Cleaning composition

Abstract

The present invention relates to a cleaning composition, specifically comprising a basic compound, an alcohol amine, a corrosion inhibitor, a chelating agent, and a solvent. The positive effects of the present invention include the effective removal of post-CMP wafer surface residues, non-corrosiveness to copper wiring and low-k materials, and a wide process window, and are expected to be widely used in semiconductor post-CMP cleaning processes.

Description

[Technical Field]

[0001] The present invention relates to the field of semiconductor manufacturing processes, and in particular to a cleaning composition for post-chemical mechanical polishing (CMP) processes. [Background Art]

[0002] In semiconductor manufacturing processes, copper is most commonly used as a wiring material for advanced semiconductors due to its low resistance and ease of processing. Fabrication of copper devices requires chemical deposition and chemical mechanical polishing (CMP). Since the flatness of the polished copper surface produced by the CMP process is one of the most important determinants of wiring performance, post-CMP cleaning must effectively remove residues generated by the polishing process. For this reason, most CMP slurries and post-CMP cleaning agents contain one or more corrosion inhibitors selected to form a temporary protective layer on the surface of copper wiring. However, when an organic film remains on the surface of copper wiring after cleaning, the presence of such a film hinders subsequent processes such as chemical vapor deposition (CVD) and may impair the final performance of the copper wiring. The present invention provides a cleaning composition that can effectively remove wafer surface residues after CMP, does not corrode copper wiring and low-k materials, has a wide process window, and is expected to have wide applications in post-CMP cleaning for semiconductors. [Summary of the Invention]

[0003] In order to overcome the technical problem that conventional cleaning compositions cannot simultaneously achieve effective removal of wafer surface residues and good corrosion protection effects for copper wiring and low-k materials, the present invention provides a cleaning composition comprising a basic compound, an alcohol amine, a corrosion inhibitor, a chelating agent and a solvent.

[0004] Preferably, the basic compound is potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, choline hydroxide, aqueous ammonia, or benzyltriethylammonium hydroxide (BTEAH). Tetrabutylphosphonium hydroxide (TBPH) A cleaning composition characterized by being one or more selected from the group consisting of (2-hydroxyethyl)trimethylammonium hydroxide, (2-hydroxyethyl)triethylammonium hydroxide, (2-hydroxyethyl)tripropylammonium hydroxide, (1-hydroxypropyl)trimethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide (DEDMAH), dimethyldipropylammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide.

[0005] Preferably, the content of the basic compound is 0.05% to 35% by mass.

[0006] Preferably, the content of the basic compound is 0.5% to 30% by mass.

[0007] Preferably, the alcohol amine is one or more selected from ethanolamine, diethanolamine, triethanolamine, diethylene glycolamine, isopropanolamine, hydroxyethylethylenediamine, N-methylethanolamine, N,N-dimethylethanolamine, N-methyldiethanolamine, and N,N,N'-trimethyl-N'-(2-hydroxyethyl)ethylenediamine.

[0008] Preferably, the alcohol amine content is 0.05% to 35% by mass.

[0009] Preferably, the alcoholamine content is 0.5% to 30% by mass.

[0010] Preferably, the cleaning composition is characterized in that the corrosion inhibitor is one or more selected from the group consisting of diprophylline, 5-aminoimidazole-4-carboxamide, barbituric acid, 3-methyl(triazennyl)imidazole-4-carboxamide, adenine, adenosine, xanthine, hypoxanthine, guanine, guanosine, 5-phenyltetrazol, ascorbic acid, 5-benzylthiotetrazol, 5-mercapto-1-phenyl-1H-tetrazol, 5-benzyl-1H-tetrazol, 3-amino-5-mercapto-1,2,4-triazole, 5-amino-4-carboxamideimidazole, 5-amino-1,2,4-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, and methylthiotetrazol.

[0011] Preferably, the content of the corrosion inhibitor is 0.005% by mass to 15% by mass.

[0012] Preferably, the content of the corrosion inhibitor is 0.05% to 10% by mass.

[0013] Preferably, the cleaning composition is characterized in that the chelating agent is one or more selected from the group consisting of ammonium tartrate, tartaric acid, ammonium acetate, acetic acid, iminodiacetic acid, EDTA, 1,2-cyclohexanediaminetetraacetic acid, oxalic acid, glycolic acid, malic acid, malonic acid, glyceric acid, betaine, gallic acid, and phthalic acid.

[0014] Preferably, the content of the chelating agent is 0.005% by mass to 15% by mass.

[0015] Preferably, the content of the chelating agent is 0.05% to 10% by mass.

[0016] Preferably, the solvent is water.

[0017] Preferably, the pH value of the basic compound is 9 to 13.5.

[0018] As advantageous effects of the present invention, it is capable of effectively removing wafer surface residues after CMP, has no corrosiveness to copper wirings and low-k materials, and provides a wide process window, so that wide application in post-CMP cleaning processes for semiconductors is expected. [Mode for Carrying out the Invention]

[0019] Hereinafter, the present invention will be further described with reference to specific examples. It should be understood that these examples are only intended to illustrate the present invention and not to limit the scope of the present invention. It should also be understood that after reading the description of the present invention, those skilled in the art can make various changes or modifications to the present invention, and such equivalent forms also fall within the scope defined by the appended claims of the present application.

[0020] Cleaning compositions are prepared according to the specific types and contents of the respective components described in Table 1.

[0021] Taking Example 4 as an example, the preparation method and addition order of the composition of the present invention are shown below. 1) Add 15 parts of tetramethylammonium hydroxide into a beaker. 2) Add 15 parts of triethanolamine. 3) Add 65 parts of water, and stir for 10 minutes using a magnetic stirrer. 4) Add 2.5 parts of ammonium acetate while stirring. 5) Add 2 parts of guanine while stirring. 6) Continue stirring until the mixture becomes transparent, to obtain the target cleaning composition.

[0022] [Table 1-1] [Table 1-2]

[0023] Further, some examples and comparative examples 1 to 3 were selected to conduct a performance test, and the results are shown in Table 2.

[0024] Specific test conditions are as follows.

[0025] Copper etching rate (Å / min): A diluted solution is prepared by mixing the above solution and water at a mass ratio of 1:30, and heated to the test temperature in a reaction vessel. After immersing a copper wafer for 5 minutes, the wafer is washed with deionized water, dried with nitrogen gas, and the change in resistance before and after etching is measured by the four-point probe method to calculate the etching rate.

[0026] Cobalt etching rate (Å / min): A diluted solution is prepared by mixing the above solution and water at a mass ratio of 1:30, and heated to the test temperature in a reaction vessel. After immersing a cobalt wafer for 5 minutes, the wafer is washed with deionized water, dried with nitrogen gas, and the change in resistance before and after etching is measured by the four-point probe method to calculate the etching rate.

[0027] Change in copper surface roughness after cleaning (nm): A diluted solution is prepared by mixing the above solution and water at a mass ratio of 1:30, and heated to the test temperature in a reaction vessel. After immersing a copper wafer for 5 minutes, the wafer is washed with deionized water, dried with nitrogen gas, and the change in Ra value before and after cleaning is measured by AFM.

[0028] Change in cobalt surface roughness after cleaning (nm): A diluted solution is prepared by mixing the above solution and water at a mass ratio of 1:30, and heated to the test temperature in a reaction vessel. After immersing a cobalt wafer for 5 minutes, the wafer is washed with deionized water, dried with nitrogen gas, and the change in Ra value before and after cleaning is measured by AFM.

[0029]

Table 2

[0030] A comparison of Examples 1-6 and Proportional Reactions 1-6 revealed that when the type and content of the basic compound and alcoholamine were the same, the cleaning composition of Example 1-6 significantly reduced the etching rate of copper and cobalt, confirming that the corrosion inhibitor and chelating agent selected in the present invention exerted an etching rate suppression effect. Test results for Proportional Reactions 7 and 8 showed that when the content of the basic compound or alcoholamine was excessive or insufficient, although the etching rate of the metal surface of the cleaning composition decreased, the metal surface roughness after cleaning did not reach the desired level. Furthermore, Table 3 shows the results of copper wafer surface particle and organic matter residue removal ability tests conducted on selected examples and proportional ratios.

[0031] The specific test conditions are as follows:

[0032] Copper wafer surface particle residue test: A diluted solution was prepared by mixing the above solution with water in a mass ratio of 1:30 and heating it to the experimental temperature in a reaction vessel. The copper wafer was cut to a size of 3 cm x 3 cm, polished for 60 seconds using a CMP apparatus, and then washed for 60 seconds using the cleaning composition of the present invention in a cleaning apparatus. After washing with deionized water for 60 seconds, it was dried with nitrogen gas. For the treated copper wafer, the number of surface particles was measured by SP2, the amount of residual organic matter was analyzed by XPS, and the number of scratches was evaluated by microscopy. The results of the comparison with commercially available similar products are shown in Table 3.

[0033] [Table 3]

[0034] From the above results, it was confirmed that the composition of the present invention effectively cleans copper surface residue after CMP, suppresses etching of copper well, controls the metal corrosion rate to 3 Å / min or less, and does not leave any residue on the wafer surface. The comparison results between Example 4 and a commercially available product demonstrated that the present invention is applicable to post-CMP cleaning in semiconductor manufacturing, and that the raw materials are readily available and easy to prepare. Comparing the test results of Example 4 with those of Proportional Reactions 4 and 9-11 under the same processing temperature conditions, the number of particles and residual organic matter on the copper surface were significantly reduced after using the cleaning composition of Example 4, and the number of scratches was also controlled within an ideal range. Analysis of the combined test results in Table 2 demonstrated that the corrosion inhibitor selected in the present invention not only effectively reduces the etching rate of the cleaning composition on the metal surface but also significantly improves the morphology of the metal surface after cleaning. On the other hand, the cleaning compositions of Proportional Reactions 9-11 lacked either a basic compound, an alcohol amine, or a chelating agent, and it was confirmed that the technical effects were inferior, with increased particle residue, increased organic matter residue, and significantly higher scratch counts on the metal surface after cleaning compared to commercially available products. These comparisons demonstrate that the present invention, by combining specific types of basic compounds, alcohol amines, corrosion inhibitors, and chelating agents in predetermined concentrations, simultaneously achieves the removal of organic residues from the surface after CMP, the suppression of etching rates for copper wiring and low-k materials, and the optimization of the surface morphology after cleaning, thus demonstrating broad applicability to semiconductor post-CMP cleaning processes.

[0035] The embodiments of the present invention are suitable for implementation and do not limit the present invention in any way. Those skilled in the art can realize equivalent effective embodiments by making changes or modifications to the technical content disclosed above. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical idea of ​​the present invention, without departing from the content of the technical solution means of the present invention, are all included within the scope of the technical solution means of the present invention.

Claims

1. A composition for post-cleaning of alkaline CMP in semiconductor devices having copper wiring, It contains basic compounds, alcohol amines, corrosion inhibitors, chelating agents, and solvents. The basic compound is contained in an amount ranging from 0.05% by mass to 35% by mass. The aforementioned alcoholamine is contained in an amount ranging from 0.05% by mass to 35% by mass. A post-cleaning composition for alkaline CMP, characterized in that the corrosion inhibitor is one or more selected from the group consisting of xanthine, adenosine, guanine, barbituric acid, 5-benzylthiotetrazole, 5-benzyl-1H-tetrazole, and methylthiotetrazole.

2. In the cleaning composition according to claim 1, A cleaning composition characterized in that the basic compound is one or more selected from the group consisting of potassium hydroxide, sodium hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, choline hydroxide, aqueous ammonia, benzyltriethylammonium hydroxide (BTEAH), tetrabutylphosphonium hydroxide (TBPH), (2-hydroxyethyl)trimethylammonium hydroxide, (2-hydroxyethyl)triethylammonium hydroxide, (2-hydroxyethyl)tripropylammonium hydroxide, (1-hydroxypropyl)trimethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide (DEDMAH), dimethyldipropylammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide.

3. In the cleaning composition according to claim 1, A cleaning composition characterized in that the basic compound is contained in an amount ranging from 0.5% by mass to 30% by mass.

4. In the cleaning composition according to claim 1, A cleaning composition characterized in that the alcohol amine is one or more selected from the group consisting of ethanolamine, diethanolamine, triethanolamine, diethylene glycolamine, isopropanolamine, hydroxyethylethylenediamine, N-methylethanolamine, N,N-dimethylethanolamine, N-methyldiethanolamine, and N,N,N'-trimethyl-N'-(2-hydroxyethyl)ethylenediamine.

5. In the cleaning composition according to claim 1, A cleaning composition characterized in that the alcoholamine is contained in an amount ranging from 0.5% by mass to 30% by mass.

6. In the cleaning composition according to claim 1, A cleaning composition characterized in that the corrosion inhibitor is contained in an amount ranging from 0.005% by mass to 15% by mass.

7. In the cleaning composition according to claim 6, A cleaning composition characterized in that the corrosion inhibitor is contained in an amount ranging from 0.05% by mass to 10% by mass.

8. In the cleaning composition according to claim 1, A cleaning composition characterized in that the chelating agent is one or more selected from the group consisting of ammonium tartrate, tartaric acid, ammonium acetate, acetic acid, iminodiacetic acid, EDTA, 1,2-cyclohexanediaminetetraacetic acid, oxalic acid, glycolic acid, malic acid, malonic acid, glyceric acid, betaine, gallic acid, and phthalic acid.

9. In the cleaning composition according to claim 1, A cleaning composition characterized in that the chelating agent is contained in an amount ranging from 0.005% by mass to 15% by mass.

10. In the cleaning composition according to claim 9, A cleaning composition characterized in that the chelating agent is contained in an amount ranging from 0.05% by mass to 10% by mass.

11. In the cleaning composition according to claim 1, A cleaning composition characterized in that the solvent is water.

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