Polishing composition for semiconductor process, method for preparing polishing composition, and method for manufacturing semiconductor device using polishing composition

Abstract

The present invention relates to a polishing composition for semiconductor process, a method for preparing the polishing composition, and a method for manufacturing a semiconductor device using the polishing composition, and more particularly, to a polishing composition for polishing an amorphous carbon layer (ACL), which can exhibit a high polishing rate for the amorphous carbon layer, does not have a problem of a decrease in polishing rate at 45°C or higher, has increased long-term storage stability, prevents carbon residue generated during the polishing process from being adsorbed on a semiconductor substrate, and prevents contamination of a polishing pad. In addition, the present invention can provide a method for manufacturing a semiconductor device using the polishing composition for semiconductor process.

Description

TECHNICAL FIELD

[0001] The present application relates to a polishing composition for semiconductor process, a method for preparing the polishing composition, and a method for manufacturing a semiconductor device. BACKGROUND

[0002] As semiconductor devices are more miniaturized and high-density, more fine patterning techniques are being used, and as a result, the surface structure of semiconductor devices becomes more complex, and the step difference of interlayer films is further increased. In terms of the manufacturing process of semiconductor devices, as a planarization technique for removing the step difference of a specific film formed on a substrate, a chemical mechanical polishing (hereinafter referred to as "CMP") process is used.

[0003] In the CMP process, a slurry is provided on a polishing pad, and at the same time, the substrate is pressurized and rotated, thereby achieving polishing of the surface thereof. The object to be planarized differs depending on the process step, and the physical properties of the slurry used at this time also differ.

[0004] Specifically, the CMP process is not only applied to the planarization of dielectrics such as silicon oxide (SiO2) and silicon nitride (SiN), but is also necessarily used in the planarization process of metal wiring such as tungsten (W) and copper (Cu).

[0005] As semiconductor devices are highly integrated, it is necessary to form a more fine pattern and a circuit having a multilayer structure, etc.

[0006] For this reason, a film of a plurality of substances having different etching selectivity characteristics is required. Among these films of a plurality of substances, a carbon-based organic film has good etching selectivity characteristics with respect to other silicon-containing films, and can be used as a mask film or a sacrificial film.

[0007] In a semiconductor manufacturing process, it is necessary to remove an organic film by a chemical mechanical polishing process. However, a polishing composition capable of effectively polishing an organic film applied to a semiconductor manufacturing process by applying a CMP process has not been developed.

[0008] Therefore, there is a need to develop a polishing composition for semiconductor process capable of solving the above problems. SUMMARY

[0009] Problem to be solved by the invention

[0010] The present application relates to a polishing composition for semiconductor process, a method for preparing the polishing composition, and a method for manufacturing a semiconductor device.

[0011] Another object of the present application is to provide a preparation method of a polishing composition for semiconductor processes, in which the polishing composition can exhibit a high polishing rate and prevent defects from occurring in a polishing process, by stabilizing an accelerator in the polishing composition as a composition including a stabilizer.

[0012] Another object of the present application is to provide a polishing composition for semiconductor processes, in which the polishing composition can be applied to a polishing process of an amorphous carbon layer, can exhibit a high polishing rate, and can prevent carbon residue generated in the polishing process from being adsorbed on a semiconductor substrate and also prevent contamination of a polishing pad.

[0013] Another object of the present application is to provide a method of manufacturing a semiconductor device using a polishing composition for semiconductor processes.

[0014] Means for solving the problem

[0015] To achieve the above object, a polishing composition for semiconductor processes according to an embodiment of the present application includes polishing particles, an accelerator, and a stabilizer, and the stabilizer can be a compound represented by the following Chemical Formula 1.

[0016] [Chemical Formula 1]

[0017]

[0018] wherein R1 to R3 are the same as or different from each other, and each is independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and R1 to R3 can each independently form a ring by bonding with an adjacent group.

[0019] A preparation method of a polishing composition for semiconductor processes according to another embodiment of the present application can include the steps of: step a) adding a stabilizer and an accelerator in a solvent and mixing to prepare a polishing solution; step b) adding a pH adjuster to the polishing solution to adjust the pH of the polishing solution to 2 to 5; and step c) mixing a surfactant and polishing particles in the polishing solution having a pH of 2 to 5.

[0020] The method of manufacturing a semiconductor device according to another embodiment of the present application can include the steps of: Step 1) providing a polishing pad including a polishing layer; Step 2) supplying a polishing composition for semiconductor processing to the polishing pad; Step 3) relatively rotating the polishing object in such a manner that the polishing surface of the polishing object is in contact with the polishing surface of the polishing layer, thereby polishing the polishing object. And, the polishing composition can include polishing particles, an accelerator, and a stabilizer.

[0021] Effects of the invention

[0022] The present application relates to a polishing composition for use in a polishing process of an amorphous carbon layer, which can exhibit a high polishing rate with respect to the amorphous carbon layer, and prevent carbon residue generated in the polishing process from being adsorbed on a semiconductor substrate, and also prevent contamination of a polishing pad.

[0023] Further, a method of manufacturing a semiconductor device using the polishing composition for semiconductor processing can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a schematic process diagram of a semiconductor device manufacturing process according to an embodiment of the present application.

[0025] Explanation of reference numerals

[0026] 110: Polishing pad

[0027] 120: Flat plate

[0028] 130: Semiconductor substrate

[0029] 140: Nozzle

[0030] 150: Polishing slurry

[0031] 160: Polishing head

[0032] 170: Trimmer DETAILED DESCRIPTION

[0033] The present application relates to a polishing composition for semiconductor processing, which includes polishing particles, an accelerator, and a stabilizer, and the stabilizer is a compound represented by Formula 1 below:

[0034] [Chemical Formula 1]

[0035]

[0036] wherein R1to R3are the same as or different from each other, and each is independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and the R1to R3may each independently form a ring by bonding with an adjacent group. Specific embodiments

[0038] Hereinafter, embodiments of the present application will be described in detail so as to allow those skilled in the art to easily practice the present application. The present application may, however, be embodied in various ways, and thus should not be construed as being limited to only the embodiments set forth herein.

[0039] In the present specification, unless otherwise specified, the expression that a certain component "comprises" another component means that still another component can be included but does not exclude the other components.

[0040] In the present specification, when it is referred to that a certain structure is "connected" to another component, this includes not only the case where it is "directly connected" but also the case where it is "connected with another component interposed therebetween".

[0041] In the present specification, the expression that B is "on" A means that B is on A in a manner of directly contacting or B is on A with another layer interposed therebetween, i.e., should not be construed only in the meaning that B is on the surface of A in a manner of contacting.

[0042] In the present specification, the term "mixtures thereof" included in the Markush description means a mixture or combination of one or more selected from the group consisting of the plurality of components described in the Markush description, and thus indicates the inclusion of one or more selected from the group consisting of the above plurality of components.

[0043] In the present specification, the expression "A and / or B" means "A, B, or A and B".

[0044] In the present specification, unless otherwise specified, terms such as "first", "second", or "A", "B", etc. are used to distinguish the same terms from each other.

[0045] In the present specification, unless otherwise specified, the singular expression can be construed to include the meaning of the singular or the plural, which can be interpreted from the context.

[0046] In the present specification, "hydrogen" is hydrogen, protium, deuterium, or tritium.

[0047] In the present specification, "alkyl" refers to a monovalent substituent derived from a straight chain or branched chain saturated hydrocarbon having 1 to 40 carbon atoms. As examples thereof, there can be mentioned methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, isopentyl, hexyl and the like, but are not limited thereto.

[0048] In the present specification, "alkenyl" refers to a monovalent substituent derived from a straight chain or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms having one or more carbon-carbon double bonds. As examples thereof, there can be mentioned vinyl, allyl, isopropenyl, 2-butenyl and the like, but are not limited thereto.

[0049] In the present specification, "alkynyl" refers to a monovalent substituent derived from a straight chain or branched chain unsaturated hydrocarbon having 2 to 40 carbon atoms having one or more carbon-carbon triple bonds. As examples thereof, there can be mentioned ethynyl, 2-propynyl and the like, but are not limited thereto.

[0050] In the present specification, "cycloalkyl" refers to a monovalent substituent derived from a monocyclic or polycyclic non-aromatic hydrocarbon having 3 to 40 carbon atoms. As examples of such cycloalkyl groups, there can be mentioned cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, norbornyl, adamantine and the like, but are not limited thereto.

[0051] In the present specification, "aryl" refers to a monovalent substituent derived from an aromatic hydrocarbon having 6 to 60 carbon atoms composed of a single ring or two or more rings. Further, it can also include two or more rings simply pendant or fused to each other. As examples of such aryl groups, there can be mentioned phenyl, naphthyl, phenanthryl, anthryl, fluorenyl, dimethylfluorenyl and the like, but are not limited thereto.

[0052] In the present specification, "heteroaryl group" means a monovalent substituent derived from a mono- or poly-heteroaromatic hydrocarbon having 6 to 30 carbon atoms. In this case, at least one or more carbons, preferably 1 to 3 carbons, in the ring are replaced with a heteroatom such as N, O, S, or Se. In addition, a form in which two or more rings are pendant or fused to each other can also be included. As examples of such heteroaryl groups, 6-membered monocyclic rings such as pyridyl, pyrazinyl, pyrimidinyl, pyridazinyl, triazinyl, and the like; poly-heteroaromatic rings such as phenoxathienyl, indolizinyl, indolyl, purinyl, quinolyl, benzothiazole, carbazolyl, and the like; 2-furyl group; N-imidazolyl; 2-isoxazolyl; 2-pyridyl; 2-pyrimidyl; and the like, but not limited thereto.

[0053] In the present application, "bonded to form a ring with an adjacent group" means bonded to an adjacent group to form a substituted or unsubstituted aliphatic hydrocarbon ring, a substituted or unsubstituted aromatic hydrocarbon ring, a substituted or unsubstituted aliphatic heterocycle, a substituted or unsubstituted aromatic heterocycle, or a fused ring thereof.

[0054] In the present application, as examples of "aromatic hydrocarbon ring", phenyl, naphthyl, anthryl, and the like, but not limited thereto.

[0055] In the present application, "aliphatic heterocycle" means an aliphatic ring containing one or more heteroatoms.

[0056] In the present application, "aromatic heterocycle" means an aromatic ring containing one or more heteroatoms.

[0057] In the present application, "substituted" means that a hydrogen atom bonded to a carbon atom of a compound is replaced with another substituent, and there is no limitation as to the position of substitution as long as it is a position where a hydrogen atom is replaced (i.e., a position where a substituent can be replaced). Also, when two or more substituents are replaced, the two or more substituents can be the same as or different from each other. The substituent can be replaced with one or more substituents selected from the group consisting of hydrogen, cyano, nitro, halogen group, hydroxyl group, alkyl group having 1 to 30 carbon atoms, alkenyl group having 2 to 30 carbon atoms, alkynyl group having 2 to 24 carbon atoms, heteroalkyl group having 2 to 30 carbon atoms, aralkyl group having 6 to 30 carbon atoms, aryl group having 5 to 30 carbon atoms, heteroaryl group having 2 to 30 carbon atoms, heteroaralkyl group having 3 to 30 carbon atoms, alkoxy group having 1 to 30 carbon atoms, alkylamino group having 1 to 30 carbon atoms, arylamino group having 6 to 30 carbon atoms, aralkylamino group having 6 to 30 carbon atoms, and heteroarylamino group having 2 to 24 carbon atoms, but not limited to the above examples.

[0058] Hereinafter, the present application will be described in more detail.

[0059] As semiconductor devices are more miniaturized and high-density, surface structures become more complex. The complexity of the surface structure means that the line width of the semiconductor is narrowed, the aspect ratio gradually increases, and the photoresist is gradually thinned to adapt to the increasing aspect ratio.

[0060] However, the thinned and elongated photoresist cannot withstand the etching process and collapses, and in order to prevent this, a hard mask process is introduced.

[0061] As the hard mask material, amorphous carbon and SiON are used.

[0062] Although the amorphous carbon has excellent etching resistance when used as a hard mask, when applied to a chemical mechanical polishing process using a conventional polishing composition, the polishing rate is low and carbon residues are generated, causing the problem of defects in the semiconductor substrate due to the adsorption of the carbon residues on the surface of the thin film.

[0063] Therefore, the polishing composition for semiconductor processes according to the present application not only exhibits a high polishing rate for amorphous carbon films, but also prevents the re-adsorption of carbon residues and prevents defects in the semiconductor substrate.

[0064] Specifically, the polishing composition according to the present application comprises polishing particles, an accelerator, and a stabilizer, and the stabilizer is a compound represented by the following Chemical Formula 1:

[0065] [Chemical Formula 1]

[0066]

[0067] wherein R1 to R3 are the same as or different from each other, each is independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and R1 to R3 can each independently form a ring by bonding with adjacent groups.

[0068] The stabilizer is a component of the polishing composition, which is contained in the polishing composition together with the polishing particles and the accelerator, can prevent agglomeration of the polishing particles, and increases stability, so that excellent polishing performance can be maintained even after the polishing composition is used in the polishing process after long-term storage of the polishing composition.

[0069] The polishing composition of the present application can be used for polishing an amorphous carbon film (ACL).

[0070] A conventional polishing composition for polishing an amorphous carbon film has a low polishing rate, and thus has a problem of reduced polishing efficiency. When the amorphous carbon film is polished using the polishing composition in a semiconductor manufacturing process, the polishing rate for the amorphous carbon film can be 150 A / min to 250 A / min, preferably 150 A / min to 220 A / min, and more preferably 150 A / min to 210 A / min. In other words, in the case where the amorphous carbon film is polished using the polishing composition, when the polishing rate in the range is exhibited, the polishing efficiency is excellent, so that the polishing composition can be used in the polishing process.

[0071] To solve this problem, an accelerator is contained as one component of the polishing composition. As described above, when the polishing composition containing the accelerator is used in the polishing process for the amorphous carbon film, the polishing rate can be 150 A / min to 250 A / min.

[0072] However, when the polishing process is performed at 45°C or higher, a problem of a sharp decrease in the polishing rate occurs or a problem of a decrease in the polishing rate when stored for a long time occurs.

[0073] To prevent this problem, the polishing composition of the present application is characterized by containing a stabilizer represented by the above Chemical Formula 1. As described above, when the accelerator and the stabilizer are contained, a high polishing rate can be exhibited for the amorphous carbon film, and even when the polishing process is performed at 45°C or higher, a problem of a decrease in the polishing rate does not occur, and long-term storage stability can be maintained.

[0074] Specifically, the compound represented by the above Chemical Formula 1 can be a compound represented by the following Chemical Formula 2 or Chemical Formula 3:

[0075] [Chemical Formula 2]

[0076]

[0077] [Chemical Formula 3]

[0078]

[0079] wherein n is an integer of 0 to 4, R4and R5, which are the same as or different from each other, can each independently be selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, and a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms.

[0080] More specifically, R4is a methyl group, and n is 0, but not limited to the above examples, and any stabilizer is used without limitation as long as it is a stabilizer capable of stabilizing the accelerator when contained in the polishing composition, thereby preventing the agglomeration phenomenon, and also does not cause a problem of a decrease in polishing rate at 45°C or higher, and is capable of providing excellent long-term storage stability.

[0081] The polishing particles are, as polishing particles capable of being applied to a polishing composition for semiconductor processes, for example, selected from the group consisting of metal oxides, organic particles, organic-inorganic hybrid particles, and a mixture thereof. The metal oxides can be selected from the group consisting of colloidal silica, fumed silica, ceria, alumina, titania, zirconia, zeolite, and a mixture thereof, but not limited to the examples, and any metal oxide particle can be used without limitation as long as it is a metal oxide particle that can be selected by one skilled in the art.

[0082] The organic particles can be polystyrene, styrene-based copolymer, poly(meth)acrylate, (meth)acrylate-based copolymer, polyvinyl chloride, polyamide, polycarbonate, and polyimide polymer; or the polymers constitute particles of a core, a shell, or a core / shell structure of both, and they can be used alone or in a mixture, and the organic particles can be prepared by an emulsion polymerization method, a suspension polymerization method, or the like.

[0083] The polishing particles of the present application can specifically be selected from the group consisting of colloidal silica, fumed silica, ceria, and a mixture thereof.

[0084] The diameter (D 50 ) of the polishing particles can be 10 nm to 120 nm, preferably, the diameter (D 50 ) can be 20 nm to 100 nm, and more preferably, the diameter (D 50 ) can be 40 nm to 80 nm. When the polishing particles having the diameter size in the above range are contained in the polishing composition and used in the polishing process, it is possible to prevent defects such as scratches on the substrate as a polishing target, and excellent dispersibility can be obtained.

[0085] The accelerator can be selected from the group consisting of an anionic small molecule, an anionic polymer, a hydroxy acid, an amino acid, and a cerium salt. Specifically, the cerium salt can be a trivalent cerium salt or a tetravalent cerium salt, and more specifically, the tetravalent cerium salt can be selected from the group consisting of cerium sulfate (Ce(SO4)2), cerium ammonium sulfate dihydrate, and cerium ammonium nitrate (CAN), but is not limited to the examples.

[0086] The accelerator is contained in the polishing composition to make removal of the surface layer of the amorphous carbon film easier by oxidizing the surface layer of the amorphous carbon film into an oxide or ions.

[0087] Further, it has an advantage that residues of the organic film material present in the polishing stopper layer can be easily removed, thereby making the polishing more uniform.

[0088] The cerium ammonium nitrate can be present in the slurry composition in the form of an ionic compound or a chelate, and as described above, when contained in the form of an ionic compound or a chelate, can exhibit a high polishing rate with respect to the amorphous carbon film.

[0089] However, when only an accelerator is contained in order to increase the polishing rate of the amorphous carbon film, the stability of the polishing composition decreases, causing agglomeration between the particles, or when used in the polishing process after long-term storage or when the polishing process is performed at 45°C or higher, a problem of a decrease in the polishing rate can occur.

[0090] Therefore, in the case of the present application, it is characterized in that the polishing composition contains an accelerator represented by the above Chemical Formula 1 and a stabilizer. The accelerator can increase the polishing rate with respect to the amorphous carbon film, and the stabilizer is characterized in that it can increase the stability of the polishing composition, thereby preventing agglomeration between the particles, and can be stored for a long time, and even when polishing is performed at 45°C or higher, does not exhibit a decrease in the polishing rate.

[0091] The present application relates to a polishing composition having a value of less than 38%, preferably -10% to 15%, more preferably -5% to 5% according to the following Formula 1:

[0092] [Formula 1]

[0093]

[0094] wherein the RR0 is a polishing rate measured using the polishing composition under the following polishing conditions, the RR fis the polishing rate measured after the polishing composition is stored for 10 hours at 45°C, cooled at 15°C to 25°C, and then polished under the following polishing conditions. Among them, in terms of the polishing conditions, the temperature condition is 15°C to 25°C, the rotation speed of the polishing head is 87 rpm, the rotation speed of the flat plate is 93 rpm, the injection rate of the polishing composition is 90 ml / min, the polishing time is 60 seconds, the wafer is an amorphous carbon film wafer having a thickness of 2000 angstroms and a size of 4 cm x 4 cm in the lateral and longitudinal directions, and polishing is performed using a mini polisher. The RR0and RR f is the polishing rate converted by measuring the thickness of the amorphous carbon film before and after polishing under the polishing conditions.

[0095] The polishing composition of the present application has excellent stability, which means that the polishing performance is not affected by long-term storage. In particular, depending on whether a stabilizer is included as one component of the polishing composition, there is a large difference in storage stability.

[0096] In order to confirm the difference in storage stability, the polishing rate can be confirmed after long-term storage is used in the polishing process, but more simply, the polishing composition can be stored under harsh conditions and then used in the polishing process, and confirmation can be made by whether the polishing rate changes.

[0097] The formula 1 can confirm such storage stability. RR0is the polishing rate measured after the polishing composition is prepared and the polishing process is performed, and RR f is the polishing rate measured after the polishing composition is placed in an oven at 45°C and stored for 10 hours, then cooled, and the polishing process is performed.

[0098] As described above, placing the polishing composition in an oven at 45°C is to set harsh conditions, and by confirming whether the polishing composition remains stable under temperature conditions different from the conventional storage temperature, it is possible to indirectly confirm whether it can be stored for a long time. In other words, when storage for 1 hour at 45°C is equivalent to storage for one day at 15°C to 25°C, storage for 10 hours at 45°C can mean the polishing composition after about 10 days of storage.

[0099] According to the value of the above formula 1 included in the range of the present application, it means that even when the polishing composition is used in the polishing process after long-term storage after preparation, the polishing rate does not significantly decrease. Specifically, it means that even after storage for more than 10 days, the polishing rate does not change.

[0100] In addition, when the value according to the above formula 1 is included in the range of the present application, it means that even when the polishing process is performed in a high-temperature process at 45°C, a decrease in the polishing rate is not exhibited. In other words, for the RRf In other words, although it is after storage at 45°C for 10 hours and then cooling at 15°C to 25°C and then used in the polishing process, but when considering that the polishing composition also maintains stability in the state of storage at 45°C for 10 hours, it also means that even if the polishing process is performed under high temperature conditions, the polishing composition does not change and maintains stability, thereby exhibiting a high level of polishing rate.

[0101] For the polishing composition of the present application, even after 10 days, the polishing rate does not decrease, thereby being able to exhibit excellent effects on long-term storage stability. In contrast, unlike the present application, when the stabilizer is not included, there is no significant difference in the polishing rate at the initial stage of manufacture compared to the polishing composition including the stabilizer, but after 10 days, it can be confirmed that the polishing rate of the polishing composition not including the stabilizer is significantly decreased.

[0102] The polishing composition of the present application, as a composition including a surfactant, reduces the surface tension based on the surfactant, thereby preventing carbon residues from being re-adsorbed on the semiconductor substrate.

[0103] When an accelerator is included in the polishing composition in order to increase the polishing rate for amorphous carbon films, the polishing rate is increased, but there is a problem that carbon residues generated in the polishing process are adsorbed on the semiconductor substrate, resulting in an increase in defects.

[0104] In order to solve the above problem, the surface tension of the polishing composition is reduced by including a surfactant in the polishing composition, and based on the reduction of the surface tension, it is possible to prevent carbon residues from being re-adsorbed on the surface of the substrate.

[0105] Specifically, the surfactant can include a non-ionic fluorine-based high molecular compound. The surfactant includes a fluorine-based high molecular compound, and when used in the polishing process for amorphous carbon films, it is possible to prevent the generated carbon residues from being re-adsorbed on the surface of the semiconductor substrate.

[0106] In addition, since the surfactant contains fluorine, it is possible to inhibit the proliferation of microorganisms such as bacteria and mold. When the polishing composition is stored for a long time, bacteria and mold can proliferate, and the polishing composition in which the bacteria and mold proliferate cannot be used in the polishing process and must be discarded.

[0107] In the polishing composition of the present application, the surfactant includes a non-ionic fluorine-based high molecular compound, and thus, when the polishing composition is stored for a long time, it is possible to prevent the proliferation of bacteria and mold, thereby making it possible to improve long-term storage stability.

[0108] The surfactant of the present application can be specifically selected from the group consisting of FS-30, FS-31, FS-34, ET-3015, ET-3150, ET-3050 of Chemours tm ) Corporation, but as long as it is a substance capable of preventing the re-adsorption of carbon residues on the surface of the semiconductor substrate, it is not particularly limited.

[0109] The surfactant of the present application is a nonionic surfactant, and can be used alone including a nonionic fluorine-based high molecular compound, or in combination with other nonionic surfactants.

[0110] The nonionic surfactant can be selected from the group consisting of polyethylene glycol, polypropylene glycol, polyethylene-propylene copolymer, polyalkyl oxide, polyoxyethylene oxide (PEO), polyethylene oxide, and polypropylene oxide, and the fluorine-based surfactant can be selected from the group consisting of sodium sulfonate fluorosurfactant, phosphate ester fluorosurfactant, amine oxide fluorosurfactant, betaine fluorosurfactant, ammonium carboxylate fluorosurfactant, stearate ester fluorosurfactant, quaternary ammonium fluorosurfactant, ethylene oxide / propylene oxide fluorosurfactant, and polyoxyethylene fluorosurfactant.

[0111] The pH adjuster can be at least one selected from the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, nitric acid, bromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, stearic acid, acetic acid, propionic acid, fumaric acid, oleic 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 potassium hydroxide.

[0112] The pH adjuster can represent the pH of the polishing composition for semiconductor processes as 2 to 5, or preferably, as 2 to 4. When the acidic environment is maintained in this range, it is possible to maintain the polishing speed and quality at a certain level or more while preventing excessive corrosion of the metal component or the polishing device.

[0113] The polishing composition for semiconductor processes can include 0.1 to 0.5% by weight of polishing particles, 1 to 2% by weight of an accelerator, 1 to 2% by weight of a stabilizer, 0.001 to 0.01% by weight of a surfactant, and the remaining solvent. When the content of the polishing composition is within the above range, the accelerator becomes stable due to the stabilizer, thereby making it possible to improve the polishing rate based on the accelerator in the polishing composition, and making it possible to prevent the occurrence of defects in the polishing process due to the stabilizer and the surfactant.

[0114] The solvent is ultrapure water, but is not limited to the above example, and any solvent that can be used as a solvent of the polishing composition can be used without limitation.

[0115] The method of preparing the polishing composition according to the present application can include the steps of: step a) adding and mixing a stabilizer and an accelerator in a solvent, thereby preparing a polishing solution; step b) adding a pH adjuster to the polishing solution, thereby adjusting the pH of the polishing solution to 2 to 5; and step c) mixing a surfactant and polishing particles in the polishing solution having the pH of 2 to 5.

[0116] In the step a), for the stabilization of the accelerator, the stabilizer can be mixed in a solvent to prepare a mixed solution, and then the accelerator can be mixed in the mixed solution to prepare a polishing solution.

[0117] In the case of the accelerator, when the accelerator is prepared by mixing ultrapure water as a solvent with other stabilizers, pH adjusters, surfactants, and polishing particles, the accelerator is not stable in the polishing composition, making it difficult to be stored for a long time when the polishing composition is prepared, or can not exhibit the effect of improving the polishing rate based on the accelerator in the polishing composition.

[0118] To prevent such a problem, the present application prepares a mixed solution by mixing a stabilizer in a solvent, and then prepares a polishing solution by mixing an accelerator in the mixed solution. Subsequently, the pH value is adjusted to a suitable range, and a surfactant and a polishing particle are mixed, thereby preparing a polishing composition. When the polishing composition is prepared in the method as described above, the stability of the accelerator in the polishing composition can be maintained, thereby enabling long-term storage, and enabling prevention of a problem of a decrease in polishing rate when a polishing process is performed at a high temperature.

[0119] A method of manufacturing a semiconductor device according to another embodiment of the present application can include the steps of: Step 1) providing a polishing pad including a polishing layer; Step 2) supplying a polishing composition for a semiconductor process to the polishing pad; Step 3) relatively rotating the polishing pad and a polishing object in such a manner that a polishing surface of the polishing object is in contact with a polishing surface of the polishing layer, thereby polishing the polishing object. Also, the polishing composition can include a polishing particle, an accelerator, and a stabilizer, and the stabilizer can be a compound represented by Chemical Formula 1 below.

[0120] [Chemical Formula 1]

[0121]

[0122] wherein R1 to R3 are the same as or different from each other, and each is independently selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, and a substituted or unsubstituted heteroaryl group having 3 to 30 carbon atoms, and the R1 to R3 can each independently form a ring by bonding with an adjacent group. A detailed description of the stabilizer will be omitted.

[0123] Figure 1 is a schematic process diagram illustrating a semiconductor device manufacturing process according to an embodiment of the present application. Referring to Figure 1 After the polishing pad 110 according to an embodiment is mounted on the platen 120, a semiconductor substrate 130 as a polishing object is disposed on the polishing pad 110. To perform polishing, a polishing slurry 150 is sprayed onto the polishing pad 110 through a nozzle 140.

[0124] The flow rate of the polishing slurry 150 supplied through the nozzle 140 can be selected in a range of about 10 cm 3 / min to about 1000 cm 3 / min according to a purpose, for example, can be about 50 cm 3 / min to about 500 cm 3 / min, but not limited thereto.

[0125] The polished surface of the semiconductor substrate 130 is directly in contact with the polishing surface of the polishing pad 110.

[0126] Thereafter, the semiconductor substrate 130 and the polishing pad 110 are relatively rotated, thereby enabling polishing of the surface of the semiconductor substrate 130. At this time, the rotation direction of the semiconductor substrate 130 and the rotation direction of the polishing pad 110 can be the same or opposite. The rotation speed of the semiconductor substrate 130 and the polishing pad 110 can be selected in the range of about 10 rpm to about 500 rpm according to the purpose, for example, can be about 30 rpm to about 200 rpm, but not limited thereto.

[0127] As an example of the polishing process for the substrate, an organic film of the substrate is polished, which can be applied to a polishing process of a carbon-based organic film.

[0128] Specifically, as the carbon-based organic film, C-SOH (spin on hardmask) film, amorphous carbon layer, or NCP film can be exemplified, and the amorphous carbon layer is preferred, which has excellent selective polishing effect and can exhibit a high polishing rate.

[0129] The specific description of the polishing composition for semiconductor process is repeated with the above description, and thus the description thereof is omitted.

[0130] In an embodiment, in order to maintain the polishing surface of the polishing pad 110 in a state suitable for polishing, the semiconductor device manufacturing method can further include a step of processing the polishing surface of the polishing pad 110 by a dresser 170 while polishing the semiconductor substrate 130.

[0131] Preparation of semiconductor polishing composition

[0132] Example 1

[0133] As the polishing particles, colloidal silica was used. After preparing a mixed solution by mixing a stabilizer represented by Chemical Formula 4 below in ultrapure water, cerium ammonium nitrate was further mixed, thereby preparing a polishing solution.

[0134] In the polishing solution, nitric acid was mixed, thereby adjusting the pH to 2.1, and a surfactant FS-30 of Chemours Corporation and colloidal silica having a diameter of 75 nm were further mixed, thereby preparing a polishing composition. tm ) Corporation and colloidal silica having a diameter of 75 nm were further mixed, thereby preparing a polishing composition.

[0135] [Chemical Formula 4]

[0136]

[0137] Example 2

[0138] A polishing composition was prepared in the same manner as Example 1 except that a compound represented by the following Chemical Formula 5 was used as the stabilizer.

[0139] [Chemical Formula 5]

[0140]

[0141] Comparative Examples 1 to 12

[0142] A polishing composition was prepared in the same manner as Example 1 except that the kind of the stabilizer was different as shown in the following Table 1.

[0143] [Table 1]

[0144] Stabilizer species Comparative Example 1 Ammonium chloride Comparative Example 2 Hydrochloric acid Comparative Example 3 Histidine Comparative Example 4 Phosphoric acid Comparative Example 5 Formic acid Comparative Example 6 Ammonium phosphate Comparative Example 7 Citric acid Comparative Example 8 Tartaric acid Comparative Example 9 Malonic acid Comparative Example 10 Maleic acid Comparative Example 11 Oxalic acid

[0145] Comparative Example 12

[0146] A polishing composition was prepared in the same manner as Example 1 except that no stabilizer was contained.

[0147] Specifically, the content of each component of the Example 1, Example 2, and Comparative Examples 1 to 12 was as follows in Table 2.

[0148] [Table 2]

[0149]

[0150] (Unit: wt%)

[0151] Experimental Example 1

[0152] Polishing rate was measured

[0153] A polishing process was performed using the polishing compositions of the examples and comparative examples under the following polishing conditions. The polishing rate of the polishing process was measured, and the results were confirmed.

[0154] Polishing device: G&P POLI-400

[0155] Polishing pad: SKC PAD HD-319B

[0156] Polishing time: 60 seconds

[0157] Rotation speed of the polishing head: 87 rpm

[0158] Pressure of the polishing head: 210 g / cm 2

[0159] Trimmer pressure: 16.5 kgf

[0160] Trimmer RPM: 93 rpm

[0161] Flat plate rotation speed: 93 rpm

[0162] Polishing composition injection speed: 90 ml / min

[0163] Wafer: ACL wafer of 4 cm x 4 cm (2000 angstroms )

[0164] For the polishing conditions, polishing was performed using a mini polisher, and for the wafer weight before and after polishing, the thickness of the amorphous carbon film was measured using a thickness measuring device M-2000 ellipsometer of J.A. Woollam Co., and thus the polishing rate was converted. The measurement results are shown in Table 3.

[0165] [Table 3]

[0166]

[0167]

[0168] (Polishing rate unit: angstroms / min)

[0169] *: Polishing process was performed at 15 to 25°C

[0170] **: After keeping at 45°C for 10 hours, cooling at 15 to 25°C, and then performing the polishing process.

[0171] According to the above Table 3, the polishing rate of the polishing compositions of Comparative Examples 6 to 11 could not be measured due to aggregation.

[0172] In Example 1, Example 2, and Comparative Examples 1 to 5, when the polishing process was performed at 15 to 25°C (room temperature RR*), the polishing rate was 76 to 85 angstroms / min, and thus it was confirmed that there was no significant difference.

[0173] In the case where, after keeping at 45°C for 10 hours, cooling at 15 to 25°C, and then performing the polishing process (high temperature RR**), it was confirmed that Example 1 and Example 2 were 81 and 79 angstroms / min, and there was no difference in the polishing rate compared to the room temperature RR*.

[0174] In contrast, for Comparative Examples 1 to 5, the polishing rate value of the high temperature RR** was reduced by a minimum of 38% to a maximum of 62% compared to the room temperature RR*. That is, this means that the storage stability of the polishing compositions of Comparative Examples 1 to 5 is reduced.

[0175] Experimental Example 2

[0176] Evaluation of Storage Stability

[0177] The change in the polishing rate based on the long-term storage of the polishing composition was measured, and for Example 1 and Comparative Example 12, the polishing rate was measured after 1 day, 9 days, 15 days, 22 days and 29 days under the following conditions.

[0178] [Polishing Conditions]

[0179] Polishing device: AP-300

[0180] Polishing pad: HD-319B

[0181] Polishing time: 60 seconds

[0182] Rotation speed of the polishing head: 87 rpm

[0183] Rotation speed of the platen: 93 rpm

[0184] Injection speed of the polishing composition: 200 ml / min

[0185] Wafer: ACL wafer (2000 angstroms) 300 mm

[0186] Temperature condition: 15 to 25°C

[0187] The thickness change of the amorphous carbon film of the wafer before and after the polishing process was measured using the thickness measurement device M-2000 ellipsometer of J. A. Woollam, Inc., and the polishing rate was calculated.

[0188]

[0189] (Polishing rate unit: angstroms / minute)

[0190] According to Table 4 above, in contrast to the present application, when the stabilizer was not included, it was confirmed that the polishing rate was sharply reduced after 9 days. Specifically, at the time point of 15 days of storage after 9 days, the measured polishing rate was reduced by about 65% compared to the case of 9 days. In contrast, in the case of Example 1 of the present application, the polishing rate was slightly reduced at 15 days and 22 days after 9 days, but at the time point of 29 days, it was confirmed that the highest level of polishing rate was exhibited, so it can be said that this means that the polishing rate is not reduced due to long-term storage.

[0191] The preferred embodiments of the present application have been described in detail above, but the scope of the present application is not limited thereto, and various modifications and improvements thereof are possible within the scope of the basic concept of the present application defined in the claims.

[0192] Industrial applicability

[0193] The present application relates to a polishing composition for semiconductor processes, a method for preparing the polishing composition, and a method for manufacturing a semiconductor device using the polishing composition.

Claims

1. A polishing composition for semiconductor process, wherein, a polishing particle, an accelerator, and a stabilizer are contained, the accelerator contains a cerium salt, the stabilizer is a compound represented by the following Chemical Formula 2 or Chemical Formula 3, the polishing composition for semiconductor process has a value based on the following Formula 1 of less than 38%: [Chemical Formula 2] [Chemical Formula 3] wherein n is an integer of 0 to 4, R4 is selected from the group consisting of a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a pentyl group, an isopentyl group, a hexyl group, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, and a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, R5 is selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, and a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, [Formula 1] for the polishing conditions, the temperature condition is 15°C to 25°C, the rotation speed of the polishing head is 87 rpm, the rotation speed of the flat plate is 93 rpm, the injection rate of the polishing composition is 90 ml / min, the polishing time is 60 seconds, the wafer is an amorphous carbon film wafer having a thickness of 2000 angstroms, a horizontal and vertical size of 4 cm x 4 cm, and polishing is performed using a small polishing machine, 2. The polishing composition for semiconductor process according to claim 1, wherein, wherein the RR0 is a polishing rate determined using the polishing composition under the following polishing conditions, the RR f is a polishing rate determined after the polishing composition is stored at 45°C for 10 hours, cooled at 15°C to 25°C, and then under the following polishing conditions, the polishing particle is selected from the group consisting of a metal oxide, an organic particle, an organic-inorganic hybrid particle, and a mixture thereof. The RR0 and RR f The polishing rate is converted by measuring the thickness of the amorphous carbon film before and after polishing under the polishing conditions.

3. The polishing composition for semiconductor process according to claim 1, wherein, the accelerator is selected from the group consisting of an anionic small molecule, an anionic high molecule, a hydroxy acid, an amino acid, and a cerium salt.

4. The polishing composition for semiconductor process according to claim 1, wherein, the polishing composition contains a surfactant.

5. The polishing composition for semiconductor process according to claim 1, wherein, the polishing composition contains a pH adjustor. comprising the steps of: Step a) adding and mixing a stabilizer and an accelerator in a solvent, thereby preparing a polishing solution; 6. A method for preparing a composition for semiconductor processing, wherein, Step b) adding a pH adjustor to the polishing solution, thereby adjusting the pH of the polishing solution to 2 to 5; and Step c) mixing a surfactant and a polishing particle in the polishing solution having a pH of 2 to 5, the accelerator contains a cerium salt, the stabilizer is a compound represented by the following Chemical Formula 2 or Chemical Formula 3, the polishing composition for semiconductor process has a value based on the following Formula 1 of less than 38%: [Chemical Formula 2] [Chemical Formula 3] wherein n is an integer of 0 to 4, R4 is selected from the group consisting of a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a pentyl group, an isopentyl group, a hexyl group, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, and a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, R5 is selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, and a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, ​ ​ R5is selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having a carbon number of 1 to 10, a substituted or unsubstituted cycloalkyl group having a carbon number of 3 to 10, a substituted or unsubstituted alkenyl group having a carbon number of 2 to 10, and a substituted or unsubstituted alkynyl group having a carbon number of 2 to 10, [Formula 1] wherein the RR0 is a polishing rate determined using the polishing composition under the following polishing conditions, the RR f is a polishing rate determined after the polishing composition is stored at 45°C for 10 hours, cooled at 15°C to 25°C, and then under the following polishing conditions, For the polishing conditions, the temperature condition is 15°C to 25°C, the rotation speed of the polishing head is 87 rpm, the rotation speed of the platen is 93 rpm, the injection rate of the polishing composition is 90 ml / min, the polishing time is 60 seconds, the wafer is an amorphous carbon film wafer having a thickness of 2000 angstroms, a horizontal and vertical size of 4 cm x 4 cm, and polishing is performed using a small polishing machine, The RR0 and RR f The polishing rate is converted by measuring the thickness of the amorphous carbon film before and after polishing under the polishing conditions.

7. The method for producing a semiconductor process composition according to claim 6, wherein The step a) is: The stabilizer is mixed in a solvent to prepare a mixed solution, and then the accelerator is mixed in the mixed solution to prepare a polishing solution.

8. A method of manufacturing a semiconductor device, wherein, comprises the following steps: Step 1) providing a polishing pad including a polishing layer; Step 2) providing a polishing composition for semiconductor processes to the polishing pad; and Step 3) relatively rotating the polishing object in such a manner that the polished surface of the polishing object is in contact with the polishing surface of the polishing layer, thereby polishing the polishing object, The polishing composition comprises polishing particles, an accelerator, and a stabilizer, The accelerator comprises a cerium salt, The stabilizer is a compound represented by the following Chemical Formula 2 or Chemical Formula 3, The value of the polishing composition for semiconductor processes based on the following Formula 1 is less than 38%: [Chemical Formula 2] [Chemical Formula 3] wherein n is an integer of 0 to 4, R4is selected from the group consisting of methyl, ethyl, propyl, isobutyl, sec-butyl, pentyl, isopentyl, hexyl, a substituted or unsubstituted cycloalkyl group having a carbon number of 3 to 10, a substituted or unsubstituted alkenyl group having a carbon number of 2 to 10, and a substituted or unsubstituted alkynyl group having a carbon number of 2 to 10, R5is selected from the group consisting of hydrogen, a substituted or unsubstituted alkyl group having a carbon number of 1 to 10, a substituted or unsubstituted cycloalkyl group having a carbon number of 3 to 10, a substituted or unsubstituted alkenyl group having a carbon number of 2 to 10, and a substituted or unsubstituted alkynyl group having a carbon number of 2 to 10, [Formula 1] wherein the RR0 is a polishing rate determined using the polishing composition under the following polishing conditions, the RR f is a polishing rate determined after the polishing composition is stored at 45°C for 10 hours, cooled at 15°C to 25°C, and then under the following polishing conditions, For the polishing conditions, the temperature condition is 15°C to 25°C, the rotation speed of the polishing head is 87 rpm, the rotation speed of the platen is 93 rpm, the injection rate of the polishing composition is 90 ml / min, the polishing time is 60 seconds, the wafer is an amorphous carbon film wafer having a thickness of 2000 angstroms, a horizontal and vertical size of 4 cm x 4 cm, and polishing is performed using a small polishing machine, The RR0 and RR f The polishing rate is converted by measuring the thickness of the amorphous carbon film before and after polishing under the polishing conditions.

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