Polishing composition for semiconductor processes and method for manufacturing a 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] Examples of this work include polishing compositions for semiconductor processes and methods for manufacturing substrates using the same. [Background technology]

[0002] As semiconductor devices become even smaller and denser, increasingly finer pattern formation techniques are being used, resulting in more complex surface structures and larger step differences between interlayer films. In the manufacturing of semiconductor devices, chemical mechanical polishing (CMP) is used as a planarization technique to remove step differences in specific films formed on the substrate.

[0003] In the CMP (Chemical Polishing) process, the substrate is pressed and rotated while a slurry is supplied to a polishing pad, polishing the surface. The object to be planarized changes depending on the stage of the process, and the physical properties of the slurry applied also differ at each stage.

[0004] Polishing after the metal wiring has been formed requires maintaining a sufficient polishing rate and speed while minimizing dishing or erosion. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Korean Published Patent No. 10-2015-0036422 [Patent Document 2] Korean Published Patent No. 10-2020-0104257 [Overview of the project] [Problems that the invention aims to solve]

[0006] An object of an embodiment is to provide a polishing composition for a semiconductor process that can provide a polished surface with a reduced defect while showing a polishing rate of a certain level or more with respect to a silicon oxide film when polishing a substrate surface including a tungsten film and a silicon oxide film. **Means for Solving the Problems**

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

[0008] 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.

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

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

[0011] I which is the corrosion current density of the polishing composition for a semiconductor process with respect to a tungsten film , ,

[0016] , ,

[0015] may be 60 μA / cm 2 or less.

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

[0013] The polishing composition for a semiconductor process may contain 0.07 wt% to 3 wt% 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 aforementioned polishing composition for semiconductor processes may further contain a fluorine-based surfactant.

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

[0018] The polishing selectivity ratio of the silicon oxide film to the tungsten film of the aforementioned semiconductor process polishing composition may be 5 or more.

[0019] A method for manufacturing a substrate according to other embodiments of this specification includes a step of polishing the substrate by applying the semiconductor process polishing composition as a slurry. [Effects of the Invention]

[0020] The semiconductor process polishing composition in this embodiment exhibits a polishing speed above a certain level for the silicon oxide film when polishing the substrate surface containing a tungsten film and a silicon oxide film, and can provide a polished surface with reduced defects. [Best Mode for Carrying Out the Invention]

[0021] The embodiments are described in detail below so that they can be easily implemented by a person with ordinary skill in the art to which the embodiments belong. However, the embodiments can be implemented in a variety of different forms and are not limited to the embodiments described herein.

[0022] Terms of degree used herein, such as “about” and “substantially,” are used in the sense of the numerical value or close to the numerical value when tolerances for manufacture and material inherent to the meaning referred to are presented, and are used to prevent unscrupulous infringers from unfairly exploiting disclosures that refer to precise or absolute numerical values ​​to aid in understanding the specific examples.

[0023] Throughout this specification, the term “these combinations” as used in any expression in Markush form means one or more mixtures or combinations selected from the group of components described in the Markush form, and includes one or more of those components.

[0024] Throughout this specification, the phrase "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 term from one another unless otherwise specified.

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

[0027] In this specification, unless otherwise specified, singular expressions are interpreted to include singular or plural, as interpreted in the context.

[0028] The term "~-type compound" includes "~-compound" and its derivatives. For example, "aminoazole-type compound" refers to aminoazole compounds and derivatives of aminoazole compounds.

[0029] A substrate containing a tungsten film and an insulating film can be polished by applying a slurry with a high polishing selectivity ratio for the insulating film relative to the tungsten film. During the polishing process, defects caused by corrosion may occur in the tungsten film. Such defects tend to occur more frequently when using polishing compositions with a low pH.

[0030] The inventors of the embodiment applied a corrosion inhibitor containing a first corrosion inhibitor and a second corrosion inhibitor to the polishing composition and adjusted the static etching rate of the composition against the tungsten film. Through this, the inventors experimentally confirmed that they could provide a polishing composition that effectively suppresses the corrosion of the tungsten film even under low pH conditions and has excellent polishing properties against the silicon oxide film, thus completing the embodiment.

[0031] The following provides a detailed explanation of specific examples.

[0032] The semiconductor process polishing composition described in the example comprises polishing particles and a corrosion inhibitor.

[0033] Physical properties of abrasive compositions In practice, 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. Through this, the polishing properties of the polishing composition against the silicon oxide film can be improved while stably suppressing corrosion of the tungsten film by the acidic polishing composition.

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

[0035] The pH of the abrasive composition is measured using 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 higher. The pH may be 3.5 or higher.

[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, the oxidation rate of the tungsten film exposed to the polishing composition is controlled, and it is possible to suppress excessive damage to the tungsten film during the polishing process.

[0039] An embodiment is to control I, which is the corrosion current density of the polishing composition with respect to the tungsten film, corr 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 -20mV or greater. corr The value may be -15mV or greater. corr The value may be +20mV or less. In such cases, the surface of the tungsten film within 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] Corrosion current density I of the abrasive composition relative to the tungsten film corr and corrosion potential E corr This is measured using a potentiostat. 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 Weight: 10mV -Step Time: 1s -Scan Rate: 10mV / s -Total Points: 551

[0044] For example, I corr and E corr This can be measured using the versaSTAT4 model from AMETEK Scientific Instruments.

[0045] The electrical conductivity of the semiconductor process polishing composition may be 20 μS / cm or higher. The electrical conductivity may be 40 μS / cm or higher. The electrical conductivity may be 70 μS / cm or higher. The electrical conductivity may be 400 μS / cm or lower. The electrical conductivity may be 300 μS / cm or lower. The electrical conductivity may be 200 μS / cm or lower. In such cases, it is possible to suppress excessive damage to the tungsten film due to chemical reactions during the polishing process, and to enable the polishing composition to polish the surface to be polished at an excellent polishing speed.

[0046] The zeta potential of the semiconductor process polishing composition may be +5mV to +50mV. The zeta potential may be +10mV or higher. The zeta potential may be +40mV or lower.

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

[0048] In such cases, the abrasive composition exhibits stable dispersibility and can suppress the occurrence of defects on the polished surface due to aggregation of abrasive particles. Furthermore, the abrasive composition can demonstrate excellent polishing properties against silicon oxide films that exhibit a negative surface charge.

[0049] Composition of polishing composition abrasive particles Abrasive compositions may contain abrasive particles.

[0050] The abrasive particles may include metal oxide particles and / or silicon oxide particles. The abrasive particles may also include silica. The abrasive particles may also include 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 also be colloidal silica.

[0052] Abrasive particles may have a positive surface charge. Abrasive particles may be surface-modified to have a positive surface charge. Abrasive particles may be surface-modified with a compound having an amine group. Abrasive particles may be surface-modified with an aminosilane.

[0053] The aminosilane may be any one selected from the group consisting, for example, 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 may contain 15 ppm (by weight) to 200 ppm (by weight) of aminosilane. The polishing composition may contain 20 ppm (by weight) or more of aminosilane. The polishing composition may contain 25 ppm (by weight) or more of aminosilane. The polishing composition may contain 30 ppm (by weight) or more of aminosilane. The polishing composition may contain 150 ppm (by weight) or less of aminosilane. The polishing composition may contain 100 ppm (by weight) or less of aminosilane. The polishing composition may contain 70 ppm (by weight) or less of aminosilane. The polishing composition may contain 50 ppm (by weight) or less of aminosilane. In such cases, the polishing composition can exhibit an even better polishing rate against silicon oxide films, a smoother polishing of the substrate surface to be polished, and improved dispersibility. At the same time, residue of the surface modifier is generated, and its adsorption to the polished surface can be effectively suppressed.

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

[0056] The average particle size of the abrasive 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 abrasive composition exhibits excellent polishing efficiency on the surface to be polished, and moreover, the frequency of defects occurring on the surface to be polished can be stably controlled.

[0057] The average particle size refers to the average particle size of the primary particles of the abrasive particles.

[0058] Corrosion inhibitor The corrosion inhibitor in this example includes a first corrosion inhibitor which is an aminoazole compound, and a second corrosion inhibitor which is a diazole compound.

[0059] When the abrasive composition contains both a first corrosion inhibitor, which is an aminoazole compound, and a second corrosion inhibitor, which is a diazole compound, the corrosion resistance of the tungsten film to the acidic abrasive composition can be further effectively improved. This is thought to be because, when both the first and second corrosion inhibitors are applied to the composition, the corrosion inhibitors provide more dense protection to the surface of the tungsten film, reducing the degree to which the surface of the tungsten film is exposed to the abrasive composition.

[0060] The first corrosion inhibitor is an azole compound containing one or more amine groups as functional groups. An azole is a five-membered cyclic heterocompound containing one nitrogen and one or more non-carbon atoms in its 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 five-membered cyclic compound containing three carbon atoms and two nitrogen atoms in the ring. The second corrosion inhibitor is distinguished from the first corrosion inhibitor by not containing 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 may contain 0.07% to 3% by weight of a corrosion inhibitor. The polishing composition may contain 0.09% or more by weight of a corrosion inhibitor. The polishing composition may contain 2% or less by weight of a corrosion inhibitor. The polishing composition may contain 1% or less by weight of a corrosion inhibitor. In such cases, the degree of damage to the tungsten film due to chemical reactions 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 may be 0.6 to 2.0. The ratio may be 0.8 or higher. The ratio may be 1.6 or lower. In such cases, the oxidation of tungsten during the polishing process can be suppressed even more effectively.

[0066] The abrasive composition may contain 0.01% to 0.2% by weight of the first corrosion inhibitor. The abrasive composition may contain 0.02% or more by weight of the first corrosion inhibitor. The abrasive composition may contain 0.04% or more by weight of the first corrosion inhibitor. The abrasive composition may contain 0.1% or less by weight of the first corrosion inhibitor.

[0067] The abrasive composition may contain 0.01% to 0.2% by weight of the secondary corrosion inhibitor. The abrasive composition may contain 0.02% or more by weight of the secondary corrosion inhibitor. The abrasive composition may contain 0.04% or more by weight of the secondary corrosion inhibitor. The abrasive composition may contain 0.1% or less by weight of the secondary corrosion inhibitor.

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

[0069] Fluorine-based surfactants One concrete example is the application of a fluorine-based surfactant to the abrasive composition. The surfactant adheres to the surface of organic particles generated during the polishing process, thereby suppressing the adsorption of these particles onto the surface of the tungsten film or silicon oxide film. Furthermore, the surfactant adheres to the surface of the silicon oxide film, preventing abrasive particles from adsorbing onto the surface of the silicon oxide film or forming scratches on the surface.

[0070] The fluorine-based surfactant may also be a fluoroalkylalkylene oxide compound. The fluorine-based surfactant may also be a compound according to the following chemical formula 1.

[0071] [C1] R f -(R en -O) n -H

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

[0073] In the above chemical formula 1, R f This may be a perfluoroalkyl group having 3 to 10 carbon atoms.

[0074] The fluorine-based surfactant may also be a polymer-based surfactant. The fluorine-based surfactant 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] Fluorine-based surfactants having the characteristics described above have a controlled main chain length and can efficiently remove organic particles. Furthermore, they can prevent excessive deterioration of the dispersibility of the abrasive composition due to the surfactant.

[0076] The weight-average molecular weight of polymeric surfactants is measured by GPC (Gel Permeation Chromatography).

[0077] In practice, the content of the fluorine-based surfactant can be adjusted within a predetermined range. Through this, it is possible to suppress the adhesion of organic particles to the polished surface after polishing, and to prevent excessive foaming of the polishing composition during the polishing process, thereby preventing a decrease in processability.

[0078] The polishing composition for semiconductor processes may contain 10 ppm (by weight) or more of a fluorine-based surfactant. The polishing composition for semiconductor processes may contain 20 ppm (by weight) or more of a fluorine-based surfactant. The polishing composition for semiconductor processes may contain 50 ppm (by weight) or more of a fluorine-based surfactant. The polishing composition for semiconductor processes may contain 100 ppm (by weight) or more of a fluorine-based surfactant. The polishing composition for semiconductor processes may contain 150 ppm (by weight) or more of a fluorine-based surfactant. The polishing composition for semiconductor processes may contain 500 ppm (by weight) or less of a fluorine-based surfactant. The polishing composition for semiconductor processes may contain 450 ppm (by weight) or less of a fluorine-based surfactant. In such cases, the hydrophilicity of the debris on the polishing pad can be efficiently increased, and the generation of excessive foam during the polishing process can be suppressed.

[0079] Other additives Polishing compositions for semiconductor processes may further contain other additives. The additives are not limited as long as they are commonly used in the field of CMP. Exemplary examples of additives may be at least one of oxidizing agents, acidic components, pH adjusters, chelating agents, dispersants, polishing rate enhancers, polishing modifiers, polishing pad protectants, and preservatives.

[0080] Polishing compositions for semiconductor processes may further contain an oxidizing agent. The oxidizing agent plays a role in improving polishing and etching speeds by creating an environment in which the substrate surface can be flattened more easily by oxidizing metals such as tungsten.

[0081] The oxidizing agent may 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 sulfate peroxide, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide, and urea peroxide.

[0082] Polishing compositions for semiconductor processes may contain 0.01% to 5% by weight of an oxidizing agent. In such cases, the composition can exhibit excellent polishing properties for metals and can suppress the formation of oxide films on the metal being polished during the polishing process.

[0083] The polishing composition for semiconductor processes may further contain an acid component. The acid component may be at least one selected from the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, bromate, 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, as an example.

[0084] Polishing compositions for semiconductor processes may further contain a pH adjuster along with an acid component. 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 bicarbonate, sodium carbonate, and combinations thereof.

[0085] Polishing compositions for semiconductor processes may contain chelating agents. Chelating agents can prevent polished metal particles from adhering to the surface of the polished material.

[0086] The chelating agent may contain two or more carboxyl groups or alcohol groups in its molecule. Two or more chelating agents containing two or more carboxyl groups or alcohol groups in their molecule can be applied. Specifically, the chelating agent may include 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 more carboxyl groups in their molecule.

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

[0088] Dispersants can prevent aggregation between abrasive particles within the abrasive composition and allow for uniform dispersion. Cationic dispersants can increase the zeta potential of the abrasive composition positively, while anionic dispersants can decrease the zeta potential of the abrasive composition negatively.

[0089] Dispersants may include anionic low molecular weight molecules, cationic polymers, organic acids, etc.

[0090] 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.

[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 dispersant organic acid 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 enhancer 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 modifier is intended to minimize the adsorption of the polishing composition onto the metal surface and may include ammonium compounds, potassium nitrate, amino acids, and their salts.

[0095] Polishing compositions for semiconductor processes may contain a solvent. The solvent may be water, and more specifically, ultrapure water.

[0096] Polishing properties of polishing compositions The polishing rate of the semiconductor process polishing composition against 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 semiconductor process polishing composition against a 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 ratio of the silicon oxide film to the tungsten film in the semiconductor process polishing composition may be 5 or more. The polishing selectivity ratio may be 6 or more. The polishing selectivity ratio may be 7 or more. The polishing selectivity ratio may be 20 or less.

[0099] In such cases, the abrasive composition can exhibit a superior selectivity ratio for the abrasive rate of silicon oxide films compared to the abrasive rate of tungsten.

[0100] The Ra value of a tungsten film measured after polishing with a semiconductor process polishing composition 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. A 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 using an AFM (Atomic Force Microscope) in accordance with ISO 4287.

[0102] Polishing of each thin film is performed under the following conditions: pressure 2.2 psi, carrier speed 87 rpm, platen speed 93 rpm, and slurry flow rate 250 ml / min. SK Empulse's SR-300 model polishing pad can be used.

[0103] When measuring the polishing rate for each thin film, a polishing machine such as the CTS AP-300 model can be used as an example.

[0104] Substrate manufacturing method The manufacturing method of the substrate in the embodiment includes a step of polishing the substrate by applying a semiconductor process polishing composition as a slurry.

[0105] The substrate may include at least one of an insulating film, metal wiring, and a barrier layer on its upper surface. The metal wiring may include copper or tungsten. If the metal wiring includes copper, the barrier layer may include tantalum and its nitride. If the metal wiring includes tungsten, the barrier layer may include titanium and its nitride.

[0106] Specifically, the process of polishing a substrate involves bringing the substrate to be polished into contact with a polishing pad together with a semiconductor process polishing composition supplied from a spray nozzle. This process can be carried out while the polishing head that holds the substrate in place rotates, and the platen to which the polishing pad is attached also rotates.

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

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

[0109] During the process of polishing the substrate, a pressure of 6.89 kPa to 48.26 kPa may be applied. The aforementioned pressure may also be between 13.79 kPa and 34.47 kPa.

[0110] The process of polishing the substrate may be carried out for 50 seconds to 10 minutes. However, this can be adjusted depending on the desired degree of polishing.

[0111] The description of the aforementioned polishing composition for semiconductor processes will be omitted as it will be redundant with the content described above.

[0112] The method for manufacturing the substrate may further include a cleaning step for cleaning the substrate after polishing.

[0113] The cleaning process may be carried out by cleaning the polished substrate through purified water and an inert gas.

[0114] The following describes specific examples in more detail. The following examples are merely illustrative to aid in understanding the present invention, and the scope of the present invention is not limited thereto.

[0115] Manufacturing example: Manufacturing of abrasive compositions Example 1: To ultrapure water, which is the solvent, 3% by weight of colloidal silica surface-modified with (3-aminopropyl)triethoxysilane 38 ppm (by weight) as abrasive particles, 0.05% by weight of aminotetrazole as a primary corrosion inhibitor, 0.05% by weight of imidazole as a secondary corrosion inhibitor, 20 ppm (by weight) of Capstone's FS3100 as a fluorine-based surfactant, and 1% by weight of sorbitol and 2% by weight of sucrose as pad protectants were added and mixed to prepare a total abrasive composition of 100% by weight.

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

[0117] Comparative Example 2: A total of 100% by weight of abrasive composition was prepared under the same conditions as in Example 1, except that no corrosion inhibitor was applied, 2% by weight of sorbitol was applied as a pad protectant, and the average particle size of the abrasive particles, the pH of the abrasive composition, the electrical conductivity, and the zeta potential 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 shown in Table 1 below, and the pH, electrical conductivity, and zeta potential are shown in Table 2 below.

[0119] Evaluation example: Measurement of static etching rate Substrates with tungsten films formed on them were immersed for 10 minutes in polishing compositions for each example and comparative example. Then, the difference 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 this difference by the immersion time.

[0120] The static etching rates for each example and comparative example are shown in Table 2 below.

[0121] Evaluation example: Measurement of corrosion-related properties Corrosion current density I of polishing compositions for tungsten films in each example and comparative example corr and corrosion potential E corr The measurement was performed using the versaSTAT4 potentiostat from 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 Weight: 10mV -Step Time: 1s -Scan Rate: 10mV / s -Total Points: 551

[0122] The measured values ​​and calculated values ​​for each example and comparative example are shown in Table 2 below.

[0123] Evaluation example: Measurement of polishing characteristics and detection of defects The polishing composition was applied, and the top surface of a 300 mm diameter wafer was polished using a CTS AP-300 polishing machine.

[0124] Polishing was performed under the following conditions: polishing time 60 seconds, pressure 2.2 psi, carrier speed 93 rpm, platen speed 87 rpm, and slurry flow rate 300 ml / min.

[0125] The wafer used contained a tungsten pattern with a pattern density of 50% and a silicon oxide film.

[0126] After polishing was completed, the difference in thickness between the silicon oxide film and the tungsten film before and after polishing was measured, and the polishing rate of each thin film in the polishing composition, as well as the polishing selectivity ratio of the silicon oxide film to the tungsten film, were calculated.

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

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

[0129] The measured values ​​for each example and comparative example are shown in Table 3 below.

[0130] Evaluation example: Measurement of bubble generation amount Three liters of each polishing composition for the examples and comparative examples were placed in a 5-liter glass reactor. The polishing compositions were stirred with a 10 cm long, four-blade stirring device at 25°C at a speed of 1,000 RPM for 30 minutes. Ten minutes after the end of stirring, the height of the bubbles formed in the glass reactor was measured. The volume of the bubbles was calculated from the height and the inner diameter of the glass reactor containing the polishing compositions.

[0131] The calculated bubble volume values ​​for each example and comparative example are shown in Table 3 below.

[0132] [Table 1]

[0133] [Table 2]

[0134] [Table 3]

[0135] Table 2 shows that Example 1 has a lower corrosion potential value and a lower corrosion current density compared to Comparative Examples 1 and 2. In other words, Example 1 shows that corrosion begins even earlier than in Comparative Examples 1 and 2, but the amount of corrosion is even smaller.

[0136] In terms of 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 Example 1, where two types of corrosion inhibitors were applied, the rate of corrosion progression when the abrasive composition came into contact with the tungsten film was significantly slower than that of the abrasive composition in Comparative Example 2.

[0138] In terms of the Ra value of the tungsten film, Example 1 showed a lower value compared to the comparative example. This means that when polishing with the composition of Example 1, the degree to which the tungsten film is damaged by corrosion is less than that of the comparative example.

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

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

Claims

1. Contains abrasive particles and corrosion inhibitors, The corrosion inhibitor comprises 0.01% to 0.2% by weight of a first corrosion inhibitor which is an aminoazole compound, and 0.01% to 0.2% by weight of a second corrosion inhibitor which is a diazole compound that does not contain an amine group. The first corrosion inhibitor comprises aminotetrazole, and the second corrosion inhibitor comprises imidazole. The pH is between 2 and 5. The static etching rate for the tungsten film is 6 Å / min or less. A polishing composition for semiconductor processes, wherein the corrosion current density Icorr for a tungsten film is 60 μA / cm² or less.

2. E is the corrosion potential for a tungsten film. ｃｏｒｒ The semiconductor process polishing composition according to claim 1, wherein the voltage is -30 mV or higher.

3. The semiconductor polishing composition according to claim 1, wherein the ratio of the content (by weight) of the second corrosion inhibitor to the content (by weight) of the first corrosion inhibitor is 0.6 to 2.

0.

4. The corrosion inhibitor suppresses corrosion of the tungsten film, as described in claim 1, for the semiconductor process polishing composition.

5. It further contains a fluorine-based surfactant, The semiconductor process polishing composition according to claim 1, comprising 10 ppm (by weight) to 500 ppm (by weight) of the fluorine-based surfactant.

6. The semiconductor process polishing composition according to claim 1, wherein the polishing selectivity ratio of the silicon oxide film to the tungsten film is 5 or more.

7. A method for manufacturing a substrate, comprising the step of polishing a substrate by applying the semiconductor process polishing composition described in claim 1 as a slurry.

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