TWI633178B - Slurry composition, rinse composition, substrate polishing method and rinsing method - Google Patents

Abstract

The invention provides a slurry composition, a cleaning composition, a substrate polishing method and a cleaning method for chemical mechanical polishing (CMP).

The slurry composition of the present invention is a slurry composition for chemical mechanical polishing, which comprises: water; polishing abrasive particles; and more than one water-soluble polymer, the water-soluble polymer comprising a polyvinyl alcohol structural unit. When a water-soluble polymer is present in the composition, its polyalkylene oxide structural unit and polyvinyl alcohol structural unit can form a main chain or a side chain of the water-soluble polymer. The slurry composition of the present invention may contain a pH-adjusting agent, and may contain a water-soluble polymer selected from a cellulose-based polymer and a polyalkylene oxide-based polymer, and may further contain a haze improving agent. 1 to 5000 ppm of water-soluble polymer may be present in the slurry composition.

Description

Slurry composition, cleaning composition, substrate polishing method, and cleaning method

The present invention relates to a semiconductor substrate polishing technology, and more specifically, to a slurry composition, a cleaning composition, a substrate polishing method, and a cleaning method for chemical mechanical polishing (CMP) and the like.

Silicon wafers, which are semiconductor substrates used in the manufacture of semiconductor substrates, are subjected to various photolithography, deposition processes, polishing processes, and the like, and are used to provide semiconductor devices. Regarding silicon wafers, since a large number of process steps for manufacturing semiconductor devices are applicable, and it is also required to improve the yield of semiconductor devices, the surface quality of the above silicon wafers is strictly required. In order to mirror polish silicon wafers to ensure surface quality, chemical mechanical polishing (CMP) technology has been applied since before.

In the CMP during polishing of silicon wafers, generally, the silicon wafer is held on a carrier for fixing the silicon wafer and the silicon wafer is clamped to a substrate containing a synthetic resin foam or flock. An aqueous composition (hereinafter referred to as a slurry composition) in which colloidal particles such as silicon dioxide, alumina, cerium oxide, and zirconia are dispersed is supplied between upper and lower pressure plates of polishing cloth such as leather-like synthetic leather. Press and rotate while polishing.

In the CMP of silicon wafers, with the increase in demand in recent years, higher performance of semiconductor devices and higher density of products, there has been a strong demand for improving productivity and surface quality. The following issues can be cited: improvement of polishing speed, Surface roughness, haze (surface haze), flat Frankness (collapse (face collapse), SFQR (Site Flatness Quality Requirements, flatness), ESFQR (Edge Site Flatness Quality Requirements, edge flatness)), reduction of scratches, etc.

Techniques for improving the surface properties of semiconductor substrates have been proposed so far. For example, Japanese Patent Application Laid-Open No. 2014-38906 (Patent Document 1) describes a polyvinyl alcohol-containing substance whose purpose is to prevent particles from adhering to a polished surface of a polishing object. As a polishing composition for a skeleton structure. Furthermore, Japanese Patent Application Laid-Open No. 11-140427 (Patent Document 2) describes a polishing liquid and a polishing method containing a chain-like hydrocarbon polymer having a carbon long chain skeleton and a hydroxyl lower alkylene group in a side chain.

Although these technologies are known, the size of the device is required to be further miniaturized as the density of semiconductor devices is required, and in order to improve the yield of integrated circuit products, it is required to further improve the surface state of the semiconductor substrate.

[Prior technical literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2014-38906

[Patent Document 2] Japanese Patent Laid-Open No. 11-140427

The present invention has been made in view of the above-mentioned problems, and an object thereof is to provide a slurry composition, a cleaning composition, a substrate polishing method, and a cleaning method capable of improving the surface state of a semiconductor substrate.

According to the present invention, a slurry composition for chemical mechanical polishing is provided, which contains: water; polishing abrasive particles; and One or more water-soluble polymers including a polyvinyl alcohol structural unit.

In the present invention, the water-soluble polymer may be one or more kinds of water-soluble polymers each including a polyalkylene oxide structural unit or a polyvinyl alcohol structural unit. When there is one kind of the water-soluble polymer in the slurry composition, the polyalkylene oxide structural unit and the polyvinyl alcohol structural unit of the water-soluble polymer may form a main chain or a side chain of the water-soluble polymer. . The present invention preferably further comprises a pH adjuster. The present invention may contain a water-soluble polymer selected from a cellulose-based polymer and a polyalkylene oxide-based polymer. In the present invention, a haze improving agent may be contained. In the present invention, the water-soluble polymer preferably contains 1 to 5000 ppm.

Furthermore, according to the second configuration of the present invention, there is provided a cleaning composition for polishing a substrate, comprising: water; and one or more water-soluble polymers, the water-soluble polymer including a polyvinyl alcohol structural unit.

In the present invention, the water-soluble polymer may be one or more kinds of water-soluble polymers each including a polyalkylene oxide structural unit or a polyvinyl alcohol structural unit. Further, when there is one kind of the water-soluble polymer in the slurry composition, the polyalkylene oxide structural unit and the polyvinyl alcohol structural unit of the water-soluble polymer may form a main chain of the water-soluble polymer or Side chain. The present invention may contain a water-soluble polymer selected from a cellulose-based polymer and a polyalkylene oxide-based polymer. In the present invention, a haze improving agent may be further contained. The water-soluble polymer may contain 1 to 5000 ppm.

Furthermore, in the third configuration of the present invention, a substrate polishing method is provided, which includes the steps of attaching the above-mentioned slurry composition to a polishing substrate; and polishing the polishing substrate with the above-mentioned slurry composition on a polishing pad. step.

In addition, according to a fourth configuration of the present invention, there is provided a method for cleaning a polished substrate, comprising the step of cleaning the polished substrate using the cleaning composition described above.

According to the present invention, it is possible to provide a micro unevenness that can improve the reference LPD (Least Perceptible Chromaticity Difference), haze, Haze Scratch, and Haze Line, in other words, Nano-scale polishing defect slurry composition, cleaning composition, substrate polishing method and cleaning method.

Hereinafter, the present invention will be described using embodiments, but the present invention is not limited to the following embodiments. In addition, in this embodiment, the nano-scale polishing defect is referred to as the following nano-scratch. The slurry composition or cleaning composition of the present invention contains one or more kinds of water-soluble polymers each including a polyalkylene oxide structural unit or a polyvinyl alcohol structural unit. Regarding the water-soluble polymer of this embodiment, in the first aspect, two different water-soluble polymers of polyoxyalkylene oxide and polyvinyl alcohol can be formed in each composition. In the second aspect of the present invention, the water-soluble polymer of this embodiment may also exist in each composition as a graft polymer in which a polyalkylene oxide structural unit or a polyvinyl alcohol structural unit constitutes a main chain or a side chain. in. In the case where the polyvinyl alcohol structural unit is present in the main chain or the side chain, a part of the hydroxyl group may be substituted with a fluorenyloxy group. As the fluorenyloxy group, a fluorenyloxy group having 2 or more carbon atoms can be preferably used, and a (CH ₃ COO—) group is particularly preferred.

The polyoxyalkylene oxide in the polyalkylene oxide structural unit may be a polyethylene oxide, a polypropylene oxide, or a poly (ethylene oxide-propylene oxide) copolymer, and the copolymer may be a random copolymer. It can also be a block copolymer. The repeating chain length of the polyalkylene oxide and alkylene oxide is 1 to 1,000, more preferably 2 to 300, and even more preferably 3 to 200.

The water-soluble polymer in this embodiment constitutes polyalkylene oxide, polyvinyl alcohol, etc. In the case of an independent water-soluble polymer, its presence is preferably 5:95 to 40:60 in terms of mole%. In terms of improving the polishing defect of nanometers, it can be set to 10:90 to 30:70. range. Moreover, the molecular weight of polyalkylene oxide and polyvinyl alcohol can be made into the range of 1000-10000000.

In the case where the polyalkylene oxide and polyvinyl alcohol form a graft polymer in this embodiment, the molecular weight of the graft polymer can be set to 5000 to 500,000 based on the weight average molecular weight. If a solution such as a slurry solution is considered The rheological properties can be set in the range of 10,000 to 300,000, more preferably in the range of 10,000 to 200,000.

The presence of the polyalkylene oxide skeleton and the polyvinyl alcohol skeleton in the graft polymer of this embodiment is preferably 5:95 to 40:60 in terms of mole%. In terms of improving the nano-polished defects, It is preferable to set the range from 10:90 to 30:70.

The alkylene oxide skeleton of this embodiment may be ethylene oxide, propylene oxide, or these may be randomized or blocked to form a chain. The best alkylene oxide is ethylene oxide.

When adding the said water-soluble polymer as a graft polymer, specifically, as this water-soluble polymer, the water-soluble polymer which has a following general formula (1) is mentioned.

In the general formulae (1) and (1 ′), R is a hydroxyl group or a fluorenyl group having a carbon number of 2 or more, a is an integer of 1 to 10,000, and M1, M2, N1, and N2 are real numbers of 0 or more (grafting) rate). In the general formula (1), R1 is a hydrogen atom or a fluorenyl group. In addition, R ₂ and R ₃ are linear or branched alkyl groups having 2 or more carbon atoms which may be the same or different, and b is an integer of 2 to 10,000. In addition, R in the general formulae (1) and (1 ′) may be a structure in which a hydroxyl group and a fluorenyl group are mixed, that is, a structure in which the fluorenyl group is saponified to a hydroxy group.

In this embodiment, as a preferable water-soluble polymer, specifically, the water-soluble polymer which has the following structural formula (2) and (3) is mentioned, for example. In addition, a part or a terminal hydroxyl group of the hydroxyl groups of the following structural formulae (2) and (3) may be substituted with a fluorenyloxy group.

In this embodiment, the water-soluble polymer may exist in the slurry composition in a range of 1 ppm (0.001 mass%) to 5000 ppm (0.5 mass%). In addition, from the viewpoint of maintaining the polishing rate at a throughput that can be actually produced, the addition is preferably performed in a range of 10 ppm to 1000 ppm.

The slurry composition of this embodiment may contain a polymer having a tertiary amine structure in the main chain structure as a haze improving agent for improving the LPD and haze of the surface of a semiconductor substrate.

The above-mentioned polymer used in the present invention can be obtained by using an alkylene oxide containing at least ethylene oxide and a molecule having 2 or more primary amine groups and / or secondary amine groups in the molecule and containing 4 to 100 N atoms. An active hydrogen of a polyamine compound is produced by addition polymerization. The weight average molecular weight of the polymer can be set in the range of 5000 to 100,000. In addition, in terms of providing water solubility for use in the CMP process, it is preferable to set the number of N atoms contained in the polymer of this embodiment to 2 to 10,000 or less, to improve haze and provide In terms of sufficient CMP process suitability, the number of N atoms is preferably in the range of 2 to 1,000. Hereinafter, in this embodiment, this polymer is referred to as an alkylene polyalkylene oxide amine polymer (hereinafter abbreviated as APOA).

In this embodiment, examples of the polyamine compound that provides a main chain structure include poly (ethylene) amines such as triethylene tetramine, tetra ethylene pentamine, penta ethyl hexaamine, and hexa ethyl heptaamine. Polyamines; and polyalkylenes such as polyethyleneimine obtained by polymerization of ethyleneimine Imine and so on. These compounds may be used alone, or two or more of them may be used in combination to form the polyamine backbone structure of this embodiment.

Examples of the alkylene oxide added to the main chain skeleton include ethylene oxide, propylene oxide, and butylene oxide. These alkylene oxides may be used alone or in combination of a plurality of types.

The alkylene oxide skeleton that can be used in this embodiment is preferably selected from an ethylene oxide skeleton and / or a polypropylene skeleton. The ratio of ethylene oxide in the alkylene oxide added to the polymer of this embodiment is 5% or more, preferably 10% or more. By setting 50% to 90%, a better CMP process can be provided. Sex. In the case where a propylene oxide skeleton is contained in the present embodiment, a range of 10% to 20% is similarly preferable in terms of expanding the process range.

The polymer of this embodiment can be easily produced by a usual method. For example, the polymer of this embodiment can be subjected to addition polymerization (graft polymerization) of an alkylene oxide with the above-mentioned polyamine compound of a starting material at a temperature of 100 to 180 ° C. and a pressure of 1 to 10 under an alkaline catalyst. While manufacturing.

The addition state of the alkylene oxide to the polyamine compound which is the main chain skeleton is not particularly limited. When two or more types of alkylene oxide are added, the form may be block or random. shape. The weight average molecular weight of the polymer in this embodiment can be set to 5,000 or more, preferably 10,000 or more, and can be set to a range of 100,000 or less, and further 80,000 or less. In the case where the weight average molecular weight is too small, the haze cannot be sufficiently improved. In the case where the weight average molecular weight is too large, the dependence of the addition amount of each characteristic increases and the process range is reduced, which is not good.

In the present specification, the main chain structure means a structure containing two or more repeating structural units including a tertiary amine graft-polymerized with a polyalkylene oxide. Furthermore, the tertiary amine constituting the main chain structure of this embodiment preferably contains N-alkylene. The number of C atoms constituting the N-alkylene group is not particularly limited, and can be selected from linear or branched alkylene groups having a C atom number in the range of 2 to 10.

As a polymer of this embodiment, specifically, the addition and polymerization of an alkylene oxide and a polyethylen polyamine are exemplified, and it is formed under a main chain structure containing at least a tertiary amine structure. The polymer represented by the general formula (1).

In the general formula (1), x and y are positive integers, and R ₄ represents an alkylene group. R ₃ and R ₄ represent a linear or branched alkylene group having a carbon number of 2 or more. In terms of productivity, cost, and haze improvement properties, the most preferred R ₃ is ethylene group. In this embodiment, x is 2 to 1000, preferably 2 to 20, and y can be set to a range of 2 to 10,000, preferably 2 to 500. If the chain length of the R ₄ O chain becomes too long, the effect of improving the surface characteristics is reduced. The reason is that if y is 10,000 or more, the dependency of the addition amount of each characteristic will increase, which will adversely affect the process range. R ₄ O can be formed using two or more kinds of alkylene oxides. In the case of this embodiment, different alkylene oxides may be block-shaped or random.

Regarding the compounds provided by the above formulae (1) to (4) in the present invention, it is preferable to set the solubility parameter in the range of 9 to 16. In addition, in this specification, the so-called solubility parameter (SP) refers to a method using the Fedors described in Ueda et al., Coatings Research, No. 152, Oct. 2010, pages 41 to 46, based on SP value of the water-soluble polymer obtained from the SP value of the monomer.

Furthermore, in the present invention, other water-soluble polymers may be used in combination. Examples of such a water-soluble polymer include a homopolymer or a copolymer produced by polymerizing an ethylene-based monomer. Examples of such vinyl-based monomers include styrene, chlorostyrene, α-methylstyrene, and divinylbenzene; vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caprylate, and capric acid Vinyl ester, vinyl laurate, vinyl myristate, vinyl stearate, Vinyl adipate, vinyl (meth) acrylate, vinyl methacrylate, vinyl sorbate, vinyl benzoate, vinyl cinnamate and other carboxylic acid vinyl esters; acrylonitrile, limonene, cyclohexene; 2-vinylpyridine, 3-vinylpyridine, 4-vinylpyridine, N-vinylpyrrolidone; N-vinylacetamide, N-vinylmethylacetamide and other N-vinyl compounds; Vinyl furan, 2-vinyloxytetrapyran and other cyclic ether vinyl compounds; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, pentyl vinyl ether , 2-ethylhexyl vinyl ether, octyl vinyl ether, nonyl vinyl ether, dodecyl vinyl ether, cetyl vinyl ether, octadecyl vinyl ether, butoxyethyl Vinyl ether, cetyl vinyl ether, phenoxyethyl vinyl ether, allyl vinyl ether, methallyl vinyl ether, glycidyl vinyl ether, 2-chloroethyl vinyl Monovinyl ethers such as methyl ether, cyclohexyl vinyl ether; and ethylene glycol monovinyl ether, polyethylene glycol monovinyl ether, propylene glycol monoethylene Ether, polypropylene glycol monovinyl ether, 1,3-butanediol monovinyl ether, 1,4-butanediol monovinyl ether, hexanediol monovinyl ether, neopentyl glycol monovinyl ether , Homopolymer such as trimethylolpropane monovinyl ether, glycerol monovinyl ether, pentaerythritol monovinyl ether, 1,4-cyclohexanedimethanol monovinyl ether, etc. Polymer or copolymer; for these, in order to appropriately increase the water solubility, the degree of saponification can also be adjusted.

In addition to the acrylic resin, cellulose derivatives such as methyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, and hydroxypropyl methyl cellulose may be used in the present invention. As the cellulose derivative, an average molecular weight of 50,000 to 2,000,000 can be used.

Specific examples of the water-soluble polymer that can be used in combination include poly-N-vinylpyrrolidone, poly-N-vinylacetamide, polyglycerin, and PEG (Polyethylene) having a molecular weight of 1,000 to 1,000,000. glycol (polyethylene glycol) / PEO (Polyethylene oxide, polyethylene oxide), PEG-PPG (Polypropylene glycol, polypropylene glycol) block copolymer, alkylene oxide ethylene diamine adduct (EO mass ratio 35%, PPG molecular weight 4400, reverse type), poly-2-ethyl Oxazoline (Poly (2-ethyl-2-oxazoline, average molecular weight 500,000), polyvinyl alcohol (average molecular weight 200000), polyacrylic acid (average molecular weight 25000), polyacrylate (average molecular weight 5000)).

In the case where the alkylene oxide polyalkylene oxide polymer is present in the slurry composition of the present invention, the amount of addition may be in the range of 1 ppm (0.001% by mass) to 5000ppm (0.5% by mass). From the viewpoint of maintaining the polishing speed of the silicon wafer to a practically processable amount, it is preferable to add it in a range of 5 ppm to 1000 ppm, and it is more preferable to adjust the composition of other slurries. It is added in the range of more preferably 5 ppm to 500 ppm.

The slurry composition of the present invention may contain polishing ingredients such as polishing abrasive grains, acids or bases, buffers, catalysts, various salts, etc., in addition to the water-soluble polymer described above. As the polishing abrasive used in the present invention, a polishing abrasive generally used for polishing can be used. Examples of the polishing abrasive particles include carbides, nitrides, oxides, borides, and diamonds of metals, metals, or semimetals.

As the polishing abrasive particles that can be used in the present invention, metal oxides that can polish the substrate surface without causing harmful scratches (scratches) or other defects on the substrate surface are preferred. Preferred polishing abrasives for metal oxides include, for example, alumina, silica, titania, cerium oxide, zirconia, and magnesia, and co-formed products thereof, mixtures thereof, and the like, and And other chemical mixtures. Typically, the polishing abrasive particles are selected from the group consisting of alumina, cerium oxide, silicon dioxide, zirconia, and combinations thereof. Silicon dioxide, especially colloidal silicon dioxide and cerium oxide, are preferred polishing abrasive particles, and more preferably colloidal silicon dioxide.

The polishing abrasive particles of the slurry composition of the present invention can disperse the polishing abrasive particles in a preferred liquid carrier, and add various additives such as water-soluble polymers to form the dispersion or suspension. In most cases, in order to reduce transportation costs, the slurry composition is manufactured in a state where the concentration is further concentrated than at the time of polishing. In the following, with regard to the slurry composition, where the concentration is concerned, it means the form of a polishing liquid for polishing. The concentration after dilution. Examples of a preferable liquid carrier include a polar solvent, preferably water or an aqueous solvent. When polishing slurry is contained in the slurry, it is more preferable to have a concentration of 0.1% by mass or more, more preferably 0.1 in terms of the concentration at the time of polishing. ~ 50% by mass of polishing abrasive particles. In a better slurry composition, regarding the polishing abrasive particles, colloidal silica can be added in an amount of 0.1 ~ 10% by mass.

The slurry composition of the present invention can appropriately adjust the pH value in consideration of the polishing speed. In the present invention, the pH value of the slurry composition is preferably 5-12, more preferably in the polishing process of silicon wafers, and the pH value is in the range of 7-12.

From the viewpoint of improving the polishing speed, the average particle diameter of the primary particles of the polishing abrasive particles is preferably 0.01 to 3 μm, more preferably 0.01 to 0.8 μm, and even more preferably 0.02 to 0.5 μm. Furthermore, when the primary particles are aggregated to form secondary particles, the average particle diameter of the secondary particles can be set to be smaller than the viewpoint of increasing the polishing speed and reducing the surface roughness of the object to be polished. It is preferably 0.02 to 3 μm, more preferably 0.05 to 1 μm, and even more preferably 0.03 to 0.15 μm. The average particle diameter of the primary particles of the polished abrasive particles can be determined by observation with a scanning electron microscope or observation with a transmission electron microscope, image analysis, and measurement of the particle diameter. The average particle diameter of the secondary particles can be measured as a volume average particle diameter using a laser light scattering method.

In the present invention, various other additives may be used depending on polishing the substrate. As preferred additives, for example, amines, ammonium salts, alkali metal ions, film-forming agents, complexing agents, surfactants, rheology control agents, polymer stabilizers or dispersants, and / or halide ions can be present in the polishing System. The additives may be present in the polishing system in any preferred concentration.

Further, an amine compound may be added to the slurry composition, and the amine compound may be selected from a combination of aliphatic amines, cyclic amines, heterocyclic amines, aromatic amines, polyamines, and the like. In a preferred embodiment, the amine compound may include an amino acid or an amino alcohol, and may include at least one oxygen atom and at least one polar moiety. Specifically, dimethylpropanolamine (also known as (Known as 2-dimethylamino-2-methyl-1-propanol or DMAMP), 2-amino-2-methyl-1-propanol (AMP), 2- (2- Aminoethylamino) ethanol, 2- (isopropylamino) ethanol, 2- (methylamino) ethanol, 2- (diethylamino) ethanol, 2- (2- (dimethyl) Amine) ethoxy) ethanol, 1,1 '-[[3- (dimethylamino) propyl] imine] -bis-2-propanol, 2- (butylamino) ethanol, 2- (Third-butylamino) ethanol, 2- (diisopropylamino) ethanol, N- (3-aminopropyl) morpholine, and mixtures thereof.

In the present invention, in addition to an amine compound, an ammonium salt may be added. For example, an amine (for example, tetramethylammonium hydroxide (TMAH)) and a quaternary ammonium compound may be used.

Alkali metal ions can also be present in the slurry composition as the opposite ions of various salts. Preferred alkali metal ions include monovalent base metal ions of Group I of the periodic table. Specific examples of the alkali metal ion include sodium ion, potassium ion, rubidium ion, and cesium ion. Potassium ion and cesium ion are preferable, and potassium ion is more preferable.

Furthermore, in the present invention, an anticorrosive agent may be used together with the polishing system. Examples of the anticorrosive agent include alkylamines, alkanolamines, hydroxylamines, phosphates, sodium lauryl sulfate, fatty acids, polyacrylates, Polymethacrylate, polyvinylphosphonate, polymalate, polystyrenesulfonate, polyvinylsulfonate, benzotriazole, triazole, benzimidazole, and mixtures thereof.

Furthermore, in the present invention, a chelating agent or the like may be optionally added to the slurry composition. Examples of the chelating agent include carbonyl compounds such as acetam pyruvate; carboxylates such as acetate and aryl carboxylates; carboxylates containing at least one hydroxyl group; for example, glycolate, lactate, and glucose Acid salts, gallic acid, and the like; dicarboxylic acid salts, tricarboxylic acid salts, and polycarboxylic acid salts (e.g., oxalate, phthalate, citrate, succinate, tartaric acid) Salt, malate, disodium EDTA and other ethylenediaminetetraacetates); and mixtures thereof. Preferred chelating agents include, for example, glycols such as ethylene glycol, catechol, catechol, and tannic acid, triols or polyhydric alcohols, and phosphate-containing compounds.

In the present invention, a surfactant, a viscosity modifier, and a coagulant can be optionally used together with the polishing system. Examples of preferred viscosity modifiers include urethane polymers and acrylates containing at least one acryl fluorenyl unit. Specifically, as the viscosity modifier, a low-molecular-weight carboxylate and a high-molecular-weight polyacrylamide compound can be cited. As preferred surfactants, for example, cationic surfactants, anionic surfactants, Anionic polymer electrolytes, non-ionic surfactants, amphoteric surfactants, fluorinated surfactants, mixtures thereof, and the like.

The substrate can be polished using a polishing system equipped with a suitable polishing pad. As the polishing pad, for example, woven and non-woven polishing pads can be preferably used. Specifically, as the preferred polishing pad, a synthetic resin polishing pad can be used. Examples of the preferred polymer include polyvinyl chloride, polyvinyl fluoride, nylon, fluorocarbon, polycarbonate, polyester, and polyacrylate. , Polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, and the like to form articles and mixtures thereof.

In addition, the slurry composition and substrate polishing method of the present invention can be applied not only to a silicon substrate, but also to a silicon substrate, a sapphire substrate, a SiC substrate, a GaAs substrate, and a GaN substrate formed with a polycrystalline silicon film, a SiO ₂ film, and a metal wiring film. 2. Polishing treatment can be applied to substrates such as TSV (Through Silicon Via) formation substrates. In addition, the present invention can be applied to a method of adjusting a slurry composition in advance and polishing the polishing composition on a polishing pad while supplying the adjusted slurry composition to a polishing substrate, and can also be applied to a so-called on-platen The polishing method of adjustment and adjustment, the so-called adjustment and adjustment on the platen, is to supply the dilution liquid and the slurry stock solution to the polishing pad and adjust the slurry composition for polishing the substrate near the polishing pad.

Furthermore, in the present invention, an aqueous solution containing water and a water-soluble polymer represented by the general formula (1) may be used as a cleaning solution for washing the polished substrate after the polishing treatment. Regarding the cleaning composition of this embodiment, in addition to water and the water-soluble polymer represented by the general formula (1), a cellulose-based polymer, a polyalkylene oxide-based polymer, and others may be added. Water-soluble polymers, pH adjusters such as acids and alkalis, etc. are used without removing various additives for polishing abrasive particles.

So far, the present invention has been described in detail using the embodiments. Hereinafter, the present invention will be described using more specific examples. In addition, the following embodiments are used to understand the inventors, and are not intended to limit the inventors in any sense.

[Example]

An additive having the following structural formula is added to a slurry solution to prepare a slurry composition of the present invention, and its LPD and surface haze (DWO Haze) are measured. The adjustment of the slurry composition and the polishing conditions of the silicon wafer are as follows.

1. Adjustment of slurry composition (concentrate of polishing liquid)

Polyvinyl alcohol-polyethylene oxide graft copolymer (80: 20 mol%, Mw = 93600, saponification degree 98.5%, trunk: polyvinyl alcohol, added as an exemplary compound of the water-soluble polymer of structural formula (2) Side chain: polyethylene oxide), polyethylene oxide-polyvinyl alcohol graft copolymer (25: 75 mol%, Mw = 45000, saponification degree) as an exemplary compound of the water-soluble polymer of structural formula (3) 92 ~ 99%, backbone: polyethylene oxide, side chain: polyvinyl alcohol), an alkylene oxide polyamine polymer (EO: PO = 8: 2, average nitrogen number 5, Mw = 46000), and each of the slurry compositions having the composition shown in Table 1 below was adjusted. In addition, Examples 1 to 3 are Examples, and Example 4 is a Comparative Example.

2. Polishing conditions

Using the slurry composition prepared in 1, the 12-inch p-type silicon wafer (resistivity (0.1 ~ 100Ω‧cm), crystal orientation <100>) was washed with hydrofluoric acid (0.5%) at 23 ° C. The natural oxide film was removed in 2 minutes, and then the slurry composition concentrate was diluted 20 times with water to make a polishing liquid, and a polishing treatment was applied under the following conditions.

(1) Polishing device: 12-inch single-sided polisher, SPP800S manufactured by Okamoto Machinery Works

(2) Wafer head: template method

(3) Polishing pad: SPM3100 manufactured by DOW Company

(4) Platen rotation speed: 31rpm

(5) Turning speed of polishing head: 33rpm

(6) Polishing pressure: 3psi = 210g / cm ² = 20.7kPa

(7) Supply of slurry: 500mL / min (continuous)

After polishing, silicon wafers were subjected to SC-1 (ammonia (29% by mass aqueous solution): hydrogen peroxide (31% by mass aqueous solution): pure water = 1: 1: 4 (volume ratio) solution) at 23 ° C for 20 minutes. Wash in batches of minutes, and then use SC-200S, SC-1 (ammonia (29% by mass aqueous solution): hydrogen peroxide (31% by mass aqueous solution): pure water = 1: 4: 20 ( The volume ratio) solution) was washed with a PVA brush scrub at 23 ° C, and then washed with pure water.

3. Determination method

The surface roughness (haze) of the cleaned silicon wafer surface is the value of the DWO haze measured in a dark-field wide-angle oblique incidence channel (DWO) using Surfscan SP2 manufactured by KLA Tencor. As for the LPD, the same Surfscan SP2 manufactured by KLA Tencor was used, and the value of the LPD in the oblique incidence channel (DCO) was mixed using a dark field. Nano-polished defects are defined by the amount of signals whose intensity is lower than the LPD signal and the scattering intensity from the surface is locally stronger than the baseline intensity. Specifically, in this embodiment, the corresponding signals observed in the set area are counted and judged. For each measurement value, the same additive is measured at least twice under the same conditions, and the average value is used for measurement. ：: Excellent, ○: Good, △: Fair, ×: Relative evaluation of bad.

4. Results

The evaluation results are shown in Table 2 below.

Further, after the above polishing, a cleaning composition containing no polishing abrasive particles was manufactured, and the polishing substrates of Examples 1 and 2 were cleaned by brush cleaning and washed with pure water. Similarly, the LPD, haze (DWO), Nano polishing defects were evaluated and good results were obtained.

As described above, according to the present invention, it is possible to provide a slurry composition and a substrate polishing method capable of simultaneously improving polishing defects in haze, LPD, and nanometer scale.

So far, the present invention has been described using the embodiments, but the present invention is not limited to the embodiments, and can be changed within the scope conceivable by the industry, that is, other embodiments, additions, changes, and deletions, etc. As long as the functions and effects of the present invention are exerted, they are all included in the scope of the present invention.

Claims (13)

A slurry composition for chemical mechanical polishing, comprising: water; polishing abrasive particles; and more than one water-soluble polymer, the water-soluble polymer includes a polyvinyl alcohol structural unit on a main chain or a side chain, and a hydroxyl group thereof One part may be substituted with fluorenyloxy; wherein the composition has a pH value of 7 to 12. For example, in the slurry composition of claim 1, when one of the above water-soluble polymers is present in the above-mentioned slurry composition, the polyvinyl alcohol structural unit of the water-soluble polymer forms the main chain of the water-soluble polymer or Side chain. The slurry composition as claimed in claim 1 or 2, further comprising a pH adjuster. The slurry composition according to claim 1 or 2, further comprising a water-soluble polymer selected from a cellulose-based polymer and a polyalkylene oxide-based polymer. The slurry composition according to claim 1 or 2, further comprising a haze improver. The slurry composition according to claim 1 or 2, which contains 1 to 5000 ppm of the above water-soluble polymer. A cleaning composition for polishing a substrate, comprising: water; and at least one water-soluble polymer, the water-soluble polymer comprising a polyvinyl alcohol structural unit on a main chain or a side chain, and a part of hydroxyl groups thereof may be processed through Oxygen-substituted; wherein the composition has a pH of 7 to 12. The cleaning composition according to claim 7, wherein when one kind of the water-soluble polymer is present in the slurry composition, the polyvinyl alcohol structural unit of the water-soluble polymer forms the main chain or side of the water-soluble polymer. chain. The cleaning composition according to claim 78, further comprising a water-soluble polymer selected from a cellulose-based polymer and a polyalkylene oxide-based polymer. The cleaning composition of claim 78, which further contains a haze improver. The cleaning composition according to claim 78, which contains 1 to 5000 ppm of the above water-soluble polymer. A substrate polishing method, comprising: a step of attaching the slurry composition according to any one of claims 1 to 6 to a polishing substrate; and a step of polishing the polishing substrate on a polishing pad by using the slurry composition. A method for cleaning a polished substrate, comprising the step of cleaning the polished substrate using a cleaning composition according to any one of claims 7 to 11.