A semiconductor chip cleaning solution containing amino acids, preparation method and use thereof

Abstract

The present invention relates to a semiconductor chip cleaning solution containing amino acids, which comprises the following components, calculated by weight: 1-15 parts of inorganic base; 30-50 parts of sulfoxide; 10-20 parts of thiol-containing proline; 5-15 parts of amino acids and their derivatives; 10-20 parts of alcohol amines; and 30-60 parts of ultrapure water. The present invention also discloses a preparation method and use of the above-mentioned cleaning solution. The thiol-containing proline of the present invention has a unique torsion angle structure, which can be cross-linked and constrained to form a cross-linked constrained peptide, and this structure is highly stable in aqueous solution. The constrained peptide can wrap the alkaline molecules and slowly release them as time increases to extend the life of the cleaning solution. The thiol group of the constrained peptide is also complexed with copper to form a passivation film copper layer protection, and the passivation film can be directly washed by water. The amino acid group of the alcohol amine can also form a constrained peptide with the thiol-containing proline to promote the extension of the life of the cleaning solution.

Description

Technical Field

[0001] The invention belongs to the field of semiconductor manufacturing technology, and in particular relates to a semiconductor chip cleaning liquid containing amino acids, a preparation method and application thereof. Background Art

[0002] In the process of semiconductor component manufacturing, the coating, exposure and imaging of the photoresist layer are necessary process steps for the pattern manufacturing of the components. At the end of patterning, that is, after the coating, imaging, ion implantation and etching of the photoresist layer, before the next process step, the photoresist layer material needs to be completely removed. However, since the ion bombardment in the doping step will harden the polymer of the photoresist layer, the photoresist layer becomes less soluble and thus more difficult to remove.

[0003] At present, the semiconductor manufacturing industry generally uses a two-step method, namely dry ashing and wet etching, to remove the photoresist layer, including: the first step of using dry ashing to remove most of the photoresist layer (PR); the second step of using a corrosion inhibitor composition wet etching / cleaning process to remove the remaining photoresist layer, and the specific steps are generally: cleaning liquid cleaning / rinsing / deionized water rinsing. In this process, only the residual polymer photoresist layer and inorganic substances can be removed, and the metal layer cannot be corroded and damaged.

[0004] As the size of semiconductor processes becomes smaller and smaller, high-speed rotary single-wafer cleaning is increasingly used as a cleaning method. Therefore, the corrosion control of metal and non-metallic materials is becoming more and more stringent. It is an urgent problem to develop a cleaning fluid that can be used for batch immersion and batch rotary spray cleaning methods, especially for high-speed single-wafer rotary cleaning methods.

[0005] Typical cleaning solutions in the prior art include: amine cleaning solutions, semi-aqueous amine-based (non-hydroxylamine) cleaning solutions, and fluoride cleaning solutions. Among them, the first two types of cleaning solutions are mainly used in the cleaning process of metal aluminum wires. The cleaning solutions need to be cleaned at high temperatures, generally between 60°C and 80°C, and there is a problem of high corrosion rate to metals. Although existing fluoride cleaning solutions can be cleaned at lower temperatures (room temperature to 50°C), they still have various disadvantages.

[0006] As mentioned above, it is not possible to control the corrosion of metal and non-metal substrates at the same time, and the channel feature size is easily changed after cleaning, thereby changing the semiconductor structure; using traditional benzotriazole as a corrosion inhibitor for metal copper, although the etching rate of metal copper is relatively low, the traditional azole corrosion inhibitor (BTA) is not only difficult to degrade and is not environmentally friendly to the biological system, but also easily adsorbed on the copper surface after cleaning, resulting in contamination of the integrated circuit, which may cause unforeseen conductive failures in the circuit; some existing technologies avoid traditional azoles and use inhibitors that can control copper corrosion and surface adsorption, but there is a problem of high viscosity and surface tension and unsatisfactory cleaning effect.

[0007] Therefore, in order to overcome the defects of existing cleaning solutions and adapt to new cleaning requirements, it is urgent to seek new semiconductor chip cleaning solutions. Summary of the invention

[0008] Technical problem solved by the present invention: The semiconductor chip cleaning liquid of the present invention has strong cleaning ability, can effectively remove photoresist in the semiconductor manufacturing process, and has a lower corrosion rate on copper and the like in high-speed single-chip computer cleaning, effectively solving the problem that traditional corrosion inhibitors cannot well inhibit metal surface corrosion, and the problem that ordinary cleaning liquids have a short storage life.

[0009] In view of the technical problems existing in the prior art, the present invention designs a semiconductor chip cleaning solution containing amino acids, a preparation method and use thereof.

[0010] In order to solve the above-mentioned technical problems, the present invention adopts the following solutions:

[0011] A semiconductor chip cleaning solution containing amino acids, characterized in that it comprises the following components calculated by weight:

[0012]

[0013] Wherein, the mercapto-containing proline is one or more of 4-mercaptoproline, 1-((2S)-2-methyl-3-mercapto-1-oxopropyl)-L-proline, and N-3-acetylmercapto-2-methylpropionyl-L-proline;

[0014] The amino acid and its derivatives are one or more of tryptophan, serine, tyrosine, methionine, asparagine, glutamine, threonine, lysine and arginine;

[0015] The alcohol amine is an alcohol amine containing amino acids.

[0016] Furthermore, the inorganic base is one of potassium hydroxide, sodium hydroxide, lithium hydroxide, barium hydroxide, magnesium hydroxide, and cesium hydroxide;

[0017] The sulfoxide is one or more of dimethyl sulfoxide, diethyl sulfoxide, dibutyl sulfoxide, sulfoxide sulfoxide and tetramethylene sulfoxide.

[0018] Furthermore, the alcoholamine is one or more of rac-threonine-3-nonylamine-2-ol, rac-threonine-3-dodecan-2-ol, rac-threonine-3-hexane-2-ol, and rac-threonine-3-tetradecane-2-ol.

[0019] Furthermore, the mercaptoproline is 4-mercaptoproline.

[0020] Furthermore, the alcoholamine is rac-threonine-3-nonylamine-2-ol.

[0021] Furthermore, the sulfoxide is sulfoxide sulfoxide.

[0022] Furthermore, the inorganic strong base is cesium hydroxide.

[0023] The present invention also discloses a method for preparing a semiconductor chip cleaning solution containing amino acids, which is characterized by comprising the following steps:

[0024] Step 1: dissolving a corresponding amount of inorganic alkali in ultrapure water and stirring evenly to prepare an alkali solution A;

[0025] Step 2: dissolving mercapto-containing proline, amino acids and their derivatives, and alcoholamine in sulfoxide according to weight ratio, and mixing them evenly to obtain a mixed solution B;

[0026] Step 3: Add the alkaline solution A prepared in step 1 to the mixed solution B prepared in step 2, mix well, and stir at room temperature to obtain the cleaning solution containing amino acids.

[0027] The present invention also discloses a cleaning method for a semiconductor chip cleaning solution containing amino acids, which is characterized by comprising the following steps:

[0028] Step 1: diluting the amino acid-containing semiconductor chip cleaning solution with ultrapure water by 3-10 times, preferably 3-5 times; then soaking the semiconductor wafer with the amino acid cleaning solution aqueous solution at 30-50° C. for 15-30 minutes to obtain a soaked semiconductor wafer;

[0029] Step 2: Rinse the soaked semiconductor wafer twice in ultrapure water to complete the cleaning process of the semiconductor wafer.

[0030] The invention also discloses a use of the amino acid-containing semiconductor chip cleaning solution in semiconductor wafer cleaning.

[0031] In the present invention, in order to achieve better cleaning liquid performance, the inorganic base can be preferably 5-15 parts; the sulfoxide can be preferably 35-45 parts; the thiol-containing proline can be preferably 12-18 parts; the amino acid and its derivatives can be preferably 10-15 parts; the alcohol amine can be preferably 15-20 parts; and the ultrapure water can be preferably 30-50 parts.

[0032] In the present invention, the thiol-containing proline has a unique torsion angle structure and can be used as a cross-linking agent. The disulfide bonds it carries can be cross-linked and constrained with amino acids to form a new cross-linked constrained peptide. This structure is highly stable in aqueous solution. The constrained peptide can wrap the inorganic base molecules and play a role in sustained release, slowly releasing the inorganic base to extend the storage life of the cleaning solution.

[0033] In the present invention, the alkalinity of cesium hydroxide is stronger, so that the cleaning effect of the cleaning solution is better: OH - The increased content can better dissolve and strip the photoresist.

[0034] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising" and similar meanings, and closed-ended "consisting of..." and similar meanings.

[0035] The present invention provides a semiconductor chip cleaning solution containing amino acids, and its preparation method and use have the following beneficial effects:

[0036] (1) The thiol-containing proline in the present invention has a unique twisted angle structure, and the disulfide bonds it carries can be cross-linked and constrained with amino acids and their derivatives to form new cross-linked constrained peptides. This structure is highly stable in aqueous solution and can wrap inorganic base molecules and slowly release them over time, thereby extending the storage life of the cleaning solution.

[0037] (2) The thiol groups on the constrained peptide formed by the thiol-containing proline and amino acids and their derivatives in the present invention will also complex with copper to form a passivation film to protect the copper layer below the copper. The passivation film can be directly washed with pure water and will not be adsorbed on the copper surface, thereby avoiding affecting subsequent processes.

[0038] (3) The amino acid groups in the alcohol amine of the present invention can also form a constrained peptide with the mercapto-containing proline to encapsulate the inorganic base molecules and slowly release them over time, thereby promoting the extension of the storage life.

[0039] (4) The cleaning solution of the present invention is environmentally friendly, pollution-free, and has low volatile loss. After cleaning, the chip does not need to be rinsed with acetone, but only needs to be rinsed with pure water, which is harmless to the environment and human body. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 : A surface microscope picture of a semiconductor wafer magnified 50 times after cleaning using the amino acid-containing cleaning solution of Example 1 of the present invention after being placed for 85 days;

[0041] Figure 2 : This is a surface microscope picture magnified 50 times of a semiconductor wafer cleaned by the cleaning solution of Comparative Example 1 of the present invention after being placed for 85 days. DETAILED DESCRIPTION

[0042] The present invention will be further described below in conjunction with specific embodiments and accompanying drawings:

[0043] Table 1 Examples 1-8

[0044]

[0045]

[0046] Table 2 Comparative Examples 1-4

[0047]

[0048] Table 3 Test results

[0049]

[0050]

[0051] Regarding the preparation method of the semiconductor chip cleaning solution containing amino acids of the present invention:

[0052] The following steps are involved:

[0053] Step 1: dissolving a corresponding amount of inorganic alkali in ultrapure water and stirring evenly to prepare an alkali solution A;

[0054] Step 2: dissolving mercapto-containing proline, amino acids and their derivatives, and alcoholamine in sulfoxide according to weight ratio, and mixing them evenly to obtain a mixed solution B;

[0055] Step 3: Add the alkaline solution A prepared in step 1 to the mixed solution B prepared in step 2, mix well, and stir at room temperature to obtain a semiconductor chip cleaning solution containing amino acids.

[0056] About the cleaning method of the semiconductor chip cleaning solution containing amino acid of the present invention

[0057] The following steps are involved:

[0058] Wherein, Examples 1-3 are cleaned according to the following method:

[0059] Step 1: diluting the amino acid-containing semiconductor chip cleaning solution with ultrapure water by 3 times, and then soaking a semiconductor wafer with the amino acid cleaning solution aqueous solution at 40° C. for 20 minutes to obtain a soaked semiconductor wafer;

[0060] Step 2: Rinse the soaked semiconductor wafer twice in ultrapure water to complete the cleaning process of the semiconductor wafer.

[0061] Wherein, embodiment 4-5 is cleaned according to the following method:

[0062] Step 1: diluting the amino acid-containing semiconductor chip cleaning solution with ultrapure water by 5 times, and then soaking a semiconductor wafer with the amino acid cleaning solution aqueous solution at 30° C. for 30 minutes to obtain a soaked semiconductor wafer;

[0063] Step 2: Rinse the soaked semiconductor wafer twice in ultrapure water to complete the cleaning process of the semiconductor wafer.

[0064] Wherein, Examples 6-8 are cleaned according to the following method:

[0065] Step 1: diluting the amino acid-containing semiconductor chip cleaning solution with ultrapure water by 10 times, and then soaking a semiconductor wafer with the amino acid cleaning solution aqueous solution at 50° C. for 15 minutes to obtain a soaked semiconductor wafer;

[0066] Step 2: Rinse the soaked semiconductor wafer twice in ultrapure water to complete the cleaning process of the semiconductor wafer.

[0067] The cleaning method in the comparative example is the same as that in Example 1.

[0068] About performance testing and description:

[0069] 1. The storage life test method is as follows:

[0070] The cleaning ability of the cleaning solution for chip photoresist was examined after initial preparation and storage in the dark at room temperature for 85 days. There was no obvious deterioration in the cleaning effect, indicating that the cleaning solution has a long storage life.

[0071] The specific method is as follows: first, dilute the cleaning solution 3 times with ultrapure water, then directly immerse the semiconductor chip with photoresist to be cleaned in the cleaning solution at 40°C for 25 minutes, then rinse with ultrapure water (resistance at least 18MΩ at 25°C), and finally blow dry the chip with high-purity nitrogen (volume purity greater than 99.999%) to complete the cleaning of the photoresist. Use a microscope to observe the photoresist cleaning effect of the chip.

[0072] 2. The copper corrosion rate test method is as follows:

[0073] ICP-MS (Inductively Coupled Plasma Mass Spectrometry) was used to accurately and quantitatively test the corrosion of metal copper. The specific test method is as follows: a Si wafer with a size of 4×4 cm and a copper-plated surface was immersed in a cleaning solution at 40°C for 30 minutes, and then the metal ion concentration in the cleaning solution was measured by ICP-MS, and the corrosion rate ( / min, that is / minute, also known as "etching rate"), thereby obtaining the corrosion rate of the cleaning solution on the metal copper.

[0074] Analysis of the test results:

[0075] It can be seen from the test results in Table 3 that, firstly, the amino acid-containing semiconductor chip cleaning solution prepared in the embodiment of the present invention has no obvious deterioration in photoresist cleaning effect after being placed for 85 days, indicating that the cleaning solution of the present invention has a good storage life and is more suitable for long-distance transportation and storage.

[0076] Second, the cleaning solution prepared in the embodiment of the present invention has a corrosion rate on metallic copper less than / min, which proves that the cleaning solution of the present invention has higher corrosion resistance to the metal copper layer.

[0077] Third, the cleaning effect of the cleaning solution of the embodiment of the present invention is still good after 85 days of storage, the chip surface is still clean, and there is no photoresist residue. However, the cleaning effect of the cleaning solution of the comparative example is poor after 85 days of storage, and there is obvious photoresist residue on the chip surface.

[0078] In Comparative Example 1, no mercapto-containing proline was added, and in Comparative Example 3, mercapto-containing proline was replaced. The corrosion rates of metal copper in Comparative Example 1 and Comparative Example 3 were respectively / min and / min, these two data show that the above two cleaning solutions have poor corrosion resistance to the metal copper layer. At the same time, after the cleaning solutions were placed for 85 days, the cleaning effect became very poor, and photoresist residues were obviously left on the chip surface.

[0079] In Comparative Example 2, other alcohol amine components were selected, and in Comparative Example 4, no amino acid and its derivative components were added. The corrosion rates of the cleaning solutions prepared in Comparative Example 2 and Comparative Example 4 on metallic copper were both greater than / min, which proves that the above two cleaning solutions have poor corrosion resistance to the metal copper layer. At the same time, after the cleaning solutions were placed for 85 days, the cleaning effect became poor, and photoresist residues were found on the chip surface.

[0080] Further comparison and explanation through the attached drawings in the specification :

[0081] Figure 1This is a 50-fold magnified surface microscope image of a semiconductor wafer cleaned with the amino acid-containing cleaning solution of Example 1 of the present invention after being placed for 85 days. Figure 1 It can be seen that after cleaning, the chip surface is clean and there is no photoresist residue.

[0082] Figure 2 This is a 50-fold magnified surface microscope picture of a semiconductor wafer after cleaning using the cleaning solution of Comparative Example 1 of the present invention after being placed for 85 days. Figure 2 It can be seen that there is obvious photoresist residue on the chip.

[0083] The thiol-containing proline in the present invention has a unique torsion angle structure, which can be cross-linked with amino acids and their derivatives to form a new cross-linked constrained peptide. This structure is highly stable in aqueous solution, and the constrained peptide can wrap the alkaline molecules, wrap the alkaline molecules and slowly release them, thereby extending the storage life of the cleaning solution. The thiol group on the constrained peptide will also complex with copper to form a passivation film copper layer protection, and the passivation film can be directly washed with water. The amino acid group of the alcoholamine can also form a constrained peptide with the thiol proline, wrap the alkaline molecules and slowly release them, extending the storage life of the cleaning solution. The cleaning agent of the present invention is environmentally friendly, pollution-free, and has low volatile loss. After cleaning, the chip does not need to be rinsed with acetone, and can be rinsed with pure water, which is harmless to the environment and human body.

[0084] The present invention is described exemplarily above in conjunction with the embodiments and drawings. It is obvious that the implementation of the present invention is not limited to the above-mentioned methods. As long as various improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A semiconductor chip cleaning solution containing amino acids, characterized in that: Calculated by weight, it includes the following components: 1-15 parts of inorganic base; 30-50 parts of sulfoxide; Contains 10-20 parts of mercaptoproline; Amino acids 5-15 parts; 10-20 parts of alcoholamine; 30-60 parts of ultrapure water; Wherein, the mercapto-containing proline is one or two of 4-mercaptoproline and 1-((2S)-2-methyl-3-mercapto-1-oxopropyl)-L-proline; The amino acid is one or more of tryptophan, serine, tyrosine, methionine, asparagine, glutamine, threonine, lysine, and arginine; The inorganic base is one of potassium hydroxide, sodium hydroxide, lithium hydroxide, barium hydroxide, magnesium hydroxide and cesium hydroxide; The sulfoxide is one or more of dimethyl sulfoxide, diethyl sulfoxide, dibutyl sulfoxide, sulfoxide sulfoxide, and tetramethylene sulfoxide; The alcohol amine is rac-threonine-3-nonylamine-2-ol.

2. The amino acid-containing semiconductor chip cleaning solution according to claim 1, characterized in that: The mercapto-containing proline is 4-mercaptoproline.

3. The amino acid-containing semiconductor chip cleaning solution according to claim 1, characterized in that: The sulfoxide is sulfoxide-based sulfoxide.

4. The amino acid-containing semiconductor chip cleaning solution according to claim 1, characterized in that: The inorganic base is cesium hydroxide.

5. A method for preparing an amino acid-containing semiconductor chip cleaning solution according to any one of claims 1 to 4, characterized in that The following steps are involved: Step 1: dissolving a corresponding amount of inorganic base in ultrapure water and stirring evenly to prepare an alkaline solution A; Step 2: dissolving mercapto-containing proline, amino acid, and alcohol amine in sulfoxide according to weight ratio, and mixing them evenly to obtain a mixed solution B; Step 3: Add the alkaline solution A prepared in step 1 to the mixed solution B prepared in step 2, mix them evenly, and stir at room temperature to obtain the amino acid-containing semiconductor chip cleaning solution.

6. A method for cleaning a semiconductor chip using an amino acid-containing cleaning solution according to any one of claims 1 to 4, characterized in that The following steps are involved: Step 1: preparing the amino acid-containing semiconductor chip cleaning solution with ultrapure water into an amino acid cleaning solution aqueous solution with a mass percentage concentration of 40-55%, and then soaking a semiconductor wafer with the amino acid-containing semiconductor chip cleaning solution aqueous solution at 30-50° C. for 15-30 minutes to obtain a soaked semiconductor wafer; Step 2: Rinse the soaked semiconductor wafer in ultrapure water at least twice to complete the cleaning process of the semiconductor wafer.

7. Use of the amino acid-containing semiconductor chip cleaning solution according to any one of claims 1 to 4 in semiconductor wafer cleaning.

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