Composition for removing etching residues

Abstract

The invention provides a composition for removing residues after aluminum and copper etching and application of the composition. The chemical etching composition comprises organic alkali, a corrosion inhibitor, an organic solvent, polyol, deionized water and the like. By adopting the composition disclosed by the invention, residues after etching can be effectively removed, etching of AlCu, TiN / Ti and silicon oxide is avoided, and the composition has a good application prospect in a semiconductor etching process.

Description

Technical Field

[0001] The present invention relates to the technical field of chemical reagents for semiconductor manufacturing, and particularly to the field of high-end semiconductor cleaning. Background Art

[0002] In the manufacturing process of semiconductor devices, many steps in the manufacturing and packaging processes of integrated circuit chips are etching processes. Therefore, in recent years, many different types of etching methods have been developed to remove corresponding materials, sometimes removing materials in selective areas. These etching methods are extremely critical and decisive steps for etching different layers that make up the final integrated circuit chip. These methods have been applied to varying degrees.

[0003] Positive photoresist, as a masking material, has been widely used to form patterns and channels on a substrate, so that the patterns can then be etched, and then patterns are formed in the substrate. The final step of manufacturing the substrate includes removing the unexposed photoresist material from the substrate. However, methods such as plasma etching and reactive ion etching used to form patterns and channels in the substrate make it more difficult to remove the photoresist material. For example, in the production of multi-layer wiring at the back-end of the line interconnection of logic devices, reactive ion etching is used to generate channels through the interlayer dielectric, so that silicon, silicide, or metal wiring on one horizontal plane provides contact with the wiring on the next horizontal plane. These channels usually expose Al, AlCu, Cu, Ti, TiN, Ta, TaN, silicon, or silicide, etc. Residues of complex mixtures generated by the reactive ion etching method may include re-sputtered oxides and may also contain a small amount of organic materials in the photoresist used to form the channels. Similarly, when manufacturing conductive lines of Al, Cu, and their alloys, there will be etching residues on the conductive lines, and these residues must be removed. The residues are difficult to remove, and at the same time, selectivity is required for other exposed dielectrics and metals, etc., which poses a challenge to the performance of the removal composition.

[0004] Therefore, there is a need to provide a selective method for removing photoresist and etching residues, which has higher selectivity for etching residues compared to the removal effect on metals, silicon, silicides, and re-sputtered oxides that may also be exposed to the cleaning composition. Summary of the Invention

[0005] The purpose of the present invention is to provide a composition for removing residues after aluminum-copper etching and its application. The chemical etching composition includes organic base, corrosion inhibitor, organic solvent, polyol, deionized water, etc. By using the composition of the present invention, residues after etching can be effectively removed, while avoiding etching of AlCu, TiN / Ti, and silicon oxide, and it has good application prospects in the semiconductor etching process.

[0006] The present invention discloses an etching residue removal composition, which is characterized by comprising: an organic base, a corrosion inhibitor, an organic solvent, a polyol, and deionized water.

[0007] Further, the organic base is selected from one or more of N-methyldiethanolamine, N,N-dimethyldiethanolamine, diisopropanolamine, diethanolamine, ethanolamine, triethanolamine, n-propanolamine, isopropanolamine, triisopropanolamine, diethylene glycol amine, N-methylethanolamine, N,N-dimethylethanolamine, triethylene glycol amine.

[0008] Further, the corrosion inhibitor is selected from compounds represented by the following formula: R1(R2,R3,R4,R5,R6,R7), wherein R1 is a phenyl group, and R2-R7 are each independently H, an alkyl group, a hydroxyl group, an amino group, or a carboxyl group.

[0009] Further, the organic solvent is selected from one or more of isopropanol, butanol, butylene carbonate, ethylene carbonate, propylene carbonate, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPM), tripropylene glycol methyl ether (TPM), dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, N-methylpyrrolidone, N-ethylpyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide.

[0010] Further, the polyol is selected from one or more of ethylene glycol, propylene glycol, propylene glycol, butanediol, glycerol, glucose, xylitol, sorbitol, mannitol, inositol, pentaerythritol, maltitol, lactitol.

[0011] Further, the mass percentage content range of the organic base is 10wt%-80wt%.

[0012] Further, the mass percentage content range of the corrosion inhibitor is 0.1wt%-15wt%.

[0013] Further, the mass percentage content range of the organic solvent is 10%-70wt%.

[0014] Further, the mass percentage content range of the polyol is 0.1%-5wt%.

[0015] Further, the pH value is 8-13.

[0016] Using the etching composition of the present invention can effectively remove the etching residues, while avoiding etching of AlCu, TiN / Ti, and silicon oxide, and has a large operation window, showing good application prospects in semiconductor etching processes. Detailed Embodiments

[0017] The advantages of the present invention will be further elaborated below in combination with specific embodiments.

[0018] Prepare the chemical compositions of Examples 1-13 and Comparative Examples 1-5 according to the components and their contents in Table 1, and make up the mass percentage to 100% with deionized water.

[0019] Table 1 Components and Contents of Examples 1-13 and Comparative Examples 1-5

[0020]

[0021]

[0022]

[0023] In order to further test the performance of the above chemical cleaning solution, select the compositions of some examples and Comparative Examples 1-5 to conduct etching tests on AlCu, TiN and silicon oxide respectively. The specific test conditions are as follows:

[0024] Etching Rates of AlCu and TiN Place the etching composition in a reactor and heat it to 70°C. Then place the AlCu film in it for etching for 30 minutes, and then calculate the etching rate by measuring the thickness change before and after etching with a four-probe resistance tester.

[0025] Etching Rate of Silicon Oxide Place the etching composition in a reactor and heat it to 70°C. Then place the silicon oxide film in it for etching for 30 minutes, and then calculate the etching rate by measuring the thickness change before and after etching with a non-metallic film thickness tester.

[0026] The etching rate data obtained from the test are shown in Table 2.

[0027] Table 2 Etching Rates and Selectivity of Some Examples and Comparative Examples

[0028]

[0029]

[0030] Note: Effect of removing residues after etching: ◎ Basically removed completely; ○ A small amount of residue; △ More residue; × A large amount of residue

[0031] As can be seen from Table 2, the cleaning solution of the present invention has strong cleaning ability, can effectively remove the residues after etching, and has only a small corrosion rate for AlCu, silicon oxide and titanium nitride. The comparison between Example 7 and Comparative Example 1 shows that without adding deionized water, the residues after etching cannot be effectively removed, and the etching rate of AlCu will decrease to a certain extent. The comparison between Example 7 and Comparative Example 2 shows that without adding polyol, it has a certain impact on the removal effect of the residues after etching. The comparison between Example 7 and Comparative Example 3 shows that without adding a solvent, it also has a certain impact on the removal effect of the residues after etching, and the etching rate of AlCu will increase. The comparison between Example 7 and Comparative Example 4 shows that without adding an inhibitor, it has a greater impact on the etching rate of AlCu, and the rate increases significantly. At the same time, it also has a certain impact on the removal of residues. The comparison between Example 7 and Comparative Example 5 shows that without adding an organic base, the residues after etching cannot be removed, and there is no etching of AlCu either.

[0032] In summary, the positive and progressive effects of the present invention are as follows: a composition for wet removal of residues after etching is provided, and the composition may include an organic base, an inhibitor, an organic solvent, a polyol, deionized water, etc. By using the etching composition of the present invention, the residues after etching can be effectively removed, while avoiding etching of AlCu, TiN / Ti and silicon oxide, and having a large operation window, thus having good application prospects in the semiconductor etching process.

[0033] It should be noted that the embodiments of the present invention have better implementability and do not limit the present invention in any form. Any person skilled in the art may use the disclosed technical content to change or modify it into an equivalent effective embodiment. However, as long as it does not depart from the technical content of the present invention, any modification, equivalent change or modification made to the above embodiments according to the technical essence of the present invention still falls within the scope of the technical solution of the present invention.

Claims

1. An etching residue removal composition, characterized in that Comprising: an organic base, a corrosion inhibitor, an organic solvent, a polyol and deionized water, wherein the organic base is selected from one or more of N-methyldiethanolamine, N,N-dimethyldiethanolamine, diisopropanolamine, diethanolamine, ethanolamine, triethanolamine, n-propanolamine, isopropanolamine, triisopropanolamine, diethylene glycol amine, N-methylethanolamine, N,N-dimethylethanolamine, triethylene glycol amine; the polyol is selected from one or more of ethylene glycol, propylene glycol, propylene glycol, butanediol, glycerol, glucose, xylitol, sorbitol, mannitol, inositol, pentaerythritol, maltitol, lactitol; 2. The etch residue removal composition according to claim 1, wherein the corrosion inhibitor is selected from the compounds represented by the following formula: R1(R2,R3,R4,R5,R6,R7) wherein R1 is a phenyl group, and R2-R7 are each independently H, an alkyl group, a hydroxyl group, an amino group, or a carboxyl group.

3. The etching residue removal composition according to claim 1, wherein the organic solvent is selected from one or more of isopropanol, butanol, butylene carbonate, ethylene carbonate, propylene carbonate, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPM), tripropylene glycol methyl ether (TPM), dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, N-methylpyrrolidone, N-ethylpyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide; 4. The etching residue removing composition according to claim 1, wherein the mass percentage content range of the organic base is 10 wt% - 80 wt%.

5. The etching residue removal composition according to claim 1, wherein the mass percentage content range of the corrosion inhibitor is 0.1 wt% - 15 wt%.

6. The etch residue removal composition according to claim 1, wherein the mass percentage content range of the organic solvent is 10 wt% - 70 wt%.

7. The etch residue removal composition according to claim 1, wherein the mass percentage content range of the polyol is 0.1 wt% - 5 wt%.

8. The etching residue removal composition according to claim 1, wherein the pH value is 8 - 13.

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