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

Abstract

A polishing composition for a semiconductor process according to one embodiment of the present invention includes polishing particles and a corrosion inhibitor. The corrosion inhibitor includes a first corrosion inhibitor as an aminoazole compound and a second corrosion inhibitor as a diazole compound. The polishing composition for a semiconductor process has a pH of 2 to 5. The polishing composition for a semiconductor process has a static etching rate with respect to a tungsten film of # imgabs0 # / min or less. By means of the polishing composition as described above, when a substrate including a tungsten film and a silicon oxide film is polished, a polishing rate of a predetermined level or more with respect to the silicon oxide film is exhibited while providing a polished surface with reduced defects.

Description

Technical Field

[0001] Examples relate to a polishing composition for semiconductor processing and a method for manufacturing a substrate using the composition. Background Art

[0002] As semiconductor devices become more sophisticated and denser, more sophisticated pattern forming technologies are being used, so the surface structure of semiconductor devices becomes more complex and the height difference between interlayer films becomes larger. When manufacturing semiconductor devices, a chemical mechanical polishing (CMP) process is used as a flattening technology for eliminating the height difference on a specific film formed on a substrate.

[0003] The CMP process is a process in which a substrate is pressurized, rotated, and the surface is polished while a slurry is provided on a polishing pad. Depending on the process steps, the object to be flattened is different, and the physical properties of the slurry applicable at this time are also different.

[0004] Polishing after forming metal wiring needs to minimize dishing and erosion while maintaining a sufficient polishing rate and polishing speed.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Korean Patent Publication No. 10-2015-0036422

[0008] Patent Document 2: Korean Patent Publication No. 10-2020-0104257 Summary of the invention

[0009] Technical issues

[0010] The purpose of the example is to provide a polishing composition for semiconductor process, which can achieve a polishing rate of silicon oxide film above a predetermined level when polishing a substrate surface including a tungsten film and a silicon oxide film, while preparing a polished surface with reduced defects.

[0011] Solutions to the problem

[0012] A polishing composition for a semiconductor process according to one embodiment of the present specification includes polishing particles and a corrosion inhibitor.

[0013] The corrosion inhibitor comprises a first corrosion inhibitor which is an aminoazole compound and a second corrosion inhibitor which is an oxadiazole compound.

[0014] The pH of the semiconductor process polishing composition is 2 to 5.

[0015] The static etching rate of the semiconductor process polishing composition on the tungsten film is / min or less.

[0016] The corrosion current density I of the polishing composition for semiconductor process on tungsten film corr Can be 60μA / cm 2 the following.

[0017] The corrosion potential E of the polishing composition for semiconductor process on tungsten film corr Can be above -30mV.

[0018] The semiconductor process polishing composition includes 0.07 wt. % to 3 wt. % of a corrosion inhibitor.

[0019] A ratio of the first corrosion inhibitor content (on a weight basis) to the second corrosion inhibitor content (on a weight basis) may be 0.6 to 2.0.

[0020] The corrosion inhibitor can inhibit corrosion of the tungsten film.

[0021] The polishing composition for semiconductor processes may further include a fluorine surfactant.

[0022] The semiconductor process polishing composition may include 10 ppm (by weight) to 500 ppm (by weight) of the fluorosurfactant.

[0023] The polishing composition for semiconductor process can have a polishing selectivity ratio of 5 or more for a silicon oxide film to a tungsten film.

[0024] A method for manufacturing a substrate according to another embodiment of the present specification includes a step of using the polishing composition for a semiconductor process as a slurry to polish a substrate.

[0025] Effects of the Invention

[0026] When polishing a substrate surface including a tungsten film and a silicon oxide film, by means of the polishing composition for semiconductor process of the example, a polishing rate for the silicon oxide film above a predetermined level can be exhibited while producing a polished surface with reduced defects. DETAILED DESCRIPTION

[0027] Hereinafter, the embodiments are described in detail so that those skilled in the art can easily implement the invention. However, the embodiments can be implemented in various forms and are not limited to the embodiments described herein.

[0028] The degree terms "about", "substantially" and the like as used in this specification are used to provide for inherent manufacturing and material tolerances in the mentioned meaning, when used on a numerical value or as a means close to that numerical value, to prevent unscrupulous infringers from improperly taking advantage of the disclosure that mentions exact or absolute values ​​to facilitate the understanding of the examples.

[0029] 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 constituent elements described in the Markush form expression, and means including one or more selected from the group consisting of the constituent elements.

[0030] Throughout the present specification, the description of "A and / or B" means "A, B, or, A and B".

[0031] Throughout the specification, unless otherwise specified, terms such as "first", "second" or "A", "B" and the like are used to distinguish the same term.

[0032] In the present specification, B being located on A means that B is located on A or B is located or can be located on A with other layers interposed therebetween, and should not be limitedly interpreted as B being located on A in contact with the surface of A.

[0033] In this specification, unless otherwise specified, a single form expression is interpreted as including the meaning of the single form or the plurality of forms explained in the context.

[0034] “A compound of the type A” includes “an aminoazole compound” and its derivatives. For example, an aminoazole compound refers to an aminoazole compound and a derivative of an aminoazole compound.

[0035] A substrate including a tungsten film and an insulating film is polished by applying a slurry having a high polishing selectivity ratio for the insulating film of the tungsten film. During the polishing process, defects caused by corrosion may be generated on the tungsten film. When a polishing composition having a low pH is applied, there is a tendency that the defects described above occur more frequently.

[0036] The inventors of the example applied a corrosion inhibitor comprising a first corrosion inhibitor and a second corrosion inhibitor to a polishing composition, and adjusted the static etching rate of the composition on a tungsten film, etc. Thus, the inventors experimentally confirmed that a polishing composition that can effectively inhibit the corrosion of a tungsten film even under low pH conditions and has excellent polishing characteristics for a silicon oxide film can be provided, and the example was completed.

[0037] Hereinafter, examples will be described in detail.

[0038] A polishing composition for a semiconductor process according to an example includes polishing particles and a corrosion inhibitor.

[0039] Physical properties of polishing compositions

[0040] In the example, the pH of the polishing composition can be controlled within a preset range, and the static etching rate of the tungsten film can be adjusted. Thus, while improving the polishing properties of the polishing composition on the silicon oxide film, the corrosion of the tungsten film caused by the acidic polishing composition can be stably suppressed.

[0041] The static etching rate of the tungsten film can be measured by the following method. The substrate on which the tungsten film is formed is immersed in the polishing composition for 10 minutes. Then, the difference in thickness of the tungsten film before and after the immersion is measured on the substrate, and the difference is divided by the immersion time to calculate the static etching rate.

[0042] The pH of the polishing composition is measured with a pH meter.

[0043] The pH of the polishing composition for semiconductor process is 2 to 5. The pH may be 2.5 to 5. The pH may be 3 or more. The pH may be 3.5 or more.

[0044] The static etching rate of the polishing composition on the tungsten film can be / minute or less. The static etching rate may be / minute or less. The static etching rate may be / minute or less. The static etching rate may be / minute or more.

[0045] In this case, as the polishing selectivity of the polishing composition to the silicon oxide film of the tungsten film is increased, the oxidation rate of the tungsten film exposed to the polishing composition is controlled, thereby suppressing excessive damage to the tungsten film during polishing.

[0046] In the example, the corrosion current density I of the tungsten film by the polishing composition can be controlled. corr , to help reduce the amount of corrosion of the tungsten film exposed to the polishing composition to below a predetermined level.

[0047] The corrosion current density I of the tungsten film of the polishing composition on the tungsten film corr Can be 60μA / cm 2 Below. corr Can be 40μA / cm 2 Below. corr Can be 30μA / cm 2 Below. corr Can be 20μA / cm 2 The following. corr Can be 1μA / cm 2In this case, the degree of damage to the tungsten wiring can be reduced during the polishing process.

[0048] Examples can be obtained by adjusting the corrosion potential E of the polishing composition. corr , to adjust the time when the tungsten film starts to corrode during the polishing process.

[0049] Corrosion potential E of polishing composition on tungsten film corr It can be above -30mV. corr The value can be above -25mV. corr The value can be above -20mV. corr The value can be above -15mV. corr The value may be +20 mV or less. In this case, the surface of the tungsten film in the surface to be polished can be polished flatly by polishing, and excessive erosion of the tungsten film by the polishing composition can be suppressed.

[0050] The corrosion current density I of the polishing composition on the tungsten film was measured by a constant potential instrument (Potentiostat) corr and corrosion potential E corr I corr and E corr The measurement conditions were set as follows.

[0051] -Reference Electrode: Saturated Calomel Electrode (SCE Saturated Calomel, sat'd KCl)

[0052] -Working Electrode Type: Solid Tungsten Electrode

[0053] -RED Speed: 0(volt)

[0054] -Working Electrode Area: 1cm 2

[0055] -Measured Open Circuit: 131.27mV (

[0056] Endpoint Properties

[0057] -Initial Potential: -1.5V (vs OC)

[0058] -Final Potential: 4V (vs Ref)

[0059] Scan Properties

[0060] -Step Height: 10mV

[0061] -Step Time: 1s

[0062] -Scan Rate: 10mV / s

[0063] -Total Points: 551

[0064] For example, I corr and E corr It can be measured using the VersaSTAT 4 model produced by AMETEK Scientific instruments.

[0065] The conductivity of the polishing composition for semiconductor process may be 20 μS / cm or more. The conductivity may be 40 μS / cm or more. The conductivity may be 70 μS / cm or more. The conductivity may be 400 μS / cm or less. The conductivity may be 300 μS / cm or less. The conductivity may be 200 μS / cm or less. In this case, it is possible to suppress excessive damage of the tungsten film due to chemical reaction during polishing, and at the same time, it is possible to help the polishing composition polish the polished surface at an excellent polishing rate.

[0066] The zeta potential of the polishing composition for semiconductor process may be +5 mV to +50 mV, the zeta potential may be above +10 mV, or below +40 mV.

[0067] The zeta potential of the polishing particles may be between +5 mV and +50 mV. The zeta potential may be above +10 mV. The zeta potential may be below +40 mV.

[0068] In this case, the polishing composition exhibits stable dispersibility, thereby suppressing the occurrence of defects on the polished surface caused by aggregation of polishing particles, etc. In addition, the polishing composition can exhibit excellent polishing characteristics for a silicon oxide film having a negative surface charge.

[0069] Composition of polishing composition

[0070] Polishing particles

[0071] The polishing composition can contain polishing particles.

[0072] The polishing particles may include metal oxide particles and / or silicon oxide particles. The polishing particles may include silica. The polishing particles may include colloidal silica.

[0073] The polishing particles may contain 70% or more of colloidal silica by weight. The polishing particles may contain 80% or more of colloidal silica by weight. The polishing particles may contain 90% or more of colloidal silica by weight. The polishing particles may be colloidal silica.

[0074] The polishing particles may have a positive charge on the surface. The polishing particles may be surface modified to have a positive charge on the surface. The polishing particles may be surface modified by a compound having an amine group. The polishing particles may be surface modified by an aminosilane.

[0075] For example, the aminosilane may be selected from 3-aminopropyltriethoxysilane, bis[(3-triethoxysilane)propyl]amine, 3-aminopropyltrimethoxysilane, bis[3-(trimethoxysilane)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilane)propyl]ethylenediamine, N-bis[3-(trimethoxysilane)propyl]-1,2- Any one of the group consisting of ethylenediamine, N-[3-(triethoxysilyl)propyl]ethylenediamine, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylaminomethyltriethoxysilane, diethylaminopropyltrimethoxysilane, diethylaminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]n-butylamine and combinations thereof.

[0076] The polishing composition for semiconductor process may contain 15 ppm (by weight) to 200 ppm (by weight) of aminosilane. The polishing composition for semiconductor process may contain 20 ppm (by weight) or more of aminosilane. The polishing composition for semiconductor process may contain 25 ppm (by weight) or more of aminosilane. The polishing composition for semiconductor process may contain 30 ppm (by weight) or more of aminosilane. The polishing composition for semiconductor process may contain 150 ppm (by weight) or less of aminosilane. The polishing composition for semiconductor process may contain 100 ppm (by weight) or less of aminosilane. The polishing composition for semiconductor process may contain 70 ppm (by weight) or less of aminosilane. The polishing composition for semiconductor process may contain 50 ppm (by weight) or less of aminosilane. In this case, the polishing composition has a more excellent 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, when residues of the surface modifier are generated, the residues can be effectively inhibited from being adsorbed onto the polished surface.

[0077] The polishing composition for semiconductor process may contain 1 wt % to 10 wt % of polishing particles. The polishing composition for semiconductor process may contain more than 2 wt % of polishing particles. The polishing composition for semiconductor process may contain less than 8 wt % of polishing particles. The polishing composition for semiconductor process may contain less than 5 wt % of polishing particles. In this case, the polishing composition has an excellent polishing rate on the polished surface and can stably suppress the aggregation of polishing particles.

[0078] The average particle size of the polishing particles may be 20 nm or more. The particle size may be 30 nm or more. The particle size may be 40 nm or more. The particle size may be 70 nm or less. The particle size may be 60 nm or less. The particle size may be 50 nm or less. In this case, the polishing composition may exhibit an excellent polishing rate on the polished surface, and may stably adjust the frequency of defects occurring on the polished surface.

[0079] The average particle size refers to the average particle size of primary particles of the polishing particles.

[0080] Corrosion Inhibitors

[0081] The corrosion inhibitor of the example includes a first corrosion inhibitor that is an aminoazole compound and a second corrosion inhibitor that is an oxadiazole compound.

[0082] When the polishing composition contains both the first corrosion inhibitor which is an aminoazole compound and the second corrosion inhibitor which is an oxadiazole compound, the corrosion resistance of the tungsten film to the acidic polishing composition can be more effectively improved. This is probably because when the first corrosion inhibitor and the second corrosion inhibitor are applied to the composition at the same time, the corrosion inhibitors more closely protect the surface of the tungsten film, thereby reducing the degree of exposure of the surface of the tungsten film to the polishing composition.

[0083] The first corrosion inhibitor is an azole compound containing one or more amine functional groups. Azoles are five-membered heterocyclic compounds containing one nitrogen and one or more non-carbon atoms in the ring.

[0084] The first corrosion inhibitor may be any one selected from the group consisting of aminoimidazole, aminopyrazole, aminotriazole, aminotetrazole, aminooxazole, aminoisoxazole, aminooxadiazole, aminothiazole, aminoisothiazole, aminothiadiazole, and combinations thereof.

[0085] The second corrosion inhibitor is a diazole compound. Diazole refers to a five-membered cyclic compound containing three carbon atoms and two nitrogen atoms in the ring. The second corrosion inhibitor is different from the first corrosion inhibitor in that the second corrosion inhibitor does not contain an amine group.

[0086] The second corrosion inhibitor may be any one selected from the group consisting of imidazole, pyrazole, and a combination thereof.

[0087] The polishing composition for semiconductor process may contain 0.07 wt % to 3 wt % of corrosion inhibitor. The polishing composition for semiconductor process may contain 0.09 wt % or more of corrosion inhibitor. The polishing composition for semiconductor process may contain 2 wt % or less of corrosion inhibitor. The polishing composition for semiconductor process may contain 1 wt % or less of corrosion inhibitor. In this case, the degree of damage to the tungsten film caused by the chemical reaction between the polishing composition and the tungsten film during the polishing process can be effectively reduced.

[0088] In the polishing composition, the ratio of the first corrosion inhibitor content (based on weight) to the second corrosion inhibitor content (based on weight) may be 0.6 to 2.0. The ratio may be 0.8 or more. The ratio may be 1.6 or less. In this case, oxidation of tungsten during polishing can be further effectively suppressed.

[0089] The polishing composition may include 0.01 wt. % to 0.2 wt. % of the first corrosion inhibitor. The polishing composition may include 0.02 wt. % or more of the first corrosion inhibitor. The polishing composition may include 0.04 wt. % or more of the first corrosion inhibitor. The polishing composition may include 0.1 wt. % or less of the first corrosion inhibitor.

[0090] The polishing composition may include 0.01 wt. % to 0.2 wt. % of the second corrosion inhibitor. The polishing composition may include 0.02 wt. % or more of the second corrosion inhibitor. The polishing composition may include 0.04 wt. % or more of the second corrosion inhibitor. The polishing composition may include 0.1 wt. % or less of the second corrosion inhibitor.

[0091] In this case, the degradation of the tungsten wiring due to corrosion can be further stably suppressed.

[0092] Fluorinated surfactants

[0093] In an example, a fluorine surfactant can be applied to the polishing composition. The surfactant adheres to the surface of organic particles generated during the polishing process and can inhibit the particles from being adsorbed on the surface of the tungsten film or the silicon oxide film. In addition, the surfactant can adhere to the surface of the silicon oxide film to prevent the polishing particles from being adsorbed on the surface of the silicon oxide film or from forming scratches on the surface.

[0094] The fluorine surfactant may be a fluoroalkyl epoxyalkyl compound. The fluorine surfactant may be a compound represented by the following Chemical Formula 1.

[0095]

Chemical formula 1

[0096] R f -(R en -O) n -H

[0097] In the chemical formula 1, the R f is a fluoroalkyl group having 3 to 10 carbon atoms, wherein R en is an alkylene group having 2 or 3 carbon atoms, and n is an integer of 2 to 15.

[0098] In the chemical formula 1, R f The perfluoroalkyl group may be a group having 3 to 10 carbon atoms.

[0099] The fluorine surfactant may be a polymer surfactant. The weight average molecular weight of the fluorine 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.

[0100] The fluorine surfactant having the above-mentioned characteristics has a main chain length adjusted so that organic particles can be effectively discharged. In addition, the dispersibility of the polishing composition can be prevented from being excessively deteriorated due to the surfactant.

[0101] The weight average molecular weight of the polymer surfactant is measured by gel permeation chromatography (GPC).

[0102] In the example, the content of the fluorinated surfactant can be adjusted within a preset range, thereby preventing organic particles from adhering to the polished surface after polishing, and preventing excessive foam from being generated in the polishing composition during the polishing process to prevent process performance from being reduced.

[0103] The polishing composition for semiconductor process may contain more than 10 ppm (based on weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 20 ppm (based on weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 50 ppm (based on weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 100 ppm (based on weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 150 ppm (based on weight) of fluorine surfactant. The polishing composition for semiconductor process may contain less than 500 ppm (based on weight) of fluorine surfactant. The polishing composition for semiconductor process may contain less than 450 ppm (based on weight) of fluorine surfactant. In this case, the hydrophilicity of the polishing pad residue can be effectively improved while suppressing the generation of excessive foam during the polishing process.

[0104] Other additives

[0105] The semiconductor process polishing composition may further include other additives. The additives are not limited as long as they are conventionally used additives in the CMP field. For example, the additives may be at least one of an oxidant, an acid component, a pH adjuster, a chelating agent, a dispersant, a polishing rate enhancer, a polishing regulator, a polishing pad protector, and a preservative.

[0106] The polishing composition for semiconductor processing may further include an oxidizing agent. The role of the oxidizing agent is to oxidize metals such as tungsten, create an environment that makes it easier to planarize the substrate surface, and increase the polishing rate and etching rate.

[0107] 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.

[0108] The polishing composition for semiconductor process may contain 0.01 wt % to 5 wt % of an oxidizing agent. In this case, the composition may exhibit excellent polishing characteristics for metals and may suppress the formation of an oxide film on the metal to be polished during polishing.

[0109] The polishing composition for semiconductor processing further comprises an acid component. The acid component can be, for example, at least one selected from the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, bromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, adipic acid, acetic acid, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid and salts thereof.

[0110] The polishing composition for semiconductor processing may contain an acid component and a pH adjuster. The pH adjuster may be any one selected from the group consisting of ammonia, aminopropanol, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate, and combinations thereof.

[0111] The polishing composition for semiconductor processing may contain a chelating agent. The chelating agent can prevent the adsorption of polishing metal particles on the polished surface.

[0112] The chelating agent may contain two or more carboxyl groups or alcohol groups in the molecule. As the chelating agent, two or more chelating agents containing two or more carboxyl groups or alcohol groups in the molecule may be used. Specifically, the chelating agent may include any one selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), glycine, carboxylic acids, and combinations thereof. The carboxylic acids refer to compounds containing at least one or more carboxyl groups in the molecule.

[0113] The polishing composition for semiconductor processing may further comprise a dispersant.

[0114] The dispersant can prevent aggregation of polishing particles in the polishing composition and make them uniformly dispersed. Cationic dispersants can increase the zeta potential of the polishing composition to a positive (+) value, and anionic dispersants can reduce the zeta potential of the polishing composition to a negative (-) value.

[0115] The dispersant may include anionic low molecular weight, cationic high molecular weight, organic acid, and the like.

[0116] The anionic low molecular weight dispersant may be one or more selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, and combinations thereof.

[0117] 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, dioctadecyldimethylammonium chloride, polyarylamines and combinations thereof.

[0118] 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 combinations thereof.

[0119] The polishing rate enhancer is an additive used to increase the polishing rate of the substrate or wiring to be polished, and can be one or more selected from potassium nitrate, ferric nitrate, ammonium hydroxide, citric acid, acetic acid and combinations thereof.

[0120] 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.

[0121] The polishing composition for semiconductor process may contain a solvent, which may be water, and specifically, ultrapure water.

[0122] Polishing properties of polishing compositions

[0123] The polishing rate of the semiconductor process polishing composition for silicon oxide film can be / minute or more. The polishing rate may be / minute or more. The polishing rate may be 1100 / minute or more. The polishing rate may be / minute or less. The polishing rate may be / minute or less. The polishing rate may be / min or less.

[0124] The polishing rate of the semiconductor process polishing composition for tungsten film can be / minute or more. The polishing rate may be / minute or more. The polishing rate may be / minute or less. The polishing rate may be / minute or less. The polishing rate may be / min or less.

[0125] The polishing selectivity of the polishing composition for semiconductor process to the silicon oxide film of the tungsten film may be 5 or more. The polishing selectivity may be 6 or more. The polishing selectivity may be 7 or more. The polishing selectivity may be 20 or less.

[0126] 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.

[0127] The Ra value of the tungsten film measured after polishing with the semiconductor process polishing composition for 30 seconds can be 3 nm or less. The Ra value can be 2 nm or less. The Ra value can be 1.5 nm or less. The Ra value can be 1 nm or less. The polishing composition having the above characteristics can provide a tungsten film that reduces the degree of damage due to corrosion when polishing is applied.

[0128] The Ra value is measured according to ISO 4287 using an atomic force microscope (AFM).

[0129] Polishing of each film was performed 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 the SR-300 model of SK ENPULSE Co., Ltd. of Korea.

[0130] When the polishing rate of each thin film is measured, the polishing machine may exemplarily use the AP-300 model of CTS Corporation of Korea.

[0131] Method for manufacturing substrate

[0132] The method for manufacturing a substrate of the example includes a process of polishing a substrate using the polishing composition for semiconductor processes as a slurry.

[0133] The substrate may include at least one of an insulating film, a metal wiring and a barrier layer on the upper surface. 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.

[0134] Specifically, when the substrate is polished, the substrate to be polished is brought into contact with the semiconductor process polishing composition supplied from a nozzle on the polishing pad, and the polishing head fixing the substrate rotates, and the top plate attached with the polishing pad also rotates.

[0135] If necessary, the process of polishing the substrate may further include a process of adjusting the surface of the polishing pad before polishing.

[0136] The polishing composition for semiconductor processing can penetrate toward the substrate and polish the wafer in contact with the polishing pad at the same time.

[0137] During 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.

[0138] The process of polishing the substrate may be carried out for 50 seconds to 10 minutes, but this may be varied depending on the desired polishing degree.

[0139] The description of the polishing composition for semiconductor process overlaps with the above description and is therefore omitted.

[0140] The method for manufacturing a substrate may further include a cleaning process of cleaning the polished substrate.

[0141] The cleaning process may be performed by using pure water and inactive gas to clean the polished substrate.

[0142] The following embodiments are only examples for helping to understand the present invention, and the scope of the present invention is not limited thereto.

[0143] Preparation Example: Preparation of polishing composition

[0144] Example 1: In ultrapure water as a solvent, 3 wt% of colloidal silica surface-modified with 38 ppm (by weight) of (3-aminopropyl)triethoxysilane as polishing particles, 0.05 wt% of aminotetrazole as a first corrosion inhibitor, 0.05 wt% of imidazole as a second corrosion inhibitor, 20 ppm (by weight) of FS 3100 produced by Capstone, USA as a fluorosurfactant, 1 wt% of sorbitol as a pad protective agent, and 2 wt% of sucrose were added and mixed to prepare a polishing composition of 100 wt% in total.

[0145] Comparative Example 1: A polishing composition of 100 wt% was prepared under the same conditions as in Example 1, except that 0.05 wt% of aminotetrazole was used as a corrosion inhibitor, 2 wt% of sorbitol was used as a pad protectant, and the average particle size of the polishing particles, pH, conductivity, and zeta potential of the polishing composition were as shown in Table 2.

[0146] Comparative Example 2: No corrosion inhibitor was used, 2 wt% sorbitol was used as a pad protectant, and the average particle size of the polishing particles, pH, conductivity, and zeta potential of the polishing composition were applied as shown in Table 2. In addition, a polishing composition of 100 wt% was prepared under the same conditions as in Example 1.

[0147] The content of each component in the polishing composition of each example and comparative example and the average particle size (primary particle size) of the polishing particles are recorded in Table 1 below, and the pH, conductivity, and zeta potential are recorded in Table 2 below.

[0148] Evaluation Example: Measurement of Static Etching Rate

[0149] The substrate with the tungsten film formed thereon was immersed in the polishing composition of each example and comparative example for 10 minutes. Then, the difference in thickness of the tungsten film before and after the immersion was measured on the substrate, and the difference was divided by the immersion time to calculate the static etching rate.

[0150] The static etching rates of the various examples and comparative examples are shown in Table 2 below.

[0151] Evaluation example: Measurement of corrosion-related characteristics

[0152] The corrosion current density I of the polishing composition of each embodiment and comparative example on the tungsten film was measured using a potentiostat (VersaSTAT 4) of AMETEK Scientific Instruments, Inc. corr and corrosion potential E corr The measurement conditions were set as follows.

[0153] -Reference Electrode: Saturated Calomel Electrode (SCE Saturated Calomel, sat'd KCl)

[0154] -Working Electrode Type: Solid Tungsten Electrode

[0155] -RED Speed: 0(volt)

[0156] -Working Electrode Area: 1cm 2

[0157] -Measured Open Circuit: 131.27mV

[0158] Endpoint Properties

[0159] -Initial Potential: -1.5V (vs OC)

[0160] -Final Potential: 4V (vs Ref)

[0161] Scan Properties

[0162] -Step Height: 10mV

[0163] -Step Time: 1s

[0164] -Scan Rate: 10mV / s

[0165] -Total Points: 551

[0166] The measured values ​​and calculated values ​​of each Example and Comparative Example are shown in Table 2 below.

[0167] Evaluation example: Measurement of polishing characteristics and detection of defects

[0168] The upper surface of a wafer having a diameter of 300 mm was polished using the polishing composition using an AP-300 polishing machine produced by CTS Corporation of Korea.

[0169] Polishing was performed 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.

[0170] The wafer includes a tungsten pattern with a pattern density of 50% and a silicon oxide film.

[0171] After polishing was completed, the polishing rate of each film of the polishing composition and the polishing selectivity of the silicon oxide film to the tungsten film were calculated by measuring the thickness difference between the silicon oxide film and the tungsten film before and after polishing.

[0172] Next, the number of defects detected in the silicon oxide film on the surface of the wafer was measured using Tenkor's XP+ defect measurement equipment.

[0173] Furthermore, according to ISO 4287, the Ra value of the tungsten film on the surface of the substrate after polishing was measured using an atomic force microscope (AFM).

[0174] The measured values ​​of each example and comparative example are shown in Table 3 below.

[0175] Evaluation Example: Measurement of Bubble Generation Amount

[0176] 3 L of the polishing composition of each example and comparative example was added to a glass reactor of 5 L. The added polishing composition was stirred at 1000 RPM for 30 minutes at 25° C. using a four-blade blade with a total length of 10 cm. After 10 minutes had passed from the time when the stirring was completed, 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.

[0177] The bubble volume values ​​calculated for each embodiment and comparative example are shown in Table 3 below.

[0178] Table 1

[0179]

[0180] Table 2

[0181]

[0182] Table 3

[0183]

[0184] As shown in Table 2, Example 1 shows lower corrosion potential value and lower corrosion current density than Comparative Examples 1 and 2. That is, compared with Comparative Examples 1 and 2, Example 1 has a faster corrosion start time but a smaller corrosion amount.

[0185] For the static etching rate, Example 1 shows / min or less, whereas Comparative Example 2 shows / min or more.

[0186] This means that, in the case of Example 1 in which two corrosion inhibitors are applied, when the polishing composition comes into contact with the tungsten film, the corrosion progresses much slower than that of the polishing composition of Comparative Example 2.

[0187] As for the Ra value of the tungsten film, Example 1 shows a lower value than that of the comparative example. This means that when polishing with the composition of Example 1, the tungsten film is damaged by corrosion to a lesser extent than that of the comparative example.

[0188] As for the bubble volume, both the Examples and Comparative Examples showed a value of 20 mL, which means that even if a surfactant is used in the polishing composition, excessive foam is not generated during the polishing process.

[0189] The preferred embodiments are described in detail above, but the scope of protection of the invention claimed by the present invention is not limited thereto. Various deformations and improvements made by ordinary technicians in the technical field to which the present invention belongs using the basic concepts of the examples defined in the attached scope of protection of the invention also fall within the scope of protection of the invention claimed by the present invention.

Claims

1. A polishing composition for semiconductor processing, wherein: Include: Polishing particles, and Corrosion inhibitors; The corrosion inhibitor comprises: As the first corrosion inhibitor of aminoazole compounds, and As a secondary corrosion inhibitor of diazole compounds; The pH of the semiconductor process polishing composition is 2 to 5, The static etching rate of the semiconductor process polishing composition on the tungsten film is / min or less.

2. The semiconductor process polishing composition according to claim 1, wherein The corrosion current density I of the polishing composition for semiconductor process on tungsten film corr 60μA / cm 2 the following.

3. The semiconductor process polishing composition according to claim 1, wherein The corrosion potential E of the polishing composition for semiconductor process on tungsten film corr Above -30mV.

4. The semiconductor process polishing composition according to claim 1, wherein The polishing composition for semiconductor process includes 0.07 wt % to 3 wt % of the corrosion inhibitor.

5. The semiconductor process polishing composition according to claim 1, wherein A ratio of the content of the first corrosion inhibitor on a weight basis to the content of the second corrosion inhibitor on a weight basis is 0.6 to 2.

0.

6. The semiconductor process polishing composition according to claim 1, wherein The corrosion inhibitor inhibits corrosion of the tungsten film.

7. The semiconductor process polishing composition according to claim 1, wherein The semiconductor process polishing composition further comprises 10 ppm to 500 ppm by weight of a fluorine surfactant.

8. The semiconductor process polishing composition according to claim 1, wherein The polishing composition for semiconductor process has a polishing selectivity ratio of tungsten film to silicon oxide film of 5 or more.

9. A method for manufacturing a substrate, wherein: The method comprises the step of using the polishing composition for semiconductor process according to claim 1 as a slurry to polish a substrate.

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