TWI553049B - Polishing composition, polishing composition for silicon wafer, and method for producing silicon wafer product - Google Patents

Description

Abrasive composition, abrasive composition for tantalum wafer, and method for manufacturing tantalum wafer product

The present invention relates to a grinding agent composition, an abrasive composition for a tantalum wafer, and a method of manufacturing a tantalum wafer product.

For the polishing composition used for the polishing of the wafer or the like, a slurry containing cerium oxide particles, a basic substance, a water-soluble polymer, water, and an additive as needed may be used.

The water-soluble polymer used as a grinding aid in the above abrasive composition is reported to have a substance which can dissolve cellulose, for example, hydroxyethyl cellulose (HEC), carboxymethyl cellulose (CMC), hydroxypropyl Cellulose (HPC) or the like (Patent Document 1 and Patent Document 2).

Examples of the water-soluble polymer other than the above materials include, for example, a water-soluble synthetic polymer. Water-soluble synthetic polymers are reported to have polyethylene oxide, polypropylene decylamine, polyacrylic acid (Patent Document 2); polyvinylpyrrolidone, poly N-vinylformamide (Patent Document 3); epoxy Block copolymer of ethane and propylene oxide (Patent Documents 4, 5); poly(N-fluorenylalkylene) Imine) (Patent Document 6); or a polyvinyl alcohol and a modified product thereof (Patent Document 7) may be used alone or in combination with other materials to be used as a grinding aid.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] US Patent No. 3,758,842

[Patent Document 2] Japanese Patent Laid-Open No. 02-158684

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2008-53415

[Patent Document 4] Japanese Patent Laid-Open No. Hei 10-245545

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2005-85858

[Patent Document 6] Japanese Patent Laid-Open Publication No. 2010-099757

[Patent Document 7] Japanese Patent Laid-Open Publication No. 2012-015462

However, the water-soluble polymer which can melt the cellulose will inevitably remain in the partially unreacted free fiber during the soluble treatment. If the remaining insoluble components are mixed in the abrasive composition, there is a problem that surface defects are likely to occur on the surface of the wafer after polishing. The water-soluble polymer which can dissolve cellulose is produced by using natural pulp as a raw material, but the performance (solubility, etc.) varies greatly depending on the batch of raw materials, and there are enamel wafer products after grinding. The problem of surface quality (surface defects) is not stable.

In addition, the water-soluble synthetic polymer used in the past is highly pure and is less likely to cause problems due to insoluble components, but it can be compared with The water-soluble polymer in which the cellulose is melted has a low hydrophilicity, and the polishing liquid is kept on the surface of the polishing target such as a ruthenium wafer, and the deposit is likely to remain in the polished surface of the wafer after polishing. . Therefore, in order to produce a high-quality polished product (a wafer product, etc.) more stably, it is desired to develop a water-soluble synthetic polymer having properties equivalent to or higher than that of a water-soluble polymer capable of melting cellulose. .

An object of the present invention is to provide a water-soluble synthetic polymer for improving the surface quality of a polishing target such as a polished wafer after polishing, and to improve the wettability of the surface of the object to be polished, thereby reducing the residual property. The number of particles of the polished surface after polishing and the abrasive composition of LPD (LigHt Point Defect), and the composition of the abrasive for the ruthenium wafer, and the use of the crystallization of the abrasive composition further Manufacturing method of round products. The LPD is a person who observes a bad spot when scanning the surface of a wafer by laser irradiation by a light scattering particle counter.

That is, the abrasive composition of the present invention (the aspect 1) contains cerium oxide particles, a basic substance, a water-soluble synthetic polymer, and a polishing composition for water, and is characterized in that the water-soluble synthetic composition is high. The molecule has a structural unit (1), the structural unit (1) has an oxygen-containing group and a carbonyl group, and the oxygen-containing group is an alcoholic hydroxyl group or a substituted or unsubstituted alkoxy group, and the carbonyl group is a keto group. Any one of a carbonyl group constituting a part of an ester bond or a carbonyl group constituting a part of a guanamine bond.

Further, the abrasive composition of the present invention (Section 2) contains cerium oxide particles, a basic substance, a water-soluble synthetic polymer, and water. The abrasive composition, and the water-soluble synthetic polymer is a reaction product obtained by reacting the water-soluble synthetic polymer of the above aspect 1 with an epoxy compound.

The present invention relates to an abrasive composition for a wafer comprising the abrasive composition of the above aspect 1 or aspect 2 (Section 3).

The method for producing a ruthenium wafer product according to the present invention includes the step of polishing the ruthenium wafer using the abrasive composition of any of the above aspects 1 to 3 (Section 4).

By using the water-soluble synthetic polymer of the present invention as a polishing aid, it is possible to constitute an abrasive composition having hydrophilicity equivalent to that of a conventional water-soluble polymer capable of melting cellulose. Such a water-soluble synthetic polymer is less likely to cause a change in quality than a water-soluble polymer which can dissolve cellulose. Therefore, by using the water-soluble synthetic polymer of the present invention as a grinding aid, it is possible to provide wettability to the surface of the object to be polished, and to stably provide high-quality surface characteristics (low residual particles/low LPD) An abrasive composition for a tantalum wafer of a wafer, and a method for producing a wafer product using the abrasive composition.

1‧‧‧ polishing liquid supply nozzle

2‧‧‧grinding base plate

3‧‧‧ polishing cloth

4‧‧‧ polishing head

5‧‧‧Sample Wafer

Figure 1 is a schematic view showing a one-side grinding apparatus.

An abrasive composition according to an embodiment of the present invention will be described.

The abrasive composition of the embodiment of the present invention contains cerium oxide Particle (i), basic substance (ii), water-soluble synthetic polymer (iii), and water (iv). The abrasive composition of the present embodiment may further contain an additive (v).

In the present specification, the "cerium oxide particles (i)" are a general term for particles represented by the composition formula SiO ₂ and particles obtained by surface-treating the particles. Examples of the cerium oxide particles (i) include colloidal cerium oxide, fumed silica, and precipitated cerium oxide, and modification of the surface by boric acid treatment or aluminate treatment. The surface is modified with cerium oxide. Among these, from the viewpoint of improving the surface characteristics of the tantalum wafer, colloidal cerium oxide and its surface-modified cerium oxide are more preferable. The average particle diameter of the cerium oxide particles (i) is measured by a BET method, a dynamic light scattering method, or the like.

The particle size of the cerium oxide particles (i) is not limited. The particle size of the cerium oxide particles (i) can be selected depending on the properties of the product after grinding. For example, when seeking to improve the surface characteristics after polishing, the primary particle diameter (which can be measured by the BET method) can be set to 10 to 40 nm or 10 to 20 nm, and the secondary particle diameter (which can be measured by dynamic light scattering) can be set to 20 to 80 nm or 20 to 40 nm.

The method for producing the cerium oxide particles (i) is not limited. A method for synthesizing cerium oxide particles (i) is known from a hydrothermal synthesis method of Liquid Glass, a sol-gel method from alkoxysilane or a condensate thereof, a gas phase synthesis method from ruthenium chloride, and the like. . When the object to be polished is a germanium wafer, the cerium oxide particles produced by the sol-gel method from alkoxysilane or a condensate thereof are prevented from contaminating the germanium wafer with an impurity such as an alkali metal or an alkaline earth metal ( i) is preferred.

The shape of the cerium oxide particles (i) is not particularly limited. Dioxane Specific examples of the shape of the cerium oxide particle (i) include a spherical type, a 茧 type/new type, or a type with fine protrusions. The cerium type/new cerium type cerium oxide particles are characterized by cerium oxide particles having a secondary particle diameter/primary particle diameter ratio of 1.5 or more and 2.5 or less. Among the cerium-type cerium oxide particles, cerium oxide particles prepared by a method including a step of hydrolyzing a condensed body of alkoxy decane are sometimes referred to as neodymium-type cerium oxide particles (patent No. 4712556). . In this manual, if there is no special statement of "茧 type (excluding new type)", the so-called type also includes new type. From the viewpoint of improving both the polishing speed and the surface precision, it is preferable to use a 茧 type/new type.

The content of the cerium oxide particles (i) is not limited. The content of the cerium oxide particles (i) is preferably 0.05% by weight or more and 0.5% by weight or less in the polishing composition (slurry) used for polishing.

The alkaline substance (ii) is capable of causing hydroxide ions of a polishing target such as a chemically polished silicon wafer to be generated in water. Further, it also contributes to the dispersion of the cerium oxide particles (i). From the viewpoint of obtaining such a function more stably, the alkaline substance (ii) is preferably dissolved in the composition.

Examples of the basic substance (ii) include ammonia, an organic amine compound, tetramethylammonium hydroxide, sodium hydroxide, and potassium hydroxide. Examples of the organic amine compound include, for example, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethanolamine, diisopropylethylamine, and ethylene. Amine, diethylenetriamine, triethylenetetramine, tris(2-aminoethyl)amine, N,N,N',N'-tetramethylethylenediamine, hexamethylenediamine, 1,4, 7-triazacyclononane, 1,4,7-trimethyl-1,4,7-triazacyclononane, 1,4-diazacyclooctane, hexahydropyrazine, and six Hydrogen pyridine. The alkaline substance (ii) may be composed of one of the above substances The composition may be composed of two or more types.

Among the basic substances (ii), ammonia, an organic amine compound, and tetramethylammonium hydroxide are preferred from the viewpoint of not containing an alkali metal ion, and ammonia is particularly preferable from the viewpoint of having an appropriate pKa.

The concentration of the basic substance (ii) depends on the pKa of the basic substance (ii) used and the content of the cerium (i). The concentration of the alkaline substance (ii) is preferably 40 times the concentration of the abrasive composition (slurry) used in the polishing, and is preferably a concentration of pH = 9.0 to 11.5 to be a concentration of pH = 10.0 to 11.0. For better.

The water-soluble synthetic polymer (iii) contributes to polishing by being adsorbed on the surface of a polishing target such as a tantalum wafer and producing a hydrophilic film or the like.

In the present specification, the "water-soluble synthetic polymer" is a water-soluble polymer which is not derived from a natural product (such as cellulose). However, in the range which does not inhibit the effect of the present invention, the additive (v) is not a negatively-derived water-soluble polymer derived from a natural substance which is soluble in cellulose such as hydroxyethylcellulose.

In the specific aspect 1 of the polishing composition of the present embodiment, the water-soluble synthetic polymer (iii) contains a constituent unit (1) having an oxygen-containing group and a carbonyl group. Such an oxygen-containing group is an alcoholic hydroxyl group, or a substituted or unsubstituted alkoxy group, a carbonyl-based ketone group, a carbonyl group constituting a part of an ester bond, or a carbonyl group constituting a part of a guanamine bond.

The unsubstituted alkoxy (-OAk) group may, for example, be an alkoxy group such as a methoxy group (-OCH ₃ ) or an ethoxy group (-OCH ₂ CH ₃ ). Here, "Ak" means a straight or branched alkyl group. The carbon number of the alkyl group is not limited. For example, an alkyl group having 1 to 22, 1 to 12, 1 to 6, or 1 to 4 carbon atoms can be cited.

The substituted alkoxy group (-OAk') means a group in which one or more carbons of the alkoxy group are substituted. Examples of the substituent group include a hydroxyl group, an alkoxy group (which may be substituted or unsubstituted), and a halogen. Here, "Ak'" is a linear, branched or substituted alkyl group. The carbon number of the alkyl group is not limited. For example, an alkyl group having 1 to 22, 1 to 12, 1 to 6, or 1 to 4 carbon atoms can be cited.

Examples of the substituted alkoxy group include a hydroxyalkoxy group such as a hydroxymethoxy group (-OCH ₂ OH) or a hydroxyethoxy group (-OCH ₂ CH ₂ OH). The substituted alkoxy group substituted by a plural number may, for example, be -OCH ₂ CH(OH)CH ₂ OH, -OCH(CH ₂ OH)CH ₂ OH, -OCH ₂ CH(CH ₃ )OH, and -OCH(CH) ₃ ) CH ₂ OH. One or more of the hydroxyl groups contained in the substituted alkoxy group may be further substituted with an alkoxy group (specific examples include, for example, a hydroxy-substituted alkoxy group).

The single system to which the constituent unit (1) is imparted is not particularly limited. An example of such a monomer is, for example, a monomer (α) containing a compound having an ethylenically unsaturated bond. Examples of the compound having an ethylenically unsaturated bond include (meth)acrylic acid, (meth)acrylic acid ester, (meth)acrylamide, N-substituted (meth)acrylamide, acrylonitrile, vinyl. Esters, vinyl decylamine, allyl alcohol, allylamine, allyl ester, allyl decylamine and styrene.

The monomer (α) may be a compound which may have both an oxygen-containing group and a carbonyl group, or may have no oxygen-containing group, no carbonyl group, or no such functional group. The monomer (α) which does not have an oxygen-containing group, does not have a carbonyl group, or does not have any of these functional groups is polymerized, and then a necessary functional group can be introduced.

The monomer (α) may be a reaction product obtained by reacting a compound having an ethylenically unsaturated bond and a hydroxyl group with a cyclic ether compound, or may be a substituted alkoxy group. In the present specification, the "cyclic ether compound" is a compound having a cyclic ether structure such as an epoxy group or an oxycyclobutane ring, and the structure is ring-opened to react with a hydroxyl group of the above compound. Typical examples of the cyclic ether compound include an epoxy compound of a compound having an epoxy group. The epoxy compound may have an epoxy group substituted. Preferred examples of such an epoxy compound include ethylene oxide, propylene oxide, and glycidyl alcohol.

The constituent unit (1) may be at least one unit containing the units (1A) to (1F) represented by the general formulae 1A to 1F.

In the above formulae 1A to 1F, X is a CH ₂ , NH or oxygen atom, preferably NH or an oxygen atom, more preferably NH. R ^{1 is} independently a hydrogen atom or a methyl group, respectively. R ^{2 is} independently a hydrogen atom, a hydroxyl group, a substituted or unsubstituted alkoxy group. M1 to m10 are each independently an integer of 1 to 6, preferably an integer of 1 to 3. At least one of R ^{2 in} each unit is a substituent other than a hydrogen atom.

The m1 R ² present in the unit (1A) represented by the formula 1A may be mutually different substituents. At least one of m1 of R ² is a substituent other than a hydrogen atom. Of the m1 of R ² , at least one of them is preferably a hydroxyl group or a substituted alkoxy group, and more preferably two or more hydroxyl groups.

The unit (1A) represented by the formula 1A is an integer of 3 to 6, and R ¹ is a methyl group or X is an oxygen atom.

The (m2 + m3 + 1) R ² present in the unit (1B) represented by the formula 1B may be a mutually different substituent. At least one of (m2 + m3 + 1) of R ² is a substituent other than a hydrogen atom. Of the (m2+m3+1) R ² groups, at least one of them is preferably a hydroxyl group or a substituted alkoxy group, and more preferably two or more hydroxyl groups.

The (m4+m5+m6) R ² present in the unit (1C) represented by the formula 1C may be each a different substituent. Among the R ² of (m4+m5+m6), at least one of them is a substituent other than a hydrogen atom. Of the (m4+m5+m6) R ² groups, at least one of them is preferably a hydroxyl group or a substituted alkoxy group, and more preferably two or more hydroxyl groups.

The (m7+m8) R ² in the unit (1D) represented by the formula 1D may be a substituent which is different from each other. At least one of (m7+m8) of R ² is a substituent other than a hydrogen atom. Among the (m7+m8) R ² ,

Preferably, at least one is a hydroxyl group or a substituted alkoxy group, and more preferably two or more hydroxyl groups are present.

There are m9 R ^{2 's} different substituents in the unit (1E) represented by the general formula 1E. At least one of m9 of R ² is a substituent other than a hydrogen atom. Of the m 9 R ² , preferably at least one is a hydroxyl group or a substituted alkoxy group, and more preferably two or more hydroxyl groups are present.

The m10 R ² present in the unit (1F) represented by the formula 1F may be different substituents. At least one of m10 of R ² is a substituent other than a hydrogen atom. Of the m10 R ² 's, at least one is preferably a hydroxyl group or a substituted alkoxy group, and more preferably two or more hydroxyl groups.

From the viewpoint of improving the hydrophilicity of the water-soluble polymer (iii), the units (1A) to (1F) represented by the general formulae 1A to 1F preferably have one or more hydroxyl groups, and have two or more hydroxyl groups. For better.

The unit (1A) can be obtained, for example, by polymerizing a monomer (α). The monomer (α) used herein may, for example, be N-(hydroxymethyl)propenylamine, N-(2-hydroxyethyl)acrylamide or (2,3-dihydroxypropyl)propene oxime. Amine, N-(hydroxymethyl)methacrylamide, N-(2-hydroxyethyl)methacrylamide, (2,3-dihydroxypropyl)methacrylamide, N-(hydroxyl Methyl) acrylate, N-(2-hydroxyethyl) acrylate, (2,3-dihydroxypropyl) acrylate, N-(hydroxymethyl) methacrylate, N-(2-hydroxyethyl) Methyl methacrylate, and (2,3-dihydroxypropyl) methacrylate.

The unit (1B) can be obtained, for example, by polymerizing a monomer (α). The monomer (α) used herein may, for example, be N-[bis(hydroxymethyl)methyl]acrylamide or (2-hydroxy-1-methylethyl)propenamide.

The unit (1C) can be obtained, for example, by polymerizing a monomer (α). The monomer (α) used herein may, for example, be N-[tris(hydroxymethyl)methyl]acrylamide.

The unit (1D) can be obtained, for example, by polymerizing a monomer (α). The monomer (α) used herein may, for example, be N,N-bis(hydroxymethyl)acrylamide or N,N-bis(hydroxyethyl)acrylamide.

The unit (1E) can be obtained, for example, by polymerizing a monomer (α). The monomer (α) used herein may, for example, be N-hydroxyethyl decyl vinylamine, N-hydroxypropyl decyl vinylamine, and N-(3-hydroxypropyl decyl) vinylamine, and five. Hydroxyhexyl vinylamine. Here, pentahydroxyhexyl vinylamine is obtained, for example, by reacting vinylamine with gluconolactone.

The unit (1F) can be obtained, for example, by polymerizing a monomer (α). The monomer (α) used herein may, for example, be N-hydroxyethyl allylamine, N-hydroxypropyl allylamine or N-(3-hydroxypropionyl)allylamine. , pentahydroxyhexylallylamine. Here, pentahydroxyhexylallylpropylamine can be obtained, for example, by reacting allylamine with gluconolactone.

In addition to the above, the units (1A) to (1F) can be synthesized by prepolymerizing an appropriate monomer to form a polymer, and then reacting the polymer with a suitable compound.

The units (1A) to (1C) can be obtained, for example, by reacting poly(meth)acrylic acid or poly(meth)acrylate with an alcohol having a suitable substituent or a primary amine.

The unit (1D) is obtained, for example, by reacting poly(meth)acrylic acid or poly(meth)acrylate with a secondary amine having an appropriate substituent.

The unit (1E) can be obtained by reacting a polyvinyl alcohol or a polyvinylamine with a carboxylic acid having a suitable substituent, a carboxylic acid anhydride, a carboxylic acid chloride, or a lactone.

The unit (1F) can also be obtained by reacting a polyallyl alcohol or a polyallylamine with a carboxylic acid having a suitable substituent, a carboxylic acid anhydride, a carboxylic acid chloride, or a lactone.

The water-soluble synthetic polymer (iii) may be a homopolymer or a copolymer. In other words, when the constituent unit (1) contains any one of the units (1A) to (1F), it may be a homopolymer composed of only the same unit, or may be composed of two or more different units. Copolymer. At the time of the copolymer, two or more different units may be contained in any ratio. It may further contain constituent units other than the constituent unit (1).

The water-soluble synthetic polymer (iii) may further have a structural unit (2) represented by the following formula 2.

In the above formula 2, q is an integer of 1 to 6, preferably an integer of 1 to 3. X is CH ₂ , NH or an oxygen atom. Z ¹ , Z ² , Z ³ , and Z ⁴ are each independently a hydrogen atom or a methyl group. Y ^- line anion. Examples of the anion group include chloride ion, bromide ion, iodide ion, nitrate ion, acetate ion, sulfate ion, phosphate ion, and hydroxide ion. The sulfate ion (SO ₄ ^2-), for the valence number of the anion is greater than 1, constituting the system unit (2) contained in it and Y ^- is in terms of the equivalent amount of a monovalent ion (ions when sulfate-based 1/2) by.

The cationic group in the above formula 2 is an amine group (ammonium group) of the first to fourth stages.

The method of obtaining the constituent unit (2) is not limited. For example, the constituent unit (2) is obtained by polymerizing the following compound as a monomer. When only the N-substituted acrylamide is exemplified, for example, N-(aminomethyl)acrylamide, N-(aminoethyl)acrylamide, N-(aminopropyl)acrylamide, N-(monomethylaminoethyl) acrylamide, N-(monomethylaminopropyl) acrylamide, N-(dimethylaminoethyl) acrylamide, N-(dimethyl Aminopropyl) acrylamide, (acrylamidoximeethyl)trimethylammonium salt and (acrylamidopropyl)trimethylammonium salt. Or a suitable compound (exemplified by acrylic acid, methacrylic acid, acrylate, methacrylate, acrylamide, and methacrylamide, and an inducer thereof) is polymerized to be ingested in a monomer After the polymer is allowed to react with an appropriate compound, a 1st to a fourth amine group (ammonium group) is introduced to construct the constituent unit (2).

Since the constituent unit (2) has a cationic group and the polishing target is a tantalum wafer, the wafer is negatively charged during polishing, so that the water-soluble polymer (iii) is adsorbed on the tantalum wafer, and is expected to be on the tantalum wafer. It is easy to form a protective film based on the water-soluble polymer (iii).

In the specific aspect 2 of the polishing composition of the present embodiment, the water-soluble synthetic polymer (iii) may be one of the water-soluble synthetic polymer (iii) and the epoxy compound of the above aspect 1. Cyclic ether combination The reactant obtained by the reaction. When an epoxy compound is used as a specific example, ethylene oxide and glycidyl alcohol are used to enhance the hydrophilicity, and propylene oxide is expected to improve the water repellency and improve the adsorption property to the wafer. In the second aspect, it is particularly preferred to use glycidol.

The structure of the terminal of the water-soluble synthetic polymer (iii) of the present embodiment is not particularly limited. For the purpose of controlling the molecular weight, a known chain transfer agent is used which constitutes the end structure. From the viewpoint of introducing a hydroxyl group from the terminal, preferred examples of the chain transfer agent include isopropyl alcohol, glycerin, and thioglycerol.

The constituent unit of the water-soluble synthetic polymer (iii) of the present embodiment may contain a known constituent unit in addition to the above-described various properties, or the adjustment of hydrophilicity/hydrophobicity. For example, a structural unit having a structure obtained by polymerization of the following monomers can be mentioned (of course, the reaction is further carried out after polymerization of other monomers, and as a result, the same structural unit can be obtained.): Acrylamide, N-A Acrylamide, N-isopropylacrylamide, N-alkyl acrylamide, N,N-dimethyl decylamine, N,N-dialkyl acrylamide, propylene methoxy morphine , N-(trimethoxydecylalkyl) acrylamide, acrylic acid, methyl acrylate, ethyl acrylate, alkyl acrylate, trimethoxydecylalkyl acrylate, vinyl ester (vinyl alcohol), ethylene Base amine (vinylamine), N-alkylmercapto vinylamine, N-monoalkyl vinylamine, N,N-dialkylvinylamine, allylamine, N-alkylmercaptopropene Amine, N-monoalkylallylamine, N,N-dialkylallylamine, vinylpyrrolidone, oxazoline, alkyloxazoline, vinylimidazole, vinylpyridine (ethylene Pyridine N-oxide), styrene, and hydroxystyrene.

The polymerization method of the monomer which can provide the structural unit contained in the water-soluble polymer (iii), such as a structural unit (1) and a structural unit (2) is not limited. The polymerization can be carried out by a conventionally known method.

The molar fraction of the constituent unit (1) is not particularly limited with respect to the entire constituent unit of the water-soluble synthetic polymer (iii) of the present embodiment. From the viewpoint of hydrophilicity, it is preferably 50 mol% or more, more preferably 70 mol% or more, and most preferably 80 mol% or more.

The molar fraction of the constituent unit (2) is not particularly limited with respect to the entire constituent unit of the water-soluble synthetic polymer (iii) of the aspect 2. From the viewpoint of moderately suppressing the aggregation of cerium oxide, the molar fraction of the constituent unit (2) is preferably less than 50 mol%, more preferably 0.01 mol% or more and 10 mol% or less. In order to more stably suppress the aggregation of cerium oxide, the molar fraction of the constituent unit (2) can be set to 0.01 mol% or more and 5 mol% or less. When the polishing target is a germanium wafer, the molar fraction of the constituent unit (2) can be made 0.01 mol% or more and 2 mol% or less from the viewpoint of reducing the haze of the polished wafer.

The molecular weight of the water-soluble synthetic polymer (iii) of the present embodiment is not limited. From the viewpoint of being adsorbed on the surface of the polishing target such as a tantalum wafer and obtaining a protective film having an appropriate strength, the weight average molecular weight (Mw) is preferably 1,000 or more. From the viewpoint of obtaining a stronger protective film, the weight average molecular weight (Mw) is preferably 5,000 or more. In order to obtain a stronger protective film, the weight average molecular weight (Mw) is preferably 10,000 or more. On the other hand, if the weight average molecular weight (Mw) is too large, it is possible to excessively promote the aggregation of cerium oxide, or it is difficult to remove the protective film in the water washing after the grinding. Therefore, The molecular weight of the water-soluble synthetic polymer (iii) of the present embodiment is preferably 5,000,000 or less in terms of weight average molecular weight (Mw). When the weight average molecular weight (Mw) is large, the protective film formed of the water-soluble synthetic polymer (iii) may have a structure having many voids. From the viewpoint of forming such a protective film to be more stably lowered, it is preferably 1,000,000 or less.

The concentration of the water-soluble synthetic polymer (iii) of the present embodiment is preferably 10 ppm or more and 1000 ppm or less in the polishing composition (slurry) used for polishing. Among them, it is preferably 20 ppm or more and 750 ppm or less.

In the abrasive composition of the present embodiment, water (iv) has a function of dissolving or dispersing other components. In order to prevent the action of other contained components from being hindered, it is preferred that the amount of impurities contained in the water (iv) is small. Specifically, it is preferred to use distilled water, ion exchange water, ultrapure water or the like. The amount of water (iv) in the abrasive composition is the residual amount relative to the concentration or amount of other ingredients in the abrasive composition.

The abrasive composition of the present embodiment may further contain an added (v). For example, the adjustment of various properties of the slurry, the metal ion trapping, the water-soluble synthetic polymer (iii) may be added to the object to be polished (specific examples may be exemplified by the adsorption of the wafer), or other purposes. Specifically, one or more additives may be added from, for example, an alcohol, a chelating agent, and a nonionic surfactant. Examples of the alcohols include methanol, ethanol, propanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, glycerin, polyethylene glycol, and polypropylene glycol. Examples of the chelating agent include, for example, Amine tetraacetic acid (EDTA), nitrotriacetic acid (NTA), hydroxyethylenediaminetetraacetic acid, propylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetramine hexaacetic acid, and ammonium salts and sodium thereof a metal salt such as a salt or a potassium salt. Examples of the nonionic surfactant include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkenyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene alkyl ether, alkyl poly Glycosides, and polyethers modify polyoxo.

The method for producing the abrasive composition of the present embodiment is not limited. A conventionally known method can be used. For example, the abrasive composition of the present embodiment can be obtained by mixing cerium oxide particles (i), a basic substance (ii), a water-soluble synthetic polymer (iii), and water (iv).

The specific aspect of the polishing composition of the present embodiment is an abrasive composition for a tantalum wafer containing the abrasive composition described in any of the above aspects 1 and 2.

The abrasive composition for a wafer can be obtained by mixing cerium oxide particles (i), a basic substance (ii), a water-soluble synthetic polymer (iii), and water (iv). The resulting abrasive wafer composition can be used for final polishing applications such as wafers in semiconductor device fabrication processes.

The specific aspect 4 of the abrasive composition of the present embodiment relates to the manufacture of a tantalum wafer product including the step of polishing the tantalum wafer using the abrasive composition described in any of the above aspects 1 and 2 method. In the present specification, the term "矽 wafer product" means a step of polishing a silicon wafer by using the abrasive composition described in any of the above aspects 1 and 2. Such a step can be introduced as a polishing step for the germanium wafer, and it is particularly preferred to introduce the final polishing step as a germanium wafer.

The abbreviations used in this specification are as follows.

HEAA: N-(2-hydroxyethyl) acrylamide

TMAPAA: chlorinated (3-acrylamidaminopropyl) trimethylammonium

DHPMA: a mixture of (2,3-dihydroxypropyl)methacrylate and bis(hydroxymethyl)methyl methacrylate (about 75 mol%: about 25 mol%)

THMMAA: N-[tris(hydroxymethyl)methyl]propenylamine

HPAA: N-(3-hydroxypropyl) acrylamide

DHPAA: N-(2,3-dihydroxypropyl) acrylamide

HEMAA: N-(2-hydroxyethyl)methacrylamide

DHPMAA: N-(2,3-dihydroxypropyl)methacrylamide

HEAA-GO _0.25 : N-(2-hydroxyethyl) acrylamide-glycidyl alcohol adduct

PAA: poly(acrylamide)

PHEOVE: Poly(hydroxyethyl oxyethyl vinyl ether)

PVA: polyvinyl alcohol

PVP: poly(vinylpyrrolidone)

PPEI: poly(N-propionyl extended ethyl imine)

The embodiments described above are intended to facilitate the understanding of the present invention and are not intended to limit the invention. Therefore, the various elements disclosed in the above-described embodiments are intended to include all design changes and equivalents of the scope of the invention.

(Example)

Hereinafter, the present invention will be specifically described in the examples, but the present invention is not limited to the following examples.

Examples 1 to 8, Reference Example 1, and Comparative Examples 1 to 5 <Preparation of monomers>

DHPMA was synthesized from glycidyl methacrylate manufactured by Aldrich Co., Ltd. as described in the literature (SHaw et al., Polymer 47, 8247-8252, 2006). According to the literature, a mixture of (2,3-dihydroxypropyl)methacrylate and bis(hydroxymethyl)methyl methacrylate (about 75 mol%: about 25 mol%) was produced. The results of the product were confirmed by GPC measurement, and the two peaks were observed at an area ratio of 75:25.

The company that obtained the monomer other than the following is as follows.

HEAA: Tokyo Chemical Industry Co., Ltd.

TMAPAA: Tokyo Chemical Industry Co., Ltd.

THMMAA: Aldrich

AA: Tokyo Chemical Industry Co., Ltd.

<Synthesis of water-soluble synthetic polymer>

The water-soluble synthetic polymers of Examples 1 to 8 and Comparative Example 1 were synthesized in the following manner.

While maintaining a nitrogen peroxide solution, an ammonium persulfate solution (1.6 g (7.0 mmol) of ammonium persulfate, and 1000 g of pure water) at 70 ° C, 1.0 mol of the monomer was dropped in about 2 hours (the total monomer mass when the copolymer was copolymerized) The sum is 1.0 mol) and a solution of 960 g of pure water. After completion of the dropwise addition, the mixture was further stirred at 70 ° C for 1 hour, and then cooled to room temperature. Then, in order to remove unreacted monomers, the reaction was dropped into acetone having a capacity of 5 times. Take out the precipitate formed by decantation, and double the capacity. After washing with acetone, it was dried under vacuum.

Examples 2 and 3 are copolymers composed of HEAA and TMAPAA, Examples 5 and 6 are copolymers composed of HEAA and DHPMA, and Example 8 is a copolymer composed of HEAA and THMAA. The feed ratio (molar ratio) of each monomer is shown in Table 1.

The HEC of Reference Example 1 was obtained from Daicel Fine CHem Co., Ltd., and the PEG was obtained from Wako Pure Chemical Industries Co., Ltd.

The PVA of Comparative Example 2 was obtained from Wako Pure Chemical Industries Co., Ltd., and the PHEOEVE of Comparative Example 3 was obtained from Maruzen Petrochemical Company.

The PVP of Comparative Example 4 and the PPEI of Comparative Example 5 were obtained from Aldrich Co., Ltd.

Example 9 <Synthesis of polyHPAA>

After 0.020 g of APS was added to a mixture of 2.15 g of methyl acrylate (MA) and 8.58 g of methanol, the polymerization was carried out under nitrogen at 65 ° C for 10 hours. Thereafter, the reaction liquid was cooled to room temperature, and the resulting precipitate was taken out by decantation to obtain a polymethyl acrylate solid (yield: 97%). The obtained polymethyl acrylate solid was further added to 8.58 g of methanol, and heated at 65 ° C for 10 minutes, and then cooled to room temperature, and the supernatant was removed to remove unreacted monomers.

To the obtained polymethyl acrylate, 5.63 g of 3-aminopropanol and 0.082 g of a 28% NaOMe methanol solution were added, and the amide amination reaction was carried out at 100 ° C for 20 hours. After the completion of the reaction, the reaction liquid was added dropwise to acetone (25 g) after adding 3.3 g of methanol. The solid formed is separated from the supernatant by decantation, and further The procedure was washed with acetone 15 g, and dried at 40 ° C for 1 hour under vacuum. After drying, it was dissolved in 30 g of pure water, and then filtered through a 3 μm filter. After sampling the filtrate for several g, the polymer concentration is determined by the drying method, and then pure water is added in an appropriate amount to form a polyHPAA 5% aqueous solution (yield 80%).

Example 10 <Synthesis of polyDHPAA>

From the synthesis of polyHPAA, a polyDHPAA 5% aqueous solution was obtained in the same manner except that 3-aminopropanol was substituted with 6.83 g of 3-amino-1,2-propanediol (yield 75%).

Example 11 <Preparation of monomers>

To ice-cold methyl methacrylate (MMA) 10.0 g, 0.984 g of a 28% NaOMe methanol solution was added dropwise. Then, it was ice-cooled, and 6.72 g of 2-aminoethanol was added dropwise over 30 minutes. At this time, be careful not to allow the liquid temperature of the reaction liquid to exceed 30 °C. After further reacting at room temperature for one night, 25 g of pure water and 8.8 mL of a cation exchange resin (Organo Co., Ltd. 200 CTHAG) were added, and the reaction liquid was neutralized. The cation exchange resin was filtered off through a 1 μm filter to obtain an aqueous HEMAA monomer solution. After sampling a few g from the solution and quantifying the monomer concentration by a dry method, an appropriate amount of pure water was added to form a 20% aqueous solution of HEMAA monomer (yield 68%).

<Synthesis of polyHEMAA>

8.40g of HEMAA aqueous solution obtained above and 8.30g of pure water After adding 0.10 g of a 10% APS aqueous solution to the mixed solution, the polymerization was carried out at 65 ° C under 10 nitrogen conditions. After the termination of the polymerization, the reaction cooled to room temperature was dropped into 30 g of acetone to obtain a polyHEMAA solid. The obtained solid was further washed with 15 g of acetone, and then vacuum dried at 40 ° C for 1 hour. The vacuum-dried solid was dissolved in 30 g of pure water, and then filtered through a 3 μm filter. After sampling a few g from the solution, the polymer concentration is quantified by the drying method, and an appropriate amount of pure water is added to finally obtain a 5% polyHEMAA aqueous solution (yield 74%).

Example 12 <Preparation of monomers>

From the monomer synthesis of polyHEMAA, a 10% DHPMAA monomer aqueous solution was obtained in the same manner except that 2-aminoethanol was substituted with 10.00 g of 3-amino-1,2-propanediol (yield 90%).

<Synthesis of polyDHPMAA>

From the synthesis of the polymer of polyHEMAA, an aqueous solution of 5% polyDHPMAA was obtained in the same manner except that the aqueous solution of HEMAA was substituted with 8.40 g of an aqueous DHPMAA solution (yield 77%).

Example 13 <Preparation of monomer (HEAA: GO = 1: 0.25 mol/mol)>

0.16 g of glycidol was dropped into the mixture of 1.00 g of HEAA monomer heated to 70 ° C and 0.0025 g of N,N'-tetramethylethylenediamine (TEMED) for about 1 hour. After the completion of the dropwise addition, the mixture was further maintained at 70 ° C for 10 minutes, and then returned to room temperature.

<poly(HEAA-GO _0.25 ) synthesis>

21.9 g of pure water and 0.14 g of a 10% APS aqueous solution were added to the above reaction liquid, and polymerization was carried out under nitrogen conditions at 65 ° C for 10 hours. After the termination of the polymerization, a 3 μm filter was filtered. The resulting solution was considered to be a 5.0% solution of poly(HEAA-GO _0.25 ) for use in the preparation of various experimental solutions/slurry.

<Molecular weight and molecular weight distribution>

The number average molecular weight (Mn) and the weight average molecular weight (Mw) of the water-soluble synthetic polymers of Examples 1 to 13, Reference Example 1, and Comparative Examples 1 to 5 were measured by GPC measurement. The conditions measured by GPC are as follows. The values of the respective molecular weights are shown in Table 1.

GPC device: SCL-10A manufactured by Shimadzu Corporation

Pipe column: TSKgel GMPW _XL (×1) + TSKgel G2500PW _XL (×1) manufactured by Tosoh

Lysate: 0.1mol/kg NaCl, 20% methanol, the rest is pure water

Flow rate: 0.6mL/min

Detection method: RI+UV (254nm)

Standard material: polyethylene oxide

<Wetability test: water-soluble synthetic polymer>

The 1 inch wafer was immersed in 1% hydrofluoric acid for 2 minutes to remove the oxide film on the surface. After confirming that the surface is fully water-repellent (wetability 0%), the wafer is implemented. Each of the water-soluble synthetic polymer 4000 ppm aqueous solutions (Reference Example 1 HEC 3600 ppm, PEG 400 ppm) of Examples 1 to 13, Reference Example 1 and Comparative Examples 1 to 5 was immersed for 10 minutes. After 10 minutes, the wafer was taken out, and water was gently added to confirm the wettability of the surface. Here, the wettability is expressed as a percentage of the ratio of the area wetted by the wafer surface to the whole. The results are shown in Table 1.

<Preparation of abrasive composition (slurry)>

The abrasive composition is a slurry of cerium oxide particles prepared by the method described in Patent No. 4,712,556 (the particle diameter measured by the BET method is 17.8 nm; the particle diameter D50 = 30.7 nm, SD = 10.0 measured by dynamic light scattering method). Nm), ammonia water (manufactured by Kanto Chemical Co., Ltd.), an aqueous solution of a water-soluble polymer, and ion-exchanged water are prepared.

<Grinding speed and wettability after grinding: abrasive composition>

The polishing was carried out under the following conditions, and the polishing rate was determined from the change in weight of the wafer before and after the polishing. For the wafer after the grinding, the surface wettability was confirmed after gently adding water to the surface. The results are shown in Table 1.

The composition of the abrasive composition is 1125 ppm of cerium oxide, 100 ppm of ammonia, and 100 ppm of water-soluble synthetic polymer (reference example 1 is HEC 90 ppm, PEG 10 ppm)

Grinding machine: LGP-15S-I manufactured by Micro Technology Co., Ltd.

Wafer: 4 inch wafer

(P type, resistivity 5 to 18 mΩ/Cm, crystal plane orientation <111>)

Surface pressure: 0.25kgf/cm ²

Wafer rotation speed: 100rpm

Gasket: SURFIN SSWI made by Fujimi

Gasket rotation speed: 30rpm

Grinding slurry supply speed: 100mL / min

Grinding time: 10 minutes

Note: In the cell of the water-soluble polymer/molecular weight/MN and Mw of Reference Example 1, the upper part indicates the molecular weight of HEC and the lower part indicates the molecular weight of PEG.

As is apparent from Table 1, in all of the results of Examples 1 to 13, it was confirmed that the wettability of the surface of the wafer after polishing was high.

<LPD evaluation>

Next, in the manufacturing process of the wafer for the product, the above-mentioned polishing liquid containing various water-soluble polymers is used as the polishing liquid for finishing polishing, and the LPD (Light Point Defect) observed on the surface of the wafer after the polishing is evaluated. )density.

Specifically, the following experiments were carried out.

A double-sided polished 矽 wafer wafer having a diameter of 300 mm was prepared as a sample wafer for finishing polishing test. A one-side mirror polishing (CMP) apparatus (not shown) was used to remove the surface polishing treatment by 1 μm on the surface of each sample wafer to remove the processing damage on the surface of each sample wafer. Thereafter, the polishing liquid of the 5-level polishing composition shown in Table 2 was used as the final finishing single-side polishing treatment, and the surface of each sample wafer was subjected to finishing polishing. The finishing grinding treatment conditions are all the same conditions, specifically, the single-sided mirror polishing shown in FIG. 1 is used to make the abrasive cloth 3 made of Suede adhered to the polishing base 2 The sample wafers 5 held by the head 4 are rotated with each other, and the polishing liquid is supplied from the polishing liquid supply nozzle 1 at about 500 ml/min, and the single-side grinding is performed under the conditions of a polishing pressure of 125 g/cm ² and a polishing time of 300 seconds. deal with. The blending of the abrasive composition (slurry) was the same as in Examples 1 to 13 except for the water-soluble polymer used and the concentration of each component.

The water-soluble synthetic polymer of Example 14 was prepared using the same polyHEAA as in Example 1 and the water-soluble synthetic polymer of Example 15 using the same polyHEMAA as in Example 11 and the water-soluble synthetic polymer of Example 16. In the same manner as the poly(HEAA-GO _0.25 ) of Example 13, the water-soluble synthetic polymer of Comparative Example 6 was the same as that of Comparative Example 1, and the water-soluble synthetic polymer of Reference Example 2 was the same as that of Reference Example 1. +PEG.

After the RCA was cleaned by each of the sample wafers subjected to the finishing polishing, a surface defect inspection device (Surfscan SP-2 manufactured by KLA-Tencor Co., Ltd.) was used to measure the LPD density of 35 nm or more observed on the surface of each sample wafer. . The LPD results shown in Table 2 are the average values of the measurement results of the six sample wafers subjected to the finishing polishing, and the relative values of the reference example 1 are set to 100.

As is apparent from Table 2, Examples 14 to 16 are defects in which the LPD density is low. On the other hand, in the sample of Comparative Example 6, the number of detection points of the sample wafer was too large to overflow the data, and measurement was impossible.

(industrial use possibility)

The abrasive composition of the present invention, the abrasive composition for a tantalum wafer, and the method for producing a tantalum wafer product are useful for stably supplying high quality surface characteristics (low residual particles/low LPD).矽 Wafer.

1‧‧‧ polishing liquid supply nozzle

2‧‧‧grinding base plate

3‧‧‧ polishing cloth

4‧‧‧ polishing head

5‧‧‧Sample Wafer

Claims (11)

An abrasive composition comprising cerium oxide particles, a basic substance, a water-soluble synthetic polymer, and a polishing composition for water, characterized in that the alkaline substance is ammonia, an organic amine compound, or a hydroxide At least one of tetramethylammonium, sodium hydroxide, and potassium hydroxide, wherein the water-soluble synthetic polymer has a structural unit (1), and the structural unit (1) has an oxygen-containing group and a carbonyl group, and is derived from a monomer (α) which is a reactant obtained by reacting a compound having an ethylenically unsaturated bond and a hydroxyl group with an epoxy compound, and has a substituted alkoxy group, and the oxygen-containing group is an alcoholic hydroxyl group. Or a substituted or unsubstituted alkoxy group, a carbonyl group-containing ketone group, a carbonyl group constituting a part of an ester bond, or a carbonyl group constituting a part of a guanamine bond, and the above-mentioned structural unit (1) contains the formulas 1A to 1F. At least one of the units (1A) to (1F); In the above formulae 1A to 1F, X is CH ₂ , NH or an oxygen atom; R ^{1 is} each independently a hydrogen atom or a methyl group; and R ^{2 is} independently a hydrogen atom, a hydroxyl group, or a substituted or unsubstituted alkoxy group; M1 to m10 are each independently an integer of 1 to 6; and at least one of R ^{2 in} each unit is a substituent other than a hydrogen atom. The abrasive composition according to claim 1, wherein the units (1A) to (1F) represented by the above formulas 1A to 1F each have one or more hydroxyl groups. The abrasive composition according to claim 1, wherein the units (1A) to (1F) represented by the above formulas 1A to 1F each have two or more hydroxyl groups. The abrasive composition according to any one of claims 1 to 3, wherein, in the above formulae 1A, 1B, 1C, 1E, and 1F, X is NH or an oxygen atom. The abrasive composition according to any one of the first to third aspects of the present invention, wherein the constituent unit (1) has a molar fraction of 50 mol with respect to the entire constituent unit of the water-soluble synthetic polymer. More than 8% of the ear. The abrasive composition according to any one of claims 1 to 3, wherein the water-soluble synthetic polymer further has a structural unit (2) represented by the following formula 2, In Formula 2, q is an integer of 1 to 6, X is CH ₂ , NH or an oxygen atom, and Z ¹ , Z ² , Z ³ and Z ⁴ are each independently a hydrogen atom or a methyl group, and a Y ^- based anion. An abrasive composition as described in claim 6, wherein The molar fraction of the constituent unit (2) is less than 50 mol% with respect to the entire constituent unit of the water-soluble synthetic polymer. An abrasive composition comprising cerium oxide particles, a basic substance, a water-soluble synthetic polymer, and an abrasive composition of water, wherein the alkaline substance is ammonia, an organic amine compound, tetramethyl hydroxide And a water-soluble synthetic polymer according to any one of claims 1 to 7 which is obtained by reacting at least one of ammonium hydroxide, sodium hydroxide and potassium hydroxide, wherein the water-soluble synthetic polymer according to any one of claims 1 to 7 is reacted with an epoxy compound. The reactants. The abrasive composition according to any one of claims 1 to 3, wherein the cerium oxide particles are prepared by using alkoxysilane or a condensate thereof as a raw material, and having a primary particle diameter of 10 To 40nm, and The secondary particle diameter is 20 to 80 nm. An abrasive composition for a tantalum wafer, which comprises the abrasive composition according to any one of claims 1 to 9. A method of producing a tantalum wafer product, comprising the step of grinding a tantalum wafer using the abrasive composition according to any one of claims 1 to 9.