Low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process as well as preparation method and application of low-corrosion fluorine-containing cleaning agent
By leveraging the synergistic chemical effects of compound cleaning agents, the high corrosion problem in semiconductor aluminum manufacturing processes was solved, achieving low-corrosion cleaning, improving device performance and yield, and reducing operational risks.
Patent Information
- Application Number
- CN202511603222.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-04
- Publication Date
- 2026-02-06
AI Technical Summary
Existing semiconductor cleaning solutions have high corrosiveness issues in aluminum manufacturing processes, affecting device performance stability and yield. Furthermore, traditional corrosion inhibitors are unstable at high temperatures, posing an explosion risk, resulting in poor cleaning effects or particle residue.
A compound cleaning agent consisting of fluorinated compounds, organic solvents, bipyridine derivatives, and nitrazole compounds reduces the corrosive properties of metals through the synergistic chemical effects of strong anchoring coordination adsorption, hydrophobic shielding, and fluoride ion capture.
It effectively inhibits metal corrosion, improves cleaning effect, reduces particle residue, enhances device performance stability and yield, and reduces operational risks.
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Figure CN121471987A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the field of semiconductor manufacturing process, and particularly relates to a low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process, a preparation method and application thereof. BACKGROUND
[0002] In the process of manufacturing semiconductor components, after the coating, exposure and imaging of photoresist get the required pattern, the residual photoresist needs to be removed before the next process. At present, the semiconductor manufacturing industry generally adopts a two-step method to remove the photoresist, the first step uses dry ashing to remove most of the photoresist, and the second step uses a wet etching / cleaning process containing corrosion inhibitors to remove the remaining photoresist, and the specific steps are generally cleaning liquid cleaning / rinsing / deionized water rinsing. In this process, only the residual polymer photoresist layer and inorganic matter can be removed, and the metal layer cannot be attacked and damaged.
[0003] In modern IC manufacturing process, the reaction product of metal wiring path and notch after dry etching needs to be cleaned by fluorine-based cleaning agent. Especially in the production process of aluminum wire with line width below 0.35 μm, the micro-etching effect of the cleaning agent on the aluminum wire cannot be ignored, which is extremely likely to cause instability of the performance of the key part of the semiconductor. At present, in the field of semiconductor wafer manufacturing, the aluminum wire cleaning liquid generally needs to be operated at a relatively high process temperature of 50-75℃, and there are problems of poor cleaning effect or excessive attack on the substrate. For example, in some traditional aluminum process cleaning processes, although the cleaning liquid can remove part of the photoresist residues, it has a serious corrosion on the aluminum wire, which not only affects the performance stability of the semiconductor device, but also may cause the reduction of product yield.
[0004] In the wafer manufacturing technology above 0.13 μm, the cleaning liquid for the residue after dry etching of aluminum interconnection mainly uses hydroxylamine type cleaning liquid. This kind of cleaning liquid generally contains organic solvent, organic alcohol amine, hydroxylamine, water and corrosion inhibitor and other components. The hydroxylamine type cleaning liquid has the advantage of being able to efficiently remove various difficultly soluble inorganic residues and organic residues. However, its disadvantage is also very obvious, the operating temperature usually needs to be maintained above 65℃, and the hydroxylamine is extremely unstable, which has the risk of explosion at a relatively high operating temperature. At the same time, the relatively high operating temperature accelerates the decomposition of the system components, causing the rapid evaporation of water, which needs to be continuously supplemented with new liquid to maintain the life of the tank liquid. In addition, after the wafer is treated by the hydroxylamine cleaning liquid, IPA or NMP organic solvent needs to be used as an intermediate cleaning medium, and then deionized water needs to be used for rinsing, so as to prevent corrosion of the metal on the wafer surface, which undoubtedly increases the manufacturing cost of the wafer.
[0005] There are also many problems in the partial fluorine-containing cleaning agent. For example, a disclosed post-dry etching cleaning liquid composition contains fluorine compounds, glyoxylic acid, organic acid salts and water, and the preferred solution contains a surfactant but does not contain an organic solvent. Since the cleaning liquid does not contain an organic solvent, the removal effect is not ideal when actually cleaning wafers with heavy organic residue. Moreover, the fluorine-containing cleaning liquid is prone to particle aggregation during the cleaning process or after long-term storage. These aggregated particles are extremely easy to remain on the wafer surface and are difficult to remove, ultimately adversely affecting the electrical performance of the device.
[0006] For another example, some existing cleaning liquids have deficiencies in the use of corrosion inhibitors. Traditional azole corrosion inhibitors have adsorption problems when controlling metal surface corrosion. In semiconductor aluminum process technology, if the aluminum copper is not uniformly distributed, the grain size is too large, or the deposition speed is too fast during the deposition process, it will cause galvanic corrosion of the aluminum wire during rinsing, thereby reducing the yield of semiconductor devices, affecting the performance of the semiconductor, and in severe cases, even causing the entire device to fail.
[0007] In summary, although a variety of cleaning liquid compositions have been disclosed in the current semiconductor cleaning field, there is still an urgent need to develop a low-corrosion fluorine-containing cleaning agent to overcome the strong corrosive problem of existing fluoride cleaning liquids in the actual application of aluminum process. SUMMARY
[0008] The technical problem solved by the present application is that the corrosion inhibition effect of traditional azole inhibitors is highly dependent on the type of metal. Because the coordination constant of the nitrogen atom with Al³ + is low, the adsorption film is loose and easy to fall off, the corrosion inhibition rate is low, and the corrosion of the metal is high.
[0009] To solve the technical problems existing in the prior art, the present application designs a low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process, its preparation method and application. Through the chemical synergy of "strong anchor point + wide coverage" coordination adsorption + hydrophobic shielding + fluorine ion capture of corrosion inhibitors and the functional integration of wide environmental adaptability, the corrosion performance on metal is reduced, and it has significant application potential.
[0010] It should be noted that in the present application, unless otherwise specified, the specific meaning of "including" involved in the composition limitation and description includes both open-ended "including", "containing" and the like, and closed "consisting of" and the like.
[0011] To solve the above-mentioned technical problems, the present application adopts the following scheme:
[0012]
First technical solution
[0013] A low-corrosion fluorine-containing cleaning agent for semiconductor aluminum processing, characterized in that it comprises the following components by weight:
[0014] fluorine-containing compound 5-20 parts;
[0015] organic solvent 40-90 parts;
[0016] bipyridine derivative 0.1-5 parts;
[0017] azole compound 0.1-5 parts;
[0018] The bipyridine derivative is a bipyridine compound with a functional substituent introduced.
[0019] Further, the bipyridine derivative is a bipyridine compound with a hydroxyl group introduced.
[0020] Further, the bipyridine derivative is one or more of 4,4'-dihydroxy-2,2'-bipyridine, 4-hydroxymethyl-4'-methyl-2,2'-bipyridine, 5-hydroxy-2,2'-bipyridine, and 6,6'-dihydroxy-2,2'-bipyridine.
[0021] Further, in the present application, the fluorine-containing compound is a compound capable of providing a fluorine source, which is well known to those skilled in the art, and more preferably, the fluorine-containing compound is one or more of ammonium fluoride, hydrogen fluoride, tetrabutylammonium fluoride, tetramethylammonium fluoride, and ammonium bifluoride.
[0022] Further, the organic solvent is one or more of a sulfoxide, a sulfone, an imidazolidinone, a pyrrolidinone, an imidazolidinone, an amide, and an alcohol ether.
[0023] Further, the sulfoxide is dimethyl sulfoxide or ethyl methyl sulfoxide.
[0024] Further, the sulfone is dimethyl sulfone or sulfolane.
[0025] Further, the imidazolidinone is 2-imidazolidinone or 1,3-dimethyl-2-imidazolidinone.
[0026] Further, the pyrrolidinone is N-methyl pyrrolidinone or N-cyclohexyl pyrrolidinone.
[0027] Further, the imidazolidinone is 1,3-dimethyl-2-imidazolidinone.
[0028] Further, the amide is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-dimethylpropionamide.
[0029] Further, the alcohol ether is one or more of diethylene glycol dimethyl ether, diethylene glycol monobutyl ether and dipropylene glycol monomethyl ether.
[0030] Further, the azole compound is a triazole compound containing a methyl group.
[0031] Further, the azole compound is one or more of methylbenzotriazole, 1-methyl-1,2,4-triazole, 1-methyl-1,2,3-triazole, 3-methyl-1H-1,2,4-triazole, 1,4-dimethyl-1H-1,2,3-triazole and 4-methyl-1H-1,2,3-triazole.
[0032] In the present application, in order to further optimize the performance of the fluorine-containing cleaning agent, the components can be preferably selected as follows: the fluorine-containing compound 5-10 parts; the organic solvent 60-90 parts; the bipyridine derivative 0.3-3 parts; the azole compound 0.3-3 parts.
[0033] In the present application, the bipyridine derivative is preferably 4,4'-dihydroxy-2,2'-bipyridine.
[0034] In the present application, the fluorine-containing compound is preferably tetramethylammonium fluoride.
[0035] In the present application, the organic solvent is preferably N,N-dimethylformamide and / or diethylene glycol dimethyl ether.
[0036] In the present application, the azole compound is preferably methylbenzotriazole.
[0037] In the present application, the weight ratio of the bipyridine derivative to the azole compound is preferably 1:1-1:2.
[0038] In the present application, the weight ratio of the bipyridine derivative to the azole compound is more preferably 2:3.
[0039] In the present application, the pH of the cleaning solution is 2-11.
[0040] In the present application, the azole compound in the low-corrosion fluorine-containing cleaning agent for semiconductor aluminum processing has a unique effect:
[0041] Firstly, the nitrogen atom in the azole ring has high electron density, which can form chemical adsorption with the metal surface through π bond conjugation effect, especially after protonation (-NH + ), the electrostatic interaction with the metal surface is enhanced;
[0042] Secondly, the introduction of methyl group (-CH3) increases the hydrophobicity of the molecule and improves its stability in organic solvents; at the same time, the steric hindrance of the methyl group can enhance the compactness of the adsorption layer;
[0043] Third, the conjugated system of the azole ring can interact with F - Formation of weak hydrogen bonds (NH…F), reducing F - Direct attack on metal surfaces.
[0044] In this invention, the bipyridine derivative in the low-corrosion fluorinated cleaning agent used in semiconductor aluminum manufacturing processes has a unique role:
[0045] Firstly, the hydroxyl group (-OH) and the nitrogen atom of bipyridine can react with metal ions (such as Fe). 2+ Cu 2+ Coordinate bonds are formed, and the lone pairs of electrons of N and O atoms combine with the empty orbitals of the metal to form a monomolecular adsorption layer on the surface;
[0046] Secondly, the aromatic structure of the bipyridine ring provides a hydrophobic barrier, reducing H... + F - The penetration of corrosion ions into the metal surface;
[0047] Third, the hydroxyl group exists in a protonated form (-OH2) under acidic conditions. + It can achieve corrosion inhibition by combining with the negatively charged areas on the metal surface through electrostatic interaction.
[0048] An unexpected discovery was made: in this invention, the synergistic effect of azole compounds and bipyridine derivatives has a unique function.
[0049] Firstly, the combination of bipyridine derivatives and azole compounds not only protects metals and substrates from corrosion individually, but also produces a synergistic effect, improving corrosion inhibition efficiency through a "dual adsorption mechanism." Specifically, azole compounds preferentially adsorb onto active sites on the metal surface (such as dislocations and defects) via strong coordination bonds, providing initial adsorption nuclei; while bipyridine derivatives act as an "extension layer" through π-π conjugation, laterally connecting the azole anchors, filling pores, and forming a "network composite film."
[0050] Secondly, the large π bond of bipyridine can hinder F through electrostatic repulsion. - Approaching the metal surface, and the hydroxyl groups can react with F. - Hydrogen bonds are formed. Meanwhile, the nitrogen atom of methylazole undergoes protonation (-NH4+). + ) and F - Forming ion pairs reduces free F - The concentration of fluoride ions is reduced to minimize its damage to the protective film. The compound system can maintain stable adsorption even at high fluoride ion concentrations, while single azole compounds show stable adsorption at high fluoride ion concentrations. - It is easily desorbed in the environment.
[0051] The fluorine-containing compound can be transmitted via F - Decompose the cross-linked photoresist network.
[0052] [Second technical solution] [Second technical solution]
[0053] A preparation method of the above-mentioned low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process, comprising the following steps:
[0054] Step 1: respectively take the respective amount of each component;
[0055] Step 2: stir the organic solvent and the fluorine-containing compound uniformly, then add the bipyridine derivative and the azole compound, stir uniformly, and obtain the low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process.
[0056] [Third technical solution] [Third technical solution]
[0057] A use method of the above-mentioned low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process, comprising the following steps:
[0058] Step 1: immerse the chip in the fluorine-containing cleaning agent at 25-50℃, and the immersion time is 10-40 minutes, to obtain the immersed chip;
[0059] Step 2: rinse the immersed chip in ethanol at least twice, and the cleaning process of the chip is completed.
[0060] [Fourth technical solution] [Fourth technical solution]
[0061] The use of the above-mentioned low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process in cleaning semiconductor chips.
[0062] The present application provides a low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process, a preparation method and application thereof, and has the following advantages:
[0063] 1. The bipyridine derivative and the azole compound are compounded to improve the corrosion inhibition efficiency through the "double adsorption mechanism", wherein the lone pair electrons of the heterocyclic nitrogen atom in the azole compound form a strong coordination bond with the metal, the adsorption energy is high, and the stability is strong; the pi conjugated system of the bipyridine derivative can extend to the entire pyridine ring to form a planar molecular structure, which is easy to form a transversely extended adsorption layer on the metal surface, transversely connect between the azole anchor points, and fill the pores to form a "net-like composite film".
[0064] 2. It has environmental adaptability and anti-interference mechanism. The large pi bond of bipyridine can hinder F - from approaching the metal surface through electrostatic repulsion, and the hydroxyl group can form a hydrogen bond with F - , and the nitrogen atom of the methyl azole forms an ion pair with F - by protonation (-NH + ), thereby reducing the concentration of free F - and reducing the damage to the protective film.
[0065] Therefore, the fluorine-containing cleaning agent can be used for cleaning photoresist in semiconductor manufacturing, has good protection effect on metal electrodes such as Al, can effectively inhibit corrosion and prolong service life, and has very good application prospect and large-scale industrialization potential in the field of semiconductor chip cleaning. BRIEF DESCRIPTION OF DRAWINGS
[0066] Fig. 1 : Microscope picture of Al piece before cleaning, magnified 500 times;
[0067] Fig. 2 : Microscope picture of Al piece after soaking in fluorine-containing cleaning agent prepared by using Example 1, magnified 500 times;
[0068] Fig. 3 : Microscope picture of Al piece after soaking in fluorine-containing cleaning agent prepared by using Comparative Example 1, magnified 500 times. DETAILED DESCRIPTION
[0069] The application will be further described below in combination with specific examples and drawings:
[0070] In the application, Examples 1-10 and Comparative Examples 1-5 disclose various fluorine-containing cleaning agents, which comprise components and mass ratios as shown in Table 1 and Table 2.
[0071] Table 1 Components and ratios of fluorine-containing cleaning agent solution of Examples 1-10
[0072] Table 2 Components and ratios of fluorine-containing cleaning agent of Comparative Examples 1-5
[0073] The preparation method of the low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process of the application is as follows:
[0074] Step 1: weigh each component according to the respective amount;
[0075] Step 2: stir the organic solvent and the fluorine-containing compound uniformly, then add the bipyridine derivative and the azole compound, and stir uniformly to obtain the low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process.
[0076] The use method of the low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process of the application is as follows:
[0077] Step 1: soak the chip in the fluorine-containing cleaning agent at 25-50°C, and the soaking time is 10-40 minutes to obtain the soaked chip;
[0078] Step 2: rinse the soaked chip in ethanol for at least twice to complete the cleaning process of the chip.
[0079] Performance test and description:
[0080] The test method of performance 1 Al corrosion rate is:
[0081] Four-probe method is used to test the corrosion performance of different fluorine-containing cleaning agents on metal Al.
[0082] The specific test method is: 2*2 cm 2 Al sheet is immersed in the cleaning agent at 40℃ for 30min.
[0083] Then the thickness of Al sheet before and after immersion in fluorine-containing cleaning agent is measured by four-probe method, and the corrosion rate (Å / min, also known as "etching rate") of each is calculated, so as to investigate the corrosion rate of different cleaning agents on metal.
[0084] The performance test results of fluorine-containing cleaning agents obtained in examples 1-10 and comparative examples 1-5 are shown in table 3.
[0085] Table 3 test data
[0086] Analysis and description of test results:
[0087] From the test data in table 3, it can be seen that the Al metal corrosion of the present application is small, while the comparative example 1 lacks bipyridine derivative, resulting in increased corrosion; the comparative example 2 lacks nitrogen azole compound, resulting in increased corrosion; the comparative example 3 lacks methyl of nitrogen azole, resulting in increased corrosion; the comparative example 4 lacks hydroxyl of bipyridine, resulting in increased corrosion; the comparative example 5 contains hydroxyl pyridine, resulting in increased corrosion.
[0088] Further comparison and description are made by the drawings in the specification:
[0089] Fig. 1 The microscope picture of Al sheet before cleaning is enlarged 500 times; Fig. 2 The microscope picture of Al sheet after immersion in fluorine-containing cleaning agent prepared by example 1 is enlarged 500 times; Fig. 3 The microscope picture of Al sheet after immersion in fluorine-containing cleaning agent prepared by comparative example 1 is enlarged 500 times.
[0090] It can be seen from Figs. 1-3 that the bright and dark field color of Al sheet after treatment by fluorine-containing cleaning agent prepared by comparative example 1 is darker than that of the original sheet, which proves that comparative example 1 corrodes Al sheet seriously, while the bright and dark field color of Al sheet after immersion in fluorine-containing cleaning agent prepared by example 1 is the same as that of the original sheet, which proves that example 1 can effectively inhibit the corrosion of Al sheet.
[0091] In summary, the core innovation of the application is:
[0092] The application designs a low-corrosion fluorine-containing cleaning agent for semiconductor aluminum process, which has a good protective effect on Al and other metals through the chemical synergy of coordination adsorption + hydrophobic shielding + fluorine ion capture of "strong anchor point + wide coverage" of the corrosion inhibitor, can effectively inhibit the corrosion of the metals, prolong the service life, and has a very good application prospect and large-scale industrialization potential in the field of semiconductor chip cleaning.
[0093] The application is described above in combination with the embodiments and the drawings, and it is obvious that the implementation of the application is not limited by the above-mentioned modes, and various improvements using the method concept and technical solution of the application or direct application of the concept and technical solution of the application to other occasions without improvement are all within the protection scope of the application.
Claims
1. A low-corrosion fluorinated cleaning agent for semiconductor aluminum manufacturing processes, characterized in that, Based on parts by weight, it includes the following components: 5-20 parts of fluorine-containing compounds; 40-90 parts organic solvent; 0.1-5 parts of bipyridine derivatives; Nitrazine compounds, 0.1-5 parts; The bipyridine derivative is a bipyridine compound with introduced functional substituents.
2. The low-corrosion fluorine-containing cleaning agent for semiconductor aluminum processing according to claim 1, characterized in that: The bipyridine derivative is a bipyridine compound with an introduced hydroxyl group.
3. The low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to claim 1 or 2, characterized in that: The bipyridine derivative is one or more of 4,4'-dihydroxy-2,2'-bipyridine, 4-hydroxymethyl-4'-methyl-2,2'-bipyridine, 5-hydroxy-2,2'-bipyridine, and 6,6'-dihydroxy-2,2'-bipyridine.
4. The low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to claim 1, characterized in that: The fluorinated compound is one or more of ammonium fluoride, hydrogen fluoride, tetrabutylammonium fluoride, tetramethylammonium fluoride, and ammonium hydrogen fluoride.
5. The low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to claim 1, characterized in that: The organic solvent is one or more of sulfoxide, sulfone, imidazolidinone, pyrrolidone, imidazolinone, amide, and alcohol ether.
6. The low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to claim 1, characterized in that: The azole compounds are one or more of methylbenzotriazole, 1-methyl-1,2,4-triazole, 1-methyl-1,2,3-triazole, 3-methyl-1H-1,2,4-triazole, 1,4-dimethyl-1H-1,2,3-triazole and 4-methyl-1H-1,2,3-triazole.
7. The low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to claim 1, characterized in that: The weight ratio of the bipyridine derivative to the azole compound is 1:1 to 1:
2.
8. A method for preparing a low-corrosion fluorinated cleaning agent for semiconductor aluminum processing 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: Stir the organic solvent and fluorine-containing compound evenly, then add the bipyridine derivative and nitrazole compound, and stir evenly to obtain the low-corrosion fluorine-containing cleaning agent for semiconductor aluminum processing.
9. A method of using the low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to any one of claims 1-7, characterized in that, Includes the following steps: Step 1: Immerse the chip in the fluorine-containing cleaning agent at 25-50℃ for 10-40 minutes to obtain the immersed chip; Step 2: Rinse the soaked chip in ethanol at least twice to complete the chip cleaning process.
10. The use of a low-corrosion fluorinated cleaning agent for semiconductor aluminum processing according to any one of claims 1-7 in cleaning semiconductor chips.