Copper-molybdenum etching solution for improving etching morphology and preparation method thereof

Abstract

The invention relates to the technical field of copper-molybdenum etching solutions, in particular to a copper-molybdenum etching solution for improving etching morphology and a preparation method of the copper-molybdenum etching solution. The main agent at least comprises the following components in percentage by mass: 6.00 to 20.00 percent of hydrogen peroxide, 5.00 to 15.00 percent of organic acid, 0.10 to 1.50 percent of inorganic acid, 3.00 to 15.00 percent of organic alkali, 0 to 0.05 percent of metal inhibitor, 0.50 to 2.00 percent of stabilizer, 0.50 to 5.00 percent of surfactant and the balance of deionized water; the inorganic acid at least comprises phosphoric acid, and the surfactant at least comprises one of fatty alcohol-polyoxyethylene ether or polyethylene glycol; through the synergistic effect of the phosphoric acid and the surfactant, the roughness of an etched surface can be effectively reduced, lateral etching is reduced, the uniformity and accuracy of etching are improved, and the etching life is prolonged.

Description

Technical Field

[0001] This invention relates to the field of copper-molybdenum etching solution technology, specifically to a copper-molybdenum etching solution for improving etching morphology and its preparation method. Background Technology

[0002] Copper-molybdenum etching solutions often suffer from uneven etching, high surface roughness, and severe lateral etching during the etching process, resulting in poor etched morphology. These problems not only affect circuit performance but can also lead to short circuits, open circuits, and other faults, reducing product yield and production efficiency. Chinese Patent (authorization announcement number CN114875406B) discloses a copper-molybdenum metal etching solution composition and its preparation method. This method mainly solves the health and environmental problems associated with existing copper-molybdenum etching solutions by using a combination of hydrogen peroxide, organic acids, ethylene glycol, and electrochemical inhibitors in the copper-molybdenum etching solution. It improves the copper ion loading capacity and etching morphology quality of the etching solution, achieving low molybdenum residue and high-efficiency etching. However, it still cannot meet the high-precision and high-resolution application requirements of advanced integrated circuit manufacturing and high-density interconnects. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a copper-molybdenum etching solution that improves etching morphology. Through the synergistic effect of phosphoric acid and surfactants, it can effectively reduce the roughness of the etched surface, reduce lateral etching, improve the uniformity and accuracy of etching, and extend the etching life.

[0004] This invention provides a copper-molybdenum etching solution for improving etching morphology, comprising a main agent and auxiliary agents; by mass percentage, the main agent comprises at least: 6.00-20.00% hydrogen peroxide, 5.00-15.00% organic acid, 0.10-1.50% inorganic acid, 3.00-15.00% organic base, 0-0.05% metal inhibitor, 0.50-2.00% stabilizer, 0.50-5.00% surfactant, with deionized water to make up the balance; the inorganic acid comprises at least phosphoric acid, and the surfactant comprises at least one of fatty alcohol polyoxyethylene ether or polyethylene glycol; the auxiliary agents comprise at least auxiliary organic acid, auxiliary organic base, auxiliary inhibitor, auxiliary stabilizer, auxiliary surfactant, and deionized water.

[0005] In one embodiment, the main agent comprises, by mass percentage, at least: 10.00-14.00% hydrogen peroxide, 8.00-10.10% organic acid, 0.40-0.80% inorganic acid, 7.00-9.00% organic base, 0-0.015% metal inhibitor, 1.10-1.40% stabilizer, 1.00-2.00% surfactant, and deionized water to make up the balance.

[0006] In one embodiment, the excipients, by mass percentage, comprise at least 20.00-30.00% auxiliary organic acid, 10.00-25.00% auxiliary organic base, 0.005-0.05% auxiliary inhibitor, 0.80-2.00% auxiliary stabilizer, 0.50-3.00% auxiliary surfactant, with deionized water to make up the balance.

[0007] In one embodiment, the excipients, by mass percentage, comprise at least 26.80% excipient organic acid, 18.00% excipient organic base, 0.01% excipient inhibitor, 1.20% excipient stabilizer, 1.00-2.00% excipient surfactant, with deionized water to make up the balance.

[0008] In one embodiment, the surfactant is a combination of fatty alcohol polyoxyethylene ether and polyethylene glycol, wherein the mass ratio of fatty alcohol polyoxyethylene ether to polyethylene glycol is (0.3-1):(0.3-1).

[0009] In one embodiment, the auxiliary surfactant includes at least one of fatty alcohol polyoxyethylene ether or polyethylene glycol.

[0010] In one embodiment, the auxiliary surfactant is a combination of fatty alcohol polyoxyethylene ether and polyethylene glycol, wherein the mass ratio of fatty alcohol polyoxyethylene ether to polyethylene glycol is (0.3-1):(0.3-1).

[0011] In one embodiment, the organic acid and the auxiliary organic acid are both selected from at least one of acetic acid, oxalic acid, malonic acid, glycolic acid, citric acid, malic acid, valeric acid, tartaric acid, salicylic acid, succinic acid, glutamic acid, or hydroxyethyl sulfonic acid.

[0012] In one embodiment, the organic acid is selected from at least two of malonic acid, salicylic acid, malic acid, or citric acid.

[0013] In one embodiment, the organic acid includes malonic acid, malic acid, and citric acid.

[0014] In one embodiment, the mass ratio of malonic acid, malic acid and citric acid is (1-2):1:(5-10).

[0015] In one embodiment, the mass ratio of malonic acid, malic acid, and citric acid is 1.5:1:7.

[0016] In one embodiment, the auxiliary organic acid includes malonic acid, salicylic acid, malic acid, and citric acid.

[0017] In one embodiment, the mass ratio of malonic acid, salicylic acid, malic acid and citric acid is (1-2):0.1:0.2:(20-30).

[0018] In one embodiment, the mass ratio of malonic acid, salicylic acid, malic acid and citric acid is 1.5:0.1:0.2:25.

[0019] This invention optimizes the selection of organic acids and introduces phosphoric acid, fatty alcohol polyoxyethylene ether, and / or polyethylene glycol to significantly reduce the roughness of the etched surface while avoiding the accumulation or absence of etching solution in local areas, resulting in a smoother etched surface and improved etching uniformity.

[0020] In one embodiment, the organic base and the auxiliary organic base are both selected from at least one of triethylenediamine, diethylaminopropylamine, propylenediamine, triethanolamine, diethanolamine, dimethylethanolamine, isopropanolamine, tris(hydroxymethyl)aminomethane, isobutanolamine, triethylamine, or triethanolamine.

[0021] In one embodiment, the organic base is selected from at least one of isopropanolamine or dimethylethanolamine.

[0022] In one embodiment, the organic base is a combination of isopropanolamine and dimethylethanolamine, wherein the mass ratio of isopropanolamine to dimethylethanolamine is (3-4):(5-6).

[0023] In one embodiment, the auxiliary organic base is isopropanolamine.

[0024] In one embodiment, the metal inhibitor and the co-inhibitor are both selected from at least one of 2-(substituted thio)furan, alloxan, 5-(thiophen-2-yl)-1H-tetrazole, methylpiperazine, hydroxyethylpiperazine, benzotriazole, 3-aminotriazole, 5-methylbenzotriazole, 5-aminotetrazole or methyltetrazole.

[0025] In one embodiment, the stabilizer and the auxiliary stabilizer are both selected from at least one of phenylurea, p-hydroxybenzenesulfonic acid, glycerol, propylene glycol, ethylene glycol, ethylene glycol monobutyl ether, or diethylene glycol.

[0026] In one embodiment, the stabilizer is a combination of phenylurea and 1,2-propanediol, wherein the mass ratio of phenylurea to 1,2-propanediol is (0.4-0.7):(0.5-1).

[0027] In one embodiment, the auxiliary stabilizer is a combination of phenylurea and 1,2-propanediol, wherein the mass ratio of phenylurea to 1,2-propanediol is (0.5-0.7):(0.7-1).

[0028] Furthermore, this invention improves the etching effect and enhances the stability of the etching solution by optimizing the selection and combination of organic bases / auxiliary organic bases, metal inhibitors / auxiliary inhibitors, and stabilizers / auxiliary stabilizers in the system.

[0029] This invention provides a suitable etching rate through the combination of a superior main agent and an auxiliary agent, optimizes the etching angle and morphology, improves etching quality, promotes the uniformity and consistency of etching, reduces the influence of metal ions, and helps extend the service life of the etching solution.

[0030] The copper-molybdenum etching solution provided by this invention improves the etching morphology while maintaining a low CD-loss (linewidth loss, single-sided), a taper angle of 38-42°, and a maximum copper load of 14,000 ppm, meeting the high precision and high resolution application requirements of advanced integrated circuit manufacturing, high-density interconnects, and other applications.

[0031] Another aspect of the present invention provides a method for preparing a copper-molybdenum etching solution with improved etching morphology, comprising at least the following steps: mixing the raw materials of the main agent to prepare the main agent, and mixing the raw materials for preparing the auxiliary agent to prepare the auxiliary agent.

[0032] The method of using the copper-molybdenum etching solution to improve the etching morphology is as follows: use the main agent to etch the metal film layer. During the etching process, for every 1000 ppm increase in copper ions, add 1.50% of the weight of the main agent as an auxiliary agent to the system. Control the etching temperature and the etching is complete.

[0033] Beneficial effects

[0034] 1. This invention provides a copper-molybdenum etching solution that improves etching morphology. Through the synergistic effect of phosphoric acid and surfactant, it can effectively reduce the roughness of the etched surface, reduce lateral etching, improve the uniformity and accuracy of etching, and extend the etching life.

[0035] 2. By optimizing the selection of organic acids and introducing phosphoric acid, fatty alcohol polyoxyethylene ether and / or polyethylene glycol, this invention significantly reduces the roughness of the etched surface while avoiding the accumulation or absence of etching solution in local areas, making the etched surface smoother and improving the uniformity of etching.

[0036] 3. This invention improves the etching effect and enhances the stability of the etching solution by optimizing the selection and combination of organic base / auxiliary organic base, metal inhibitor / auxiliary inhibitor, and stabilizer / auxiliary stabilizer in the system.

[0037] 4. This invention provides a suitable etching rate through the combination of a superior main agent and an auxiliary agent, optimizes the etching angle and morphology, improves etching quality, promotes the uniformity and consistency of etching, reduces the influence of metal ions, and helps to extend the service life of the etching solution.

[0038] 5. The copper-molybdenum etching solution provided by this invention improves the etching morphology while maintaining the CD-loss (linewidth loss, single-sided) at a low level, with a slope angle of 38-42° and a maximum copper load of 14000ppm, meeting the high precision and high resolution application requirements of advanced integrated circuit manufacturing, high-density interconnection, and other applications. Attached Figure Description

[0039] Figure 1 The image shows the SEM characterization of the Cu-Mo / MTD film after etching with the copper-molybdenum etching solution provided in Example 1.

[0040] Figure 2 The image shows the SEM characterization of the Cu-Mo / MTD film after etching with the copper-molybdenum etching solution provided in Example 2.

[0041] Figure 3 SEM characterization image of Cu-Mo / MTD film after etching with copper-molybdenum etching solution provided in Comparative Example 1.

[0042] Figure 4 SEM characterization image of Cu-Mo / MTD film after etching with copper-molybdenum etching solution provided in Comparative Example 2.

[0043] Figure 5 SEM characterization image of Cu-Mo / MTD film after etching with copper-molybdenum etching solution provided in Comparative Example 3.

[0044] Figure 6 SEM characterization image of Cu-Mo / MTD film after etching with copper-molybdenum etching solution provided in Comparative Example 4. Detailed Implementation

[0045] Examples 1-6, Comparative Examples 1-4

[0046] Examples 1-6 and Comparative Examples 1-4 of the present invention provide a copper-molybdenum etching solution for improving etching morphology, comprising a main agent and an auxiliary agent, the formulations of which are shown in Table 1 by mass percentage.

[0047] Table 1

[0048]

[0049]

[0050]

[0051] Examples 1-6 and Comparative Examples 1-4 of the present invention provide a method for preparing a copper-molybdenum etching solution with improved etching morphology, comprising the following steps: mixing the raw materials of the main agent to prepare the main agent, and mixing the raw materials for preparing the auxiliary agent to prepare the auxiliary agent.

[0052] The method of using the copper-molybdenum etching solution to improve the etching morphology is as follows: use the main agent to etch the metal film layer. During the etching process, for every 1000 ppm increase in copper ions, add 1.50% of the weight of the main agent as an auxiliary agent to the system. Control the etching temperature and the etching is complete.

[0053] Performance testing

[0054] 1. Etching Performance Evaluation: The etching compositions provided in the examples and comparative examples were used to etch Cu-Mo / MTD (copper-molybdenum / molybdenum-nickel-titanium alloy) films. The etching conditions are shown in Table 2. After etching, the etching performance was confirmed using SEM analysis equipment. The results are shown in Table 3. Figure 1-6 .

[0055] 2. Maximum copper ion load (ppm): Starting from a copper ion concentration of 500ppm, the standard is to confirm a change of more than 10% in CD-loss (linewidth loss). The results are shown in Table 3.

[0056] Table 2

[0057]

[0058] Table 3

[0059]

[0060] Based on the data in Table 3 and Figure 1-6 It can be seen that, compared with Comparative Examples 1-4, the copper-molybdenum etching solutions provided in Examples 1-6 with improved etching morphology have better etching effects and better meet the needs of practical applications.

Claims

1. A copper-molybdenum etching solution for improving etching morphology, characterized in that, Includes main agent and excipients; By mass percentage, the main agent comprises at least: 6.00-20.00% hydrogen peroxide, 5.00-15.00% organic acid, 0.10-1.50% inorganic acid, 3.00-15.00% organic base, 0-0.05% metal inhibitor, 0.50-2.00% stabilizer, 0.50-5.00% surfactant, and deionized water to make up the balance; the inorganic acid includes at least phosphoric acid, and the surfactant includes at least one of fatty alcohol polyoxyethylene ether or polyethylene glycol; the excipients include at least auxiliary organic acid, auxiliary organic base, auxiliary inhibitor, auxiliary stabilizer, auxiliary surfactant, and deionized water.

2. The copper-molybdenum etching solution for improving etching morphology according to claim 1, characterized in that, The excipients, by mass percentage, include at least 20.00-30.00% auxiliary organic acid, 10.00-25.00% auxiliary organic base, 0.005-0.05% auxiliary inhibitor, 0.80-2.00% auxiliary stabilizer, 0.50-3.00% auxiliary surfactant, and deionized water to make up the balance.

3. The copper-molybdenum etching solution for improving etching morphology according to claim 1, characterized in that, The organic acid and auxiliary organic acid are each selected from at least one of acetic acid, oxalic acid, malonic acid, glycolic acid, citric acid, malic acid, valeric acid, tartaric acid, salicylic acid, succinic acid, glutamic acid, or hydroxyethyl sulfonic acid.

4. The copper-molybdenum etching solution for improving etching morphology according to claim 3, characterized in that, The organic acid is selected from at least two of malonic acid, salicylic acid, malic acid, or citric acid.

5. The copper-molybdenum etching solution for improving etching morphology according to claim 3, characterized in that, The auxiliary organic acids include malonic acid, salicylic acid, malic acid, and citric acid.

6. The copper-molybdenum etching solution for improving etching morphology according to claim 1, characterized in that, The organic base and auxiliary organic base are both selected from at least one of triethylenediamine, diethylaminopropylamine, propylenediamine, triethanolamine, diethanolamine, dimethylethanolamine, isopropanolamine, tris(hydroxymethyl)aminomethane, isobutanolamine, triethylamine, or triethanolamine.

7. The copper-molybdenum etching solution for improving etching morphology according to claim 1, characterized in that, The metal inhibitor and the co-inhibitor are both selected from at least one of 2-(substituted thio)furan, alloxan, 5-(thien-2-yl)-1H-tetrazole, methylpiperazine, hydroxyethylpiperazine, benzotriazole, 3-aminotriazole, 5-methylbenzotriazole, 5-aminotetrazole or methyltetrazole.

8. The copper-molybdenum etching solution for improving etching morphology according to claim 1, characterized in that, The stabilizer and auxiliary stabilizer are selected from at least one of phenylurea, p-hydroxybenzenesulfonic acid, glycerol, propylene glycol, ethylene glycol, ethylene glycol monobutyl ether, or diethylene glycol.

9. The copper-molybdenum etching solution for improving etching morphology according to claim 8, characterized in that, The stabilizer is a combination of phenylurea and 1,2-propanediol.

10. A method for preparing a copper-molybdenum etching solution for improving etching morphology according to any one of claims 1-9, characterized in that, At least the following steps are included: The raw materials for the main agent are mixed to prepare the main agent, and the raw materials for the preparation of the excipients are mixed to prepare the excipients.

Images