Composition for removing etching residues

Abstract

The invention provides a composition for removing etching residues. The composition comprises an organic solvent, a metal corrosion inhibitor, a chelating agent, acid and water. The composition for removing the etching residues can be used for removing the residues after etching or ashing from the surface of a semiconductor substrate and performing oxidation etching or partial oxidation etching on TiN or a mask composed of TiN on the surface of the semiconductor substrate. Compared with the prior art, the cleaning agent has the advantages that the cleaning agent has good cleaning capacity for TiN, meanwhile, the cleaning agent has a small corrosion rate for metal tungsten, the TiN / W etching rate selection ratio is larger than 10, and the cleaning agent has good compatibility for low-K materials. And the composition cleaning liquid has a large process operation window, and has a wide application prospect in the field of semiconductor wafer cleaning.

Description

Technical Field

[0001] The present invention relates to the field of etching technology, and particularly to a composition for removing etching residues. Background Art

[0002] According to the specific structure of the integrated circuit interconnects to be created on a semiconductor substrate, it may be necessary to selectively and completely or partially remove TiN or a layer or mask composed of TiN with high precision in the presence of other materials, especially in the presence of tungsten materials and / or low-k materials. At the same time, other existing materials, especially tungsten materials and / or low-k materials, cannot be affected or damaged, or are affected or damaged to the minimum extent possible.

[0003] However, in the existing composition technology for removing etching residues, there are often problems such as insufficient removability of the TiN hard mask and inability to sufficiently inhibit damage to tungsten materials. If the etching residues are not effectively removed from the substrate, they may interfere with subsequent processes involving the substrate. The consequences of poor removal or cleaning will lead to low reliability and / or low performance of semiconductor devices. Improper cleaning will also expose the surface of the semiconductor wafer to air during processing, thus causing limitations in process flexibility. Summary of the Invention

[0004] In order to overcome the above technical defects, the object of the present invention is to provide a composition for removing etching residues, which is characterized by comprising: 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-propanediol, 1,3-propanediol, 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 diethanolamine.

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

[0007] Preferably, the metal corrosion inhibitor is selected from one or more of 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, benzohydrazide, ethanol hydrazide, methylguanamine, succinimide, benzyl dodecyldimethylammonium chloride, benzyl hexadecyldimethylammonium chloride, hexamethylenetetramine, 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-triazine, 2-aminophenol, pyrazine, pyrazole, 1-methylpyrazole, uracil, hydroxylamine sulfate, glycine, lysine, glutamic acid, proline, tyrosine, serine, L-cysteine, L-cystine, 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, urea.

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

[0009] Preferably, the chelating agent is selected from one or more of iminodiacetic acid, cyclohexanediaminetetraacetic 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, phosphonic acid JP-508.

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

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

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

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

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

[0015] After adopting the above technical solution, compared with the prior art, it has the following beneficial effects:

[0016] In the presence of a metal layer or metal wire preferably made of tungsten, when the composition in the present invention is combined with one or more oxidants, it can be used to remove the residues after etching or ashing from the surface of a semiconductor substrate, and to oxidize etch or partially oxidize etch the TiN on the surface of the semiconductor substrate or the mask composed of TiN. It has good cleaning ability for TiN, while having a relatively low corrosion rate for metal tungsten. The etching rate selectivity ratio of TiN / W is greater than 10, and it has good compatibility with low-K materials. Moreover, the cleaning solution process operation window of the composition in the present invention is large, and it has broad application prospects in the field of semiconductor wafer cleaning. Detailed implementation mode

[0017] The advantages of the present invention are further elaborated below in conjunction with specific embodiments.

[0018] Effect example 1:

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

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

[0021]

[0022] In order to investigate the compatibility of the composition with various materials, the etching rates of metal W, TiN, and non-metals TEOS and BDⅠ were tested. The test method for the metal etching rate is as follows: Select W and TiN blank wafers, cut the blank wafers into pieces of 5*5 cm in size, place them under a single-wafer spin cleaner for treatment, the treatment time range is 3-20 min, preferably 10 min, the rotation speed setting range is 200-700 rpm, preferably 400 rpm, the test temperature is 25-70 °C, preferably 60 °C. After the treatment, take out, rinse with deionized water and then dry with high-purity nitrogen.

[0023] The etching rate test method is as follows:

[0024] 1) Use a metal thin film thickness gauge to measure the resistance (R1) of a 5*5 cm metal blank wafer to be tested;

[0025] 2) Place the 5*5 cm metal blank wafer to be tested under a single-wafer spin cleaner for treatment;

[0026] 3) Take out the 5*5 cm metal blank wafer, clean it with deionized water, dry it with high-purity nitrogen, and then use a metal thin film thickness gauge to measure the resistance (R2) of the metal blank wafer;

[0027] 4) By inputting the above-mentioned change in resistance value and processing time into a suitable program, the etching rate can be calculated. The calculation formula is as follows:

[0028] ER = K(R2 - R1)T

[0029] Among them, R1 and R2 are the resistance values of the metal blank wafer; T is the processing time of the single-chip microcomputer; the value of K is a coefficient, and the K values of different metal materials are different. The unit of the metal corrosion rate is

[0030] The test method for the etching rate of non-metallic materials (TEOS, BDⅠ) is as follows:

[0031] 1) Use an ellipsometer to measure the first thickness D1 of the non-metallic material layer (such as BDⅠ) of the 5*5 cm non-metallic blank wafer to be measured;

[0032] 2) Place the 5*5 cm non-metallic blank wafer to be measured in a single-chip rotary cleaning machine for processing for a time of T, and set the rotation speed to 400 rpm;

[0033] 3) Take out the blank wafer, wash it with deionized water, then dry it with high-purity nitrogen, and then use an ellipsometer to measure the second thickness D2;

[0034] 4) By substituting the above-mentioned change in thickness value and processing time into the formula, the corrosion rate can be calculated. The calculation formula is as follows:

[0035] ER = (D1 - D2) / T

[0036] D1 and D2 are the first thickness and the second thickness of the non-metallic blank wafer respectively; T is the processing time.

[0037] Table 2 Etching test results of Examples 1-4 and Comparative Examples 1-6

[0038]

[0039] Based on the test results of Examples 1 to 4 and Comparative Examples 1 to 6 in Table 2, it can be seen that the addition of the solvent diethylene glycol monobutyl ether can effectively reduce the etching rate of metal W, and at the same time, the composition can also have a certain degree of cleaning ability for TiN, and the etching rate of non-metals is also relatively low. Moreover, the composition in the present invention has good compatibility with the four materials under different rotation speeds and operation times.

[0040] Effect Example Two:

[0041] During the preparation process, directly mix each component evenly. Prepare the composition for removing etching residues in Examples 5-9 and Comparative Examples 7-11 of the present invention with the specific combinations and their contents shown in Table 3. The contents in the table are all mass percentage contents.

[0042] Table 3 Components and their contents for removing etching residues in Examples 5-9 and Comparative Examples 7-11

[0043]

[0044] The compatibility of the compositions for removing etching residues in the above Examples 5-9 and Comparative Examples 7-11 with various materials was further tested. The etching rates of the compositions for metals W and TiN, and non-metals TEOS and BDI were tested respectively. The testing method is as described in Effect Example 1 and will not be elaborated here. The test results are shown in Table 4.

[0045] Table 4 Etching test results of Examples 5-9 and Comparative Examples 7-11

[0046]

[0047] Based on the data shown in Table 4, it can be known that the metal corrosion inhibitor hydroxylamine sulfate can effectively inhibit the damage of tungsten or tungsten alloy, reduce the W etching rate, and can also etch TiN to a certain extent. At this time, the etching rate of non-metals is also relatively low. The compositions using other types of metal corrosion inhibitors are significantly poor in compatibility with W and TiN.

[0048] Effect Example Three:

[0049] During the preparation process, each component was directly mixed evenly. The compositions for removing etching residues in Examples 10-14 and Comparative Examples 12-16 of the present invention were prepared with the specific combinations and their contents shown in Table 5. The contents in the table are all mass percentage contents.

[0050] Table 5 Components and their contents for removing etching residues in Examples 10-14 and Comparative Examples 12-16 of the present invention

[0051]

[0052]

[0053] The compatibility of the compositions for removing etching residues in the above Examples 10-14 and Comparative Examples 12-16 with various materials was further tested. The etching rates of the compositions for metals W and TiN, and non-metals TEOS and BDI were tested respectively. The testing method is as described in Effect Example 1 and will not be elaborated here. The test results are shown in Table 6.

[0054] Table 6 Etching test results of Examples 10-14 and Comparative Examples 12-16 of the present invention

[0055]

[0056] Based on the test data of Examples 10 to 14 and Comparative Examples 12 to 16 in Table 6, it can be seen that on the basis of the original metal corrosion inhibitor, adding one of a variety of chelating agents can simultaneously reduce the etching rates of W and TiN and also make the etching rate of non-metals lower.

[0057] It should be noted that the embodiments of the present invention have good implementability and do not limit the present invention in any form. Any person skilled in the art may use the technical content disclosed above to change or modify it into equivalent effective embodiments. However, as long as it does not depart from the technical solution 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. A composition for removing etching residues, characterized in that, Comprising: an organic solvent, a metal corrosion inhibitor, a chelating agent, an acid, and water.

2. The composition for removing etching residues according to claim 1, characterized in that the organic solvent is selected from one or more of sulfolane, dimethyl sulfoxide, dimethylacetamide, formylmorpholine, ethanol, ethylene glycol, n-propanol, isopropanol, 1,2-propanediol, 1,3-propanediol, 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 diethanolamine.

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

4. The composition for removing etching residues according to claim 1, characterized in that the metal corrosion inhibitor is selected from one or more of imidazole, benzimidazole, 2-methylbenzimidazole, mercaptoimidazole, methylmercaptoimidazole, 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-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, benzoylhydrazine, ethanol hydrazine, benzyl dodecyldimethylammonium chloride, benzyl hexadecyldimethylammonium chloride, 2-aminophenol, phthalic acid, tetraethylthiuram disulfide, ammonium tartrate, ammonium acetate, ammonium fluoride, ammonium benzoate, ammonium dihydrogen 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, cyclohexanediaminetetraacetic 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.

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

8. The composition for removing etching residues according to claim 1, characterized in that The acid is selected from one or more of sulfamic acid, 1-naphthylamine-6-sulfonic acid, formamidine sulfinic 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 composition for removing etching residues further comprises hydrogen peroxide.

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

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