the etching solutions of the above embodiments and comparative examples of the present invention. The cleaning process included the following steps: Step 1: Prepare the etching solution according to the proportions in the embodiment, heat it in a water bath to 40°C, immerse the sample in the etching solution and agitate until the sample transmits light, indicating that the etching is complete in the depth direction. The final etching time is 50% longer than the Etching Complete Time (EPD). Step 2: Rinse the Al / Mo sample in ultrapure water at least twice and dry it with nitrogen gas.

[0060] Step 3: Observe the morphology of the sample using a SEM with a linewidth of less than 5 μm and measure and record the Taper angle.

[0061] The ultrapure water used in steps 1 and 2 is deionized water with a resistance of at least 18 MΩ.

[0062] It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the invention. Furthermore, it should be understood that after reading the technical description of this invention, those skilled in the art can make various alterations, modifications, and / or variations to the invention, and all such equivalent forms also fall within the scope of protection defined by the appended claims.

Claims

1. A low-linewidth, high-precision Al / Mo etching solution for display panels, characterized in that, The components include the following weight proportions: 5-15 parts of nitro organic acids; 10-60 parts of organic sulfonic acid; 1-10 parts of sulfonyl organic acids; Surfactant 0.01-1 part; 10-40 parts of alcohol solvent; 20-60 parts of ultrapure water.

2. The low-linewidth, high-precision Al / Mo etching solution for display panels according to claim 1, characterized in that, The nitro organic acid is one or more of nitroacetic acid, 2-methyl-4-nitrobenzoic acid, nitroterephthalic acid, and m-nitrobenzoic acid.

3. The low-linewidth, high-precision Al / Mo etching solution for display panels according to claim 1, characterized in that, The organic sulfonic acid is an organic sulfonic acid with a carbon chain of less than 8.

4. The low-linewidth, high-precision Al / Mo etching solution for display panels according to claim 1, characterized in that, The sulfonoxy organic acid is one or more of (S)-2-amino-3-(4-(sulfonoxy)phenyl)propionic acid, 4-((fluorosulfonyl)oxy)benzoic acid, and 3,3',5-triiodo-L-methyladenosine 4'-O-sulfuric acid.

5. The low-linewidth, high-precision Al / Mo etching solution for display panels according to claim 1, characterized in that, The mass ratio of the nitro organic acid to the sulfonoxy organic acid is 1-5:

1.

6. The low-linewidth, high-precision Al / Mo etching solution for display panels according to claim 1, characterized in that, The surfactant is one or more of the following: polyoxyethylene castor oil, polyoxyethylene phosphate, stearyl alcohol polyether-2 phosphate, alkylphenol polyoxyethylene phosphate, potassium monododecyl phosphate, and sodium dodecylbenzene sulfonate.

7. The low-linewidth, high-precision Al / Mo etching solution for display panels according to claim 1, characterized in that, The alcohol solvent is one or more of methanol, ethanol, 1,2-propanediol and butanol.

8. A method for preparing a low-linewidth, high-precision Al / Mo etching solution for a display panel according to any one of claims 1-7, comprising the following steps: Weigh out the respective amounts of each component; add all components to a container and stir at 30-40℃ until all components are completely dissolved to obtain a low linewidth, high-precision Al / Mo etching solution.

9. The application of the low-linewidth, high-precision Al / Mo etching solution for display panels as described in any one of claims 1-7 in the field of etching Al / Mo composite metal layers.

10. The application according to claim 9, characterized in that, The method for etching the Al / Mo composite metal layer of the display panel using a low-linewidth, high-precision Al / Mo etching solution includes the following steps: Step 1: Immerse the substrate coated with the Al / Mo composite metal layer in the low linewidth, high-precision Al / Mo etching solution for the display panel and etch for a certain period of time; Step 2: Rinse with deionized water after etching and purge with N2.

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