Composition for removing etching residue

Abstract

Provided is a composition for removing etching residue, comprising: an organic solvent, a metal corrosion inhibitor, a chelating agent, an acid and water. The composition for removing etching residue can be used to remove residue after etching or ashing from the surface of a semiconductor substrate, as well as TiN or a mask composed of TiN on the surface of a semiconductor substrate after oxide etching or partial oxide etching. It has good cleaning ability for TiN, while having a low corrosion rate for metallic tungsten; the TiN / W etching rate selectivity ratio is greater than 10, and it has good compatibility with low-K materials. Moreover, the cleaning liquid composition has a large process operation window, and has broad application prospects in the field of semiconductor wafer cleaning.

Description

Composition for removing etching residues Technical Field

[0001] The present invention relates to the technical field of etching, in particular to a composition for removing etching residues. Background Art

[0002] Depending on the specific structure of the integrated circuit interconnects to be created on the semiconductor substrate, it may be necessary to selectively remove the TiN or a layer or mask consisting of TiN completely or partially in the presence of other materials, in particular tungsten and / or low-k materials, with high precision, while at the same time not affecting or damaging the other materials present, in particular tungsten and / or low-k materials, or affecting or damaging them as little as possible.

[0003] Existing composite technologies for removing etch residues often suffer from insufficient removal of TiN hardmasks and inadequately suppressing damage to tungsten materials. If etch residues are not effectively removed from the substrate, they can interfere with subsequent processes involving the substrate. Poor removal or cleaning can result in low reliability and / or performance of semiconductor devices. Improper cleaning can also expose the surface of semiconductor wafers to air during processing, limiting process flexibility. Summary of the Invention

[0004] In order to overcome the above technical deficiencies, the present invention aims to provide a composition for removing etching residues, characterized in that it comprises: an organic solvent, a metal corrosion inhibitor, a chelating agent, an acid and water.

[0005] Preferably, the organic solvent is selected from one or more of sulfolane, dimethyl sulfoxide, dimethylacetamide, formylmorpholine, ethanol, ethylene glycol, n-propanol, isopropanol, 1,2-propylene glycol, 1,3-propylene glycol, n-butanol, n-hexanol, benzyl alcohol, tetrahydrofurfuryl alcohol, 3-methoxybutanol, N-methylpyrrolidone, 1,4-dioxane, dipropylene glycol, propylene glycol methyl ether, tripropylene glycol methyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, and diglycolamine.

[0006] Preferably, the mass percentage content of the organic solvent is 10% to 70%.

[0007] Preferably, the metal corrosion inhibitor is selected from imidazole, benzimidazole, 2-methylbenzimidazole, mercaptoimidazole, methimazole, 1-hydroxybenzotriazole, benzotriazole, methylbenzotriazole, 1,2,4-triazole, 3-amino-5-mercapto-1,2,4-triazole, 5-benzylthiotetrazole, 5-phenyltetrazole, fructose, benzamide, benzoylhydrazine, ethanolhydrazine, methylguanamine, succinimide, benzyldodecyldimethylammonium chloride, benzylhexadecyldimethylammonium chloride, hexamethylenetetramine, 2-amino-5-mercapto-1,3,4-thiadiazole, 2,4-diamino-6- One or more of diallylamino-1,3,5-triazine, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5-triazine, 2-aminophenol, pyrazine, pyrazole, 1-methylpyrazole, uracil, hydroxylamine sulfate, glycine, lysine, glutamic acid, proline, tyrosine, serine, L-cystine, L-cysteine, DL-methionine, L-phenylalanine, 3-aminobenzoic acid, phthalic acid, tetraethylthiuram disulfide, ammonium tartrate, ammonium acetate, acetylpyrrole, ammonium fluoride, ammonium benzoate, ammonium dihydrogen phosphate, saccharin, cinnamic acid, and urea.

[0008] Preferably, the mass percentage content of the metal corrosion inhibitor is 0.01% to 5%.

[0009] Preferably, the chelating agent is selected from one or more of iminodiacetic acid, cycloethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, hydroxyethylidene diphosphonic acid, (1-hydroxyethylidene) diphosphonic acid, tris(hydroxymethyl)methylglycine, phosphonic acid H66, phosphonic acid JP-504, phosphonic acid JP-506, and phosphonic acid JP-508.

[0010] Preferably, the mass percentage content of the chelating agent is 0.01% to 5%.

[0011] Preferably, the acid is selected from one or more of sulfamic acid, 1-naphthylamine-6-sulfonic acid, formamidinesulfinic acid, methanesulfonic acid, benzoic acid, glycolic acid, sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, tetrafluoroboric acid, hexafluorosilicic acid, hydrofluoric acid, and oxalic acid.

[0012] Preferably, the mass percentage content of the acid is 0.1% to 10%.

[0013] Preferably, the composition of the etching residue further comprises hydrogen peroxide.

[0014] Preferably, the mass percentage content of the hydrogen peroxide is 0.5% to 5%.

[0015] Compared with the existing technology, the above technical solution has the following beneficial effects:

[0016] In the presence of a metal layer or metal line, preferably tungsten, the composition of the present invention, when combined with one or more oxidizing agents, can be used to remove etching or ashing residues from the surface of a semiconductor substrate, as well as to oxidatively etch or partially oxidatively etch TiN or a TiN mask on the semiconductor substrate surface. It exhibits excellent cleaning performance for TiN while exhibiting a low etching rate for tungsten, with a TiN / W etching rate selectivity greater than 10, and excellent compatibility with low-K materials. Furthermore, the composition cleaning solution of the present invention has a wide process window and holds broad application prospects in the field of semiconductor wafer cleaning. DETAILED DESCRIPTION

[0017] The advantages of the present invention are further described below with reference to specific embodiments.

[0018] Effect embodiment 1:

[0019] During the preparation process, the components were directly mixed evenly. The compositions for removing etching residues in Examples 1-4 and Comparative Examples 1-6 of the present invention were prepared using the specific combinations and contents shown in Table 1. The contents in the table are all in mass percentage.

[0020] Table 1 Composition formula of Examples 1-4 and Comparative Examples 1-6

[0021] To investigate the compatibility of the composition with various materials, the etch rates of metals W and TiN, and non-metals TEOS and BDI were tested. The metal etch rate test method is as follows: W and TiN blank wafers were sliced ​​into 5x5cm pieces and placed in a single-wafer spin-cleaner for 3-20 minutes, preferably 10 minutes, at a rotation speed of 200-700 rpm, preferably 400 rpm, and at a test temperature of 25-70°C, preferably 60°C. After treatment, the wafers were removed from the machine, rinsed with deionized water, and then dried with high-purity nitrogen.

[0022] The etching rate test method is as follows:

[0023] 1) Use a metal film thickness gauge to measure the resistance (R1) of a 5*5cm metal blank wafer to be tested;

[0024] 2) Place the 5*5cm metal blank wafer to be tested in a single-wafer spin cleaning machine for processing;

[0025] 3) Take out the 5*5cm metal blank wafer, rinse it with deionized water, blow dry it with high-purity nitrogen, and then use a metal film thickness gauge to measure the resistance (R2) of the metal blank wafer;

[0026] 4) By inputting the above resistance value change and processing time into the appropriate program, the etching rate can be calculated. The calculation formula is as follows:

[0027] ER=K(R2-R1) / T

[0028] Among them, R1 and R2 are the resistance values ​​of the metal blank wafer; T is the processing time of the single chip microcomputer; K value is the coefficient, and the K value of different metal materials is different. The unit of metal corrosion rate is

[0029] The etching rate test method for non-metallic materials (TEOS, BDⅠ) is as follows:

[0030] 1) Using an ellipsometer to measure the first thickness D1 of the non-metallic material layer (e.g., BDⅠ) of a 5*5cm non-metallic blank wafer to be tested;

[0031] 2) Place the 5*5cm non-metallic blank wafer to be tested in a single wafer spin cleaning machine for processing for a time of T and a rotation speed of 400 rpm;

[0032] 3) Take out the blank wafer, rinse it with deionized water, blow dry it with high-purity nitrogen, and then use an ellipsometer to measure the second thickness D2;

[0033] 4) By substituting the above thickness change and treatment time into the formula, the corrosion rate can be calculated. The calculation formula is as follows: ER = (D1-D2) / T

[0034] D1 and D2 are the first thickness and the second thickness of the non-metal blank wafer respectively; T is the processing time.

[0035] Table 2 Etching test results of Examples 1-4 and Comparative Examples 1-6

[0036] Based on the test results of Examples 1-4 and Comparative Examples 1-6 in Table 2, it can be seen that the addition of the solvent diethylene glycol monobutyl ether effectively reduces the etching rate of metal W, while also enabling the composition to have a certain degree of cleaning ability for TiN, and also reducing the etching rate of non-metals. Furthermore, the composition of the present invention exhibits good compatibility with all four materials at different rotation speeds and operating times.

[0037] Effect embodiment 2:

[0038] During the preparation process, the components were directly mixed evenly. The compositions for removing etching residues in Examples 5-9 and Comparative Examples 7-11 of the present invention were prepared using the specific combinations and contents shown in Table 3. The contents in the table are all in mass percentage.

[0039] Table 3 Components and contents of etching residues removed in Examples 5-9 and Comparative Examples 7-11

[0040] The compatibility of the etching residue removal compositions of Examples 5-9 and Comparative Examples 7-11 with various materials was further tested. The etching rates of the compositions on metal W and TiN, and non-metal TEOS and BDI were tested. The testing methods are the same as those described in Example 1 and are not further described here. The test results are shown in Table 4.

[0041] Table 4 Etching test results of Examples 5-9 and Comparative Examples 7-11

[0042] Based on the data shown in Table 4, it can be seen that the metal corrosion inhibitor hydroxylamine sulfate can effectively inhibit damage to tungsten or tungsten alloys, reduce the W etching rate, and can also etch TiN to a certain extent. In this case, the etching rate of non-metals is also low. Compositions using other types of metal corrosion inhibitors are obviously less compatible with W and TiN.

[0043] Effect embodiment three:

[0044] During the preparation process, the components were directly mixed uniformly. The compositions for removing etching residues in Examples 10-14 of the present invention and Comparative Examples 12-16 were prepared using the specific combinations and contents shown in Table 5. The contents in the table are all in mass percentage.

[0045] Table 5 Components and contents of etching residues removed in Examples 10 to 14 of the present invention and Comparative Examples 12 to 16

[0046] The compatibility of the etching residue removal compositions of Examples 10-14 and Comparative Examples 12-16 with various materials was further tested. The etching rates of the compositions on metal W and TiN, and non-metal TEOS and BDI were tested. The testing methods are the same as those described in Example 1 and are not further described here. The test results are shown in Table 6.

[0047] Table 6 Etching test results of Examples 10 to 14 of the present invention and Comparative Examples 12 to 16

[0048] Based on the test data of Examples 10 to 14 and Comparative Examples 12 to 16 in Table 6, it can be seen that adding one of the various chelating agents to the original metal corrosion inhibitor can simultaneously reduce the etching rate of W and TiN, and also make the etching rate of non-metals even lower.

[0049] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A composition for removing etching residues, characterized in that include: Organic solvents, metal corrosion inhibitors, chelating agents, acids and water.

2. The composition for removing etching residues according to claim 1, wherein The organic solvent is selected from one or more of sulfolane, dimethyl sulfoxide, dimethylacetamide, formylmorpholine, ethanol, ethylene glycol, n-propanol, isopropanol, 1,2-propylene glycol, 1,3-propylene glycol, n-butanol, n-hexanol, benzyl alcohol, tetrahydrofurfuryl alcohol, 3-methoxybutanol, N-methylpyrrolidone, 1,4-dioxane, dipropylene glycol, propylene glycol methyl ether, tripropylene glycol methyl ether, ethylene glycol monobutyl ether, diethylene glycol dimethyl ether, and diglycolamine.

3. The composition for removing etching residues according to claim 1, wherein The mass percentage content of the organic solvent is 10% to 70%.

4. The composition for removing etching residues according to claim 1, wherein The metal corrosion inhibitor is selected from imidazole, benzimidazole, 2-methylbenzimidazole, mercaptoimidazole, methimazole, pyrazine, pyrazole, 1-methylpyrazole, 1-hydroxybenzotriazole, benzotriazole, methylbenzotriazole, 1,2,4-triazole, 3-amino-5-mercapto-1,2,4-triazole, 5-benzylthiotetrazole, 5-phenyltetrazole, 2-amino-5-mercapto-1,3,4-thiadiazole, 2,4-diamino-6-diallylamino-1,3,5-triazine, 2,4-diamino-6-[2-(2-methyl-1-imidazolyl)ethyl]-1,3,5- One or more of triazine, uracil, acetylpyrrole, glycine, lysine, glutamic acid, proline, tyrosine, serine, L-cystine, L-cysteine, DL-methionine, L-phenylalanine, 3-aminobenzoic acid, benzamide, methylguanamine, succinimide, hexamethylenetetramine, saccharin, hydroxylamine sulfate, fructose, benzoylhydrazide, ethanolhydrazine, benzyldodecyldimethylammonium chloride, benzylhexadecyldimethylammonium chloride, 2-aminophenol, phthalic acid, tetraethylthiuram disulfide, ammonium tartrate, ammonium acetate, ammonium fluoride, ammonium benzoate, diammonium phosphate, cinnamic acid, and urea.

5. The composition for removing etching residues according to claim 1, characterized in that The mass percentage content of the metal corrosion inhibitor is 0.01% to 5%.

6. The composition for removing etching residues according to claim 1, characterized in that The chelating agent is selected from one or more of iminodiacetic acid, cycloethylenediaminetetraacetic acid, ethylenediaminetetraacetic acid, diethyltriaminepentaacetic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, hydroxyethylidene diphosphonic acid, (1-hydroxyethylidene) diphosphonic acid, tris(hydroxymethyl)methylglycine, phosphonic acid H66, phosphonic acid JP-504, phosphonic acid JP-506, and phosphonic acid JP-508.

7. The composition for removing etching residues according to claim 1, wherein The mass percentage content of the chelating agent is 0.01% to 5%.

8. The composition for removing etching residues according to claim 1, wherein The acid is selected from one or more of sulfamic acid, 1-naphthylamine-6-sulfonic acid, formamidinesulfinic acid, methanesulfonic acid, benzoic acid, glycolic acid, sulfuric acid, phosphoric acid, nitric acid, hydrochloric acid, tetrafluoroboric acid, hexafluorosilicic acid, hydrofluoric acid, and oxalic acid.

9. The composition for removing etching residues according to claim 1, wherein The mass percentage content of the acid is 0.1% to 10%.

10. The composition for removing etching residues according to claim 1, wherein The etch residue composition also includes hydrogen peroxide.

11. The composition for removing etching residues according to claim 10, characterized in that The mass percentage content of the hydrogen peroxide is 0.5% to 5%.

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