Polishing Composition for Semiconductor Processes and Substrate Polishing Method Using the Same

Abstract

To provide a polishing composition for semiconductor processes that can effectively suppress the formation of abrasive particle-derived defects on the surface of a substrate to be polished when applied to a chemical mechanical polishing (CMP) process, and that exhibits stable polishing characteristics.SOLUTION: A polishing composition for semiconductor process contains abrasive particles, and the Ds value of the abrasive particles according to the following formula 1 is 700 nm2 to 1400 nm2. [Formula 1] Ds=MPS2-D102. In formula 1, MPS is the mean particle size (mean particle size) of the primary abrasive particles. D10 is the particle size at the 10% point in the cumulative size distribution curve of the primary abrasive particles.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

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

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

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

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0006] The object of the embodiment is to provide a polishing composition for semiconductor processes that can effectively suppress the formation of defects derived from polishing particles on the surface of a substrate to be polished when applied to a CMP process and exhibits stable polishing characteristics.

Means for Solving the Problems

[0007] The polishing composition for semiconductor processes according to an embodiment of the present specification contains polishing particles.

[0008] The Ds value of the polishing particles according to the following formula 1 is 700 nm 2 ~1400 nm 2 is.

[0009] [Formula 1] Ds = MPS 2 -D 10 2

[0010] In the formula 1, the MPS is the average particle size of the primary particles of the polishing particles.

[0011] The D 10 is the particle size at the point where it becomes 10% in the cumulative curve of the particle size distribution of the primary particles of the polishing particles.

[0012] The polishing composition for semiconductor processes may have a Db value according to the following formula 2 of 500 nm 2 ~850 nm 2 is.

[0013] [Formula 2] Db = D 90 2 -D 50 2

[0014] In the formula 2, the D 90 is the particle size at the point where it becomes 90% in the cumulative curve of the particle size distribution of the primary particles of the polishing particles.

[0015] The D 50It is the particle size at the point where it becomes 50% in the cumulative curve of the particle size distribution of the primary particles of the abrasive particles.

[0016] The MPS value may be 25 nm or more and 55 nm or less.

[0017] The abrasive particles may be concentrated and purified by an ultrafiltration filter.

[0018] The ultrafiltration filter can include voids.

[0019] The voids can have a diameter of 5 nm to 25 nm.

[0020] The zeta potential of the polishing composition for semiconductor processes may be +10 mV to +40 mV.

[0021] The polishing composition for semiconductor processes can contain 0.5% by weight to 10% by weight of the abrasive particles.

[0022] The abrasive particles can include metal oxide particles.

[0023] The metal oxide particles can include at least one of colloidal silica, fumed silica, ceria, alumina, titania, and zirconia.

[0024] The polishing composition for semiconductor processes may have a pH of 2 to 5.

[0025] The method for manufacturing a substrate according to another embodiment of the present specification includes a process of applying the polishing composition for semiconductor processes as a slurry to polish the substrate.

Advantages of the Invention

[0026] When the polishing composition for semiconductor processes according to the embodiment is applied to a CMP process, it can effectively suppress the formation of defects derived from abrasive particles on the surface of the substrate to be polished, and can exhibit stable polishing characteristics.

BEST MODE FOR CARRYING OUT THE INVENTION

[0027] Hereinafter, the embodiments will be described in detail so that those having ordinary knowledge in the technical field to which the embodiments belong can easily implement them. However, the embodiments can be realized in various different forms and are not limited to the embodiments described herein.

[0028] As used herein, terms such as "about" and "substantially" are used in the sense of that numerical value or close to that numerical value when manufacturing and material tolerances inherent in the meaning being referred to are presented, and are used to prevent unscrupulous infringers from improperly using the disclosure where exact or absolute numerical values are referred to in order to aid in the understanding of the embodiments.

[0029] Throughout this specification, the term "these combinations" included in the Markush-form expression means one or more mixtures or combinations selected from the group consisting of the components described in the Markush-form expression, and means including one or more selected from the group consisting of the said components.

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

[0031] Throughout this specification, terms such as "first", "second" or "A", "B" are used to distinguish the same terms from each other unless otherwise specified.

[0032] As used herein, the meaning that B is located on A means that B can be located on A, or B can be located on A while another layer is located between them, and is not construed as being limited to the case where B is located in contact with the surface of A.

[0033] As used herein, singular expressions are construed to include the singular or plural as construed in the context unless otherwise specified.

[0034] The inventors of the embodiment experimentally confirmed that by controlling parameters related to the particle size distribution of abrasive particles, such as the Ds value, when applied to the CMP process, it is possible to effectively suppress the generation of defects derived from the abrasive particles on the surface of the substrate to be polished, while achieving a polishing composition for semiconductor processes that exhibits excellent polishing characteristics, and completed the embodiment.

[0035] Hereinafter, the embodiment will be specifically described.

[0036] Particle size distribution of abrasive particles The polishing composition for semiconductor processes according to the embodiment contains abrasive particles.

[0037] The Ds value of the abrasive particles according to the following formula 1 is 700 nm 2 ~1400 nm 2 .

[0038] [Formula 1] Ds = MPS 2 -D 10 2

[0039] In the formula 1, the MPS is the average particle size of the primary particles of the abrasive particles.

[0040] The D 10 is the particle size at the point where it becomes 10% in the cumulative curve of the particle size distribution of the primary particles of the abrasive particles.

[0041] When polishing the surface of a wafer or the like using a slurry for CMP, defects due to abrasive particles can be formed on the surface to be polished. Defects can be formed not only by scratches caused by abrasive particles having a relatively large size, but also by abrasive particles having a relatively small size. Abrasive particles having a relatively small size have a high surface energy and thus can strongly adsorb to the surface to be polished. In addition, since the adsorbed particles have the property of easily binding to organic substances, it may cause a problem that organic substances remain on the wafer surface. Such abrasive particles are not easily removed even by a cleaning process.

[0042] In the embodiment, by controlling the Ds value of the abrasive particles, the generation of defects on the surface to be polished can be effectively suppressed. In such a case, since the number of abrasive particles having a diameter small enough to easily adsorb to the surface to be polished in the abrasive particles can be controlled within a range preset in the embodiment, the generation of defects on the wafer surface can be effectively suppressed.

[0043] The MPS value and D of the abrasive particles 10 value are measured by the DLS (Dynamic Light Scattering) method using a particle size measuring device. Exemplarily, the values can be measured using Nano-ZS equipment of Malvern.

[0044] The measured MPS value and D 10 value are used to calculate the Ds value.

[0045] The Ds value of the abrasive particles can be 700 nm 2 ~1400 nm 2 It may be. The Ds value may be 800 nm 2 or more. The Ds value may be 900 nm 2 or more. The Ds value may be 1000 nm 2 or more. The Ds value may be 1100 nm 2 or more. The Ds value may be 1200 nm 2 or more. The Ds value may be 1380 nm 2It may be as follows. The Ds value is 1370 nm 2 It may be as follows. When applying such a polishing composition to a CMP process, it is possible to effectively suppress the generation of defects on the wafer surface due to the adsorption of polishing particles.

[0046] The Db value of the polishing particles according to the following formula 2 is 500 nm 2 ~830 nm 2 It may be.

[0047] [Formula 2] Db = D 90 2 - D 50 2

[0048] In the formula 2, the D 90 is the particle size at the point where it becomes 90% in the cumulative curve of the particle size distribution of the primary particles of the polishing particles.

[0049] The D 50 is the particle size at the point where it becomes 50% in the cumulative curve of the particle size distribution of the primary particles of the polishing particles.

[0050] Embodiments can control the Db value of the polishing particles. Through this, it is possible to effectively reduce the frequency of defects such as scratches by the polishing particles on the substrate to be polished during the CMP process.

[0051] The D 90 value and D 50 value are measured by the DLS (dynamic light scattering) method using a particle size measuring device. Exemplarily, the values can be measured using the Nano-ZS equipment of Malvern.

[0052] The measured D 90 value and D 50 value are used to calculate the Db value.

[0053] The Db value of the polishing particles is 500 nm 2 ~850 nm 2It can be. The Db value is 600 nm 2 or more. The Db value may be 650 nm 2 or more. The Db value may be 700 nm 2 or more. The Db value may be 750 nm 2 or more. The Db value may be 820 nm 2 or less. The Db value may be 800 nm 2 or less. In such a case, by controlling the number of abrasive grains having an excessively large diameter, the frequency of scratches occurring on the surface of the object to be polished can be effectively reduced.

[0054] The MPS value of the abrasive grains can be 25 nm to 55 nm. The MPS value may be 50 nm or less. The MPS value may be 45 nm or less. The MPS value may be 43.5 nm or less. The MPS value may be 30 nm or more. The MPS value may be 35 nm or more. The MPS value may be 40 nm or more.

[0055] The D of the abrasive grains 50 value can be 35 nm to 51 nm. The D 50 value may be 38 nm or more. The D 50 value may be 40 nm or more. The D 50 value may be 42 nm or more. The D 50 value may be 50 nm or less.

[0056] The D of the abrasive grains 90 value can be 45 nm to 56 nm. The D 90 value may be 48 nm or more. The D 90 value may be 50 nm or more.

[0057] When applying such a polishing composition to a CMP process, it can exhibit excellent polishing rate while reducing the degree of scratches formed on the surface of the polished object after polishing.

[0058] The D of the abrasive grains 10The value can be from 15 nm to 35 nm. The D 10 The value may be 18 nm or more. The D 10 The value may be 20 nm or more. The D 10 The value may be 22 nm or more. The D 10 The value may be 32 nm or less. The D 10 The value may be 30 nm or less. The D 10 The value may be 28 nm or less. In such a case, the frequency of the polishing particles adhering to the surface of the substrate during the CMP process can be reduced.

[0059] The polishing particles may be concentrated and purified by an ultrafiltration filter.

[0060] The ultrafiltration filter can include voids. The voids can have a diameter of 5 nm to 25 nm.

[0061] The description of concentrating and purifying the polishing particles by an ultrafiltration filter is omitted because it overlaps with the content described later.

[0062] Composition of abrasive particles The polishing particles can include metal oxide particles. The metal oxide particles can include at least any one of colloidal silica, fumed silica, ceria, alumina, titania, and zirconia. Exemplarily, the metal oxide particles may be colloidal silica.

[0063] For controlling the affinity between the surface to be polished and the polishing particles and improving the polishing rate, etc., the polishing composition for semiconductor processes can include, as the polishing particles, surface-modified metal oxide particles. In particular, an embodiment can apply polishing particles including metal oxide particles surface-modified by a silane-based compound containing an amine group or a ureido group. Through this, while reducing the electrostatic repulsive force of the polishing particles against the silicon oxide film, it is possible to suppress the excessive adsorption of the polishing particles to the surface of the substrate.

[0064] The abrasive particles can include metal oxide particles surface-modified with an aminosilane. The abrasive particles can have metal oxide particles surface-modified with an aminosilane applied thereto. The aminosilane can be, by way of 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.

[0065] The abrasive particles can include metal oxide particles surface-modified with a ureidosilane. The abrasive particles can have metal oxide particles surface-modified with a ureidosilane applied thereto. The ureidosilane can be, by way of example, any one selected from the group consisting of 3-ureidotrimethoxysilane, 3-ureidotriethoxysilane, and combinations thereof.

[0066] The abrasive particles can contain 1 to 10 parts by weight of a silane-based compound having an amine group or a ureido group based on 100 parts by weight of the metal oxide particles. The abrasive particles can contain 3 to 8 parts by weight of a silane-based compound having an amine group or a ureido group based on 100 parts by weight of the metal oxide particles. In such a case, the polishing characteristics of the polishing composition with respect to the silicon oxide film can be effectively improved.

[0067] Composition and physical properties of polishing composition for semiconductor process The polishing composition for semiconductor processes can contain 0.5 wt% to 10 wt% of polishing particles. The polishing composition for semiconductor processes may contain 1 wt% or more of polishing particles. The polishing composition for semiconductor processes may contain 1.5 wt% or more of polishing particles. The polishing composition for semiconductor processes may contain 2 wt% or more of polishing particles. The polishing composition for semiconductor processes may contain 8 wt% or less of polishing particles. The polishing composition for semiconductor processes may contain 6 wt% or less of polishing particles. Such a polishing composition can help reduce the frequency of defect generation during the polishing process while the polishing particles are stably dispersed within the composition.

[0068] The polishing composition for semiconductor processes can further contain an additive. The additive is not limited as long as it is commonly applied in the CMP field. Exemplarily, the additive may be at least any one of a nonionic polymer, a chelating agent, an oxidizing agent, an acid component, a pH adjuster, a dispersant, a polishing rate improver, a polishing regulator, a polishing pad protector, and a preservative.

[0069] The polishing composition for semiconductor processes can further improve the dispersibility of the polishing particles within the polishing composition by further containing a nonionic polymer. Specifically, the nonionic polymer contained in the polishing composition can be adsorbed onto the polishing particles to increase the dispersibility of the polishing particles. Also, the nonionic polymer that is not adsorbed onto the polishing particles has a steric hindrance effect, etc., so the dispersion stability of the polishing particles can be further enhanced. In particular, the nonionic polymer enables the polishing composition for semiconductor processes to have more stable dispersion stability even in an acidic environment. Such a nonionic polymer can reduce the occurrence of defects due to polishing on the substrate during the polishing process.

[0070] The nonionic polymer may be at least any one selected from the group consisting of polyethylene glycol, polypropylene glycol, polyvinylpyrrolidone, polyethylene oxide, polypropylene oxide, polyalkyl oxide, polyoxyethylene oxide, polyethylene oxide-propylene oxide copolymer, cellulose, methylcellulose, methylhydroxyethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, carboxymethylcellulose, carboxymethylhydroxyethylcellulose, sulfoethylcellulose, and carboxymethylsulfethylcellulose.

[0071] The nonionic polymer may have a weight average molecular weight of less than 25,000 g / mol. The weight average molecular weight may be 1,000 g / mol or more and less than 25,000 g / mol. In such a case, the nonionic polymer can exhibit excellent solubility and further improve the dispersion stability of the abrasive particles.

[0072] The polishing composition for semiconductor processes may contain 0.01% to 5% by weight of the nonionic polymer. The polishing composition for semiconductor processes may contain 0.1% by weight or more of the nonionic polymer. The polishing composition for semiconductor processes may contain 2% by weight or less of the nonionic polymer. In such a case, it can help reduce the frequency of defects occurring on the surface of the substrate to be polished after polishing and can suppress the occurrence of contamination such as reattachment of particles to the surface.

[0073] The polishing composition for semiconductor processes can further contain a chelating agent. Metals or metal ions removed from the surface of the substrate during the polishing process are likely to reattach or remain on the surface of the substrate and form defects. In particular, metals such as tungsten can be easily dissolved in the polishing composition under specific conditions, but may have the property of easily adhering to the surface of the object to be polished. The chelating agent can be adsorbed to such metals or metal ions and can easily remove the metals and the like. Through this, the polishing rate of the polishing composition can be further increased, and the formation of defects on the substrate surface due to the reattachment of particles can be effectively suppressed.

[0074] Exemplarily, the chelating agent may be at least one selected from the group consisting of butyric acid, citric acid, tartaric acid, succinic acid, oxalic acid, acetic acid, adipic acid, capric acid, caproic acid, caprylic acid, carboxylic acid, glutaric acid, glutamic acid, glycolic acid, thioglycolic acid, formic acid, mandelic acid, fumaric acid, lactic acid, lauric acid, malic acid, maleic acid, malonic acid, myristic acid, palmitic acid, phthalic acid, isophthalic acid, terephthalic acid, citraconic acid, propionic acid, pyruvic acid, stearic acid, valeric acid, benzoic acid, phenylacetic acid, naphthoic acid, aspartic acid, amino acids, and ethylenediaminetetraacetic acid.

[0075] As the amino acid, glycine, α-alanine, β-alanine, L-aspartic acid, N-methylglycine (methylglycine), or a combination thereof may be applied.

[0076] The chelating agent may contain two or more carboxyl groups or alcohol groups in the molecule. As the chelating agent, two or more kinds of those containing two or more carboxyl groups or alcohol groups in the molecule can be applied. Specifically, the chelating agent can contain any one selected from the group consisting of EDTA (ethylenediaminetetraacetic acid), glycine, carboxylic acids, and combinations thereof. The carboxylic acids mean compounds containing at least one or two or more carboxyl groups in the molecule.

[0077] The polishing composition for semiconductor processes can contain 0.003 wt% to 0.5 wt% of a chelating agent. The polishing composition for semiconductor processes may contain 0.005 wt% or more of a chelating agent. The polishing composition for semiconductor processes may contain 0.3 wt% or less of a chelating agent. In such cases, the polishing rate of the polishing composition can be controlled at an appropriate level, and the frequency of occurrence of surface defects on the substrate can be reduced.

[0078] The polishing composition for semiconductor processes can further contain an oxidizing agent. The oxidizing agent creates an environment that can more easily planarize the surface of the substrate by oxidizing a metal such as tungsten, and plays a role in improving the polishing rate and the etching rate.

[0079] The oxidizing agent may be at least any one selected from the group consisting of hydrogen peroxide, urea hydrogen peroxide, urea, percarbonate, periodic acid, periodate, perchloric acid, perchlorate, perbromic acid, perbromate, perboric acid, perborate, permanganic acid, permanganate, persulfate, bromate, chlorate, chlorite, chromate, iodate, iodic acid, ammonium persulfate, benzoyl peroxide, calcium peroxide, barium peroxide, sodium peroxide, and urea peroxide.

[0080] The polishing composition for semiconductor processes can contain 0.01 wt% to 5 wt% of an oxidizing agent. In such cases, the composition can exhibit excellent polishing characteristics with respect to the metal, and can suppress the formation of an oxide film on the metal to be polished during the polishing process.

[0081] The polishing composition for semiconductor processes may be an acidic solution. Specifically, the pH of the polishing composition for semiconductor processes can be 2 to 5. The pH may be 3 or more. The pH may be 4.5 or less. In such cases, it is possible to prevent excessive corrosion of the metal components on the surface of the substrate to be polished and the polishing apparatus, and to maintain the polishing rate and quality at an excellent level.

[0082] The polishing composition for semiconductor processes may further contain an acid component. The acid component may be, for example, at least any one selected from the group consisting of hydrochloric acid, phosphoric acid, sulfuric acid, hydrofluoric acid, bromic acid, iodic acid, formic acid, malonic acid, maleic acid, oxalic acid, acetic acid, adipic acid, citric acid, propionic acid, fumaric acid, lactic acid, salicylic acid, pimelic acid, benzoic acid, succinic acid, phthalic acid, butyric acid, glutaric acid, glutamic acid, glycolic acid, aspartic acid, tartaric acid and salts thereof.

[0083] The polishing composition for semiconductor processes may further contain 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 hydrogen carbonate, sodium carbonate, imidazole and combinations thereof.

[0084] The polishing composition for semiconductor processes may further contain a dispersant.

[0085] The dispersant can prevent aggregation between polishing particles in the polishing composition and disperse them uniformly. The cationic dispersant can increase the zeta potential of the polishing composition positively, and the anionic dispersant can decrease the zeta potential of the polishing composition negatively.

[0086] The dispersant can contain anionic low molecules, cationic polymers, organic acids, etc.

[0087] The anionic low molecules of the dispersant may be one or more selected from oxalic acid, citric acid, polysulfonic acid, polyacrylic acid, polymethacrylic acid and combinations thereof.

[0088] 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.

[0089] 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.

[0090] The polishing rate improver is an additive for increasing the polishing rate of the substrate or wiring to be polished, and may be one or more selected from potassium nitrate, iron nitrate, ammonium hydroxide, citric acid, acetic acid, and combinations thereof.

[0091] The polishing regulator is for minimizing the adsorption of the polishing composition to the metal surface, and may include ammonium compounds, potassium nitrate, amino acids, salts thereof, and the like.

[0092] The polishing composition for semiconductor processes may contain a solvent. The solvent may be water, specifically ultrapure water.

[0093] The zeta potential of the polishing composition for semiconductor processes can be +10 mV to +40 mV. The value of the zeta potential may be +20 mV or more. The value of the zeta potential may be +22 mV or more. The value of the zeta potential may be +35 mV or less. The value of the zeta potential may be +26 mV or less. In such cases, by controlling the affinity of the polishing composition for the surface of the substrate to be polished, it is possible to provide a polishing composition in which the degree of adsorption of polishing particles to the surface to be polished is controlled below a certain level while exhibiting excellent polishing characteristics.

[0094] The value of the zeta potential of the polishing composition is measured through a zeta potential measuring instrument.

[0095] Polishing characteristics of polishing composition for semiconductor process The polishing composition for semiconductor processes may be applied to the polishing of silicon oxide films. The polishing composition for semiconductor processes may be applied to the polishing of a substrate surface on which a silicon oxide film and wiring of a tungsten material are exposed. The polishing composition for semiconductor processes may be applied to the polishing of a substrate surface on which a silicon oxide film, wiring of a tungsten material, and a layer of a titanium material are exposed.

[0096] The polishing rate of the polishing composition for semiconductor processes with respect to the silicon oxide film may be 1350 Å / min or more. The polishing rate may be 1450 Å / min or more. The polishing rate may be 1550 Å / min or more. The polishing rate may be 1650 Å / min or more. The polishing rate may be 3500 Å / min or less. The polishing rate may be 3000 Å / min or less. The polishing rate may be 2500 Å / min or less.

[0097] The polishing rate with respect to the silicon oxide film is measured under the conditions of a pressure of 2.2 psi, a carrier speed of 103 rpm, a platen speed of 57 rpm, and a slurry flow rate of 300 ml / min.

[0098] The PI of the polishing composition for semiconductor processes according to the following formula 3 S value may be 380 Å / (min·wt%) to 800 Å / (min·wt%).

[0099] [Formula 3] JPEG0007709503000001.jpg1625

[0100] In the formula 3, the P S is the polishing rate [unit: Å / min] of the polishing composition for semiconductor processes with respect to the silicon oxide film.

[0101] The C is the content [unit: wt%] of polishing particles in the polishing composition for semiconductor processes.

[0102] The PI SThe value may be 400 Å / (min·wt%) or more. The PI S The value may be 450 Å / (min·wt%) or more. The PI S The value may be 500 Å / (min·wt%) or more. The PI S The value may be 550 Å / (min·wt%) or more. The PI S The value may be 700 Å / (min·wt%) or less. The PI S The value may be 600 Å / (min·wt%) or less.

[0103] Such a polishing composition can exhibit stable polishing characteristics with respect to a silicon oxide film.

[0104] The polishing rate of the polishing composition for semiconductor processes with respect to tungsten may be 150 Å / min or more. The polishing rate may be 180 Å / min or more. The polishing rate may be 200 Å / min or more. The polishing rate may be 250 Å / min or more. The polishing rate may be 400 Å / min or less.

[0105] The polishing rate with respect to tungsten is measured under the conditions of a pressure of 2.2 psi, a carrier speed of 63 rpm, a platen speed of 57 rpm, and a slurry flow rate of 300 ml / min.

[0106] The PI of the polishing composition for semiconductor processes according to the following formula 4 W The value may be 45 Å / (min·wt%) to 100 Å / (min·wt%).

[0107] [Formula 4] JPEG0007709503000002.jpg1729

[0108] In the formula 4, the P W is the polishing rate [unit: Å / min] of the polishing composition for semiconductor processes with respect to tungsten.

[0109] The C is the content [unit: wt%] of the polishing particles in the polishing composition for semiconductor processes.

[0110] The above PI W value may be 50 Å / (min·wt%) or more. The above PI W value may be 55 Å / (min·wt%) or more. The above PI W value may be 60 Å / (min·wt%) or more. The above PI W value may be 90 Å / (min·wt%) or less. The above PI W value may be 80 Å / (min·wt%) or less. The above PI W value may be 75 Å / (min·wt%) or less.

[0111] When such a polishing composition is applied to the polishing of tungsten, excellent polishing characteristics can be exhibited while suppressing the generation of excessive defects on the substrate surface.

[0112] Manufacturing method of polishing composition for semiconductor process The method for manufacturing a polishing composition for a semiconductor process according to an embodiment includes a particle size distribution control step of controlling the particle size distribution of polishing particles before purification to provide polishing particles after purification, and a manufacturing step of providing a polishing composition for a semiconductor process including the polishing particles after purification.

[0113] In the particle size distribution control step, at least a part of the polishing particles having a diameter below a certain level can be precisely removed to provide polishing particles with a controlled particle size distribution. Through this, it is possible to more effectively suppress small-diameter polishing particles that do not substantially participate in polishing from being adsorbed on the substrate surface and forming defects.

[0114] As a method for removing polishing particles having a diameter below a certain level from the polishing particles, a purification process using a filter, a centrifugation process, etc. can be applied.

[0115] The abrasive particles may be concentrated and purified by a filter having voids. Specifically, after mixing the abrasive particles with a solvent to form a mixture, the abrasive particles and the solvent having a diameter smaller than the voids contained in the mixture are allowed to pass through the filter, whereby the mixture can be concentrated and purified. Through this, abrasive particles having a size smaller than the voids can be effectively removed, and the frequency of occurrence of defects on the substrate surface derived from the abrasive particles can be reduced.

[0116] The filter can have any one of the forms of hollow fiber, flat plate, and tube. In particular, in the embodiment, a filter in the form of hollow fiber can be applied.

[0117] The filter may be an ultra-filtration filter. An ultrafiltration membrane is a separation membrane containing voids having a diameter of 1 nm to 50 nm.

[0118] The voids of the ultrafiltration filter can have a diameter of 5 nm to 25 nm. The diameter may be 10 nm or more. The diameter may be 20 nm or less.

[0119] The molecular weight cut-off (MWCO) of the ultrafiltration filter can be 300 Dalton to 300,000 daltons. The molecular weight cut-off may be 1,000 Dalton or more. The molecular weight cut-off may be 10,000 Dalton or more. The molecular weight cut-off may be 50,000 Dalton or more. The molecular weight cut-off may be 100,000 Dalton or more. The molecular weight cut-off may be 150,000 Dalton or more. The molecular weight cut-off may be 280,000 Dalton or less. The molecular weight cut-off is the minimum molecular weight of a solute that exhibits an exclusion degree of 90% or more by the separation membrane.

[0120] In such a case, a significant number of abrasive particles having characteristics that easily remain on the substrate surface can be effectively removed.

[0121] The ultrafiltration filter is not limited as long as it is commonly used in the field of ultrafiltration filters. Exemplarily, the ultrafiltration filter may be at least any one of a polyacrylonitrile separation membrane, a polyvinylidene fluoride separation membrane, a polysulfone separation membrane, a polyethersulfone separation membrane, a cellulose acetate separation membrane, a cellulose nitrate separation membrane, and a filter made of a copolymer material thereof.

[0122] The purification of the abrasive particles by the ultrafiltration filter may be performed once or multiple times. In particular, when the purification of the abrasive particles by the ultrafiltration filter is performed multiple times, the number of defects generated on the surface of the substrate to be polished can be further effectively reduced.

[0123] In such a case, it may be easy to control the particle size distribution of the abrasive particles within a range preset in the embodiment. At the same time, foreign substances such as suspended substances and polymer substances contained together with the abrasive particles, various bacteria, and viruses can be effectively removed.

[0124] By the centrifugation step, the abrasive particles before purification can be purified to provide abrasive particles after purification. The centrifugation step can be performed at a speed of 5000 rpm to 30000 rpm. The speed may be 25000 rpm or less. The speed may be 20000 rpm or less. The speed may be 15000 rpm or less. The speed may be 12000 rpm or less. The speed may be 8000 rpm or less. Through this, the particle size distribution of the purified abrasive particles can be effectively adjusted.

[0125] The purification of the abrasive particles by the centrifugation step may be performed once or multiple times.

[0126] The particle size distribution control step may be performed before the abrasive particles before purification are mixed with the additive in the solvent. The purification step of the abrasive particles may be performed in a state where the abrasive particles are mixed with the additive in the solvent.

[0127] Descriptions of the particle size distribution, composition, and physical properties of the polished particles after purification are omitted because they overlap with the above-mentioned content.

[0128] In the manufacturing step, the polishing composition for semiconductor processes can include polished particles after purification and a solvent. The polishing composition for semiconductor processes can further include an additive together with the polished particles after purification and the solvent.

[0129] Descriptions of the content of the polished particles after purification, the type of solvent, the type and content of the additive in the polishing composition for semiconductor processes are omitted because they overlap with the above-mentioned content.

[0130] In the particle size distribution control step, if the polished particles before purification are not mixed with the additive in the solvent, the polished particles after purification and the additive can be introduced and mixed into the solvent in the manufacturing step to provide a polishing composition for semiconductor processes. As a method for introducing and mixing the polished particles and the additive into the solvent, a method commonly applied in the CMP field can be applied.

[0131] Manufacturing method of substrate The method for manufacturing the substrate of the embodiment includes a process of polishing the substrate by applying the polishing composition for semiconductor processes as a slurry.

[0132] The substrate can include at least any one of an insulating film, a metal wiring, and a barrier layer on its upper surface. The metal wiring can include copper or tungsten. When the metal wiring includes copper, the barrier layer can include tantalum and its nitride. When the metal wiring includes tungsten, the barrier layer can include titanium and its nitride.

[0133] Specifically, in the process of polishing the substrate, the substrate to be polished is brought into contact with the polishing composition for semiconductor processes supplied from an injection nozzle on a polishing pad, while the polishing head that fixes the substrate rotates and the surface plate with the polishing pad attached also rotates.

[0134] The process of polishing the substrate may further include, if necessary, a step of conditioning the surface of the polishing pad before polishing.

[0135] The polishing composition for semiconductor processes can polish the wafer in contact with the polishing pad while penetrating toward the substrate.

[0136] In the process of polishing the substrate, a pressure of 6.89 kPa to 48.26 kPa can be applied. The pressure may be 13.79 kPa to 34.47 kPa.

[0137] The process of polishing the substrate can be carried out for 50 seconds to 10 minutes. However, it can be changed according to the desired degree of polishing.

[0138] The description of the polishing composition for semiconductor processes is omitted because it overlaps with the above content.

[0139] The method for manufacturing a substrate can further include a cleaning process of cleaning the polished substrate.

[0140] The cleaning process can be carried out by cleaning the polished substrate through purified water and an inert gas.

[0141] Hereinafter, specific examples will be described in more detail. The following examples are merely illustrative for helping the understanding of the present invention, and the scope of the present invention is not limited thereto.

[0142] Production Example: Production of Polishing Composition Example 1: Colloidal silica was prepared as the polishing particles before purification. The polishing particles before purification were surface-modified with (3-aminopropyl)triethoxysilane (99%, Sigma-Aldrich), which is an aminosilane. The D 50 of the surface-modified polishing particles before purification was measured to be 44 nm to 46 nm.

[0143] Thereafter, the surface-modified abrasive particles were put into ultrapure water to prepare a mixture containing 5% by weight of the abrasive particles before purification. The mixture was subjected to a purification step of being concentrated once using a UF filter (MWCO: 200,000 Dalton) from SYNOPEX to obtain the abrasive particles after purification. The concentration was carried out until the content of the abrasive particles before purification in the mixture reached 30% by weight.

[0144] Ultrapure water was charged with and mixed with the abrasive particles after purification, a polishing pad protector GC-30 from YUNWOO CHEMICAL to which 30% by weight of sorbitol was applied, and benzoisothiazolinone BNO-B-3 from BNOCHEM to produce a polishing composition. In the case of benzoisothiazolinone, a 3% by weight dilution solution using ultrapure water as a solvent was charged. The content of the abrasive particles after purification in the polishing composition was applied at 3% by weight, the content of sorbitol was 2% by weight, and the content of benzoisothiazolinone was 0.01% by weight. The zeta potential of the polishing composition was measured to be +20 mV to +25 mV.

[0145] Example 2: A polishing composition was produced under the same conditions as in Example 1, except that the abrasive particles obtained by performing the purification step applied in Example 1 twice were used as the abrasive particles after purification.

[0146] Example 3: A polishing composition was produced under the same conditions as in Example 2, except that the content of the abrasive particles after purification in the polishing composition was applied at 5% by weight.

[0147] Comparative Example 1: A polishing composition was produced under the same conditions as in Example 1, except that the abrasive particles that had not undergone the purification step were applied to the polishing composition.

[0148] Comparative Example 2: A polishing composition was produced under the same conditions as in Comparative Example 1, except that the content of the abrasive particles in the polishing composition was applied at 5% by weight.

[0149] The process conditions for each of the examples and comparative examples are described in Table 1 below.

[0150] Evaluation Example: Measurement of the particle size distribution of the abrasive particles MPS, D of the abrasive particles in the polishing compositions for each of the examples and comparative examples 10 , D 50 and D 90 were measured using a Nano-ZS instrument from Malvern. Subsequently, the Ds value and Db value were calculated from the measured values.

[0151] The measured values and calculated values for each of the examples and comparative examples are shown in Table 2 below.

[0152] Evaluation Example: Measurement of Polishing Rate The polishing compositions for each of the examples and comparative examples were applied as slurries, and the polishing rates for a silicon oxide film with a thickness of 20,000 Å formed on a 300 mm diameter wafer were measured. The polishing rate for the silicon oxide film was measured under the conditions of a polishing time of 60 seconds, a pressure of 2.2 psi, a carrier speed of 103 rpm, a platen speed of 57 rpm, and a slurry flow rate of 300 ml / min.

[0153] Also, the polishing compositions for each of the examples and comparative examples were applied as slurries, and the polishing rates for a tungsten film with a thickness of 650 Å formed on a 300 mm diameter wafer were measured. The polishing rate for the tungsten film was measured under the conditions of a polishing time of 15 seconds, a pressure of 2.2 psi, a carrier speed of 63 rpm, a platen speed of 57 rpm, and a slurry flow rate of 300 ml / min.

[0154] The measured values for each of the examples and comparative examples are shown in Table 3 below.

[0155] Evaluation Example: Measurement of Defects on the Surface of the Substrate to be Polished The polishing compositions for each of the examples and comparative examples were applied as slurries, and the silicon oxide film and tungsten film formed on the wafer were polished respectively. The measurement conditions were applied in the same manner as those applied to the evaluation of the polishing rate above.

[0156] A cleaning process was performed on the polished silicon oxide film and tungsten film under the conditions of a brush rotation speed of 500 rpm and a chemical injection speed of 2000 cc / min. As the chemical, an aqueous ammonia solution and a diluted hydrofluoric acid solution product from SIC were applied.

[0157] After wafers that had completed the cleaning process for each of the examples and comparative examples were sealed in a wafer FOUP, the total number of defects formed on the upper surfaces of the silicon oxide film and the tungsten film was measured using AIT-XP+ equipment.

[0158] The measurement results for each of the examples and comparative examples are shown in Table 3 below.

[0159]

Table 1

[0160]

Table 2

[0161]

Table 3

[0162] In Table 3 above, the number of defects in the silicon oxide film measured in Examples 1 to 3 was measured to be less than 500, while the number of defects in the silicon oxide film measured in Comparative Examples 1 and 2 was measured to be 1000 or more.

[0163] Also, the number of defects in the tungsten film measured in Examples 1 to 3 was measured to be less than 50, while the number of defects in the tungsten film measured in Comparative Examples 1 and 2 was measured to be 100 or more.

[0164] The polishing rate for the silicon oxide film measured in Examples 1 to 3 was measured to have a higher value compared to Comparative Examples 1 and 2, and the polishing rate for the tungsten film measured in Examples 1 to 3 was measured to be a value close to the measured values of Comparative Examples 1 and 2. That is, Examples 1 to 3 showed stable polishing characteristics for both the silicon oxide film and the tungsten film.

[0165] Although the preferred embodiments have been described in detail above, the scope of the rights of the present invention is not limited thereto, and various modifications and improvements 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 rights of the present invention.

Claims

1. comprising abrasive particles, The Ds value of the abrasive particles according to the following formula 1 is 700 nm ２ to 1400 nm ２ and the Db value according to the following formula 2 is 500 nm2 to 850 nm2, a polishing composition for semiconductor processes. [Formula 1] Ds = MPS ２ -D １０ ２ [Formula 2] Db = D902 - D502 (In the above formula 1, the MPS is the average particle size (Mean particle size) of the primary particles of the abrasive particles, Said D １０ is the particle size at the point where it becomes 10% in the cumulative curve of the particle size distribution of the primary particles of the abrasive particles, In the above formula 2, the D90 is the particle size at the point where it becomes 90% in the cumulative curve of the particle size distribution of the primary particles of the abrasive particles, the D50 is the particle size at the point where it becomes 50% in the cumulative curve of the particle size distribution of the primary particles of the abrasive particles.)

2. The polishing composition for semiconductor processes according to claim 1, wherein the MPS value is 25 nm to 55 nm.

3. The polishing composition for semiconductor processes according to claim 1, wherein the abrasive particles are concentrated and purified by an ultra-filtration filter.

4. The ultra-filtration filter contains voids, The polishing composition for semiconductor processes according to claim 3, wherein the voids have a diameter of 5 nm to 25 nm.

5. The polishing composition for semiconductor processes according to claim 1, wherein the zeta potential is +10 mV to +40 mV.

6. The polishing composition for semiconductor processes according to claim 1, containing 0.5% to 10% by weight of the abrasive particles.

7. The abrasive particles contain metal oxide particles, The polishing composition for semiconductor processes according to claim 1, wherein the metal oxide particles contain at least one of colloidal silica, fumed silica, ceria, alumina, titania, and zirconia.

8. The polishing composition for semiconductor processes according to claim 1, wherein the pH is 2 to 5.

9. A method for manufacturing a substrate, comprising the process of polishing a substrate by applying the polishing composition for semiconductor processes according to claim 1 as a slurry.

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