JP6728011B2 - Polishing composition for CMP and method for manufacturing semiconductor device using the polishing composition for CMP - Google Patents

Description

The present invention provides a chemical mechanical polishing abrasive composition (hereinafter sometimes referred to as “CMP abrasive composition”) most suitable for surface flattening of wafers and liquid crystal display substrates in the semiconductor industry and the like. And a method for producing a semiconductor device polished by using the CMP polishing composition. It should be noted that “CMP” means chemical mechanical polishing in which chemical polishing for planarizing the surface of a wafer or the like and mechanical polishing are combined.

At present, semiconductor devices tend to be highly integrated and miniaturized. The semiconductor device is formed by, for example, projecting a pattern on the surface of a wafer obtained by cutting an ingot and polishing it with ultraviolet light having a wavelength of about 193 nm, and forming an element such as a transistor by a process such as film formation and etching. A film is formed by CVD (Chemical Vapor Deposition), etc., a pattern of projections and depressions of the film is flattened, a pattern is exposed by light, and a pattern is removed by etching. To be done. The number of transistors and other elements formed on the upper surface of the wafer is enormous, and the wiring to connect them is multi-layered, but each layer is stacked as designed to prevent disconnection of wiring and local increase in resistance. In order to suppress and prevent disconnection or reduction in current capacity, it is important to flatten the surface after the film formation step to eliminate irregularities.

CMP is widely used as this flattening technique, and it is known that a surfactant is added to an abrasive composition used for CMP for the purpose of improving surface accuracy after polishing. In Patent Document 1, by adding a polyoxyalkylene derivative as a surfactant, low scratching property and good cleaning property are obtained, and an object to be polished is suppressed while suppressing occurrence of scratches on the wafer surface. It is described that the surface of can be highly accurately flattened and polishing debris can be removed by washing with water after polishing. However, it was still insufficient in terms of suppressing scratches.

Patent Document 2 describes that low scratch resistance can be improved by using polyglycerin or polyglycerin monoether as a surfactant. However, it is difficult to remove polyglycerin monoether by washing with water, and since it is difficult to disperse or dissolve it in an organic solvent, it cannot be easily removed even by washing with an organic solvent. Remaining may cause wafer defects. This problem became apparent as the miniaturization of wiring progressed.

JP, 2003-176479, A JP, 2009-99819, A

Therefore, an object of the present invention is to polish a wafer without causing scratches, and after the polishing is completed, it can be easily removed from the wafer surface by washing with water and an organic solvent. To provide things.

As a result of intensive studies for solving the above-mentioned problems, the present inventor has found that an abrasive composition for CMP containing a specific polyglycerin derivative can suppress the agglomeration of the abrasive and reduce the scratches generated on the surface of the wafer. It was found that it can be removed from the wafer surface easily by washing with water and using an organic solvent, and that it is possible to suppress the presence of abrasives, polishing debris, additives, etc. on the wafer surface after cleaning. It was The present invention has been completed based on these findings.

で表される。Ｒは同一又は異なって、水素原子、炭素数１〜１８の炭化水素基、又は炭素数２〜２４のアシル基を示す。但し、（ｎ＋２）個のＲのうち、少なくとも２個は炭素数１〜１８の炭化水素基及び／又は炭素数２〜２４のアシル基である。ｎは前記繰り返し単位の数を示し、２〜６０の整数である）
で表されるポリグリセリン誘導体（Ａ）、研磨材（Ｂ）、及び水（Ｃ）を含有する化学的機械的研磨用研磨材組成物を提供する。 That is, the present invention provides the following formula (a)
_{RO- (C 3 H 5 O 2} R) n -R (a)
(In the formula, repeating units shown in parentheses are represented by the following formula (1) and/or (2)

It is represented by. R is the same or different and represents a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an acyl group having 2 to 24 carbon atoms. However, among (n+2) R, at least 2 is a hydrocarbon group having 1 to 18 carbon atoms and/or an acyl group having 2 to 24 carbon atoms. n represents the number of the repeating unit and is an integer of 2 to 60)
There is provided a chemical mechanical polishing abrasive composition containing a polyglycerin derivative (A) represented by, an abrasive (B), and water (C).

In the present invention, the polyglycerin derivative (A) is represented by the formula (a), and 25 to 95% of (n+2) Rs in the formula (a) are hydrocarbon groups having 1 to 18 carbon atoms. And/or a compound which is an acyl group having 2 to 24 carbon atoms, for use in the above-mentioned chemical/mechanical polishing abrasive composition.

The present invention also provides the aforementioned abrasive composition for chemical mechanical polishing, wherein the content of the polyglycerin derivative (A) is 0.5 to 10 parts by weight with respect to 1 part by weight of the abrasive (B). I will provide a.

The present invention also provides the aforementioned chemical mechanical polishing, wherein the abrasive (B) is at least one compound selected from the group consisting of silicon dioxide, aluminum oxide, cerium oxide, silicon nitride, and zirconium oxide. An abrasive composition for use is provided.

The present invention also provides a method for manufacturing a semiconductor device, which comprises a step of polishing a wafer using the above chemical/mechanical polishing composition.

In the abrasive composition for CMP of the present invention, the polyglycerin derivative (A) relaxes the cohesiveness of the abrasive (B) and the abrasive (B) aggregates to form secondary particles having a large particle size. It is possible to suppress the occurrence of scratches, suppress occurrence of scratches on the wafer surface, and planarize the wafer surface with high accuracy. Further, since the polyglycerin derivative (A) has excellent solubility in an organic solvent, it is possible to easily remove abrasives and debris from the wafer surface by washing with water and washing with an organic solvent after polishing. Can be removed.

FIG. 3 is a schematic side view showing an example of a polishing machine used for polishing a wafer in the method for manufacturing a semiconductor device of the present invention.

[Polyglycerin derivative (A)]
The polyglycerin derivative (A) of the present invention is represented by the following formula (a).
_{RO- (C 3 H 5 O 2} R) n -R (a)

で表される。前記［（Ｃ₃Ｈ₅Ｏ₂Ｒ）_n］が式（１）で表される繰り返し単位と式（２）で表される繰り返し単位を共に有する場合、これらの繰り返し単位の結合方法としては特に制限がなく、例えば、ブロック結合、ランダム結合、交互結合、グラフト結合等のいずれであってもよい。 In the formula (a), the repeating unit shown in parentheses is the following formula (1) and/or (2)

It is represented by. When the above [(C ₃ H ₅ O ₂ R) _n ] has both the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2), as a method of bonding these repeating units, There is no limitation, and for example, any of block bond, random bond, alternating bond, graft bond and the like may be used.

In formula (a), R is the same or different and represents a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an acyl group having 2 to 24 carbon atoms. However, at least two of all R's in the formula (a), that is, (n+2) R's are a hydrocarbon group having 1 to 18 carbon atoms and/or an acyl group having 2 to 24 carbon atoms.

The hydrocarbon group having 1 to 18 carbon atoms in R includes an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, and an alkapolyenyl group having 2 to 18 carbon atoms, and 3 to 18 carbon atoms. It includes an alicyclic hydrocarbon group, an aromatic hydrocarbon group having 6 to 18 carbon atoms, and a group in which two or more of these are linked.

Examples of the alkyl group having 1 to 18 carbon atoms include methyl, ethyl, n-propyl, 2-methyl-1-propyl, n-butyl, t-butyl, 3,3-dimethyl-2-butyl and n-. Pentyl, isopentyl, t-amyl, n-hexyl, 2-ethylhexyl, n-octyl, isooctyl, n-decyl, 4-decyl, isodecyl, dodecyl (n-lauryl), isododecyl, n-hexyldecyl, 2-hexyldecyl. Examples thereof include linear or branched alkyl groups such as tetradecyl, myristyl, isomyristyl, cetyl, isocetyl, stearyl, and isostearyl groups. Among these, a linear or branched alkyl group having 8 to 18 carbon atoms is preferable.

Examples of the alkenyl group having 2 to 18 carbon atoms include linear or branched alkenyl groups such as vinyl, allyl, 2-butenyl, propenyl, hexenyl, 2-ethylhexenyl and oleyl groups.

Examples of the alkapolyenyl group having 2 to 18 carbon atoms include butadienyl, pentadienyl, hexadienyl, heptadienyl, octadienyl, linoleyl, linolyl and other alkadienyl groups; 1,2,3-pentatrienyl and other alkatrienyl groups. An alkatetraenyl group may be mentioned.

Examples of the alicyclic hydrocarbon group having 3 to 18 carbon atoms include saturated or unsaturated alicyclic hydrocarbon groups such as cyclobutyl, cyclopentyl, cyclohexyl, cyclooctyl, cyclododecyl, 2-cycloheptenyl and 2-cyclohexenyl groups. A group (in particular, a cycloalkyl group and a cycloalkenyl group) can be mentioned.

Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include phenyl and naphthyl groups.

Examples of the group in which two or more of the above groups are linked include a benzyl, 2-phenylethenyl, 1-cyclopentylethyl, 1-cyclohexylethyl, cyclohexylmethyl, 2-cyclohexylethyl, 1-cyclohexyl-1-methylethyl group and the like. Are listed.

Examples of the acyl group having 2 to 24 carbon atoms include an aliphatic acyl group and an aromatic acyl group. Examples of the aliphatic acyl group include acetyl, propionyl, butyryl, isobutyryl, stearoyl and oleoyl groups. And saturated or unsaturated aliphatic acyl groups. Examples of the aromatic acyl group include benzoyl, toluoyl and naphthoyl groups.

R is, inter alia, a hydrogen atom, a linear or branched alkyl group (among others, a branched alkyl group having 8 to 18 carbon atoms, particularly a branched alkyl group having 8 to 15 carbon atoms), or a fat Group acyl groups (in particular, saturated aliphatic acyl groups having 10 to 18 carbon atoms) are preferable.

In the formula (a), n represents the number of repeating units (degree of polymerization) shown in the parentheses. n is an integer of 2 to 60, preferably 4 to 40, particularly preferably 10 to 30, and most preferably 15 to 25. When n is less than 2, hydrophilicity becomes too low, and it tends to be difficult to wash with water. On the other hand, when n is larger than 60, the lipophilicity becomes too low and it tends to be difficult to wash with an organic solvent.

The weight average molecular weight of the polyglycerin derivative (A) in the present invention is, for example, 200 to 20000, preferably 600 to 15000, more preferably 1000 to 10000, particularly preferably 1500 to 5000, and most preferably 2000 to 4500. When the weight average molecular weight is in the above range, the surface activity and workability tend to be improved. The weight average molecular weight in the present specification is a standard polystyrene equivalent molecular weight measured by gel permeation chromatography (GPC).

The polyglycerin derivative (A) in the present invention is, among others, represented by the above formula (a), and at least two of (n+2) Rs in the formula (a) are carbonized with 1 to 18 carbon atoms. A hydrogen group and/or an acyl group having 2 to 24 carbon atoms, and of (n+2) R, for example, 25 to 95% (preferably 30 to 90%, particularly preferably 40 to 90%) R is A compound which is a hydrocarbon group having 1 to 18 carbon atoms and/or an acyl group having 2 to 24 carbon atoms is preferable, and in particular, 25 to 95% (preferably, preferably) of (n+2) R in the formula (a). 30 to 90%, particularly preferably 40 to 90%) is a compound having a hydrocarbon group having 1 to 18 carbon atoms, and 25 to 60% (preferably preferably) of (n+2) R in the formula (a). 30 to 55%, particularly preferably 40 to 55%) is preferably at least one compound selected from compounds having an acyl group having 2 to 24 carbon atoms.

The polyglycerin derivative (A) in the present invention can be produced by various methods. Examples of the method for producing the polyglycerin derivative (A) include the following methods.
(1) Method for adding glycidyl ether derivative to (poly)glycerin (2) Method for condensing polyglycerin with alkyl halide, carboxylic acid, or carboxylic acid derivative (for example, carboxylic acid halide, acid anhydride, etc.)

In the above method (1), the addition reaction is preferably carried out in the presence of an alkali catalyst. Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, lithium hydroxide, metallic sodium, sodium hydride and the like. These can be used individually by 1 type or in combination of 2 or more types.

Examples of the polyglycerin in the above methods (1) and (2) include, for example, trade names “PGL 03P” (poly(3) glycerin), “PGL 06” (poly(6) glycerin), and “PGL 10PSW” (poly( Commercially available products such as 10) glycerin), “PGL 20PW” (poly(20) glycerin), “PGL XPW” (poly(40) glycerin) (above, manufactured by Daicel Corporation) can be preferably used.

The abrasive composition for CMP of the present invention may contain two or more kinds of the polyglycerin derivative (A) represented by the above formula (a).

The content of the polyglycerin derivative (A) in the polishing composition for CMP of the present invention (the total amount when two or more kinds are contained) is, for example, 0.5 with respect to 1 part by weight of the polishing agent (B). 10 to 10 parts by weight, preferably 0.5 to 8 parts by weight, particularly preferably 0.5 to 6 parts by weight, most preferably 0.5 to 3 parts by weight. The content of the polyglycerin derivative (A) is, for example, about 0.01 to 20% by weight, preferably 0.05 to 15% by weight, and more preferably 0.1 to 10% of the total amount of the polishing composition for CMP. %, particularly preferably 0.1 to 5% by weight.

When the content of the polyglycerin derivative (A) is less than the above range, the cohesiveness of the abrasive (B) cannot be relaxed, and the abrasive (B) aggregates to form secondary particles having a large particle size. Scratches tend to occur on the wafer surface when the wafer surface is polished using the CMP abrasive composition. On the other hand, when the polyglycerin derivative (A) is excessively contained, the viscosity of the polishing composition for CMP becomes too high, and it tends to be difficult to use it for polishing the wafer surface.

[Abrasive (B)]
As the abrasive (B), a known and commonly used abrasive can be used, but among them, at least one selected from silicon dioxide, aluminum oxide, cerium oxide, silicon nitride, and zirconium oxide can be used. Preference is given to using.

The silicon dioxide is not particularly limited and, for example, colloidal silica, fumed silica and the like can be used.

As aluminum oxide, α-alumina, δ-alumina, θ-alumina, κ-alumina, and other morphologically different ones can be used. Moreover, what is called fumed alumina from the manufacturing method can also be used.

As the cerium oxide, trivalent or tetravalent hexagonal cerium oxide, equiaxed cerium oxide, and face-centered cubic cerium oxide can be used.

As the silicon nitride, α-silicon nitride, β-silicon nitride, amorphous silicon nitride, and other morphologically different ones can be used.

As zirconium oxide, monoclinic zirconium oxide, tetragonal zirconium oxide, amorphous zirconium oxide and the like can be used. Moreover, what is called fumed zirconia from a manufacturing method can also be used.

The average particle diameter (by DLS method) of the primary particles of the abrasive (B) is, for example, 0.005 to 0.5 μm, preferably 0.01 to 0.3 μm, and particularly preferably 0.03 to 0.3 μm. .. If the average particle diameter of the primary particles of the abrasive (B) exceeds the above range, scratches are likely to occur on the surface of the object to be polished, and it tends to be difficult to flatten the surface of the object to be polished with high accuracy. There is. On the other hand, when the average particle size of the primary particles of the abrasive (B) is less than the above range, the polishing rate tends to be extremely slow.

In the present invention, it is preferable to use the abrasives (B) having different average particle sizes in combination, and the average particle size of the primary particles is, for example, 0.05 to 0.5 μm (preferably 0.1 to 0. 3 μm) abrasive (b-1) and the average particle size of primary particles is 0.005 or more and less than 0.05 μm (preferably 0.01 or more and less than 0.05 μm) (b-2) It is preferable to use a combination of (1) and (3) in combination with low scratch resistance and an appropriate polishing rate. When the abrasives (b-1) and the abrasives (b-2) are used in combination, the use ratio of these is such that the abrasives (b- 2) is about 0.1 to 10 parts by weight, preferably 0.3 to 5.0 parts by weight, particularly preferably 0.5 to 2.0 parts by weight.

The content of the abrasive (B) (the total amount when two or more kinds are contained) is, for example, about 0.1 to 50% by weight of the total amount of the abrasive composition for CMP, and the upper limit is preferably 40% by weight. %, more preferably 35% by weight, even more preferably 20% by weight, particularly preferably 10% by weight, most preferably 5% by weight. The lower limit is preferably 0.5% by weight, particularly preferably 1% by weight. When the polishing agent (B) is added to the CMP polishing agent composition in the above range, the viscosity can be adjusted within a range suitable for polishing, and both low scratch resistance and appropriate polishing rate can be provided.

[Water (C)]
The water (C) is not particularly limited and, for example, ultrapure water, ion-exchanged water, distilled water, tap water, industrial water and the like can be used. The content of water (C) can be appropriately adjusted, but is, for example, about 40 to 99 wt% of the total amount of the CMP abrasive composition. The lower limit of the content of water (C) is preferably 45% by weight, more preferably 55% by weight, particularly preferably 70% by weight, most preferably 80% by weight. By containing water in the above range, the viscosity of the polishing composition for CMP can be adjusted to a range suitable for polishing, and both low scratch resistance and appropriate polishing rate can be provided.

[Abrasive composition for CMP]
The abrasive composition for CMP of the present invention may contain other components in addition to the above components, if necessary. Examples of the other component include a rust inhibitor, a viscosity modifier, a surfactant other than the polyglycerin derivative (A), a chelating agent, a pH adjuster, an antiseptic, and an antifoaming agent. These may be contained alone or in combination of two or more. The content of the other components (the total amount when two or more types are contained) is, for example, about 40% by weight or less, preferably 0.001 to 10% by weight, more preferably 0. The amount is 05 to 5% by weight, and more preferably 0.01 to 2% by weight. Therefore, the ratio of the total content of the polyglycerin derivative (A), the abrasive (B) and the water (C) in the total amount of the CMP abrasive composition of the present invention is, for example, 60% by weight or more, preferably 80%. It is preferably at least 90% by weight, more preferably at least 90% by weight, particularly preferably at least 95% by weight, most preferably at least 98% by weight. The upper limit is 100% by weight.

The rust preventive agent is not particularly limited, and for example, the rust preventive agent described in Petroleum Product Additives (published on August 10, 1974, Kosho Shobo) can be used. For example, octylamine and the like can be used. Alkylamines such as alkylamines and oleylamines; cycloalkylamines such as cyclohexylamines; aliphatic or alicyclic amines having 2 to 16 carbon atoms; or ethylene oxides of the aliphatic or alicyclic amines having 2 to 16 carbon atoms ( 1 to 2 mol) adduct; an alkanolamine having 2 to 4 carbon atoms such as monoethanolamine, diethanolamine, and monopropanolamine, or an ethylene oxide (1 to 2 mol) adduct of the alkanolamine having 2 to 4 carbon atoms; Salts of aliphatic carboxylic acids having 18 to 20 carbon atoms such as oleic acid and stearic acid with alkali metals (Li, Na, K, Rb, Cs) or alkaline earth metals (Ca, Sr, Ba, Mg); petroleum Sulfonates such as sulfonates; phosphates such as lauryl phosphate; silicates such as sodium silicate and calcium silicate; phosphates such as sodium phosphate, potassium phosphate, sodium polyphosphate; sodium nitrite etc. Nitrite; benzotriazole and the like can be mentioned.

The content of the rust preventive agent (when two or more kinds are contained, the total amount thereof) is, for example, about 0.01 to 5% by weight, preferably 0.05 to 3% by weight, based on the total amount of the polishing composition for CMP. More preferably, it is 0.1 to 2% by weight.

In the present invention, the viscosity modifier is used for the purpose of diluting the abrasive composition for CMP, and examples thereof include monohydric water-soluble alcohols such as methanol, ethanol and propanol; ethylene glycol and propylene glycol. , Butylene glycol, glycerin, and dihydric or higher water-soluble alcohols such as polyethylene glycol having a degree of polymerization of 2 to 50.

The content of the above-mentioned viscosity modifier (when two or more kinds are contained, the total amount) is, for example, about 0.1 to 30% by weight, preferably 0.5 to 20% by weight, and more preferably about 0.5 to 20% by weight of the total amount of the CMP abrasive composition. It is preferably 1 to 10% by weight.

The surfactants other than the polyglycerin derivative (A) include nonionic surfactants other than the polyglycerin derivative (A), anionic surfactants, cationic surfactants, and amphoteric surfactants.

Examples of nonionic surfactants other than the polyglycerin derivative (A) include aliphatic alcohols (C8 to C24) alkylene oxides (alkylene C2 to C8) adducts (degree of polymerization 2 to 100); mono. Polyoxyalkylene (C2 to C8 of alkylene, degree of polymerization 2 to 100) higher fatty acid (C8 to C24) ester such as polyethylene glycol stearate (degree of polymerization 20), polyethylene glycol distearate (degree of polymerization 30); Glycerin monostearate, ethylene glycol monostearate, sorbitan monolaurate, sorbitan dioleate, and other polyhydric (2 to 10 valent or higher) alcohols (C2 to C10) higher fatty acids (C8 to C24) esters Polyoxyalkylenes such as polyoxyethylene monolaurate (degree of polymerization 10) sorbitan, polyoxyethylene (degree of polymerization 50) dioleic acid methyl glucoside (alkylene carbon number 2-8, degree of polymerization 2-100) polyvalent (2 Alcohol (having 2 to 10 carbon atoms) higher fatty acid (having 8 to 24 carbon atoms) ester; polyoxyalkylene (having 2 to 8 carbon atoms of alkylene, polymerization degree of 2 to 100) alkyl (having 1 to 22 carbon atoms) ) Phenyl ether; polyoxyalkylene (alkylene having 2 to 8 carbon atoms, degree of polymerization 1 to 100) alkyl (carbon number 8 to 24) amino ether; alkyl such as lauryl dimethylamine oxide (carbon number to 8 to 24) dialkyl (carbon 1 to 6) amine oxide and the like.

Examples of the anionic surfactant include polyoxyethylene (polymerization degree: 2 to 100), a hydrocarbon (ether)carboxylic acid having 8 to 24 carbon atoms such as sodium lauryl ether acetate, or a salt thereof; sodium lauryl sulfate, polyoxyethylene. (Polymerization degree 2 to 100) Sodium lauryl sulfate, polyoxyethylene (Polymerization degree 2 to 100) lauryl sulfate triethanolamine, polyoxyethylene (Polymerization degree 2 to 100) Coconut oil fatty acid monoethanolamide sodium sulfate, etc. 8 carbon atoms To 24 hydrocarbon (ether) sulfate ester salt; sodium dodecylbenzene sulfonate, polyoxyethylene (polymerization degree: 2 to 100) lauryl sulfosuccinic acid-2-sodium salt, etc., hydrocarbon (ether) sulfonate having 8 to 24 carbon atoms Salt; polyoxyethylene sulfosuccinate (polymerization degree: 2 to 100) lauroylethanolamide-2-sodium, coconut oil fatty acid methyl taurine sodium, coconut oil fatty acid sarcosine sodium, coconut oil fatty acid sarcosine triethanolamine, N-coconut oil fatty acid acyl- Examples include L-glutamic acid triethanolamine, N-coconut oil fatty acid acyl-L-glutamic acid sodium salt, and lauroylmethyl-β-alanine sodium salt.

Examples of the cationic surfactant include quaternary ammonium salt type cationic surfactants such as stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, distearyldimethylammonium chloride, and lanolin fatty acid aminopropylethyldimethylammonium ethylsulfate; stearin; Examples thereof include amine salt type cationic surfactants such as acid diethylaminoethylamide lactate, dilaurylamine hydrochloride and oleylamine lactate.

Examples of the amphoteric surfactant include coconut oil fatty acid amide propyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, laurylhydroxysulfobetaine, lauroylamide. Examples include betaine-type amphoteric surfactants such as ethyl hydroxyethyl carboxymethyl betaine hydroxypropyl; amino-acid type amphoteric surfactants such as sodium β-laurylaminopropionate.

The content of the surfactant other than the polyglycerin derivative (A) (the total amount when two or more kinds are contained) can be appropriately adjusted according to the application etc., but the total amount of the abrasive composition for CMP is For example, it is 5% by weight or less, preferably 3% by weight or less, particularly preferably 1% by weight or less, and most preferably less than 0.1% by weight.

Examples of the chelating agent include sodium polyacrylate, sodium ethylenediaminetetraacetate, sodium succinate, sodium 1-hydroxyethane-1,1-diphosphonate, and the like.

Examples of the pH adjuster include acids such as acetic acid, boric acid, citric acid, oxalic acid, phosphoric acid and hydrochloric acid; alkalis such as ammonia, sodium hydroxide and potassium hydroxide.

Examples of the preservative include alkyldiaminoethylglycine hydrochloride and the like.

Examples of the defoaming agent include silicone, long-chain alcohol having 4 to 16 carbon atoms, fatty acid ester having 4 to 16 carbon atoms, metal soap and the like.

The abrasive composition for CMP of the present invention can be produced by mixing the above components using a known and commonly used mixing device. When using an abrasive having poor dispersibility, a planetary mixer having a strong shearing force may be used. The order of mixing the raw materials is not particularly limited. When silicon dioxide is used as the abrasive (B), it is preferable to adjust the pH using a pH adjuster such as alkali, since a stable dispersed state can be obtained at a pH of 8 or higher. The thus obtained CMP abrasive composition of the present invention may be in the form of a slurry.

In the abrasive composition for CMP of the present invention, the polyglycerin derivative (A) interacts with the abrasive (B), whereby the agglomeration of the abrasive (B) can be mitigated, and the abrasive (B) can be reduced. Can be suppressed from forming secondary particles having a large average particle size. Therefore, when the polishing composition for CMP of the present invention is used for polishing the surface of a wafer or a substrate for a liquid crystal display, the surface of a wafer or a substrate for a liquid crystal display can be efficiently and smoothly polished. It is possible to suppress the occurrence of scratches on the surface of the substrate for use. In addition, since the polyglycerin derivative (A) has excellent solubility in water and the organic solvent described later, after polishing, it is washed with water and further washed with an organic solvent, so that the surface of the wafer or the substrate for the liquid crystal display is polished with an abrasive or polished. Debris can be easily removed.

Examples of the organic solvent that can be used for washing include methanol, ethanol, 2-propanol, 1-butanol, 2-ethoxymethanol, 1-methoxy-2-propanol, 3-methoxy-1-propanol, 1-methoxy-2. -Alcohol solvents such as propanol; ketone solvents such as acetone, acetylacetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptanone, 3-heptanone, cyclopentanone, cyclohexanone; ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, acetic acid Ester solvents such as pentyl, ethyl propionate, propyl propionate, butyl propionate, isobutyl propionate, 1-methoxy-2-propylacetate, methyl lactate, ethyl lactate, γ-butyrolactone; diisopropyl ether, dibutyl ether, Ether solvents such as ethyl propyl ether, anisole, phenetole, veratrol; aromatic hydrocarbon solvents such as mesitylene, ethylbenzene, diethylbenzene, propylbenzene, t-butylbenzene; amide solvents such as N-methylpyrrolidone, dimethylacetamide, etc. Can be mentioned. These can be used individually by 1 type or in combination of 2 or more types. In the present invention, among others, an ester solvent can be preferably used in view of the solubility of the polyglycerin derivative (A).

[Semiconductor Device Manufacturing Method]
The method for manufacturing a semiconductor device of the present invention includes the step of polishing the surface irregularities of a wafer to planarize it using the above-described CMP abrasive composition.

As the wafer, for example, a silicon wafer, gallium arsenide wafer, germanium wafer, sapphire wafer, gallium phosphide wafer, gallium arsenide wafer, indium phosphide wafer, gallium nitride wafer, or the like can be used.

The polishing machine used in the method for manufacturing a semiconductor device of the present invention is not particularly limited and, for example, a rotary type, a belt type or the like can be used. An example of a typical polishing machine is shown in FIG. As a polishing method using a polishing machine, for example, the surface plate (1) and the polishing head (5) are rotated, and the CMP abrasive composition (4) is supplied from the CMP abrasive composition supply pipe (3). A method of polishing by pressing the surface of the wafer (6) against the surface of the polishing pad (2) provided on the surface plate (1) while supplying it near the polishing head (5) can be mentioned.

The supply amount of the abrasive composition for CMP (4) is about 50 to 1000 mL/min. The number of rotations of the polishing head (5) and the surface plate (2) is about 10 to 100 rpm.

As the polishing pad (2), an ordinary foam such as polyurethane resin can be preferably used.

Polishing is preferably performed at room temperature (1 to 30° C.) under a pressure of 1 to 10 psi (about 6.90 to 69.0 kPa). The polishing time is about 10 seconds to 5 minutes.

After the polishing is completed, it is preferable to wash the surface of the wafer with water and further wash with the above-mentioned organic solvent. Since the polishing composition for CMP is used in the present invention, polishing debris, abrasives, additives, etc. can be promptly removed by washing with water and an organic solvent, and the polishing debris remains. Can be suppressed. Either washing with water or washing with an organic solvent may be performed first.

According to the method for manufacturing a semiconductor device of the present invention, the wafer surface can be flattened with high accuracy without generating scratches, and the wirings of elements such as transistors are stacked as designed to form a multilayer wiring layer. can do. Further, the presence of irregularities on the surface causes disconnection of wiring, local increase in resistance value, and the like, resulting in disconnection and reduction in current capacity. However, according to the method for manufacturing a semiconductor device of the present invention, reliability is improved. It is possible to provide a semiconductor device having high cost.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

The materials used in Examples and Comparative Examples are as follows.
<Surfactant>
-Polyglycerin derivative (A-1): A product obtained by adding 19 mol of 2-ethylhexyl glycidyl ether to 1 mol of glycerin, weight average molecular weight: 3800, and the product produced according to Preparation Example 1 were used-Polyglycerin derivative (A-2): 10 mol of 2-ethylhexyl glycidyl ether was added to 1 mol of decaglycerin, weight average molecular weight: 2700, and the product produced in Preparation Example 2 was used. Polyglycerin derivative (A-3): poly(20) glycerin 1 mol and lauric acid The thing which added 10 mol, the weight average molecular weight:3500, and what was manufactured by the preparation example 3 was used.-Polyglycerin derivative (A-4): Poly(20) glycerol 1 mol added with 10 mol of isostearic acid, weight average molecular weight : 4200, the one prepared in Preparation Example 4 was used.-Polyglycerin derivative (PG-1): 1 mol of lauryl alcohol to which 4 mol of 2,3-epoxy-1-propanol was added, weight average molecular weight: 480, trade name "PGLAL ML04", manufactured by Daicel Corp., polyglycerin derivative (PG-2): 10 mol of 2,3-epoxy-1-propanol added to 1 mol of lauryl alcohol, weight average molecular weight: 927
-Polyglycerin derivative (PG-3): 6 mol of 2,3-epoxy-1-propanol added to 1 mol of lauryl alcohol, weight average molecular weight: 630
Polyglycerin derivative (PG-4): 1 mol of isostearyl alcohol to which 10 mol of 2,3-epoxy-1-propanol is added, weight average molecular weight: 1020
-Polyglycerin derivative (PG-5): 2,3-epoxy-1-propanol 9 mol added to 1 mol of glycerin, weight average molecular weight: 760, trade name "PGL 10PS", manufactured by Daicel Corporation-Polyglycerin derivative (PG-6): 19 mol of 2,3-epoxy-1-propanol added to 1 mol of glycerin, weight average molecular weight: 1500, trade name "PGL 20P", manufactured by Daicel Corporation, polyoxyalkylene derivative (POA- 1): 48 mol of ethylene oxide added to 1 mol of ethylene glycol, and 38 mol of propylene oxide added thereto, weight average molecular weight: 4,400
Polyoxyalkylene derivative (POA-2): 32 mol of ethylene oxide added to 1 mol of ethylene glycol and then 20 mol of propylene oxide, weight average molecular weight: 2600
-Polyoxyalkylene derivative (POA-3): 10 mol of ethylene oxide added to 1 mol of lauryl alcohol, weight average molecular weight: 630, trade name "EMALEX 710", manufactured by Nippon Emulsion Co., Ltd.-Polyoxyalkylene derivative (POA-4) ): 20 mol of ethylene oxide added to 1 mol of lauryl alcohol, weight average molecular weight: 1100, trade name "EMALEX 720", manufactured by Nippon Emulsion Co., Ltd.

Preparation Example 1 (Preparation of polyglycerin derivative (A-1))
90 parts by weight of glycerin and 48% NaOH aqueous solution as an alkali catalyst were charged into a reaction vessel, and 3540 parts by weight of 2-ethylhexyl glycidyl ether (amount of 19 mol with respect to 1 mol of glycerin) was maintained at 100° C. After dripping over a period of time and aging for 1 hour, an 85% phosphoric acid aqueous solution was added to stop the reaction, and an adduct was obtained.

Preparation Example 2 (Preparation of polyglycerin derivative (A-2))
An adduct was obtained in the same manner as in Preparation Example 1 except that decaglycerin was used instead of glycerin, and the amount of 2-ethylhexylglycidyl ether used was changed to 10 mol with respect to 1 mol of decaglycerin.

Preparation Example 3 (Preparation of polyglycerin derivative (A-3))
1500 parts by weight of poly(20)glycerin, 2000 parts by weight of lauric acid (amount of 10 mol based on 1 mol of poly(20)glycerin), and 48% aqueous sodium hydroxide solution were charged into a reaction vessel. Under a nitrogen stream, the internal temperature was raised to 200° C. under normal pressure, and the reaction was performed for 10 hours. After completion of the reaction, it was cooled to room temperature to obtain an adduct.

Preparation Example 4 (Preparation of polyglycerin derivative (A-4))
An adduct was obtained in the same manner as in Preparation Example 3 except that isostearic acid was used instead of lauric acid.

Preparation Example 5 (Preparation of abrasive slurry)
10 parts by weight of colloidal silica (average particle size of primary particles: 0.035 μm) and 10 parts by weight of cerium oxide (average particle size of primary particles: 0.2 μm) were mixed with a stirrer (trade name “TK homomixer”, Primex). (Manufactured by Co., Ltd.) was used to disperse in water to prepare an abrasive slurry with an abrasive concentration of 20% by weight.

Example 1
As a surfactant, 4.0 parts by weight of the polyglycerin derivative (A-1) obtained in Preparation Example 1, 20 parts by weight of the abrasive slurry obtained in Preparation Example 5, 0.2 parts by weight of aqueous ammonia as a pH adjuster , And ion-exchanged water (200 mL) were mixed by using a stirrer (trade name “TK homomixer”, manufactured by PRIMIX Corporation) to obtain a composition 1 (pH: 8.3).

Examples 2-4, Comparative Examples 1-10
A composition was obtained in the same manner as in Example 1 except that the formulation shown in Table 1 below was changed.

[Evaluation test]
The compositions 1 to 14 obtained in Examples and Comparative Examples were evaluated for low scratch resistance, dispersibility test, and detergency by the following methods.
[Low scratch test]
As the object to be polished, a silicon wafer having a diameter of 8 inches having a silicon oxide film formed on the surface by thermal oxidation to have a thickness of 1 μm was used. The polishing machine used was a single-sided polishing machine (trade name "EPO113", manufactured by EBARA CORPORATION), and the polishing pad used was trade name "IC1000" (manufactured by Rodel).
Polishing conditions Processing pressure: 5 psi
Plate rotation speed: 60 rpm
Wafer rotation speed: 50 rpm
Composition supply rate: 150 mL/min Polishing time: 2 minutes

After polishing the silicon wafer under the above polishing conditions, after the polishing is finished, the silicon wafer is washed with pure water and dried, and a scratch (scratch) having a length of 0.2 μm or more on the surface of the silicon wafer due to polishing is observed. The low scratch resistance was evaluated. The product name "Surfscan SP-1" (produced by KLA-Tencor) was used for the scratch observation.
Low Scratch Evaluation Criteria Less than 5 scratches: Very good (◎)
The number of scratches is 5 or more and less than 20: Good (○)
The number of scratches is 20 or more and less than 30: Somewhat bad (△)
30 or more scratches: bad (x)

[Dispersibility test]
After completion of polishing, 1 L of the recovered composition was filtered using a membrane filter (diameter: 47 mm) having a pore size of 1 μm at a primary pressure (stock solution side of the filter: p ¹ ) of 2 kg/cm ² and a secondary side. The pressure (filtrate side of the filter: p ² ) was measured, the pressure loss was calculated by the following formula, and the dispersibility was evaluated according to the following criteria. For the pressure measurement, a product name “Manostar gauge WO81FN100” (manufactured by Yamamoto Electric Co., Ltd.) was used.
Pressure loss (%)={(p ¹ −p ² )/p ¹ }×100
Dispersibility evaluation criteria Less than 10%: Very good (◎)
10% or more and less than 50%: good (○)
50% or more and less than 70%: Somewhat bad (△)
70% or more, or clogging on the way and filtration is impossible: bad (x)

[Cleanability test]
After polishing, 1 g of the recovered composition was mixed with 7 g of methoxypropanol and 3 g of 1-methoxy-2-propylacetate under the condition of 25° C., and the appearance was visually observed. The washability was evaluated by.
Detergency evaluation criteria Dissolution: Very good (◎)
White turbid dispersion: Good (○)
Complete separation: Bad (x)

The evaluation results are summarized in Table 2 below.

From the results of evaluation of low scratch resistance and dispersibility in Table 2, the compositions 1 to 4 containing the polyglycerin derivative (A) as the surfactant have excellent dispersibility, and the pressure loss due to passing through the membrane filter is 50%. Could be suppressed to less than. Then, when the surface of the silicon wafer was polished using the compositions 1 to 4, the occurrence of scratches could be suppressed to an extremely low level.
On the other hand, the compositions 11 to 14 using the polyoxyalkylene derivative instead of the polyglycerin derivative (A) cannot suppress the aggregation of the abrasive (B), and the average particle diameter of the secondary particles of the abrasive (B). As a result, the pressure loss due to passing through the membrane filter was 50% or more. When using the compositions 11 to 14, 20 or more scratches were generated.

Moreover, from the above-mentioned detergency evaluation results, the compositions 1 to 4 containing the polyglycerin derivative (A) as a surfactant have excellent dispersibility/solubility in an organic solvent, while the polyglycerin derivative (A) was used instead of the polyglycerin derivative (A). The compositions 5 to 10 using the glycerin derivative (PG) were neither dispersed nor dissolved in the organic solvent.

From the above results, the abrasive composition for CMP of the present invention can prevent the abrasive (B) from aggregating with the polyglycerin derivative (A) and can keep the average particle size small, and It can be seen that the occurrence of scratches caused can be suppressed. Further, it is understood that the CMP abrasive composition of the present invention has excellent cleaning properties, and the abrasive and polishing debris can be removed cleanly by cleaning with an organic solvent after polishing.

1 Surface Plate 2 Polishing Pad 3 CMP Abrasive Composition Supply Pipe 4 CMP Abrasive Composition 5 Polishing Head 6 Wafer

Claims (5)

Formula (a) below
_{RO- (C 3 H 5 O 2} R) n -R (a)
(In the formula, repeating units shown in parentheses are represented by the following formula (1) and/or (2)

It is represented by. R is the same or different and represents a hydrogen atom, a hydrocarbon group having 1 to 18 carbon atoms, or an acyl group having 2 to 24 carbon atoms. However, among (n+2) R, at least 2 is a hydrocarbon group having 1 to 18 carbon atoms and/or an acyl group having 2 to 24 carbon atoms. n represents the number of the repeating unit and is an integer of 2 to 60)
An abrasive composition for chemical mechanical polishing, which comprises the polyglycerol derivative (A) represented by the formula (A), the abrasive (B), and water (C). The polyglycerin derivative (A) is represented by the formula (a), and 25 to 95% of (n+2) Rs in the formula (a) are hydrocarbon groups having 1 to 18 carbon atoms and/or 2 carbon atoms. The chemical-mechanical polishing abrasive composition according to claim 1, which is a compound having an acyl group of -24. The abrasive composition for chemical mechanical polishing according to claim 1 or 2, wherein the content of the polyglycerin derivative (A) is 0.5 to 10 parts by weight with respect to 1 part by weight of the abrasive (B). .. The abrasive (B) is at least one compound selected from the group consisting of silicon dioxide, aluminum oxide, cerium oxide, silicon nitride, and zirconium oxide. Abrasive composition for chemical mechanical polishing. A method for manufacturing a semiconductor device, comprising a step of polishing a wafer using the chemical composition polishing chemical composition according to claim 1.

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