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 surfactant. The volume of air bubbles measured after stirring 3 L of the polishing composition for a semiconductor step at 25 DEG C at a rate of 1000 RPM for 30 minutes and standing for 10 minutes is 50 mL or less. When the composition is applied to a chemical mechanical polishing (CMP) process, the convenience of the polishing process can be effectively improved, and a polished surface with reduced frequency of occurrence of defects can be provided.

Description

Technical Field

[0001] The embodiments relate to a polishing composition for semiconductor processes and a method for polishing a substrate using the same. Background Art

[0002] As semiconductor devices become more miniaturized and denser, more fine patterning techniques are used, resulting in more complex surface structures of semiconductor devices and larger steps in interlayer films. In the process of manufacturing semiconductor devices, a chemical mechanical polishing (hereinafter referred to as "CMP") process is used as a flattening technique for removing steps in a specific film formed on a substrate.

[0003] In the CMP process, the surface is polished by applying slurry to the polishing pad and pressing and rotating the substrate. Depending on the process steps, the object to be flattened is different, and the physical properties of the slurry used at this time are also different.

[0004] Polishing after metal wiring formation needs to maintain a sufficient polishing rate and polishing speed while minimizing dishing defects, corrosion, and the like.

[0005] Prior art literature

[0006] Patent Literature

[0007] (Patent Document 1) Korean Patent No. 10-0917955

[0008] (Patent Document 2) Korean Patent Publication No. 10-2015-0025969

[0009] (Patent Document 3) Korean Patent No. 10-1101207 Summary of the invention

[0010] Technical issues

[0011] An object of the embodiment is to provide a polishing composition for semiconductor processes which, when applied to a CMP process, can effectively improve the convenience of the polishing process and substantially reduce the frequency of defects on the polished surface.

[0012] Solutions to the problem

[0013] A polishing composition for semiconductor processes according to an embodiment of the present specification includes polishing particles and a surfactant.

[0014] 3 L of the semiconductor process polishing composition was stirred at 1000 RPM at 25° C. for 30 minutes and allowed to stand for 10 minutes. The volume of bubbles measured was 50 mL or less.

[0015] The viscosity of the polishing composition for a semiconductor process at 25° C. may be 0.7 cP to 1.5 cP.

[0016] The dynamic surface tension of the polishing composition for semiconductor processes may be 25 mN / m to 70 mN / m when the bubble life is 10 seconds.

[0017] The above-mentioned surfactant may include a nonionic surfactant.

[0018] The nonionic surfactant may include a first nonionic surfactant having a hydrophilic-lipophilic balance (HLB) value of 10 or more.

[0019] The nonionic surfactant may include a second nonionic surfactant having a hydrophilic-lipophilic balance (HLB) value of 8 or less.

[0020] The above-mentioned surfactant may include a polymer surfactant.

[0021] The weight average molecular weight of the polymer surfactant may be 150 g / mol to 3000 g / mol.

[0022] The polishing composition for semiconductor processes may further contain a defoaming agent.

[0023] The defoaming agent may contain a water-soluble polymer.

[0024] The weight average molecular weight of the defoaming agent may be 200 g / mol to 2000 g / mol.

[0025] The defoaming agent may contain a polyglycerol compound.

[0026] The pH of the semiconductor process polishing composition may be 2 to 5.

[0027] The surface of the polishing particles may have a positive charge.

[0028] A method for manufacturing a substrate according to another embodiment of the present specification includes a process of applying the above-mentioned polishing composition for a semiconductor process as a slurry to polish a substrate.

[0029] Effects of the Invention

[0030] The polishing composition for semiconductor processes of the embodiment, when applied to a CMP process, can effectively improve the convenience of the polishing process and can provide a polished surface with a reduced frequency of defects. DETAILED DESCRIPTION

[0031] The following detailed description of the embodiments can be easily implemented by those skilled in the art. However, the embodiments can be implemented in many different forms and are not limited to the embodiments described herein.

[0032] When used in this specification, the terms "about", "substantially", etc., which indicate the degree of error inherent in manufacturing and materials, are used in the sense of being from or close to their numerical values ​​to prevent unscrupulous infringers from improperly taking advantage of public content that mentions exact or absolute numerical values ​​in order to facilitate understanding of the embodiments.

[0033] Throughout this specification, the term "combination thereof" included in the Markush form expression means a mixture or combination of one or more selected from the group consisting of multiple structural elements described in the Markush form expression, and means including one or more selected from the group consisting of the above multiple structural elements.

[0034] Throughout the present specification, the description "A and / or B" means "A, B, or A and B".

[0035] Throughout the present specification, terms such as “first”, “second” or “A”, “B” and the like are used to distinguish the same terms unless otherwise specified.

[0036] In the present specification, B being located on A means that B is located on A, or other layers are located therebetween, and B may be located on A, and is not limited to being interpreted as B being located on the surface of A in a connected manner.

[0037] In the present specification, a singular expression is construed as including the singular or plural meaning as explained in the context unless otherwise specified.

[0038] Hereinafter, embodiments will be described in detail.

[0039] Physical properties of polishing composition

[0040] The polishing composition for semiconductor processes according to an embodiment includes polishing particles and a surfactant.

[0041] 3 L of the semiconductor process polishing composition was stirred at 1000 RPM for 30 minutes at 25° C. and allowed to stand for 10 minutes. The volume of bubbles measured was 50 mL or less.

[0042] The polishing composition for semiconductor processes may be applied with a surfactant to adjust the affinity of the polishing composition to the surface to be polished and inhibit the adsorption of polishing particles and organic particles on the surface to be polished. However, the polishing composition containing a surfactant may form a plurality of bubbles during the supply process or the polishing process. The plurality of bubbles excessively increase the volume of the polishing composition, which may cause problems during the process of feeding the polishing composition, and may cause the polishing particles to aggregate during the polishing process, which may become a factor in the formation of scratches on the surface to be polished.

[0043] The embodiments can control bubble-related properties of the polishing composition containing a surfactant, effectively improve the convenience of CMP-related processes, and effectively inhibit the occurrence of defects on the polished surface caused by agglomeration and adsorption of polishing particles.

[0044] The volume of the bubbles is measured as follows.

[0045] 3L of the polishing composition for semiconductor process was put into a glass reactor with a volume of 5L. The polishing composition was stirred at 25°C at a speed of 1000RPM for 30 minutes using a 10cm long four-blade blade. The blades commonly used in the field of stirrers are suitable. After 10 minutes from the time when the stirring was ended, the height of the bubbles formed in the glass reactor was measured. The volume of the bubbles was calculated from the height value and the inner diameter of the container containing the polishing composition.

[0046] 3L of the semiconductor process polishing composition is stirred at 1000RPM for 30 minutes at 25°C, and the volume of the bubbles measured after standing for 10 minutes can be 50mL or less. The volume of the bubbles can be 40mL or less. The volume of the bubbles can be 30mL or less. The volume of the bubbles can be 1mL or more. In this case, the polishing composition can be easily put into the polishing object, which can contribute to suppressing the agglomeration of polishing particles during the polishing process.

[0047] The viscosity of the polishing composition for a semiconductor process may be 0.7 cP to 1.5 cP at 25°C.

[0048] The embodiments can help to adjust the viscosity of the polishing composition within the range preset in the embodiments, effectively reduce the amount of bubbles generated in the polishing composition containing a surfactant, and make the generated bubbles disappear quickly. In addition, adjusting the viscosity within the range preset in the embodiments can contribute to the polishing composition having a stable polishing rate for the polished surface for a long time.

[0049] The viscosity of the polishing composition is measured by a viscometer.

[0050] The viscosity of the polishing composition for semiconductor process at 25° C. may be 0.7 cP to 1.5 cP. The above viscosity may be 0.8 cP or more. The above viscosity may be 0.9 cP or more. The above viscosity may be 1.3 cP or less. The above viscosity may be 1.1 cP or less. This can help prevent excessive foaming during the polishing process, etc., while maintaining a stable polishing rate of the polished surface.

[0051] The polishing composition for a semiconductor process may have a dynamic surface tension of 25 mN / m to 70 mN / m at a bubble life of 10 seconds.

[0052] The polishing composition of the embodiment can present a relatively adjusted dynamic surface tension within a relatively short bubble life. Even if the polishing composition moves frequently due to the relative movement between the substrate and the polishing pad, it can present excellent affinity to the organic particles on the substrate surface and the substrate. At the same time, it can help to suppress the generation of excessive bubbles in the polishing composition during the polishing process.

[0053] The dynamic surface tension of the polishing composition is measured by the maximum bubble pressure method using a bubble pressure meter. The maximum bubble pressure method is a method in which the polishing composition to be measured is inserted into a capillary, gas is injected into the capillary, the internal pressure of the bubble formed at the end of the capillary is measured, and the dynamic surface tension is calculated from the measured value. In the maximum bubble pressure method, the bubble life means the time required from the formation of the bubble at the end of the capillary to the internal pressure of the bubble reaching the maximum.

[0054] When measuring the dynamic surface tension, the time interval is 1 second and the sample volume is 2 mL. For example, the bubble pressure measuring instrument can be the BPA-1P model of Sinterface Tech.

[0055] The dynamic surface tension of the polishing composition for semiconductor process can be 25mN / m to 70mN / m when the bubble life is 10 seconds. The above dynamic surface tension can be 69mN / m or less. The above dynamic surface tension can be 68mN / m or less. The above dynamic surface tension can be 30mN / m or more. The above dynamic surface tension can be 32mN / m or more. The above dynamic surface tension can be 34mN / m or more. When the polishing composition having the above characteristics is applied to the CMP process, a polished surface with improved flatness can be provided, and the amount of bubbles that may occur during the polishing process can be stably adjusted.

[0056] The pH of the polishing composition for semiconductor process may be 2 to 5. The pH may be 2.5 or more. The pH may be 3.0 or more. The pH may be 4.8 or less. The pH may be 4.6 or less. The pH may be 4.4 or less. The pH may be 4.2 or less. In this case, the polishing composition may exhibit excellent polishing properties for the polished surface including the silicon oxide film, and may help to stably disperse the polishing particles.

[0057] The pH of the polishing composition for semiconductor process is measured by a pH meter.

[0058] The zeta potential of the polishing composition for semiconductor process may be +10 mV to +50 mV. The zeta potential may be above +15 mV. The zeta potential may be above +20 mV. The zeta potential may be below +45 mV.

[0059] The zeta potential of the polishing particles may be between +10 mV and +50 mV. The zeta potential may be above +15 mV. The zeta potential may be above +20 mV. The zeta potential may be below +45 mV.

[0060] The zeta potential of the polishing composition for a semiconductor process and the polishing particles is measured under the condition that the pH of the polishing composition for a semiconductor process is 2.0 to 5.0.

[0061] In this case, the polishing composition can exhibit stable dispersibility and excellent polishing characteristics for a silicon oxide film having a negative surface charge.

[0062] Composition of polishing composition

[0063] Polishing particles

[0064] The polishing composition can contain polishing particles.

[0065] The polishing particles may include metal oxide particles and / or silicon oxide particles. The polishing particles may include silicon dioxide. The polishing particles may include colloidal silicon dioxide.

[0066] The polishing particles may contain more than 70 weight percent of colloidal silica. The polishing particles may contain more than 80 weight percent of colloidal silica. The polishing particles may contain more than 90 weight percent of colloidal silica. The polishing particles may be colloidal silica.

[0067] The surface of the polishing particle may have a positive charge. The polishing particle may be surface-modified in such a way that the surface has a positive charge. The polishing particle may be surface-modified by a compound having an amine group. The polishing particle may be surface-modified by an aminosilane.

[0068] The polishing particles may have a positive charge on the surface under the condition that the pH of the polishing composition for a semiconductor process is 2.0 to 5.0.

[0069] The aminosilane may be selected from 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- , one of the group consisting of 2-ethylenediamine, N-[3-(triethoxysilyl)propyl]ethylenediamine, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylaminomethyltriethoxysilane, diethylaminopropyltrimethoxysilane, diethylaminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]butylamine and combinations thereof.

[0070] The polishing composition for semiconductor process may contain 50ppm (weight basis) to 300ppm (weight basis) of aminosilane. The polishing composition for semiconductor process may contain 70ppm (weight basis) or more of aminosilane. The polishing composition for semiconductor process may contain 100ppm (weight basis) or more of aminosilane. The polishing composition for semiconductor process may contain 120ppm (weight basis) or more of aminosilane. The polishing composition for semiconductor process may contain 250ppm (weight basis) or less of aminosilane. The polishing composition for semiconductor process may contain 220ppm (weight basis) or less of aminosilane. The polishing composition for semiconductor process may contain 200ppm (weight basis) or less of aminosilane. The polishing composition for semiconductor process may contain 180ppm (weight basis) or less of aminosilane. In this case, the polishing composition has a better polishing rate for silicon oxide film, can polish the surface of the substrate to be polished more smoothly, and can show improved dispersibility. At the same time, the occurrence of residues of the surface modifier can be effectively suppressed, and the above residues are adsorbed on the polished surface.

[0071] The polishing composition for semiconductor process may contain 1 weight percent to 10 weight percent of polishing particles. The polishing composition for semiconductor process may contain more than 2 weight percent of polishing particles. The polishing composition for semiconductor process may contain less than 8 weight percent of polishing particles. The polishing composition for semiconductor process may contain less than 5 weight percent of polishing particles. In this case, the polishing composition may have an excellent polishing rate for the polished surface while stably suppressing the aggregation of the polishing particles.

[0072] The average particle size of the polishing particles may be greater than 20 nm. The particle size may be greater than 30 nm. The particle size may be greater than 40 nm. The particle size may be less than 70 nm. The particle size may be less than 60 nm. The particle size may be less than 50 nm. In this case, the polishing composition may exhibit an excellent polishing rate for the polished surface while stably adjusting the frequency of defects occurring on the polished surface.

[0073] The above average particle size means the average particle size of primary particles of the above polishing particles.

[0074] Surfactants

[0075] The polishing composition for semiconductor process contains a surfactant. The surfactant can improve the affinity of the polishing composition to the silicon oxide film and make the polishing composition evenly distributed on the polished surface during the polishing process.

[0076] The surfactant may be a nonionic surfactant. The nonionic surfactant adheres to the surface of the polished surface with appropriate strength, which can effectively prevent the polishing particles with positive surface charge from being adsorbed on the surface of the polished surface, and is also easy to be removed from the surface of the substrate after polishing.

[0077] The nonionic surfactant may include a first nonionic surfactant having a hydrophilic-lipophilic balance (HLB) value of 10 or more.

[0078] The HLB value of nonionic surfactants can be calculated using the following formula 1.

[0079] Formula 1

[0080]

[0081] In the above formula 1, Mh is the molecular weight of the hydrophilic part of the nonionic surfactant, and M is the molecular weight of the nonionic surfactant.

[0082] The first nonionic surfactant has a relatively high hydrophilicity and can effectively remove organic particles present on the surface of the substrate to be polished.

[0083] The polishing composition for semiconductor process may contain 1 part by weight or more of the first nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 3 parts by weight or more of the first nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 5 parts by weight or more of the first nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 25 parts by weight or less of the first nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 20 parts by weight or less of the first nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 15 parts by weight or less of the first nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant.

[0084] In this case, the adsorption of polishing particles and organic matter on the surface of the polished surface can be effectively suppressed.

[0085] The nonionic surfactant may include a second nonionic surfactant having an HLB value of 8 or less.

[0086] The second nonionic surfactant has a relatively high lipophilicity and, in addition to the functions described above, can also function as a defoamer in the polishing composition, thereby helping to suppress the generation of bubbles in the polishing composition.

[0087] The polishing composition for semiconductor process may contain 20 parts by weight or more of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 25 parts by weight or more of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 30 parts by weight or more of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 35 parts by weight or more of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 75 parts by weight or less of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 70 parts by weight or less of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for semiconductor process may contain 65 parts by weight or less of the second nonionic surfactant relative to 100 parts by weight of the total nonionic surfactant. The polishing composition for a semiconductor process may contain 60 parts by weight or less of the second nonionic surfactant based on 100 parts by weight of the entire nonionic surfactant.

[0088] In this case, it can contribute to effectively reducing the amount of bubbles generated during the supply of the polishing composition through the pipeline or during the polishing.

[0089] The nonionic surfactant may include both the first nonionic surfactant and the second nonionic surfactant, thereby simultaneously imparting the effects of the respective surfactants described above to the polishing composition.

[0090] The contents of the first nonionic surfactant and the second nonionic surfactant can be measured using a high performance liquid chromatography mass spectrometer (HPLC-MS).

[0091] The nonionic surfactant may include other nonionic surfactants in addition to the first nonionic surfactant and the second nonionic surfactant. For example, the nonionic surfactant may include a nonionic surfactant having an HLB value greater than 8 and less than 10.

[0092] The surfactant may include a polymer surfactant. The polymer surfactant may have a weight average molecular weight of 150 g / mol to 3000 g / mol.

[0093] In the embodiment, a polymer surfactant with an adjusted chain length can be applied to the polishing composition. Thus, the surfactant adsorbed on the polished surface can be effectively prevented from causing a decrease in the polishing rate of the polishing composition on the polished surface. In addition, the viscosity of the polishing composition can be adjusted within a stable range.

[0094] The weight average molecular weight of the polymer surfactant is measured by gel permeation chromatography (GPC).

[0095] The weight average molecular weight of the polymer surfactant may be 150 g / mol to 3000 g / mol. The weight average molecular weight may be 300 g / mol or more. The weight average molecular weight may be 500 g / mol or more. The weight average molecular weight may be 2500 g / mol or less. The weight average molecular weight may be 2000 g / mol or less. The weight average molecular weight may be 1500 g / mol or less. In this case, the affinity of the polishing composition for the silicon oxide film can be effectively improved, while the polishing rate of the polishing composition for the silicon oxide film can be stably adjusted. Moreover, when the weight average molecular weight is adjusted in the above manner, the occurrence of excessive bubbles as the viscosity of the polishing composition increases can be effectively suppressed.

[0096] The surfactant may be a fluorine-based surfactant. The surfactant may be a fluoroalkyl alkylene oxide-based compound. The surfactant may be a compound according to the following Chemical Formula 1.

[0097] Chemical formula 1

[0098] R f -(R n -0) x -H

[0099] In the above chemical formula 1, the above R f is a fluoroalkyl group having 3 to 10 carbon atoms, wherein R n is an alkylene group having 2 or 3 carbon atoms, and x is an integer of 2 to 15.

[0100] In the above chemical formula 1, R f The perfluoroalkyl group may be a group having 3 to 10 carbon atoms.

[0101] Illustrative surfactants include 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, and the like.

[0102] The surfactant having the structure of Chemical Formula 1 can be classified as a first nonionic surfactant or a second nonionic surfactant according to the HLB value. Among the surfactants having the structure of Chemical Formula 1, there may be one that is not equivalent to the first nonionic surfactant or the second nonionic surfactant according to the HLB value. For example, for F-(CF2)6-(C H2CH2O)3H, the HLB value is about 5.88, which is equivalent to the second nonionic surfactant, and for F-(CF2)6-(CH2CH2O)8H, the HLB value is about 10.51, which is equivalent to the first nonionic surfactant.

[0103] The polishing composition for semiconductor process may contain more than 10 ppm of surfactant. The polishing composition for semiconductor process may contain more than 20 ppm of surfactant. The polishing composition for semiconductor process may contain more than 50 ppm of surfactant. The polishing composition for semiconductor process may contain more than 100 ppm of surfactant. The polishing composition for semiconductor process may contain more than 150 ppm of surfactant. The polishing composition for semiconductor process may contain less than 500 ppm of surfactant. The polishing composition for semiconductor process may contain less than 450 ppm of surfactant. In this case, the affinity of the polishing composition to the polished surface can be effectively improved, while suppressing the occurrence of excessive foam during the polishing process.

[0104] Defoaming agent

[0105] The polishing composition for semiconductor process may further contain a defoaming agent. The defoaming agent is a substance different from the above-mentioned surfactant.

[0106] The defoaming agent is a substance that suppresses the generation of bubbles in the polishing composition when an external force acts on the polishing composition.

[0107] The defoaming agent may include a water-soluble polymer, which can be evenly distributed in the polishing composition without excessively increasing the viscosity of the composition, thereby effectively inhibiting the generation of bubbles in the polishing composition.

[0108] The water-soluble polymer may include a polyglycerol compound.

[0109] The polyglycerol-based compound means polyglycerol and its derivatives. Examples of the polyglycerol-based compound include polyglycerol-3, polyglycerol-4, polyglycerol-5, polyglycerol-10, and polyglycerol-20.

[0110] The weight average molecular weight of the water-soluble polymer may be 200 g / mol to 2000 g / mol. The weight average molecular weight may be 500 g / mol or more. The weight average molecular weight may be 1500 g / mol or less. The weight average molecular weight may be 1200 g / mol or less. In this case, the formation of bubbles that may occur during the polishing process can be effectively suppressed, which can help to stably disperse the polishing particles.

[0111] The weight average molecular weight of the water-soluble polymer is measured by gel permeation chromatography (GPC).

[0112] The polishing composition for semiconductor process may contain 0.001 weight percent or more of a defoaming agent. The polishing composition for semiconductor process may contain 0.003 weight percent or more of a defoaming agent. The polishing composition for semiconductor process may contain 0.005 weight percent or more of a defoaming agent. The polishing composition for semiconductor process may contain 0.1 weight percent or less of a defoaming agent. The polishing composition for semiconductor process may contain 0.08 weight percent or less of a defoaming agent. The polishing composition for semiconductor process may contain 0.05 weight percent or less of a defoaming agent. The polishing composition for semiconductor process may contain 0.03 weight percent or less of a defoaming agent. In this case, the generation of bubbles in the polishing composition during the polishing process can be suppressed, effectively improving the convenience of the polishing process.

[0113] Other additives

[0114] The semiconductor process polishing composition may further include other additives. As additives, there is no limitation as long as they are generally applicable in the CMP field. Illustratively, the additive may be at least one of a chelating agent, an oxidizing agent, an acid component, a pH adjusting agent, a dispersant, a polishing rate enhancer, a polishing adjusting agent, a polishing pad protective agent, and a preservative.

[0115] The polishing composition for semiconductor process may also contain a chelating agent. The metal or metal ions removed from the substrate surface by the polishing process may reattach or remain on the substrate surface to form defects. In particular, metals such as tungsten can be easily dissolved in the polishing composition under certain conditions, but may have the characteristic of being easily attached to the surface of the polishing object. The chelating agent can be adsorbed on such metals or metal ions, making it easy to remove the above metals, etc. As a result, the polishing rate of the polishing composition can be further improved, and the formation of defects on the substrate surface caused by the reattachment of particles can be effectively suppressed.

[0116] Illustratively, 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, glycolic acid, thioglycolic 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 acids and ethylenediaminetetraacetic acid.

[0117] As the amino acid, glycine, α-alanine, β-alanine, L-aspartic acid, N-methylglycine (methylglycine), and combinations thereof can be used.

[0118] The chelating agent may contain two or more carboxyl groups or alcohol groups in the molecule. As a chelating agent, two or more cases in which two or more carboxyl groups or alcohol groups are contained in the molecule may be applicable. Specifically, the above-mentioned chelating agent may contain one selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), glycine, carboxylic acids and combinations thereof. The above-mentioned carboxylic acids mean compounds containing at least one or more carboxyl groups in the molecule.

[0119] The polishing composition for semiconductor process may contain 0.003 weight percent to 0.5 weight percent of chelating agent. The polishing composition for semiconductor process may contain 0.005 weight percent or more of chelating agent. The polishing composition for semiconductor process may contain 0.3 weight percent or less of chelating agent. In this case, the polishing rate of the polishing composition can be controlled at an appropriate level, and the frequency of surface defects of the substrate can be reduced.

[0120] The polishing composition for semiconductor processes may further contain an oxidizing agent. The oxidizing agent can oxidize metals such as tungsten, thereby creating an environment in which the substrate surface can be more easily planarized, thereby increasing the polishing rate and etching rate.

[0121] The oxidizing agent can be at least one selected from the group consisting of hydrogen peroxide, urea hydrogen peroxide, urea, percarbonate, periodic acid, periodate, perchloric acid, perchlorate, perbromic acid, perbromate, perboric acid, perborate, permanganic acid, permanganate, persulfate, bromate, chlorate, chlorite, chromate, iodate, iodic acid, ammonium persulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide and urea peroxide.

[0122] The polishing composition for semiconductor processes may contain 0.01 wt % to 5 wt % of an oxidizing agent. In this case, the composition may exhibit excellent polishing properties for metals and inhibit the formation of an oxide film on the metal to be polished during the polishing process.

[0123] The polishing composition for semiconductor process may further include a copper corrosion inhibitor. The copper corrosion inhibitor may include an azole compound.

[0124] The azole compound may illustratively include one selected from the group consisting of benzotriazole (BT A), 5-Methyl-1H-Benzotriazole (5-MBTA), 3-Amino-1,2,4-Triazole, 5-Phen yl-1H-Tetrazole, 3-Amino-5-Methyl-4H-1,2,4-Triazole, 5-Aminotetrazole (ATZ), 1,2,4-Triazole, 5-Tolytriazole, and combinations thereof.

[0125] The azole compound may include one selected from the group consisting of 5-aminotetrazole (ATZ), 5-methyl-1H-benzotriazole (5-MBTA), and a combination thereof.

[0126] Azole compounds can act on the copper surface during the polishing process to prevent copper corrosion.

[0127] The azole compound may include 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.

[0128] When the azole compound is contained in such a range, the anticorrosion effect of the composition for semiconductor processes on the copper surface can be obtained, and in particular, a stronger anticorrosion effect can be provided on a relatively wide surface such as a through-hole surface.

[0129] The polishing composition for semiconductor process may further contain an acid component. The acid component may be illustratively 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, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, aspartic acid, tartaric acid and salts thereof.

[0130] The polishing composition for semiconductor processes may further contain a pH adjuster together with the acid component. The pH adjuster may be illustratively one selected from the group consisting of ammonia, aminomethyl propanol, tetramethyl ammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate, imidazole, and combinations thereof.

[0131] The polishing composition for semiconductor processes may further contain a dispersant.

[0132] The dispersant can prevent the agglomeration of the polishing particles in the polishing composition and make them dispersed uniformly. Cationic dispersants can increase the zeta potential of the polishing composition to a positive value, while anionic dispersants can reduce the zeta potential of the polishing composition to a negative value.

[0133] The dispersant may include anionic low molecular weight substances, cationic high molecular weight substances, organic acids, and the like.

[0134] The anionic low molecular weight of the dispersant may be at least one selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, and combinations thereof.

[0135] The cationic polymer of the dispersant can be one or more selected from polylysine, polyethyleneimine, benzethonium chloride, 5-bromo-5-nitro-1,3-dioxane (bronidox), hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dimethyldioctadecylammonium chloride, tetramethylammonium hydroxide, distearyldimethylammonium chloride, polyarylamine and combinations thereof.

[0136] The organic acid of the dispersant may be one or more selected from hydroxybenzoic acid, ascorbic acid, picolinic acid, glutamic acid, tryptophan, aminobutyric acid and a combination thereof.

[0137] The polishing rate enhancer is an additive for enhancing the polishing rate of a substrate or wiring to be polished, and may be one or more selected from potassium nitrate, ferric nitrate, ammonium hydroxide, citric acid, acetic acid, and combinations thereof.

[0138] The polishing conditioner is used to minimize the adsorption of the polishing composition on the metal surface, and may include ammonium compounds, potassium nitrate, amino acids, salts thereof, and the like.

[0139] The polishing composition for semiconductor process may contain a solvent. The solvent may be water, specifically, ultrapure water.

[0140] Polishing properties of polishing compositions

[0141] The polishing rate of the semiconductor process polishing composition for silicon oxide film can be The above polishing rate can be The above polishing rate can be The above polishing rate can be The above polishing rate can be The above polishing rate can be the following.

[0142] The polishing rate of the semiconductor process polishing composition for tungsten film can be The above polishing rate can be The above polishing rate can be The above polishing rate can be The above polishing rate can be the following.

[0143] In this case, the polishing composition can show an excellent selectivity ratio of the silicon oxide film polishing rate compared to the tungsten polishing rate.

[0144] The Ra value of the tungsten film measured after polishing for 30 seconds using the semiconductor process polishing composition 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 with a smoother surface.

[0145] The Ra value is determined according to ISO 4287.

[0146] Each film was polished under the conditions of a pressure of 2.2 psi, a carrier speed of 87 rpm, a platen speed of 93 rpm, and a slurry flow rate of 250 ml / min. The polishing pad used was SR-300 model from SK Enpulse.

[0147] When the polishing rate of each thin film is measured, the polishing machine may be exemplarily a CTS company AP-300 model.

[0148] Method for manufacturing substrate

[0149] The method for manufacturing a substrate of the embodiment includes a step of polishing a substrate using the polishing composition for a semiconductor process as a slurry.

[0150] The upper surface of the substrate may include at least one of an insulating film, a metal wiring and a barrier layer. The metal wiring may include copper or tungsten. When the metal wiring includes copper, the barrier layer may include tantalum and its nitride. When the metal wiring includes tungsten, the barrier layer may include titanium and its nitride.

[0151] Specifically, the process of polishing a substrate can be carried out by bringing the substrate to be polished into contact with the polishing pad together with the semiconductor process polishing composition supplied from a nozzle, and rotating the polishing head fixing the substrate and the plate to which the polishing pad is attached.

[0152] The process of polishing the substrate may further include a step of conditioning the surface of the polishing pad before polishing as required.

[0153] The polishing composition for semiconductor processes can polish a wafer in contact with the polishing pad while penetrating toward the substrate.

[0154] During the polishing of the substrate, a pressure of 6.89 kPa to 48.26 kPa may be applied. The pressure may be 13.79 kPa to 34.47 kPa.

[0155] The process of polishing the substrate can be carried out for 50 seconds to 10 minutes. It should be noted that the polishing degree can be changed according to the intended polishing degree.

[0156] The description of the polishing composition for the semiconductor process is repeated in the previous description and thus omitted.

[0157] The method for manufacturing a substrate may further include a cleaning process of cleaning the substrate after polishing.

[0158] The cleaning process can be performed by cleaning the polished substrate with purified water and an inert gas.

[0159] The following examples are only provided to help understand the present invention, and the scope of the present invention is not limited thereto.

[0160] Production Example: Production of Polishing Composition

[0161] Example 1: 3 weight percent of silica with an average diameter (primary particle basis) of 42 nm, surface-modified with (3-aminopropyl)triethoxysilane as polishing particles, and 100 ppm (weight basis) of a surfactant were mixed in ultrapure water as a solvent to prepare a polishing composition of 100 weight percent in total. The pH of the polishing composition was adjusted to 4.0.

[0162] The above-mentioned surfactant is suitable for fluorine-based surfactants. The above-mentioned surfactant is 100% by weight of the whole fluorine-based surfactant, and contains 28.2% by weight of F(CF2)6-(CH2-CH2O)2H and F(CF2) 6- (CH2-CH2O)3H, 20.5 weight percent of F(CF2)6-(CH2-CH2O)4H, 19.1 weight percent of F(CF2)6-(C H2-CH2O)5H, 14.65 weight percent of F(CF2)6-(CH2-CH2O)6H, 9.35 weight percent of F(CF2)6-(CH2-CH2O)7H, 4.95 weight percent of F(CF2)6-(CH2-CH2O)8H, 2.2 weight percent of F(CF2)6-(CH2-CH2O)9H, 0.85 weight percent of F(CF2)6-(CH2-CH2O) 10 H, 0.2 weight percent F(CF2)6-(CH2-CH2O) 11 H fluorinated surfactant.

[0163] Example 2: A polishing composition of 100 weight percent was prepared under the same conditions as in Example 1 except that it also contained 0.01 weight percent (excluding the corresponding content of ultrapure water) of polyglycerol having a weight average molecular weight of 750 g / mol.

[0164] Example 3: A polishing composition having a total weight of 100% was prepared under the same conditions as in Example 1 except that 30 ppm of the surfactant was used.

[0165] Comparative Example 1: A polishing composition of 100 weight percent was prepared under the same conditions as in Example 1 except that the nonionic surfactant was not used.

[0166] Comparative Example 2: A polishing composition of 100 weight percent was prepared under the same conditions as in Example 1 except that 1000 ppm of a nonionic surfactant was used.

[0167] Comparative Example 3: 2 weight percent of silicon dioxide with an average diameter (primary particle basis) of 45 nm as polishing particles without surface modification and nitric acid as a pH adjuster were added to ultrapure water as a solvent and mixed to prepare a polishing composition with a total of 100 weight percent. The pH of the polishing composition was adjusted to 3.8.

[0168] The contents of different components in the polishing compositions of the Examples and Comparative Examples, the zeta potentials of the polishing compositions, and the viscosities thereof are as described in the following Table 1.

[0169] Evaluation Example: Measurement of Bubble Generation Amount

[0170] 3 L of the polishing composition of the various embodiments and comparative examples was placed in a glass reactor with a volume of 5 L. The placed polishing composition was stirred at 1000 RPM for 30 minutes at 25° C. using a 10 cm long four-blade blade. Ten minutes after the stirring was stopped, the height of the bubbles formed in the glass reactor was measured. The volume of the bubbles was calculated from the height value and the inner diameter of the glass reactor containing the polishing composition.

[0171] The bubble volume values ​​calculated for different embodiments and comparative examples are recorded in Table 2 below.

[0172] Evaluation Example: Measurement of Dynamic Surface Tension of Polishing Composition

[0173] The dynamic surface tension of the polishing composition of Example 3 and Comparative Example 1 was measured by the maximum bubble pressure method using a bubble pressure measuring instrument BPA-1P from Sinterface Tech. When measuring the dynamic surface tension, the time interval was 1 second and the sample volume was 2 mL. The measured dynamic surface tension was measured as the value when the bubble life was 10 seconds.

[0174] The measured values ​​of different embodiments and comparative examples are recorded in Table 2 below.

[0175] Evaluation Example: Measurement of polishing rate of each thin film

[0176] Each polishing composition of Examples 1 to 3 and Comparative Examples 1 and 2 was applied as a slurry, and the polishing rate of a silicon oxide film and a tungsten film formed on a wafer having a diameter of 300 mm was measured. The polishing rate of each film was measured under the conditions of a polishing time of 60 seconds, a pressure of 2.2 psi, a carrier speed of 93 rpm, a platen speed of 87 rpm, and a slurry flow rate of 300 ml / min, and a CTS AP-300 model was used as a polisher.

[0177] The polishing rate measurement values ​​of the films of different embodiments and comparative examples are recorded in the following Table 3.

[0178] Evaluation Example: Determination of Defect Density on Polished Surface

[0179] The polishing compositions of Examples 1 to 3 and Comparative Examples 1 and 2 were used as slurries to polish a silicon oxide film formed on a wafer having a diameter of 300 mm. The silicon oxide film was polished under the same conditions as those used in the previous polishing rate measurement evaluation example.

[0180] The number of defects formed on the surface of the SiO2 wafer after polishing was measured using the AIT-XP+ model of KLA Tencor Corporation as a wafer defect inspector.

[0181] The measurement results of different embodiments and comparative examples are recorded in Table 3 below.

[0182] Table 1

[0183]

[0184] Table 2

[0185]

[0186] Table 3

[0187]

[0188]

[0189] The amount of bubbles generated was measured to be 30 mL or less in Examples 1 to 3, and 500 mL in Comparative Example 2. In particular, Example 2 using polyglycerol showed a lower amount of bubbles generated than Example 1 not using polyglycerol.

[0190] In terms of defect density on the polished surface, in Example and Comparative Example 2, the number of defects per wafer was measured to be less than 100, while in Comparative Example 1, the number of defects per wafer was measured to be greater than 850. This is because the polishing composition having a controlled contact angle with the silicon oxide film can be evenly distributed on the polished surface during the polishing process, and the surfactant effectively hinders the adsorption of polishing particles and organic particles on the polished surface.

[0191] The preferred embodiments are described in detail above, but the scope of the present invention is not limited thereto. Various modifications and improvements made by ordinary technicians in the technical field of the present invention using the basic concepts of the embodiments defined in the attached claims also fall within the scope of the present invention.

Claims

1. A polishing composition for semiconductor process, characterized in that: Contains polishing particles and surfactants, 3 L of the semiconductor process polishing composition was stirred at 1000 RPM at 25° C. for 30 minutes and allowed to stand for 10 minutes. The volume of bubbles measured was 50 mL or less.

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

3. The polishing composition for semiconductor process according to claim 1, characterized in that The dynamic surface tension at a bubble life of 10 seconds is 25 mN / m to 70 mN / m.

4. The polishing composition for semiconductor process according to claim 1, characterized in that The above surfactants include nonionic surfactants, The nonionic surfactant includes a first nonionic surfactant having a hydrophilic-lipophilic balance value of 10 or more.

5. The polishing composition for semiconductor process according to claim 1, characterized in that The above surfactants include nonionic surfactants, The nonionic surfactant includes a second nonionic surfactant having a hydrophile-lipophile balance value of 8 or less.

6. The polishing composition for semiconductor process according to claim 1, characterized in that The above-mentioned surfactant includes a polymer surfactant, The weight average molecular weight of the polymer surfactant is 150 g / mol to 3000 g / mol.

7. The polishing composition for semiconductor process according to claim 1, characterized in that Also contains defoaming agent, The defoaming agent contains a water-soluble polymer.

8. The polishing composition for semiconductor process according to claim 7, characterized in that The weight average molecular weight of the defoaming agent is 200 g / mol to 2000 g / mol.

9. The polishing composition for semiconductor process according to claim 7, characterized in that The defoaming agent contains a polyglycerol compound.

10. The polishing composition for semiconductor process according to claim 1, characterized in that The pH is between 2 and 5.

11. The polishing composition for semiconductor process according to claim 1, characterized in that The surfaces of the polishing particles have positive charges.

12. A method for manufacturing a substrate, characterized in that: The method comprises the step of applying the polishing composition for semiconductor process according to claim 1 as a slurry to polish a substrate.

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