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

Abstract

To provide a polishing composition for semiconductor processes that has excellent dispersibility and can embody a polished surface with a defect count regulated below a certain level when applied to chemical mechanical polishing (CMP) processes.SOLUTION: A polishing composition for semiconductor processes according to an embodiment of the present description contains abrasive particles and a first metal ion, which is an alkali metal ion. The abrasive particles present a surface positive charge. The content of the first metal ion in the polishing composition for semiconductor processes is 15 ppm (weight basis) to 100 ppm (weight basis). Such polishing compositions have excellent dispersion and can provide polished surfaces with defect counts regulated below a certain level.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] As semiconductor elements become finer and denser, finer pattern formation techniques are used, which makes the surface structure of the semiconductor elements more complicated and the steps in the interlayer films larger. In manufacturing semiconductor elements, a chemical mechanical polishing (hereinafter referred to as "CMP") process is used as a planarization technique for removing steps in a specific film formed on a substrate.

[0003] In the CMP process, the surface of the substrate is polished by applying pressure and rotating the substrate while a slurry is applied to the polishing pad. The object to be planarized varies depending on the process stage, and the properties of the slurry used at this time also vary.

[0004] Polishing after the metal wiring is formed must maintain a sufficient polishing rate and polishing speed while minimizing dishing or erosion. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent No. 10-2082922 [Patent Document 2] Korean Patent Publication No. 10-2002-0029158 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the embodiment is to provide a polishing composition for semiconductor processing that has excellent dispersibility and can realize a polished surface with a number of defects controlled to a certain level or less when applied to a CMP process. [Means for solving the problem]

[0007] A polishing composition for semiconductor processing according to one embodiment of the present specification includes abrasive particles and a first metal ion which is an alkali metal ion.

[0008] The abrasive particles exhibit a positive surface charge.

[0009] The polishing composition for semiconductor processing has a content of the first metal ion of 15 ppm (by weight) to 100 ppm (by weight).

[0010] The polishing composition for semiconductor processing may include a second metal ion selected from the group consisting of iron ions, copper ions, nickel ions, aluminum ions, calcium ions, zinc ions, and combinations thereof.

[0011] The polishing composition for semiconductor processing may have a ratio of the content (weight basis) of the first metal ion to the content (weight basis) of the second metal ion of 15 or more.

[0012] The abrasive particles may have a zeta potential of +10 mV to +50 mV at a pH of 2 to 5.5.

[0013] The abrasive particles may be surface-modified with a compound having an amine group.

[0014] The polishing composition for semiconductor processing may contain 1 wt % to 10 wt % of the abrasive particles.

[0015] The polishing composition for semiconductor processing may have an electrical conductivity of 10 μS / cm to 300 μS / cm.

[0016] The polishing composition for semiconductor processing may further include a fluorine-based surfactant.

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

[0018] The polishing composition for semiconductor processing may have a viscosity at 25°C of 0.8 cP to 2.0 cP.

[0019] A method for manufacturing a substrate according to another embodiment of the present specification includes a step of polishing a substrate by applying the polishing composition for semiconductor processing as a slurry. Effect of the Invention

[0020] The polishing composition for semiconductor processing according to the embodiment has excellent dispersibility, and when applied to a CMP process, it can realize a polished surface with a number of defects controlled to a certain level or less. BEST MODE FOR CARRYING OUT THEINVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail with reference to the accompanying drawings, in which: FIG. 1 is a block diagram of a method for manufacturing a semiconductor device according to an embodiment of the present invention;

[0022] As used herein, terms of degree such as "about," "substantially," and the like are used in a numerical or approximate sense when the tolerances of manufacturing and materials inherent in the referred meaning are given, and are used to prevent unscrupulous infringers from unfairly taking advantage of disclosures in which precise or absolute numerical values ​​are referred to to aid in the understanding of the embodiments.

[0023] Throughout this specification, the term "combinations thereof" in a Markush form phrase means a mixture or combination of one or more selected from the group of elements set forth in the Markush form phrase, including one or more selected from the group of elements.

[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 identical terms from one another, unless otherwise specified.

[0026] In this specification, the term "B is located on A" means that B can be located on A, or B can be located on A with another layer located therebetween, and is not to be interpreted as being limited to B being located in contact with the surface of A.

[0027] In this specification, the term "singular" is to be construed as including the singular or plural as the context requires, unless otherwise specified.

[0028] Hereinafter, the embodiment will be described in detail.

[0029] Metal ions In the polishing composition for semiconductor processing according to the embodiment, in order to further improve the dispersibility of abrasive particles, etc., a first metal ion, which is an alkali metal ion, and abrasive particles exhibiting a positive charge on the surface may be applied together.

[0030] Unlike other metal ions, alkali metal ions are not highly reactive in the polishing composition and do not easily form metal oxides on the polished surface during the polishing process. When alkali metal ions are added to the polishing composition, electrostatic repulsion is formed between the alkali metal ions and the polishing particles exhibiting a positive surface charge, and the dispersibility of the polishing composition can be improved through the alkali metal ions.

[0031] Alkali metal ions are Group 1 elements and can include lithium ions, sodium ions, potassium ions, rubidium ions, cesium ions, and francium ions.

[0032] The content of the first metal ion in the polishing composition for semiconductor processing may be 15 ppm (weight basis) to 100 ppm (weight basis). The content of the first metal ion may be 20 ppm (weight basis) or more. The content of the first metal ion may be 25 ppm (weight basis) or more. The content of the first metal ion may be 28 ppm (weight basis) or more. The content of the first metal ion may be 32 ppm (weight basis) or more. The content of the first metal ion may be 70 ppm (weight basis) or less. The content of the first metal ion may be 60 ppm (weight basis) or less. The content of the first metal ion may be 50 ppm (weight basis) or less. In this case, the dispersibility of the abrasive particles can be effectively improved. At the same time, it is possible to prevent a considerable number of first metal ions from being excessively adsorbed on the polished surface, which deteriorates the electrical characteristics of the element, or prevents the polishing characteristics of the polishing composition for the polished surface from being excessively reduced.

[0033] The polishing composition for semiconductor processing may contain a second metal ion selected from the group consisting of iron ions, copper ions, nickel ions, aluminum ions, calcium ions, zinc ions, and combinations thereof.

[0034] The polishing composition may have a ratio of the first metal ion content (by weight) to the second metal ion content (by weight) of 15 or more.

[0035] The second metal ion has a relatively high reactivity, and therefore can contribute to adjusting the polishing properties of the polishing composition for the tungsten film. However, the metal ion may easily form precipitates on the polished surface by reacting with other compounds during the polishing and cleaning process, and the metal ion may be adsorbed on the surface of the substrate, thereby degrading the electrical properties of the manufactured device. In the embodiment, the ratio of the content of the first metal ion to the content of the second metal ion is adjusted to reduce the frequency of defects on the substrate surface to a certain level or less, and the dispersibility and polishing properties of the polishing composition can be effectively improved.

[0036] The ratio of the content (by weight) of the first metal ion to the content (by weight) of the second metal ion in the polishing composition may be 15 or more. The ratio may be 20 or more. The ratio may be 25 or more. The ratio may be 30 or more. The ratio may be 35 or more. The ratio may be 40 or more. The ratio may be 100 or less. The ratio may be 80 or less. The ratio may be 60 or less. The ratio may be 50 or less. In such cases, a decrease in element yield due to the addition of metal ions can be stably suppressed.

[0037] The polishing composition may contain 1.3 ppm (by weight) or less of the second metal ion. The polishing composition may contain 1.2 ppm (by weight) or less of the second metal ion. The polishing composition may contain 1 ppm (by weight) or less of the second metal ion. The polishing composition may contain 0.01 ppm (by weight) or more of the second metal ion. In such a case, the polishing characteristics for the tungsten film can be adjusted within an appropriate range, and contamination of the polished surface by the metal ion can be effectively suppressed.

[0038] The metal ion content of the polishing composition is measured by ICP-OES (Inductively Coupled Plasma-Optical Emission Spectroscopy).

[0039] abrasive particles The polishing composition can include abrasive particles.

[0040] The abrasive particles can include metal oxide particles and / or silicon oxide particles. The abrasive particles can include silica. The abrasive particles can include colloidal silica.

[0041] The abrasive particles may contain 70% or more by weight of colloidal silica. The abrasive particles may contain 80% or more by weight of colloidal silica. The abrasive particles may contain 90% or more by weight of colloidal silica. The abrasive particles may be colloidal silica.

[0042] The abrasive particles can have a positive charge on the surface. The abrasive particles having a positive surface charge refer to abrasive particles having a positive zeta potential in the polishing composition. Specifically, the abrasive particles having a positive surface charge refer to abrasive particles having a positive zeta potential under a pH condition of 2 to 5.5.

[0043] The abrasive particles exhibiting a positive surface charge can exhibit excellent dispersibility due to electrostatic interaction with the first metal ion. In addition, such particles can have the property of easily contacting the surface of the silicon oxide film exhibiting a negative charge. Through this, the abrasive particles can impart improved polishing properties to the silicon oxide film to the polishing composition.

[0044] The abrasive particles may have a zeta potential of +10 mV to +50 mV at pH 2 to 5.5. The zeta potential may be +15 mV or more. The zeta potential may be +20 mV or more. In such a case, the abrasive particles can be easily dispersed due to interaction with the first metal ion, and the polishing composition can have an excellent polishing rate for silicon oxide film.

[0045] The zeta potential of the abrasive particles is measured using a particle size analyzer. For example, the particle size analyzer may be a Nano-ZS model manufactured by Malvern.

[0046] The abrasive particles may be surface-modified so that the surface has a positive charge. The abrasive particles may be surface-modified with a compound having an amine group. The abrasive particles surface-modified with a compound having an amine group is interpreted as including not only abrasive particles surface-modified with a compound having an amine group alone, but also abrasive particles surface-modified by applying both a compound having an amine group and another compound not having an amine group.

[0047] The abrasive particles may be surface-modified with a compound containing aminosilane.The abrasive particles may be surface-modified with aminosilane.

[0048] The aminosilane may be, for example, 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.

[0049] The polishing composition for semiconductor process may contain 15 ppm (weight basis) to 200 ppm (weight basis) of aminosilane. The polishing composition for semiconductor process may contain 20 ppm (weight basis) or more of aminosilane. The polishing composition for semiconductor process may contain 25 ppm (weight basis) or more of aminosilane. The polishing composition for semiconductor process may contain 30 ppm (weight basis) or more of aminosilane. The polishing composition for semiconductor process may contain 150 ppm (weight basis) or less of aminosilane. The polishing composition for semiconductor process may contain 100 ppm (weight basis) or less of aminosilane. The polishing composition for semiconductor process may contain 70 ppm (weight basis) or less of aminosilane. The polishing composition for semiconductor process may contain 50 ppm (weight basis) or less of aminosilane. In such a case, the electrostatic repulsion between the abrasive particles and the first metal ions can be adjusted to an appropriate strength. At the same time, the polishing composition can have a better polishing rate for silicon oxide film.

[0050] The polishing composition for semiconductor processing may contain 1 wt % to 10 wt % of abrasive particles. The polishing composition for semiconductor processing may contain 2 wt % or more of abrasive particles. The polishing composition for semiconductor processing may contain 8 wt % or less of abrasive particles. The polishing composition for semiconductor processing may contain 5 wt % or less of abrasive particles. In such cases, the polishing composition has an excellent polishing rate for the polished surface and can stably suppress aggregation of the abrasive particles.

[0051] The abrasive particles may have an average particle size of 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 polished surface, and can stably adjust the frequency of defects occurring on the polished surface.

[0052] The average particle size means the average particle size of the primary particles of the abrasive particles.

[0053] Physical properties of the polishing composition The pH of the polishing composition for semiconductor processing may be 2 to 5.5. The pH may be 2.5 or more. The pH may be 3 or more. The pH may be 3.5 or more. The pH may be 5 or less. In such cases, the abrasive particles have a relatively strong positive charge and can be dispersed more easily. In addition, the polishing composition can exhibit a certain level or more of polishing rate for silicon oxide film.

[0054] The pH of the polishing composition is measured with a pH meter.

[0055] The zeta potential of the polishing composition for semiconductor processing may be +10 mV to +50 mV. The zeta potential may be +15 mV or more. The zeta potential may be +20 mV or more. In such a case, the frequency of scratches occurring on the polished surface due to aggregation of abrasive particles or adsorption of abrasive particles to the polished surface can be effectively reduced.

[0056] The zeta potential of the polishing composition is measured using a particle size analyzer. For example, the particle size analyzer may be a Nano-ZS model manufactured by Malvern.

[0057] The electrical conductivity of the polishing composition for semiconductor processing may be 10 μS / cm to 300 μS / cm. The electrical conductivity may be 20 μS / cm or more. The electrical conductivity may be 30 μS / cm or more. The electrical conductivity may be 40 μS / cm or more. The electrical conductivity may be 50 μS / cm or more. The electrical conductivity may be 200 μS / cm or less. The electrical conductivity may be 150 μS / cm or less. The electrical conductivity may be 120 μS / cm or less. In this case, by adjusting the number of first metal ions contained in the polishing composition, it is possible to effectively suppress aggregation of abrasive particles and to suppress excessive corrosion of metal wiring formed on the polished surface during the polishing process.

[0058] The viscosity of the polishing composition for semiconductor processing at 25°C may be 0.8 cP to 2.0 cP. The viscosity may be 0.9 cP or more. The viscosity may be 1.5 cP or less. The viscosity may be 1.2 cP or less. In such cases, excessive aggregation between components in the polishing composition can be suppressed, and defects such as scratches can be effectively suppressed from occurring on the polished surface.

[0059] The viscosity of the polishing composition is measured with a viscometer.

[0060] Composition of the polishing composition Fluorosurfactants The polishing composition for semiconductor processing according to the embodiment may further include a fluorine-based surfactant. The surfactant may be attached to a silicon oxide film to effectively prevent abrasive particles exhibiting a positive charge on the surface from being strongly adsorbed to the oxide film. In addition, the surfactant may be attached to organic particles to facilitate the removal of the particles.

[0061] The fluorosurfactant may be a fluoroalkyl alkylene oxide compound. The fluorosurfactant may be a compound according to the following formula 1:

[0062] [C1] R f -(R en -O) n -H

[0063] In the above Chemical Formula 1, R f is a fluoroalkyl group having 3 to 10 carbon atoms, en is an alkylene group having 2 or 3 carbon atoms, and n is an integer of 2 to 15.

[0064] In the above formula 1, R f may be a perfluoroalkyl group having 3 to 10 carbon atoms.

[0065] The fluorosurfactant may be a polymer 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.

[0066] The fluorosurfactant having the above characteristics has a controlled main chain length, and can efficiently adhere to the surface of the silicon oxide film, and can prevent the dispersibility of the polishing composition from being excessively deteriorated by the surfactant.

[0067] The weight average molecular weight of the polymer surfactant is measured by GPC (Gel Permeation Chromatography).

[0068] In the embodiment, the content of the fluorosurfactant may be adjusted within a preset range, thereby preventing adhesion of abrasive particles to the polished surface after polishing and preventing excessive foaming in the polishing composition during the polishing process, thereby preventing deterioration of processability.

[0069] The polishing composition for semiconductor process may contain 10 ppm (weight basis) or more of fluorosurfactant. The polishing composition for semiconductor process may contain 20 ppm (weight basis) or more of fluorosurfactant. The polishing composition for semiconductor process may contain 50 ppm (weight basis) or more of fluorosurfactant. The polishing composition for semiconductor process may contain 100 ppm (weight basis) or more of fluorosurfactant. The polishing composition for semiconductor process may contain 150 ppm (weight basis) or more of fluorosurfactant. The polishing composition for semiconductor process may contain 500 ppm (weight basis) or less of fluorosurfactant. The polishing composition for semiconductor process may contain 450 ppm (weight basis) or less of fluorosurfactant. In such a case, it is possible to efficiently suppress the adsorption of abrasive particles to the oxide film and to suppress the generation of excessive bubbles during the polishing process.

[0070] Other Additives The polishing composition for semiconductor processing may further include other additives. The additives are not limited as long as they are generally applied in the CMP field. For example, the additives may be at least one of an oxidizing agent, an acid component, a pH adjusting agent, a chelating agent, a dispersing agent, a polishing rate improving agent, a polishing adjusting agent, a polishing pad protecting agent, and a preservative.

[0071] The polishing composition for semiconductor processing may further include an oxidizing agent. The oxidizing agent oxidizes metals such as tungsten to create an environment in which the surface of the substrate can be more easily planarized, and serves to improve the polishing rate and etching rate.

[0072] 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 persulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide, and urea peroxide.

[0073] The polishing composition for semiconductor processing may contain 0.01% by weight to 5% by weight of an oxidizing agent. In this case, the composition may exhibit excellent polishing properties for metals and may suppress the formation of an oxide film on the metal to be polished during the polishing process.

[0074] The polishing composition for semiconductor processing may further include an acid component. The acid component may 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, 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.

[0075] The polishing composition for semiconductor processing may further include a pH adjuster together with the acid component. The pH adjuster may be, for example, 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.

[0076] The polishing composition for semiconductor processing may contain a chelating agent, which can prevent polished metal particles from being adsorbed on the surface of the surface to be polished.

[0077] The chelating agent may contain two or more carboxyl groups or alcohol groups in the molecule. As the chelating agent, two or more types of chelating agents containing two or more carboxyl groups or alcohol groups in the molecule can be applied. Specifically, the chelating agent may include any one selected from the group consisting of EDTA (ethylenediaminetetraacetic acid), glycine, carboxylic acids, and combinations thereof. The carboxylic acids refer to compounds containing at least one or two or more carboxyl groups in the molecule.

[0078] The polishing composition for semiconductor processing may further contain a dispersant.

[0079] The dispersant can prevent agglomeration between abrasive particles in the polishing composition and disperse them uniformly. The cationic dispersant can increase the zeta potential of the polishing composition to a positive value, and the anionic dispersant can decrease the zeta potential of the polishing composition to a negative value.

[0080] The dispersant may include anionic small molecules, cationic polymers, organic acids, and the like.

[0081] The anionic small molecule of the dispersing agent may be one or more selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid, and combinations thereof.

[0082] The cationic polymer of the dispersing agent 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.

[0083] The organic acid of the dispersing agent may be one or more selected from hydroxylbenzoic acid, ascorbic acid, picolinic acid, glutamic acid, tryptophan, aminobutyric acid, and combinations thereof.

[0084] 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.

[0085] The polishing modifier is intended to minimize the adsorption of the polishing composition to the metal surface, and may include ammonium compounds, potassium nitrate, amino acids, salts thereof, and the like.

[0086] The polishing composition for semiconductor processing may include a solvent, which may be water, and more specifically, ultrapure water.

[0087] Polishing properties of the polishing composition The polishing rate of the polishing composition for semiconductor processing against a silicon oxide film may be 950 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.

[0088] The polishing rate of the polishing composition for semiconductor processing against a tungsten film 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.

[0089] The polishing selectivity of the polishing composition for semiconductor processing for a silicon oxide film to a 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 15 or less.

[0090] In such a case, the polishing composition can exhibit a superior silicon oxide polishing rate selectivity ratio compared to the tungsten polishing rate.

[0091] The Ra value of a tungsten film measured after polishing with the polishing composition for semiconductor processing for 30 seconds may be 1 nm or less. The Ra value may be 0.9 nm or less. The Ra value may be 0.8 nm or less. The Ra value may be 0.1 nm or more. A polishing composition having such characteristics may provide a tungsten film with reduced damage due to corrosion when applied to polishing.

[0092] The Ra value is measured using an AFM (Atomic Force Microscope) in accordance with ISO 4287.

[0093] Polishing for each thin film is performed under the conditions of pressure 2.2 psi, carrier speed 87 rpm, platen speed 93 rpm, and slurry flow rate 250 ml / min. The polishing pad may be SR-300 model manufactured by SK Empulse.

[0094] When measuring the polishing rate for each thin film, the polishing machine may be, for example, the AP-300 model manufactured by CTS.

[0095] Substrate manufacturing method A method for manufacturing a substrate according to an embodiment includes polishing a substrate by applying a polishing composition for semiconductor processing as a slurry.

[0096] The substrate may include at least one of an insulating film, a metal wiring, and a barrier layer on an 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.

[0097] Specifically, the process of polishing a substrate may be performed by contacting the substrate to be polished with a polishing pad together with a polishing composition for semiconductor processing supplied from a spray nozzle, while the polishing head that fixes the substrate rotates and the platen to which the polishing pad is attached also rotates.

[0098] The process of polishing a substrate can optionally further include conditioning the surface of the polishing pad prior to polishing.

[0099] The polishing composition for semiconductor processing can polish a wafer in contact with the polishing pad while penetrating toward the substrate.

[0100] In the process of polishing the substrate, a pressure of 6.89 kPa to 48.26 kPa may be applied, and the pressure may be 13.79 kPa to 34.47 kPa.

[0101] The process of polishing the substrate may be carried out for 50 seconds to 10 minutes, although this can be varied depending on the desired degree of polishing.

[0102] The description of the polishing composition for semiconductor processing is omitted since it is the same as that described above.

[0103] The method for manufacturing a substrate may further include a cleaning process for cleaning the substrate after polishing.

[0104] The cleaning process may be performed by cleaning the polished substrate with purified water and an inert gas.

[0105] The present invention will be described in more detail with reference to specific examples below. The following examples are merely illustrative to aid in understanding the present invention, and are not intended to limit the scope of the present invention.

[0106] Production Example: Production of Polishing Composition For each of the examples and comparative examples, a polishing composition was prepared by mixing ultrapure water as a solvent with approximately 5 wt% colloidal silica surface-modified with 150 ppm (by weight) of (3-aminopropyl)triethoxysilane as abrasive particles, 2 wt% sorbitol, 0.001 wt% to 0.005 wt% 1,2-benzisothiazol-3(2H)-one, and the metal ions listed in Table 1 below, totaling 100 wt%.

[0107] The content of abrasive particles, the average particle size of the abrasive particles, and the content of each metal ion in the polishing composition of each Example and Comparative Example are shown in the following Table 1. The content of metal ions shown in Table 1 corresponds to the content of each metal ion in the polishing composition measured by ICP (Inductively Coupled Plasma).

[0108] The pH, zeta potential, electrical conductivity, and viscosity at 25° C. measured for the polishing compositions of each of the Examples and Comparative Examples are shown in Table 2 below.

[0109] Evaluation example: Measurement and evaluation of polishing characteristics The polishing composition was applied to polish the top surface of a 300 mm diameter wafer on a CTS AP-300 polisher.

[0110] The 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.

[0111] The wafer used included a tungsten pattern with a pattern density of 50% and a silicon oxide film.

[0112] After polishing, 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 of the polishing composition and the polishing selectivity of the silicon oxide film to the tungsten film were calculated.

[0113] In addition, in accordance with ISO 4287, the Ra value of the tungsten film on the substrate surface after polishing was measured by AFM (Atomic Force Microscopy).

[0114] The measured values ​​for the Examples and Comparative Examples are shown in Table 3 below.

[0115] JPEG2025077018000001.jpg228164

[0116] JPEG2025077018000002.jpg41137

[0117] JPEG2025077018000003.jpg62123

[0118] In Table 3, the Ra values ​​of the tungsten films of Examples 1 to 4 were measured to be 0.8 nm or less, whereas the Ra values ​​of the tungsten films of Comparative Examples 1 and 2 were measured to be over 1 nm. This means that Examples 1 to 4, in which the metal ion content is adjusted within a preset range in the embodiment, can provide a smoother polished surface than the Comparative Examples.

[0119] The polishing rates of silicon oxide films in Examples 1 to 4 were higher than that in Comparative Example 1. This means that when the first metal ion is contained in an excessive amount in the polishing composition, the polishing properties of the polishing composition for silicon oxide films are reduced.

[0120] In terms of the polishing rate of the tungsten film, Comparative Example 2 showed a significantly lower value than Examples 1 to 4. This means that the second metal ions contribute to improving the polishing properties of the polishing composition for the tungsten film.

[0121] Although the preferred embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concepts of the embodiments defined in the appended claims also fall within the scope of the present invention.

Claims

1. abrasive particles; and a first metal ion, the first metal ion being an alkali metal ion; the abrasive particles exhibit a positive surface charge; The content of the first metal ion in the polishing composition for semiconductor processing is 15 ppm (by weight) to 100 ppm (by weight).

2. a second metal ion selected from the group consisting of an iron ion, a copper ion, a nickel ion, an aluminum ion, a calcium ion, a zinc ion, and combinations thereof; 2. The polishing composition for semiconductor processing according to claim 1, wherein the ratio of the content (by weight) of the first metal ion to the content (by weight) of the second metal ion is 15 or more.

3. 2. The polishing composition for semiconductor processing according to claim 1, wherein the abrasive particles have a zeta potential of +10 mV to +50 mV at pH 2 to 5.

5.

4. The polishing composition for semiconductor processing according to claim 1 , wherein the abrasive particles are surface-modified with a compound having an amine group.

5. 2. The polishing composition for semiconductor processing according to claim 1, comprising 1% by weight to 10% by weight of the abrasive particles.

6. 2. The polishing composition for semiconductor processing according to claim 1, having an electrical conductivity of 10 μS / cm to 300 μS / cm.

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, having a viscosity at 25° C. of 0.8 cP to 2.0 cP.

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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