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

Abstract

To provide a polishing composition for semiconductor process and a method for manufacturing a substrate using the composition, which, when polishing the substrate containing a tungsten film and a silicon oxide film, exhibits a polishing speed above a certain level for the silicon oxide film and realizes a surface to be polished with reduced defects.SOLUTION: In a polishing composition for semiconductor processes containing abrasive particles and a corrosion inhibitor, the corrosion inhibitor includes a first corrosion inhibitor that is an aminoazole compound and a second corrosion inhibitor that is a diazole compound. The pH of the polishing compositions for semiconductor processes is 2-5. The static etching rate of the polishing composition for semiconductor processes for tungsten film is less than 6Å / min.SELECTED DRAWING: None

Description

Technical Field

[0001] Embodiments relate to a polishing composition for semiconductor processes, a method for manufacturing a substrate using the same, and the like.

Background Art

[0002] As semiconductor elements are further miniaturized and densified, even finer patterning technologies are being used, which has made the surface structure of semiconductor elements more complex and the step height of the interlayer film even larger. In manufacturing semiconductor elements, a chemical mechanical polishing (hereinafter referred to as "CMP") process is used as a planarization technology for removing steps in a specific film formed on a substrate.

[0003] In the CMP process, while slurry is supplied to a polishing pad, the substrate is pressurized and rotated to polish the surface. Depending on the stage of the process, the object to be planarized changes, and there are also differences in the physical properties of the slurry applied at this time.

[0004] After metal wiring is formed, polishing is required to maintain sufficient polishing rate and polishing speed while minimizing dishing or erosion.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] The objective of the embodiment is to provide a polishing composition for semiconductor processes that can exhibit a polishing rate of a certain level or higher with respect to the silicon oxide film and provide a polished surface with reduced defects when polishing the substrate surface including the tungsten film and the silicon oxide film.

Means for Solving the Problem

[0007] The polishing composition for semiconductor processes according to an embodiment of the present specification includes polishing particles and a corrosion inhibitor.

[0008] The corrosion inhibitor includes a first corrosion inhibitor that is an aminoazole-based compound and a second corrosion inhibitor that is a diazole-based compound.

[0009] The pH of the polishing composition for semiconductor processes is 2 to 5.

[0010] The static etching rate of the polishing composition for semiconductor processes with respect to the tungsten film is 6 Å / min or less.

[0011] I, which is the corrosion current density of the polishing composition for semiconductor processes with respect to the tungsten film corr may be 60 μA / cm 2 or less.

[0012] E, which is the corrosion potential of the polishing composition for semiconductor processes with respect to the tungsten film corr may be -30 mV or more.

[0013] The polishing composition for semiconductor processes may contain 0.07% to 3% by weight of a corrosion inhibitor.

[0014] The ratio of the content (by weight) of the second corrosion inhibitor to the content (by weight) of the first corrosion inhibitor may be 0.6 to 2.0.

[0015] The corrosion inhibitor can suppress the corrosion of the tungsten film.

[0016] The polishing composition for semiconductor processes may further contain a fluorosurfactant.

[0017] The polishing composition for semiconductor processes may contain the fluorosurfactant in an amount of 10 ppm (by weight) to 500 ppm (by weight).

[0018] The polishing selectivity of the silicon oxide film with respect to the tungsten film of the polishing composition for semiconductor processes may be 5 or more.

[0019] The method for manufacturing a substrate according to another embodiment of this specification includes a process of applying the polishing composition for semiconductor processes as a slurry to polish the substrate.

Advantages of the Invention

[0020] When polishing the surface of a substrate including a tungsten film and a silicon oxide film, the polishing composition for semiconductor processes in the embodiment can exhibit a polishing rate of a certain level or more with respect to the silicon oxide film and provide a polished surface with reduced defects.

Best Mode for Carrying Out the Invention

[0021] Hereinafter, the embodiments will be described in detail so that those having ordinary knowledge in the technical field to which the embodiments belong can easily implement them. However, the embodiments can be implemented in various different forms and are not limited to the embodiments described here.

[0022] Terms such as "about" and "substantially" used in this specification are used in a meaning that is the same as or close to that numerical value when manufacturing and material tolerances inherent to the mentioned meaning are presented, and are used to prevent unscrupulous infringers from improperly using the disclosed content where exact or absolute numerical values are mentioned to assist in the understanding of the embodiments.

[0023] Throughout this specification, the term "these combinations" included in the Markush-form expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-form expression, and means including one or more selected from the group consisting of the said components.

[0024] Throughout this specification, the description of "A and / or B" means "A, B, or A and B".

[0025] Throughout this specification, terms such as "first", "second" or "A", "B" are used to distinguish the same terms from each other unless otherwise specified.

[0026] In this specification, the meaning that B is located on A means that B can be located on A, or B can be located on A while another layer is located between them, and is not construed as being limited to B being located in contact with the surface of A.

[0027] In this specification, a singular expression is construed to include a singular or plural meaning as construed in the context unless otherwise specified.

[0028] "~-based compound" includes "~ compound" and its derivatives. Exemplarily, an aminoazole-based compound means an aminoazole compound and derivatives of the aminoazole compound.

[0029] A slurry with a high polishing selectivity of the insulating film with respect to the tungsten film can be applied to polish a substrate including the tungsten film and the insulating film. During the polishing process, defects due to corrosion may occur in the tungsten film. Such defects tend to occur more frequently when applying a polishing composition with a low pH.

[0030] The inventors of the embodiments applied a corrosion inhibitor containing a first corrosion inhibitor and a second corrosion inhibitor to the polishing composition to adjust the static etching rate of the tungsten film of the composition, etc. Through this, the inventors experimentally confirmed that they can effectively suppress the corrosion of the tungsten film even under low pH conditions and provide a polishing composition having excellent polishing characteristics for a silicon oxide film, and completed the embodiments.

[0031] Hereinafter, the embodiments will be specifically described.

[0032] The polishing composition for semiconductor processes according to the embodiments includes polishing particles and a corrosion inhibitor.

[0033] Physical properties of the polishing composition The embodiments can control the pH of the polishing composition within a preset range and adjust the static etching rate of the tungsten film. Through this, while improving the polishing characteristics of the polishing composition for the silicon oxide film, it is possible to stably suppress the corrosion of the tungsten film by the acidic polishing composition.

[0034] The static etching rate for the tungsten film is measured by the following method. A substrate on which a tungsten film is formed is immersed in the polishing composition for 10 minutes. Then, the difference value of the thickness of the tungsten film on the substrate before and after immersion is measured, and the static etching rate is calculated by dividing the difference value by the immersion time.

[0035] The pH of the polishing composition is measured with a pH meter.

[0036] The pH of the polishing composition for semiconductor processes 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.

[0037] The static etching rate of the polishing composition with respect to the tungsten film may be 6 Å / min or less. The static etching rate may be 5 Å / min or less. The static etching rate may be 4 Å / min or less. The static etching rate may be 0.1 Å / min or more.

[0038] In such a case, the polishing selectivity of the silicon oxide film with respect to the tungsten film of the polishing composition is improved, and the oxidation rate of the tungsten film exposed to the polishing composition is controlled, suppressing excessive damage to the tungsten film during the polishing process.

[0039] An embodiment is to control I corr which is the corrosion current density of the polishing composition with respect to the tungsten film, which can help reduce the corrosion amount of the tungsten film exposed to the polishing composition to a certain level or less.

[0040] I of the polishing composition with respect to the tungsten film corr may be 60 μA / cm 2 or less. The I corr may be 40 μA / cm 2 or less. The I corr may be 30 μA / cm 2 or less. The I corr may be 20 μA / cm 2 or less. The I corr may be 1 μA / cm 2 or more. In such a case, the degree of damage to the tungsten wiring during the polishing process can be reduced.

[0041] An embodiment is to adjust the corrosion potential E corr of the polishing composition to adjust the time point when the tungsten film starts to corrode during the polishing process.

[0042] E which is the corrosion potential of the polishing composition with respect to the tungsten film corr may be -30 mV or more. The E corr value may be -25 mV or more. The E corrThe value may be -20 mV or more. The E corr The value may be -15 mV or more. The E corr The value may be +20 mV or less. In such a case, the surface of the tungsten film in the surface to be polished can be polished flat through polishing, and excessive erosion of the tungsten film by the polishing composition can be suppressed.

[0043] The corrosion current density I of the polishing composition with respect to the tungsten film corr and the corrosion potential E corr are measured with a potentiostat. I corr and E corr The measurement conditions are set as follows. -Reference Electrode:SCE Saturated Calomel(sat'd KCl) -Working Electrode Type:Solid Tungsten Electrode -RED Speed:0volt -Working Electrode Area:1cm 2 -Measured Open Circuit:131.27mV Endpoint Properties -Initial Potential:-1.5V(vs OC) -Final Potential:4V(vs Ref) Scan Properties -Step Height:10mV -Step Time:1s -Scan Rate:10mV / s -Total Points:551

[0044] Exemplarily, I corr and E corr can be measured with the versaSTAT4 model of AMETEK Scientific instruments.

[0045] The electrical conductivity of the polishing composition for semiconductor processes may be 20 μS / cm or more. The electrical conductivity may be 40 μS / cm or more. The electrical conductivity may be 70 μS / cm or more. The electrical conductivity may be 400 μS / cm or less. The electrical conductivity may be 300 μS / cm or less. The electrical conductivity may be 200 μS / cm or less. In such cases, it can help to suppress the excessive damage of the tungsten film by chemical reaction during the polishing process and enable the polishing composition to polish the surface to be polished at an excellent polishing rate.

[0046] The zeta potential of the polishing composition for semiconductor processes can be +5 mV to +50 mV. The zeta potential may be +10 mV or more. The zeta potential may be +40 mV or less.

[0047] The zeta potential of the polishing particles can be +5 mV to +50 mV. The zeta potential may be +10 mV or more. The zeta potential may be +40 mV or less.

[0048] In such cases, the polishing composition exhibits stable dispersibility and can suppress the generation of defects on the surface to be polished due to aggregation of polishing particles or the like. Further, the polishing composition can exhibit excellent polishing characteristics with respect to a silicon oxide film having a surface negative charge.

[0049] Composition of the polishing composition Abrasive particles The polishing composition can contain polishing particles.

[0050] The polishing particles can contain metal oxide particles and / or silicon oxide particles. The polishing particles can contain silica. The polishing particles can contain colloidal silica.

[0051] The abrasive particles may contain 70% by weight or more of colloidal silica. The abrasive particles may contain 80% by weight or more of colloidal silica. The abrasive particles may contain 90% by weight or more of colloidal silica. The abrasive particles may be colloidal silica.

[0052] The abrasive particles can have a positively charged surface. The abrasive particles may be surface-modified so as to have a positively charged surface. The abrasive particles may be surface-modified with a compound having an amine group. The abrasive particles may be surface-modified with an aminosilane.

[0053] Exemplary aminosilanes include any one selected from the group consisting of 3-aminopropyltriethoxysilane, bis[(3-triethoxysilyl)propyl]amine, 3-aminopropyltrimethoxysilane, bis[(3-trimethoxysilyl)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine, N-bis[3-(trimethoxysilyl)propyl]-1,2-ethylenediamine, N-[3-(triethoxysilyl)propyl]ethylenediamine, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylaminomethyltriethoxysilane, diethylaminopropyltrimethoxysilane, diethylaminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]butylamine, and combinations thereof.

[0054] The polishing composition for semiconductor processes can contain 15 ppm (by weight) to 200 ppm (by weight) of aminosilane. The polishing composition for semiconductor processes may contain 20 ppm (by weight) or more of aminosilane. The polishing composition for semiconductor processes may contain 25 ppm (by weight) or more of aminosilane. The polishing composition for semiconductor processes may contain 30 ppm (by weight) or more of aminosilane. The polishing composition for semiconductor processes may contain 150 ppm (by weight) or less of aminosilane. The polishing composition for semiconductor processes may contain 100 ppm (by weight) or less of aminosilane. The polishing composition for semiconductor processes may contain 70 ppm (by weight) or less of aminosilane. The polishing composition for semiconductor processes may contain 50 ppm (by weight) or less of aminosilane. In such cases, the polishing composition has a better polishing rate for the silicon oxide film, can polish the surface of the substrate to be polished more smoothly, and can exhibit improved dispersibility. At the same time, residues of the surface modifier are generated, and adsorption of the residues to the surface to be polished can be effectively suppressed.

[0055] The polishing composition for semiconductor processes can contain 1 wt% to 10 wt% of polishing particles. The polishing composition for semiconductor processes may contain 2 wt% or more of polishing particles. The polishing composition for semiconductor processes may contain 8 wt% or less of polishing particles. The polishing composition for semiconductor processes may contain 5 wt% or less of polishing particles. In such cases, the polishing composition has an excellent polishing rate for the surface to be polished and can stably suppress aggregation of the polishing particles.

[0056] The average particle size of the polishing particles may be 20 nm or more. The average particle size may be 30 nm or more. The average particle size may be 40 nm or more. The average particle size may be 70 nm or less. The average particle size may be 60 nm or less. The average particle size may be 50 nm or less. In such cases, the polishing composition exhibits an excellent polishing rate for the surface to be polished and can stably adjust the frequency of occurrence of defects on the surface to be polished.

[0057] The average particle size means the average particle size of the primary particles of the polishing particles.

[0058] Corrosion inhibitor The corrosion inhibitor of the embodiment includes a first corrosion inhibitor which is an aminoazole compound and a second corrosion inhibitor which is a diazole compound.

[0059] When both the first corrosion inhibitor which is an aminoazole compound and the second corrosion inhibitor which is a diazole compound are included in the polishing composition, the corrosion resistance of the tungsten film against the acidic polishing composition can be more effectively improved. This is considered to be because when the first corrosion inhibitor and the second corrosion inhibitor are both applied to the composition, the corrosion inhibitor protects the surface of the tungsten film more densely, and the degree to which the surface of the tungsten film is exposed in the polishing composition is reduced.

[0060] The first corrosion inhibitor is an azole compound containing one or more amine groups as functional groups. An azole is a 5-membered cyclic hetero compound containing one nitrogen and one or more non-carbon atoms in the ring.

[0061] 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.

[0062] The second corrosion inhibitor is a diazole compound. A diazole is a 5-membered cyclic compound containing three carbons and two nitrogens in the ring. The second corrosion inhibitor is distinguished from the first corrosion inhibitor in that it does not contain an amine group.

[0063] The second corrosion inhibitor may be any one selected from the group consisting of imidazole, pyrazole, and combinations thereof.

[0064] The polishing composition for semiconductor processes can contain 0.07 wt% to 3 wt% of a corrosion inhibitor. The polishing composition for semiconductor processes may contain 0.09 wt% or more of a corrosion inhibitor. The polishing composition for semiconductor processes may contain 2 wt% or less of a corrosion inhibitor. The polishing composition for semiconductor processes may contain 1 wt% or less of a corrosion inhibitor. In such cases, the degree of damage to the tungsten film due to the chemical reaction between the polishing composition and the tungsten film during the polishing process can be effectively reduced.

[0065] In the polishing composition, the ratio of the content (by weight) of the second corrosion inhibitor to the content (by weight) of the first corrosion inhibitor can be 0.6 to 2.0. The ratio may be 0.8 or more. The ratio may be 1.6 or less. In such cases, the oxidation of tungsten during the polishing process can be more effectively suppressed.

[0066] The polishing composition can contain 0.01 wt% to 0.2 wt% of the first corrosion inhibitor. The polishing composition may contain 0.02 wt% or more of the first corrosion inhibitor. The polishing composition may contain 0.04 wt% or more of the first corrosion inhibitor. The polishing composition may contain 0.1 wt% or less of the first corrosion inhibitor.

[0067] The polishing composition can contain 0.01 wt% to 0.2 wt% of the second corrosion inhibitor. The polishing composition may contain 0.02 wt% or more of the second corrosion inhibitor. The polishing composition may contain 0.04 wt% or more of the second corrosion inhibitor. The polishing composition may contain 0.1 wt% or less of the second corrosion inhibitor.

[0068] In such cases, the deterioration of the tungsten wiring due to corrosion can be more stably suppressed.

[0069] Fluorine-based surfactant Embodiments can apply a fluorosurfactant to the polishing composition. By adhering to the surface of organic particles generated during the polishing process, the surfactant can suppress the adsorption of the particles to the surface of a tungsten film or a silicon oxide film. Further, by adhering to the surface of the silicon oxide film, the surfactant can prevent the polishing particles from adsorbing to the surface of the silicon oxide film or forming scratches on the surface.

[0070] The fluorosurfactant may be a fluoroalkyl alkylene oxide-based compound. The fluorosurfactant may be a compound represented by the following Chemical Formula 1.

[0071] [Chemical Formula 1] R f -(R en -O) n -H

[0072] In Chemical Formula 1, the R f is a fluoroalkyl group having 3 to 10 carbon atoms, the R en is an alkylene group having 2 or 3 carbon atoms, and n is an integer of 2 to 15.

[0073] In Chemical Formula 1, R f may be a perfluoroalkyl group having 3 to 10 carbon atoms.

[0074] The fluorosurfactant may be a polymeric surfactant. The fluorosurfactant may have a weight average molecular weight of 150 g / mol to 3,000 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 2,500 g / mol or less. The weight average molecular weight may be 2,000 g / mol or less. The weight average molecular weight may be 1,500 g / mol or less.

[0075] The fluorosurfactant having the characteristics as described above comes to have a regulated main chain length and can efficiently discharge organic particles. Further, it is possible to prevent the dispersibility of the polishing composition from being excessively deteriorated by the surfactant.

[0076] The weight average molecular weight of the polymeric surfactant is measured through GPC (Gel Permeation Chromatography).

[0077] In the embodiment, the content of the fluorosurfactant can be adjusted within a preset range. Through this, it is possible to suppress the adhesion of organic particles to the surface to be polished after polishing, and to prevent the excessive generation of bubbles in the polishing composition during the polishing process, thereby preventing the deterioration of processability.

[0078] The polishing composition for semiconductor processes may contain 10 ppm (by weight) or more of a fluorosurfactant. The polishing composition for semiconductor processes may contain 20 ppm (by weight) or more of a fluorosurfactant. The polishing composition for semiconductor processes may contain 50 ppm (by weight) or more of a fluorosurfactant. The polishing composition for semiconductor processes may contain 100 ppm (by weight) or more of a fluorosurfactant. The polishing composition for semiconductor processes may contain 150 ppm (by weight) or more of a fluorosurfactant. The polishing composition for semiconductor processes may contain 500 ppm (by weight) or less of a fluorosurfactant. The polishing composition for semiconductor processes may contain 450 ppm (by weight) or less of a fluorosurfactant. In such cases, it is possible to efficiently increase the hydrophilicity of the debris of the polishing pad and to suppress the generation of excessive bubbles during the polishing process.

[0079] Other additives The polishing composition for semiconductor processes may further contain other additives. The additives are not limited as long as they are those commonly applied in the CMP field. Exemplarily, the additive may be at least any one of an oxidizing agent, an acid component, a pH adjuster, a chelating agent, a dispersant, a polishing rate improver, a polishing regulator, a polishing pad protector, and a preservative.

[0080] The polishing composition for semiconductor processes can further contain an oxidizing agent. The oxidizing agent oxidizes metals such as tungsten to create an environment where the surface of the substrate can be more easily planarized, and plays a role in improving the polishing rate and the etching rate.

[0081] The oxidizing agent may be at least any 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 peroxydisulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide, and urea peroxide.

[0082] The polishing composition for semiconductor processes can contain 0.01 wt% to 5 wt% of an oxidizing agent. In such a case, the composition can exhibit excellent polishing characteristics with respect to metals, and can suppress the formation of an oxide film on the metal to be polished during the polishing process.

[0083] The polishing composition for semiconductor processes can further contain an acid component. Exemplarily, the acid component may be at least any 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, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, aspartic acid, tartaric acid, and salts thereof.

[0084] The polishing composition for semiconductor processes can further contain a pH adjuster together with the acid component. Exemplarily, the pH adjuster may be any one selected from the group consisting of ammonia, aminomethylpropanol, tetramethylammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium hydrogen carbonate, sodium carbonate, and combinations thereof.

[0085] The polishing composition for semiconductor processes can contain a chelating agent. The chelating agent can prevent the polished metal particles from adsorbing onto the surface of the surface to be polished.

[0086] The chelating agent may contain two or more carboxyl groups or alcohol groups in the molecule. As the chelating agent, two or more kinds of those containing two or more carboxyl groups or alcohol groups in the molecule can be applied. Specifically, the chelating agent can contain any one selected from the group consisting of EDTA (ethylenediaminetetraacetic acid), Glycine, carboxylic acids, and combinations thereof. The carboxylic acids mean compounds containing at least one or two or more carboxyl groups in the molecule.

[0087] The polishing composition for semiconductor processes can further contain a dispersant.

[0088] The dispersant can prevent the aggregation between the polishing particles in the polishing composition and disperse them uniformly. The cationic dispersant can increase the zeta potential of the polishing composition positively, and the anionic dispersant can decrease the zeta potential of the polishing composition negatively.

[0089] The dispersant can contain anionic low molecules, cationic polymers, organic acids, etc.

[0090] The anionic low molecules of the dispersant may be one or more selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, and combinations thereof.

[0091] The cationic polymer of the dispersant may be one or more selected from polylysine, polyethyleneimine, benzethonium chloride, bronidox, cetrimonium bromide, cetrimonium chloride, dimethyldioctadecylammonium chloride, tetramethylammonium hydroxide, distearyldimethylammonium chloride, polyarylamine, and combinations thereof.

[0092] 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.

[0093] The polishing rate improver is an additive for increasing the polishing rate of the substrate or wiring to be polished, and may be one or more selected from potassium nitrate, iron nitrate, ammonium hydroxide, citric acid, acetic acid, and combinations thereof.

[0094] The polishing regulator is for minimizing the adsorption of the polishing composition to the metal surface and may contain ammonium compounds, potassium nitrate, amino acids, salts thereof, and the like.

[0095] The polishing composition for semiconductor processes may contain a solvent. The solvent may be water, specifically ultrapure water.

[0096] Polishing characteristics of the polishing composition The polishing rate of the polishing composition for semiconductor processes with respect to the silicon oxide film may be 800 Å / min or more. The polishing rate may be 1000 Å / min or more. The polishing rate may be 1100 Å / min or more. The polishing rate may be 3000 Å / min or less. The polishing rate may be 2500 Å / min or less. The polishing rate may be 2000 Å / min or less.

[0097] The polishing rate of the polishing composition for semiconductor processes with respect to the tungsten film may be 50 Å / min or more. The polishing rate may be 70 Å / min or more. The polishing rate may be 500 Å / min or less. The polishing rate may be 300 Å / min or less. The polishing rate may be 200 Å / min or less.

[0098] The polishing selectivity of the silicon oxide film with respect to the tungsten film of the polishing composition for semiconductor processes 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.

[0099] In such a case, the polishing composition can exhibit an excellent polishing rate selectivity of the silicon oxide film compared to the polishing rate of tungsten.

[0100] The Ra value of the tungsten film measured after polishing with the polishing composition for semiconductor processes for 30 seconds may be 3 nm or less. The Ra value may be 2 nm or less. The Ra value may be 1.5 nm or less. The Ra value may be 1 nm or less. The polishing composition having such characteristics can provide a tungsten film with a reduced degree of damage due to corrosion when applied to polishing.

[0101] The Ra value is measured with an AFM (Atomic Force Microscope) in accordance with ISO 4287.

[0102] Polishing of each thin film is 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. As the polishing pad, the SR-300 model of SK Empulse Co., Ltd. can be applied.

[0103] When measuring the polishing rate of each thin film, as an example, the AP-300 model of CTS Co., Ltd. can be applied to the polishing machine.

[0104] Method for manufacturing a substrate The method for manufacturing the substrate of the embodiment includes a process of polishing the substrate by applying a polishing composition for semiconductor processes as a slurry.

[0105] The substrate may include at least any one of an insulating film, a metal wiring, and a barrier layer on its 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.

[0106] Specifically, in the process of polishing the substrate, the substrate to be polished is brought into contact with the polishing pad together with the polishing composition for semiconductor processes supplied from the injection nozzle, but the polishing head that fixes the substrate rotates, and the surface plate to which the polishing pad is attached may also rotate while performing the polishing.

[0107] The process of polishing the substrate may further include a process of conditioning the surface of the polishing pad before polishing, if necessary.

[0108] The polishing composition for semiconductor processes can polish the wafer in contact with the polishing pad while penetrating toward the substrate.

[0109] In the process of polishing the substrate, a pressure of 6.89 kPa to 48.26 kPa can be applied. The pressure may be 13.79 kPa to 34.47 kPa.

[0110] The process of polishing the substrate may be performed for 50 seconds to 10 minutes. However, it can be changed according to the desired degree of polishing.

[0111] The description of the polishing composition for semiconductor processes is omitted because it overlaps with the above content.

[0112] The method for manufacturing the substrate may further include a cleaning process of cleaning the polished substrate.

[0113] The cleaning step may be performed by a method of cleaning the polished substrate through purified water and an inert gas.

[0114] Hereinafter, specific examples will be described in more detail. The following examples are merely illustrative for helping the understanding of the present invention, and the scope of the present invention is not limited thereto.

[0115] Production Example: Production of Polishing Composition Example 1: To ultrapure water as a solvent, 3% by weight of colloidal silica surface-modified with 38 ppm (by weight) of (3-aminopropyl)triethoxysilane as polishing particles, 0.05% by weight of aminotetrazole as the first corrosion inhibitor, 0.05% by weight of imidazole as the second corrosion inhibitor, 20 ppm (by weight) of FS3100 from Capsstone as a fluorine-based surfactant, 1% by weight of sorbitol as a pad protector, and 2% by weight of sucrose were added and mixed to prepare a polishing composition of a total of 100% by weight.

[0116] Comparative Example 1: 0.05% by weight of aminotetrazole as a corrosion inhibitor and 2% by weight of sorbitol as a pad protector were applied, and a polishing composition of a total of 100% by weight was prepared under the same conditions as in Example 1 except that the average particle size of the polishing particles, the pH, the electrical conductivity, and the zeta potential of the polishing composition were applied as described in Table 2.

[0117] Comparative Example 2: No corrosion inhibitor was applied, 2% by weight of sorbitol was applied as a pad protector, and a polishing composition of a total of 100% by weight was prepared under the same conditions as in Example 1 except that the average particle size of the polishing particles, the pH, the electrical conductivity, and the zeta potential of the polishing composition were applied as described in Table 2.

[0118] 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 described in Table 1 below, and the pH, the electrical conductivity, and the zeta potential are described in Table 2 below.

[0119] Evaluation Example: Measurement of Static Etching Rate A substrate with a tungsten film formed thereon was immersed in polishing compositions for each of the examples and comparative examples for 10 minutes. Thereafter, the difference value in the thickness of the tungsten film on the substrate before and after immersion was measured, and the static etching rate was calculated by dividing the difference value by the immersion time.

[0120] The static etching rates for each of the examples and comparative examples were described in Table 2 below.

[0121] Evaluation Example: Measurement of Corrosion-Related Properties The corrosion current density I corr and corrosion potential E corr for the tungsten films of the polishing compositions for each of the examples and comparative examples were measured using a versaSTAT4, a potentiostat manufactured by AMETEK Scientific instruments. The measurement conditions were set as follows. -Reference Electrode:SCE Saturated Calomel(sat'd KCl) -Working Electrode Type:Solid Tungsten Electrode -RED Speed:0volt -Working Electrode Area:1cm 2 -Measured Open Circuit:131.27mV Endpoint Properties -Initial Potential:-1.5V(vs OC) -Final Potential:4V(vs Ref) Scan Properties -Step Height:10mV -Step Time:1s -Scan Rate:10mV / s -Total Points:551

[0122] The measured values and calculated values for each of the examples and comparative examples were described in Table 2 below.

[0123] Evaluation Example: Measurement of Polishing Characteristics and Detection of Defects The polishing composition was applied, and the upper surface of a 300-mm diameter wafer was polished with a CTS AP-300 polisher.

[0124] The polishing was carried out 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.

[0125] As the wafer, one including a tungsten pattern with a pattern density of 50% and a silicon oxide film was applied.

[0126] After the polishing, the differences in thickness between the silicon oxide film and the tungsten film before and after polishing were measured, and the polishing rate for each thin film of the polishing composition and the polishing selectivity of the silicon oxide film with respect to the tungsten film were calculated.

[0127] Thereafter, the number of defects detected on the silicon oxide film on the wafer surface was measured through Tenkor XP+ defect measurement equipment.

[0128] Also, in accordance with ISO 4287, the Ra value of the tungsten film on the substrate surface after polishing was measured with an AFM (Atomic Force Microscopy).

[0129] The measured values for each of the examples and comparative examples are shown in Table 3 below.

[0130] Evaluation Example: Measurement of Amount of Bubble Generation 3 L of the polishing compositions for each of the examples and comparative examples were charged into a 5-L glass reactor. The charged polishing compositions were stirred at 25°C at a speed of 1,000 RPM for 30 minutes with a four-blade blade having a total length of 10 cm. After 10 minutes had elapsed since the completion of the stirring, 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.

[0131] The calculated bubble volume values for each of the examples and comparative examples are shown in Table 3 below.

[0132]

Table 1

[0133]

Table 2

[0134]

Table 3

[0135] It can be seen from Table 2 that Example 1 has a lower corrosion potential value and a lower corrosion current density compared with Comparative Examples 1 and 2. That is, it was found that in Example 1, the corrosion starts earlier but the amount of corrosion is smaller compared with Comparative Examples 1 and 2.

[0136] In terms of the static etching rate, Example 1 showed a value of 4 Å / min or less, while Comparative Example 2 showed a value of 9 Å / min or more.

[0137] This means that in the case of Example 1 to which two kinds of corrosion inhibitors are applied, when the polishing composition contacts the tungsten film, the progress rate of corrosion is very slow compared with the polishing composition of Comparative Example 2.

[0138] In terms of the Ra value of the tungsten film, Example 1 showed a lower value compared with the comparative examples. This means that when polishing with the composition of Example 1, the degree of damage to the tungsten film due to corrosion is smaller compared with the comparative examples.

[0139] In terms of the volume of bubbles, both the examples and the comparative examples showed a value of 20 mL. This means that even when a surfactant is applied to the polishing composition, excessive bubbles do not occur during the polishing process.

[0140] Although the preferred embodiments have been described in detail above, the scope of the rights of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concepts of the embodiments defined in the appended claims also belong to the scope of the rights of the present invention.

Claims

1. comprising abrasive particles and a corrosion inhibitor; The corrosion inhibitor includes a first corrosion inhibitor which is an aminoazole-based compound and a second corrosion inhibitor which is a diazole-based compound; The pH is 2 to 5, A polishing composition for semiconductor processing, which has a static etching rate for a tungsten film of 6 Å / min or less.

2. I is the corrosion current density for the tungsten film. ｃｏｒｒ is 60 μA / cm ２ The polishing composition for semiconductor processing according to claim 1, which is as follows:

3. E is the corrosion potential for the tungsten film. ｃｏｒｒ The polishing composition for semiconductor processing according to claim 1, wherein the polishing potential is -30 mV or more.

4. 2. The polishing composition for semiconductor processing according to claim 1, comprising 0.07% by weight to 3% by weight of the corrosion inhibitor.

5. 2. The polishing composition for semiconductor processing according to claim 1, wherein a ratio of the content (weight basis) of the second corrosion inhibitor to the content (weight basis) of the first corrosion inhibitor is 0.6 to 2.

0.

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

7. Further comprising a fluorosurfactant, 2. The polishing composition for semiconductor processing according to claim 1, comprising the fluorosurfactant in an amount of 10 ppm (by weight) to 500 ppm (by weight).

8. 2. The polishing composition for semiconductor processing according to claim 1, wherein the polishing selectivity of a silicon oxide film to a tungsten film is 5 or more.

9. A method for producing a substrate, comprising a step of polishing a substrate by applying the polishing composition for semiconductor processing according to claim 1 as a slurry.

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