Composition for removing residues after etching

Abstract

The invention provides a composition compatible with metal oxides and used for removing residues after etching through a wet method, and particularly relates to a semi-aqueous composition compatible with zirconium oxide and aluminum oxide. The composition comprises an organic solvent, fluoride, a corrosion inhibitor and water, and a chelating agent and a pH regulator can be selectively added. The composition has outstanding compatibility with zirconium oxide, aluminum oxide and other metal oxides on the basis of guaranteeing the removal of etching residues, the stability of an integrated circuit is finally guaranteed, the yield of a semiconductor device is improved, meanwhile, particles are prevented from being formed on a substrate, the operation condition is mild (the composition can be used at 20-50 DEG C), and the application range is wide. The pH application range is wide (the pH value is 6-9, preferably 6.5-8), and the cleaning agent has a good application prospect in the field of high-end semiconductor cleaning.

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 semiconductor manufacturing process, the high-temperature stability of zirconia makes it an ideal material for electronic devices in high-temperature environments. In high-temperature environments, traditional semiconductor materials are prone to degradation or failure, while zirconia semiconductors have a high melting point and thermal stability, and can maintain stable electrical properties in high-temperature environments. In addition, zirconia has excellent electrical properties, with high electrical conductivity and low resistivity, and can provide efficient electron transport and energy conversion in electronic devices. Furthermore, zirconia also has good carrier mobility characteristics and low carrier loss, enabling electronic devices to work more stably and efficiently. Therefore, zirconia is widely used in fields such as integrated circuits, optoelectronic devices, and power electronic devices.

[0003] Aluminum oxide has very excellent insulation properties, can effectively prevent leakage and short-circuit problems between electronic components, ensure the normal operation of electronic components, and thus improve the reliability and safety of electronic devices. Aluminum oxide can be used as an isolation layer and dielectric layer for integrated circuits to ensure the performance and reliability of integrated circuits.

[0004] In more and more advanced chip manufacturing processes, the challenges to the manufacturing process are also increasing. An ideal remover needs to have an etching rate for the residues after etching that is much greater than that for other layers. The disclosure of the present invention provides a composition for removing residues after etching, which can be compatible with metal oxides such as zirconia and aluminum oxide, ultimately ensuring the stability of integrated circuits, improving the yield of semiconductor devices, and also avoiding the formation of particles on the substrate. The operating conditions are mild (it can be used at 20°C to 50°C), and it has good application prospects in the field of high-end semiconductor cleaning. Summary of the Invention

[0005] The present invention provides a composition for removing residues after etching that is compatible with zirconia and aluminum oxide. The composition includes an organic solvent, a fluoride, a corrosion inhibitor, and water, and a chelating agent and a pH regulator can also be selectively added. This composition can have outstanding compatibility with metals, metal oxides, metal nitrides, and dielectrics, remove etching residues without damaging the underlying film, has a fast removal rate, mild operating conditions (it can be used at 20°C to 50°C), and has broad application prospects in the cleaning field of semiconductor manufacturing.

[0006] The present invention discloses a composition for removing residues after etching, including: an organic solvent; a fluoride; a corrosion inhibitor; water.

[0007] Further, the organic solvent is selected from one or more of alcohols, alcohol ethers, amines, alkanolamines, sulfones or sulfoxides, and amides.

[0008] Further, the alcohols include: methanol, ethanol, ethylene glycol, glycerol, 1,2 - propylene glycol, 1,3 - propylene glycol, n - propanol, isopropanol, n - butanol, isobutanol, benzyl alcohol, phenethyl alcohol, tetrahydrofurfuryl alcohol, preferably 1,3 - propylene glycol and n - butanol; the alcohol ethers include: propylene glycol methyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol phenyl ether, methyl tert - butyl ether, preferably ethylene glycol butyl ether and dipropylene glycol methyl ether; the amines include: monoethylamine, diethylamine, triethylamine, tripropylamine, N,N'-diethylethylenediamine, hydroxyethyl ethylenediamine, cyclohexylamine, 1,2 - propanediamine, pentamethyldiethylenetriamine; the alkanolamines include: monoethanolamine, diethanolamine, triethanolamine, diethylene glycol amine, n - propanolamine, isopropanolamine, N - methylethanolamine; the sulfones or sulfoxides include: dimethyl sulfone, dimethyl sulfoxide, diethyl sulfoxide, diphenyl sulfoxide, sulfolane, preferably dimethyl sulfoxide and sulfolane; the amides include: N - methylformamide, dimethylformamide, N - methylacetamide, dimethylacetamide, 1 - methyl - 2 - pyrrolidone, 2 - pyrrolidone, preferably dimethylformamide, dimethylacetamide and 1 - methyl - 2 - pyrrolidone.

[0009] Further, the fluorides include: hydrogen fluoride, ammonium fluoride, ammonium bifluoride, ammonium fluoroborate, fluoroboric acid, fluorosilicic acid, ammonium fluorosilicate, fluotitanic acid, ammonium fluotitanate, fluozirconic acid, tetraalkylammonium fluoride, tetramethylammonium hexafluorophosphate, etc.

[0010] Further, the tetraalkylammonium fluoride contains one or more of tetramethylammonium fluoride, tetraethylammonium fluoride, tetrabutylammonium fluoride.

[0011] Further, the corrosion inhibitor includes one or more of organic acid ammonium salts, alkyl quaternary ammonium compounds, and azole heterocyclic compounds.

[0012] Further, the ammonium organic acid salt includes one or more of ammonium formate, ammonium oxalate, ammonium lactate, ammonium tartrate, ammonium citrate, diammonium citrate, ammonium acetate, ammonium carbamate, ammonium carbonate, ammonium benzoate, tetraammonium ethylenediaminetetraacetate, triammonium ethylenediaminetetraacetate, diammonium ethylenediaminetetraacetate, ammonium succinate, ammonium 1-H-pyrazole-3-carboxylate, ammonium malonate, ammonium adipate, ammonium iminodiacetate, ammonium nitrilotriacetate; the alkyl quaternary ammonium compound includes one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide or benzyltrimethylammonium hydroxide, preferably tetramethylammonium hydroxide; the azole heterocyclic compound includes one or more of benzotriazole, 1,2,4-triazole, 5-methylbenzotriazole, hydroxybenzotriazole, pyrazole, tolyltriazole, 3,5-dimethylpyrazole, tetrazole, 4-amino-1,2,4-triazole, benzothiazole, methyl-1H-benzotriazole, 2-aminobenzothiazole, 2-mercaptobenzothiazole, 3-amino-5-hydroxypyrazole, 1-phenylpyrazole, mercaptobenzimidazole, 5-aminotetrazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, 2-(5-aminopentyl)-benzotriazole, 5-phenylthiol-benzotriazole, methyltetrazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 1-amino-1,2,3-benzotriazole, thiazole.

[0013] Further, the composition for removing residues after etching further includes a pH regulator, and the pH regulator is selected from one or more of inorganic acids, organic acids, and basic compounds.

[0014] Further, the inorganic acid is selected from one or more of nitric acid, hydrochloric acid, sulfuric acid, boric acid, pyrosulfuric acid, phosphoric acid, pyrophosphoric acid, hydrobromic acid, perchloric acid, perbromic acid, periodic acid, orthoperiodic acid, selenic acid; the organic acid is selected from one or more of benzoic acid, acetic acid, carbonic acid, citric acid, malic acid, oxalic acid, lactic acid, tartaric acid, salicylic acid, gluconic acid, nicotinic acid; the basic compound is selected from one or more of urea and ammonia water; the acid is preferably sulfuric acid, acetic acid, citric acid, tartaric acid, and the basic compound is preferably urea.

[0015] Further, the composition for removing residues after etching further comprises a chelating agent, and the chelating agent includes one or more of glycine, serine, proline, leucine, alanine, aspartic acid, asparagine, glutamine, valine, lysine, cystine, ethylenediaminetetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, uric acid, picolinic acid, hydroxyethylidene diphosphonic acid, ethylenediamine tetramethylene phosphonic acid, hexamethylenediamine tetramethylene phosphonic acid, ethylenediamine-N,N'-disuccinic acid, glutamic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, ethylene glycol tetraacetic acid, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N''-tetraacetic acid, ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid), and propylenediaminetetraacetic acid.

[0016] Further, the mass percentage content range of the organic solvent is 30 wt% - 60 wt%; the mass percentage content range of the fluoride is 0.1 wt% - 5 wt%; the mass percentage content range of the corrosion inhibitor is 1 wt% - 25 wt%; the mass percentage content range of the water is 20 wt% - 50 wt%.

[0017] Further, the mass percentage content range of the organic solvent is 35% - 55%; the mass percentage content range of the fluoride is 0.5 wt% - 3 wt%; the mass percentage content range of the corrosion inhibitor is 5 wt% - 20 wt%; the mass percentage content range of the water is 30 wt% - 45 wt%.

[0018] Further, a pH regulator can be optionally added, and the mass percentage content range of the pH regulator is 0.1 wt% - 10 wt%, preferably the mass percentage content range is 1 wt% - 5 wt%.

[0019] Further, a chelating agent can be optionally added, and the mass percentage content range of the chelating agent is 0.01 wt% - 5 wt%, preferably the mass percentage content range is 0.1 wt% - 3 wt%.

[0020] Further, the pH value of the composition for removing residues after etching is 6 - 9, preferably 6.5 - 8.

[0021] The positive and progressive effects of the present invention are as follows: The present invention discloses a composition for removing residues after etching, which has outstanding compatibility with metal oxides such as zirconia and alumina, ultimately ensuring the stability of integrated circuits, improving the yield of semiconductor devices, avoiding the formation of particles on the substrate, having mild operating conditions (usable at 20°C - 50°C), a wide pH application range (pH value is 6 - 9, preferably 6.5 - 8), and having good application prospects in the field of high-end semiconductor cleaning. Detailed Description of the Invention

[0022] The following describes in detail the composition for removing residues after etching of the present invention through specific examples to better understand the present invention, but the following examples do not limit the scope of the present invention.

[0023] Prepare the cleaning compositions of Examples 1 - 19 and Comparative Examples 1 - 7 according to the components and contents described in Table 1. The ammonia water used is 28 wt%.

[0024] Table 1 Formulations of Examples 1 - 19 and Comparative Examples 1 - 7 (the % refers to mass percentage)

[0025]

[0026]

[0027]

[0028] Select some examples and comparative examples for performance testing:

[0029] (1) The test methods for the etching rates of alumina, zirconia, and titanium nitride are as follows:

[0030] Etching rate of alumina Place the cleaning solution on a mini - SWT (mini - single - chip microcomputer) machine table and heat it to the operating temperature (20°C - 50°C), then place the alumina wafer in it and clean for 5 min, and then calculate the etching rate by measuring the thickness change before and after cleaning with an ellipsometer.

[0031] Etching rate of zirconia Place the cleaning solution on a mini - SWT (mini - single - chip microcomputer) machine table and heat it to the operating temperature (20°C - 50°C), then place the zirconia wafer in it and clean for 5 min, and then calculate the etching rate by measuring the thickness change before and after cleaning with an ellipsometer.

[0032] Etching rate of titanium nitride Place the cleaning composition on the mini-SWT (mini single-chip microcomputer) platform and heat it to the operating temperature (20°C - 50°C). Then place the titanium nitride wafer in it and clean for 5 minutes. Then measure the change in the resistance value (Rs) of the wafer before and after cleaning through a Napson four-point probe to calculate the etching rate.

[0033] (2) Use an X-ray photoelectron spectroscopy analyzer (XPS) to test the adsorption of the composition on the wafer surface. Since the corrosion inhibitor contains N element, judge the adsorption of the composition on the wafer surface based on the content of N element on the wafer surface before and after.

[0034] (3) The cleaning result of the etching residue on the wafer surface by the composition can be observed through a Hitachi SU8220 scanning electron microscope (SEM).

[0035] Table 2 Etching rates and wafer cleaning results of Examples 1 - 19 and Comparative Examples 1 - 3

[0036]

[0037]

[0038] It can be seen from Table 2 that: The compositions of the present invention can basically remove the etching residues on the wafer. At the same time, they have particularly good compatibility with metal oxide layers such as alumina layer and zirconia layer. The etching rate operation window for the alumina layer is relatively large, and can be controllably adjusted, and can even be reduced to The etching rate for zirconia can also be achieved to or less. In addition, the results of all examples show that the compositions described in this patent also have good compatibility with TiN and basically do not corrode.

[0039] In addition, by comparing Example 16 with Comparative Example 1, and Example 12 with Comparative Example 2, it can be found that when the organic solvent or fluoride is removed from the composition, although the etching rate of the metal oxide is further reduced, it is very unfavorable for the cleaning of the etching residues on the wafer, and many residues appear. By comparing Example 9 with Comparative Example 3, it can be found that the role of the corrosion inhibitor in the present invention is very obvious, and the etching rates of metal oxides and metal nitrides can be suppressed to a very low level. The composition in the present invention can also contain a chelating agent. By comparing Example 13 and Example 14, the composition with an additional chelating agent can further protect the metal oxide.

[0040] Further study the relationship between the pH value of the composition and the solution stability, and the detailed results are shown in Table 3.

[0041] Generally speaking, the stability of the solution is a necessary condition, and pH regulators can be added according to specific circumstances: (1) When the pH value of the solution after mixing all other components except the pH regulator is between 6.5 and 8, it is not necessary to add an additional pH regulator, and the shelf life of the solution can be stable within 48 hours (the pH value remains basically unchanged). (2) When the pH value of the solution after mixing all other components except the pH regulator is outside the range of 6.5 - 8, it has little impact on the cleaning result of the wafer, mainly reducing the shelf life of the solution. Although it can also protect metal oxides at this time, it will affect the etching rate of alumina and the stability of the pH value. Therefore, in order to be more stable and extend the continuous use time of the solution, it is necessary to add a pH regulator in the formulation to adjust the pH value within the range of 6.5 - 8.

[0042] Table 3 Solution stability, etching rate, and wafer cleaning results of Example 4 and Comparative Example 4

[0043]

[0044]

[0045] It can be found from Comparative Example 4 and Example 4 that only by adding a pH regulator to adjust the pH to the preferred range (6.5 - 8), the composition can remain stable within 48 hours.

[0046] Table 4 Etching rates and cleaning results of Example 10 and Comparative Examples 5 - 7 at different temperatures

[0047]

[0048] It can be found from Example 10, Comparative Example 5, and Comparative Example 6 that the operating temperature of this composition is relatively mild and can be completed within 50°C. However, the temperature cannot be too low, otherwise the etching residues cannot be completely cleaned within the same time; the temperature is not recommended to be too high either. On the one hand, it wastes energy and increases the operation risk, and on the other hand, it will also increase the etching rate of metal oxides additionally. In addition, XPS was used to analyze the N element before and after wafer cleaning, and no increase in N content was observed, so it can be judged that the composition did not adsorb on the wafer surface.

[0049] In summary, the positive and progressive effects of the present invention are as follows: The present invention discloses a composition for removing post-etch residues, in particular a composition for wet-etching removal of post-etch residues that is compatible with metal oxides, and relates to a semi-aqueous composition that is compatible with zirconia and alumina. It has outstanding compatibility with metal oxides such as zirconia and alumina, ultimately ensuring the stability of integrated circuits, improving the yield of semiconductor devices, avoiding the formation of particles on the substrate, having mild operating conditions (usable at 20°C - 50°C), a wide pH application range (pH value of 6 - 9, preferably 6.5 - 8), and has good application prospects in the field of high-end semiconductor cleaning.

[0050] It should be noted that the embodiments of the present invention have good implementability and are not limited to any form of the present invention. 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 based on 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 residues after etching, characterized in that, Comprising: Organic solvent; Fluoride; Corrosion inhibitor; Water.

2. The composition for removing residues after etching according to claim 1, characterized in that, The organic solvent is selected from one or more of alcohols, alcohol ethers, amines, alkanolamines, sulfones or sulfoxides, and amides.

3. The composition for removing residues after etching according to claim 2, characterized in that, The alcohols include: methanol, ethanol, ethylene glycol, glycerol, 1,2 - propanediol, 1,3 - propanediol, n - propanol, isopropanol, n - butanol, isobutanol, benzyl alcohol, phenethyl alcohol, tetrahydrofurfuryl alcohol; The alcohol ethers include: propylene glycol methyl ether, ethylene glycol methyl ether, ethylene glycol butyl ether, diethylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol phenyl ether, methyl tert - butyl ether; The amines include: monoethylamine, diethylamine, triethylamine, tripropylamine, N,N'-diethylethylenediamine, hydroxyethyl ethylenediamine, cyclohexylamine, 1,2 - propanediamine, pentamethyldiethylenetriamine; The alkanolamines include: monoethanolamine, diethanolamine, triethanolamine, diethylene glycol amine, n - propanolamine, isopropanolamine, N - methylethanolamine; The sulfones or sulfoxides include: dimethyl sulfone, dimethyl sulfoxide, diethyl sulfoxide, diphenyl sulfoxide, sulfolane; The amides include: N - methylformamide, dimethylformamide, N - methylacetamide, dimethylacetamide, 1 - methyl - 2 - pyrrolidone, 2 - pyrrolidone.

4. The composition for removing residues after etching according to claim 1, characterized in that, The fluoride includes: one or more of hydrogen fluoride, ammonium fluoride, ammonium bifluoride, ammonium fluoroborate, fluoroboric acid, fluorosilicic acid, ammonium fluorosilicate, fluotitanic acid, ammonium fluotitanate, fluozirconic acid, tetraalkylammonium fluoride, tetramethylammonium hexafluorophosphate.

5. The composition for removing residues after etching according to claim 4, characterized in that, The tetraalkylammonium fluoride includes one or more of tetramethylammonium fluoride, tetraethylammonium fluoride, tetrabutylammonium fluoride.

6. The composition for removing residues after etching according to claim 1, characterized in that, The corrosion inhibitor includes one or more of organic acid ammonium salts, alkyl quaternary ammonium compounds, and azole heterocyclic compounds.

7. The composition for removing residues after etching according to claim 6, characterized in that, The organic acid ammonium salts include: one or more of ammonium formate, ammonium oxalate, ammonium lactate, ammonium tartrate, ammonium citrate, diammonium citrate, ammonium acetate, ammonium carbamate, ammonium carbonate, ammonium benzoate, tetraammonium ethylenediaminetetraacetate, triammonium ethylenediaminetetraacetate, diammonium ethylenediaminetetraacetate, ammonium succinate, ammonium 1 - H - pyrazole - 3 - carboxylate, ammonium malonate, ammonium adipate, ammonium iminodiacetate, nitrilotriacetic acid; The alkyl quaternary ammonium compounds include: one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide or benzyltrimethylammonium hydroxide; The azole heterocyclic compound includes one or more of: benzotriazole, 1,2,4-triazole, 5-methylbenzotriazole, hydroxybenzotriazole, pyrazole, tolyltriazole, 3,5-dimethylpyrazole, tetrazole, 4-amino-1,2,4-triazole, benzothiazole, methyl-1H-benzotriazole, 2-aminobenzothiazole, 2-mercaptobenzothiazole, 3-amino-5-hydroxypyrazole, 1-phenylpyrazole, mercaptobenzimidazole, 5-aminotetrazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, 2-(5-aminopentyl)-benzotriazole, 5-phenylthiol-benzotriazole, methyltetrazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 1-amino-1,2,3-benzotriazole, thiazole.

8. The composition for removing residues after etching according to claim 1, characterized in that, It includes a pH regulator, and the pH regulator is selected from one or more of: inorganic acids, organic acids, and basic compounds.

9. The composition for removing residues after etching according to claim 8, characterized in that, The inorganic acid is selected from one or more of: nitric acid, hydrochloric acid, sulfuric acid, boric acid, pyrosulfuric acid, phosphoric acid, pyrophosphoric acid, hydrobromic acid, perchloric acid, perbromic acid, periodic acid, metaperiodic acid, selenic acid; the organic acid is selected from one or more of: benzoic acid, acetic acid, carbonic acid, citric acid, malic acid, oxalic acid, lactic acid, tartaric acid, salicylic acid, gluconic acid, nicotinic acid; the basic compound is selected from one or more of: urea, ammonia water.

10. The composition for removing residues after etching according to claim 1, characterized in that, It includes a chelating agent, and the chelating agent includes: glycine, serine, proline, leucine, alanine, aspartic acid, asparagine, glutamine, valine, lysine, cystine, ethylenediaminetetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, uric acid, picolinic acid, hydroxyethylidene diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, hexamethylenediaminetetramethylenephosphonic acid, ethylenediamine-N,N'-disuccinic acid, glutamic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, ethylene glycol tetraacetic acid, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N''-tetraacetic acid, ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid), propylenediaminetetraacetic acid.

11. The composition for removing residues after etching according to claim 1, characterized in that, The mass percentage content range of the organic solvent is 30wt% - 60wt%; the mass percentage content range of the fluoride is 0.1wt% - 5wt%; the mass percentage content range of the corrosion inhibitor is 1wt% - 25wt%; the mass percentage content range of water is 20wt% - 50wt%.

12. The composition for removing residues after etching according to claim 11, characterized in that, The mass percentage content range of the organic solvent is 35% - 55%; the mass percentage content range of the fluoride is 0.5wt% - 3wt%; the mass percentage content range of the corrosion inhibitor is 5wt% - 20wt%; the mass percentage content range of water is 30wt% - 45wt%.

13. The composition for removing residues after etching according to claim 8, characterized in that, The mass percentage content range of the pH regulator is 0.1wt% - 10wt%.

14. The composition for removing residues after etching according to claim 13, characterized in that, The mass percentage content range of the pH regulator is 1 wt% - 5 wt%.

15. The composition for removing post-etch residues according to claim 10, wherein, The mass percentage content range of the chelating agent is 0.01 wt% - 5 wt%.

16. The composition for removing post-etch residues according to claim 15, wherein, The mass percentage content range of the chelating agent is 0.1 wt% - 3 wt%.

17. The composition for removing post-etch residues according to claim 1, wherein, The pH value is 6 - 9.

18. The composition for removing post-etch residues according to claim 17, wherein, The pH value is 6.5 - 8.

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