Polishing composition for semiconductor process and method for polishing substrate using same

Abstract

A polishing composition for a semiconductor process according to one embodiment of the present specification includes polishing particles and a nonionic surfactant. A contact angle of the polishing composition for a semiconductor process with a silicon oxide film is 30-40 DEG. When the polishing composition for a semiconductor process is applied to a chemical mechanical polishing (CMP) process, a polished surface with improved flatness and reduced frequency of occurrence of defects can be provided, and convenience of the polishing process can be improved.

Description

TECHNICAL FIELD

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to Korean Patent Application No. 10-2023-0087769, filed on July 6, 2023, the contents of which are incorporated herein by reference in its entirety.

[0002] Embodiments relate to a polishing composition for semiconductor processes and a polishing method of a substrate using the same, etc. BACKGROUND

[0003] As semiconductor devices are more fine and high-density, a more fine pattern forming technique is used, and thus the surface structure of the semiconductor device becomes more complex, and the height difference of the interlayer film becomes greater. In the process of manufacturing the semiconductor device, a chemical mechanical polishing (hereinafter, referred to as "CMP") process is used as a planarization technique for removing the height difference on a specific film formed on a substrate.

[0004] For the CMP process, a slurry is provided to a polishing pad, and the substrate is pressed and rotated, and thus the surface is polished. Depending on the process step, the object to be planarized becomes different, and the physical properties of the slurry to be used also differ.

[0005] Polishing after forming a metal wiring needs to minimize dishing or erosion, etc., while maintaining sufficient polishing rate and polishing speed.

[0006] PRIOR ART DOCUMENT PATENT DOCUMENT (Patent Document 1) Korean Patent Publication No. 10-2017-0021320 (Patent Document 2) Japanese Patent Publication No. H11-060232 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION Embodiments aim to provide a polishing composition for semiconductor processes, which can achieve a polished surface with improved flatness and reduced defect occurrence frequency when applied to a CMP process, and improve the convenience of the polishing process.

[0007] MEANS FOR SOLVING THE PROBLEMS A polishing composition for semiconductor processes according to an embodiment of the present specification includes a polishing particle and a nonionic surfactant.

[0008] The polishing composition for semiconductor processes described above has a contact angle of 30° to 40° with respect to a silicon oxide film.

[0009] The dynamic surface tension of the polishing composition for semiconductor processing described above can be 70 mN / m or less at a bubble lifetime of 10 seconds.

[0010] The viscosity of the polishing composition for semiconductor processing described above can be 0.7 cP to 1.5 cP at 25°C.

[0011] The pH of the polishing composition for semiconductor processing described above can be 3.5 to 5.

[0012] The ζ potential of the polishing composition for semiconductor processing described above can be +10 mV to +50 mV.

[0013] The polishing composition for semiconductor processing described above can further include an antifoaming agent.

[0014] The antifoaming agent described above can include a water-soluble polymer.

[0015] The antifoaming agent described above can include a polyglycerol compound.

[0016] The weight average molecular weight of the antifoaming agent described above can be 200 g / mol to 2000 g / mol.

[0017] The nonionic surfactant described above can include a polymeric surfactant.

[0018] The weight average molecular weight of the polymeric surfactant described above can be 150 g / mol to 3000 g / mol.

[0019] The surface of the polishing particle described above can be positively charged.

[0020] The method of manufacturing a substrate according to another embodiment of the present specification includes a process of polishing a substrate by applying the polishing composition for semiconductor processing described above as a slurry.

[0021] Effects of the Invention The polishing composition for semiconductor processing of the embodiments can achieve a polished surface having improved flatness and reduced defect occurrence frequency when applied to a CMP process, and improve the convenience of the polishing process. DETAILED DESCRIPTION

[0022] Hereinafter, the embodiments will be described in detail so that a person of ordinary skill in the art to which the embodiments pertain can easily practice. However, the embodiments can be implemented in various different forms and are not limited to the embodiments described herein.

[0023] The terms "about", "substantially" and the like used in the present specification are used in the meaning that the inherent manufacturing and material tolerances are proposed in the meaning of the values mentioned or close thereto, for the purpose of preventing unscrupulous persons from improperly using the disclosure of accurate or absolute values for the purpose of facilitating understanding of the embodiments.

[0024] Throughout the present specification, the term "combinations thereof" included in the expression of Markush form means a mixture or combination of one or more selected from the group consisting of the plurality of structural elements recited in the expression of Markush form, and means to include one or more selected from the group consisting of the above structural elements.

[0025] Throughout the present specification, the recitation of "A and / or B" means "A, B, or A and B".

[0026] Throughout the present specification, unless otherwise specified, terms such as "first", "second", or "A", "B", etc. are used to distinguish the same terms.

[0027] In the present specification, B being on A means that B is on A, or B can be on A in a manner that other layers are interposed therebetween, and should not be limited to be interpreted as B being on A in a manner that B is in contact with the surface of A.

[0028] In the present specification, unless otherwise specified, a singular expression is interpreted to include the meaning of a singular or plural as interpreted in the context.

[0029] Hereinafter, implementation examples will be specifically described.

[0030] Physical properties of polishing composition The polishing composition for semiconductor process according to the implementation examples includes polishing particles and a nonionic surfactant.

[0031] The polishing composition for semiconductor process has a contact angle with respect to a silicon oxide film of 30° to 40°.

[0032] The polishing composition having a controlled contact angle with respect to a silicon oxide film has improved affinity with respect to a substrate surface including a silicon oxide film, and can be uniformly distributed over the entire substrate surface during polishing. Thereby, the substrate surface can be polished to have a more smooth surface. In addition, the affinity of the polishing composition with respect to various particles such as polishing particles, organic matters, etc. is improved, and thereby the number of particles adsorbed on the substrate surface can be effectively reduced.

[0033] The contact angle of the polishing composition with respect to a silicon oxide film is measured by a contact angle meter. Specifically, according to a sessile drop method, 0.4 mL of the polishing composition is dropped on a silicon oxide film wafer, and then the contact angle of the polishing composition is measured by a contact angle meter. Exemplarily, the contact angle meter can be applicable to a model of Phoenix-MT of SEO company.

[0034] The contact angle of the polishing composition with respect to a silicon oxide film can be 30° to 40°. The contact angle can be 38° or less. The contact angle can be 32° or more. When a polishing composition having such characteristics is used in a CMP process, a more precisely polished substrate surface can be provided. In addition, the frequency of defects caused by particles adsorbed to the polished surface can be effectively reduced.

[0035] The dynamic surface tension of the polishing composition for semiconductor processing can be 70 mN / m or less at a bubble lifetime of 10 seconds.

[0036] The polishing composition of the embodiment can exhibit a relatively low dynamic surface tension, i.e., a low surface energy, at a short bubble lifetime. Such a polishing composition can exhibit stable affinity with respect to a substrate surface and organic particles even when frequent movement occurs between the substrate and the polishing pad due to relative movement. In addition, in the embodiment, the dynamic surface tension of the polishing composition is adjusted to a predetermined range, which helps to improve the dispersibility of the polishing particles.

[0037] The dynamic surface tension of the polishing composition is measured using a bubble pressure tensiometer by a maximum bubble pressure method. The maximum bubble pressure method is a method in which a polishing composition to be measured is inserted into a capillary, the internal pressure of a bubble formed at the end of the capillary is measured when a gas is injected into the capillary, and the dynamic surface tension is calculated from the measured value. In the maximum bubble pressure method, the bubble lifetime refers to the time required for the internal pressure of the bubble to reach a maximum from the time when the bubble is formed at the end of the capillary.

[0038] When the dynamic surface tension is measured, the time interval is set to 1 second, and the sample volume is set to 2 mL. As an example, the bubble pressure tensiometer can be a model BPA-1P of Sinterface Tech Co.

[0039] The dynamic surface tension of the polishing composition for semiconductor processing can be 70 mN / m or less at a bubble lifetime of 10 seconds. The dynamic surface tension can be 69 mN / m or less. The dynamic surface tension can be 30 mN / m or more. When a polishing composition having such characteristics is used in a CMP process, a polished surface in which the frequency of defects is effectively reduced can be provided.

[0040] The viscosity of the polishing composition for semiconductor processing can be 0.7 cP to 1.5 cP at 25°C.

[0041] In the CMP process, the polishing pad and the substrate are moved in rotation under pressure, and strong external force can act on the polishing composition supplied to the substrate. For a polishing composition containing a surfactant, if the above polishing process is continuously performed, excessive foam can be generated. The embodiments achieve to reduce the degree of foam generation during polishing to a certain level or below or to help the generated foam to disappear quickly by adjusting the viscosity of the polishing composition. In addition, controlling the viscosity of the polishing composition helps to make the polishing rate of the polishing composition to the polished surface stable for a long time.

[0042] The viscosity of the polishing composition is measured by a viscometer.

[0043] The viscosity of the polishing composition for semiconductor process can be 0.7 cP to 1.5 cP at 25°C. The viscosity can be 0.8 cP or more. The viscosity can be 0.9 cP or more. The viscosity can be 1.3 cP or less. The viscosity can be 1.1 cP or less. If the viscosity of the polishing composition is controlled within the above range, it is possible to prevent excessive foam from being generated during polishing while helping the polishing composition to maintain a stable polishing rate to the polished surface.

[0044] The pH of the polishing composition for semiconductor process can be 3.5 to 5. The pH can be 3.8 or more. The pH can be 4.0 or more. The pH can be 4.8 or less. The pH can be 4.6 or less. The pH can be 4.4 or less. The pH can be 4.3 or less. In this case, the polishing composition can exhibit excellent polishing properties to the polished surface such as a silicon oxide film and help the polishing particles to be stably dispersed.

[0045] The pH of the polishing composition for semiconductor process is measured by a pH meter.

[0046] The ζ potential of the polishing composition for semiconductor process can be +10 mV to +50 mV. The ζ potential can be +15 mV or more. The ζ potential can be +20 mV or more. The ζ potential can be +45 mV or less.

[0047] The ζ potential of the polishing particles can be +10 mV to +50 mV. The ζ potential can be +15 mV or more. The ζ potential can be +20 mV or more. The ζ potential can be +45 mV or less.

[0048] In this case, the polishing composition can exhibit stable dispersibility while exhibiting excellent polishing properties to a silicon oxide film having a surface negative charge.

[0049] Composition of polishing composition Polishing particles The polishing composition can include a polishing particle.

[0050] The polishing particle can include a metal oxide particle and / or a silicon oxide particle. The polishing particle can include silica. The polishing particle can include colloidal silica.

[0051] The polishing particle can include 70% by weight or more of colloidal silica. The polishing particle can include 80% by weight or more of colloidal silica. The polishing particle can include 90% by weight or more of colloidal silica. The polishing particle can be colloidal silica.

[0052] The surface of the polishing particle can be positively charged. The polishing particle can be surface-modified to have a positively charged surface. The polishing particle can be surface-modified with a compound having an amine group. The polishing particle can be surface-modified with an amino silane.

[0053] Exemplarily, the above-mentioned amino silane can be one selected from the group consisting of 3-aminopropyltriethoxysilane, bis[(3-triethoxysilyl)propyl]amine, 3-aminopropyltrimethoxysilane, bis[3-(trimethoxysilyl)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine, N-bis[3-(trimethoxysilyl)propyl]-1,2-ethanediamine, N-[3-(triethoxysilyl)propyl]ethylenediamine, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylaminomethyltriethoxysilane, diethylaminopropyltrimethoxysilane, diethylaminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]butylamine, and combinations thereof.

[0054] The polishing composition for semiconductor process can contain 50 ppm (weight basis) to 300 ppm (weight basis) of the amino silane. The polishing composition for semiconductor process can contain 70 ppm (weight basis) or more of the amino silane. The polishing composition for semiconductor process can contain 100 ppm (weight basis) or more of the amino silane. The polishing composition for semiconductor process can contain 120 ppm (weight basis) or more of the amino silane. The polishing composition for semiconductor process can contain 250 ppm (weight basis) or less of the amino silane. The polishing composition for semiconductor process can contain 220 ppm (weight basis) or less of the amino silane. The polishing composition for semiconductor process can contain 200 ppm (weight basis) or less of the amino silane. The polishing composition for semiconductor process can contain 180 ppm (weight basis) or less of the amino silane. In this case, the polishing composition has more excellent polishing rate for a silicon oxide film, can more smoothly polish the surface of the polishing target substrate, and can exhibit improved dispersibility. Meanwhile, the occurrence of the residue of the surface modifier can be effectively suppressed, and thus the above-mentioned residue can be adsorbed to the polished surface.

[0055] The polishing composition for semiconductor process can contain 1 wt% to 10 wt% of the polishing particles. The polishing composition for semiconductor process can contain 2 wt% or more of the polishing particles. The polishing composition for semiconductor process can contain 8 wt% or less of the polishing particles. The polishing composition for semiconductor process can contain 5 wt% or less of the polishing particles. In this case, the polishing composition can have excellent polishing rate for the polished surface while stably suppressing the aggregation of the polishing particles.

[0056] The average particle diameter of the above-mentioned polishing particles can be 20 nm or more. The above-mentioned particle diameter can be 30 nm or more. The above-mentioned particle diameter can be 40 nm or more. The above-mentioned particle diameter can be 70 nm or less. The above-mentioned particle diameter can be 60 nm or less. The above-mentioned particle diameter can be 50 nm or less. In this case, the polishing composition can exhibit excellent polishing rate for the polished surface while stably adjusting the frequency of defects occurring on the polished surface.

[0057] The above-mentioned average particle diameter means the average particle diameter of the primary particles of the above-mentioned polishing particles.

[0058] Surfactants The polishing composition for semiconductor process contains the nonionic surfactant. The nonionic surfactant can improve the affinity of the polishing composition for a silicon oxide film, and can uniformly distribute the polishing composition on the polished surface during the polishing process. In addition, the nonionic surfactant is attached to the polished surface with appropriate strength, and can effectively hinder the adsorption of the polishing particles having a surface positive charge to the surface of the polished surface, and also easily remove the polishing particles from the surface of the polished substrate.

[0059] The nonionic surfactant can include a high-molecular surfactant. The weight average molecular weight of the high-molecular surfactant can be 150 g / mol to 3000 g / mol.

[0060] The implementation example can apply a nonionic surfactant having a main chain length adjusted, i.e., a high-molecular surfactant, to a polishing composition. Thereby, it is possible to effectively prevent the nonionic surfactant adsorbed on a polished surface from causing a decrease in the polishing rate of the polishing composition on the polished surface.

[0061] The weight average molecular weight of the high-molecular surfactant is measured by gel permeation chromatography (GPC).

[0062] The nonionic surfactant can include 70% by weight or more of the high-molecular surfactant. The nonionic surfactant can include 80% by weight or more of the high-molecular surfactant. The nonionic surfactant can include 90% by weight or more of the high-molecular surfactant. The nonionic surfactant can include 100% by weight or less of the high-molecular surfactant. The nonionic surfactant can be the high-molecular surfactant.

[0063] The weight average molecular weight of the high-molecular surfactant can be 150 g / mol to 3000 g / mol. The weight average molecular weight can be 300 g / mol or more. The weight average molecular weight can be 500 g / mol or more. The weight average molecular weight can be 2500 g / mol or less. The weight average molecular weight can be 2000 g / mol or less. The weight average molecular weight can be 1500 g / mol or less. In this case, it is possible to effectively improve the wettability of the polishing composition on a silicon oxide film while stably adjusting the polishing rate of the polishing composition on the silicon oxide film, and to effectively suppress the occurrence of defects caused by polishing particles in the polished surface.

[0064] The nonionic surfactant can be a fluorine-based surfactant. The nonionic surfactant can be a fluoroalkyl alkylene oxide compound. The nonionic surfactant can be a compound of the following Chemical Formula 1.

[0065] [Chemical Formula 1] R f -(R en -O) n -H In the above Chemical Formula 1, the R f is a fluoroalkyl group having 3 to 10 carbon atoms, the R en is an alkylene group having 2 or 3 carbon atoms, and n is an integer of 2 to 15.

[0066] In the above Chemical Formula 1, R f The perfluoroalkyl group can have 3 to 10 carbon atoms.

[0067] Exemplarily, the nonionic surfactant is triethylene glycol perfluoropentyl ether, triethylene glycol perfluorohexyl ether, triethylene glycol perfluoroheptyl ether, tetraethylene glycol perfluoropentyl ether, tetraethylene glycol perfluorohexyl ether, tetraethylene glycol perfluoroheptyl ether, pentaethylene glycol perfluoropentyl ether, pentaethylene glycol perfluorohexyl ether, pentaethylene glycol perfluoroheptyl ether, hexaethylene glycol perfluoropentyl ether, hexaethylene glycol perfluorohexyl ether, hexaethylene glycol perfluoroheptyl ether, etc.

[0068] The polishing composition for semiconductor process can contain 10 ppm or more of the nonionic surfactant. The polishing composition for semiconductor process can contain 20 ppm or more of the nonionic surfactant. The polishing composition for semiconductor process can contain 50 ppm or more of the nonionic surfactant. The polishing composition for semiconductor process can contain 100 ppm or more of the nonionic surfactant. The polishing composition for semiconductor process can contain 150 ppm or more of the nonionic surfactant. The polishing composition for semiconductor process can contain 500 ppm or less of the nonionic surfactant. The polishing composition for semiconductor process can contain 450 ppm or less of the nonionic surfactant. In this case, the affinity of the polishing composition to the polished surface can be effectively improved, while the excessive generation of bubbles during polishing is suppressed.

[0069] Defoamers The polishing composition for semiconductor process further contains an antifoaming agent. The antifoaming agent is a substance different from the above nonionic surfactant.

[0070] The implementation example can provide a polishing composition having improved wettability to a silicon oxide film, while effectively suppressing the generation of bubbles during polishing, by simultaneously applying the nonionic surfactant and the antifoaming agent to the polishing composition. In addition, the antifoaming agent can help improve the affinity of the polishing composition to the silicon oxide film.

[0071] The antifoaming agent can contain a water-soluble polymer. The water-soluble polymer can be uniformly distributed in the polishing composition without excessively increasing the viscosity of the above composition, thereby effectively suppressing the generation of bubbles in the polishing composition.

[0072] The antifoaming agent can contain a polyglycerol compound.

[0073] The polyglycerol compound refers to polyglycerol and derivatives thereof. Exemplarily, the polyglycerol compound is polyglyceryl-3, polyglyceryl-4, polyglyceryl-5, polyglyceryl-10, polyglyceryl-20, etc.

[0074] The weight average molecular weight of the defoaming agent can be 200 g / mol to 2000 g / mol. The weight average molecular weight can be 500 g / mol or more. The weight average molecular weight can be 1500 g / mol or less. The weight average molecular weight can be 1200 g / mol or less. In this case, the viscosity of the polishing composition can be inhibited from increasing excessively, and the formation of bubbles that can occur during polishing can be effectively inhibited.

[0075] The weight average molecular weight of the defoaming agent is measured by gel permeation chromatography (GPC).

[0076] The polishing composition for semiconductor processes can contain 0.001% by weight or more of the defoaming agent. The polishing composition for semiconductor processes can contain 0.003% by weight or more of the defoaming agent. The polishing composition for semiconductor processes can contain 0.005% by weight or more of the defoaming agent. The polishing composition for semiconductor processes can contain 0.1% by weight or less of the defoaming agent. The polishing composition for semiconductor processes can contain 0.08% by weight or less of the defoaming agent. The polishing composition for semiconductor processes can contain 0.05% by weight or less of the defoaming agent. The polishing composition for semiconductor processes can contain 0.03% by weight or less of the defoaming agent. In this case, the formation of bubbles in the polishing composition during polishing can be inhibited, and the convenience of the polishing process can be effectively improved.

[0077] Other additives The polishing composition for semiconductor processes can further contain other additives. As the additives, any additive generally used in the CMP field is acceptable. Illustratively, the additives can be at least one of chelating agents, oxidizing agents, acid components, pH adjustors, dispersants, polishing rate improvers, polishing modifiers, polishing pad protectors, and preservatives.

[0078] The polishing composition for semiconductor processes can further contain a chelating agent. Metals or metal ions removed from the surface of a substrate during polishing can re-attach or remain on the surface of the substrate, forming defects. In particular, metals such as tungsten can have a property of easily dissolving in a polishing composition but easily attaching to the surface of a polishing object under certain conditions. The chelating agent can adsorb to such metals or metal ions, thereby easily removing the metals and the like. As a result, the polishing rate of the polishing composition can be further improved, and defects formed on the surface of the substrate due to the re-attachment of particles can be effectively inhibited.

[0079] Exemplarily, the chelating agent can be at least one selected from the group consisting of butyric acid, citric acid, tartaric acid, succinic acid, oxalic acid, acetic acid, adipic acid, capric acid, caproic acid, caprylic acid, carboxylic acid, glutaric acid, glutamic acid, glycolic acid, mercaptoacetic acid, formic acid, mandelic acid, fumaric acid, lactic acid, lauric acid, malic acid, maleic acid, malonic acid, myristic acid, palmitic acid, phthalic acid, isophthalic acid, terephthalic acid, citraconic acid, propionic acid, pyruvic acid, stearic acid, valeric acid, benzoic acid, phenylacetic acid, naphthoic acid, aspartic acid, amino acid, and ethylenediaminetetraacetic acid.

[0080] As the amino acid, glycine, α-alanine, β-alanine, L-aspartic acid, N-methyl glycine (sarcosine), and combinations thereof can be used.

[0081] The chelating agent can include two or more carboxyl groups or alcohol groups in a molecule. As the chelating agent, two or more of the cases in which two or more carboxyl groups or alcohol groups are included in a molecule can be used. Specifically, the chelating agent can include one selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), glycine, carboxylic acid, and combinations thereof. The carboxylic acid refers to a compound including at least one or two or more carboxyl groups in a molecule.

[0082] The polishing composition for semiconductor processes can include 0.003 wt% to 0.5 wt% of the chelating agent. The polishing composition for semiconductor processes can include 0.005 wt% or more of the chelating agent. The polishing composition for semiconductor processes can include 0.3 wt% or less of the chelating agent. In this case, the polishing rate of the polishing composition can be controlled at an appropriate level, and the frequency of occurrence of surface defects of the substrate can be reduced.

[0083] The polishing composition for semiconductor processes can further include an oxidizing agent. The oxidizing agent can oxidize metals such as tungsten, create an environment in which the surface of the substrate can be more easily planarized, and function to increase the polishing rate and the etching rate.

[0084] The oxidizing agent can be at least one selected from the group consisting of hydrogen peroxide, urea hydrogen peroxide, urea, percarbonate, periodate, periodate salt, perchlorate, perchlorate salt, perbromate, perbromate salt, perborate, perborate salt, permanganate, permanganate salt, persulfate, bromate, chlorate, chlorite, chromate, iodate, iodous acid, ammonium persulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide, and urea peroxide.

[0085] The polishing composition for semiconductor processes can include 0.01 wt% to 5 wt% of the oxidizing agent. In this case, the composition can exhibit excellent polishing properties with respect to metals, and the formation of an oxide film on the polishing target metal during polishing can be inhibited.

[0086] The polishing composition for semiconductor processes can further include a copper corrosion inhibitor. The copper corrosion inhibitor can include an azole compound.

[0087] Exemplarily, the azole compound can include one selected from the group consisting of Benzotriazole (BTA), 5-Methyl-lH-Benzotriazole (5-MBTA), 3-Amino-l,2,4-Triazole, 5-Phenyl-lH-Tetrazole, 3-Amino-5-Methyl-4H-l,2,4-Triazole, 5-Aminotetrazole (ATZ), 1,2,4-Triazole, Tolyltriazole, and combinations thereof.

[0088] The azole compound can include one selected from the group consisting of 5-Aminotetrazole (ATZ), 5-Methyl-lH-Benzotriazole (5-MBTA), and combinations thereof.

[0089] The azole compound can act on the surface of copper during the polishing process to prevent corrosion of copper.

[0090] The azole compound can be included in an amount of 0.02 to 2.00 parts by weight, 0.03 to 1.5 parts by weight, or 0.5 to 1.5 parts by weight, based on 100 parts by weight of the polishing particles.

[0091] When the azole compound is included in such a range, the corrosion prevention effect of the composition for semiconductor processes on the surface of copper can be obtained, and in particular, the corrosion prevention effect can be provided more strongly than on a relatively wide surface such as a via surface.

[0092] The polishing composition for semiconductor processes can further include an acid component. Exemplarily, the acid component can be at least one selected from the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, fluoric acid, bromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, adipic acid, acetic acid, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid, and salts thereof.

[0093] The polishing composition for semiconductor processes can further include a pH adjuster together with the acid component. Illustratively, the pH adjuster can be any one selected from the group consisting of ammonia, aminomethyl propanol, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate, imidazole, and combinations thereof.

[0094] The polishing composition for semiconductor processes can further include a dispersant.

[0095] The dispersant can prevent agglomeration between the polishing particles in the polishing composition, allowing uniform dispersion. A cationic dispersant can increase the zeta potential of the polishing composition to a positive value, and an anionic dispersant can decrease the zeta potential of the polishing composition to a negative value.

[0096] The dispersant can include an anionic low molecule, a cationic high molecule, an organic acid, etc.

[0097] The anionic low molecule of the dispersant can be one or more selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, and combinations thereof.

[0098] The cationic high molecule of the dispersant can be one or more selected from polylysine, polyethyleneimine, benzalkonium chloride, 5-bromo-5-nitro-1,3-dioxane (bronidox), cetyltrimethylammonium bromide, cetyltrimethylammonium chloride, dimethyloctadecylammonium chloride, tetramethylammonium hydroxide, distearyldimethylammonium chloride, polyallylamine, and combinations thereof.

[0099] The organic acid of the dispersant can be one or more selected from hydroxybenzoic acid, ascorbic acid, picolinic acid, glutamic acid, tryptophan, aminobutyric acid, and combinations thereof.

[0100] The polishing rate enhancer is an additive for increasing the polishing rate of a polishing target substrate or wiring, and can be one or more selected from potassium nitrate, iron nitrate, ammonium hydroxide, citric acid, acetic acid, and combinations thereof.

[0101] The polishing adjuster is used to minimize the adsorption of the polishing composition to a metal surface, and can include an ammonium compound, potassium nitrate, an amino acid, a salt thereof, etc.

[0102] The polishing composition for semiconductor processes can include a solvent. The above-described solvent can be water, and specifically, can be ultrapure water.

[0103] Polishing properties of polishing composition The polishing rate of the polishing composition for semiconductor processes on a silicon oxide film can be 1000 A / min or more. The polishing rate can be 1100 A / min or more. The polishing rate can be 1200 A / min or more. The polishing rate can be 3000 A / min or less. The polishing rate can be 2500 A / min or less. The polishing rate can be 2000 A / min or less.

[0104] The polishing rate of the polishing composition for semiconductor processes on a tungsten film can be 50 A / min or more. The polishing rate can be 70 A / min or more. The polishing rate can be 500 A / min or less. The polishing rate can be 300 A / min or less. The polishing rate can be 200 A / min or less.

[0105] In this case, the polishing composition can exhibit a superior polishing rate selectivity for a silicon oxide film over a tungsten film.

[0106] The Ra value of a tungsten film measured after polishing for 30 seconds using the polishing composition for semiconductor processes can be 3 nm or less. The Ra value can be 2 nm or less. In this case, the polishing composition can provide a polished surface having a smoother surface.

[0107] The Ra value is measured according to ISO 4287.

[0108] The polishing is performed on each film under the conditions of a pressure of 2.2 psi, a carrier rotation speed of 87 rpm, a platen rotation speed of 93 rpm, and a slurry flow rate of 250 ml / min. The polishing pad can be a model SR-300 of SK Enpulse Co.

[0109] When the polishing rate is measured on each film, the polisher can exemplarily be a model AP-300 of CTS Co.

[0110] Method for manufacturing a substrate The manufacturing method of the substrate of the embodiment includes a process of polishing the substrate using the polishing composition for semiconductor processes as a slurry.

[0111] The substrate can include at least one of an insulating film, a metal wiring, and a barrier layer on the upper surface. The metal wiring can include copper or tungsten. When the metal wiring includes copper, the barrier layer can include tantalum and a nitride thereof. When the metal wiring includes tungsten, the barrier layer can include titanium and a nitride thereof.

[0112] Specifically, the process of polishing the substrate includes bringing the substrate as a polishing target in contact with the polishing composition for semiconductor processes supplied from a nozzle onto a polishing pad, rotating a polishing head that fixes the substrate, and rotating a turntable to which the polishing pad is attached.

[0113] The process of polishing the substrate can further include a step of adjusting the surface of the polishing pad before polishing, as necessary.

[0114] The polishing composition for semiconductor processes can polish the wafer in contact with the polishing pad while permeating toward the substrate.

[0115] In the process of polishing the substrate, a pressure of 6.89 kPa to 48.26 kPa can be applied. The pressure can be 13.79 kPa to 34.47 kPa.

[0116] The process of polishing the substrate can be performed for 50 seconds to 10 minutes. However, it can be changed according to the target polishing degree.

[0117] The description of the polishing composition for semiconductor processes is repeated as the foregoing, and thus is omitted.

[0118] The method of manufacturing the substrate can further include a cleaning process of cleaning the substrate on which polishing is completed.

[0119] The cleaning process can be performed in a manner of cleaning the substrate on which polishing is completed with purified water and a non-reactive gas.

[0120] Hereinafter, specific examples are described in more detail. The following examples are merely illustrative for helping understanding of the present application, and the scope of the present application is not limited thereto.

[0121] Manufacturing Example: Manufacturing of Polishing Composition Example 1: A polishing composition of 100% by weight was prepared by mixing 2% by weight of silica having an average diameter (primary particle basis) of 45 nm, which is surface-modified with (3-aminopropyl)triethoxysilane of 150 ppm (weight basis), as a polishing particle, 100 ppm (weight basis) of FS 3100 of Capstone Inc. of the U.S., which is a non-ionic surfactant, as a non-ionic surfactant, and nitric acid as a pH adjuster, in ultrapure water as a solvent. The pH of the polishing composition was adjusted to 3.8.

[0122] Example 2: A polishing composition of 100% by weight was prepared under the same conditions as in Example 1, by applying the same components, except that 0.01% by weight (excluding the amount of ultrapure water) of polyglycerol having a weight average molecular weight of 750 g / mol was further included.

[0123] Example 3: A polishing composition of 100% by weight was prepared under the same conditions as in Example 1, by applying 30 ppm of a non-ionic surfactant, except that.

[0124] Comparative Example 1: A polishing composition of 100% by weight was prepared under the same conditions as in Example 1 except that no nonionic surfactant was applied.

[0125] Comparative Example 2: A polishing composition of 100% by weight was prepared under the same conditions as in Example 1 except that 1000 ppm of nonionic surfactant was applied.

[0126] Comparative Example 3: A polishing composition of 100% by weight was prepared by mixing 2% by weight of silica having an average diameter (primary particle basis) of 45 nm, which was not surface-modified, as a polishing particle, in ultrapure water as a solvent, nitric acid as a pH adjuster, and preparing a polishing composition of 100% by weight. The pH of the polishing composition was adjusted to 3.8.

[0127] The amounts of the respective components in the polishing compositions of the respective examples and comparative examples, the zeta potential of the polishing compositions, and the viscosity were applied as described in Table 1 below.

[0128] Evaluation Example: Measurement of contact angle of polishing composition with respect to silicon oxide film The contact angles of the polishing compositions of the respective examples and comparative examples with respect to the silicon oxide film were measured using a contact angle meter Phoenix-MT manufactured by SEO Corporation. Specifically, 0.4 mL of the polishing composition of the respective examples and comparative examples was dropped on a silicon oxide film wafer according to the sessile drop method, and the contact angle of the polishing composition was measured using the contact angle meter.

[0129] The measured values of the respective examples and comparative examples are described in Table 2 below.

[0130] Evaluation Example: Measurement of dynamic surface tension of polishing composition The dynamic surface tension of the polishing compositions of Example 3 and Comparative Example 1 was measured using a bubble pressure apparatus BPA-1P manufactured by Sinterface Tech Corporation and by the maximum bubble pressure method. When the dynamic surface tension was measured, the time interval was set to 1 second, and the sample volume was set to 2 mL. The measured dynamic surface tension was measured as the value at a bubble lifetime of 10 seconds.

[0131] The measured values of the respective examples and comparative examples are described in Table 2 below.

[0132] Evaluation Example: Measurement of polishing rate with respect to each film Each of the polishing compositions of Examples 1 to 3 and Comparative Examples 1 and 2 was applied as a slurry, and the polishing rates on a silicon oxide film and a tungsten film formed on a wafer having a diameter of 300 mm were measured. The polishing rates on each of the films were measured under the conditions of a polishing time of 60 seconds, a pressure of 2.2 psi, a carrier head speed of 93 rpm, a polishing disk rotation speed of 87 rpm, and a slurry flow rate of 300 ml / min, using a polishing machine of Model AP-300 manufactured by CTS Corporation.

[0133] The measured values of the polishing rates on each of the films of the different examples and comparative examples are shown in Table 3 below.

[0134] Evaluation Example: Measurement of Polished Surface Roughness The polishing compositions of Example 1 and Comparative Example 3 were applied as a slurry, and a tungsten film formed on a wafer having a diameter of 300 mm and an arithmetic average roughness (Ra) value of 10.33 nm according to ISO 4287 was polished. The tungsten film was polished under the same conditions as those applied in the aforementioned polishing rate measurement evaluation example, and the polishing time was 30 seconds.

[0135] Subsequently, the arithmetic average roughness (Ra) according to ISO 4287 of the surface of the tungsten film polished to completion by the polishing composition of the different examples and comparative examples was measured using a Park XE-100 manufactured by Park systems as an atomic force microscope.

[0136] The measured values of the different examples and comparative examples are shown in Table 3 below.

[0137] Evaluation Example: Measurement of Defect Density of Polished Surface The polishing compositions of Example 1, Example 3, Comparative Example 1, and Comparative Example 2 were applied as a slurry, and a silicon oxide film formed on a wafer having a diameter of 300 mm was polished. The silicon oxide film was polished under the same conditions as those applied in the aforementioned polishing rate measurement evaluation example.

[0138] The number of defects formed on the surface of the SiO2 wafer polished to completion was measured using an AIT-XP+ manufactured by KLA Tencor as a wafer defect detector.

[0139] The measured results of the different examples and comparative examples are shown in Table 3 below.

[0140] Evaluation Example: Measurement of Degree of Foam Generation The polishing compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were put into a circular cylinder having a diameter of 150 mm, and then a propeller having a blade diameter of 100 mm was disposed in the polishing composition. The rotation speed of the propeller was set to 100 RPM, and the composition was stirred for 1 minute. The height of the foam generated in the polishing composition at the end of the stirring was measured.

[0141] The results of the measurements of the different examples and comparative examples are shown in Table 3 below.

[0142] [Table 1]

[0143] [Table 2]

[0144] [Table 3]

[0145] As for the Ra value of the polished surface of Table 3, Example 1 measured 2 nm or less, while Comparative Example 3 measured more than 4.5 nm. This means that the polishing particles that have been surface-modified can achieve a smoother polished surface. As for the defect density of the polished surface, in Example 1, Example 3, and Comparative Example 2, the defects per wafer were measured to be 100 or less, while in Comparative Example 1, the defects per wafer were measured to be more than 850. This is because the polishing composition whose contact angle with the silicon oxide film is controlled can be uniformly distributed in the polished surface during polishing, and the surfactant hinders the adsorption of the polishing particles in the polished surface.

[0146] As for the height of the foam, Example 2 generated less foam than Example 1. This is because the polyglycerol contained in the polishing composition of Example 2 effectively suppressed the generation of foam during stirring.

[0147] The above describes preferred embodiments, but the scope of the rights of the present invention is not limited thereto, and various modifications and improvements of the basic concept of the embodiments defined in the appended claims by those skilled in the art to which the present invention pertains also belong to the scope of the present invention.

Claims

1. A polishing composition for semiconductor processes, characterized in that, It contains polishing particles and nonionic surfactants; The contact angle for the silicon oxide film is 30° to 40°.

2. The polishing composition for semiconductor processing according to claim 1, characterized in that, The dynamic surface tension is below 70 mN / m when the bubble lifetime is 10 seconds.

3. The polishing composition for semiconductor processing according to claim 1, characterized in that, The viscosity at 25°C is 0.7 cP to 1.5 cP.

4. The polishing composition for semiconductor processing according to claim 1, characterized in that, The pH ranges from 3.5 to 5.

5. The polishing composition for semiconductor processing according to claim 1, characterized in that, The zeta potential ranges from +10mV to +50mV.

6. The polishing composition for semiconductor processes according to claim 1, characterized in that, It also contains defoamer. The aforementioned defoamer contains water-soluble polymers.

7. The polishing composition for semiconductor processing according to claim 6, characterized in that, The aforementioned defoamers include polyglycerol compounds.

8. The polishing composition for semiconductor processes according to claim 6, characterized in that, The weight-average molecular weight of the above-mentioned defoamers ranges from 200 g / mol to 2000 g / mol.

9. The polishing composition for semiconductor processing according to claim 1, characterized in that, The aforementioned nonionic surfactants include polymeric surfactants. The weight-average molecular weight of the aforementioned high-molecular surfactants ranges from 150 g / mol to 3000 g / mol.

10. The polishing composition for semiconductor processing according to claim 1, characterized in that, The surface of the polished particles mentioned above carries a positive charge.

11. A method for manufacturing a substrate, characterized in that, This includes a process of polishing a substrate by applying the polishing composition for semiconductor processes according to claim 1 as a slurry.

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