Semiconductor wafer metal electrode protection liquid, preparation method and use thereof
By using a combination of composite corrosion inhibitors and pH adjusters, the oxidation and corrosion problems of metal electrodes in the semiconductor wafer manufacturing process are solved, efficient protection and cleaning effects are achieved, and the performance and reliability of the device are improved.
Patent Information
- Application Number
- CN202310768833.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-28
- Publication Date
- 2025-08-29
- Estimated Expiration
- 2043-06-28
AI Technical Summary
In the prior art, metal electrodes are susceptible to oxidation and corrosion during the manufacturing process of semiconductor wafers, resulting in reduced performance and reliability, and difficult cleaning, and insufficient stability of the existing protective liquid.
Complex corrosion inhibitors are used, including a combination of homopolymer amino acids and/or amino acid PEG crosslinked polymers and oxime compounds, to form a protective film, combine pH adjusters and wetting agents to prevent corrosion of metal electrodes, and reduce surface tension through alcohols to enhance cleaning effect.
Effectively protect metal electrodes, prevent oxidation and corrosion, and no residue after cleaning, improving the performance and reliability of semiconductor devices.
Smart Images
Figure CN116875983B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to semiconductor wafer technology, and in particular to a semiconductor wafer metal electrode protection liquid, a preparation method and use thereof. Background Art
[0002] Semiconductor wafers are an important component in the manufacture of semiconductor devices, and metal electrodes are one of the important components on semiconductor wafers. During the manufacturing process of semiconductor wafers, metal electrodes need to undergo multiple processing and treatments to ensure their performance and reliability. However, during the processing and treatment process, metal electrodes are easily affected by environmental factors such as oxidation and corrosion, which can lead to a decline in their performance and reliability, or even failure. Therefore, protecting the stability and reliability of metal electrodes is crucial for the manufacture of semiconductor devices. It is urgent to develop a semiconductor wafer metal electrode protection liquid that is suitable for rinsing after photoresist removal from various semiconductor devices, can effectively protect metal electrodes, and is easy to rinse, so as to improve the performance and reliability of semiconductor devices. Summary of the Invention
[0003] The purpose of the present invention is to address the problems of insufficient stability of current metal protection liquids, difficulty in cleaning, and corrosion of metal electrodes, and to propose a semiconductor wafer metal electrode protection liquid. The protection liquid has excellent protection and stability, can be used directly after the wafer is cleaned with a stripping liquid, effectively protects the metal electrodes, improves the performance and reliability of semiconductor devices, and leaves no residue after cleaning.
[0004] To achieve the above object, the technical solution adopted by the present invention is: a semiconductor wafer metal electrode protection solution, comprising the following components in the following weight proportions:
[0005]
[0006]
[0007] Furthermore, the polymer is a homopolymeric amino acid and / or an amino acid PEG cross-linked polymer. Homopolymeric amino acids or amino acid PEG cross-linked polymers have a relatively large number of nitrogen and oxygen atoms in their structures that can form chemical bonds with the Cu and Al surfaces, forming a protective film to prevent the material from being corroded.
[0008] Furthermore, the polyamino acid is one or more of γ-polyglutamic acid, polyornithine, polylysine, polyglycine, polyphenylalanine, polyglutamic acid and polyarginine.
[0009] Furthermore, the amino acid PEG cross-linked polymer is one or more of polylysine cross-linked polyethylene glycol, polyglutamic acid cross-linked polyethylene glycol, polyaspartic acid cross-linked polyethylene glycol and polyphenylalanine cross-linked polyethylene glycol.
[0010] Furthermore, the polymer is preferably polyaspartic acid cross-linked polyethylene glycol.
[0011] Furthermore, the polymer is preferably 1.5-3 parts.
[0012] Furthermore, the oxime compound is one or more of acetone oxime, 1,2-cyclohexanedione dioxime, dimethylglyoxime, salicylaldehyde oxime, acetaldehyde oxime, butanone oxime, glyoxime, butyramide oxime, vanilloid oxime, furfural oxime and propionaldehyde oxime.
[0013] Furthermore, the oxime compound is preferably butanone oxime.
[0014] Furthermore, the oxime compound is preferably 0.3-0.6 parts.
[0015] Furthermore, the mass ratio of the homopolymeric amino acid and / or amino acid PEG cross-linked polymer to the oxime compound is 1-5:1.
[0016] Furthermore, the mass ratio of the homopolymeric amino acid and / or amino acid PEG cross-linked polymer to the oxime compound is preferably 2-4:1.
[0017] Furthermore, the mass ratio of the homopolymeric amino acid and / or amino acid PEG cross-linked polymer to the oxime compound is most preferably 3:1.
[0018] The present invention uses a compound corrosion inhibitor: homopolymeric amino acids and / or amino acid PEG cross-linked polymers and oxime compounds. For example, homopolymeric amino acids and amino acid PEG cross-linked polymer compounds can form chemical bonds on metal substrates, forming a protective film to prevent electrochemical corrosion of metal electrodes such as Cu and Al when in contact with water. At the same time, oxime compounds can reduce the dissolved oxygen in the water, inhibit oxygen in the cleaning solution from oxygen absorption corrosion with the metal electrodes, and further prevent corrosion of metal electrodes such as Cu and Al. The compound corrosion inhibitor can not only protect the metal and substrate from corrosion alone, but also produce a synergistic effect. Homopolymeric amino acids and amino acid PEG cross-linked polymer compounds can form a protective film or adsorb on the metal surface, preventing the metal from contacting oxygen, water and other substances in the environment, thereby slowing down the corrosion rate of the metal. Oxime compounds can quickly reduce the dissolved oxygen in the water, forming an oxide protective film on the surface of the metal electrode to prevent oxidative corrosion, playing a role in corrosion inhibition and passivation on the metal surface; and provide electrons to the homopolymeric amino acids and their PEG cross-linked polymer compounds, causing them to form a more stable protective film on the metal surface, thereby enhancing the protective effect of the corrosion inhibitor. In addition, homopolymeric amino acids and amino acid PEG cross-linked polymer compounds can also enhance the reducing ability of oxime compounds, making them more effective in reducing metal oxidation and significantly improving protection capabilities.
[0019] Furthermore, the mass ratio of the polyaspartic acid cross-linked polyethylene glycol to butanone oxime is 1-5:1.
[0020] Furthermore, the mass ratio of the polyaspartic acid cross-linked polyethylene glycol to butanone oxime is preferably 2-4:1.
[0021] Furthermore, the mass ratio of the polyaspartic acid cross-linked polyethylene glycol to butanone oxime is most preferably 3:1.
[0022] Furthermore, the pH adjuster is one or more of ethanolamine, diethanolamine, triethanolamine, isopropanolamine, N-ethylethanolamine, diglycolamine, AMP-95, succinic acid, citric acid, malic acid, lactic acid, tartaric acid, malonic acid, diglycolic acid, maleic acid, glycolic acid, hydroxybutyric acid, and citric acid. The pH adjuster can prevent the pH value of the wafer with the stripping solution from increasing or decreasing instantaneously when it contacts the protective solution, thereby causing corrosion of the wafer.
[0023] Furthermore, the pH adjuster is preferably diglycolamine and glycolic acid. When diglycolamine and glycolic acid are used together as pH adjusters, the wafer surface will carry some of the cleaning solution into the water when it is removed from the stripping solution or other cleaning solution. The pH value of the wafer surface will change rapidly when the wafer contacts the water, causing corrosion. The addition of the pH adjuster can prevent the sudden change in pH value when the wafer surface contacts the water, thereby preventing corrosion.
[0024] Furthermore, the mass ratio of diglycolamine to glycolic acid is 1:1-4.
[0025] Furthermore, the mass ratio of diglycolamine to glycolic acid is preferably 1:2-4.
[0026] Furthermore, the mass ratio of diglycolamine to glycolic acid is most preferably 1:3.
[0027] Furthermore, the pH value of the semiconductor wafer metal electrode protection solution is 6.5-7.5.
[0028] Furthermore, the pH of the semiconductor wafer metal electrode protection solution is preferably 6.8.
[0029] Furthermore, the pH adjuster is preferably 0.5-3 parts.
[0030] Furthermore, the wetting agent is an alkynol compound.
[0031] Furthermore, the wetting agent is one or more of 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 4,7-dihydroxy-2,4,7,9-tetramethyl-5-decyne, 2,4,7,9-tetramethyl-5-decyne-4,7-diol polyoxyethylene ether, and 2,5,8,11-tetramethyl-6-dodecyne-5,8-diol polyoxyethylene ether. Adding a wetting agent to the semiconductor wafer metal electrode protection solution of the present invention can effectively reduce the surface tension of the metal protection solution, allowing the protection solution to penetrate between chips, increase the contact area between the protection solution and the wafer, and enhance protection and cleaning capabilities.
[0032] Furthermore, the wetting agent is preferably 2,4,7,9-tetramethyl-5-decyne-4,7-diol.
[0033] Furthermore, the wetting agent is preferably 0.5-1 part.
[0034] Furthermore, the alcohol is one or more of methanol, ethanol, isopropanol, n-propanol, butanol, ethylene glycol, propylene glycol, butanediol, glycerol, diethylene glycol, polyethylene glycol, and polypropylene glycol. The addition of the alcohol can reduce the surface tension of the protective solution, increase the wetting effect, and prevent the protective solution from remaining on the wafer surface.
[0035] Furthermore, the wetting agent is preferably isopropyl alcohol and / or diethylene glycol.
[0036] Furthermore, the alcohol is preferably 15-20 parts.
[0037] Furthermore, the deionized water is preferably 70-80 parts.
[0038] Another object of the present invention is to disclose a method for preparing the semiconductor wafer metal electrode protection solution, comprising the following steps:
[0039] Step 1: Add the alcohol compound and wetting agent into the container and stir until the materials are completely mixed and stirred for 1-2 hours;
[0040] Step 2: Add the polymer and water into a container and stir until the solid is completely dissolved, then add the oxime compound and pH adjuster while stirring, and stir for 1-2 hours;
[0041] Step 3: Mix and stir the solutions prepared in step 1 and step 2 for 0.5-1 hour until they are uniform and transparent, thereby obtaining the semiconductor wafer metal electrode protection solution.
[0042] Another object of the present invention is to disclose a use of the semiconductor wafer metal electrode protection liquid in the field of rinsing after photoresist removal in semiconductor wafer manufacturing.
[0043] Another object of the present invention is to disclose a method for rinsing a semiconductor wafer with the metal electrode protection solution, comprising the following steps:
[0044] S1: Rinse the semiconductor wafer after the photoresist is removed in the semiconductor wafer metal electrode protection solution for 1-5 minutes;
[0045] S2: Use nitrogen to blow dry and complete the rinsing process.
[0046] The semiconductor wafer metal electrode protection liquid, its preparation method and use of the present invention have the following advantages compared with the prior art:
[0047] 1. The present invention uses a composite corrosion inhibitor: homopolymeric amino acids and / or amino acid PEG cross-linked polymers and oxime compounds. Homopolymeric amino acids and amino acid PEG cross-linked polymer compounds can form chemical bonds on metal substrates, forming a protective film to prevent electrochemical corrosion of metal electrodes such as Cu and Al when in contact with water. At the same time, oxime compounds can reduce the dissolved oxygen in water, inhibit oxygen in the cleaning solution from oxygen absorption corrosion with the metal electrodes, and further prevent corrosion of metal electrodes such as Cu and Al. The composite corrosion inhibitor can not only protect the metal and substrate from corrosion alone, but also produce a synergistic effect. Homopolymeric amino acids and their PEG cross-linked polymer compounds can form a protective film or adsorb on the metal surface, preventing the metal from contacting oxygen, water and other substances in the environment, thereby slowing the corrosion rate of the metal. Oxime compounds can quickly reduce the dissolved oxygen in water, forming an oxide protective film on the surface of the metal electrode to prevent oxidative corrosion, and play a role in corrosion inhibition and passivation on the metal surface. They also provide electrons to the homopolymeric amino acids and their PEG cross-linked polymer compounds, causing them to form a more stable protective film on the metal surface, thereby enhancing the protective effect of the corrosion inhibitor. In addition, homopolymeric amino acids and amino acid PEG cross-linked polymer compounds can also enhance the reducing ability of oxime compounds, making them more effective in reducing metal oxidation and significantly improving protection capabilities.
[0048] 2. The pH adjuster of the present invention can prevent the pH value of a wafer with a stripping solution from suddenly increasing or decreasing when it comes into contact with a protective solution, potentially causing corrosion. For example, the present invention uses both diglycolamine and glycolic acid as pH adjusters. When a wafer is removed from a stripping solution or other cleaning solution, the surface of the wafer will carry some of the cleaning solution into the water. The pH value of the wafer surface will rapidly change when the wafer contacts the water, causing corrosion. The addition of a pH adjuster can prevent this sudden change in pH value when the wafer surface contacts the water, thus preventing corrosion.
[0049] 3. Adding a wetting agent to the semiconductor wafer metal electrode protection liquid of the present invention can effectively reduce the surface tension of the protection liquid, allowing the protection liquid to penetrate between chips, increase the contact area between the protection liquid and the wafer, and enhance the protection and cleaning capabilities.
[0050] 4. The addition of alcohols in the present invention can reduce the surface tension of the protective liquid and increase the wetting effect. At the same time, alcohols can prevent the protective liquid from remaining on the wafer surface. After using the semiconductor wafer metal electrode protective liquid of the present invention to clean the wafer, there is no need to wash it with water.
[0051] In summary, the metal electrode protection liquid of the present invention can be used as a stripping liquid or other cleaning liquid in the rinsing front-end process, and has a good protective effect on metal electrodes such as Cu and Al, and can effectively inhibit their corrosion. BRIEF DESCRIPTION OF THE DRAWINGS
[0052] Figure 1 This is a microscope picture magnified 100 times after the semiconductor wafer was soaked in Example 1 for 1 hour.
[0053] Figure 2 This is a microscope picture magnified 100 times after the semiconductor wafer was soaked in Comparative Example 1 for 1 hour. DETAILED DESCRIPTION
[0054] The present invention is further described below with reference to the embodiments:
[0055] Example 1
[0056] This embodiment discloses a variety of semiconductor wafer metal electrode protection solutions, the components and weight ratios of which are shown in Table 1.
[0057] The method for preparing the semiconductor wafer metal electrode protection liquid comprises the following steps:
[0058] Step 1: Add the alcohol compound and wetting agent into the container and stir until the materials are completely mixed and stirred for 2 hours;
[0059] Step 2: Add the polymer and water into a container and stir until the solid is completely dissolved, then add the oxime compound and pH adjuster while stirring, and stir for 2 hours;
[0060] Step 3: Mix and stir the solutions prepared in step 1 and step 2 for 1 hour until they are uniform and transparent, thereby obtaining the semiconductor wafer metal electrode protection solution.
[0061] Table 1 Components and weight ratios of semiconductor wafer metal electrode protection solutions of Examples 1-14
[0062]
[0063]
[0064]
[0065] Comparative Examples 1-4
[0066] Comparative Examples 1-4 disclose a variety of metal electrode protection solutions, the components and weight ratios of which are shown in Table 2. The preparation method of the metal electrode protection solution is the same as that of Example 1.
[0067] Table 2 Components and weight ratios of metal electrode protective solutions of Comparative Examples 1-4
[0068]
[0069]
[0070] Performance test and description
[0071] The various properties of the above-mentioned examples or comparative examples were tested below. The test results are shown in Table 3. Examples 1-14 had a low corrosion rate on the Al electrode and were clean after cleaning without any solution residue. Comparative Example 1 did not contain homopolymeric amino acids or amino acid PEG cross-linked polymers. After soaking for 1 hour, the Al electrode was severely corroded. Comparative Example 2 did not contain oxime compounds, and the Al electrode was slightly corroded. Comparative Example 3 did not add a pH adjuster. After mixing with the alkaline stripping solution, the pH value increased, resulting in an increase in the corrosion rate of the Al electrode. Comparative Example 4 did not add a surfactant. After drying with nitrogen, a small amount of water marks remained on the surface.
[0072] Figure 1 This is a microscope picture magnified 100 times after the semiconductor wafer was soaked in Example 1 for 1 hour. Figure 2 This is a 100x microscope image of a semiconductor wafer after being soaked for 1 hour in Comparative Example 1. It can be seen that without the addition of homopolymeric amino acids or amino acid PEG cross-linked polymers, the Al electrode surface is severely corroded.
[0073] Table 3 Performance test results
[0074]
[0075]
[0076] Cleaning and testing method: After soaking a 5×5 cm Al sheet in the stripping solution for 30 minutes, soak it in the metal protection solution of Examples 1-14 and Comparative Examples 1-4 for 5 minutes respectively, take it out and blow it dry with nitrogen, and observe whether there are any water marks on the surface through a metallographic microscope.
[0077] Corrosion rate test method: prepare the test solution according to the ratio of alkaline stripping solution: metal protection solution = 1:100, and use the four-point probe method to test the resistivity of the Al electrode after immersion for 1 hour to test the Al corrosion rate.
[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A semiconductor wafer metal electrode protection solution, characterized in that: The composition comprises the following components in the following weight ratios: 0.1-5 parts of polymer; 0.05-1 part of oxime compound; 0.1-5 parts of pH regulator; Wetting agent 0.1-3 parts; 10-25 parts of alcohol; 60-90 parts of deionized water; The polymer is a homopolymeric amino acid and / or an amino acid PEG cross-linked polymer; The oxime compound is one or more of acetone oxime, 1,2-cyclohexanedione dioxime, dimethylglyoxime, salicylaldehyde oxime, acetaldehyde oxime, butanone oxime, glyoxime, butyramide oxime, vanilloid oxime, furfural oxime and propionaldehyde oxime; The wetting agent is an acetylenic alcohol compound; The pH value of the semiconductor wafer metal electrode protection solution is 6.5-7.
5.
2. The semiconductor wafer metal electrode protection solution according to claim 1, characterized in that: The pH regulator is one or more of ethanolamine, diethanolamine, triethanolamine, isopropanolamine, N-ethylethanolamine, diglycolamine, AMP-95, succinic acid, citric acid, malic acid, lactic acid, tartaric acid, malonic acid, diglycolic acid, maleic acid, glycolic acid, hydroxybutyric acid and citric acid.
3. The semiconductor wafer metal electrode protection solution according to claim 1, characterized in that: The alcohol is one or more of methanol, ethanol, isopropanol, n-propanol, butanol, ethylene glycol, propylene glycol, butanediol, glycerol, diethylene glycol, polyethylene glycol and polypropylene glycol.
4. A method for preparing the semiconductor wafer metal electrode protection solution according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: Add the alcohol compound and wetting agent into the container and stir until the materials are completely mixed and stirred for 1-2 hours; Step 2: Add the polymer and water into a container and stir until the solid is completely dissolved, then add the oxime compound and pH adjuster while stirring, and stir for 1-2 hours; Step 3: Mix and stir the solutions prepared in step 1 and step 2 for 0.5-1 hour until they are uniform and transparent, thereby obtaining the semiconductor wafer metal electrode protection solution.
5. Use of the semiconductor wafer metal electrode protection solution according to any one of claims 1 to 3 in the field of rinsing after photoresist removal in semiconductor wafer manufacturing.
6. A method for rinsing a semiconductor wafer using the metal electrode protection solution according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Rinse the semiconductor wafer after the photoresist is removed in the semiconductor wafer metal electrode protection solution for 1-5 minutes; S2: Use nitrogen to blow dry and complete the rinsing process.