Efficient semiconductor chip cleaning solution and preparation method and application thereof

Abstract

The invention relates to a high-efficiency semiconductor chip cleaning solution which comprises the following components in parts by weight: 20-40 parts of an amine compound; 3-10 parts of a corrosion inhibitor; 20-45 parts of an organic solvent; 0.1 to 0.8 part of a chelating agent; and 15-50 parts of ultrapure water. The invention further discloses a preparation method and application of the cleaning fluid. Dihydroxycoumarin and paeonol both contain hydrogen bond donors and hydrogen bond receptors, hydrogen bond interaction can be generated when the dihydroxycoumarin and the paeonol are compounded, due to the hydrogen bond interaction between the dihydroxycoumarin and the paeonol, a double-ring structure is formed between the dihydroxycoumarin and the paeonol, and hydroxyl and carbonyl in the structures of the dihydroxycoumarin and the paeonol can be complexed with aluminum ions, so that the dihydroxycoumarin and the paeonol can be compounded with the aluminum ions, and the aluminum ions can be A double-ring structure formed after the two components cooperate with each other can be better complexed with aluminum ions, and the cleaning agent has excellent cleaning efficiency on chips.

Description

Technical Field

[0001] The present invention belongs to the field of chip cleaning, and particularly relates to a high-efficiency semiconductor chip cleaning solution, a preparation method thereof, and an application thereof. Background Art

[0002] In the manufacture of semiconductor integrated circuits, large-scale, high-density, and miniaturization are gradually developing. In the manufacture of integrated circuits, the coating, exposure, and imaging of the photoresist layer are necessary process steps for the pattern manufacturing of components. Before the next process step is carried out after the last step of patterning (i.e., after the coating, imaging, ion implantation, and dry etching of the photoresist layer), the residues of the photoresist layer material need to be completely removed. For chips, after being processed by the dry etching process, ideal etching rates, selectivity ratios, sidewall morphologies, etc. can be obtained. However, after dry etching, inorganic, organic, organic-metal polymers, photoresist, and other post-etch residues will be generated, which will affect the stability and yield of subsequent chip processes. However, the removal efficiency of post-etch residues is not only affected by the complexity of the material but also by the location where the post-etch residues are formed.

[0003] Common wafer cleaning and processing technologies include wet cleaning and dry cleaning. Wet cleaning technology occupies the dominant position in the cleaning process of semiconductor factories due to its simplicity and high efficiency. Wet cleaning generally uses inorganic chemical solvents with strong corrosiveness and oxidizing properties, so that the impurity particles on the wafer surface react chemically with the solvent, generating gases or being dissolved and separated from the wafer surface, and the wafer can be cleaned in about 12 - 15 minutes.

[0004] Although the cleaning time is short, the inorganic chemical solvents with strong corrosiveness and oxidizing properties in wet cleaning also have strong corrosiveness to metals and non-metals (such as silicon oxide, low k, etc.).

[0005] Therefore, in view of the problems existing in the current cleaning solution, such as low removal efficiency of post-etch residues, etc., it is very urgent to develop a high-efficiency semiconductor chip cleaning solution. Summary of the Invention

[0006] The technical problems solved by the present invention: The traditional cleaning solution has poor cleaning effect and low removal efficiency of post-etch residues, etc.

[0007] In view of the technical problems existing in the prior art, the present invention provides a high-efficiency semiconductor chip cleaning solution, a preparation method thereof, and an application thereof. Using this high-efficiency semiconductor chip cleaning solution, ultrasonic process cooperation for cleaning is not required, and the post-etch residues can be quickly and efficiently removed only under the condition of pure immersion process.

[0008] It should be noted that in the present invention, unless otherwise specified, the specific meaning of "including" involving compositional limitations and descriptions includes both the open-ended "including", "comprising" and their similar meanings, and also the closed-ended "consisting of" and their similar meanings.

[0009] To solve the above-mentioned existing technical problems, the present invention adopts the following solutions:

[0010] An efficient semiconductor chip cleaning solution, characterized in that, calculated by weight, it comprises the following components:

[0011] 20 - 40 parts of amine compounds;

[0012] 3 - 10 parts of corrosion inhibitor;

[0013] 20 - 45 parts of organic solvent;

[0014] 0.1 - 0.8 part of chelating agent;

[0015] 15 - 50 parts of ultrapure water.

[0016] Furthermore, the amine compounds include hydroxylamine compounds and alkanolamine compounds.

[0017] Furthermore, the hydroxylamine compounds are one or more of hydroxylamine hydrochloride, hydroxylamine sulfate, hydroxylamine, methylhydroxylamine, N,N - diethylhydroxylamine, N - phenylhydroxylamine, N - tert - butylhydroxylamine and N - isopropylhydroxylamine.

[0018] Furthermore, the alkanolamine compounds are one or more of monoethanolamine, N - methylmonoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diethylaminoethanol, N - ethyldiethanolamine and diglycolamine.

[0019] Furthermore, the mass ratio of the hydroxylamine compounds to the alkanolamine compounds is 1:1 - 5.

[0020] Furthermore, the mass ratio of the hydroxylamine compounds to the alkanolamine compounds is 1:3.

[0021] Furthermore, the corrosion inhibitor is a sugar alcohol compound.

[0022] Furthermore, the corrosion inhibitor is one or more of xylitol, sorbitol, maltitol, L - mannitol and erythritol.

[0023] Furthermore, the organic solvent is a water - soluble organic solvent.

[0024] Furthermore, the organic solvent is a sulfone organic solvent and / or an amide organic solvent.

[0025] Further, the organic solvent is one or more of N,N-dimethylformamide, N-formylmorpholine, sulfolane, dimethyl sulfoxide, and diphenyl sulfoxide.

[0026] Further, the chelating agent includes dicoumarol and paeonol.

[0027] Further, the mass ratio of dicoumarol to paeonol is 1-3:1.

[0028] Further, the ultrapure water is deionized water with a resistance of at least 18 MΩ.

[0029] The present invention also discloses a preparation method of an efficient semiconductor chip cleaning solution, which is characterized by including the following steps:

[0030] Step 1: Weigh each component in their respective amounts.

[0031] Step 2: Add the corrosion inhibitor, chelating agent, and amine compound into a container, stir until completely dissolved, then add the remaining components and stir evenly to obtain the semiconductor chip cleaning solution.

[0032] The present invention also discloses a usage method of an efficient semiconductor chip cleaning solution, which is characterized by including the following steps:

[0033] Step 1: Immerse the semiconductor chip in the semiconductor chip cleaning solution at 60-75 °C for 5-10 minutes to obtain an immersed semiconductor chip.

[0034] Step 2: Rinse the immersed semiconductor chip with an isopropyl alcohol solution for 1-5 minutes, and then rinse it with ultrapure water for 1-5 minutes to complete the cleaning process of the semiconductor chip.

[0035] The present invention also discloses the use of an efficient semiconductor chip cleaning solution for cleaning semiconductor chips.

[0036] In the cleaning solution system of the present invention, in order to further optimize the effect, each component can be preferably selected: 32-40 parts of amine compound; 4-8 parts of corrosion inhibitor; 25-40 parts of organic solvent; 0.3-0.6 parts of chelating agent; 20-40 parts of ultrapure water.

[0037] In the present invention, the hydroxylamine compound is hydroxylamine.

[0038] In the present invention, the alkanolamine compound is N-methylmonoethanolamine and diethylene glycol amine.

[0039] In the present invention, the mass ratio of N-methylmonoethanolamine to diethylene glycol amine is 2:1.

[0040] In the present invention, the corrosion inhibitor is sorbitol.

[0041] In the present invention, the mass ratio of dicoumarol to paeonol is 2:1.

[0042] In the present invention, the chelating agent has a unique function:

[0043] Both dicoumarol and paeonol contain hydrogen bond acceptors and hydrogen bond donors. Due to hydrogen bonding, the complexation of the two has a synergistic chelating property for aluminum ions, thereby effectively removing the residues after etching on the chip.

[0044] In the present invention, in the method of using the cleaning solution, the soaking temperature in step 1 is 65 - 75 °C, and the soaking time is 5 - 8 minutes.

[0045] In the present invention, in the method of using the cleaning solution, the rinsing time with isopropanol solution in step 2 is 1 - 3 min, and the rinsing time with ultrapure water is 1 - 3 min.

[0046] The present invention provides an efficient semiconductor chip cleaning solution, its preparation method and application, which have the following beneficial effects:

[0047] 1. The hydroxyl groups in the symmetrical structure of dicoumarol in the chelating agent of the present invention can form a complex with aluminum ions. Moreover, there are hydroxyl groups (-OH) and carbonyl groups (C=O) in the structure of paeonol. The oxygen atom is a "hard base", while the aluminum ion is a "hard acid". A complexation reaction can occur between paeonol and aluminum ions to form a six-membered ring conjugated structure.

[0048] 2. Since both dicoumarol and paeonol contain hydrogen bond donors and hydrogen bond acceptors, the complexation of the two will produce hydrogen bonding, resulting in the formation of a bicyclic structure between dicoumarol and paeonol. In addition to the hydroxyl groups and C=O in the structures of dicoumarol and paeonol that can complex aluminum ions, the bicyclic structure formed after their synergy can also better complex with aluminum ions, and has excellent cleaning ability for the chip in about 5 - 8 minutes.

[0049] 3. In the present invention, using a combination of a water-soluble organic solvent and ultrapure water to form a composite solvent system can enhance the wetting and solubilization of the residues after etching. Moreover, the hydrogen ions in water can provide protons, which can improve the reaction activity of amine substances, making the cleaning solution have strong cleaning ability.

[0050] Therefore, the cleaning solution of the present invention has very good application prospects and the potential for large-scale industrial promotion in the field of semiconductor chip cleaning. Brief Description of the Drawings

[0051] Figure 1 : SEM image of the chip after being cleaned with the semiconductor chip cleaning solution of Comparative Example 2 for 5 minutes, magnified 22,000 times.

[0052] Figure 2 : SEM image of the chip magnified 22,000 times after being cleaned with the semiconductor chip cleaning solution of Comparative Example 1 for 5 minutes.

[0053] Figure 3 : SEM image of the chip magnified 22,000 times after being cleaned with the semiconductor chip cleaning solution of Example 1 for 5 minutes. Specific Embodiments

[0054] The present invention will be further described below in conjunction with specific embodiments and the accompanying drawings:

[0055] Table 1 Examples 1 - 10

[0056]

[0057]

[0058] Table 2 Comparative Examples 1 - 3

[0059]

[0060] Table 3 Test Data

[0061]

[0062] The preparation method of the high-efficiency semiconductor chip cleaning solution of the present invention comprises the following steps:

[0063] Step 1: Weigh each component in their respective amounts;

[0064] Step 2: Add the corrosion inhibitor, chelating agent, and amine compound into a container, and stir until completely dissolved. Then add the remaining components and stir evenly to obtain the semiconductor chip cleaning solution.

[0065] The usage method of the high-efficiency semiconductor chip cleaning solution of the present invention comprises the following steps:

[0066] Step 1: Immerse the semiconductor chip in the semiconductor chip cleaning solution at 70 °C for 5 - 10 minutes to obtain the immersed semiconductor chip;

[0067] Step 2: Rinse the immersed semiconductor chip with isopropyl alcohol solution for 1 minute, and then rinse it with ultrapure water for 1 minute to complete the cleaning process of the semiconductor chip.

[0068] Regarding performance testing and description:

[0069] The test method for Performance 1 cleaning efficiency is as follows:

[0070] Using silicon nitride as a substrate, after etching a chip with a metal Al bottom at the bottom of the hole, a large amount of post-etch residues remained on it. The chip was cleaned with the cleaning solutions of the above-mentioned examples and comparative examples of the present invention. The cleaning treatment method includes the following steps:

[0071] Step 1: Immerse the semiconductor chip cleaning solution in the solution at 70 °C for the chip until the post-etch residues are completely removed. The time when the post-etch residues are completely removed is the cleaning time. Record the cleaning time. See Table 3 for the test results to obtain the chip after immersion.

[0072] Step 2: Rinse the immersed chip with isopropyl alcohol for at least 1 min first, and then rinse it with ultrapure water for at least 1 min. After drying with nitrogen, the cleaning treatment of the chip is completed.

[0073] Use SEM to observe the cleaning conditions of the chips after the cleaning treatments of Comparative Example 1, 2 and Example 1 after soaking for 5 min. See the test results in Figures 1-3 。

[0074] The test method for the corrosion rate of Performance 2 is as follows:

[0075] Use a four-probe resistance measuring instrument to test the corrosion performance of different cleaning solutions on metals. The specific test method is as follows: Immerse a wafer plated with an Al layer of 2×2 cm 2 in the cleaning solution at 70 °C for 5 min.

[0076] Then use a four-probe resistance measuring instrument to measure the difference in film thickness before and after the wafer, and calculate the corrosion rate( i.e., / min, which can also be called the "etching rate") to investigate the corrosion rate of different cleaning solutions on metals. See Table 3 for the test results.

[0077] The ultrapure water used in the above steps is deionized water with a resistance of at least 18 MΩ.

[0078] Analysis and explanation of the test results:

[0079] It can be seen from the test data in Table 3 that Example 1 of the present invention has a lower corrosion rate under the condition of having better cleaning ability.

[0080] In Comparative Example 1, only paeonol is used as a chelating agent. Since the hydroxyl group (-OH) and carbonyl group (C=O) in the structure of paeonol are not sufficient to achieve a good chelating effect, Comparative Example 1 has a poor cleaning effect;

[0081] Similarly, in Comparative Example 2, only dicoumarol is used as a chelating agent. Since the groups in the structure of dicoumarol are also not sufficient to achieve a good chelating effect, Comparative Example 2 has a poor cleaning effect;

[0082] Comparative Example 3 uses only hydroxylamine as the amine compound. Due to the strong reducing property of hydroxylamine, the corrosion rate of Al is relatively high.

[0083] Further comparison is made through the attached drawings in the specification:

[0084] Figure 1 This is a SEM image of the chip magnified 22,000 times after being cleaned for 5 minutes using the semiconductor chip cleaning solution of Comparative Example 2. Figure 2 This is a SEM image of the chip magnified 22,000 times after being cleaned for 5 minutes using the semiconductor chip cleaning solution of Comparative Example 1. Figure 3 This is a SEM image of the chip magnified 22,000 times after being cleaned for 5 minutes using the semiconductor chip cleaning solution of Example 1.

[0085] from Figure 1 It can be seen that there is no corrosion on the bottom surface of the chip hole structure, but there are many etching residues. Figure 2 It can be seen that there is no corrosion on the bottom surface of the chip hole structure, but there is still a small amount of etching residue. Figure 3 It can be seen that there is no corrosion on the bottom surface of the chip hole structure and no etching residue on the chip.

[0086] pass Figure 1 , Figure 2 and Figure 3 The comparison can prove that the cleaning effect of adding only dihydroxycoumarin or paeonol cleaning solution is weak, and there are etching residues on the chip. After adding dihydroxycoumarin and paeonol composite chelating agent, the cleaning effect of the cleaning solution is enhanced, and there is no residue on the chip after cleaning.

[0087] The dihydroxycoumarin and paeonol used in the present invention both contain hydrogen bond donors and hydrogen bond acceptors, and the two can produce hydrogen bonding when combined. Due to the hydrogen bonding between the two, a bicyclic structure is formed between the dihydroxycoumarin and paeonol. In addition to the hydroxyl and carbonyl groups in the dihydroxycoumarin and paeonol structures being able to complex with aluminum ions, the bicyclic structure formed after the two cooperate with each other can also be better complexed with aluminum ions, and has excellent corrosion inhibition ability for chips, can achieve cleaning of etching residues in about 5-8 minutes, and has low corrosion to metals and non-metals (such as silicon oxide, low k, etc.).

[0088] 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 highly efficient semiconductor chip cleaning solution, characterized in that: Calculated by weight, it includes the following components:

2. The high-efficiency semiconductor chip cleaning solution according to claim 1, characterized in that: The amine compounds include hydroxylamine compounds and alcoholamine compounds.

3. The high-efficiency semiconductor chip cleaning solution according to claim 2, characterized in that: The hydroxylamine compound is one or more of hydroxylamine hydrochloride, hydroxylamine sulfate, hydroxylamine, methylhydroxylamine, N,N-diethylhydroxylamine, N-phenylhydroxylamine, N-tert-butylhydroxylamine and N-isopropylhydroxylamine.

4. The high-efficiency semiconductor chip cleaning solution according to claim 2, characterized in that: The alcoholamine compound is one or more of monoethanolamine, N-methylmonoethanolamine, diethanolamine, triethanolamine, isopropanolamine, diethylaminoethanol, N-ethyldiethanolamine and diglycolamine.

5. The high-efficiency semiconductor chip cleaning solution according to claim 1, characterized in that: The corrosion inhibitor is a sugar alcohol compound.

6. The high-efficiency semiconductor chip cleaning solution according to claim 1, characterized in that: The organic solvent is a water-soluble organic solvent.

7. The high-efficiency semiconductor chip cleaning solution according to claim 1, characterized in that: The chelating agent includes dihydroxycoumarin and paeonol.

8. A method for preparing a high-efficiency semiconductor chip cleaning solution according to any one of claims 1 to 7, characterized in that The steps include: Step 1: Weigh each component in its respective amount; Step 2: Add the corrosion inhibitor, chelating agent and amine compound into a container and stir until they are completely dissolved, then add the remaining components and stir evenly to obtain the semiconductor chip cleaning solution.

9. A method for using the high-efficiency semiconductor chip cleaning solution according to any one of claims 1 to 7, characterized in that The following steps are involved: Step 1: soaking the semiconductor chip in the semiconductor chip cleaning solution at 60-75° C. for 5-10 minutes to obtain a soaked semiconductor chip; Step 2: Rinse the soaked semiconductor chip with an isopropyl alcohol solution for 1-5 minutes, and then rinse with ultrapure water for 1-5 minutes, thereby completing the cleaning process of the semiconductor chip.

10. Use of the high-efficiency semiconductor chip cleaning solution according to any one of claims 1 to 7 for cleaning semiconductor chips.

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