JP2009012159A - Aqueous dispersing element for chemical mechanical polishing used for manufacturing multilayer circuit board, method for polishing substrate and multilayer circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous dispersing element for chemical mechanical polishing uniformly and stably polishing a metal film by low friction, while making a high polishing speed and a high flattening characteristic compatible without causing defects in metal film and insulation film, and polishing a wiring layer made of copper and copper alloy provided in an organic resin insulating substrate having little Cu remainder after polishing and excellent polishing selectivity of a Cu film. <P>SOLUTION: This aqueous dispersing element for chemical mechanical polishing polishes the wiring layer containing copper or copper alloy provided in the organic resin insulating substrate. The organic resin insulating substrate contains one or more kinds of compounds selected among (A) organic acid, (B) surface-active agent, (C) oxidant, (D) abrasive grains and (E) ammonia and ammonium salt, and has the total concentration of (A) component and (E) component of 1 to 15 wt.% in relation to the total weight of the aqueous dispersing element, and a ratio of concentration of the (C) component and the total concentration of (A) component and (E) component is 1:1 to 1:50. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an aqueous dispersion for chemical mechanical polishing useful for polishing for wiring formation in the production of a multilayer circuit board, a method for producing a multilayer circuit board using the aqueous dispersion, and a multilayer circuit board.

In recent years, with the miniaturization of semiconductors, miniaturization and multilayering of printed circuit boards have been demanded. Accordingly, the unevenness of the substrate surface caused by the variation in the thickness of the inner layer wiring pattern tends to increase. In particular, when the wiring pattern is formed by electrolytic copper plating, the thinner the wiring pattern, the thicker the plating thickness, and the plating thickness is uneven due to the difference in current distribution during plating due to the density of the wiring density. become. For this reason, there is a problem that the variation in the plating thickness of the wiring pattern formed by electrolytic copper plating increases as the miniaturization progresses. Insufficient connection between the layers due to the unevenness of each wiring layer, and also when mounting an IC chip on a multilayer circuit board, the connection with the IC chip is likely to occur due to the unevenness of the substrate surface. In order to solve this problem, for example, as described in Patent Document 1, each wiring layer is flattened by roll buffing.

However, conventional roll buff polishing is a method in which a roll buff formed in a cylindrical shape by bonding hard abrasive grains with a binder is rolled on the surface of the copper layer, and it is difficult to obtain sufficient flatness. In addition, there was a problem in that scratches occurred and the electrical characteristics also deteriorated. In addition, in such buffing, for example, as described in Patent Document 2, studies using a slurry have been conducted, but what is a technical level that requires high surface smoothness such as a multilayer wiring board? It's hard to say.
JP 2002-134920 A JP2003-257910A

  The present invention can uniformly and stably polish a metal film with low friction without causing defects in a metal film or an insulating film, while achieving both a high polishing rate and a high planarization characteristic. Provided is a chemical mechanical polishing aqueous dispersion for polishing a wiring layer made of copper or a copper alloy provided on an organic resin insulating substrate with little remaining and excellent Cu film polishing selectivity. It is another object of the present invention to provide a method for producing a multilayer circuit board using the chemical mechanical polishing aqueous dispersion of the present invention.

  The present inventors include (A) an organic acid, (B) a surfactant, (C) an oxidizing agent, (D) an abrasive, (E) one or more compounds selected from ammonia and an ammonium salt, The total concentration of the component (A) and the component (E) is 1 to 15% by weight with respect to the total weight of the aqueous dispersion, and the concentration of the component (C) and the sum of the components (A) and (E) Using the chemical mechanical polishing aqueous dispersion for polishing a wiring layer containing copper or a copper alloy provided on an organic resin insulating substrate, the ratio of which is 1: 1 to 1:50. I found that it can be solved.

  The method for producing a multilayer circuit board according to the present invention is characterized by performing chemical mechanical polishing using the chemical mechanical polishing aqueous dispersion.

  According to the present invention, a metal film can be uniformly and stably polished with low friction while achieving both a high polishing rate and high planarization characteristics without causing defects in the metal film and the insulating film. There is provided an aqueous dispersion for chemical mechanical polishing for polishing a wiring layer made of copper or a copper alloy provided on an organic resin insulating substrate having little Cu residue and excellent Cu film polishing selectivity. Also provided is a method for producing a multilayer circuit board using the chemical mechanical polishing aqueous dispersion of the present invention.

[Chemical mechanical aqueous dispersion]
The chemical mechanical polishing aqueous dispersion according to the present invention is one type selected from (A) an organic acid, (B) a surfactant, (C) an oxidizing agent, (D) abrasive grains, (E) ammonia and an ammonium salt. The total concentration of the component (A) and the component (E) is 1 to 15% by weight with respect to the total weight of the aqueous dispersion, and the concentration of the component (C) and (A) The ratio of the component and the total concentration of the component (E) is 1: 1 to 1:50. Hereinafter, each component will be described in detail.

<(A) Organic acid>
The organic acid (A) used in the present invention is preferably an organic acid having a coordination ability with respect to the surface of the wiring material containing ions or copper or copper alloy comprising the wiring material element. More preferably, an organic acid having chelate coordination ability is preferred. By adding an organic acid having coordination ability to the surface of the wiring material containing such copper or copper alloy, the polishing rate of the wiring material can be accelerated.

  Examples of the organic acid (A) used in the present invention include tartaric acid, fumaric acid, glycolic acid, phthalic acid, maleic acid, oxalic acid, citric acid, malic acid, malonic acid, glutaric acid, quinolinic acid, quinaldic acid and the like. And organic acids such as glycine, alanine, aspartic acid, glutamic acid, lysine and arginine, and amino acids such as aromatic amino acids, heterocyclic amino acids and tryptophan can be preferably used. It is particularly preferable to use glycine.

  The content of the organic acid (A) used in the present invention is preferably 0.05 to 12% by weight, more preferably 0.5 to 10% by weight, particularly 1 to 8% by weight, based on the total amount of the aqueous dispersion. Is preferred. (A) If the content of the organic acid is less than 0.05% by weight, the desired polishing rate cannot be achieved, and it takes a long time to complete the polishing. Further, when the organic acid (A) exceeds 12% by weight, the chemical etching effect is increased, and the flatness is deteriorated and the wiring layer is corroded.

  The organic acid (A) used in the present invention may be dissociated in the aqueous dispersion. In that case, the dissociation part in the case of a divalent or higher acid may be monovalent or higher. Moreover, the cation of the pair of dissociation part may be any of hydrogen ions and other cations derived from additives that are optionally added, such as ammonium ions and potassium ions.

  The total concentration of the component (A) and the component (E) used in the present invention is preferably 1 to 15% by weight, more preferably 2 to 12% by weight, based on the total weight of the aqueous dispersion. More preferably, it is 3 to 10% by weight. If the total concentration of the component (A) and the component (E) is less than the above range, the polishing rate tends to decrease due to a decrease in the etching property to the wiring material. Corrosion may occur, which is not preferable.

<(B) Surfactant>
As the surfactant (B) used in the present invention, a nonionic surfactant, an anionic surfactant or a cationic surfactant can be used. As said nonionic surfactant, the nonionic surfactant which has a triple bond is mentioned, for example. Specifically, acetylene glycol and its ethylene oxide adduct, acetylene alcohol, etc. are mentioned. Also included are silicone surfactants, polyvinyl alcohol, cyclodextrin, polyvinyl methyl ether, and hydroxyethyl cellulose. Examples of the cationic surfactant include aliphatic amine salts and aliphatic ammonium salts. Examples of the anionic surfactant include aliphatic soap, sulfate ester salt, and phosphate ester salt.

  The (B) surfactant used in the present invention is preferably an anionic surfactant. As the anionic surfactant, for example, sulfonates such as alkylbenzene sulfonate, alkylnaphthalene sulfonate, and α-olefin sulfonate can be used. In particular, it is preferable to use sulfonates such as potassium dodecylbenzenesulfonate and ammonium dodecylbenzenesulfonate. These surfactants can be used singly or in combination of two or more.

  The content of the (B) surfactant used in the present invention is preferably 0.005 to 1.0% by weight, more preferably 0.01 to 0.5% by weight, particularly with respect to the total amount of the aqueous dispersion. 0.02 to 0.15% by weight is preferred. (B) If the content of the surfactant is less than 0.005% by weight, the flatness may deteriorate or the polishing performance in the substrate surface may not be stabilized. In addition, when the surfactant content is added in excess of 1.0% by weight, the flatness improving effect on the content is reduced, and the aqueous dispersion is liable to foam, so that the handleability is deteriorated. Absent.

<(C) Oxidizing agent>
Examples of the (C) oxidizing agent used in the present invention include hydrogen peroxide, peracetic acid, perbenzoic acid, organic peroxides such as tert-butyl hydroperoxide, permanganate compounds such as potassium permanganate, Dichromic acid compounds such as potassium dichromate, halogen acid compounds such as potassium iodate, nitric acid compounds such as nitric acid and iron nitrate, perhalogenated compounds such as perchloric acid, persulfates such as ammonium persulfate, and heteropolyacids Etc.
Of these oxidants, hydrogen peroxide, organic peroxides, or persulfates such as ammonium persulfate are preferred in view of oxidizing power, corrosiveness to organic resin substrates, and ease of handling. Is preferred. By containing these oxidizing agents, the polishing rate can be greatly improved.

  The content of the oxidizing agent (C) used in the present invention is preferably 0.05 to 5% by weight, more preferably 0.1 to 3% by weight, and particularly preferably 0.2 to 3% by weight with respect to the total amount of the aqueous dispersion. 2% by weight is more preferred. (C) When the content of the oxidizing agent is less than 0.05% by weight, the effect of chemical etching cannot be obtained sufficiently, which may cause a problem in the polishing rate. If contained, the surface to be polished may corrode.

  The ratio of the concentration of the component (C) used in the present invention to the total concentration of the component (A) and the component (E) is preferably 1: 1 to 1:50, more preferably 1: 2 to 1:30, more preferably 1: 3 to 1:15. If the ratio of the concentration of the component (C) used in the present invention and the total concentration of the components (A) and (E) is out of the above range, the polishing rate tends to decrease, which is not preferable.

<(D) Abrasive grain>
As the abrasive grains (D) used in the present invention, any one or more selected from silica particles, organic polymer particles, organic-inorganic composite particles, calcium carbonate particles, and the like can be used.

The silica particles include fumed silica synthesized by the fumed method in which silicon chloride and the like are reacted with oxygen and hydrogen in the gas phase, silica synthesized by the sol-gel method synthesized by hydrolytic condensation from metal alkoxide, and purification. And colloidal silica synthesized by an inorganic colloid method or the like from which impurities have been removed. In particular, colloidal silica synthesized by an inorganic colloid method in which impurities are removed by purification is preferred.
As the silica as the abrasive grain (D) used in the present invention, it is preferable to use colloidal silica having an average particle diameter of 200 nm or less because the flatness becomes good.

  Examples of the organic polymer particles include polyvinyl chloride, polystyrene and styrene copolymers, polyacetal, saturated polyester, polyamide, polycarbonate, polyethylene, polypropylene, poly-1-butene, and poly-4-methyl-1-pentene. In addition, (meth) acrylic resins such as olefin copolymers, phenoxy resins, and polymethyl methacrylate, acrylic copolymers, and the like can be used.

  The organic-inorganic composite particles are not particularly limited in type, configuration, etc. as long as the organic particles and the inorganic particles are integrally formed to such an extent that they are not easily separated during polishing. For example, polycondensation of alkoxysilane, aluminum alkoxide, titanium alkoxide, etc. in the presence of polymer particles such as polystyrene and polymethyl methacrylate, and polycondensation of polysiloxane, polyaluminoxane, polytitanoxane, etc. on at least the surface of the polymer particles The composite particle in which the thing was formed is mentioned. The formed polycondensate may be directly bonded to the functional group of the polymer particles, or may be bonded via a silane coupling agent or the like.

  The organic / inorganic composite particles may be formed using the polymer particles and silica particles, alumina particles, titania particles, or the like. In this case, the composite particles may be formed such that silica particles or the like are present on the surface of the polymer particles using a polycondensate such as polysiloxane, polyaluminoxane, or polytitanoxane as a binder. The functional group such as a hydroxyl group may be chemically bonded to the functional group of the polymer particle.

  Further, silica particles, alumina particles, or the like can be used instead of alkoxysilane or the like. These may be held in entanglement with polysiloxane or the like, or may be chemically bonded to the polymer particles by a functional group such as a hydroxyl group which they have.

  Furthermore, as the organic-inorganic composite particles, composite particles in which organic particles and inorganic particles having different signs of zeta potential are combined by an electrostatic force in an aqueous dispersion containing these particles may be used.

  The zeta potential of organic particles is often negative over the entire pH range or a wide pH range excluding a low pH range. In many cases, the organic particles have a negative zeta potential more reliably when they have a carboxyl group, a sulfonic acid group, or the like. When the organic particle has an amino group or the like, it may have a positive zeta potential in a specific pH range.

On the other hand, the zeta potential of inorganic particles is highly pH-dependent and has an isoelectric point at which the zeta potential is 0, and the sign of the zeta potential is reversed before and after the pH depending on the pH.
Therefore, by mixing specific organic particles and inorganic particles in a pH range in which the zeta potential has an opposite sign, the organic particles and the inorganic particles are combined by electrostatic force to form a composite particle. be able to. In addition, even if the zeta potential has the same sign at the pH at the time of mixing, the pH is changed thereafter, and the zeta potential of one particle, especially the inorganic particle, is reversed, thereby integrating the organic particles and the inorganic particles. It can also be converted.

  In this way, the composite particles integrated by electrostatic force are polycondensed with alkoxysilane, aluminum alkoxide, titanium alkoxide, etc. in the presence of the composite particles, so that at least the surface thereof has polysiloxane, polyaluminoxane, polytitanoxane. A polycondensate such as the above may be further formed.

  The calcium carbonate particles are preferably high-purity calcium carbonate particles obtained by reacting carbon dioxide after purifying calcium hydroxide in water.

  The average particle diameter of the (D) abrasive grains used in the present invention is preferably 40 to 500 nm. This average particle diameter can be measured by a laser scattering diffraction measuring instrument or by observation with a transmission electron microscope. When the average particle size is 40 nm or less, a chemical mechanical polishing aqueous dispersion having a sufficiently high polishing rate may not be obtained. If it exceeds 500 nm, a stable aqueous dispersion may not be easily obtained due to sedimentation and separation of the abrasive grains. The average particle diameter of the abrasive grains may be in the above range, but is more preferably 50 to 400 nm, and particularly preferably 60 to 300 nm. When the average particle diameter is in this range, a stable chemical mechanical polishing aqueous dispersion can be obtained in which the polishing rate is high, dishing and dishing are sufficiently suppressed, and precipitation and separation of particles are unlikely to occur.

  The content of the abrasive grain (D) used in the present invention is preferably 0.1 to 15% by weight, more preferably 0.2 to 5% by weight, based on the total amount of the aqueous dispersion. When the amount of abrasive grains is less than 0.1% by weight, a sufficient polishing rate may not be obtained, and when it exceeds 15% by weight, the cost increases and a stable chemical mechanical polishing aqueous dispersion cannot be obtained. There is.

<(E) One or more compounds selected from ammonia and ammonium salts>
Examples of one or more compounds selected from (E) ammonia and ammonium salts used in the present invention include, for example, ammonium sulfate, ammonium chloride, ammonium nitrate, monoammonium phosphate, diammonium phosphate, and organic acid ammonium. Mention may be made of ammonium formate, ammonium acetate, ammonium propionate, ammonium butyrate, ammonium lactate, ammonium succinate, ammonium malonate, ammonium maleate, ammonium fumarate, ammonium quinaldate and ammonium quinolinate. In particular, ammonium sulfate is preferable. Further, it is more preferable to use ammonia and ammonium sulfate in combination.

  The content of one or more compounds selected from (E) ammonia and ammonium salts is preferably 0.05 to 10.0% by weight based on the total amount of the chemical mechanical polishing aqueous dispersion, and is further 0 0.1 to 5.0% by weight is preferable, and 0.2 to 3.0% by weight is more preferable. (E) When the content of ammonia and ammonia salt is less than 0.05% by weight, it is difficult to achieve a sufficient polishing rate. On the other hand, if the content of one or more compounds selected from (E) ammonia and an ammonium salt is added in excess of 10.0% by weight, the flatness deteriorates.

<(F) Water-soluble polymer compound>
Examples of the water-soluble polymer compound (F) used in the present invention include polyvinylpyrrolidone (PVP), polyacrylic acid (PAA), polymethacrylic acid, a copolymer of acrylic acid and methacrylic acid, and polymaleic acid. Carboxylic acid-containing polymers and salts thereof, sulfonic acid-containing polymers such as polyisoprene sulfonic acid and salts thereof, and hydroxyl-containing polymers such as hydroxyethyl acrylate and polyvinyl alcohol can be suitably used.

  The content of the water-soluble polymer compound (F) used in the present invention is preferably 0.001 to 0.5% by weight, more preferably 0.005 to 0.3% by weight, based on the total amount of the aqueous dispersion. 0.01 to 0.2% by weight is particularly preferable. (F) When the content of the water-soluble polymer compound is less than 0.001% by weight, polishing friction may not be reduced, and the effect is difficult to obtain. Also, the polishing rate may decrease. On the other hand, if the content of (F) the water-soluble polymer compound exceeds 0.5% by weight, the polishing rate of Cu may be lowered. In addition, the viscosity of the chemical mechanical polishing aqueous dispersion may be too high to stably supply the slurry onto the polishing cloth. As a result, an increase in the temperature of the polishing cloth, uneven polishing (deterioration of in-plane uniformity), and the like may occur, resulting in variations in Cu polishing rate and Cu dishing.

  When the water-soluble polymer compound (F) used in the present invention is PVP, the value measured by polyethylene glycol equivalent weight average molecular weight (Mw) measured by aqueous GPC (gel permeation chromatography) is 200,000. It is preferable to use more PVP. Preferably, more than 200,000 and less than 1.5 million, more preferably 300,000 to 1,500,000, still more preferably 500,000 to 1,200,000, particularly preferably 650,000 to 1,100,000 PVP is used. When the weight average molecular weight of PVP is in the above range, friction during polishing can be reduced, and a wiring layer containing copper and copper can be stably polished. Moreover, dishing and corrosion of the wiring layer containing copper and copper can be suppressed. If the weight average molecular weight is smaller than the above lower limit, the above effect tends to be insufficient, which is not preferable. On the other hand, if the weight average molecular weight is too large, the polishing rate tends to decrease and the agglomeration of the abrasive grains tends to occur.

  When the water-soluble polymer compound (F) used in the present invention is PVP, the P value of PVP is preferably more than 57, more preferably more than 57 and not more than 106, more preferably not more than 106, Preferably it is 65-106, Most preferably, it is 76-100, Most preferably, it is 82-97. If the K value is out of the above range, the polishing rate may decrease, which is not preferable.

<Other ingredients>
The chemical mechanical polishing aqueous dispersion of the present invention includes various components such as acids, alkalis, anticorrosives for wiring materials, antifoaming agents and antifoaming agents that reduce foaming of the slurry as necessary, in addition to the above components. Additives can be blended. By these additives, the flatness can be improved and corrosion can be suppressed by adjusting the polishing rate and protecting the wiring surface, and the dispersion stability of the abrasive grains in the aqueous dispersion can be improved.

  For example, as the acid, inorganic acids such as nitric acid, sulfuric acid and phosphoric acid can be used in the chemical mechanical polishing aqueous dispersion of the present invention. For example, as the alkali, alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, rubidium hydroxide, and cesium hydroxide, organic alkali compounds such as TMAH, choline, and the like can be used. The pH of the aqueous dispersion can be adjusted by adjusting the blending amount of the acid and alkali. The polishing rate can be increased by adjusting the pH, within the range where the abrasive grains can exist stably, taking into consideration the electrochemical properties of the work surface, the dispersibility and stability of the abrasive grains, and the polishing speed. It is preferable to set the pH appropriately.

<Physical properties of aqueous dispersion for chemical mechanical polishing>
The chemical mechanical polishing aqueous dispersion of the present invention is an aqueous dispersion in which the above components are dispersed in water, and the viscosity thereof is preferably less than 2 mPa · s. If the viscosity of the chemical mechanical polishing aqueous dispersion exceeds the above range, the slurry may not be stably supplied onto the polishing cloth. As a result, an increase in the temperature of the polishing cloth, uneven polishing (deterioration of in-plane uniformity), and the like may occur, and variations may occur in the Cu polishing rate and Cu dishing.

<Method for preparing chemical mechanical polishing aqueous dispersion>
In the present invention, water contains at least one compound selected from (A) an organic acid, (B) a surfactant, (C) an oxidizing agent, (D) abrasive grains, and (E) ammonia and an ammonium salt, If necessary, other additives may be added and mixed as appropriate to prepare an aqueous dispersion for chemical mechanical polishing, which may be used as it is for chemical mechanical polishing, but the chemical mechanical polishing water containing each component in a high concentration. A system dispersion, that is, a concentrated aqueous dispersion, may be prepared and diluted to a desired concentration at the time of use to be used for chemical mechanical polishing.

  In addition, as described below, a plurality of liquids (for example, two or three liquids) containing any of the above components can be prepared, and these can be mixed and used at the time of use. In this case, after preparing a chemical mechanical polishing aqueous dispersion by mixing a plurality of liquids, this may be supplied to the chemical mechanical polishing apparatus, or a plurality of liquids may be supplied individually to the chemical mechanical polishing apparatus. A chemical mechanical polishing aqueous dispersion may be formed on a surface plate.

  The chemical mechanical polishing aqueous dispersion of the present invention can be supplied as a combination of at least (D) a composition (a) containing abrasive grains and a composition (b) containing other components. . Compositions (a) and (b) may be in any combination as long as they are mixed to form the aqueous dispersion of the present invention. Composition (b) is further divided into a plurality of compositions and supplied. You can also

  The chemical mechanical polishing aqueous dispersion can be used for chemical mechanical polishing by removing coarse abrasive grains by filtration if necessary. Preferably, those filtered using a PP (polypropylene) depth type filter having a pore diameter of 10 μm or less are suitably used. Preferably, a filter having a pore size of 5 μm or less can be used.

The manufacturing method of the multilayer circuit board of the present invention is characterized in that the wiring of the multilayer circuit board is formed using the chemical mechanical polishing aqueous dispersion of the present invention.

Hereinafter, the present invention will be described in detail by way of examples.
[1] Fabrication of substrate used for polishing performance evaluation (1) Fabrication of flatness evaluation substrate WPR-1201 varnish on a copper-clad laminate (substrate thickness: 0.6 mm, size: 10 cm square) whose surface was roughened (Photosensitive insulating resin composition manufactured by JSR Co., Ltd.) was spin-coated and heated on a hot plate at 110 ° C. for 3 minutes to produce a uniform coating film having a thickness of 10 μm. Thereafter, using an aligner (MA-100 manufactured by Karl Suss), UV light from a high-pressure mercury lamp is irradiated at a wavelength of 350 nm through a pattern mask having an L / S pattern with a pitch of 100 μm at a wavelength of 3,000 to 5,000 J / m 2. It exposed so that it might become. Subsequently, it was heated at 110 ° C. for 3 minutes (PEB) on a hot plate, immersed and developed at 23 ° C. for 60 seconds using an aqueous 2.38 wt% tetramethylammonium hydroxide (TMAH) solution, and then 120 ° C. in a convection oven. * 2 hours of heating was performed to form a cured insulating resin film having a groove pattern on the copper-clad laminate. After forming a copper seed layer by electroless plating on the obtained insulating resin cured film, a 10 μm copper plating layer is formed by electrolytic plating to obtain a flatness evaluation substrate in which copper is embedded in the groove pattern. It was.

(2) Preparation of substrate for copper polishing rate evaluation A substrate with a copper film of 10 um was obtained in the same manner as the substrate for flatness evaluation (1) except that the groove pattern of the insulating resin layer was not formed.

[2] Preparation of aqueous dispersion containing abrasive grains (1) Preparation of aqueous dispersion containing inorganic abrasive grains (a) Preparation of aqueous dispersion containing fumed silica particles Fumed silica particles (manufactured by Nippon Aerosil Co., Ltd., 2 kg of trade name “Aerosil # 90”) was dispersed in 6.7 kg of ion-exchanged water using an ultrasonic disperser and filtered through a filter having a pore diameter of 5 μm to prepare an aqueous dispersion containing fumed silica.

(B) Preparation of aqueous dispersion containing colloidal silica 70 g of 25 wt% ammonia water, 40 g of ion exchange water, 175 g of ethanol and 21 g of tetraethoxysilane were charged into a 2 liter flask and stirred at 180 rpm. The temperature was raised to 0 ° C. and stirring was continued for 2 hours at this temperature, followed by cooling to obtain a colloidal silica / alcohol dispersion having an average particle diameter of 70 nm. Subsequently, the operation of removing the alcohol content by adding an ion-exchanged water to the dispersion at a temperature of 80 ° C. by an evaporator is repeated several times, the alcohol content in the dispersion is removed, and the water having a solid content concentration of 8% by weight is removed. A dispersion was prepared.

(2) Preparation of aqueous dispersion containing abrasive grains composed of composite particles (c) Preparation of aqueous dispersion containing polymer particles 90 parts of methyl methacrylate, methoxypolyethylene glycol methacrylate (manufactured by Shin-Nakamura Chemical Co., Ltd., Product name “NK ester M-90G”, # 400) 5 parts, 4-vinylpyridine 5 parts, azo polymerization initiator (trade name “V50” manufactured by Wako Pure Chemical Industries, Ltd.) 2 parts, and ion-exchanged water 400 Was put into a 2 liter flask and heated to 70 ° C. with stirring in a nitrogen gas atmosphere and polymerized for 6 hours. As a result, an aqueous dispersion containing polymethyl methacrylate particles having an amino group cation and a functional group having a polyethylene glycol chain and an average particle diameter of 150 nm was obtained. The polymerization yield was 95%.

(D) Aqueous dispersion containing composite particles 100 parts of an aqueous dispersion containing 10% by weight of the polymethyl methacrylate-based particles obtained in (c) was put into a 2 liter flask, and 1 part of methyltrimethoxysilane was added. The mixture was added and stirred at 40 ° C. for 2 hours. Thereafter, the pH was adjusted to 2 with nitric acid to obtain an aqueous dispersion (e). Further, the pH of an aqueous dispersion containing 10% by weight of colloidal silica (manufactured by Nissan Chemical Co., Ltd., trade name “Snowtex O”) was adjusted to 8 with potassium hydroxide to obtain an aqueous dispersion (f). The zeta potential of the polymethyl methacrylate particles contained in the aqueous dispersion (e) was +17 mV, and the zeta potential of the silica particles contained in the aqueous dispersion (f) was −40 mV.

  Thereafter, 50 parts of the aqueous dispersion (f) are gradually added to 100 parts of the aqueous dispersion (e), mixed and stirred for 2 hours to obtain particles having silica particles attached to the polymethyl methacrylate particles. An aqueous dispersion containing was obtained. Next, 2 parts of vinyltriethoxysilane is added to this aqueous dispersion and stirred for 1 hour, then 1 part of tetraethoxysilane is added, the temperature is raised to 60 ° C., and stirring is continued for 3 hours, followed by cooling. As a result, an aqueous dispersion containing composite particles was obtained. The average particle size of the composite particles was 180 nm, and silica particles were attached to 80% of the surface of the polymethyl methacrylate particles.

(E) Aqueous dispersion containing calcium carbonate 200 g of high-purity calcium carbonate CS-3NA (manufactured by Ube Materials Co., Ltd.) is added to 800 g of ion-exchanged water and stirred at a rotation speed of 6000 rpm using a homomixer (manufactured by Primics Co., Ltd.). The mixture was stirred for 1 hour to obtain an aqueous dispersion containing 20% by weight of calcium carbonate. The average particle size of this calcium carbonate was 480 nm.

<Preparation of aqueous solution of polyvinylpyrrolidone>
A 500 mL flask was charged with 60 g of degassed N-vinyl-2-pyrrolidone and 240 g of degassed water. This was heated to 60 ° C. with stirring in a nitrogen stream, and 0.3 g of a 10% by mass aqueous sodium sulfite solution and 0.3 g of a 10% by mass aqueous t-butyl hydroperoxide solution were added. After stirring at 60 ° C. for 3 hours, 1.8 g of a 10% by mass sodium sulfite aqueous solution and 1.2 g of a 10% by mass t-butyl hydroperoxide aqueous solution were added, and the stirring was further continued for 3 hours. The reaction mixture was diluted with ion-exchanged water to obtain a 20% by mass aqueous polyvinylpyrrolidone solution.
In addition, about the polyvinyl pyrrolidone prepared here, the weight in conversion of polyethylene glycol measured by water-based gel permeation chromatography using 0.1 mol / L NaCl aqueous solution / acetonitrile = 80/20 (vol / vol) as an eluent. The average molecular weight (Mw) was 1,000,000. In addition, the K value obtained by the Fikenscher method was 95.

[3] Preparation of Chemical Mechanical Polishing Aqueous Dispersion A predetermined amount of the aqueous dispersion prepared in [2] is put into a polyethylene bottle having a capacity of 1 liter, and Table 1, Table 2, and Table 3 show this. The described compounds were added so as to have respective contents, and stirred sufficiently. Then, it filtered with the filter of 5 micrometers of hole diameters, and obtained the aqueous dispersion for chemical mechanical polishing of Examples 1-16 and Comparative Examples 1-10.

[4] Polishing of substrate A substrate with a copper film having no wiring pattern using the aqueous dispersions of Examples 1 to 16 and Comparative Examples 1 to 10, and a substrate for evaluating flatness in which copper is embedded in the groove pattern described above Polishing was performed under the following conditions.
Polishing device: Lapmaster LM15
Polishing pad: IC1000 (made by Nitta Haas)
Carrier load: 150 hPa
Surface plate rotation speed: 90pm
Abrasive supply amount: 100 ml / min

The copper polishing rate was calculated using the following calculation formula from the polishing result of the substrate with a copper film without a wiring pattern.
Polishing speed (μm / min) = polishing amount (μm) / polishing time (min)
The polishing amount was calculated by using the following formula as copper density: 8.9 g / cm 3.
Polishing amount (μm) = (weight before polishing (g) −weight after polishing (g)) / substrate area (cm ² ) * copper density (g / cm ³ ) * 10 ⁴
Moreover, the surface after grinding | polishing was observed with the optical microscope, and the presence or absence of the scratch was confirmed. The results are shown in Table 1, Table 2 and Table 3.

[5] Evaluation of dishing When polishing an initial surplus film [thickness X (μm)] when a wiring material is embedded in a groove or the like at a polishing rate V (μm / min), it is originally X / V (min) The purpose should be achieved by polishing for only time, but in the actual manufacturing process, excessive polishing (over polishing) exceeding X / V (min) is performed to remove the wiring material remaining in the part other than the groove. ing. At this time, the wiring portion may be excessively polished, resulting in a concave shape. Such a concave wiring shape is referred to as “dishing” and is not preferable because it reduces the yield of manufactured products. Evaluation of such dishing was performed using a stylus type step gauge (manufactured by KLA-Tencor, model “P-10”) using 50 μm wiring of the substrate (a) and the substrate (b).
The polishing time in the dishing evaluation is a value (X / V) (minute) obtained by dividing the initial excess copper film [thickness X (μm)] by the polishing rate V (μm / minute) obtained in [4]. ) Times 1.5 (minutes). The dishing evaluation results are shown in Table 1, Table 2, and Table 3.

  According to the results of Tables 1 and 2, in the chemical mechanical polishing aqueous dispersions of Examples 1 to 16, the copper polishing rate is sufficiently high at 4 μm / min or more. Further, it can be seen that the dishing of the 50 μm wiring is as small as 1.0 μm or less and has a good overpolish margin. Furthermore, no scratches on the copper surface are observed and the surface has a good polished surface. On the other hand, as shown in Table 3, in (A) Comparative Example 1 containing no organic acid, the polishing rate was insufficient, and (B) in Comparative Example 2 containing no surfactant, the polishing rate was sufficient, Comparative Examples 3, 4 and 5 which do not contain (C) oxidizing agent, (D) abrasive grains, (E) no ammonia or ammonium salt, and the total amount of (A) and (E) components In Comparative Example 6 in which is less than 1% by weight, the polishing rate is 1 μm / min or less, which is insufficient. Further, Comparative Example 7 in which the total amount of the component (A) and the component (E) exceeds 15% by weight has a problem that the polishing rate is sufficient but dishing is large. Further, both Comparative Example 8 and Comparative Example 9 in which the ratio of the concentration of the component (C) and the total concentration of the components (A) and (E) are out of the range of 1: 1 to 1:50 are polishing rates. And the dishing increase, and the polishing performance is inferior.

  According to the present invention, the excess wiring material on the display material substrate can be polished at a high polishing rate, while ensuring in-plane uniformity of the substrate and suppressing variation in flatness within the polished surface. An achievable chemical mechanical polishing aqueous dispersion can be obtained, which is useful in the production of display materials.

Claims (7)

(A) an organic acid, (B) a surfactant, (C) an oxidizing agent, (D) an abrasive, (E) one or more compounds selected from ammonia and an ammonium salt,
The total concentration of the component (A) and the component (E) is 1 to 15% by weight with respect to the total weight of the aqueous dispersion,
A copper or copper alloy provided on an organic resin insulating substrate in which the ratio of the concentration of the component (C) and the total concentration of the component (A) and the component (E) is 1: 1 to 1:50. A chemical mechanical polishing aqueous dispersion for polishing a wiring layer. 2. The chemical mechanical polishing aqueous dispersion according to claim 1, wherein the component (D) includes one or more selected from silica particles, organic polymer particles, organic-inorganic composite particles, and calcium carbonate particles. The chemical mechanical polishing aqueous dispersion according to claim 1, wherein the component (A) is an amino acid. The chemical mechanical polishing aqueous dispersion according to claim 1, wherein the component (B) is one or more compounds selected from potassium dodecylbenzenesulfonate and ammonium dodecylbenzenesulfonate. The chemical mechanical polishing aqueous dispersion according to claim 1, further comprising (F) a water-soluble polymer compound. A method for producing a multilayer circuit board, comprising forming a conductor wiring by using the chemical mechanical polishing aqueous dispersion according to any one of claims 1 to 5. A multilayer circuit board manufactured by the manufacturing method according to claim 6.