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

Abstract

A polishing composition for a semiconductor process according to one embodiment of the present specification includes polishing particles and a first metal ion that is an alkali metal ion. The surfaces of the polishing particles are positively charged. The polishing composition for a semiconductor process has a first metal ion content of 15 ppm (by weight) to 100 ppm (by weight). This polishing composition can provide a surface to be polished having excellent dispersibility and having a defect number controlled below a predetermined level.

Description

Technical Field

[0001] The implementation example relates to a polishing composition for semiconductor process and a method for manufacturing a substrate using the same. Background Art

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

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

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

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1 Korean Patent No. 10-2082922

[0008] Patent Document 2 Korean Publication Patent No. 10-2002-0029158 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] An object of the implementation example is to provide a polishing composition for semiconductor process, which has excellent dispersibility and can realize a polished surface with the number of defects controlled below a predetermined level when applied to a CMP process.

[0011] Means used to solve problems

[0012] A polishing composition for a semiconductor process according to one embodiment of the present specification includes polishing particles and first metal ions which are alkali metal ions.

[0013] The polishing particles have positive charges on their surfaces.

[0014] In the polishing composition for semiconductor process, the first metal ion content is 15 ppm (by weight) to 100 ppm (by weight).

[0015] The polishing composition for semiconductor process may include a second metal ion, wherein the second metal ion is selected from any one of iron ion, copper ion, nickel ion, aluminum ion, calcium ion, zinc ion and a combination thereof.

[0016] The ratio of the first metal ion content (by weight) to the second metal ion content (by weight) of the polishing composition for semiconductor processes may be 15 or more.

[0017] The polishing particles may have a zeta potential of +10 mV to +50 mV under a pH condition of 2 to 5.5.

[0018] The polishing particles may be surface-modified by a compound having an amine group.

[0019] The polishing composition for semiconductor processes may include 1 wt % to 10 wt % of the polishing particles.

[0020] The electrical conductivity of the polishing composition for semiconductor process may be 10 μS / cm to 300 μS / cm.

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

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

[0023] The polishing composition for semiconductor processes may have a viscosity of 0.8 cP to 2.0 cP at 25°C.

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

[0025] Effects of the Invention

[0026] The polishing composition for semiconductor process of the embodiment has excellent dispersibility and, when applied to a CMP process, can realize a polished surface with the number of defects controlled below a predetermined level. DETAILED DESCRIPTION

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

[0028] The terms of degree such as "approximately" and "substantially" used in this specification are intended to indicate that a numerical value is used or is close to the numerical value when the inherent manufacturing and material tolerances are proposed in the mentioned meaning, and are used to prevent unscrupulous infringers from improperly taking advantage of the disclosure that mentions exact or absolute values ​​to help understand the examples.

[0029] Throughout the present specification, the term "combination thereof" included in the Markush format expression means a mixture or combination of one or more selected from the group consisting of constituent elements described in the Markush format expression, and means including one or more selected from the group consisting of the constituent elements.

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

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

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

[0033] In this specification, unless otherwise specified, a singular expression is interpreted as including the singular or plural meaning explained in the context.

[0034] Hereinafter, a specific implementation example will be described.

[0035] Metal ions

[0036] In the polishing composition for semiconductor process according to the embodiment, in order to further improve the dispersibility of the polishing particles and the like, the first metal ions which are alkali metal ions and the polishing particles having positive charges on the surface may be used simultaneously.

[0037] Unlike other metal ions, alkali metal ions are not highly reactive in the polishing composition, so it is not easy to form metal oxides on the polished surface during the polishing process. When alkali metal ions are applied to the polishing composition, electrostatic repulsion is formed between the alkali metal ions and the polishing particles with positive charges on the surface, so that the dispersibility of the polishing composition can be improved by the alkali metal ions and the like.

[0038] Alkali metal ions are Group I elements and may include lithium, sodium, potassium, rubidium, cesium, and francium.

[0039] The first metal ion content of the polishing composition for semiconductor process may be 15ppm (by weight) to 100ppm (by weight). The first metal ion content may be 20ppm (by weight) or more. The first metal ion content may be 25ppm (by weight) or more. The first metal ion content may be 28ppm (by weight) or more. The first metal ion content may be 32ppm (by weight) or more. The first metal ion content may be 70ppm (by weight) or less. The first metal ion content may be 60ppm (by weight) or less. The first metal ion content may be 50ppm (by weight) or less. In this case, the dispersibility of the polishing particles can be effectively improved. At the same time, it is possible to suppress excessive adsorption of a large amount of the first metal ions on the polished surface, thereby deteriorating the electrical characteristics of the device, or excessively reducing the polishing characteristics of the polishing composition on the polished surface.

[0040] The polishing composition for semiconductor process may contain a second metal ion, wherein the second metal ion is any one selected from the group consisting of iron ion, copper ion, nickel ion, aluminum ion, calcium ion, zinc ion and a combination thereof.

[0041] 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.

[0042] Since the second metal ion has a relatively high reactivity, it can help adjust the polishing characteristics of the polishing composition for the inhibitor film. However, the metal ion is easy to react with other compounds during the polishing and cleaning process, so that it can easily form precipitates on the polished surface, and the metal ion can reduce the electrical characteristics of the device manufactured by adsorbing on the substrate surface. Implementation Example The frequency of defects formed on the substrate surface can be reduced to below a predetermined level by adjusting the ratio of the first metal ion content to the second metal ion content, and the dispersibility and polishing characteristics of the polishing composition can be effectively improved.

[0043] The ratio of the first metal ion content (by weight) to the second metal ion content (by weight) of 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 this case, the reduction in device yield due to the addition of metal ions can be stably suppressed.

[0044] 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 this case, the polishing characteristics of the tungsten film can be adjusted to an appropriate range while effectively suppressing the contamination of the polished surface caused by the metal ions.

[0045] The metal ion content of the polishing composition is measured by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES).

[0046] Polishing particles

[0047] The polishing composition can contain polishing particles.

[0048] The polishing particles may include metal oxide particles and / or silicon oxide particles. The polishing particles may include silicon dioxide. The polishing particles may include colloidal silicon dioxide.

[0049] The polishing particles may contain 70% or more of colloidal silica by weight. The polishing particles may contain 80% or more of colloidal silica by weight. The polishing particles may contain 90% or more of colloidal silica by weight. The polishing particles may be colloidal silica.

[0050] The polishing particles may have a positive charge on the surface. The polishing particles with a positive charge on the surface refer to polishing particles with a positive electromotive potential (zeta potential) in the polishing composition. Specifically, the polishing particles with a positive charge on the surface refer to polishing particles with a positive zeta potential under a pH of 2 to 5.5.

[0051] The polishing particles with positive surface charge can show excellent dispersibility due to the electrostatic interaction with the first metal ion. In addition, such particles can have the property of easily contacting the negatively charged surface of the silicon oxide film. Thus, the polishing particles can impart the polishing property of improving the silicon oxide film to the polishing composition.

[0052] The zeta potential of the polishing particles under the condition of pH 2 to 5.5 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 this case, due to the interaction with the first metal ions, the polishing particles may be easily dispersed, and the polishing composition may have an excellent polishing rate for the silicon oxide film.

[0053] The zeta potential of the polishing particles is measured by a particle size analyzer. For example, the particle size analyzer may be a Nano-ZS model from Malvern Instruments.

[0054] The polishing particles may be surface modified to have a positive charge on their surface. The polishing particles may be surface modified by a compound having an amine group. The surface modification of the polishing particles by a compound having an amine group is interpreted to include not only the surface modification of the polishing particles by a compound having an amine group only, but also the surface modification of the polishing particles by a compound having an amine group and another compound not having an amine group.

[0055] The polishing particles may be surface modified by a compound comprising an aminosilane. The polishing particles may be surface modified by an aminosilane.

[0056] For example, the aminosilane may be selected from 3-aminopropyltriethoxysilane, bis[(3-triethoxysilane)propyl]amine, 3-aminopropyltrimethoxysilane, bis[3-(trimethoxysilane)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilane)propyl]ethylenediamine, N-bis[3-(trimethoxysilane)propyl]-1,2- Any one of the group consisting of ethylenediamine, N-[3-(triethoxysilyl)propyl]ethylenediamine, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylaminomethyltriethoxysilane, diethylaminopropyltrimethoxysilane, diethylaminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane, N-[3-(trimethoxysilyl)propyl]n-butylamine, and combinations thereof.

[0057] The polishing composition for semiconductor process may contain 15ppm (by weight) to 200ppm (by weight) of aminosilane. The polishing composition for semiconductor process may contain 20ppm (by weight) or more of aminosilane. The polishing composition for semiconductor process may contain 25ppm (by weight) or more of aminosilane. The polishing composition for semiconductor process may contain 30ppm (by weight) or more of aminosilane. The polishing composition for semiconductor process may contain 150ppm (by weight) or less of aminosilane. The polishing composition for semiconductor process may contain 100ppm (by weight) or less of aminosilane. The polishing composition for semiconductor process may contain 70ppm (by weight) or less of aminosilane. The polishing composition for semiconductor process may contain 50ppm (by weight) or less of aminosilane. In this case, the electrostatic repulsion between the polishing particles and the first metal ions can be adjusted to an appropriate strength. At the same time, the polishing composition can have a further excellent polishing rate for silicon oxide film.

[0058] The polishing composition for semiconductor process may contain 1 wt % to 10 wt % of polishing particles. The polishing composition for semiconductor process may contain more than 2 wt % of polishing particles. The polishing composition for semiconductor process may contain less than 8 wt % of polishing particles. The polishing composition for semiconductor process may contain less than 5 wt % of polishing particles. In this case, the polishing composition has an excellent polishing rate to the polished surface, and can stably suppress the aggregation of the polishing particles.

[0059] The average particle size of the polishing particles may be 20 nm or more. The particle size may be 30 nm or more. The particle size may be 40 nm or more. The particle size may be 70 nm or less. The particle size may be 60 nm or less. The particle size may be 50 nm or less. In this case, the polishing composition exhibits an excellent polishing rate on the polished surface and can stably adjust the frequency of defects occurring on the polished surface.

[0060] The average particle size refers to the average particle size of primary particles of the polishing particles.

[0061] Physical properties of polishing compositions

[0062] The pH of the semiconductor process polishing composition 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 this case, the polishing particles have a relatively strong positive charge and can be more easily dispersed. In addition, the polishing composition can exhibit a polishing rate above a predetermined level for the silicon oxide film.

[0063] The pH of the polishing composition is measured with a pH meter.

[0064] The zeta potential of the polishing composition for semiconductor process may be from +10mV to +50mV. The zeta potential may be above +15mV. The zeta potential may be above +20mV. In this case, the frequency of scratches on the polished surface due to the aggregation of polishing particles or the adsorption of polishing particles to the polished surface can be effectively reduced.

[0065] 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 Instruments.

[0066] The conductivity of the polishing composition for semiconductor process may be 10 μS / cm to 300 μS / cm. The conductivity may be 20 μS / cm or more. The conductivity may be 30 μS / cm or more. The conductivity may be 40 μS / cm or more. The conductivity may be 50 μS / cm or more. The conductivity may be 200 μS / cm or less. The conductivity may be 150 μS / cm or less. The conductivity may be 120 μS / cm or less. In this case, the aggregation of polishing particles can be effectively suppressed by adjusting the amount of the first metal ions contained in the polishing composition, and the excessive corrosion of the metal wiring formed on the polished surface during the polishing process can be suppressed.

[0067] The viscosity of the polishing composition for semiconductor process 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 this case, the occurrence of defects such as scratches on the polished surface can be effectively suppressed by suppressing excessive aggregation between the components in the polishing composition.

[0068] The viscosity of the polishing composition is measured using a viscometer.

[0069] Composition of polishing composition

[0070] Fluorinated surfactants

[0071] The semiconductor process polishing composition of the embodiment may further include a fluorine surfactant. The surfactant is attached to the silicon oxide film, thereby effectively inhibiting the polishing particles with positive charges on the surface from being strongly adsorbed to the oxide film. In addition, the surfactant is attached to the organic particles, thereby helping the particles to be easily discharged.

[0072] The fluorine surfactant may be a fluoroalkyl epoxyalkyl compound. The fluorine surfactant may be a compound represented by the following Chemical Formula 1.

[0073] Chemical formula 1

[0074] R f -(R en -O) n -H

[0075] In the chemical formula 1, the R f is a fluoroalkyl group having 3 to 10 carbon atoms, wherein R en is an alkylene group having 2 or 3 carbon atoms, and n is an integer of 2 to 15.

[0076] In the chemical formula 1, R f The perfluoroalkyl group may be a group having 3 to 10 carbon atoms.

[0077] The fluorine surfactant may be a polymer surfactant. The weight average molecular weight of the fluorine surfactant may be 150 g / mol to 3000 g / mol. The weight average molecular weight may be 300 g / mol or more. The weight average molecular weight may be 500 g / mol or more. The weight average molecular weight may be 2500 g / mol or less. The weight average molecular weight may be 2000 g / mol or less. The weight average molecular weight may be 1500 g / mol or less.

[0078] The fluorine surfactant having the above-mentioned characteristics has a main chain length adjusted so that it can be effectively attached to the surface of the silicon oxide film. In addition, it is possible to prevent the dispersibility of the polishing composition from being excessively deteriorated due to the surfactant.

[0079] The weight average molecular weight of the polymer surfactant is measured by gel permeation chromatography (GPC).

[0080] In the implementation example, the content of the fluorine surfactant can be adjusted to a preset range, thereby preventing the polishing particles from adhering to the polished surface after polishing, and preventing the polishing composition from generating excessive foam during the polishing process, thereby preventing the processability from being reduced.

[0081] The polishing composition for semiconductor process may contain more than 10ppm (by weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 20ppm (by weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 50ppm (by weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 100ppm (by weight) of fluorine surfactant. The polishing composition for semiconductor process may contain more than 150ppm (by weight) of fluorine surfactant. The polishing composition for semiconductor process may contain less than 500ppm (by weight) of fluorine surfactant. The polishing composition for semiconductor process may contain less than 450ppm (by weight) of fluorine surfactant. In this case, the adsorption of polishing particles on the oxide film can be effectively suppressed, while suppressing the generation of excessive foam during the polishing process.

[0082] Other additives

[0083] The semiconductor process polishing composition may further include other additives. As long as they are conventional additives used in the CMP field, the additives are not limited. Exemplarily, the additives may be at least one of an oxidant, an acid component, a pH regulator, a chelating agent, a dispersant, a polishing rate enhancer, a polishing regulator, a polishing pad protector, and a preservative.

[0084] The polishing composition for semiconductor processing may further contain an oxidizing agent. The role of the oxidizing agent is to create an environment that can more easily planarize the substrate surface by oxidizing metal such as tungsten, and to increase the polishing rate and etching rate.

[0085] The oxidizing agent can be at least one selected from the group consisting of hydrogen peroxide, urea hydrogen peroxide, urea, percarbonate, periodic acid, periodate, perchloric acid, perchlorate, perbromic acid, perbromate, perboric acid, perborate, permanganic acid, permanganate, persulfate, bromate, chlorate, chlorite, chromate, iodate, iodic acid, ammonium persulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide and urea peroxide.

[0086] The polishing composition for semiconductor process may contain 0.01 wt % to 5 wt % of an oxidizing agent. In this case, the composition may exhibit excellent polishing characteristics for metals and may suppress the formation of an oxide film on the metal to be polished during polishing.

[0087] The polishing composition for semiconductor processing further comprises an acid component. For example, the acid component may be at least one selected from the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, bromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, adipic acid, acetic acid, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, lactic acid, aspartic acid, tartaric acid and salts thereof.

[0088] The polishing composition for semiconductor processing may further contain a pH adjuster together with the acid component. For example, the pH adjuster may be any one selected from the group consisting of ammonia, aminomethyl propanol, tetramethyl ammonium hydroxide, potassium hydroxide, sodium hydroxide, magnesium hydroxide, rubidium hydroxide, cesium hydroxide, sodium bicarbonate, sodium carbonate, and combinations thereof.

[0089] The polishing composition for semiconductor processing may contain a chelating agent. The chelating agent can prevent the polishing metal particles from being adsorbed on the polished surface.

[0090] The chelating agent may contain two or more carboxyl groups or alcohol groups in the molecule. As the chelating agent, two or more chelating agents containing two or more carboxyl groups or alcohol groups in the molecule may be used. Specifically, the chelating agent may contain any one selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), glycine, carboxylic acids, and combinations thereof. The carboxylic acids refer to compounds containing at least one or more carboxyl groups in the molecule.

[0091] The polishing composition for semiconductor processing may further comprise a dispersant.

[0092] The dispersant can prevent aggregation of polishing particles in the polishing composition and make them uniformly dispersed. Cationic dispersants can increase the zeta potential of the polishing composition to a positive (+) value, and anionic dispersants can reduce the zeta potential of the polishing composition to a negative (-) value.

[0093] Dispersants may include anionic small molecules, cationic macromolecules, organic acids, and the like.

[0094] The anionic small molecules of the dispersant may be one or more selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid and combinations thereof.

[0095] The cationic macromolecule of the dispersant can be one or more selected from polylysine, polyethyleneimine, benzethonium chloride, bromobenzylamine, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, dimethyldioctadecylammonium chloride, tetramethylammonium hydroxide, dioctadecyldimethylammonium chloride, polyarylamines and combinations thereof.

[0096] 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.

[0097] The polishing rate enhancer is an additive used to improve the polishing rate of the substrate or wiring to be polished, and can be one or more selected from potassium nitrate, ferric nitrate, ammonium hydroxide, citric acid, acetic acid and combinations thereof.

[0098] The polishing conditioner is used to minimize the adsorption of the polishing composition on the metal surface, and may include ammonium compounds, potassium nitrate, amino acids, salts thereof, and the like.

[0099] The polishing composition for semiconductor process may contain a solvent, which may be water, and specifically, ultrapure water.

[0100] Polishing properties of polishing compositions

[0101] The polishing rate of the semiconductor process polishing composition for silicon oxide film may be 950 / minute or more. The polishing rate may be 1000 / minute or more. The polishing rate may be 1100 / minute or more. The polishing rate may be 3000 / minute or less. The polishing rate may be 2500 / minute or less. The polishing rate may be 2000 / minute or less.

[0102] The polishing rate of the semiconductor process polishing composition for tungsten film can be 70 / min or more. The polishing rate can be 500 / min or less. The polishing rate can be 300 / min or less. The polishing rate can be 200 / min or less.

[0103] The polishing selectivity of the semiconductor process polishing composition to the tungsten film and the silicon oxide 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.

[0104] In this case, the polishing composition can show an excellent selectivity ratio of the silicon oxide film polishing rate compared to the tungsten polishing rate.

[0105] The Ra value of the tungsten film measured after polishing with the semiconductor process polishing composition 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. The polishing composition having the above characteristics can provide a tungsten film with reduced damage due to corrosion when used for polishing.

[0106] The Ra value is measured according to ISO 4287 by atomic force microscopy (AFM).

[0107] Each film was polished under the conditions of a pressure of 2.2 psi, a carrier speed of 87 rpm, a platen speed of 93 rpm, and a slurry flow rate of 250 ml / min. The polishing pad used was the SR-300 model of SK Enpulse Co., Ltd. of South Korea.

[0108] When the polishing rate of each thin film is measured, the polishing machine may be exemplarily an AP-300 model of CTS Corporation of Korea.

[0109] Method for manufacturing substrate

[0110] The method for manufacturing a substrate of the embodiment includes a process of polishing the substrate using the polishing composition for semiconductor process as slurry.

[0111] The substrate may include at least one of an insulating film, a metal wiring and a barrier layer on the upper surface. The metal wiring may include copper or tungsten. When the metal wiring includes copper, the barrier layer may include tantalum and its nitride. When the metal wiring includes tungsten, the barrier layer may include titanium and its nitride.

[0112] Specifically, the process of polishing the substrate can be performed as follows: the substrate to be polished is contacted on the polishing pad together with the semiconductor process polishing composition supplied from the nozzle, while the polishing head fixing the substrate rotates and the top plate attached with the polishing pad also rotates.

[0113] If necessary, the process of polishing the substrate may further include a process of adjusting the surface of the polishing pad before polishing.

[0114] The polishing composition for semiconductor processing can penetrate into the substrate and polish the wafer in contact with the polishing pad at the same time.

[0115] During polishing of the substrate, a pressure of 6.89 kPa to 48.26 kPa may be applied. The pressure may be 13.79 kPa to 34.47 kPa.

[0116] The process of polishing the substrate may be performed for 50 seconds to 10 minutes, but this may be varied depending on the desired polishing degree.

[0117] The description of the polishing composition for semiconductor process is omitted because it overlaps with the above contents.

[0118] The method for manufacturing a substrate may further include a cleaning process of cleaning the polished substrate.

[0119] The cleaning process may be performed by using pure water and an inert gas to clean the polished substrate.

[0120] The following examples are described in more detail. The following examples are only examples to help understand the present invention, and the scope of the present invention is not limited thereto.

[0121] Preparation Example: Preparation of polishing composition

[0122] For each of the Examples and Comparative Examples, approximately 5 wt % of colloidal silica surface-modified with 150 ppm (by weight) of (3-aminopropyl)triethoxysilane as polishing particles, 2 wt % of sorbitol, 0.001 wt % to 0.005 wt % of 1,2-benzisothiazolyl-3(2H)-one, and the metal ions listed in Table 1 below were mixed in ultrapure water as a solvent to prepare a polishing composition having a total of 100 wt %.

[0123] The polishing particle content, average particle size of the polishing particles, and each metal ion content of the polishing composition of each embodiment and comparative example are recorded in the following Table 1. The metal ion content recorded in Table 1 corresponds to each metal ion content of the polishing composition measured by inductively coupled plasma (ICP).

[0124] The pH, zeta potential, conductivity, and viscosity at 25° C. measured for the polishing compositions of the Examples and Comparative Examples are shown in Table 2 below.

[0125] Evaluation example: Polishing characteristics measurement and evaluation

[0126] The upper surface of a wafer having a diameter of 300 mm was polished using the polishing composition using an AP-300 polishing machine produced by CTS Corporation of Korea.

[0127] Polishing was performed under the conditions of a polishing time of 60 seconds, a pressure of 2.2 psi, a carrier speed of 93 rpm, a platen speed of 87 rpm, and a slurry flow rate of 300 ml / min.

[0128] The wafer is applied to include a tungsten pattern with a pattern density of 50% and a silicon oxide film.

[0129] After polishing was completed, the polishing rate of each film of the polishing composition and the polishing selectivity of the silicon oxide film to the tungsten film were calculated by measuring the difference in thickness of the silicon oxide film and the tungsten film before and after polishing.

[0130] Furthermore, according to ISO 4287, the Ra value of the tungsten film on the surface of the substrate after polishing was measured using an atomic force microscope (AFM).

[0131] The measured values ​​of each Example and Comparative Example are shown in Table 3 below.

[0132] Table 1

[0133]

[0134]

[0135] Table 2

[0136] Example 1 Example 2 Example 3 Example 4 Comparative Example 1 pH 4.19 4.14 4.21 4.18 4.05 Zeta potential (mV) 25.13 25.77 22.03 22.63 25.20 Conductivity (μS / cm) 59.38 66.04 33.52 35.60 618.50 Viscosity(cP) 1.024 1.027 1.036 1.074 1.033

[0137] Table 3

[0138]

[0139]

[0140] 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 more than 1 nm. This means that Examples 1 to 4, in which the metal ion content and the like were adjusted within the preset range of the examples, can provide smoother polished surfaces than the comparative examples.

[0141] In terms of the silicon oxide film polishing rate, Examples 1 to 4 show higher values ​​than Comparative Example 1. This means that when the first metal ion is excessively contained in the polishing composition, the polishing property of the polishing composition for the silicon oxide film is degraded.

[0142] In terms of the tungsten film polishing rate, Comparative Example 2 shows a significantly lower value compared with Examples 1 to 4. This means that the second metal ion contributes to improving the polishing characteristics of the polishing composition for a tungsten film.

[0143] The preferred embodiments are described in detail above, but the protection scope of the invention claimed by the present invention is not limited thereto. Various modifications and improvements made by ordinary technicians in the technical field to which the present invention belongs using the basic concepts of the implementation examples defined in the attached protection scope of the invention claims also fall within the protection scope of the claims of the present invention.

Claims

1. A polishing composition for semiconductor processing, wherein: comprising polishing particles and first metal ions which are alkali metal ions, The polishing particles have a positive charge on their surfaces. The first metal ion is contained in an amount of 15 ppm to 100 ppm by weight.

2. The semiconductor process polishing composition according to claim 1, wherein comprising a second metal ion, wherein the second metal ion is selected from any one consisting of iron ion, copper ion, nickel ion, aluminum ion, calcium ion, zinc ion and a combination thereof, A 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. The semiconductor process polishing composition according to claim 1, wherein The polishing particles have a zeta potential of +10 mV to +50 mV under a pH condition of 2 to 5.

5.

4. The semiconductor process polishing composition according to claim 1, wherein The polishing particles are surface-modified by a compound having an amine group.

5. The semiconductor process polishing composition according to claim 1, wherein The polishing particles are contained in an amount of 1 wt % to 10 wt %.

6. The semiconductor process polishing composition according to claim 1, wherein The conductivity is 10 μS / cm to 300 μS / cm.

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

8. The semiconductor process polishing composition according to claim 1, wherein The viscosity at 25°C is 0.8 cP to 2.0 cP.

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

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