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

Abstract

To provide a polishing composition for semiconductor process that can polish the surface of a substrate containing a fine pitch tungsten pattern film to a smooth surface.SOLUTION: A polishing composition for semiconductor process according to one example includes abrasive particles, iron ions, and iron ion stabilizers. The iron ion stabilizer contains two or more carboxyl groups. The polishing composition for semiconductor process has an electrical conductivity of 200 μS / cm to 800 μS / cm.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. 10-1293790 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 can smoothly polish a surface of a substrate including a fine-pitch tungsten pattern film. [Means for solving the problem]

[0007] A polishing composition for semiconductor processing according to one embodiment of the present specification includes abrasive particles, iron ions, and an iron ion stabilizer.

[0008] The iron ion stabilizer contains two or more carboxyl groups.

[0009] The polishing composition for semiconductor processing has an electrical conductivity of 200 μS / cm to 800 μS / cm.

[0010] The iron ion stabilizer may be any one selected from the group consisting of ethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, and combinations thereof.

[0011] The polishing composition for semiconductor processing may have a ratio of the content (weight basis) of the iron ion stabilizer to the content (weight basis) of the iron ions of 3 to 50.

[0012] The polishing composition for semiconductor processing contains iron ions in an amount of 1×10 -4 Weight%~5×10 -3 It may contain % by weight.

[0013] The polishing composition for semiconductor processing may further include a polyglycerin-based compound.

[0014] The polyglycerin compound may have a weight average molecular weight of 300 g / mol to 1,200 g / mol.

[0015] The polishing composition for semiconductor processing may contain the polyglycerin-based compound in an amount of 0.001% by weight to 0.1% by weight.

[0016] The polishing composition for semiconductor processing may have a polishing selectivity of 1-5 for a silicon oxide film to a tungsten film.

[0017] The polishing composition for semiconductor processing may have a pH of 1.5 to 4.5.

[0018] The polishing composition for semiconductor processing may have a number of particles having a diameter of more than 1 μm per unit volume as measured by a large particle counter (LPC) of 80 particles / ml or less.

[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 can polish the surface of a substrate including a fine-pitch tungsten pattern film to a smooth surface. BEST MODE FOR CARRYING OUT THEINVENTION

[0021] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention is not limited to the embodiments described herein, but may be practiced in various different forms.

[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] The term "compound based on -" includes the "compound based on -" and its derivatives. For example, the polyglycerin compound refers to a polyglycerin compound and a derivative of a polyglycerin compound.

[0029] The process of polishing the surface of the substrate including the tungsten pattern film may be performed in two steps: a first tungsten polishing process in which the tungsten bulk layer is polished to expose the tungsten pattern film and the insulating layer, and a second tungsten polishing process in which the step between the tungsten pattern film and the insulating layer is reduced.

[0030] As the pitch of the tungsten pattern film decreases, defects occur more frequently during the secondary tungsten polishing process. Specifically, defects such as an increase in the step of the contact pattern and misalignment with the upper contact pattern occur more frequently.

[0031] The polishing composition of the embodied examples can provide a polished surface that is smooth and has reduced defects even when polishing a surface of a substrate including a fine-pitch tungsten pattern film.

[0032] Hereinafter, the embodiment will be described in detail.

[0033] Composition of the polishing composition Iron ions and iron ion stabilizers The polishing composition for semiconductor processing according to the embodiment includes abrasive particles, iron ions, and an iron ion stabilizer.

[0034] The iron ions can be derived from compounds including iron ion complex compounds, hydrates of iron ion compounds and iron ion complex compounds as well as common iron ionic compounds.

[0035] The iron ions can promote the oxidation of tungsten during the polishing process of the tungsten pattern film. In addition, the iron ions can contribute to the polishing composition having a controlled zeta potential. Through this, the iron ions can prevent the polishing composition from overpolishing an insulating film, specifically a silicon oxide film. In addition, the polishing properties of the polishing composition for the tungsten film can be improved, and the occurrence of steps on the substrate after polishing due to overpolishing of the silicon oxide film can be suppressed.

[0036] The iron ions may be divalent iron ions or trivalent iron ions.

[0037] The iron ions may be, for example, those derived from iron chloride, iron nitrate, iron sulfate, iron perchlorate, iron acetate, iron citrate, Fe(III)-EDTA (Ethylenediaminetetraacetic Acid), etc., but are not limited thereto.

[0038] Meanwhile, in the polishing composition, iron ions can have a relatively high reactivity. Due to this characteristic, iron ions can be a reactant of a side reaction without participating in the reaction that oxidizes the tungsten film. The iron ion stabilizer can be useful for stabilizing iron ions in the polishing composition, so that more iron ions can be used in the polishing process of the tungsten film.

[0039] The iron ion stabilizer may include two or more carboxyl groups, which may form coordinate bonds with iron ions to adjust the reactivity of the iron ions in the polishing composition.

[0040] The iron ion stabilizing agent may be any one selected from the group consisting of ethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, and combinations thereof.The iron ion stabilizing agent may be any one selected from the group consisting of ethanedioic acid, propanedioic acid, butanedioic acid, and combinations thereof.

[0041] In the embodiment, the ratio of the content of the iron ion and the iron ion stabilizer may be adjusted within a predetermined range, thereby stabilizing a sufficient number of iron ion compounds in the polishing composition, and effectively improving the polishing properties of the polishing composition for a tungsten film.

[0042] In the polishing composition for semiconductor processing, the ratio of the content (by weight) of the iron ion stabilizer to the content (by weight) of iron ions may be 3 to 50. The ratio may be 5 or more. The ratio may be 10 or more. The ratio may be 14 or more. The ratio may be 40 or less. The ratio may be 30 or less. In such cases, the iron ion stabilizer can sufficiently control the reactivity of iron ions in the polishing composition, and can prevent the pH of the polishing composition from becoming excessively low due to the iron ion stabilizer.

[0043] The polishing compound for semiconductor processing contains iron ions at 1×10 -4 Weight%~5×10 -3 The polishing composition may contain 3×10 iron ions by weight. -4 The polishing composition may contain 5×10 iron ions or more by weight. -4 The polishing composition may contain 4×10 iron ions or more by weight. -3 The polishing composition may contain up to 3×10 iron ions by weight. -3% by weight or less. In this case, the polishing properties of the polishing composition for the tungsten film and the silicon oxide film can be adjusted. Thus, the surface of the substrate including the finely formed tungsten pattern film can be polished more smoothly.

[0044] The iron ion content of the polishing composition for semiconductor processing can be measured by ICP-OES (Inductively Coupled Plasma Optical Emission Spectroscopy).

[0045] Polyglycerol Compounds The polishing composition for semiconductor processing may further include a polyglycerin-based compound. The polyglycerin-based compound acts as a surfactant in the polishing composition and may help to easily remove particles and polishing pad debris remaining on the surface of the substrate to be polished. In addition, the compound may contribute to preventing the abrasive particles of the embodiment from agglomerating together to form large particles during the polishing process, thereby suppressing the generation of scratches caused by the abrasive particles on the surface to be polished.

[0046] The weight average molecular weight of the polyglycerin-based compound may be 300 g / mol to 1,200 g / mol. The weight average molecular weight may be 400 g / mol or more. The weight average molecular weight may be 500 g / mol or more. The weight average molecular weight may be 1,100 g / mol or less. The weight average molecular weight may be 1,000 g / mol or less. In such cases, it is possible to prevent foreign matter from being adsorbed on the surface of the substrate to be polished, and to effectively improve the dispersibility of the abrasive particles.

[0047] The weight average molecular weight of the polyglycerol compound can be measured by GPC (Gel Permeation Chromatography).

[0048] The polishing composition may contain 0.001% to 0.1% by weight of the polyglycerin compound. The polishing composition may contain 0.003% or more by weight of the polyglycerin compound. The polishing composition may contain 0.005% or more by weight of the polyglycerin compound. The polishing composition may contain 0.07% or less by weight of the polyglycerin compound. The polishing composition may contain 0.05% or less by weight of the polyglycerin compound. The polishing composition may contain 0.03% or less by weight of the polyglycerin compound. In such a case, organic particles remaining on the substrate surface can be easily removed. It can also be useful for reducing the number of defects occurring on the substrate surface to a certain level or less.

[0049] abrasive particles 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.

[0050] 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.

[0051] The abrasive particles may have a positive charge on the surface. 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 may be surface-modified with an aminosilane.

[0052] 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.

[0053] 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 substrate surface to be polished can be polished more smoothly and can show improved dispersibility. At the same time, the residue of the surface modifier is generated and the residue can be effectively suppressed from being adsorbed on the polished surface.

[0054] 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.

[0055] 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.

[0056] The average particle size means the average particle size of the primary particles of the abrasive particles.

[0057] In the embodiment, the content of large particles in the abrasive particles can be reduced to a certain level or less, thereby stably preventing scratches caused by the abrasive particles from occurring on the polished surface, especially on the silicon oxide film.

[0058] The LPC (Large Particle Counter) measurement of the abrasive particles is performed by applying the undiluted solution of the abrasive composition and measuring with a particle size analyzer. The measurement conditions are set as follows: Sensor Model LE400-05, Dilution Factor 1.53, Flow Pump Factor 15 ml / min, Sample Vessel 12 ml. For example, the particle size analyzer may be the Accusizer 780 model manufactured by Entegris.

[0059] The polishing composition may have a number of particles having a diameter of more than 1 μm as measured by LPC (Large particle counter) of 80 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 1 μm as measured by LPC (Large particle counter) of 70 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 1 μm as measured by LPC (Large particle counter) of 40 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 1 μm as measured by LPC (Large particle counter) of 30 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 1 μm as measured by LPC (Large particle counter) of 0.8 particles / ml or more per unit volume.

[0060] The polishing composition may have a number of particles having a diameter of more than 5 μm as measured by LPC (Large Particle Counter) of 6 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 5 μm as measured by LPC (Large Particle Counter) of 4 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 5 μm as measured by LPC (Large Particle Counter) of 2.5 particles / ml or less per unit volume. The polishing composition may have a number of particles having a diameter of more than 5 μm as measured by LPC (Large Particle Counter) of 0.4 particles / ml or more per unit volume.

[0061] The polishing composition may have a number of particles per unit volume having a diameter of more than 10 μm as measured by LPC (Large particle counter) of 2 particles / ml or less. The polishing composition may have a number of particles per unit volume having a diameter of more than 10 μm as measured by LPC (Large particle counter) of 1 particle / ml or less. The polishing composition may have a number of particles per unit volume having a diameter of more than 10 μm as measured by LPC (Large particle counter) of 0.1 particles / ml or more.

[0062] In such a case, the number of defects occurring on the polished surface can be stably reduced to a certain level or less.

[0063] In order to control the content of macroparticles in the abrasive particles within a preset range in accordance with an embodiment, the abrasive particles may be applied to the polishing composition after filtering.

[0064] The filtering of the abrasive particles may be performed through one filter. The filtering of the abrasive particles may be performed through two or more filters.

[0065] When more than one filter is applied, the filters may have different pore sizes or may have the same pore sizes.

[0066] The abrasive particles may be filtered through a primary filter. The pore size of the primary filter may be 0.05 μm to 2 μm. The pore size may be 0.08 μm or more. The pore size may be 1 μm or less. The pore size may be 0.5 μm or less. The pore size may be 0.3 μm or less.

[0067] The abrasive particles may be filtered through a primary filter and then a secondary filter. The size of the pores of the secondary filter may be 0.9 times or less than the size of the pores of the primary filter. The size of the pores of the secondary filter may be 0.8 times or less than the size of the pores of the primary filter. The size of the pores of the secondary filter may be 0.3 times or more than the size of the pores of the primary filter. The size of the pores of the secondary filter may be 0.5 times or more than the size of the pores of the primary filter.

[0068] The abrasive particles may be filtered in the order of a primary filter, a secondary filter, and a tertiary filter. The size of the pores of the tertiary filter may be 1.5 times or less than the size of the pores of the secondary filter. The size of the pores of the tertiary filter may be 1.2 times or less than the size of the pores of the secondary filter. The size of the pores of the tertiary filter may be 0.5 times or more than the size of the pores of the secondary filter. The size of the pores of the tertiary filter may be 0.8 times or more than the size of the pores of the secondary filter.

[0069] The abrasive particles may be filtered through the primary filter, the secondary filter, and the tertiary filter in this order, and then may be additionally filtered through another filter.

[0070] Exemplarily, the filter may be a filter from SAEHANGREEN or a filter from MYCROPORE CORPORATION.

[0071] When the polishing composition passes through each of the one or more filters once, the embodiment may filter the abrasive particles by circulating the polishing composition for one or more cycles. The embodiment may filter the abrasive particles by circulating the polishing composition for two or more cycles. The embodiment may filter the abrasive particles by circulating the polishing composition for 10 cycles or less. The embodiment may filter the abrasive particles by circulating the polishing composition for five cycles or less.

[0072] In this case, it is possible to stably suppress the generation of defects on the surface of the silicon oxide film due to the large particles during the polishing process.

[0073] 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 dispersing agent, a polishing rate improving agent, a polishing adjusting agent, a polishing pad protecting agent, and a preservative.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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, imidazole, and combinations thereof.

[0079] The polishing composition for semiconductor processing may further contain a dispersant.

[0080] 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.

[0081] The dispersant may include anionic small molecules, cationic polymers, organic acids, and the like.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] The polishing composition can stabilize the pH of the polishing composition by further containing a pH buffer. The pH buffer may be an acetic acid compound.

[0088] The polishing composition for semiconductor processing may include a solvent, which may be water, specifically ultrapure water.

[0089] Physical properties of the polishing composition The polishing composition for semiconductor processing may have a polishing selectivity of 1-5 for a silicon oxide film to a tungsten film.

[0090] The polishing selectivity of a silicon oxide film to a tungsten film means the ratio of the polishing rate of the polishing composition for a silicon oxide film to the polishing rate of the polishing composition for a tungsten film.

[0091] In some embodiments, the polishing selectivity can be controlled within a preset range, which can help to polish the surface of a substrate having a fine pitch tungsten pattern film more smoothly. In particular, the polishing composition having the controlled polishing selectivity can prevent the insulating film from being excessively polished when polishing the surface of a substrate having a mixture of a tungsten pattern film and an insulating film.

[0092] When measuring the polishing selectivity or polishing rate, the polishing conditions are set as follows: polishing time 60 seconds, pressure applied to wafer 1.6 psi, pressure applied to retainer ring 2.4 psi, head rotation speed 101 rpm, table rotation speed 100 rpm, and slurry supply speed 200 ml / min. The polishing pad may be HD-500C model manufactured by SK EMPULS. The polishing machine may be AP-300 model manufactured by CTS.

[0093] The polishing selectivity ratio of the polishing composition for semiconductor processing for a silicon oxide film to a tungsten film may be 1 to 5. The polishing selectivity ratio may be 1.3 or more. The polishing selectivity ratio may be 1.5 or more. The polishing selectivity ratio may be 2 or more. The polishing selectivity ratio may be 4 or less. In this case, even when polishing the surface of a substrate on which a fine tungsten pattern film is formed, it may be useful to provide a polished surface with reduced occurrence of defects.

[0094] The polishing rate of the polishing composition for semiconductor processing against a silicon oxide film may be 500 Å / min or more. The polishing rate may be 700 Å / min or more. The polishing rate may be 900 Å / min or more. The polishing rate may be 1,600 Å / min or less. The polishing rate may be 1,400 Å / min or less. The polishing rate may be 1,200 Å / min or less.

[0095] The polishing rate of the polishing composition for semiconductor processing against a tungsten film may be 120 Å / min or more. The polishing rate may be 200 Å / min or more. The polishing rate may be 300 Å / min or more. The polishing rate may be 400 Å / min or more. The polishing rate may be 500 Å / min or more. The polishing rate may be 1,000 Å / min or less.

[0096] The Ra value of the tungsten film measured after polishing with the polishing composition for semiconductor processing for 60 seconds may be 3 nm or less. The Ra value may be 2 nm or less.

[0097] In such a case, the polishing composition can provide a substrate having a smoother surface while still containing a tungsten micropattern.

[0098] The Ra value is measured in accordance with ISO 4287.

[0099] The electrical conductivity of the polishing composition for semiconductor processing may be 200 μS / cm or more. The electrical conductivity may be 250 μS / cm or more. The electrical conductivity may be 300 μS / cm or more. The electrical conductivity may be 350 μS / cm or more. The electrical conductivity may be 1,000 μS / cm or less. In this case, it may be useful for allowing the oxidation reaction of the tungsten film to proceed smoothly. And, the polishing composition may contribute to polishing the surface to be polished at an excellent polishing rate.

[0100] The pH of the polishing composition for semiconductor processing may be 1.5 to 4.5. The pH may be 2 or more. The pH may be 2.5 or more. The pH may be 4 or less. In such cases, it is useful for improving the polishing properties of the polishing composition, particularly for tungsten films, so that the degree of step generation between the tungsten film and the insulating film on the polished surface can be reduced to a certain level or less.

[0101] The pH of the polishing composition is measured with a pH meter.

[0102] The polishing composition for semiconductor processing may have a zeta potential of +5 mV to +50 mV. The zeta potential may be +10 mV or more. The zeta potential may be +40 mV or less.

[0103] The zeta potential of the abrasive particles may be +5 mV to +50 mV. The zeta potential may be +10 mV or more. The zeta potential may be +40 mV or less.

[0104] In such a case, the polishing composition can exhibit stable dispersibility and excellent polishing properties for the surface of the substrate.

[0105] The polishing composition for semiconductor processing may be a polishing composition for tungsten. The polishing composition for tungsten means a polishing composition that is used to polish not only a substrate on which only a tungsten film is formed, but also a substrate on which a tungsten film and a film of another material are mixed, that is, a substrate on which a tungsten pattern film or the like is formed.

[0106] The polishing composition for semiconductor processing may be a polishing composition for a secondary tungsten polishing process. The description of the secondary tungsten polishing process is omitted because it is the same as the above description.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] The process of polishing a substrate can optionally further include conditioning the surface of the polishing pad prior to polishing.

[0111] The polishing composition for semiconductor processing can polish a wafer in contact with the polishing pad while penetrating toward the substrate.

[0112] 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.

[0113] 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.

[0114] The description of the polishing composition for semiconductor processing is omitted since it is the same as that described above.

[0115] The method for manufacturing a substrate may further include a cleaning process for cleaning the substrate after polishing.

[0116] The cleaning process may be performed by cleaning the polished substrate with purified water and an inert gas.

[0117] 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.

[0118] Production Example: Production of Polishing Composition Example 1: 3 wt% of colloidal silica surface-modified with 38 ppm (by weight) of (3-aminopropyl)triethoxysilane as abrasive particles, 0.005 wt% of iron(III) nitrate enneahydrate as an iron ion compound, 0.012 wt% of propane diacid as an iron ion stabilizer, 0.0026 wt% of acetic acid as a pH buffer, and 0.3 wt% of hydrogen peroxide as an oxidizer were added to and mixed with ultrapure water as a solvent to prepare a polishing composition having a total weight of 100%.

[0119] The abrasive particles used were ones that had been filtered twice. Specifically, a filter with a pore size of 0.1 μm made by SAEHANGREEN was used as the first filter, a filter with a pore size of 0.07 μm made by SAEHANGREEN was used as the second filter, and a filter with a pore size of 0.07 μm made by MYCROPORE CORPORATION was used as the third filter. The polishing composition was filtered by passing it through the first filter, the second filter, and the third filter in that order. The filtering was performed twice in total to filter the abrasive particles.

[0120] Example 2: A polishing composition of 100 wt % in total was prepared under the same conditions as in Example 1, except that 0.01 wt % polyglycerin was further added as a surfactant (ultrapure water was removed by the same weight).

[0121] Example 3: A polishing composition was prepared in a total amount of 100 wt % under the same conditions as in Example 1, except that the content of the iron ion compound was 0.009 wt %.

[0122] Example 4: A polishing composition was prepared in a total amount of 100 wt % under the same conditions as in Example 1, except that the content of the iron ion compound was 0.014 wt %.

[0123] Comparative Example 1: A polishing composition of 100% by weight in total was prepared under the same conditions as in Example 1, except that the iron ion compound and the iron ion stabilizer were not used.

[0124] The content of each component in the polishing composition of each Example and Comparative Example is shown in Table 1 below, and the average diameter of the abrasive particles (diameter of primary particles), pH, zeta potential and electrical conductivity of the polishing composition of Example 1 are shown in Table 2 below.

[0125] Evaluation example: Measurement of polishing characteristics Using different polishing compositions of the Examples and Comparative Examples, a tungsten film having a thickness of 7000 Å and a silicon oxide film having a thickness of 2 μm were polished using an AP-300 polisher from CTS Co., Ltd. The tungsten film and the silicon oxide film were formed on different wafers, and the diameter of the wafers was 300 mm.

[0126] The polishing conditions were set as follows: polishing time 60 seconds, pressure applied to wafer 2.4 psi, pressure applied to retainer ring 4.1 psi, head rotation speed 101 rpm, table rotation speed 100 rpm, slurry supply speed 200 ml / min. SK Empulse's HD-500C model was used as the polishing pad.

[0127] The difference in height between the tungsten pattern film and the silicon oxide film before and after polishing was measured for the polished wafer, and the polishing rates of the tungsten film and the silicon oxide film, and the polishing selectivity of the silicon oxide film to the tungsten film were calculated from the difference.

[0128] The measured and calculated values ​​for each of the examples and comparative examples are shown in Table 3 below.

[0129] Evaluation example: Evaluation of LPC measurement and defect detection The number of particles with a diameter of more than 1 μm, the number of particles with a diameter of more than 5 μm, and the number of particles with a diameter of more than 10 μm from the polishing compositions of Examples 1 and 2 were measured using a particle size analyzer, an Accusizer 780 model from Entegris. When measuring the number of large particles, the polishing composition was put into the particle size analyzer without dilution, and the sensor model was set to LE400-05, Dilution Factor 1.53, Flow Pump Factor 15 ml / min, and Sample Vessel 12 ml.

[0130] From the measured values ​​for each example, the number of large particles per volume of the polishing composition was calculated.

[0131] Thereafter, the surface of the wafer covered with a silicon oxide film was polished with the polishing compositions of Examples 1 and 2. The polishing conditions were set as follows: polishing time 60 seconds, pressure applied to the wafer 1.6 psi, pressure applied to the retainer ring 2.4 psi, head rotation speed 101 rpm, table rotation speed 100 rpm, and slurry supply speed 200 ml / min. The polishing pad used was the HD-500C model manufactured by SK Empulse.

[0132] After the polished wafer surface was cleaned with a brush, the number of defects detected on the wafer surface was measured.

[0133] The detection of defects after polishing for each example was carried out twice.

[0134] The measured values ​​for each example are shown in Table 4 below.

[0135] Evaluation example: Evaluation of the presence or absence of tungsten protrusion The surface of a wafer having a tungsten pattern film and a silicon oxide film formed thereon was polished with the polishing composition of Example 1. The wafer had a pattern density of 50%.

[0136] The polishing conditions were set as follows: polishing time 60 seconds, pressure applied to wafer 2.4 psi, pressure applied to retainer ring 4.1 psi, head rotation speed 101 rpm, table rotation speed 100 rpm, slurry supply speed 200 ml / min. SK Empulse's HD-500C model was used as the polishing pad.

[0137] After polishing was completed, the cross section of the wafer was photographed and the difference in height between the tungsten film and the silicon oxide film before and after polishing was measured. From the difference in height, the polishing rate of the silicon oxide film, the polishing rate of the tungsten film, and the polishing selectivity of the silicon oxide film to the tungsten film were calculated.

[0138] The calculated values ​​of the polishing rate and the polishing selectivity are shown in Table 5 below.

[0139] [Table 1] Rs / i: Ratio of iron ion stabilizer content (by weight) to iron ion content (by weight)

[0140] [Table 2]

[0141] [Table 3]

[0142] [Table 4]

[0143] [Table 5]

[0144] Referring to Tables 1 and 3, it can be seen that as the content of iron ions increases, the polishing rate of the silicon oxide layer decreases and the polishing rate of the tungsten layer increases.

[0145] Referring to Table 4, it was found that Example 2 had a much smaller number of large particles and a smaller number of defects on the polished surface than Example 1. This means that the surfactant contributes to suppressing the formation of large particles in the polishing composition.

[0146] When the cross section of the wafer after polishing was observed, it was found that when the patterned wafer was polished with the polishing composition of Example 1, the step between the tungsten pattern film and the silicon oxide film was slight.

[0147] 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. comprising abrasive particles, iron ions, and an iron ion stabilizer; The iron ion stabilizer contains two or more carboxyl groups, A polishing composition for semiconductor processing, having an electrical conductivity of 200 μS / cm to 800 μS / cm.

2. 2. The polishing composition for semiconductor processing according to claim 1, wherein the iron ion stabilizer is any one selected from the group consisting of ethanedioic acid, propanedioic acid, butanedioic acid, pentanedioic acid, hexanedioic acid, heptanedioic acid, and combinations thereof.

3. 2. The polishing composition for semiconductor processing according to claim 1, wherein the ratio of the content (by weight) of the iron ion stabilizer to the content (by weight) of the iron ions is 3 to 50.

4. The iron ions were added at 1×10 －４ Weight%~5×10 －３ 2. The polishing composition for semiconductor processing according to claim 1, comprising:

5. The polishing composition for semiconductor processing according to claim 1 , further comprising a polyglycerin-based compound.

6. The polishing composition for semiconductor processing according to claim 5, wherein the weight average molecular weight of the polyglycerin-based compound is 300 g / mol to 1,200 g / mol.

7. 6. The polishing composition for semiconductor processing according to claim 5, comprising 0.001% by weight to 0.1% by weight of the polyglycerin compound.

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

9. 2. The polishing composition for semiconductor processing according to claim 1, having a pH of 1.5 to 4.

5.

10. 2. The polishing composition for semiconductor processing according to claim 1, wherein the number of particles having a diameter of more than 1 μm per unit volume as measured by a large particle counter (LPC) is 80 particles / ml or less.

11. 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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