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 more particularly to cleaning compositions for post-chemical mechanical polishing (CMP) processes. [Background technology]

[0002] In semiconductor manufacturing processes, copper is the most commonly used interconnect material for advanced semiconductors due to its low resistivity and ease of processing. Fabrication of copper devices requires chemical deposition and chemical mechanical polishing (CMP). Because the flatness of the polished copper surface produced by the CMP process is one of the most important determinants of interconnect performance, post-CMP cleaning must effectively remove residues generated by the polishing process. For this reason, many CMP slurries and post-CMP cleaning agents contain one or more corrosion inhibitors selected to form a temporary protective layer on the copper interconnect surface. However, if organic films remain on the copper interconnect surface after cleaning, their presence can interfere with subsequent processes, such as chemical vapor deposition (CVD), and impair the final performance of the copper interconnect. The present invention provides a cleaning composition that effectively removes post-CMP wafer surface residues without corroding copper interconnects or low-k materials. Its wide process window makes it suitable for a wide range of applications in semiconductor post-CMP cleaning. Summary of the Invention

[0003] To overcome the technical problem that conventional cleaning compositions cannot effectively remove wafer surface residues while simultaneously achieving good corrosion protection 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 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), (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% by mass to 35% by mass.

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

[0007] Preferably, the alcoholamine 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 content of the alcohol amine is 0.05% by mass to 35% by mass.

[0009] Preferably, the content of the alcohol amine is 0.5% by mass to 30% by mass.

[0010] Preferably, the corrosion inhibitor is one or more selected from the group consisting of diprophylline, 5-aminoimidazole-4-carboxamide, barbituric acid, 3-methyl(triazenyl)imidazole-4-carboxamide, adenine, adenosine, xanthine, hypoxanthine, guanine, guanosine, 5-phenyltetrazole, ascorbic acid, 5-benzylthiotetrazole, 5-mercapto-1-phenyl-1H-tetrazole, 5-benzyl-1H-tetrazole, 3-amino-5-mercapto-1,2,4-triazole, 5-amino-4-carboxamidoimidazole, 5-amino-1,2,4-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, and methylthiotetrazole.

[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% by mass 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% by mass 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] The positive effects of the present invention include the ability to effectively remove 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 applied in semiconductor post-CMP cleaning processes. DETAILED DESCRIPTION OF THE INVENTION

[0019] The present invention will be further described below with reference to specific examples. It should be understood that these examples are merely illustrative of the present invention and do not 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 the equivalent forms thereof also fall within the scope defined by the appended claims of this application.

[0020] A cleaning composition is prepared according to the specific type and content of each component listed in Table 1.

[0021] Using Example 4 as an example, the preparation method and addition order of this composition are shown below. 1) Add 15 parts of tetramethylammonium hydroxide to a beaker. 2) Add 15 parts of triethanolamine. 3) Add 65 parts of water and stir for 10 minutes using a magnetic stirrer. 4) While stirring, add 2.5 parts of ammonium acetate. 5) While stirring, add 2 parts guanine. 6) Stirring is continued until the mixture becomes transparent to obtain the desired cleaning composition.

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

[0023] Furthermore, some of the Examples and Comparative Examples 1-3 were selected and subjected to performance tests, and the results are shown in Table 2.

[0024] The specific test conditions are as follows:

[0025] Copper etching rate (Å / min): Prepare a diluted solution of the above solution and water at a mass ratio of 1:30 and heat it to the experimental temperature in a reaction vessel. After immersing a copper wafer in the solution for 5 minutes, rinse it with deionized water and dry it with nitrogen gas. The change in resistance before and after etching is measured using the four-point probe method, and the etching rate is calculated.

[0026] Cobalt etching rate (Å / min): Prepare a diluted solution of the above solution and water at a mass ratio of 1:30 and heat it to the experimental temperature in a reaction vessel. After immersing the cobalt wafer in the solution for 5 minutes, rinse with deionized water and dry with nitrogen gas. The change in resistance before and after etching is measured using the four-point probe method, and the etching rate is calculated.

[0027] Change in copper surface roughness after cleaning (nm): Prepare a diluted solution of the above solution and water at a mass ratio of 1:30 and heat it in a reaction vessel to the experimental temperature. After immersing the copper wafer for 5 minutes, rinse it with deionized water, dry it with nitrogen gas, and measure the change in the Ra value before and after using an AFM.

[0028] Change in cobalt surface roughness after cleaning (nm): Prepare a diluted solution of the above solution and water at a mass ratio of 1:30 and heat it in a reaction vessel to the experimental temperature. After immersing the cobalt wafer for 5 minutes, rinse it with deionized water, dry it with nitrogen gas, and measure the change in Ra value before and after using an AFM.

[0029] [Table 2]

[0030] A comparison of Examples 1-6 and Comparative Examples 1-6 showed that when the types and contents of the basic compound and alcoholamine were the same, the cleaning compositions of Examples 1-6 significantly reduced the etching rates of copper and cobalt, confirming that the corrosion inhibitors and chelating agents selected in the present invention exert an etching rate suppression effect. The test results of Comparative Examples 7 and 8 revealed that when the contents of the basic compound or alcoholamine were too high or too low, the metal surface etching rate of the cleaning compositions decreased, but the metal surface roughness after cleaning did not reach the desired level. Furthermore, some examples and comparative examples were selected and subjected to a test for removing particles and organic residues from the surface of a copper wafer. The results are shown in Table 3.

[0031] The specific test conditions are as follows:

[0032] Copper wafer surface particle residue test: A diluted solution of the above solution and water was prepared in a mass ratio of 1:30 and heated to the test temperature in a reaction vessel. Copper wafers were cut into 3 cm x 3 cm pieces, polished for 60 seconds using a CMP device, and then cleaned for 60 seconds using the cleaning composition of the present invention in a cleaning device. The wafers were then rinsed for 60 seconds with deionized water and dried with nitrogen gas. The processed copper wafers were evaluated for surface particle counts using SP2, organic residue analysis using XPS, and the number of scratches using a microscope. The results, compared with similar commercially available 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 removes copper surface residues after CMP while effectively suppressing etching of copper, making it possible to control the metal corrosion rate to 3 Å / min or less, and not leaving any residue on the wafer surface. Comparison of Example 4 with commercially available products 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 Comparative Examples 4 and 9-11 under the same processing temperature conditions, the number of particles and residual organic matter on the copper surface after use of the cleaning composition of Example 4 was significantly reduced, 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 inhibitors selected in the present invention not only effectively reduced the etching rate of the cleaning composition on metal surfaces, but also significantly improved the morphology of the metal surface after cleaning. In contrast, the cleaning compositions of Comparative Examples 9-11, lacking either a basic compound, alcohol amine, or chelating agent, exhibited increased residual particles and organic matter levels on the metal surface after cleaning, significantly exceeding those of the commercially available products, demonstrating inferior technical effectiveness. These comparisons demonstrate that the present invention, by combining specific types of basic compounds, alcohol amines, corrosion inhibitors, and chelating agents in specified amounts, can simultaneously remove organic residues from post-CMP surfaces, suppress the etching rate of copper wiring and low-k materials, and optimize post-cleaning surface morphology, demonstrating its broad applicability to semiconductor post-CMP cleaning processes.

[0035] It should be noted that the embodiments of the present invention have suitable implementations and do not limit the present invention in any way. Those skilled in the art can realize equivalently 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 of the present invention are all included in the scope of the technical solution of the present invention.

Claims

1. 1. A composition for alkaline post-CMP cleaning of semiconductor devices having copper interconnects, comprising: An alkaline post-CMP cleaning composition comprising a basic compound, an alcohol amine, a corrosion inhibitor, a chelating agent and a solvent.

2. 2. The cleaning composition according to claim 1, The cleaning composition is 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. 2. The cleaning composition according to claim 1, A cleaning composition characterized in that the basic compound is contained in an amount ranging from 0.05% by mass to 35% by mass.

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

5. 2. The cleaning composition according to claim 1, The cleaning composition, wherein the alcoholamine is at least one 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.

6. 2. The cleaning composition according to claim 1, A cleaning composition characterized in that the alcohol amine is contained in an amount ranging from 0.05% by mass to 35% by mass.

7. 7. The cleaning composition according to claim 6, A cleaning composition characterized in that the alcohol amine is contained in an amount ranging from 0.5% by mass to 30% by mass.

8. 2. The cleaning composition according to claim 1, The cleaning composition is characterized in that the corrosion inhibitor is one or more selected from the group consisting of diprophylline, allopurinol, ascorbic acid, 5-aminoimidazole-4-carboxamide, barbituric acid, 3-methyl(triazenyl)imidazole-4-carboxamide, adenine, adenosine, xanthine, guanine, guanosine, 5-phenyltetrazole, ascorbic acid, 5-benzylthiotetrazole, 5-mercapto-1-phenyl-1H-tetrazole, 5-benzyl-1H-tetrazole, 3-amino-5-mercapto-1,2,4-triazole, 5-amino-4-carboxamidoimidazole, 5-amino-1,2,4-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, methylthiotetrazole, and methimazole.

9. 2. The cleaning composition according to claim 1, A cleaning composition characterized in that the corrosion inhibitor is contained in an amount of 0.005% by mass to 15% by mass.

10. 10. The cleaning composition according to claim 9, The cleaning composition contains the corrosion inhibitor in an amount of 0.05% by mass to 10% by mass.

11. 2. The cleaning composition according to claim 1, The 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.

12. 2. The cleaning composition according to claim 1, A cleaning composition characterized in that the chelating agent is contained in an amount of 0.005% by mass to 15% by mass.

13. 13. The cleaning composition of claim 12, A cleaning composition characterized in that the chelating agent is contained in an amount ranging from 0.05% by mass to 10% by mass.

14. 2. The cleaning composition according to claim 1, A cleaning composition characterized in that the solvent is water.

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