Low-corrosion and high-stability semiconductor chip cleaning solution as well as preparation method and application thereof

Abstract

The invention provides a low-corrosion and high-stability semiconductor chip cleaning solution as well as a preparation method and application thereof. The low-corrosion and high-stability semiconductor chip cleaning solution comprises the following components in parts by weight: 10-30 parts of hydroxylamine and derivatives thereof; 1-10 parts of a corrosion inhibitor; 20-50 parts of an organic base; 1-10 parts of a chelating agent; 10 to 20 parts of ultrapure water; and 10-30 parts of an organic solvent. The invention further discloses a preparation method of the low-corrosion and high-stability semiconductor chip cleaning fluid and application of the low-corrosion and high-stability semiconductor chip cleaning fluid in the field of semiconductor chip cleaning. The low-corrosion and high-stability semiconductor chip cleaning fluid is mild in cleaning condition, simple to operate, low in chip corrosion risk, stable in performance and long in service life, and can still achieve relatively high cleaning efficiency under the pure soaking process condition without matching of an ultrasonic process with cleaning. The low-corrosion and high-stability semiconductor chip cleaning fluid has good application prospects and large-scale industrial popularization potential in the field of semiconductor chip cleaning.

Description

Technical Field

[0001] The invention relates to semiconductor chip cleaning liquid technology, and in particular to a low-corrosion, high-stability semiconductor chip cleaning liquid and a preparation method and application thereof. Background Art

[0002] Semiconductors are materials with controllable resistivity formed by doping other metals on silicon. They are materials with conductivity between conductors and insulators. Chips are a general term for semiconductor products and are the carriers of integrated circuits. Chips have a wide range of applications and have been widely used in cars, routers, mobile phones, televisions and other products in daily life. In the preparation of semiconductor materials, each production process may bring impurities. For example, the precise doping area and the doping interface area may be contaminated by mobile metal ions (MIC). Because they have strong mobility, they will move in the semiconductor and cause the electrical performance of the device to fail. Common MICs include sodium, potassium, iron, copper, nickel, aluminum, etc. Therefore, each production process involves a cleaning process, and the quality of cleaning will not only directly affect the next process, but also may affect the yield of the product. At present, due to the continuous reduction in chip size, the production process has stricter requirements for impurities on the chip surface, and each process in chip production may cause contamination to the manufactured chip. Trace impurities of one millionth or even one billionth may affect the physical properties of semiconductor chips, thereby destroying the normal performance of semiconductor devices. In order to prevent harmful impurities from randomly entering the device and causing chip failure, the chip needs to be thoroughly cleaned.

[0003] According to the composition of pollutants, pollutants can be roughly divided into four categories: particles, organic matter, metal pollutants and oxides. Different pollutants have different treatment methods. Although there are specific removal methods for different pollutants, each step in the chip manufacturing process will have more or less impact on the final product. At present, chip cleaning fluids have disadvantages such as long cleaning time, high operating temperature, poor residue removal ability, short service life, and high metal corrosion to varying degrees, and cannot be used to remove etching residues after multiple processes. Therefore, it is necessary to develop low-corrosion, highly stable semiconductor chip cleaning fluids. Summary of the invention

[0004] The purpose of the present invention is to propose a low-corrosion, highly stable semiconductor chip cleaning solution in response to the problems of long cleaning time, high operating temperature, poor residue removal ability, short service life and high metal corrosion in current chip cleaning solutions to varying degrees. The chip cleaning solution has mild cleaning process conditions, simple operation, low risk of chip corrosion, stable performance and long service life, and can still achieve a high cleaning efficiency under pure immersion process conditions without the need for ultrasonic cleaning process.

[0005] 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", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a low-corrosion, high-stability semiconductor chip cleaning solution, comprising the following components in weight proportions: 10-30 parts of hydroxylamine and its derivatives; Corrosion inhibitor 1-10 parts; 20-50 parts of organic base; 1-10 parts of chelating agent; 10-20 parts of ultrapure water; 10-30 parts of organic solvent.

[0007] Furthermore, the hydroxylamine and its derivatives are one or more of hydroxylamine hydrochloride, hydroxylamine sulfate, hydroxylamine nitrate, hydroxylamine, N-methylhydroxylamine, N,N-dimethylhydroxylamine, N,N-diethylhydroxylamine, N-phenylhydroxylamine and N-tert-butylhydroxylamine.

[0008] Furthermore, the hydroxylamine and its derivatives are preferably one or more of hydroxylamine sulfate, hydroxylamine and N-methylhydroxylamine.

[0009] Furthermore, the hydroxylamine and its derivatives are 10-20 parts.

[0010] The hydroxylamine and its derivatives of the present invention are functional active components. As strong nucleophilic reducing agents, they can reduce the metal in the etching residue from a higher oxidation state to a lower oxidation state, promote the dissolution of the metal residue, and can react with the C=O bond in the photoresist to convert it into easily soluble oximes, thereby improving the dissolution efficiency of the etching residue.

[0011] Furthermore, the corrosion inhibitor is one or more of 2,4-dihydroxy-3-nitroquinoline, 7-methoxy-4-methyl-2(1H)-quinolinone, 4-methoxy-6-nitroquinolin-2(1H)-one, 2-heptyl-3-hydroxy-4(1H)-quinolinone, 6-nitro-2(1H)-quinolinone and 7-hydroxy-3,4-dihydroquinolone.

[0012] Furthermore, the corrosion inhibitor is preferably 7-hydroxy-3,4-dihydroquinolone.

[0013] Furthermore, the corrosion inhibitor is 1-8 parts.

[0014] The corrosion inhibitor of the present invention can form multiple adsorption centers. For example, quinolone has a conjugated structure, which can provide electrons and receive electrons. The amino and methoxy groups contained in the structure tend to provide electrons, and the hydroxyl and nitro groups tend to receive electrons. During adsorption, the quinolone and amino groups in the molecule will provide electrons to the 3d orbital of the metal to form a coordination bond. At the same time, the 3d orbital of the metal will feed back electrons to the quinolone and hydroxyl groups in the molecule to form a feedback bond, thereby forming multiple adsorption centers and effectively reducing metal corrosion.

[0015] Furthermore, the organic base is one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, choline and tetramethylguanidine.

[0016] Furthermore, the organic base is preferably tetramethylammonium hydroxide and / or tetramethylguanidine.

[0017] Furthermore, the organic base is 20-35 parts.

[0018] Furthermore, the chelating agent is one or more of hydroxamic acid, salicylic hydroxamic acid, benzohydroxamic acid, pyrazine hydroxamic acid and acetohydroxamic acid.

[0019] Furthermore, the chelating agent is preferably salicylic hydroxamic acid.

[0020] Furthermore, the chelating agent is 1-8 parts.

[0021] The chelating agent of the present invention can form a soluble chelate with an organic metal compound to avoid its precipitation and improve the cleaning effect. For example, since salicylic acid has oxygen and nitrogen containing lone pairs of electrons in its molecular structure and is close to each other, it can chelate with metal ions to form a stable chelate, so it can form a soluble chelate with the organic metal compound reduced by hydroxylamine and its derivatives to avoid its precipitation and improve the cleaning effect. At the same time, when the hydroxylamine molecules are free in the solution for cleaning, the chelating agent will complex the metal ions in the solution, reduce the decomposition of hydroxylamine during the cleaning process, and improve the cleaning life and the stability of the cleaning solution.

[0022] Furthermore, the ultrapure water is deionized water with a resistance ≥ 18 MΩ.

[0023] Furthermore, the ultrapure water is 10-15 parts.

[0024] Furthermore, the organic solvent is one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol methyl ether, diethylene glycol butyl ether, dipropylene glycol butyl ether, tripropylene glycol butyl ether, propylene glycol methyl ether acetate, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylpropionamide, N,N-dimethylpropionamide, N,N-diethylacetamide, cyclopentane, dimethyl sulfoxide, and 1,4-butyrolactone.

[0025] Furthermore, the organic solvent is preferably dimethyl sulfoxide.

[0026] Furthermore, the organic solvent is 15-25 parts.

[0027] Another object of the present invention is to disclose a method for preparing a low-corrosion, high-stability semiconductor chip cleaning solution, comprising the following steps: Step 1: Weigh each component in its respective amount; Step 2: Add all components into a container and stir at room temperature until all materials are completely dissolved to prepare a low-corrosion, highly stable semiconductor chip cleaning solution.

[0028] Furthermore, the stirring time in step 2 is 1-6h.

[0029] Another object of the present invention is to disclose the application of a low-corrosion, high-stability semiconductor chip cleaning solution in the field of semiconductor chip cleaning.

[0030] Furthermore, a method for cleaning a semiconductor chip using a low-corrosion, high-stability semiconductor chip cleaning solution comprises the following steps: S1: immersing the semiconductor chip in the low-corrosion, high-stability semiconductor chip cleaning solution to obtain a soaked semiconductor chip; S2: The semiconductor chip after immersion is placed in ultrapure water for rinsing, thereby completing the cleaning process of the semiconductor chip.

[0031] Furthermore, the soaking condition in S1 is soaking at 20°C-50°C for 10-30 minutes.

[0032] Furthermore, S2 is flushed twice or more.

[0033] The low-corrosion, high-stability semiconductor chip cleaning solution of the present invention and its preparation method and application have the following advantages compared with the prior art: 1) The hydroxylamine and its derivatives of the present invention are functional active components. As a strong nucleophilic reducing agent, they can reduce the metal in the etching residue from a higher oxidation state to a lower oxidation state, promote the dissolution of the metal residue, and can react with the C=O bond in the photoresist to convert it into easily soluble oximes, thereby improving the dissolution efficiency of the etching residue.

[0034] 2) The corrosion inhibitor of the present invention can form multiple adsorption centers. For example, quinolone has a conjugated structure, which can provide electrons as well as receive electrons. The amino and methoxy groups contained in the structure tend to provide electrons, while the hydroxyl and nitro groups tend to receive electrons. During adsorption, the quinolone and amino groups in the molecule will provide electrons to the 3d orbital of the metal to form a coordination bond. At the same time, the 3d orbital of the metal will feed back electrons to the quinolone and hydroxyl groups in the molecule to form a feedback bond, thereby forming multiple adsorption centers and effectively reducing metal corrosion.

[0035] 3) The chelating agent of the present invention can form a soluble chelate with an organic metal compound to improve the cleaning effect. For example, since salicylic acid has oxygen and nitrogen with lone pairs of electrons in its molecular structure and is close to each other, it can chelate with metal ions to form a stable chelate. Therefore, it can form a soluble chelate with the organic metal compound reduced by hydroxylamine and its derivatives to avoid its precipitation and improve the cleaning effect. At the same time, when the hydroxylamine molecules are free in the solution for cleaning, the chelating agent will complex the metal ions in the solution, reduce the decomposition of hydroxylamine during the cleaning process, and improve the cleaning life and stability of the cleaning solution.

[0036] 4) The low-corrosion, high-stability semiconductor chip cleaning solution of the present invention is environmentally friendly, pollution-free, has low volatile loss, good stability, excellent cleaning effect on side wall polymer impurities, will not corrode the substrate, and has the advantages of a large implementation range and a large operating window. After the chip is cleaned by the cleaning solution of the present invention, there is no need to use acetone for rinsing, and it only needs to be rinsed with pure water, which is harmless to the environment and human body.

[0037] Therefore, the low-corrosion and highly stable semiconductor chip cleaning solution of the present invention has good application prospects and large-scale industrial promotion potential in the field of cleaning semiconductor chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a SEM picture of the chip after cleaning with the cleaning solution of Example 1, with a magnification of 22,000 times.

[0039] Figure 2 This is a SEM picture of the chip after cleaning with the cleaning solution of Comparative Example 1, with a magnification of 22,000 times.

[0040] Figure 3 This is a SEM picture of the chip after cleaning with the cleaning solution of Comparative Example 2, with a magnification of 22,000 times. DETAILED DESCRIPTION

[0041] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that: Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0042] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0043] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0044] In this specification, the word "may" means both performing a certain process and not performing a certain process.

[0045] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0046] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0047] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0048] Examples 1-6 Examples 1-6 disclose a variety of low-corrosion, high-stability semiconductor chip cleaning solutions, the components and weight ratios of which are shown in Table 1, and the preparation methods thereof are as follows: Step 1: Weigh each component in its respective amount; Step 2: Add all components into a container and stir at room temperature for 2 hours until all materials are completely dissolved to prepare a low-corrosion, highly stable semiconductor chip cleaning solution.

[0049] Table 1 Components and weight ratios of low-corrosion, high-stability semiconductor chip cleaning solutions of Examples 1-6

[0050] Comparative Examples 1-3 Comparative Examples 1-3 disclose a variety of semiconductor chip cleaning solutions, the components and weight ratios of which are shown in Table 2, and the preparation methods thereof are the same as those of Example 1.

[0051] Table 2 Components and weight ratios of semiconductor chip cleaning solutions in Comparative Examples 1-3

[0052] The semiconductor chip cleaning solutions of Examples 1-6 and Comparative Examples 1-3 were tested respectively, and the test results are shown in Table 3.

[0053] Table 3 Test data

[0054] It can be seen from Table 3 that after cleaning with the cleaning solution of Examples 1-6, the aluminum corrosion rate can be controlled at 0.40-0.69Å / min; while after cleaning with the cleaning solution of Comparative Examples 1-3, the aluminum corrosion rate increases.

[0055] Figure 1 This is a SEM picture of the chip after cleaning with the cleaning solution of Example 1, with a magnification of 22,000 times. Figure 2 This is a SEM picture of the chip after cleaning with the cleaning solution of Comparative Example 1, with a magnification of 22,000 times. Figure 3 This is a SEM picture of the chip after cleaning with the cleaning solution of Comparative Example 2, with a magnification of 22,000 times. It can be seen that after cleaning with Comparative Example 1, there are obvious residues, and after cleaning with Comparative Example 2, there are obvious corrosion marks, while after cleaning with Example 1, a good cleaning effect can be achieved without residue, and it has good compatibility with Al and almost no corrosion.

[0056] About performance testing and description: Etch rate test method Four probes are used to test the film thickness change before and after aluminum etching to calculate the etching rate. The specific test method is: A 2cm×2cm chip (with an aluminum film coated on it) was immersed in a cleaning solution at 40°C for 30 minutes. After being taken out, it was rinsed twice in ultrapure water and dried with nitrogen. The chip was then measured with four probes to obtain the film thickness and calculate the etching rate (Å / min, i.e. Å / minute), thereby examining the etching rate of the cleaning solution on aluminum.

[0057] 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 aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned 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 low-corrosion, high-stability semiconductor chip cleaning solution, characterized in that: The composition includes the following components in weight ratio: 10-30 parts of hydroxylamine and its derivatives; Corrosion inhibitor 1-10 parts; 20-50 parts of organic base; 1-10 parts of chelating agent; 10-20 parts of ultrapure water; 10-30 parts of organic solvent.

2. The low-corrosion, high-stability semiconductor chip cleaning solution according to claim 1, characterized in that: The hydroxylamine and its derivatives are one or more of hydroxylamine hydrochloride, hydroxylamine sulfate, hydroxylamine nitrate, hydroxylamine, N-methylhydroxylamine, N,N-dimethylhydroxylamine, N,N-diethylhydroxylamine, N-phenylhydroxylamine and N-tert-butylhydroxylamine.

3. The low-corrosion, high-stability semiconductor chip cleaning solution according to claim 1, characterized in that: The corrosion inhibitor is one or more of 2,4-dihydroxy-3-nitroquinoline, 7-methoxy-4-methyl-2(1H)-quinolinone, 4-methoxy-6-nitroquinolin-2(1H)-one, 2-heptyl-3-hydroxy-4(1H)-quinolinone, 6-nitro-2(1H)-quinolinone and 7-hydroxy-3,4-dihydroquinolone.

4. The low-corrosion, high-stability semiconductor chip cleaning solution according to claim 1, characterized in that: The organic base is one or more of tetramethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, choline and tetramethylguanidine.

5. The low-corrosion, high-stability semiconductor chip cleaning solution according to claim 1, characterized in that: The chelating agent is one or more of hydroxamic acid, salicylic hydroxamic acid, benzohydroxamic acid, pyrazine hydroxamic acid and acetohydroxamic acid.

6. The low-corrosion, high-stability semiconductor chip cleaning solution according to claim 1, characterized in that: The organic solvent is one or more of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol methyl ether, diethylene glycol butyl ether, dipropylene glycol butyl ether, tripropylene glycol butyl ether, propylene glycol methyl ether acetate, N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylpropionamide, N,N-dimethylpropionamide, N,N-diethylacetamide, cyclopentane, dimethyl sulfoxide, and 1,4-butyrolactone.

7. A method for preparing the low-corrosion, high-stability semiconductor chip cleaning solution according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1: Weigh each component in its respective amount; Step 2: Add all components into a container and stir at room temperature until all materials are completely dissolved to prepare a low-corrosion, highly stable semiconductor chip cleaning solution.

8. Use of the low-corrosion, high-stability semiconductor chip cleaning solution according to any one of claims 1 to 6 in the field of semiconductor chip cleaning.

9. The use according to claim 8, characterized in that: A method for cleaning a semiconductor chip using a low-corrosion, high-stability semiconductor chip cleaning solution comprises the following steps: S1: immersing the semiconductor chip in the low-corrosion, high-stability semiconductor chip cleaning solution to obtain a soaked semiconductor chip; S2: The semiconductor chip after immersion is placed in ultrapure water for rinsing, thereby completing the cleaning process of the semiconductor chip.

10. The use according to claim 9, characterized in that: S1 immersion conditions: immersion at 20℃-50℃ for 10-30min; And / or, the number of flushing times of S2 is two or more.

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