KR20100137537A - Colloidal silica with modified surface and polishing composition for cmp containing the same - Google Patents

Abstract

This invention is surface modified colloidal silica characterized by surface modification by at least 1 group represented by following General formula (1), (2), and (3), and CMP polishing composition containing this. According to the present invention, in the first stage polishing in CMP polishing, there is no polishing residue while suppressing deterioration of dishing, and in the second stage polishing, there is provided a polishing composition for CMP which can improve the shaping phenomenon. can do.

Description

Surface modified colloidal silica and polishing composition for CMP containing the same {COLLOIDAL SILICA WITH MODIFIED SURFACE AND POLISHING COMPOSITION FOR CMP CONTAINING THE SAME}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to surface modified colloidal silica and a polishing composition for CMP (Chemical Mechanical Polishing) containing the same. It relates to a polishing composition for CMP.

In the CMP technique, a flattening wafer is placed on a rotating plate, the pad is brought into contact with the surface of the wafer, and both the rotating disk and the pad are rotated while polishing while feeding the polishing composition between the wafer and the pad. The surface of the polished object is polished by the mechanical action of the polishing particles and the pad surface in the polishing composition for CMP, and at the same time, the wafer surface is planarized by a chemical reaction between the compound and the surface of the polishing compound in the polishing composition for CMP.

In the manufacture of a semiconductor device, when forming a wiring by the damascene method, CMP is performed to remove the excess wiring layer and the barrier metal layer. In this CMP, in the two-step polishing method frequently performed, the wiring layer of the outermost layer portion is removed by polishing in the first stage polishing, and the wiring layer, barrier metal layer, and insulating layer remaining in the first stage polishing in the second stage polishing. The method of grinding | polishing and flattening the surface is used.

In CMP, to provide a flat polishing surface that suppresses dishing, corrosion, and the like, and polishing residues It is demanded to provide a nonexistent, providing a polishing surface with reduced scratches, and providing a sufficient polishing rate at which no problem occurs in productivity. In the case of the first stage polishing, a selective polishing which effectively removes a wiring layer made of copper-based materials such as copper and a copper alloy and extremely suppresses polishing of the barrier metal layer made of tantalum-based materials such as tantalum and tantalum nitride In the case of the second stage polishing, non-selective polishing with a small difference in polishing rate with respect to other materials of the insulating layer made of a silica-based material such as a wiring material, a barrier metal layer, silica, and organic silica is required.

As polishing particles used in the polishing composition for CMP, silica which has been surface-modified with an organic group has been studied. For example, Patent Document 1 discloses using a surface-modified silica as a CMP slurry from a removal rate modifier represented by a dimethylsilanol group, and as a compound introducing a dimethylsilanol group, dimethyldichlorosilane is disclosed. have. In addition, Patent Document 2 discloses a colloidal silica surface-modified with an aminosilane coupling agent. In addition, Patent Document 3 discloses a polishing composition for CMP containing silane-modified polishing particles in which a metal oxide abrasive having a surface metal hydroxide and a silane compound having a non-hydrolyzable substituent are combined.

The polishing composition for CMP is designed to satisfy the required characteristics by the combination of the selection and blending of various components such as abrasive particles and an oxidizing agent, but there is still room for improvement for various required performances. In particular, in the first stage polishing, it was difficult to solve the polishing residue while suppressing dishing due to the mechanism of the CMP. That is, although it is effective to raise a grinding | polishing inhibitory effect in suppressing dishing, when a grinding | polishing inhibitory effect is raised, it will become easy to produce the grinding | polishing residue of a to-be-grinded object. In the second stage polishing, the barrier metal layer and the insulating layer are excessively polished at the boundary portion between the wiring layer, the barrier metal layer and the insulating layer, and the shaping phenomenon in which the barrier metal layer and the insulating layer retreat inward relative to the wiring layer surface. There is a problem that (fang) occurs.

Patent Document 1: Japanese Patent Application Laid-Open No. 2004-534396 Patent Document 2: Japanese Patent Application Laid-Open No. 2007-273910 Patent Document 3: Japanese Patent Application Laid-Open No. 2007-088499

SUMMARY OF THE INVENTION An object of the present invention is to provide a polishing composition for CMP without polishing residues while suppressing deterioration of dishing in the first stage polishing in CMP polishing, in particular, copper-based wiring formation by the damascene method. . Moreover, in 2nd stage grinding | polishing, it is a subject to provide the polishing composition for CMP which can improve shaping | phenomena.

MEANS TO SOLVE THE PROBLEM As a result of earnestly researching in order to solve the said subject, the present inventors discovered that the colloidal silica which performed the specific surface modification was effective for solving the said subject, and resulted in this invention. That is, this invention provides the surface modified colloidal silica characterized by surface modification by at least 1 group represented by following General formula (1), (2), and (3).

(In formula, A <^1> represents group chosen from following formula (a11)-(a13), (a31)-(a33) and (a51)-(a53), and A <^2> represents following formula (a21)-(a23) ), (a41) to (a43) and (a61) to (a63), R ³ represents a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, Y represents A ² or R ³ , and EO Represents an ethylene oxide group, PO represents a propylene oxide group, m, n, and p represent a number where m is 0 to 170, n is 0 to 120, p is 0 to 170, and m + p is not O. )

(In formula, R <^1> , R <^2> represents a C1-C4 alkyl group, a phenyl group, or a hydroxyl group, X represents a C1-C18 alkylene group, and R represents a hydrogen atom or a methyl group.)

Moreover, this invention provides the polishing composition for CMP characterized by containing said surface modified colloidal silica.

According to the present invention, it is possible to provide a polishing composition for CMP that controls dishing and has no polishing residues in CMP, especially CMP when copper wiring is formed by the damascene method. Further, in the second stage polishing, it is possible to provide a polishing composition for CMP that can improve the chipping phenomenon.

First, the surface modified colloidal silica of this invention is demonstrated.

In the surface modified colloidal silica of the present invention, the silanol groups present on the surface of the colloidal silica become reaction sites and form siloxane bonds with the surface modifier compound. ) Or (3), or may be modified with at least two groups selected from the general formulas (1), (2) and (3). The groups represented by the general formulas (a11), (a21), (a31), (a41), (a51) and (a61) are formed by reacting with one silanol group present on the surface of colloidal silica. The surface modifier compound having at least one group represented by General Formula (1), (2) or (3) is bonded to silicon on colloidal silica to form a siloxane bond.

The groups represented by the general formulas (a12), (a22), (a32), (a42), (a 52) and (a62) react with two silanol groups present on the surface of colloidal silica and a surface modifier compound. The group represented by the general formulas (a13), (a23), (a33), (a43), (a53) and (a63) is formed of three silanol groups and surface modifier compounds present on the surface of colloidal silica. This reaction is formed. In addition, the surface modified colloidal silica of this invention may be surface-modified by groups other than group represented by the said General formula (1), (2) or (3). In the case where the surface modifier is represented by the general formula (1) or (3), the terminal silyloxy group may be bonded to the same colloidal silica particles, or may be combined with other colloidal silica particles to form colloidal silica particles. You may crosslink. Whether or not the colloidal silica is non-crosslinked or crosslinked can be selected depending on the concentration and reaction conditions of the colloidal silica, which is a modifier, and the modifier compound for introducing the surface modifier. When the surface-modified colloidal silica of the present invention is used as the abrasive grain of the polishing composition for CMP, when a crosslinked product is used, the particle diameter of the colloidal silica increases due to crosslinking, and the particle size distribution becomes uneven. Throw it away. Therefore, since the said crosslinked material worsens the dispersion stability of the polishing composition for CMP, use of a crosslinked material is not preferable.

(A11), (a12), (a13), (a21), (a22), (a23), (a31), (a32), in the group represented by the general formulas (1), (2) or (3). carbon number 1 represented by R ¹ and R ² of (a33), (a41), (a42), (a43), (a51), (a52), (a53), (a61), (a62) and (a63) Examples of the alkyl group of -4 include methyl, ethyl, propyl, 2-propyl, butyl, second butyl, isobutyl, and third butyl. The alkylene group having 1 to 18 carbon atoms represented by X may be linear and branched. It may be sufficient and may contain an alicyclic group. Specifically, methylene, ethylene, propylene, methyl ethylene, butylene, 1-methylpropylene, 2-methylpropylene, 1,2-dimethylpropylene, 1,3-dimethylpropylene, 1-methylbutylene, 2-methylbutyl Ethylene, 3-methylbutylene, 2,4-dimethylbutylene, 1,3-dimethylbutylene, pentylene, hexylene, heptylene, octylene, ethane-1,1-diyl, propane-2,2- Diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1 , 15-diyl, hexadecane-1,16-diyl, heptadecan-1,17-diyl, octadecane-1,18-diyl, cyclopentane-1,2-diyl, cyclopentane-1,3-diyl, Cyclohexane-1,1-diyl, cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl, methylcyclohexane-1,4-diyl, cyclohexane-1 , 4-dimethylene and the like. Examples of the hydrocarbon group having 1 to 30 carbon atoms represented by R ³ include methyl, ethyl, propyl, isopropyl, butyl, second butyl, third butyl, isobutyl, amyl, isoamyl, third amyl, hexyl, Cyclohexyl, cyclohexylmethyl, 2-cyclohexylethyl, heptyl, isoheptyl, third heptyl, n-octyl, isooctyl, tertiary octyl, 2-ethylhexyl, nonyl, isononyl, decyl, dodecyl, tridecyl Alkyl groups such as tetradecyl, pentadecyl, hexadecyl, heptadecyl and octadecyl; Vinyl, 1-methylethenyl, 2-methylethenyl, propenyl, butenyl, isobutenyl, pentenyl, hexenyl, heptenyl, octenyl, decenyl, pentadecenyl, 1-phenylpropene-3- Alkenyl groups such as one; Phenyl, naphthyl, 2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-vinylphenyl, 3-isopropylphenyl, 4-isopropylphenyl, 4-butylphenyl, 4-isobutylphenyl, 4-tertbutyl Phenyl, 4-hexylphenyl, 4-cyclohexylphenyl, 4-octylphenyl, 4- (2-ethylhexyl) phenyl, 4-stearylphenyl, 2,3-dimethylphenyl, 2,4-dimethylphenyl, 2, Alkyl aryl groups, such as 5-dimethylphenyl, 2, 6- dimethylphenyl, 3, 4- dimethylphenyl, 3, 5- dimethylphenyl, 2, 4- di- tert butylphenyl, and cyclohexylphenyl; And arylalkyl groups such as benzyl, phenethyl, 2-phenylpropan-2-yl, diphenylmethyl, triphenylmethyl, styryl and cinnamil.

In the group represented by the general formula (1), (2) or (3), if m + p is a value of n or more, the dispersion stability of the surface-modified colloidal silica in the polishing composition for CMP is good, and the polishing composition for CMP Since it is easy to control the performance by the compounding quantity of surface modified colloidal silica in the inside, since m | p is small, dishing may become large, and m + p is large, and a polishing residue may generate | occur | produce m +, It is preferable that it is 2-340, and, as for p, it is more preferable that it is 2-250.

In addition, in group represented by the said General formula (2) or (3), when R <^3> has large hydrophobicity, the dispersion stability of surface modified colloidal silica in the CMP polishing composition may worsen, and dishing becomes large. In some cases. As a preferable group of R <^{3>, it} is a C1-C8 alkyl group, and a methyl group is more preferable.

In the group represented by the general formulas (1), (2) or (3) according to the present invention, R ¹ and R ² can be easily obtained as a hydroxyl group, and the surface-modified colloidal silica in the polishing composition for CMP can be obtained. Since dispersion stability of is favorable, it is preferable.

As one of the manufacturing methods of the surface modified colloidal silica of this invention, For example, from the silane coupling agent which has an isocyanate group, and the EO compound or the hydroxy compound which has EO and PO, General formula (a11), (a12), ( General formula (1) having a group selected from a13), (a21), (a22), (a23), (a31), (a32), (a33), (a41), (a42), and (a43) , Or a method of reacting a colloidal silica with a modifier compound that gives a group represented by (2) or (3) in advance, or reacting a silane coupling agent having an isocyanate group with colloidal silica, followed by EO or EO A method of further reacting with a hydroxy compound having PO may be used. Since the control of the reaction is easy and the manufacturing cost is small, it is preferable to use the former method.

As a silane coupling agent which has the said isocyanate group, As a compound represented by following General formula (4), As a EO compound or hydroxy compound which has EO and PO, As a compound represented by General formula (5), and a modifier compound, General formula (6) And the compound represented by (7).

(Wherein Z represents a group which reacts with a silanol group to form a siloxane bond, R ⁴ to R ⁷ represent Z, an alkyl group having 1 to 4 carbon atoms, a phenyl group or a hydroxyl group, and X represents 1 to 1 carbon atoms) An alkylene group of 18 is represented, and R ³ , EO, PO, m, n, and p are the same as in the case of the group represented by the general formula (1), (2) or (3).

Moreover, as a method other than the manufacturing method of the said surface modified colloidal silica, it is a general formula (a51), (a52) from the silane coupling agent which has an amino group, and the (meth) acryl compound which has EO or EO and PO, for example. ), (a53), (a61), (a62) and (a63) having previously modified a modifier compound to impart the group represented by the general formula (1), (2) or (3), and The method of reacting colloidal silica may be sufficient, and the method of making EO or the (meth) acryl compound which has EO and PO react further after making the silane coupling agent which has an amino group, and colloidal silica react. Since the control of the reaction is easy and the manufacturing cost is small, it is preferable to use the former method.

As a silane coupling agent which has the said amino group, As a compound represented by following General formula (8), (EO) or a (meth) acryl compound which has EO and PO, As a compound represented by General formula (9), and a modifier compound, General formula ( The compound represented by 10) is mentioned.

(Wherein Z represents a group reacting with a silanol group to form a siloxane bond, R ⁴ to R ⁷ represent Z, an alkyl group having 1 to 4 carbon atoms, a phenyl group or a hydroxyl group, and X represents 1 to 1 carbon atoms) An alkylene group of 18 is represented, R represents a hydrogen atom or a methyl group, and EO, PO, m, n, and p are the same as in the case of the group represented by the general formula (1), (2) or (3). .)

As Z of the said general formula (4), (6), (7), (8), and (10), a methoxy group, an ethoxy group, a propoxy group, isopropoxy group, butoxy group, s-butoxy group, iso part Alkoxy groups, such as a oxy group, t-butoxy group, and a phenoxy group; Halogen groups such as chlorine, cancellation and oxo; Hydrogen; A hydroxyl group is mentioned.

The preferred form of R ^1, R ² of the present invention, to obtain a hydroxyl group in the surface-modified colloidal silica, with a as a starting material Z, R ^4, R ^5, R ^6, R ⁷ using the alkoxy group, and the colloidal silica The reaction may be performed. A ¹ is at least ^{one group} of (a11), (a12), (a13), (a3l), (a32), (a33), (a51), (a52) and (a53), but these may be selectively It is difficult to control, and A ² is similar to at least one of (a21), (a22), (a23), (a41), (a42), (a43), (a61), (a62) and (a63). It's a spirit.

In general, it is difficult to modify all of the reactive silanol groups on the surface of the colloidal silica with a group represented by the general formula (1), (2) or (3), and the surface-modified colloidal silica surface of the present invention Surface modifiers other than the silanol groups of the reaction and / or groups represented by the general formula (1), (2) or (3) may be present.

When obtaining colloidal silica modified by surface modifiers other than the group represented by the said General formula (1), (2), or (3), General formula (1) using colloidal silica modified with such a group previously as a raw material ), (2) or (3) may be introduced into the colloidal silica, and after introducing the group represented by the formula (1), (2) or (3), the formula (1), (2) or You may introduce groups other than the group represented by (3). As a compound which introduce | transduces groups other than group represented by General formula (1), (2) or (3), Halogenated alkylsilanes, such as chlorotrimethylsilane, chlorodimethyl octadecylsilane, dichlorodimethylsilane, and trichloromethylsilane; Alkoxyalkylsilanes such as trimethylmethoxysilane, dimethyldiethoxysilane, methyltriethoxysilane, methoxydimethyloctadecylsilane and dimethyloctadecylsilane; 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- Silane coupling agents such as (2-aminoethyl) aminopropyltriethoxysilane, 3-isocyanatepropyltriethoxysilane and 3-isocyanatepropyltrimethoxysilane; Boric acid, aluminic acid, etc. are mentioned.

Although it is difficult to directly and accurately measure the degree of surface modification in the surface modified colloidal silica of the present invention, control is possible by changing the ratio of the surface modifier (or silane coupling agent) and colloidal silica at the time of synthesis. . For example, when using the surface modified colloidal silica of this invention for the CMP polishing composition, what is necessary is just to use a modifier compound in the ratio of 1 mass part to 100 mass parts with respect to 100 mass parts of colloidal silica. In order to fully suppress dishing, 1-20 mass parts is preferable with respect to 100 mass parts of colloidal silica, and, as for the usage-amount of a modifier compound, 1-10 mass parts is more preferable.

In the surface modified colloidal silica of the present invention, the particle diameter of the colloidal silica subjected to surface modification is not particularly limited, and may be stably dispersed in water as a dispersion medium. In the case where the colloidal silica is used in the polishing composition for CMP of the present invention, the particle size is preferably in the range of 1 to 400 nm, more preferably in the range of 10 to 300 nm.

Examples of applications other than the polishing composition for CMP of the surface modified colloidal silica of the present invention include polymer material modifiers, polymer flocculants, adsorbents, paint additives, hard coat agents, anti-slip agents, antireflection agents for optical films, metal surface treatment agents, and heat resistant agents. , Inorganic fillers, inorganic binders, antistatic agents, catalyst carriers, organosols, and the like.

Next, the polishing composition for CMP of the present invention will be described.

The polishing composition for CMP of the present invention contains the above-described surface modified colloidal silica as polishing particles, and other components contained therein include an oxidant component, a heterocyclic compound component, an organic acid component, an aqueous polymer component and a pH adjuster. A component, surfactant component, a solubilizer component, etc. are mentioned. Since the polishing composition for CMP of the present invention has a property of providing good polishing against residual film, dishing, and scratch for removal of copper-based materials such as copper and copper alloy, wiring by the damascene method in the manufacture of semiconductor devices. Suitable for the forming process. In addition, the polishing composition for CMP of the present invention can be used for both the first stage polishing and the second stage polishing, and is particularly preferable for the first stage polishing because of the selective polishing property for the copper-based material.

As for content of the surface modified colloidal silica in the CMP polishing composition of this invention, 0.01-10 mass% is preferable. If the content of the surface-modified colloidal silica is less than the lower limit, the polishing rate may be slow. If the content of the surface-modified colloidal silica is more than the upper limit, it may be difficult to suppress dishing. As for content of surface modified colloidal silica, the range of 0.05-5 mass% is more preferable.

The polishing composition for CMP of the present invention may contain abrasive grain components other than the surface modified colloidal silica of the present invention. 100 mass parts or less are preferable with respect to 100 mass parts of surface modified colloidal silicas of this invention, and, as for the usage-amount in the case of including these, 50 mass parts or less are more preferable. Examples of the abrasive particles to be contained include colloidal silica, amorphous silicon dioxide, aluminum oxide, cerium oxide, silicon nitride, zirconium oxide, silicon carbide, and manganese dioxide other than the present invention. It is available.

Examples of the oxidizing agent used in the oxidizing agent components include nitric acid, peroxo acid, potassium peroxoate, lithium peroxoate, sodium peroxoate, potassium permanganate, lithium permanganate, sodium permanganate, dichromic acid, potassium dichromate, lithium dichromate and sodium dichromate. , Hydrogen peroxide, perchloric acid, perchlorate (alkali metal salt, ammonium salt, etc.), hypochlorous acid, hypochlorite (alkali metal salt, ammonium salt, etc.), persulfate, persulfate (alkali metal salt, ammonium salt, etc.), peracetic acid, t-butyl hydroperoxide , Perbenzoic acid, ozone, and the like, and these are used in one kind or a mixture of two or more kinds.

Preferable content of the oxidizing agent component in the CMP polishing composition of this invention is 0.01-10 mass%. If the content of the oxidant component is less than the lower limit, a sufficient polishing rate may not be obtained. If the content of the oxidant component is more than the upper limit, etching may not be controlled, which may cause defects such as dishing.

What is suitable as an oxidizing agent used when using the CMP polishing composition of this invention for a 1st stage grinding | polishing is a persulfate which is easy to control a polishing rate and an etching suppression, and ammonium persulfate promotes chemical polishing, and flatness of a polishing surface is carried out. Since it improves, it is more preferable. In addition, when using the polishing composition for CMP of this invention for 2nd stage grinding | polishing, it is preferable to use hydrogen peroxide which has an inhibitory effect of a polishing residue as an oxidizing agent.

Said heterocyclic compound component mainly functions as a corrosion inhibitor with anticorrosive effect with respect to a copper wiring or a barrier metal, 1,2,4-triazole, 3-amino-1H-1,2,4-triazole, 4-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 1H-tetrazole, 5- Azole monocyclic compounds such as methyl-1H-tetrazole, 5-phenyltetrazole, 1H-tetrazole-1-acetic acid, and 5-amino-1H-tetrazole; 2-mercaptobenzothiazole, 2- [2- (benzothiazolyl)] thiopropionic acid, 2- [2- (benzothiazolyl)] thiobutyl acid, benzoimidazole, benzotriazole, benzothiazole, 2 -Aminobenzothiazole, 2-amino-6-methylbenzothiazole, 1-hydroxybenzotriazole, 1-dihydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxy Propylbenzotriazole, 4-hydroxybenzotriazole, 5-hexylbenzotriazole, [1,2,3-benzotriazol-1-methyl] [1,2,4-triazolyl-1-methyl] [ 2-ethylhexyl] amine, 4-methyl-1H-benzotriazole, 5-methyl-1H-benzotriazole, naphthotriazole, bis [(1-benzotriazolyl) methyl] phosphonic acid, 1,5- Azole complex reflux such as pentamethylene tetrazole, thiavendazole, and the like, and these are used in one kind or a mixture of two or more kinds.

As for content of the heterocyclic compound in the CMP polishing composition of this invention, 0.0001-1 mass% is preferable. When the content of the heterocyclic compound is smaller than the lower limit, it is difficult to suppress dishing and corrosion, which is a use effect, and when the content of the heterocyclic compound is higher than the upper limit, the polishing rate is slow. Among these, benzotriazole is preferable because it is inexpensive and easy to control anticorrosive action.

The above organic acid component is an organic acid or a salt of an organic acid, and the use effect varies depending on the structure. For example, aliphatic organic acids, aliphatic sulfonic acids and these salts have the effect of increasing the stability of the polishing composition for CMP, and also eluting metals such as polished copper to improve the polishing rate. Aromatic sulfonic acid and aromatic sulfonic acid salt have the effect of suppressing excessive etching of metal and the like and improving the flattening of the polished surface. The amino acid and its salt also function as an anticorrosive agent.

Examples of the organic acid include formic acid, acetic acid, propionic acid, butyric acid, gilacetic acid, 2-methyl butyric acid, n-hexanoic acid, 3,3-dimethyl butyric acid, 2-ethyl butyric acid, 4-methylpentanoic acid, n-heptanoic acid, glycolic acid, Aliphatic organic carboxylic acids such as glycerin acid, oxalic acid, maronic acid, succinic acid, glutaric acid, adipic acid, pimeline acid, maleic acid, fmaric acid, lactic acid, malic acid, tartaric acid, citric acid, gluconic acid and acetic anhydride; Benzoic acid, 2-hydroxy benzoic acid, 3-hydroxy benzoic acid, 4-hydroxy benzoic acid, o-phthalic acid, m-phthalic acid, p-phthalic acid, quinalic acid, naphthalene-1-carboxylic acid, naphthalene-2-carboxylic acid Aromatic carboxylic acids; Methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, pentanesulfonic acid, hexanesulfonic acid, heptanesulfonic acid, octanesulfonic acid, norbornenesulfonic acid, adamantanesulfonic acid, cyclohexanesulfonic acid, camphorsulfonic acid, trifluoromethanesulfonic acid, pentafluoroethanesulfonic acid, Aliphatic sulfonic acids such as heptafluoropropanesulfonic acid; Aromatic sulfonic acids such as benzenesulfonic acid, p-toluenesulfonic acid, octylbenzenesulfonic acid, decylbenzenesulfonic acid, dodecylbenzenesulfonic acid, naphthalene-1-sulfonic acid, naphthalene-2-sulfonic acid, anthracenesulfonic acid, acenaphthesulfonic acid and phenanthrenesulfonic acid; Glycine, L (D) -alanine, L (D) -2-aminobutyric acid, L (D) -norvaline, L (D) -valine, L (D) -leucine, L (D) -norleucine, L (D) -Isoleucine, L (D) -alloisoycin, L (D) -phenylalanine, L (D) -proline, sarcosine, L (D) -ornithine, L (D) -lysine, taurine, L (D) -serine, L (D) -threonine, L (D) -allotheonine, L (D) -homoserine, L (D) -tyrosine, β- (3,4-dihydroxyphenyl)- L (D) -alanine, L (D) -thyroxine, 4-hydroxy-L (D) -proline, L (D) -cysteine, L (D) -methionine, L (D) -ethionine, L (D) -lanthionine, L (D) -cystionine, L (D) -cystine, L (D) -cysteinic acid, L (D) -aspartic acid, L (D) -glutamic acid, S- (carboxy Methyl) -L (D) -cysteine, 4-aminobutyric acid, L (D) -asparagine, L (D) -glutamine, L (D) -arginine, δ-hydroxy-L (D) -lysine, L ( Amino acids such as D) -histidine and L (D) -tryptophan; And alkali metal salts (lithium salts, potassium salts, sodium salts), ammonium salts and amine salts of organic acids, and these are used in one kind or a mixture of two or more kinds.

As for content of the organic acid component in the CMP polishing composition of this invention, 0.0001-10 mass% is preferable. If the content of the organic acid component is less than 0.0001% by mass, the use effect may not be obtained. If the content of the organic acid component exceeds 10% by mass, the use effect may be excessive, resulting in flatness, polishing efficiency or polishing selectivity. It may cause a fall.

As said aqueous polymer component, the water-dispersible high molecular compound used as a water-soluble polymer which acts on the improvement of polishing selectivity by barrier layer grinding | polishing suppression, and stabilization of the dispersion | distribution of abrasive grains, abrasive grains, and an abrasive grain auxiliary agent is mentioned.

The polishing composition for CMP of the present invention may contain an aqueous polymer component. Examples of the water-soluble polymer to be contained include polysaccharides such as alginic acid, pectinic acid, carboxymethyl cellulose, agar, curdlan and pullulan; Polyaspartic acid, polyglutamic acid, polylysine, polyamic acid, polymethacrylic acid, polyamic acid, polymaleic acid, polyitaconic acid, polypmamic acid, poly (p-styrenecarboxylic acid), polyacrylic acid, and polyglyoxylic acid Examples include polycarboxylic acid, polymethacrylate ammonium salt, polymethacrylate sodium salt, polyacrylamide, polyaminoacrylamide, polyammonium salt, sodium polyacrylate salt, ammonium polyamate salt, sodium polyamate salt, and the like. Salts, esters and derivatives of polycarboxylic acids; Vinyl polymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrolein, polyvinylpyrrolidone and copolymers of? Olefins (ethylene, propylene, 1-butene, 1-pentene, etc.); Polyalkylene glycols, such as polyethylene glycol, polypropylene glycol, alkylene glycol, or the random or block addition product of ethylene oxide and propylene oxide of polyalkylene glycol, are mentioned, As a water-dispersible polymer, a polyurethane resin and a polyurethane Polyurea resin, acrylic resin, methacryl resin, phenol resin, urea resin, melamine resin, polystyrene resin, polyacetal resin, polycarbonate resin. These aqueous polymers are used by one type or two or more types of mixtures.

Preferable content of an aqueous high molecular component is 0.001-10 mass%. If the content of the aqueous polymer component is less than the lower limit, sufficient use effects may not be obtained. If the content of the aqueous polymer component is more than the upper limit, a sufficient polishing rate may not be obtained. In addition, the preferable number average molecular weight (GPC measurement, standard polystyrene conversion) of a water-soluble polymer changes with kinds, and there exists an appropriate value, respectively.

One suitable as the water-soluble polymer contained in the polishing composition for CMP of the present invention is polyvinylpyrrolidone, polyvinylpyrrolidone and 1-butene copolymer. Compared with other water-soluble polymers, these have the effect of suppressing barrier layer polishing and improving the selective polishing of copper. Moreover, the effect which improves the dispersion stability of abrasive grain is also large. Preferable content of these polyvinylpyrrolidone or polyvinylpyrrolidone, and 1-butene copolymer in the CMP polishing composition of this invention is 0.001-5 mass% which an effect expresses in suppressing polishing of a barrier layer. Moreover, as a number average molecular weight, 5000-100000 are preferable.

Moreover, one of the thing suitable as water-soluble polymer contained in the CMP polishing composition of this invention is polyalkylene glycol. Polyalkylene glycol exhibits an excellent polishing rate compared with other water-soluble polymers, and also has a great effect of improving the dispersion stability of the abrasive grains. Preferable content of the polyalkylene glycol in the polishing composition for CMP of this invention is 0.001-5 mass% in which an effect expresses in suppressing polishing of a barrier layer. Moreover, as a number average molecular weight of polyalkylene glycol, 200-3000 are preferable.

Moreover, one of the thing suitable as a water dispersible polymer contained in the CMP polishing composition of this invention is a polyurethane resin and a polyurethane polyurea resin. These are effective because they enhance selective abrasiveness or non-selective abrasiveness with respect to selective abrasiveness as preparation of abrasive particles and abrasive particles. In the polyurethane resin or the polyurethane polyurea resin, since the emulsifier which disperses this may affect CMP performance, self-emulsification which is easy to control CMP performance is preferable.

The cationic water-dispersed polyurethane incorporating a cationic group has a strong etching effect on copper and may be difficult to control. Thus, a nonionic water-dispersible polyurethane or anionic Water dispersion type polyurethane is more preferable, and anionic water dispersion type polyurethane is more preferable because copper's polishing rate is large. In addition, in the case of an anionic water-dispersed polyurethane, 1-200 are preferable and, as for an acid value (mgKOH / g), 10-150 are more preferable.

The average particle diameter of the water-dispersed polyurethane is preferably 5 to 200 nm, more preferably 10 to 150 nm, which functions as polishing particles and can be stably dispersed in the polishing composition for CMP. Preferable content of these resin in the CMP polishing composition of this invention is 0.01-10 mass%.

The polishing composition for CMP of the present invention may be used in an acidic or basic manner so that the oxidant functions, and a pH adjuster may be used therefor.

As a pH adjuster component used for the CMP polishing composition of this invention, a water-soluble basic compound and a water-soluble acidic compound are mentioned. Examples of the water-soluble basic compound include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkali earth metal hydroxides such as calcium hydroxide, strontium hydroxide and barium hydroxide, and alkali metal carbonates such as ammonium carbonate, lithium carbonate, sodium carbonate and potassium carbonate. And quaternary ammonium hydroxides such as tetramethylammonium hydroxide and corinine, organic amines such as ethylamine, diethylamine, triethylamine and hydroxyethylamine, and ammonia, and these may be one or two kinds. It is used as a mixture above. Among them, ammonia and alkali hydroxide metals are preferable because they are inexpensive and easy to handle.

As a water-soluble acidic compound, inorganic acids, such as a water-soluble thing, hydrochloric acid, a sulfuric acid, and nitric acid, are mentioned among what was illustrated by organic acid.

PH of the polishing composition for CMP of this invention is 8-12 in a preferable range. If pH is less than 8 and 6 or more, sufficient grinding | polishing rate may not be obtained. Moreover, when pH is less than 6, polishing of a barrier layer may arise and the selective polishing property may fall. Moreover, when pH is larger than 12, dishing may arise and surface condition may deteriorate.

The polishing composition for CMP of the present invention may contain a surfactant in order to impart polishing inhibition, dissolution or dispersion stability of each component, antifoaming properties, and the like. As surfactant contained, nonionic surfactant, anionic surfactant, cationic surfactant, and betaine surfactant are mentioned, These are used by one type or two or more types of mixtures.

Preferable content when using the surfactant component in the polishing composition for CMP of this invention is 0.0001-10 mass%. When content of surfactant component is less than a lower limit, sufficient use effect may not be acquired, and when content of surfactant component is more than an upper limit, a grinding | polishing speed may fall.

Suitable as surfactant contained in the CMP polishing composition of this invention are anionic surfactant. Examples of the anionic surfactants include higher fatty acid salts, higher alcohol sulfate ester salts, sulfide olefin salts, higher alkyl sulfonates, α-olefin sulfonates, sulfated fatty acid salts, sulfonated fatty acid salts, phosphate ester salts, and fatty acids. Sulfate ester salts of esters, glyceride sulfate ester salts, sulfonic acid salts of fatty acid esters, α-sulfofatty acid methyl ester salts, polyoxyalkylene alkyl ether sulfate ester salts, polyoxyalkylene alkylphenyl ether sulfate ester salts, polyoxyalkyls Sulfate ester salts, benzene sulfonates, alkylbenzene sulfonates, alkylnaphthalene sulfonates, alkylbenzoimidazole sulfonates, polyoxyalkyls of ethylene alkyl ether carboxylates, acylated peptides, fatty acid alkanolamides or alkylene oxide adducts thereof Lensulfovacate, salts of N-acyl-N-methyltaurine, N-acylglutamic acid or salts thereof, acyloxyethanesulfonic acid salts, eggs Sitansulfonate, N-acyl-β-alanine or salt thereof, N-acyl-N-carboxyethyltaurine or salt thereof, N-acyl-N-carboxymethylglycine or salt thereof, acyl lactate, N-acyl sarcosine salt And 1 type, or 2 or more types of mixtures, such as an alkyl or alkenylamino carboxymethyl sulfate.

The polishing composition for CMP of the present invention may contain a metal eluent component that elutes the polished metal. For example, in the case of CMP of copper, as a metal (copper) eluent to contain, the ammonium salt and alkali metal salt of the organic acid illustrated by said organic acid component are mentioned, These are used by 1 type, or 2 or more types of mixtures.

Preferable content when using the said copper eluent is 0.01-10 mass%. If the content of the copper eluent is less than the lower limit, a sufficient polishing rate may not be obtained. If the content of the copper eluent is more than the upper limit, excessive etching may not be controlled.

Suitable as the above-mentioned copper eluents are ammonium salts of aliphatic organic carboxylic acids, in particular oxalic acid, maronic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fmaric acid, oxalic acid, malic acid, tartaric acid, Ammonium salts of citric acid are preferred. When using these, 0.05-2 mass% is preferable, and, as for the compounding quantity in the polishing composition for CMP, 0.1-1 mass% is more preferable.

The polishing composition for CMP of the present invention may contain a solubilizer component in order to stably dissolve the organic components described above. As a solubilizer to contain, Alcohol, such as methanol and ethanol; Ketones such as acetone and methyl ethyl ketone; Ethers such as diethyl ether, tetrahydrofran and dioxane; Alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether and ethylene glycol monobutyl ether; Polyalcohols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, glycerin, pentaerythritol, dipentaerythritol and tetramethylolpropane; Pyrrolidones, such as N-methylpyrrolidone, are mentioned, These are used by 1 type or mixture of 2 or more types.

When using a solubilizer, preferable content in the CMP polishing composition is 0.01-10 mass%. If the content of the solubilizer is less than the lower limit, sufficient use effects may not be obtained. If the content of the solubilizer is more than the upper limit, surface roughness of the polished surface may occur.

The polishing composition for CMP of the present invention may contain other additive components as necessary in addition to those exemplified above. As an additive component, pH buffering agent; Clathrate compounds, such as (alpha)-, (beta)-, or (gamma)-cyclodextrin which encloses the organic compound which has the effect of reducing the organic contamination of a wafer; Hydroxyalkanesulfonic acid fatty acid esters such as isethionic acid fatty acid ester for imparting surface smoothness of the polished surface; Monoethanolamine, diethanolamine, triethanolamine, 2-dimethylaminoethanol, 2- (2-aminoethylamino) ethanol for improving the dispersion stability and polishing ability of the abrasive particles by imparting a cleaning action on the surface of the abrasive particles. And alkanolamines such as N-methyl diethanolamine. When using these other additive components, it is mix | blended in the range which becomes 0.0001-10 mass%, Preferably it is 0.0005-5 mass% in the polishing composition for CMP, respectively.

The polishing composition for CMP of the present invention comprises each of the above components in the same content as described above, but the remainder is water. Therefore, water is added so that the whole may be 100 mass% so that it may become the polishing composition for CMP containing each component mentioned above by the quantity prescribed | regulated.

What is necessary is just to mix and disperse | distribute the above-mentioned components and water, and to prepare the preparation of the CMP polishing composition of this invention uniformly. When using a water-soluble polymer or a water-dispersible polymer, what is necessary is just to add them in the state of the composition which melt | dissolved or disperse | distributed previously in water. In addition, the polishing composition for CMP of the present invention may be mixed with all components to form a one-liquid type composition or a two-liquid type composition. As a two-liquid type composition, it is set as a separate component only for an oxidizing agent component, for example, and the two-liquid type with the mixture of all the other components is mentioned. When a peroxide is used for an oxidizing agent, it becomes a 2-component type composition normally.

Example

Below, an Example and a comparative example are given and this invention is demonstrated in detail. However, the present invention is not limited by the following examples and the like. On the other hand, "part" or "%" in the sentence is based on mass unless otherwise specified.

Preparation Example 1 Preparation of Surface Modifier Compounds a to q

By using 3-isocyanatepropyltrimethoxysilane as the silane coupling agent having an isocyanate group and using a diol compound or an alcohol compound as the EO or a hydroxy compound having EO and PO, the molar ratio of the hydroxyl group and the isocyanate group is OH: NCO = It mix | blended in the ratio of 1.1: 1, and stirred at 100 degreeC for 2 hours, Then, tetraisopropoxytitanium was added 0.005% of the total mass of a raw material, and it stirred further at 100 degreeC for 2 hours, and various surface modifier compounds were obtained. Termination of the reaction was confirmed by disappearance of the isocyanate group using IR. The obtained surface modifier compounds are shown in Tables 1 and 2. In addition, although m, p, n of the said General formula (6) and General formula (7) are shown in a table | surface, this is the value computed from the molecular weight of the diol compound and alcohol compound which are raw materials.

Preparation Example 2 Preparation of Surface Modifier Compounds r and s

3-aminopropyltrimethoxysilane was used as the silane coupling agent having an amino group, and NK ester A-600 having an acrylic group at the terminal of the polyethylene glycol chain was used as the hydroxy compound having EO. The molar ratio of an acryl group and an amino group was mix | blended in the ratio of 1.2: 1, and it stirred at 60 degreeC for 5 hours, and obtained the surface modifier compound r. The completion | finish of reaction was confirmed by the disappearance of 3-aminopropyl trimethoxysilane of a raw material using gas chromatography. The obtained surface modifier compound r is the said General formula (10) type, m + p = 13 (calculated value) and n = O (calculated value).

In addition, 3- [methoxypoly (ethyleneoxy)] propyltrimethoxysilane was used as the surface modifier compound s. m + p = 6-9 (calculated value) and n = O (calculated value).

Examples 1 to 5 Preparation of Surface Modified Colloidal Silica Nos. 1 to 5

Average particle diameter obtained by the hydrolysis method of tetraethoxysilane; 120.6 nm, particle size distribution: 10% cumulative value; 95.3 nm, cumulative 50% value; 117.4 nm, cumulative 90% value; dispersion of colloidal silica of 145.5 nm (Hereinafter referred to as colloidal silica A before surface modification, 10% of silicon dioxide content) was heated to 60 ° C., each of 10 parts, 50 parts of water, and 0.1 mol / liter of the surface modifier compounds a to e obtained in the above Production Example. The mixed solution of 1 part of nitric acid aqueous solution was dripped. The amount of dripping is 3 parts of surface modifier compounds with respect to 100 parts of silicon dioxide of colloidal silica. After dripping, it stirred at 60 degreeC for 2 hours, and surface modified colloidal silica Nos. 1-5 were obtained. About each obtained surface modified colloidal silica, X-ray photoelectron spectroscopy (XPS) analysis was performed and it confirmed about the surface modification compared with the colloidal silica A before surface modification. In addition, the particle size distribution by the laser diffraction particle size analyzer was measured.

Examples 6 to 13 Preparation of surface-modified colloidal silica Nos. 6 to 13

Average particle diameter obtained by hydrolysis of tetraethoxysilane; 155.9 nm, particle size distribution: 10% cumulative value; 114.3 nm, cumulative 50% value; 153.7 nm, 90% cumulative value; dispersion of colloidal silica of 208.6 nm (Hereinafter referred to as colloidal silica B before surface modification, 10% of silicon dioxide content) was heated to 60 ° C., each of 10 parts of the surface modifier compounds b, i, j to p obtained in the above Production Example, 50 parts of water, A mixed solution of 1 part of 0.1 mol / liter nitric acid aqueous solution was added dropwise. The amount of dripping is 10 parts of surface modifier compounds with respect to 100 parts of silicon dioxide of colloidal silica. After dripping, it stirred at 60 degreeC for 2 hours, and surface modified colloidal silica Nos. 6-13 were obtained. About each obtained surface modified colloidal silica, particle size distribution by the X-ray photoelectron spectroscopy (XPS) analysis and the laser diffraction type particle diameter analyzer was measured like the said Example.

(XPS analysis results)

As for surface-modified colloidal silica, Examples 1 to 13 all gave the following results.

(1) carbon atoms

The peak derived from CO was confirmed at 282.8 eV. This peak was not observed in colloidal silica before surface modification.

(2) oxygen atom

A peak of 530.6 eV was confirmed. The colloidal silica before surface modification was 531.0 eV, and the chemical shift by bond was confirmed.

(3) nitrogen atoms

A peak of 398.0 eV was confirmed. This peak was not found in colloidal silica before surface modification.

(4) silicon atoms

A peak of 101.0 eV was confirmed. The colloidal silica before surface modification was 101.7 eV, and the chemical shift by bond was observed.

Example 14 Preparation of Surface Modified Colloidal Silica No. 14

A surface modified colloidal silica was prepared in the same manner as in Examples 1 to 5, except that the surface modifier compound c was used as the surface modifier compound, and the amount of the surface modifier compound used in 100 parts of silicon dioxide of the colloidal silica was 1 part. No. 14 was obtained.

Example 15 Preparation of Surface Modified Colloidal Silica No.15

The surface-modified colloidal silica was prepared in the same manner as in Examples 1 to 5, except that the surface-modifier compound c was used as the surface-modifier compound, and the amount of the surface-modifier compound was changed to 10 parts with respect to 100 parts of silicon dioxide of the colloidal silica. No. 15 was obtained.

Comparative Example 1 Preparation of Surface Modified Colloidal Silica Comparison 1

Methyltriethoxysilane was used as the surface modifier compound, and a mixed solution consisting of 10 parts of the surface modifier compound, 50 parts of water, and 2 parts of 0.1 mol / liter nitric acid solution was added to a dispersion of colloidal silica B heated to 60 ° C. It dripped. The use amount of methyl triethoxysilane is 4 parts with respect to 100 parts of silicon dioxide of colloidal silica. A surface modified colloidal silica comparison 1 was obtained in the same manner as in Examples 6 to 13 except for the above.

Comparative Example 2 Preparation of Surface Modified Colloidal Silica Comparison 2

A surface-modified colloidal silica comparison 2 was obtained in the same manner as in Comparative Example 1 except that the amount of methyl triethoxysilane used was 10 parts with respect to 100 parts of silicon dioxide of colloidal silica.

Examples 16 to 24 Preparation of Polishing Composition Nos. 1 to 9 for CMP

Polishing composition for CMP consisting of 1% surface modified colloidal silica, 1.5% ammonium persulfate, 1% glycine, 0.001% benzotriazole, 0.02% dodecylbenzenesulfonic acid, 0.3% potassium hydroxide and water (residue) Nos. 1 to 9 were obtained.

Comparative Example 4 Preparation of 1 for Comparing Polishing Composition for CMP

Comparison of polishing composition for CMP consisting of colloidal silica B1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, potassium hydroxide 0.3% and water (residue) before surface modification Got.

Comparative Example 5 Preparation of 2 for Comparing Polishing Composition for CMP

Colloidal silica B1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, potassium hydroxide 0.3%, polyethylene glycol monomethyl ether (MePEG400) with number average molecular weight 400 before surface modification A polishing composition comparison 2 for CMP, consisting of 0.1% and water (residue), was obtained.

Comparative Example 6 Preparation of 3 for Comparing Polishing Composition for CMP

Surface modified colloidal silica comparison 1 for comparing the polishing composition for CMP consisting of 1%, ammonium persulfate 1.5%, glycine%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, potassium hydroxide 0.3% and water (residue) Got 3.

Comparative Example 7 Preparation of 4 for Comparing Polishing Composition for CMP

Compare surface modified colloidal silica comparison 2 with CMP polishing composition consisting of 1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, potassium hydroxide 0.3% and water (residue) Obtained 4

[Evaluation Example 1]

The copper blanket which cut | disconnected the wafer which formed 1500 nm film-forming the copper film on the silicon substrate by the electroplating method about CMP polishing composition No.1-No.7 of Table 5, comparative 1, and comparative 2 The polishing rate under the following polishing conditions was evaluated using the test piece and the tantalum blanket test piece which cut | disconnected the tantalum 200nm film-formed film on the silicon substrate by the sputtering method to 3cm * 3cm square as a to-be-polished body. The results are shown in Table 6. In addition, the grinding | polishing amount was measured from the film thickness difference before and behind grinding | polishing using Loresta GP (Mitsubishi Chemical Corporation).

Polishing Machine: NF-300 (Nano Factor Co., Ltd.)

Polishing pad: IC1400 (XY groove formation) (product made by Rohm and Haas)

Polishing time: 1 minute

Surface rotation speed: 60rpm

Carrier rotation speed: 60rpm

Polishing processing pressure: 2psi

Polishing liquid supply speed: 35 ml / min

From Table 6, the polishing compositions No. 1 to No. 7 for CMP using the surface-modified colloidal silica of the present invention as abrasive grains all exhibited a favorable polishing rate for copper, and confirmed polishing inhibition for tantalum. . On the other hand, the surface of the surface modified colloidal silica No. 10 used for the polishing composition comparison 1 for CMP using unmodified colloidal silica and the polishing composition No. 4 for CMP using the surface unmodified colloidal silica Comparative 2, with the addition of a significant amount of reformer MePEG400, has insufficient polishing inhibition against tantalum. From this, it can confirm that the improvement of the selective abrasiveness with respect to copper is an effect by the surface modification of the colloidal silica which is abrasive grain.

Examples 25 to 27 Preparation of Polishing Composition Nos. 10 to 12 for CMP

1-butene of surface modified colloidal silica 1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, polyvinylpyrrolidone and a number average molecular weight of 17000 Polishing compositions No. 10 to No. 12 for CMP obtained from a copolymer (P-904LC; manufactured by ISP) 0.03%, potassium hydroxide 0.3%, and water (residue).

Comparative Example 8 Preparation of 5 for Comparing Polishing Composition for CMP

Polishing composition comparison 5 for CMP was obtained by the same formulation as Examples 25 to 27, except that 1 part of colloidal silica A before surface modification was used instead of 1% of surface modified colloidal silica.

[Evaluation Example 2]

The polishing composition for CMP described in Table 7 above was evaluated by polishing rate using a copper blanket 8 inch wafer polished body formed by depositing a 1500 nm copper film on a silicon substrate by an electrolytic plating method, and by plasma CVD method using tetrakisethoxysilane. A 250 nm deep hard silica layer was formed on the hard silica layer of the wafer on which 250 nm of the hard silica film was deposited, and a groove having a depth of 50 nm and a width of 50 μm was formed with a space of 50 μm. After further depositing a seed layer, pattern formation in which a copper film 1000 nm was formed by an electrolytic plating method The dishing evaluation and the copper polishing residue evaluation which used the 8 inch wafer as a to-be-polished body were performed.

Polishing conditions are as follows. The polishing rate was measured from the film thickness difference before and after polishing using Loresta GP (Mitsubishi Chemical). The dishing was measured using the atomic force microscope (AFM) Nanopics (manufactured by Seiko Instruments Co., Ltd.). Copper polishing The residue confirmed the presence or absence of the residual film of copper at the time of 20% overpolishing (over polish) with the optical microscope. The results are shown in Table 8.

Polishing machine: AVANTI472 (IPEC company product)

Polishing pad: IC1400 (XY groove formation) (product made by Rohm and Haas)

Polishing time: 1 minute

Surface rotation speed: 93rpm

Carrier speed: 87rpm

Polishing processing pressure: 2psi

Polishing liquid supply speed: 200 ml / min

From Table 8, it can be confirmed that the polishing compositions No. 10 to No. 12 for CMP using the surface-modified colloidal silica of the present invention as polishing particles have an inhibitory effect on copper polishing residues. The suppressing effect of copper polishing residue is so large that the degree of surface modification of the colloidal silica used is large. On the contrary, the dishing also confirmed that the greater the degree of surface modification of colloidal silica, the smaller the inhibitory effect. It can be seen that it is possible to provide a polishing composition for CMP with no copper polishing residues while suppressing dishing depending on the amount of surface modification of the surface modified colloidal silica.

Examples 28 to 30 Preparation of Polishing Composition Nos. 13 to 15 for CMP

Surface modified colloidal silica 1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, polyvinylpyrrolidone and 1-butene having a number average molecular weight of 17000 Polishing compositions No. 13 to No. 15 for CMP comprising a copolymer (P-904LC; manufactured by ISP) 0.03%, potassium hydroxide 0.3% and water (residue) were obtained.

[Evaluation Example 3]

For the polishing composition for CMP described in Table 9 above, a copper blanket 8 inch wafer formed by depositing a 1500 nm copper film on a silicon substrate by an electroplating method, and a tantalum blanket 8 inch wafer formed by depositing tantalum 200 nm on a silicon substrate by a sputtering method were polished. After the evaluation of the polishing rate with a sieve and the plasma CVD method using tetrakisethoxysilane and the 500 nm of hard silica film formed on the hard silica layer of the wafer, a 500 nm deep groove having a width of 50 μm was formed with a space of 50 μm, followed by sputtering. The tantalum film was deposited by 25 nm, the 100 nm copper seed layer was further deposited by sputtering, and then a dishing evaluation and a copper polishing residue evaluation using an 8-inch wafer on which a 1000 nm copper film was formed by electrolytic plating were performed as an abrasive. .

Polishing conditions are as follows. The polishing rate was measured from the film thickness difference before and after polishing using Loresta GP (Mitsubishi Chemical). The dishing was measured using the atomic force microscope (AFM) Nanopics (manufactured by Seiko Instruments Co., Ltd.). The presence of the copper polishing residue and the residual film of copper at the time of 20% overpolishing (overpolicy) with respect to copper was confirmed with the optical microscope. The results are shown in Table 10.

Polishing machine: AVANTI472 (IPEC company product)

Polishing pad: ICI400 (XY groove formation) (product made by Rohm and Haas)

Polishing time: 1 minute

Surface rotation speed: 93rpm

Carrier speed: 87rpm

Polishing processing pressure: 2psi

Polishing liquid supply speed: 200 ml / min

From Table 10, it was confirmed that the polishing compositions Nos. 13 to 15 for CMP using the surface-modified colloidal silica of the present invention as abrasive grains had an inhibitory effect on copper polishing residues. It was also confirmed that the suppressing effect of the copper polishing residue was better as the molecular weight of polyethylene glycol used as a raw material for the surface modifier of colloidal silica to be used was smaller. It can be seen that it is possible to provide a polishing composition for CMP having no copper polishing residue while suppressing dishing by the molecular weight of the polyether chain of the surface modifying agent of the surface modified colloidal silica.

[Evaluation Example 4]

Polishing evaluation similar to the said evaluation example 3 was performed about the CMP polishing composition comparison 3 and 4 obtained by the comparative examples 6 and 7. The results are shown in Table 11.

From Table 11, the CMP polishing composition comparison 3 and 4 for the use of colloidal silica surface-modified with methyltriethoxysilane has no inhibitory effect on the copper polishing residues, and the degree of surface modification of the colloidal silica No correlation was found for the inhibitory effect of dishing. In addition, it could be confirmed that as the degree of surface modification of colloidal silica increases, the polishing rate of copper decreases. It can be seen that the use effect is different from the surface modified colloidal silica of the present invention.

Examples 31 to 38 Preparation of Surface Modified Colloidal Silica Nos. 16 to 23

Average particle diameter obtained by hydrolysis of tetraethoxysilane; 120.6 nm, particle size distribution: cumulative 10% value; 84.7 nm, cumulative 50% value; 112.7 nm, cumulative 90% value; 150.0 nm colloidal silica dispersion (hereinafter referred to as colloidal silica C before surface modification, silicon dioxide 10% of content) was heated at 60 degreeC, and the mixed solution of 10 parts, 50 parts of water, and 1 part of 0.1 mol / liter nitric acid aqueous solution of the surface modifier compounds a-h obtained by the said manufacture example was dripped. The amount of dripping is 3 parts of surface modifier compounds with respect to 100 parts of silicon dioxide of colloidal silica. It stirred at 60 degreeC after dripping for 2 hours, and obtained surface modified colloidal silica Nos. 16-23. About each obtained surface modified colloidal silica, X-ray photoelectron spectroscopy (XPS) analysis was performed like Example 1-13, and it confirmed about surface modification compared with colloidal silica C before surface modification.

Examples 39 to 46 Preparation of Polishing Composition Nos. 16 to 23 for CMP

Polishing compositions No. 16 to No. 23 for CMP, which consist of 1% of surface modified colloidal silica shown in Table 12, 1.5% of ammonium persulfate, 0.3% of ammonium sulfate, 0.4% of potassium hydroxide and water (residue).

Comparative Example 9 Preparation of 6 for Comparing Polishing Composition for CMP

A polishing composition comparison 6 for CMP consisting of 1% colloidal silica C, 1.5% ammonium persulfate, 0.3% ammonium sulfate, 0.4% potassium hydroxide and water (residue) was obtained before surface modification.

[Evaluation Example 5]

The copper blanket test piece which cut | disconnected the wafer which formed 1500 nm of copper films on the silicon substrate by the electroplating method about CMP polishing composition Nos. 16-23, and Comparative 6 of Table 12 to 3 cm * 3 cm square, The polishing rate by the following polishing conditions was evaluated using the tantalum blanket test piece which cut | disconnected the wafer which formed 150 nm of tantalum on the silicon substrate by the sputtering method to 3cm * 3cm square as a to-be-polished body. The results are shown in Table 13. In addition, the grinding | polishing amount was measured from the film thickness difference before and behind grinding | polishing using Loresta GP (Mitsubishi Chemical Corporation).

Polishing Machine: NF-300 (Nano Factor Co., Ltd.)

Polishing pad: IC1000 (XY groove formation) (product made by Rohm and Haas)

Polishing time: 2 minutes

Surface rotation speed: 60rpm

Carrier rotation speed: 60rpm

Polishing processing pressure: 3psi

Polishing liquid supply speed: 30 ml / min

From Table 13, it can be seen that as the molecular weight of polyethylene glycol used as a raw material of the surface modifier of colloidal silica used increases, the copper polishing rate decreases only slightly, while the tantalum polishing rate decreases significantly. That is, it was confirmed that the greater the molecular weight of the surface modifier compound, the better the copper / tantalum polishing selectivity.

Example 47, 48 Preparation of surface-modified colloidal silica No. 24, No. 25

Surface modifier compounds q and s were used as surface modifier compounds, respectively, and surface modified colloidal silica Nos. 24 and No. 25 were obtained in the same manner as in Examples 31 to 38.

Example 49 Preparation of Surface Modified Colloidal Silica No. 26

The surface modifier compound r was used as a surface modifier compound, and the mixed solution which consists of 10 parts of surface modifier compounds r and 50 parts of water was dripped at the dispersion of colloidal silica C heated at 60 degreeC. The amount of dripping is 3 parts of surface modifier compounds with respect to 100 parts of silicon dioxide of colloidal silica. After dripping, it stirred at 60 degreeC for 2 hours, and surface modified colloidal silica No. 26 was obtained.

Examples 50 to 52 Preparation of Polishing Compositions No. 24 to No. 26 for CMP

No. 24 to 26 surface modified colloidal silica 1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, polyvinylpyrrolidone and a number average molecular weight of 17000 Polishing compositions No. 24 to No. 26 for CMP comprising a copolymer of butene (P-904LC; manufactured by ISP) 0.03%, potassium hydroxide 0.3% and water (residue).

Comparative Example 10 Preparation of 7 for Comparing Polishing Composition for CMP

Copolymer of colloidal silica C1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, polyvinylpyrrolidone and 1-butene with a number average molecular weight of 17000 before surface modification ( P-904LC; manufactured by ISP Co., Ltd.) A polishing composition for CMP comparison 7 consisting of 0.03%, potassium hydroxide 0.3% and water (residue) was obtained.

[Evaluation Example 6]

For the CMP polishing compositions of Examples 50 to 52 and Comparative Example 10, a copper blanket 8-inch wafer in which a copper film was formed on a silicon substrate by 1500 nm by an electrolytic plating method, and a tantalum blanket in which 150 nm of tantalum was formed on a silicon substrate by a sputtering method. Evaluation of the polishing rate using an 8-inch wafer as an abrasive and a 500 nm deep groove having a depth of 50 nm and a width of 50 μm in the hard silica layer of the wafer on which 500 nm of the hard silica film was formed by plasma CVD using tetrakiethoxysilane. After the deposition, the tantalum film was deposited by 25 nm by sputtering, a 100 nm copper seed layer was further deposited by sputtering, and then the dishing evaluation and copper polishing using an 8-inch wafer on which a 1000 nm copper film was formed by electroplating was performed. Residue evaluation was performed.

Polishing conditions are as follows. The polishing rate was measured from the film thickness difference before and after polishing using Loresta GP (Mitsubishi Chemical). The dishing was measured using the atomic force microscope (AFM) Nanopics (manufactured by Seiko Instruments Co., Ltd.). The copper grinding | polishing residue confirmed the presence or absence of the residual film of copper at the time of 40% overpolishing (overpolicy) with respect to copper with the optical microscope. The results are shown in Table 14.

Polishing machine: AVANTI472 (IPEC company product)

Polishing pad: IC1400 (XY groove formation) (product made by Rohm and Haas)

Polishing time: 1 minute

Surface rotation speed: 93rpm

Carrier speed: 87rpm

Polishing processing pressure: 2psi

Polishing liquid supply speed: 200 ml / min

From Table 14, it was confirmed that the polishing compositions No. 24 to No. 26 for CMP using the surface-modified colloidal silica of the present invention as polishing particles had an inhibitory effect on the copper polishing residues. From this, it can be seen that the polyethylene glycol structure of the surface modifier compound contributes to the inhibitory effect of the copper polishing residue. In addition, the polishing compositions No. 24 to No. 26 for CMP could all be polished without losing their flatness significantly.

Comparative Example 11 Preparation of Surface Modified Colloidal Silica Comparison 3

A colloidal silica C obtained by using a glycidpropyl triethoxysilane as the surface modifier compound and heating a mixed solution of 10 parts of the surface modifier compound, 50 parts of water and 5 parts of an aqueous 0.1 mol / liter nitric acid solution at 60 ° C. It was dripped at the dispersion liquid. The usage-amount of glycidpropyl triethoxysilane is 3 parts with respect to 100 parts of silicon dioxide of colloidal silica. After dripping, it stirred at 60 degreeC for 2 hours, and surface modified colloidal silica comparison 3 was obtained.

Comparative Example 12 Preparation of Surface Modified Colloidal Silica Comparison 4

Colloidal silica obtained by using 3-ureapropyltriethoxysilane as a surface modifier compound, and heating a mixed solution consisting of 10 parts of surface modifier compound, 50 parts of water and 1 part of 0.1 mol / liter nitric acid aqueous solution to 60 ° C. It was dripped at the dispersion of C. The usage-amount of 3-ureapropyl triethoxysilane is 3 parts with respect to 100 parts of silicon dioxide of colloidal silica. After dripping, it stirred at 60 degreeC for 2 hours, and surface modified colloidal silica comparison 4 was obtained.

Comparative Example 13 Preparation of Surface Modified Colloidal Silica Comparison 5

A colo obtained by heating a mixed solution composed of (3-mercaptopropyl) triethoxysilane as a surface modifier compound, 10 parts of surface modifier compound, 50 parts of water, and 2 parts of 0.1 mol / liter nitric acid aqueous solution to 60 ° C. It was dripped at the dispersion of the silica C this month. The usage-amount of (3-mercaptopropyl) triethoxysilane is 3 parts with respect to 100 parts of silicon dioxide of colloidal silica. After dripping, it stirred at 60 degreeC for 2 hours, and surface modified colloidal silica comparison 5 was obtained.

[Comparative Examples 14 to 16] Preparation of 8 to 10 for Comparing Polishing Composition for CMP

Surface modified colloidal silica 1%, ammonium persulfate 1.5%, glycine 1%, benzotriazole 0.001%, dodecylbenzenesulfonic acid 0.02%, polyvinylpyrrolidone and the number average molecular weight 17000 of the comparative examples 11 to 13 8-10 for the CMP polishing composition comparison which consisted of 0.03% of butene copolymers (P-904LC; the product made by ISP), 0.3% of potassium hydroxide, and water (residue) were obtained.

[Evaluation Example 7]

For the CMP polishing composition of Comparative Examples 14 to 16, a copper blanket 8 inch wafer in which a copper film was formed on a silicon substrate by 1500 nm by an electrolytic plating method, and a tantalum blanket 8 inch wafer in which 150 nm of tantalum was formed on a silicon substrate by a sputtering method were used. After evaluating the polishing rate of the abrasive and the plasma CVD method using tetrakiethoxysilane, 500 nm deep grooves having a width of 50 μm and a width of 50 μm were formed in the hard silica layer of the wafer on which 500 nm of the hard silica film was formed, with a space of 50 μm, After sputtering, a tantalum film was deposited by 25 nm, a 100 nm copper seed layer was further deposited by sputtering, and then dishing evaluation and copper polishing residue evaluation using an 8-inch wafer formed with a 1000 nm copper film by an electroplating method as an abrasive. It was done.

Polishing conditions are as follows. The polishing rate was measured from the film thickness difference before and after polishing using Loresta GP (Mitsubishi Chemical). The dishing was measured using the atomic force microscope (AFM) Nanopics (manufactured by Seiko Instruments Co., Ltd.). The copper grinding | polishing residue confirmed the presence or absence of the film | membrane of the copper at the time of 40% excess grinding | polishing (over polished) with respect to copper with the optical microscope. The results are shown in Table 15.

Polishing machine: AVANTI472 (manufactured by IPEC)

Polishing pad: IC1400 (XY groove formation) (product made by Rohm and Haas)

Polishing time: 1 minute

Surface rotation speed: 93rpm

Carrier speed: 87rpm

Polishing processing pressure: 2psi

Polishing liquid supply speed: 200 ml / min

From Table 15, the polishing composition comparison 8 for CMP using colloidal silica surface-modified with glycidpropyltriethoxysilane had no dishing inhibitory effect, and the flatness after polishing by the polishing composition comparison 8 for CMP was also poor. It can be seen that. In addition, although the polishing composition comparison 9 for CMP using the colloidal silica surface-modified with 3-ureidepropyltriethoxysilane showed the polishing inhibition with respect to tantalum, it did not show the inhibitory effect with respect to copper polishing residue. The polishing composition comparison 10 for CMP using colloidal silica surface-modified with (3-mercaptopropyl) triethoxysilane showed polishing inhibition on tantalum but did not show a sufficient polishing rate on copper.

Example 53 Preparation of Surface Modified Colloidal Silica No. 27

Surface-modified colloidal silica No. 27 was carried out in the same manner as in Examples 1 to 5, except that surface modifier compound b was used as the surface modifier compound, and the amount of the surface modifier compound used for 100 parts of silicon dioxide of the colloidal silica was 7 parts. Got.

Examples 54 to 58 Preparation of Polishing Compositions No. 28 to No. 32 for CMP

Surface Modified Colloidal Silica 6.5%, No. 25-No. 27, No. 1 Hydrogen Peroxide, 0.02% Benzotriazole, 0.02% Dodecylbenzenesulfonic Acid, 0.1% Potassium Hydrogen Carbonate, 1.2% Potassium Hydroxide, Polyethylene Glycol (PEG400) Polishing compositions No. 28 to No. 32 for CMP comprising 0.1% and water (residue) were obtained.

Comparative Example 17 Preparation of 11 for Comparison of Polishing Composition for CMP

Before surface modification, colloidal silica A 6.5%, hydrogen peroxide 1%, benzotriazole 0.02%, dodecylbenzenesulfonic acid 0.02%, potassium hydrogencarbonate 0.1%, potassium hydroxide 1.2%, polyethylene glycol (PEG400) 0.1% and water (residue) A CMP polishing composition comparison 11 was obtained.

[Evaluation Example 8]

For the CMP polishing compositions of Examples 54 to 58 and Comparative Example 17, a copper blanket in which a copper film was formed on a silicon substrate by 1500 nm in a copper blanket, and a tantalum blanket 8 in which 150 nm of tantalum was formed on a silicon substrate by an 8-inch wafer sputtering method. Inch wafer, PE-TEOS blanket 8-inch wafer with PE-TEOS 800nm deposited on silicon base by plasma CVD method, BD1 blanket 8-inch wafer with 1000 nm of Black Diamo nd1 (BDI) deposited on silicon base by plasma CVD Evaluation of the polishing rate of the polished body and the chipping phenomenon of the 854 patterned wafer including the 450 nm BD1 insulating film on which the plated copper film was removed under the same conditions were evaluated.

Polishing conditions are as follows. The polishing rate of the copper film and the tantalum film was measured using Loresta GP (Mitsubishi Chemical), and the polishing rate of the PE-TEOS film and the BD1 film was measured from the film thickness difference before and after polishing using F20-2 (manufactured by FILMETRICS). . The chipping phenomenon was confirmed by atomic force microscope (AFM) Nanopics (Seiko Instruments). The results are shown in Tables 16 and 17.

Polishing machine: AVANTI472 (IPEC company product)

Polishing pad: IC1400 (K groove formation) (product made by Rohm and Haas)

Surface rotation speed: 140rpm

Carrier speed: 125rpm

Polishing processing pressure: 1.5psi

Polishing liquid feed rate: 130 ml / min

Blanket Wafer Polishing Time: 1min

Pattern Wafer Polishing Time: Time required to polish BD1 to 20nm

From Table 17, the improvement of chipping was observed by performing surface modification. Moreover, it was also confirmed from Table 16 that surface modification did not impair the polishing rate as compared with unmodified colloidal silica.

Claims (5)

Surface-modified colloidal silica characterized by surface modification by at least 1 group represented by following General formula (1), (2), and (3).

(In formula, A <^1> represents group chosen from following formula (a11)-(a13), (a31)-(a33) and (a51)-(a53), and A <^2> represents following formula (a21)-(a23) ), (a41) to (a43) and (a61) to (a63), R ³ represents a hydrogen atom or a hydrocarbon group of 1 to 30 carbon atoms, Y represents A ² or R ³ , and EO Represents an ethylene oxide group, PO represents a propylene oxide group, and m, n, and p represent a number where m is 0 to 170, n is 0 to 120, p is 0 to 170, and m + p is not zero. )

(In formula, R <^1> , R <^2> represents a C1-C4 alkyl group, a phenyl group, or a hydroxyl group, X represents a C1-C18 alkylene group, and R represents a hydrogen atom or a methyl group.) The surface-modified colloidal silica according to claim 1, wherein in formula (1), (2) or (3), m + p is a value of n or more. The surface modified colloidal silica according to claim 2, wherein m + p is in the range of 2 to 340 in the general formulas (1), (2) or (3). The surface-modified colloidal silica of any one of Claims 1-3 is contained, The polishing composition for CMP characterized by the above-mentioned. The polishing composition for CMP according to claim 4, further comprising persulfate.