Metal corrosion-resistant cleaning agent, preparation method and application

Abstract

The invention relates to a metal anti-corrosion cleaning agent, a preparation method and application, and the metal anti-corrosion cleaning agent comprises the following components in parts by weight: 0.001-0.06 part of a composite functional agent; 0.1 to 3 parts of a pH regulator; 0.01 to 1 part of inorganic acid; 50-80 parts of an organic solvent; and 20-50 parts of ultrapure water. The thienyl carboxylic ester derivative and the alkanol derivative are combined, the thienyl carboxylic ester derivative removes metal ions (such as Cu < + > and Fe < + >) in a targeted mode by means of the strong chelating capacity of ester groups, and organic pollutants are stripped through the pi-pi effect; the alkanol derivative wraps non-polar residual gum by using a long-chain hydrophobic end, and a hydrophilic end enhances the wettability of a solution, so that full-coverage cleaning of a nano-scale structure is realized.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor manufacturing processes, and particularly relates to a metal corrosion-resistant cleaning agent, its preparation method, and its application. Background Art

[0002] In typical semiconductor manufacturing processes, a photoresist mask is formed on a metal layer. After exposure, a pattern of the conductive metal layer is formed using plasma etching. Because a large amount of halogen-containing gas is used in metal-layer plasma etching, the plasma is excited to etch the metal. Photoresist etched by vapor-phase plasma typically forms a hardened shell on the material surface. This hardened shell is composed of cross-linked organic polymers and may also contain small amounts of silicon or metal atoms, increasing the structural strength of the hardened shell and making it difficult to remove. Etching with halogen-containing gases may deposit halogen atoms within the photoresist shell, which reduces its solubility and increases its resistance to chemical removal.

[0003] Therefore, chemical cleaning agents are needed to remove metal residues after etching. However, existing corrosion inhibitors, due to their limited functionality and the presence of fluoride ions, are prone to metal corrosion during this process, leading to a decrease in wafer yield. Therefore, solving the metal corrosion problem during the cleaning process after semiconductor wafer etching and ashing is urgently needed. Summary of the Invention

[0004] The technical problem solved by this invention is the high metal corrosion rate of current chip cleaning agents.

[0005] In view of the technical problems existing in the prior art, the present invention designs a metal corrosion resist cleaning agent, preparation method and application, which can effectively remove the residue after metal etching and has almost no corrosion to the chip, thus ensuring wafer yield.

[0006] It should be noted that, in this invention, unless otherwise specified, the specific meaning of "comprising" in relation to composition definition and description includes both open-ended meanings such as "comprising," "including," etc., and closed-ended meanings such as "composed of," etc., and similar meanings.

[0007] To solve the aforementioned technical problems, the present invention adopts the following solution:

[0008] [The first technical solution]

[0009] A metal corrosion-resistant cleaning agent, characterized in that, by weight, it comprises the following components:

[0010] 0.001-0.06 parts of compound functional agent;

[0011] pH adjuster 0.1-3 parts;

[0012] Inorganic acid 0.01-1 part;

[0013] 50-80 parts organic solvent;

[0014] 20-50 parts ultrapure water;

[0015] The composite functional agent is a mixture of thiophene derivatives and alkanoic alcohol derivatives.

[0016] Furthermore, the mass ratio of the thiophene derivative to the alkyl alcohol derivative is 1:1 to 10:1.

[0017] Furthermore, the thiophene derivative is a thiophene carboxylic acid ester derivative.

[0018] Further, the thiophene carboxylic acid ester derivative is one or more of the following: methyl 2-thiophene carboxylate, methyl 3-thiophene carboxylate, methyl thiophene[3,4-b]-thiophene-2-carboxylate, methyl thiophene[2,3-B]pyridine-2-carboxylate, methyl 3-amino-5-tert-butyl-2-thiophene carboxylate, methyl 4H-thiophene[3,2-b]pyrrole-5-carboxylate, and dimethyl 3,4-dihydroxythiophene-2,5-dicarboxylate.

[0019] Furthermore, the alkyl alcohol derivative is a long-chain alkyl alcohol derivative with a carbon chain length of 10-20.

[0020] Furthermore, the long-chain alkyl alcohol derivative is one or more of isochetol, dodecyl carbitol, undecyl alcohol, decyltetradecyl alcohol, and 4-decyl-1-tetradecanool.

[0021] Furthermore, the pH adjuster is one or more of ammonium hydroxide, choline hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

[0022] Furthermore, the inorganic acid is one or more of hydrochloric acid, nitric acid, boric acid, and sulfuric acid.

[0023] Furthermore, the organic solvent is one or more of N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, diethylene glycolamine, monoethanolamine, triethanolamine, and propylene glycol.

[0024] In this invention, in order to further optimize the performance of the metal corrosion-resistant cleaning agent, the components can be optimized as follows: 0.001-0.012 parts of composite functional agent; 0.1-0.5 parts of pH adjuster; 0.01-0.05 parts of inorganic acid; 60-70 parts of organic solvent; and 30-40 parts of ultrapure water.

[0025] In this invention, the mass ratio of the thiophene derivative to the alkanoyl derivative is preferably 5:1.

[0026] In this invention, the thiophene derivative is preferably dimethyl 3,4-dihydroxythiophene-2,5-dicarboxylate.

[0027] In this invention, the alkanol derivative is preferably decyltetradecyl alcohol.

[0028] In this invention, the pH adjuster is preferably ammonium hydroxide.

[0029] In this invention, the inorganic acid is preferably boric acid.

[0030] In this invention, the organic solvent is preferably triethanolamine.

[0031] In this invention, the composite functional agent in the metal corrosion-resistant cleaning agent has a unique role:

[0032] Firstly, thiophene derivatives possess strong coordination ability and can selectively chelate metal ions (such as Cu²⁺). + Fe³ + This material effectively removes metal contaminants from wafer surfaces. The thiophene ring, as a conjugated structure, provides π electrons, adsorbing aromatic organic contaminants (such as photoresist residue). The carboxylic acid ester group in the thiophene derivative enhances molecular polarity and improves compatibility with polar solvents; the ester group hydrolysis is controllable (generating carboxylic acid under acidic conditions, enhancing metal adsorption). The preferred 3,4-dihydroxythiophene-2,5-dicarboxylic acid dimethyl ester also possesses a hydroxyl group as a strong coordinating group, capable of chelating metal ions (such as Cu²⁺). + Fe³ + It forms a water-soluble complex, chelates metal ions, and self-assembles into a monolayer on the silicon surface, adjusting the interfacial energy, inhibiting excessive penetration of cleaning agents, and avoiding sidewall damage.

[0033] Secondly, the hydrogen bonds in the structure of alkanoic alcohol derivatives can disrupt the binding force between contaminants (such as photoresist residues, organic films, etc.) and the substrate, reduce the surface tension of the cleaning agent, enhance the wettability of nanoscale trenches, and ensure full coverage of complex structures. Decyltetradecyl alcohol, as a preferred choice, can reduce the surface tension of the solution, ensure full coverage of nanoscale structures, dissolve non-polar residues with its hydrophobic chain, and improve the dispersion stability of contaminants in solution with its hydrophilic end, forming a microemulsion and preventing particle redeposition.

[0034] [Second Technical Solution]

[0035] A method for preparing the above-mentioned metal corrosion-resistant cleaning agent includes the following steps:

[0036] Step 1: Weigh out the respective amounts of each component;

[0037] Step 2: Mix ultrapure water and inorganic acid evenly to obtain mixture one;

[0038] The organic solvent, the composite functional agent, and the pH adjuster are mixed evenly to obtain mixture two.

[0039] Step 3: Mix and stir the first and second mixtures at room temperature until all materials are completely dissolved and stirred until uniform and transparent to obtain the cleaning agent.

[0040] [The third technical solution]

[0041] A method for using the above-mentioned metal corrosion-resistant cleaning agent includes the following steps:

[0042] Step 1: Heat the metal corrosion-resistant cleaning agent to 40-60℃, and then spray the cleaning agent onto the surface of the semiconductor chip for 5-15 minutes to obtain the cleaned semiconductor chip.

[0043] Step 2: Rinse the cleaned semiconductor chip in ultrapure water at least twice, and then dry it with nitrogen gas to complete the cleaning process of the semiconductor chip.

[0044] [Fourth technical solution]

[0045] The use of the aforementioned metal resist cleaning agent in cleaning semiconductor chips.

[0046] This invention provides a metal corrosion-resistant cleaning agent, its preparation method, and its application, which have the following beneficial effects:

[0047] 1. This invention employs a combination of thienyl carboxylic acid ester derivatives and alkanoic acid derivatives. The thienyl carboxylic acid ester derivatives, through the strong chelating ability of their ester groups, target and remove metal ions (such as Cu²⁺). + Fe³ + The cleaning process involves stripping organic contaminants through π-π interactions. Alkyl alcohol derivatives utilize their long-chain hydrophobic ends to encapsulate non-polar residues, while their hydrophilic ends enhance solution wettability, achieving full-coverage cleaning at the nanoscale. The synergistic effect of these two mechanisms enables the removal of targeted contaminants through a dual-mechanism approach, significantly improving cleaning efficiency. Furthermore, the passivation layer of the thiophene carboxylic acid ester derivative and the micellar dispersion effect of the alkyl alcohol derivative inhibit contaminant redeposition, ensuring virtually no residue remains on the wafer surface after cleaning. Attached Figure Description

[0048] Figure 1 This is a scanning electron microscope image of the chip before cleaning, magnified 15,000 times.

[0049] Figure 2 : A scanning electron microscope image of the chip after cleaning using Example 1, magnified 15,000 times;

[0050] Figure 3: This is a scanning electron microscope image of the chip after it was cleaned using Comparative Example 1 and magnified 15,000 times. Detailed Implementation

[0051] The present invention will be further described below with reference to specific embodiments and accompanying drawings:

[0052] In this invention, Examples 1-10 and Comparative Examples 1-5 disclose a variety of cleaning agents, the components and their mass ratios of which are shown in Tables 1 and 2.

[0053] Table 1. Components and proportions of the metal corrosion-resistant cleaning agents used in Examples 1-10

[0054] Table 2. Components and proportions of cleaning agents in Comparative Examples 1-5

[0055] The preparation method of the metal corrosion-resistant cleaning agent of the present invention is as follows:

[0056] Step 1: Weigh out the respective amounts of each component;

[0057] Step 2: Mix ultrapure water and inorganic acid evenly to obtain mixture one;

[0058] The organic solvent, the composite functional agent, and the pH adjuster are mixed evenly to obtain mixture two.

[0059] Step 3: Mix and stir the first and second mixtures at room temperature until all materials are completely dissolved and stirred until uniform and transparent to obtain the cleaning agent.

[0060] The method of using the metal corrosion-resistant cleaning agent of this invention is as follows:

[0061] Step 1: Heat the semiconductor chip cleaning agent to 40-60°C, and then spray the cleaning agent onto the surface of the semiconductor chip for 5-15 minutes to obtain the cleaned semiconductor chip.

[0062] Step 2: Rinse the cleaned semiconductor chip in ultrapure water at least twice, and then dry it with nitrogen gas to complete the cleaning process of the semiconductor chip.

[0063] Regarding performance testing and explanation:

[0064] The test method for performance 1 cleaning effect is as follows:

[0065] After etching, a chip with silicon oxide as a substrate has a large amount of metal-organic polymers and other residues on it. The chip is cleaned using the cleaning agents of the above embodiments and comparative examples of the present invention. The cleaning method includes the following steps:

[0066] Step 1: Heat the cleaning agent to 40°C in a water bath, then place the semiconductor chip into the rotating device of the microcontroller, and spray the heated semiconductor chip cleaning agent onto the semiconductor chip in a rotating manner for 10 minutes to obtain the cleaned semiconductor chip.

[0067] Step 2: Rinse the cleaned semiconductor chip in ultrapure water at least twice, and dry it with nitrogen gas to complete the cleaning process of the semiconductor chip.

[0068] The ultrapure water used in steps 1 and 2 is deionized water with a resistance of at least 18 MΩ.

[0069] The test method for performance 2 metal corrosion is as follows:

[0070] The corrosive properties of different cleaning agents on metals were tested using ICP-MS (inductively coupled plasma mass spectrometry). The specific test method was as follows: 2×2 cm⁻¹ 2 The wafer (copper plated on it) was placed on a microcontroller rotating table, and the cleaning agent was continuously sprayed at 40°C for 10 minutes using a water bath. Then, the concentration of metal ions in the cleaning agent was measured by ICP-MS, and the corrosion rate (Å / min, also known as "etching rate") was calculated. This was to investigate the corrosion rate of metal by different cleaning agents.

[0071] Simultaneously, a four-point probe instrument was used to test the film thickness of the wafer before and after the microcontroller was sprayed, and the corrosion rate of the cleaning agent on the metal was examined at the same time.

[0072] The performance and yield test results of the cleaning agents obtained in Examples 1-10 and Comparative Examples 1-5 are shown in Table 3.

[0073] Table 3 Test Data

[0074] Analysis and explanation of the test results:

[0075] As can be seen from the test data in Table 3, the metal corrosion-resistant cleaning agent of this invention exhibits excellent low metal corrosion rate and cleaning effect. Specifically:

[0076] Compared with Example 1, Comparative Example 1 does not contain thiophene derivatives. Due to the lack of corrosion inhibitor, the corrosion rate of the metal is higher, and there are a lot of residues on the chip surface and the sidewalls of the holes.

[0077] Comparative Example 2 does not contain alkanol derivatives. Due to the lack of synergistic effect with thiophene derivatives, the corrosion rate of the metal chip is higher and the cleaning efficiency is reduced.

[0078] Comparative Example 3 used a combination of thiophene and decyltetradecyl alcohol as a composite functional agent. Because it could not form a passivation layer after cleaning, the corrosion rate of the metal was too high.

[0079] Comparative Example 4 used a combination of 3,4-dihydroxythiophene-2,5-dicarboxylic acid dimethyl ester and n-nonyl alcohol as a composite functional agent. After cleaning, there was excessive surface residue and a high corrosion rate.

[0080] Comparative Example 5 used a combination of 3-thiophene ethanol ester and 4-decyl-1-tetradecaneol as a composite functional agent, and some residues were still present on the metal sidewall and the corrosion rate was relatively high.

[0081] Further comparison can be made using the accompanying diagrams in the instruction manual:

[0082] Figure 1 This is a scanning electron microscope image of the chip before cleaning, magnified 15,000 times. Figure 2 This is a scanning electron microscope image of the chip after it was cleaned using Example 1, magnified 15,000 times. Figure 3 This is a scanning electron microscope image of the chip after it was cleaned using Comparative Example 1 and magnified 15,000 times.

[0083] from Figure 1 It can be seen that before cleaning Figure 1 The chip surface and sidewalls were covered with metal-organic polymer residues. After cleaning with the cleaning agent prepared in Example 1, Figure 2 A large amount of residue on the chip was removed, with almost no residue remaining on the sidewalls; after cleaning with the cleaning agent of Comparative Example 1, Figure 3 Only a portion of the residue on the chip was removed, with a large amount of residue remaining on the chip surface and sidewalls. This demonstrates that the cleaning agent prepared in Example 1 of this invention has excellent cleaning performance.

[0084] The present invention has been described above by way of example with reference to the embodiments and accompanying drawings. Obviously, the implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A metal corrosion-resistant cleaning agent, characterized in that, Based on parts by weight, it includes the following components: 0.001-0.06 parts of compound functional agent; pH adjuster 0.1-3 parts; Inorganic acid 0.01-1 part; 50-80 parts organic solvent; 20-50 parts ultrapure water; The composite functional agent is a mixture of thiophene derivatives and alkanoic alcohol derivatives.

2. The metal corrosion-resistant cleaning agent according to claim 1, characterized in that: The mass ratio of the thiophene derivative to the alkanol derivative is 1:1 to 10:

1.

3. The metal corrosion-resistant cleaning agent according to claim 1 or 2, characterized in that: The thiophene derivative is a thiophene carboxylic acid ester derivative.

4. The metal corrosion-resistant cleaning agent according to claim 3, characterized in that: The thiophene carboxylic acid ester derivative is one or more of the following: methyl 2-thiophene carboxylate, methyl 3-thiophene carboxylate, methyl thiophene[3,4-b]thiophene-2-carboxylate, methyl thiophene[2,3-B]pyridine-2-carboxylate, methyl 3-amino-5-tert-butyl-2-thiophene carboxylate, methyl 4H-thiophene[3,2-b]pyrrole-5-carboxylate, and dimethyl 3,4-dihydroxythiophene-2,5-dicarboxylate.

5. The metal corrosion-resistant cleaning agent according to claim 1 or 2, characterized in that: The alkanol derivatives are long-chain alkyl alcohol derivatives.

6. The metal corrosion-resistant cleaning agent according to claim 5, characterized in that: The long-chain alkyl alcohol derivative is one or more of isochetol, dodecyl carbitol, undecyl alcohol, decyltetradecyl alcohol, and 4-decyl-1-tetradecanool.

7. The metal corrosion-resistant cleaning agent according to claim 1, characterized in that: The pH adjuster is one or more of ammonium hydroxide, choline hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, and benzyltrimethylammonium hydroxide.

8. A method for preparing the metal corrosion-resistant cleaning agent according to any one of claims 1-7, characterized in that... Includes the following steps: Step 1: Weigh out the respective amounts of each component; Step 2: Mix ultrapure water and inorganic acid evenly to obtain mixture one; The organic solvent, the composite functional agent, and the pH adjuster are mixed evenly to obtain mixture two. Step 3: Mix and stir the first and second mixtures at room temperature until all materials are completely dissolved and stirred until uniform and transparent to obtain the cleaning agent.

9. A method of using the metal corrosion-resistant cleaning agent according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Heat the metal corrosion resist cleaning agent to 40-60℃, and then spray the metal corrosion resist cleaning agent onto the surface of the semiconductor chip for 5-15 minutes to obtain the cleaned semiconductor chip. Step 2: Rinse the cleaned semiconductor chip in ultrapure water at least twice, and then dry it with nitrogen gas to complete the cleaning process of the semiconductor chip.

10. The use of the metal resist cleaning agent according to any one of claims 1-7 in cleaning semiconductor chips.

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