JP2009004590A - Composition for chemimechanical polishing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for chemimechanical polishing capable of preventing the defect of a polishing surface by improving dispersion and providing chelate capability as well. <P>SOLUTION: By using the composition for chemimechanical polishing containing at least one kind of a compound (acyl compound) having at least two each of acyl groups and hydrophilic groups inside a molecule, the dispersion of a conventional chemimechanical polishing composition is improved, the chelate capability is provided as well, and thus the defect of the polishing surface is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a slurry-like chemical mechanical polishing composition. The chemical mechanical polishing composition of the present invention is used for planarization of, for example, a semiconductor wafer.

In recent years, integrated circuits in semiconductor manufacturing processes are increasingly required to be miniaturized and multilayered. Multi-layered wiring of semiconductor large-scale integrated circuits is a factor that increases the unevenness of semiconductors. This, combined with miniaturization of integrated circuits, leads to disconnection, lowering of electric capacity, occurrence of electromigration, etc., causing problems such as lowering of yield. Cause.
For this reason, various processing techniques for flattening metal wirings and interlayer insulating films in a multilayer wiring board have been developed so far, one of which is CMP (Chemical Mechanical Polishing) technique. The CMP technique is a technique necessary for planarizing (mirroring) an interlayer insulating film, forming a buried wiring, forming a plug, and the like in semiconductor manufacturing.
CMP is performed by rotating the carrier and the polishing pad while pressing a flat wafer made of a normal semiconductor mounted on the carrier against the wet polishing pad with a constant pressure. At this time, the convex portions of the wiring and the insulating film are polished by the polishing composition introduced between the wafer and the polishing pad, and flattening (mirror finishing) is performed.

  Conventionally, various polishing compositions and polishing methods have been proposed for polishing a metal film of a semiconductor substrate. As shown in “Semiconductor flattening CMP technology” by Toshiro Tohi et al. (July 1998, Industrial Research Committee), page 235, metal CMP oxidizes the metal surface with an oxidizing agent in the abrasive composition. However, polishing is performed with a polishing pad and abrasive grains under conditions where the metal is corroded and the pH is acidified and the metal is slightly corroded (etching). For example, as a polishing composition for a metal film such as aluminum formed on a semiconductor substrate, a polishing composition in which aluminum oxide is dispersed in an aqueous nitric acid solution having a pH of 3 or less (Patent Document 1), aluminum oxide or silicon oxide is sulfuric acid. There exists polishing composition (patent document 2) formed by mixing with acidic aqueous solution, such as nitric acid and acetic acid. Further, a polishing composition comprising an abrasive such as silicon oxide or aluminum oxide and an oxidizing agent such as hydrogen peroxide, such as a polishing composition in which aluminum oxide is dispersed in hydrogen peroxide and an aqueous phosphoric acid solution (Patent Document 3). Usually used. However, a polishing composition in which an abrasive made of a metal oxide such as silicon oxide or aluminum oxide is dispersed in an aqueous solution has a problem of surface scratches due to poor dispersibility of the abrasive itself.

  In addition, when hydrogen peroxide is used as described above, or when a metal etchant such as ammonium persulfate is used (Patent Document 4), pits and voids are generated due to excessive progress of wet etching, There was a problem in practical use. In order to improve this, a method of adding a chemical reagent (chelating agent or the like) that forms a protective film on the surface of the metal film in the polishing composition has also been proposed (Patent Documents 5 and 6). However, when such a chelating agent is used, etching is surely suppressed and the generation of pits and voids can be prevented. However, since a protective film is also formed on the portion to be polished, the polishing rate is remarkably reduced. Etc. occur. In addition, a proposal has been made to use polyoxoacids in combination with a nonionic surfactant and an anionic surfactant (Patent Document 7). However, the storage stability was still not sufficient.

Also, a polishing composition in the form of a suspension (slurry) in which a polishing agent made of silicon oxide, particularly colloidal silica or the like in a wafer polishing step is diluted with water and further added with alkali is used. At this time, various amines are added in order to increase the polishing rate (Patent Document 8). However, these amines are easily contaminated with metals themselves, and when the polishing composition (slurry) is recycled, it is easy to bring metal (especially Cu) into the composition, and as a result, silicon which is an abrasive is used. There was a problem that caused metal (Cu) contamination of the wafer, and this solution was not sufficient.

US Pat. No. 4,702,792 US Pat. No. 4,944,836 US Pat. No. 5,209,816 JP-A-6-313164 JP-A-8-83780 JP-A-11-195628 JP 2004-189894 A JP 2002-105440 A

  The present invention relates to a chemical mechanical polishing composition. The chemical mechanical polishing composition of the present invention is used, for example, for planarization (mirror finishing) of a wafer made of a semiconductor, and aims to improve the dispersibility of a conventional chemical mechanical polishing composition and to have a chelating ability. It is what.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have obtained one or more specific compounds, that is, one or more compounds (acyl compounds) having two or more acyl groups and hydrophilic groups in the molecule. By using the chemical mechanical polishing composition contained, it is found that the dispersibility of the conventional chemical mechanical polishing composition is improved and the chelating ability is also provided, whereby defects on the polished surface can be further suppressed, and the present invention is completed. It came to.

That is, the present invention is as follows.
1. A chemical mechanical polishing composition comprising one or more acyl compounds each having two or more acyl groups and hydrophilic groups in the molecule.
2. At least one of the acyl compounds has an amino acid residue in the molecule. The composition for chemical mechanical polishing described in 1.

（上記一般式（１）において、Ｘはｍ個の官能基、およびそれ以外の置換基を有していてもよい分子量１００万以下の直鎖または分枝鎖または環状鎖または芳香族炭化水素鎖であるスペーサーであり、Ｘに結合している、ｎ（ｍ≧ｎ）個のＱは、下記一般式（２）で表される置換基で、それぞれ互いに同一でも異なっていてもよく、下記一般式（２）において、ＺはＸの有する官能基に由来する結合部であり、Ｒ^１ＣＯは炭素原子数２〜２０の飽和または不飽和の脂肪酸から誘導される長鎖アシル基を示し、Ｒ^２は水素であるか、またはヒドロキシル基またはカルボキシル基が置換していてもよい炭素原子数１〜３の低級アルキル基を示し、Ｙはカルボキシル基、スルホン酸基、硫酸エステル基、リン酸エステル基および／またはそれらの塩を示し、ｊ、ｋはそれぞれ独立に０，１，２のいずれかであり、かつｊ、ｋは同時に０ではなく、ｎは２〜２０の整数を示す） 3. At least one of the acyl compounds is a compound represented by the following general formula (1): Or 2. The composition for chemical mechanical polishing described in 1.

(In the above general formula (1), X is a linear, branched, cyclic or aromatic hydrocarbon chain having a molecular weight of 1,000,000 or less, which may have m functional groups and other substituents. N (m ≧ n) Qs bonded to X are substituents represented by the following general formula (2), which may be the same as or different from each other. In Formula (2), Z is a bond derived from a functional group of X, R ¹ CO represents a long-chain acyl group derived from a saturated or unsaturated fatty acid having 2 to 20 carbon atoms, R ² represents hydrogen, or a lower alkyl group having 1 to 3 carbon atoms which may be substituted with a hydroxyl group or a carboxyl group, and Y represents a carboxyl group, a sulfonic acid group, a sulfate group, or a phosphate group. And / or their Are shown, j, k is any of independently 0,1,2, and j, k are not 0 at the same time, n represents an integer from 2 to 20)

  4). 1. A slurry dispersed in water or a mixed solvent of water and an organic solvent. ~ 3. The chemical mechanical polishing composition according to any one of the above.

  The chemical mechanical polishing composition of the present invention is used, for example, for planarization (mirroring) of a wafer made of a semiconductor, improves the dispersibility of a conventional chemical mechanical polishing composition, and has a chelating ability. It is possible to further suppress defects on the polished surface.

Hereinafter, the present invention will be specifically described focusing on its preferred form.
The chemical mechanical polishing composition of the present invention is in the form of a slurry dispersed in water or a mixed solvent of water and an organic solvent, and contains at least one acyl compound having a specific structure in the composition. It is the composition which becomes. The term “acyl compound” as used herein refers to a compound having a structure having at least two acyl groups and two or more hydrophilic groups in the molecule. Good.

The acyl groups are each independently, that is, each may be different or the same, and those derived from a saturated or unsaturated fatty acid having 2 to 20 carbon atoms are preferable, and may be linear, branched or cyclic. Absent.
For example, acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, heptanoic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid , Linear fatty acids such as nonadecanoic acid, arachidic acid;

  2-butyl-5-methylpentanoic acid, 2-isobutyl-5-methylpentanoic acid, dimethyloctanoic acid, dimethylnonanoic acid, 2-butyl-5-methylhexanoic acid, methylundecanoic acid, dimethyldecanoic acid, 2-ethyl- 3-methylnonanoic acid, 2,2-dimethyl-4-ethyloctanoic acid, methyldocosanoic acid, 2-propyl-3-methylnonanoic acid, methyltridecanoic acid, dimethyldodecanoic acid, 2-butyl-3-methylnonanoic acid, methyltetradecanoic acid , Ethyltridecanoic acid, propyldodecanoic acid, butylundecanoic acid, pentyldecanoic acid, hexylnonanoic acid, 2- (3-methylbutyl) -3-methylnonanoic acid, 2- (2-methylbutyl) -3-methylnonanoic acid, butylethylnonane Acid, methylpentadecanoic acid, ethyltetradecanoic acid, propyltri Canic acid, butyldodecanoic acid, pentylundecanoic acid, hexyldecanoic acid, heptylnonanoic acid, dimethyltetradecanoic acid, butylpentylheptanoic acid, trimethyltridecanoic acid, methylhexadecanoic acid, ethylpentadecanoic acid, propyltetradecanoic acid, butyltridecanoic acid, pentyldodecane Acid, hexylundecanoic acid, heptyldecanoic acid, methylheptylnonanoic acid, dipentylheptanoic acid, methylheptadecanoic acid, ethylhexadecanoic acid, ethylhexadecanoic acid, propylpentadecanoic acid, butyltetradecanoic acid, pentyltridecanoic acid, hexyldodecanoic acid, heptyl Undecanoic acid, octyldecanoic acid, dimethylhexadecanoic acid, methyloctylnonanoic acid, methyloctadecanoic acid, ethylheptadecanoic acid, dimethylheptadecanoic acid, Octyl decanoic acid, Mechirunonadekan acid, Mechirunonadekan acid, dimethyl octadecanoic acid, branched fatty acids such as butyl heptyl nonanoic acid;

Octenoic acid, nonenoic acid, decenoic acid, caproleic acid, undecylenic acid, Lindellic acid, touric acid, lauroleic acid, tridecenoic acid, tuzuic acid, myristoleic acid, pentadecenoic acid, hexedenoic acid, palmitoleic acid, heptadecenoic acid, octadecenoic acid, Linear monoenoic acids such as oleic acid, nonadecenoic acid, gondoic acid;
Such as methylheptenoic acid, methylnonenoic acid, methylundecenoic acid, dimethyldecenoic acid, methyldodecenoic acid, methyltridecenoic acid, dimethyldodecenoic acid, dimethyltridecenoic acid, methyloctadecenoic acid, dimethylheptadecenoic acid, ethyloctadecenoic acid Branched monoenoic acid;

Di- or trienoic acids such as linoleic acid, linoleic acid, eleostearic acid, linolenic acid, linolenic elaidic acid, pseudoeleostearic acid, parinaric acid, arachidonic acid;
Acetylene acids such as octinoic acid, nonionic acid, decinic acid, undecinic acid, dodecinic acid, tridecic acid, tetradecic acid, pentadecinic acid, heptadesinic acid, octadecinic acid, nonadesinic acid, dimethyloctadesinic acid;
Of methyleneoctadecenoic acid, methyleneoctadecanoic acid, aleprolic acid, alepresinic acid, allepuric acid, alepuric acid, hydonocarpic acid, schoalmoulinic acid, gorulic acid, α-cyclopentylic acid, α-cyclohexylic acid, α-cyclopentylethylic acid And acyl groups derived from such cyclic acids.

  Moreover, the acyl group derived from the fatty acid obtained from natural fats and oils may be sufficient, and the acyl group derived from the mixed fatty acid containing 80% or more of the saturated or unsaturated fatty acid having 2 to 20 carbon atoms is preferable. For example, acyl groups derived from coconut oil fatty acid, palm oil fatty acid, linseed oil fatty acid, sunflower oil fatty acid, soybean oil fatty acid, sesame oil fatty acid, castor oil fatty acid, olive oil fatty acid, camellia oil fatty acid, rapeseed oil fatty acid, palm kernel oil fatty acid, etc. Etc. Two or more of these acyl compounds may be used in combination. The acyl group preferably has 8 to 20 carbon atoms.

  In the chemical mechanical polishing composition of the present invention, the acyl compound and the hydrophilic group are each independently a carboxyl group, a sulfonic acid group, a sulfuric acid residue, a phosphoric acid residue or a salt thereof, or an oxyalkylene group, It has a polyethylene glycol group or the like, or an amino group, a quaternary ammonium group, a pyridinium group, a sulfonium group or a salt thereof. The hydrophilic group of the acyl compound is preferably each independently a carboxyl group, a sulfonic acid group, a sulfate ester group, a phosphate ester group and / or a salt thereof.

  When the acyl compound is used as a salt, examples thereof include alkali metal salts, alkaline earth metal salts, ammonium salts, organic amine salts, basic amino acid salts, and the like. Specifically, alkalis such as sodium, potassium, and lithium are used. Arbitrary metals such as metals, alkaline earth metals such as calcium and magnesium, metals such as aluminum and zinc, organic amines such as ammonia, monoethanolamine, diethanolamine, triethanolamine and triisopropanolamine, and basic amino acids such as arginine and lysine It is a salt with 1 type, or 2 or more types chosen by these. Among these, sodium salts, potassium salts, organic amine salts, and basic amino acid salts are particularly preferable.

In the chemical mechanical polishing composition of the present invention, at least one of the acyl compounds contained in the chemical mechanical polishing composition is an acyl compound represented by the general formula (1) and the general formula (2). preferable.
The acyl compound here is structurally a compound having at least one acyl group and a hydrophilic group in the molecule with an appropriate spacer as shown in the general formula (1) and the general formula (2). It has a connected structure.

In the above general formula (2), the acyl groups represented by R ¹ CO are independent, that is, they may be different or the same, and are derived from a saturated or unsaturated fatty acid having 2 to 20 carbon atoms as described above. Any of straight-chain, branched, and cyclic structures can be used.
In the general formula (2), the acyl group represented by R ¹ CO is preferably derived from a saturated or unsaturated fatty acid having 8 to 20 carbon atoms.
In the general formula (2), R ² is hydrogen, or the number of carbon atoms that may be substituted by a hydroxyl group or a carboxyl group, a sulfonic acid group, a sulfate ester group, a phosphate ester group, or a salt thereof. 1 to 3 lower alkyl groups, for example, methyl group, ethyl group, propyl group, isopropyl group, hydroxymethyl group, hydroxyethyl group, hydroxy (iso) propyl group, dihydroxy (iso) propyl group, carboxymethyl group, A carboxyethyl group, a carboxypropyl group, a sulfoethyl group, etc. are mentioned.
In the general formula (1), n substituents Q bonded to X (the above general formula (2)) may be different from each other or the same. Moreover, the said General formula (2) shows what the so-called acidic amino acid was N-acylated, and it does not ask | require whether they are optical isomers, for example, D-form, L-form, and a racemate.

  The acidic amino acid is a monoaminodicarboxylic acid having 2 and 1 carboxyl groups and 1 amino group, respectively, in the molecule, and the amino group may be an N-methyl group or an N-ethyl group. It does not matter whether it is an optical isomer, for example, a D-form, an L-form, or a racemate. Examples of acidic amino acids include glutamic acid, aspartic acid, lanthionine, β-methyllanthionine, cystathionine, diencholic acid, ferrinin, aminomalonic acid, β-oxyaspartic acid, α-amino-α-methylsuccinic acid, β-oxyglutamic acid. , Γ-oxyglutamic acid, γ-methylglutamic acid, γ-methyleneglutamic acid, γ-methyl-γ-oxyglutamic acid, α-aminoadipic acid, α-amino-γ-oxyadipic acid, α-aminopimelic acid, α-amino- Examples thereof include γ-oxypimelic acid, β-aminopimelic acid, α-aminosuberic acid, α-aminosebacic acid, pantothenic acid and the like.

The n substituents (the above general formula (2)) attached to X are preferable because the acidic amino acid is an L-acidic amino acid molecule because it is excellent in biodegradability.
In the above general formula (2), Z represents a bonding portion (-) derived from m functional groups (hydroxyl group, amino group, thiol group) substituted with X (m ≧ n and an integer of 2 to 20). ^{O -, - NR 3 -,} - it is S-). Here, R ³ is hydrogen, or an alkyl group, alkenyl group, aryl group or alkylaryl group having 1 to 10 carbon atoms.

In the general formula (1), X is a linear, branched or cyclic chain having a molecular weight of 1 million or less and having m functional groups consisting of one or more selected from a hydroxyl group, an amino group and a thiol group. Or it is a spacer which is an aromatic hydrocarbon chain | strand, and X may have substituents other than the said hydroxyl group, an amino group, and a thiol group.
In the general formula (1), X is preferably a residue of an m-valent compound having a molecular weight of 1 million or less and having m functional groups of one kind or two or more kinds selected from a hydroxyl group, an amino group and a thiol group. And a compound residue that may have a substituent other than a hydroxyl group, an amino group, and a thiol group. Here, the m-valent compound means that a bond derived from m functional groups can be formed. It does not matter whether they are optical isomers such as D-form, L-form, and racemate.

Examples of such m-valent compounds include amino acids such as serine, threonine, cysteine, cystine, cystine disulfoxide, cystathionine, methionine, arginine, lysine, tyrosine, histidine, tryptophan, and oxyproline;
Aminoethanol, aminopropanol, aminobutanol, aminopentanol, aminohexanol, aminopropanediol, aminoethylethanolamine, aminoethylaminoethanol, aminocresol, aminonaphthol, aminonaphtholsulfonic acid, aminohydroxybenzoic acid, aminohydroxybutanoic acid Compounds having an amino group and a hydroxyl group in the molecule such as aminophenol, aminophenethyl alcohol, glucosamine;

Compounds having a thiol group and a hydroxyl group in the molecule such as mercaptoethanol, mercaptophenol, mercaptopropanediol, glucothiose;
Compounds having a thiol group and an amino group in the molecule such as aminothiophenol and aminotriazole thiol;
Is mentioned. Further, proteins, peptides, etc., or those obtained by hydrolyzing them may be used.

In the general formula (1), X is preferably an m-valent (m ≧ n) polyhydroxyl compound residue having a molecular weight of 1,000,000 or less, which may have a substituent other than a hydroxyl group. Here, the m-valent polyhydroxyl compound means that m ester bonds can be formed. It does not matter whether they are optical isomers such as D-form, L-form, and racemate.
Examples of such m-valent polyhydroxyl compounds include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butanediol. , Pentanediol, 1,6-hexanediol, cyclohexanediol, dimethylolcyclohexane, neopentyl glycol, 1,8-octanediol,

2,2,4-trimethyl-1,3-pentanediol, isoprene glycol, 3-methyl-1,5-pentanediol, sorbite, catechol, resorcin, hydroquinone, bisphenol A, bisphenol F, hydrogenated bisphenol A, hydrogenated Bisphenol F,
Dimerdiol, dimethylolpropionic acid, dimethylolbutanoic acid, tartaric acid, dihydroxytartaric acid, mevalonic acid, 3,4-dihydroxycinnamic acid, 3,4-dihydroxyhydrocinnamic acid, hydroxybenzoic acid, dihydroxystearic acid, dihydroxyphenylalanine And divalent hydroxyl compounds such as each of these isomers;

Glycerin, trioxyisobutane, 1,2,3-butanetriol, 1,2,3-pentanetriol, 2-methyl-1,2,3-propanetriol, 2-methyl-2,3,4-butanetriol, 2-ethyl-1,2,3-butanetriol, 2,3,4-pentanetriol,
2,3,4-hexanetriol, 4-propyl-3,4,5-heptanetriol, 2,4-dimethyl-2,3,4-pentanetriol, 1,2,4-butanetriol, 1,2, Trivalent polyhydroxyl compounds such as 4-pentanetriol, trimethylolethane, trimethylolpropane, diethanolamine, triethanolamine, trihydroxystearic acid;

Pentaerythritol, erythritol, 1,2,3,4-pentanetetrol, 2,3,4,5-hexanetetrol, 1,2,4,5-pentanetetrol, 1,3,4,5-hexane Tetravalent polyhydroxyl compounds such as tetrol, diglycerin and sorbitan;
Pentavalent polyhydroxyl compounds such as adonitol, arabitol, xylitol, triglycerin;
Hexavalent polyhydroxyl compounds such as dipentaerythritol, sorbitol, mannitol, iditol, inositol, dulcitol, talose, allose;
Or these dehydration condensates, polyglycerol, etc. are mentioned.

Sugars such as tetroses such as erythrose, sreose, erythrulose;
Pentose such as ribose, arabinose, xylose, lyxose, xylulose, ribulose; monosaccharides such as hexose such as allose, altrose, glucose, mannose, guylose, idose, galactose, talose, fructose, sorbose, psicose, tagatose;
Examples thereof include oligosaccharides such as maltose, isomaltose, cellobiose, gentiobiose, melibiose, lactose, tulanose, trehalose, saccharose, mannitolose, cellotriose, gentianose, raffinose, meletitose, cellotetorose, stachyose and the like.

In addition, other saccharides such as heptose, deoxy sugar, amino sugar, thio sugar, seleno sugar, aldone sugar, uronic acid, sugar acid, ketoaldonic acid, anhydro sugar, unsaturated sugar, sugar ester, sugar ether, glycoside, etc. It may be a group, and may be a polysaccharide such as starch, glycogen, cellulose, chitin, chitosan or the like, or a hydrolyzed product thereof.
In the general formula (1), X is preferably an m-valent polyamino compound residue having a molecular weight of 1,000,000 or less, which may have a substituent other than an amino group. Here, the m-valent polyamino compound means that m acid amide bonds can be formed. It does not matter whether they are optical isomers such as D-form, L-form, and racemate.

Examples of such m-valent polyamino compounds include N, N′-dimethylhydrazine, ethylenediamine, N, N′-dimethylethylenediamine, diaminopropane, diaminobutane, diaminopentane, diaminohexane, diaminoheptane, diaminooctane, diaminononane, Aliphatic diamines such as diaminodecane, diaminododecane, diaminoadipic acid, diaminopropanoic acid, diaminobutanoic acid and their isomers;
Diethylenetriamine, triaminohexane, triaminododecane, 1,8-diamino-4-aminomethyl-octane, 2,6-diaminocapric acid-2-aminoethyl ester, 1,3,6-triaminohexane, 1,6 , 11-triaminoundecane, aliphatic triamines such as di (aminoethyl) amine and isomers thereof;

Alicyclic polyamines such as diaminocyclobutane, diaminocyclohexane, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, triaminocyclohexane;
Aromatic polyamines such as diaminobenzene, diaminotoluene, diaminobenzoic acid, diaminoanthraquinone, diaminobenzenesulfonic acid, diaminobenzoic acid, and their respective isomers;
Araliphatic polyamines such as diaminoxylene, di (aminomethyl) benzene, di (aminomethyl) pyridine, di (aminomethyl) naphthalene, and their isomers;
And polyamines substituted with hydroxyl groups such as diaminohydroxypropane and isomers thereof.

In the general formula (1), X is preferably an m-valent polythiol compound residue having a molecular weight of 1,000,000 or less, which may have a substituent other than a thiol group. Here, the m-valent polythiol compound means that m thioester bonds can be formed. It does not matter whether they are optical isomers such as D-form, L-form, and racemate.
Examples of such m-valent polythiol compounds include dithiol compounds such as dithioethylene glycol, dithioerythritol, and dithiothreitol.
X is preferably a group having 1 to 40 carbon atoms among the residues of the compounds listed above, and more preferably X has 1 to 20 carbon atoms. X is preferably a naturally occurring type from the viewpoint of excellent biodegradability.

In the general formula (2), a carboxyl group represented by Y, a sulfonic acid group, a sulfuric ester group, a phosphoric ester group, and a carboxyl group, a sulfonic acid group, a sulfuric ester group, a phosphoric ester group, etc. that can be contained in X Can form salts with various basic substances as described above.
As a method for producing the acyl compound represented by the general formula (1) and the general formula (2), an N-acyl acidic amino acid anhydride represented by the following general formula (3) and a hydroxyl group in the molecule, By reacting a compound having one or more m functional groups selected from an amino group and a thiol group in water and / or a mixed solvent of water and an organic solvent, or tetrahydrofuran, benzene, It can be obtained by reacting by using an inert solvent such as toluene, xylene, carbon tetrachloride, chloroform, acetone, or by mixing at -5 ° C to 200 ° C at a temperature higher than any melting point without solvent. it can.

  Alternatively, the acyl compound represented by the general formula (1) and the general formula (2) is an N-acyl acidic amino acid mono-lower ester (for example, methyl ester, ethyl ester) and a polyhydroxyl compound, a polyamino compound, or a polythiol compound, or A compound having any two or three of hydroxyl group, amino group, and thiol group in the molecule is dissolved in a suitable solvent such as dimethylformamide, a catalyst such as potassium carbonate is added, and -5 is added under reduced pressure. It can be obtained by removing the reaction solvent after heating at 250 ° C. to 250 ° C. Alternatively, the acyl compound can be obtained by melting with heating without a solvent, adding a catalyst such as sodium hydroxide, and performing a transesterification reaction at room temperature to 250 ° C.

The chemical mechanical polishing composition of the present invention is finally used as a slurry by using water or a mixed solvent of water and an organic solvent as a solvent. However, as a general method of use, at least one acyl compound having two or more acyl groups and hydrophilic groups in the molecule, which is characteristic in the present invention, is contained in a polishing liquid containing various chemical components. Alternatively, it may be contained in a slurry containing a hard fine abrasive.
In the chemical mechanical polishing composition of the present invention, the type and amount of the abrasive used are not particularly limited. For example, phosphovanadomolybdic acid (PVM), silicon oxide (including colloidal silica), aluminum oxide, diamond , Cubic boron, silicon carbide and the like or a mixture thereof can be used in an amount of 0.1 to 30 parts by weight, preferably 1.0 to 15 parts by weight, per 100 parts by weight of the composition. These abrasives can be used alone, in combination or in a mixture. The average particle diameter of the abrasive is also not particularly limited according to the application and purpose.

In the chemical mechanical polishing composition of the present invention, if necessary, polishing rate improvers such as amines, nonionic surfactants and anionic surfactants are used. However, there is no particular limitation, and it may be within the usual range. In particular, the amount of each used may be 0.1 to 30 parts by weight, preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the composition.
If necessary, alcohols such as methanol, ethanol, n-butanol, iso-butanol, tertiary butanol, glycerin, and ethylene glycol can be added to the chemical mechanical polishing composition of the present invention. In addition, known inorganic acids such as sulfuric acid, phosphoric acid, nitric acid and the like, or known organic acids such as malic acid, citric acid, oxalic acid and acetic acid can also be used.

  In the chemical mechanical polishing composition of the present invention, the acyl compound is preferably 0.001 to 15 parts by weight of the acyl compound with respect to 100 parts by weight of the chemical mechanical polishing composition. When the proportion of the acyl compound is less than 0.001 part by weight, the dispersion effect may not be sufficiently obtained, and when it exceeds 15 parts by weight, the composition viscosity may increase. More preferably, the acyl compound is 0.01 to 7 parts by weight per 100 parts by weight of the chemical mechanical polishing composition.

The chemical mechanical polishing composition of the present invention can be produced by a known method, for example, by the following method.
The acyl compound and other components as described above can be produced using a stirrer, a kneader such as a homogenizer or a kneader, a crusher, or the like.
In particular, a slurry liquid can be produced by mixing and stirring at least one acyl compound and abrasive powder in an aqueous medium composed of water or a mixed medium of water and an organic solvent.
Hereinafter, the present invention will be described more specifically using examples and the like, but the present invention is not limited to these examples and the like.

(Production Example 1 of acyl compound)
9.1 g (0.05 mol) of L-lysine hydrochloride was dissolved in 57 g of water. While adjusting this solution to a pH range of 10-11 with a 25% aqueous sodium hydroxide solution and maintaining the reaction temperature at 5 ° C., 31.1 g (0.1 mol) of N-lauroyl-L-glutamic anhydride was added with stirring. ) Was added over 2 hours to carry out the reaction. After stirring for another 30 minutes, tertiary butanol was added to a concentration of 20% by weight in the liquid, 75% sulfuric acid was added dropwise to bring the liquid pH value to 2, and the liquid temperature to 65 ° C. It was adjusted. After completion of the dropwise addition, stirring was stopped, and the mixture was allowed to stand at 65 ° C. for 20 minutes. Tertiary butanol and water were added to the separated organic layer, the temperature was raised to 65 ° C., and the mixture was stirred for 20 minutes. After the stirring was stopped, the mixture was allowed to stand to separate into an organic layer and an aqueous layer. After repeating the same water washing operation with respect to the obtained organic layer, the solvent was removed from the obtained organic layer and dried to obtain an acyl compound represented by the following general formula (4).

(Production Example 2 of acyl compound)
The same procedure as in Production Example 1 was carried out except that N-lauroyl-L-glutamic anhydride was changed to N-cocoyl-L-glutamic anhydride (0.1 mol) in Production Example 1 to obtain an acyl compound. It was.
(Acyl Compound Production Example 3)
In Production Example 1, N-lauroyl-L-glutamic anhydride (0.1 mol) was changed to N-stearoyl-L-glutamic anhydride (0.1 mol), and the reaction temperature was 20 ° C. The reaction was carried out under the same conditions as in the method to obtain an acyl compound.

[Example 1]
Phosphovanadomolybdic acid: PVMo (trade name: PVM-1-11 manufactured by Nippon Inorganic Chemical Industry Co., Ltd.) 12 g was dispersed in 176 g of water, stirred with a homogenizer, and polyoxyethylene synthetic alcohol ether as a nonionic surfactant: SF-1 (Brand name BLAUNON
After adding 8 g of DAL-5 (Aoki Yushi Kogyo Co., Ltd.), 4 g of dodecylbenzenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd.) is added as an anionic surfactant. 5g was added and the slurry of the abrasive | polishing agent composition was obtained.

[Example 2]
In Example 1, instead of acyl compound production example 1, 0.4 g of acyl compound production example 2 was added to obtain a slurry of an abrasive composition.
[Example 3]
N- (β-aminoethyl) ethanolamine (polishing speed improver) per liter of the slurry was added to a slurry of an abrasive composition containing 2.5% by weight of silicon oxide having an average particle size of 50 nm (solvent is water). 0.008 mol was added, and finally 0.03% by weight of Production Example 3 of an acyl compound was contained, and the pH was adjusted to 11.1.

[Comparative Example 1]
A slurry of the abrasive composition was obtained in exactly the same manner as in Example 1 except that Production Example 1 of the acyl compound was not added. 0.5 g was added.
[Comparative Example 2]
In Comparative Example 1, a slurry of an abrasive composition was obtained in exactly the same manner as Comparative Example 1, except that the nonionic surfactant SF-1 was not used.
[Comparative Example 3]
In Example 3, a slurry of the abrasive composition was obtained in the same manner as in Example 3 except that Production Example 3 of acyl compound was not added.

The evaluation means used in the examples of the present invention are as follows.
(Polishing rate measurement; Examples 1 and 2, Comparative Examples 1 and 2)
The change in each film thickness before and after polishing was calculated by dividing by the polishing time. The polishing conditions are: polishing pressure 50 g / cm ² , relative speed between substrate and polishing pad 50 m / min, IC1400A21 (manufactured by Nitta Haas) dressed with a number 100 dresser as the polishing pad, and the polishing pad A silicon wafer with a copper film (thickness: 1 μm) was polished while dropping the chemical mechanical polishing composition.

(Polishing rate measurement; Example 3, Comparative Example 3)
A silicon wafer having a diameter of 150 nm that was subjected to an etching process in a general wafer manufacturing process was polished under the same polishing conditions as in Examples 1 and 2.
(Surface defect (scratch evaluation))
After the polished silicon wafer was washed and dried, a spotlight was applied to the surface of the semiconductor wafer in a dark room, and the presence or absence of scratches was visually determined.

(Dishing performance evaluation by etching rate measurement)
By evaluating the wet etching property, which is the cause of dishing, an alternative evaluation of dishing property was made. Since dishing is caused by erosion of the metal film due to excessive chemical action (wet etching) of the abrasive composition, the etching rate of the abrasive composition, which is the main cause of dishing, is reduced. The evaluation here was to evaluate the dishing characteristics as a result. Specifically, a silicon wafer with a copper film (thickness: 1 μm) is immersed in the polishing composition for a certain period of time, and the change in film thickness before and after the immersion is measured, and the etching rate is obtained by dividing this by the immersion time. The dishing characteristics were evaluated according to the following criteria (◎ to ×). The slower the etching rate, the weaker the wet etching property and the less likely dishing occurs.
A: Etching rate less than 3 nm / min O: Etching rate less than 3-10 nm / min Δ: Etching rate 10-50 nm / min
×: Etching rate 50 nm / over

(Storage stability of chemical mechanical polishing composition)
In Example 3 and Comparative Example 3, since the amine (polishing rate improver) that easily causes the problem of copper contamination described in Patent Document 8 is used, the composition for chemical mechanical polishing on the surface of the polished silicon wafer is used. As the storage stability evaluation after standing at 40 ° C. for 3 months, the following determination was made.
○: Change rate of polishing rate and etching rate is less than 5% Δ: Change rate of polishing rate and etching rate is 5% or more and less than 20% ×: Change rate of polishing rate and etching rate is 20% or more

(Measurement of copper on the surface of silicone wafers)
The amount of copper was measured using VPD-AAS (Vapor Phase Decomposition a
nd Atomic Absorption Spectroscopy).
Table 1 shows the evaluation results of the polishing rate relative value, scratch evaluation, dishing evaluation, and storage stability of Example 1, Example 2, Comparative Example 1, and Comparative Example 2. Table 2 shows the polishing rate relative values, scratch evaluation, and surface copper (Cu) concentration of Example 3 and Comparative Example 3.

  The chemical mechanical polishing composition of the present invention is suitable for use in, for example, planarization of a wafer made of a semiconductor due to its dispersion force and chelating action.

Claims (4)

  A chemical mechanical polishing composition comprising one or more acyl compounds each having two or more acyl groups and hydrophilic groups in the molecule.   The chemical mechanical polishing composition according to claim 1, wherein at least one of the acyl compounds has an amino acid residue in the molecule. The chemical mechanical polishing composition according to claim 1 or 2, wherein at least one of the acyl compounds is a compound represented by the following general formula (1).

(In the above general formula (1), X is a linear, branched, cyclic or aromatic hydrocarbon chain having a molecular weight of 1,000,000 or less, which may have m functional groups and other substituents. N (m ≧ n) Qs bonded to X are substituents represented by the following general formula (2), which may be the same as or different from each other. In Formula (2), Z is a bond derived from a functional group of X, R ¹ CO represents a long-chain acyl group derived from a saturated or unsaturated fatty acid having 2 to 20 carbon atoms, R ² represents hydrogen, or a lower alkyl group having 1 to 3 carbon atoms which may be substituted with a hydroxyl group or a carboxyl group, and Y represents a carboxyl group, a sulfonic acid group, a sulfate group, or a phosphate group. And / or their Are shown, j, k is any of independently 0,1,2, and j, k are not 0 at the same time, n represents an integer from 2 to 20)

  The chemical mechanical polishing composition according to any one of claims 1 to 3, wherein the composition is a slurry dispersed in water or a mixed solvent of water and an organic solvent.