JP2008103746A - Method for manufacturing metal polishing solution - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a metal polishing solution capable of easily preparing a metal polishing solution by adding a diluent and the like to a high concentration-polishing solution material if an actual polishing is performed by using the high concentration-polishing solution material for transport, storage and the like. <P>SOLUTION: The method for manufacturing a metal polishing solution constituted by containing an oxidizer, a metal oxide resolvent, a passivation forming agent, a solubilizing agent of the passivation forming agent, and water includes a mixing step that mixes a first component containing the oxidizer, a second component containing at least one component out of a component group consisting of the metal oxide resolvent, the passivation forming agent, and the solubilizing agent of the passivation forming agent, and the diluent. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a metal polishing liquid particularly suitable for a wiring process of a semiconductor device and a polishing method using the metal polishing liquid, and more particularly to a method for manufacturing a metal polishing liquid.

  In recent years, new microfabrication techniques have been developed along with higher integration and higher performance of semiconductor integrated circuits (hereinafter referred to as LSIs). A chemical mechanical polishing (hereinafter referred to as CMP) method is one of them, and is a technology frequently used in the LSI manufacturing process, particularly in the multilayer wiring formation process, flattening of the interlayer insulating film, metal plug formation, embedded wiring formation, etc. It is. This technique is disclosed in Patent Document 1, for example.

  Recently, in order to improve the performance of LSIs, the use of copper alloys as wiring materials has been attempted. However, it is difficult to finely process the copper alloy by the dry etching method frequently used in the formation of the conventional aluminum alloy wiring. Therefore, a so-called damascene method is mainly employed in which a copper alloy thin film is deposited and embedded on an insulating film in which grooves have been formed in advance, and the copper alloy thin film other than the grooves is removed by CMP to form embedded wiring. . This technique is disclosed in Patent Document 2, for example.

  A general method of metal CMP is to apply a polishing pad on a circular polishing platen (platen), immerse the polishing pad surface with a metal polishing liquid, and press the surface on which the metal film of the substrate is formed. The polishing platen is rotated in a state where a predetermined pressure (hereinafter referred to as polishing pressure) is applied from the back surface, and the metal film on the convex portion is removed by mechanical friction between the polishing liquid and the convex portion of the metal film.

  The metal polishing liquid used in CMP is generally composed of an oxidizing agent and solid abrasive grains, and a metal oxide dissolving agent and a protective film forming agent are further added as necessary. It is considered that the basic mechanism of CMP is to first oxidize the surface of a metal film by oxidation and scrape the oxidized layer with solid abrasive grains. Since the oxide layer on the metal surface of the recess does not touch the polishing pad so much and does not have the effect of scraping off by the solid abrasive grains, the metal layer of the projection is removed and the substrate surface is flattened with the progress of CMP. This detail is disclosed in Non-Patent Document 1.

  In general, it is considered effective to add a metal oxide solubilizer to increase the polishing rate by CMP. This can be interpreted as the effect of scraping off by the solid abrasive grains is increased by dissolving the metal oxide grains scraped off by the solid abrasive grains in the polishing liquid. Although the polishing rate by CMP is improved by the addition of the metal oxide dissolving agent, the oxide layer on the surface of the metal film in the recess is also etched (dissolved). As a result, when the metal film surface is exposed, the metal film surface is further oxidized by the oxidizing agent, and when this is repeated, etching of the metal film in the recesses proceeds. For this reason, when a metal oxide solubilizer is added, a phenomenon occurs in which the central portion of the surface of the metal wiring embedded after polishing is depressed like a dish (hereinafter referred to as dishing), and the planarization effect is impaired. Therefore, in order to prevent this, a protective film forming agent is further added. In such a metal polishing liquid, the oxide layer on the surface of the metal film in the recesses is not etched so much, but the particles of the oxidized layer are efficiently dissolved and the polishing rate by CMP is increased so that the polishing rate by CMP is high. It is important to balance the effect of the protective film forming agent.

  Thus, by adding the metal oxide solubilizer and the protective film forming agent and adding the effect of chemical reaction, the CMP rate (polishing rate by CMP) is improved and the surface of the metal layer to be CMP is damaged (damage). Can also be reduced.

  However, the following problems (1) to (4) occur when embedded wiring is formed by CMP using a conventional metal polishing liquid containing solid abrasive grains.

(1) Occurrence of dishing that isotropically corrodes the surface central portion of the embedded metal wiring (2) Occurrence of polishing scratches (scratches) derived from solid abrasive grains (3) Residual surface of the substrate after polishing The complexity of the cleaning process to remove the solid abrasive grains (4) The cost of the solid abrasive grains themselves and the increase in costs due to waste liquid treatment Also, most of the metal polishing liquid is water. A large space is required for storage and manufacturing due to the container for storing and transporting, storage on the transportation and polishing side, tank capacity required for the polishing equipment, etc. This was an obstacle to automating the supply of liquid to the polishing machine. Furthermore, an increase in costs associated with the recycling of transport containers is also a major problem.

  These problems can be improved by using a concentrate of a metal polishing liquid that does not contain a large amount of solid abrasive grains. Thereby, the production cost of the polishing liquid manufacturer is reduced, and as a result, the cost of the diluted concentrated liquid can be reduced. Further, the use of the concentrated liquid has the advantage that it is possible to cope with mass production without making new capital investment because it is not necessary to increase the scale of the polishing liquid production facility. In consideration of the effect obtained by using the concentrate, it is desirable that a concentrate of 10 times or more can be prepared.

On the other hand, in order to suppress corrosion of the copper alloy during dishing and polishing and to form a highly reliable LSI wiring, a metal oxide dissolving agent composed of aminoacetic acid or amide sulfuric acid such as glycine and benzotriazole as a protective film forming agent (Hereinafter, referred to as BTA) has been proposed. This technique is described in Patent Document 3, for example.
U.S. Pat. No. 4,944,836 JP-A-2-278822 Journal of Electrochemical Society, Vol. 138, No. 11 (1991), pages 3460-3464 JP-A-8-83780

  However, due to the low solubility of BTA in water (2 g / 20 ° C. water 100 cc), it was not possible to concentrate 10 times in some metal polishing liquids (for example, concentration of metal polishing liquid containing 0.2% by weight of BTA). Is possible up to 5 times, with 10 times being deposited at 0 ° C. or less). Therefore, a metal polishing liquid that can concentrate the polishing liquid 10 times or more and does not precipitate BTA in the concentrated liquid in a normal environment of 0 ° C. or higher is desired.

  It is an object of the present invention to provide a metal polishing liquid that can be easily prepared by diluting a high concentration metal polishing liquid material and realizes formation of a highly reliable embedded pattern of a metal film. To do. Furthermore, an object of this invention is to provide the manufacturing method of this metal polishing liquid, the metal polishing liquid material used therefor, and the polishing method using the said polishing liquid.

  In order to achieve the above object, there is provided a metal polishing slurry containing an oxidizing agent, a metal oxide dissolving agent, a protective film forming agent, a solubilizing agent for the protective film forming agent, and water.

  The metal polishing liquid may further contain abrasive grains, but may not substantially contain solid abrasive grains. When solid abrasive grains are included, high-speed polishing can be realized. Further, when solid abrasive grains are not included, polishing scratches are dramatically reduced because CMP proceeds by friction with a polishing pad that is much mechanically softer than solid abrasive grains.

  As a material for preparing this metal polishing liquid, a metal polishing liquid material containing a metal oxide solubilizer, a protective film forming agent, and a solubilizing agent for the protective film forming agent is provided. The metal-polishing liquid material may further contain an oxidizing agent, water, and / or abrasive grains.

  If this metal polishing liquid material is used, the metal polishing liquid can be easily prepared by diluting it and adding components as needed. Therefore, the present invention provides a method for producing a metal polishing liquid comprising a dilution step of diluting a metal polishing liquid material with a diluent.

  In addition, as a method for producing a metal polishing liquid using a metal polishing liquid material having two or more components as described above, in the present invention, the first component and the second component described above, dilution, Provided is a method for producing a metal polishing slurry comprising a mixing step of mixing agents in a desired order. The order of mixing is not particularly limited, and can be appropriately selected according to the properties of the compound used, the temperature of the liquid to be mixed, and the like.

  That is, this invention relates to the manufacturing method of the polishing liquid for metals of the following (1)-(14).

(1) A method for producing a metal polishing slurry comprising an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, a solubilizing agent for the protective film forming agent, and water,
A first component comprising an oxidant;
Polishing for metals including a mixing step of mixing a second component containing at least one component of a component group consisting of a metal oxide solubilizer, a protective film forming agent and a solubilizing agent for the protective film forming agent, and a diluent Liquid manufacturing method.

(2) The metal polishing slurry according to (1), wherein the first component, the second component, and a diluent are mixed by any one of the following methods (1) to (5). Manufacturing method.

(1) Method of mixing component A and component B and diluting the mixture with a diluent
(2) Method of diluting component A with diluent and mixing it with component B
(3) Method of diluting component B with diluent and mixing it with component A
(4) Method of diluting component A and component B with a diluent, and mixing diluted component A and diluted component B
(5) Method of mixing component A, component B and diluent almost simultaneously (3) The second component is diluted with the diluent, and this is mixed with the first component (1) The manufacturing method of the polishing liquid for metals of (2).

(4) The method for producing a metal polishing slurry according to any one of (1) to (3), wherein the diluent is water or an aqueous solution for dilution.

(5) The said 2nd component is a manufacturing method of the metal polishing liquid in any one of said (1)-(4) containing a protective film formation agent and a solubilizing agent.

(6) The method for producing a metal polishing slurry according to any one of (1) to (5), wherein the second component includes a metal oxide solubilizer, a protective film forming agent, and a solubilizing aid.

(7) The dissolution aid is one or more of ester, ether, polysaccharide, amino acid salt, polycarboxylic acid, polycarboxylate, vinyl polymer, sulfonic acid, sulfonate, and amide ( The manufacturing method of the metal polishing liquid in any one of 1)-(6).

(8) The method for producing a metal polishing slurry according to any one of (1) to (7), wherein the dissolution aid is a solvent having a solubility of the protective film forming agent of 25 g / L or more.

(9) The method for producing a metal polishing slurry according to any one of (1) to (8), wherein the dissolution aid is at least one of alcohol, ether, and ketone.

(10) The method for producing a metal polishing slurry according to any one of (1) to (9), wherein in the mixing step, the first component is maintained at 40 ° C. or lower.

(11) Any of the above (1) to (10), wherein at least a part of the protective film forming agent is a solid having an average particle size of 100 μm or less and is dissolved or dispersed in the metal polishing slurry by the mixing step. A method for producing such metal polishing liquid.

(12) The polishing amount for a metal according to any one of (1) to (11), wherein a blending amount of the solvent is less than 50 g with respect to a total amount of 100 g of the first component and the second component. Liquid manufacturing method.

(13) The method for producing a metal-polishing liquid according to any one of (1) to (12), further comprising a step of further mixing abrasive grains.

(14) A method for producing a metal polishing slurry comprising an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, a solubilizing aid for the protective film forming agent, and water.
A first component including at least one component of a component group consisting of an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, and a solubilizing agent for the protective film forming agent;
A second component comprising at least one component of the remaining components of the component group;
The manufacturing method of the polishing liquid for metals including the mixing process which mixes a diluent.

  The first component may further contain a protective film forming agent and a solubilizing agent as necessary. Moreover, the 1st and 2nd component may contain the other component as needed, respectively.

  Further, it is desirable that at least a part of the protective film forming agent is a solid having an average particle diameter of 100 μm or less, and is dissolved or dispersed in the metal polishing liquid by this mixing step. In the present specification, the number average particle diameter is simply referred to as an average particle diameter unless otherwise specified.

  Unlike conventional polishing liquids, the metal polishing liquid of the present invention uses a high-concentration metal polishing liquid material that can be easily prepared by dilution, thereby producing metal polishing liquid production costs. It is possible to reduce the capacity of a container for transporting, storage on the transporting and polishing side, a tank of a polishing apparatus, and the like.

  In this metal polishing liquid, a dissolution aid is added to the metal polishing liquid mainly for the purpose of improving the solubility of the protective film forming agent in water. As a result, it is possible to prepare a metal polishing liquid material having a broader range and a higher concentration according to the polishing characteristics.

A. Components Next, each component of the metal polishing liquid material and metal polishing liquid of the present invention will be described.

(1) Solubilizing agent In the present invention, the solubilizing agent is preferably a solvent having a solubility of the protective film forming agent of 25 g / L or more, or a surfactant. These may be used alone or in combination.

a. Surfactant By adding a surfactant, the surfactant is adsorbed on the hydrophobic group of the protective film forming agent, and the hydrophilic group of the surfactant increases the compatibility with water, thereby improving the solubility. be able to.

  Examples of the surfactant include esters, ethers, polysaccharides, amino acid salts, polycarboxylic acids, polycarboxylates, vinyl polymers, sulfonic acids, sulfonates, and amides. These may be used alone or in combination of one or more.

  The surfactant includes an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant. Specific examples suitable for the present invention are listed below.

  Examples of the anionic surfactant include carboxylate, sulfonate, sulfate ester salt, and phosphate ester salt.

  Examples of the carboxylate include soap, N-acyl amino acid salt, polyoxyethylene alkyl ether carboxylate, polyoxypropylene alkyl ether carboxylate, and acylated peptide.

  Examples of the sulfonate include alkyl sulfonate, alkyl benzene sulfonate, alkyl naphthalene sulfonate, naphthalene sulfonate, sulfosuccinate, α-olefin sulfonate, and N-acyl sulfonate.

  Examples of sulfate salts include sulfated oils, alkyl sulfates, alkyl ether sulfates, polyoxyethylene allyl ether sulfates, polyoxypropylene alkyl allyl ether sulfates, and alkylamide sulfates.

  Examples of phosphoric acid ester salts include alkyl phosphates, polyoxyethylene alkyl allyl ether phosphates, and polyoxypropylene alkyl allyl ether phosphates.

  Examples of the cationic surfactant include aliphatic amine salts, aliphatic quaternary ammonium salts, benzalkonium chloride salts, benzethonium chloride, pyridinium salts, imidazolinium salts, and the like.

  Examples of amphoteric surfactants include carboxybetaine type, aminocarboxylate, imidazolinium betaine, lecithin, alkylamine oxide and the like.

  Nonionic surfactants include ether type, ether ester type, ester type, and nitrogen-containing type. Moreover, a fluorine-type surfactant can also be used conveniently.

  Examples of the ether type include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, alkylallyl formaldehyde condensed polyoxyethylene ether, polyoxyethylene polyoxypropylene block polymer, polyoxyethylene polyoxypropylene alkyl ether and the like.

  Examples of ether ester types include glycerin ester polyoxyethylene ether, sorbitan ester polyoxyethylene ether, sorbitol ester polyoxyethylene ether, and the like.

  Examples of the ester type include polyethylene glycol fatty acid ester, glycerin ester, polyglycerin ester, sorbitan ester, propylene glycol ester, and sucrose ester.

  Examples of the nitrogen-containing type include fatty acid alkanolamide, polyoxyethylene fatty acid amide, polyoxyethylene alkylamide and the like.

Furthermore, esters such as glycerin ester, sorbitan ester, methoxyacetic acid, ethoxyacetic acid, 3-ethoxypropionic acid and alanine ethyl ester;
Polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol alkyl ether, polyethylene glycol alkenyl ether, alkyl polyethylene glycol, alkyl polyethylene glycol alkyl ether, alkyl polyethylene glycol alkenyl ether, alkenyl polyethylene glycol, alkenyl polyethylene glycol alkyl ether, alkenyl polyethylene glycol Alkenyl ether, polypropylene glycol alkyl ether, polypropylene glycol alkenyl ether, alkyl polypropylene glycol, alkyl polypropylene glycol alkyl ether, alkyl polypropylene glycol alkenyl ether, alkenyl poly Propylene glycol, ethers such as alkenyl polypropylene glycol alkyl ethers and alkenyl polypropylene glycol alkenyl ethers;
Sulfonic acids such as methyl tauric acid, methyl sulfate, butyl sulfate, vinyl sulfonic acid, 1-allyl sulfonic acid, 2-allyl sulfonic acid, methoxymethyl sulfonic acid, ethoxymethyl sulfonic acid, 3-ethoxypropyl sulfonic acid and sulfosuccinic acid;
Methyl taurate ammonium salt, methyl taurate sodium salt, methyl sodium sulfate salt, ethyl ammonium sulfate, butyl ammonium sulfate, vinyl sulfonic acid sodium salt, 1-allyl sulfonic acid sodium salt, 2-allyl sulfonic acid sodium salt, methoxy Methylsulfonic acid sodium salt, ethoxymethylsulfonic acid ammonium salt, 3-ethoxypropylsulfonic acid sodium salt,
And sulfonates such as sulfosuccinic acid sodium salt;
Examples of suitable surfactants include amides such as propionamide, acrylamide, methylurea, nicotinamide, succinic acid amide, and sulfanilamide.

  However, when the object to be polished is a silicon substrate for a semiconductor integrated circuit or the like, contamination with an alkali metal, an alkaline earth metal, a halide, or the like is not desirable, so an acid or an ammonium salt thereof is desirable. Note that this is not the case when the object to be polished is a glass substrate or the like.

  The compounding amount of the surfactant is such that an oxidizing agent and an oxidizing agent are used in a metal polishing liquid (that is, in a state where an additive is added to the metal polishing liquid material as necessary and diluted with a diluent and usable as a polishing liquid). It is preferable to set it as 0.01-3g with respect to 100g of total amounts of a metal dissolving agent, a protective film formation agent, surfactant, and water, It is more preferable to set it as 0.03-1g, 0.1-0.8g It is particularly preferable that If the blending amount is less than 0.01 g, the effect of adding the surfactant does not appear, and if it exceeds 3 g, the CMP rate tends to decrease.

b. Solvent For the purpose of improving the solubility of the protective film forming agent in water, in the present invention, a solvent having a solubility of the protective film forming agent of 25 g / L or more is added to the polishing liquid material. The solubility of the protective film forming agent in this solvent is preferably 40 g / L or more, more preferably 50 g / L or more, and it is particularly desirable to use a good solvent.

  Examples of the solvent as a solubilizing agent suitable for the present invention include organic solvents such as alcohols, ethers and ketones. These may be used alone or in combination of any two or more.

In the present invention, as a solvent suitable for use as a solubilizing agent,
Methanol, ethanol, 1-propanol, 2-propanol, 2-propyn-1-ol, allyl alcohol, ethylene cyanohydrin, 1-butanol, 2-butanol (S)-(+)-2-butanol, 2-methyl-1 -Propanol, t-butyl alcohol, perfluoro-t-butyl alcohol, t-pentyl alcohol, 1,2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 2 , 3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, glycerin, 2-ethyl-2- (hydroxymethyl) -1,3 Alcohols such as propanediol, 1,2,6-hexanetriol;
Dioxane, trioxane, tetrahydrofuran, diethylene glycol diethyl ether, 2-methoxyethanol, 2-ethoxyethanol, 2,2- (dimethoxy) ethanol, 2-isopropoxyethanol, 2-butoxyethanol, 1-methoxy-2-propanol, 1- Ethoxy-2-propanol, furfuryl alcohol, tetrahydrofurfuryl alcohol, ethylene glycol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, tetraethylene glycol, dipropylene glycol , Dipropylene glycol monomethyl ether, dipro Glycol monoethyl ether, tripropylene glycol monomethyl ether, diacetone alcohol, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, ethers such as diethylene glycol monoethyl ether acetate;
Examples include ketones such as acetone, methyl ethyl ketone, acetylacetone, and cyclohexanone.

  Among these solvents, methanol, ethanol, 2-propanol, tetrahydrofuran, ethylene glycol, acetone, and methyl ethyl ketone are more preferable.

  Although there is no restriction | limiting in particular in the compounding quantity of this solvent, it is preferable to set it as less than 50g with respect to 100g of total amounts of metal polishing liquid materials, and it is more preferable to set it as less than 25g. When the blending amount is 50 g or more, unlike the case where the state of the polishing interface is an aqueous system, the CMP rate may decrease.

(2) Protective film forming agent The protective film forming agent forms a protective film on the metal surface. Examples of the protective film forming agent include nitrogen-containing compounds such as ammonia, alkylamines, amino acids, imines, and azoles and salts thereof, sulfur-containing compounds such as mercaptans, and polysaccharides, polycarboxylic acids, polycarboxylates, and vinyl-based compounds. Water-soluble polymers such as polymers are listed. These may be used alone or in combination of two or more.

As a protective film forming agent suitable for the present invention, for example,
ammonia;
Alkylamines such as dimethylamine, trimethylamine, triethylamine, propylenediamine, and amines such as ethylenediaminetetraacetic acid (EDTA), sodium diethyldithiocarbamate and chitosan;
Glycine, L-alanine, β-alanine, L-2-aminobutyric acid, L-norvaline, L-valine, L-leucine, L-norleucine, L-isoleucine, L-alloisoleucine, L-phenylalanine, L-proline, Sarcosine, L-ornithine, L-lysine, taurine, L-serine, L-threonine, L-allothreonine, L-homoserine, L-tyrosine, 3,5-diodo-L-tyrosine, β- (3 4-dihydroxyphenyl) -L-alanine, L-thyroxine, 4-hydroxy-L-proline, L-cystine, L-methionine, L-ethionine, L-lanthionine, L-cystathionine, L-cystine, L-cysteic acid , L-aspartic acid, L-glutamic acid, S- (carboxymethyl) -L-cysteine, 4-aminobutyric acid, L Asparagine, L-glutamine, azaserine, L-arginine, L-canavanine, L-citrulline, δ-hydroxy-L-lysine, creatine, L-quinurenin, L-histidine, 1-methyl-L-histidine, 3-methyl Amino acids such as L-histidine, ergothioneine, L-tryptophan, actinomycin C1, apamin, angiotensin I, angiotensin II and antipine;
Dithizone, cuproin (2,2′-biquinoline), neocuproin (2,9-dimethyl-1,10-phenanthroline), bathocuproine (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and cupelazone ( Imines such as biscyclohexanone oxalyl hydrazone);
Benzimidazole-2-thiol, 2- [2- (benzothiazolyl)] thiopropionic acid, 2- [2- (benzothiazolyl)] thiobutyric acid, 2-mercaptobenzothiazole, 1,2,3-triazole, 1,2, 4-triazole, 3-amino-1H-1,2,4-triazole, benzotriazole, 1-hydroxybenzotriazole, 1-dihydroxypropylbenzotriazole, 2,3-dicarboxypropylbenzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-methoxycarbonyl-1H-benzotriazole, 4-butoxycarbonyl-1H-benzotriazole, 4-octyloxycarbonyl-1H-benzotriazole, 5-hexylbenzotriazol N- (1,2,3-benzotriazolyl-1-methyl) -N- (1,2,4-triazolyl-1-methyl) -2-ethylhexylamine, tolyltriazole, naphthotriazole, bis [( Azoles such as 1-benzotriazolyl) methyl] phosphonic acid;
Mercaptans such as nonyl mercaptan, dodecyl mercaptan, triazine thiol, triazine dithiol, triazine trithiol;
Polysaccharides such as alginic acid, pectic acid, carboxymethylcellulose, curdlan and pullulan;
Amino acid salts such as glycine ammonium salt and glycine sodium salt;
Polyaspartic acid, polyglutamic acid, polylysine, polymalic acid, polymethacrylic acid, polymethacrylic acid ammonium salt, polymethacrylic acid sodium salt, polyamic acid, polymaleic acid, polyitaconic acid, polyfumaric acid, poly (p-styrenecarboxylic acid), poly Polycarboxylic acids such as acrylic acid, polyacrylamide, aminopolyacrylamide, ammonium polyacrylate, sodium polyacrylate, ammonium polyamic acid, sodium polyamic acid and polyglyoxylic acid and salts thereof;
Examples thereof include vinyl polymers such as polyvinyl alcohol, polyvinyl pyrrolidone and polyacrolein.

  Among these protective film forming agents, chitosan, ethylenediaminetetraacetic acid, L-tryptophan, cuperazone, triazinedithiol, benzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole butyl ester, tolyltriazole, naphthotriazole, Polymalic acid, polyacrylic acid, polyacrylamide, polyacrylic acid ammonium salt, and polyvinyl alcohol are preferable for achieving both a high CMP rate and a low etching rate.

  The compounding amount of the protective film forming agent should be 0.0001 mol to 0.05 mol with respect to 100 g of the total amount of the oxidizing agent, metal oxide solubilizer, protective film forming agent, solubilizing agent and water in the metal polishing liquid. Is preferable, 0.0003 mol to 0.005 mol is more preferable, and 0.0005 mol to 0.0035 mol is particularly preferable. If this amount is less than 0.0001 mol, it tends to be difficult to suppress etching, and if it exceeds 0.05 mol, the CMP rate tends to be low.

  Further, among the protective film forming agents used for the preparation of the metal polishing liquid material, the blending amount of the water solubility at room temperature of less than 5% by weight should be within twice the solubility in water at room temperature. Preferably, it is more preferably 1.5 times or less. That is, normally, the compounding amount of the protective film forming agent is 0.0001 to 0.05 mol, preferably 0.0003 to 0.05 mol, and preferably 0.0005 to 0.05 mol with respect to 100 g of the total amount of the polishing liquid material. More preferably, it is 0035 mol. If the amount is more than twice the solubility, it becomes difficult to prevent precipitation when the concentrated product is cooled to 5 ° C.

  In the present invention, when a metal polishing liquid material is prepared using a solid protective film forming agent, an average particle diameter of 100 μm or less is used, and this is used as a metal polishing liquid material (two or more components not mixed with each other). When the polishing liquid material is constituted by an element (single substance or composition), it is preferably dissolved or dispersed in at least one of the constituent elements (single substance or composition). Thus, the protective film forming agent with a small particle diameter can be obtained by pulverization or the like. Thus, if a thing with a small particle size is used, since a surface area will become large, a melt | dissolution rate can be accelerated | stimulated. Moreover, even when it is dispersed as small particles in a state where it cannot be completely dissolved, it can be dissolved in a short time when other components and / or diluents are mixed. Therefore, the average particle size is preferably 50 μm or less, and more preferably 20 μm or less.

(3) Oxidizing agent The oxidizing agent used in the present invention is a compound capable of oxidizing a metal. Suitable oxidizing agents for the present invention include hydrogen peroxide, nitric acid, potassium periodate, hypochlorous acid, and ozone water. Of these oxidizing agents, hydrogen peroxide (H ₂ O ₂ ) is particularly preferable. In the case where the object to be polished is a silicon substrate including an integrated circuit element, contamination with alkali metal, alkaline earth metal, halide, or the like is not desirable. Therefore, an oxidizing agent that does not include a nonvolatile component is desirable. However, hydrogen peroxide is most suitable because ozone water has a severe compositional change over time. Note that in the case where the object to be polished is a glass substrate or the like that does not include a semiconductor element, an oxidizing agent that includes a nonvolatile component may be used.

  The compounding amount of the oxidizing agent is 0.003 mol to 0.7 mol with respect to 100 g of the total amount of the oxidizing agent, the metal oxide dissolving agent, the protective film forming agent, the solubilizing agent and water in the metal polishing liquid. Preferably, 0.03 mol to 0.5 mol is more preferable, and 0.2 mol to 0.3 mol is particularly preferable. If the amount is less than 0.003 mol, metal oxidation may be insufficient and the CMP rate may be low, and if it exceeds 0.7 mol, the polished surface tends to be rough. In addition, the compounding quantity of the oxidizing agent in metal polishing liquid material shall be 0.03-0.7 mol normally with respect to 100g of whole quantity. This blending amount is preferably 0.3 to 0.5 mol, and more preferably 0.2 to 0.3 mol, with respect to the total amount of 100 g.

(4) Metal Oxide Solubilizer As the metal oxide solubilizer, a water-soluble compound is desirable, and an organic acid, sulfuric acid, or an ammonium salt thereof is preferable for the present invention. These may be used alone or in combination of two or more compounds. These compounds may be added in the form of an aqueous solution when preparing an abrasive or an abrasive material.

As a specific example of the metal oxide solubilizer,
Formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid , N-octanoic acid, 2-ethylhexanoic acid, benzoic acid, glycolic acid, salicylic acid, glyceric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, phthalic acid, malic acid, Organic acids such as tartaric acid and citric acid;
Inorganic acids such as sulfuric acid, nitric acid, chromic acid;
ammonia;
Salts such as ammonium salts of the above organic acids or inorganic acids (for example, ammonium persulfate, ammonium nitrate, ammonium chloride, etc.);
Etc. These may be used alone or in combination of two or more.

  Of these compounds, formic acid, malonic acid, malic acid, tartaric acid, and citric acid include copper, copper alloy, copper oxide, or copper alloy oxide film (or at least one metal layer of these) Suitable for laminated film). In particular, malic acid, tartaric acid, and citric acid are preferable in that the etching rate can be effectively suppressed while maintaining a practical CMP rate.

The compounding amount of the metal oxide dissolving agent in the present invention is 0.000001 to 0.005 mol with respect to 100 g of the total amount of the oxidizing agent, the metal oxide dissolving agent, the protective film forming agent, the solubilizing agent and water in the metal polishing liquid. It is preferable to be 0.00005 mol to 0.0025 mol, and it is particularly preferable to be 0.0005 mol to 0.0015 mol. If this amount exceeds 0.005 mol, it tends to be difficult to suppress etching. In addition, the compounding quantity of the metal oxide solution in the metal polishing liquid material is usually 1 × 10 ^{−6 to} 0.005 mol and 5 × 10 ^{−5 to} 0.0025 mol with respect to 100 g of the total amount of the polishing liquid material. Is preferable, and it is more preferable to set it as 0.0005-0.0015 mol.

(5) Abrasive Grain The metal-polishing liquid of the present invention may or may not contain solid abrasive grains substantially.

  In the case of using abrasive grains, the order of mixing and the mixing target are not particularly limited. When the metal polishing liquid material is composed of two or more components (single substance or composition) that are not mixed with each other, any of the components (single substance or composition) contains abrasive grains. The abrasive grains may be included in two or more components.

As an abrasive, for example,
Inorganic abrasives such as silica, alumina, ceria, titania, zirconia, germania, silicon carbide;
Any of organic abrasive grains such as polystyrene, polyacryl, polyvinyl chloride, etc. may be used, but the dispersion stability in the polishing liquid is good, the number of scratches generated by CMP is small, and the average particle diameter is 100 nm. The following colloidal silica and colloidal alumina are preferred. The average particle size of the abrasive grains is more preferably 20 nm or less, for example, where the barrier layer polishing rate is higher and the silicon dioxide polishing rate is lower.

  Colloidal silica is known for its production by hydrolysis of silicon alkoxide or ion exchange of sodium silicate, and colloidal alumina is known for its production by hydrolysis of aluminum nitrate.

  The blending amount of the abrasive grains is 0 with respect to the total weight of the metal polishing liquid (that is, a state in which an additive is added to the metal polishing liquid material as necessary and diluted with a diluent and usable as a polishing liquid). 0.01 to 10% by weight is preferable, and 0.05 to 5% by weight is more preferable. If it is 0.01% by weight or less, the effect of containing abrasive grains is not seen, and if it is 10% by weight or more, the polishing rate by CMP is saturated, and even if it is added more than that, no increase is seen. In addition, it is preferable to set it as 0.01-10 weight% with respect to the polishing liquid material whole quantity, and, as for the compounding quantity of the abrasive grain in the metal-polishing liquid material, it is more preferable to set it as 0.05-5 weight%.

(6) Water The metal-polishing liquid material of the present invention may contain water. The amount of water to be contained can be appropriately determined according to the other components, the solubility in water, and the like, but is usually 50 to 98% by weight. The water content of the present invention is preferably 70 to 90% by weight. For example, when a component containing moisture is used in advance, such as when hydrogen peroxide is used as the oxidizing agent, the moisture content of the metal polishing material containing the moisture-containing component is 75 to 85% by weight. More preferably, the water content of the metal-polishing liquid material not containing the water-containing component is more preferably 80 to 90% by weight.

B. Method for Producing Metal Polishing Liquid The metal polishing liquid of the present invention is prepared by diluting the metal polishing liquid material of the present invention with a diluent. The concentration (composition ratio) of each component in the metal polishing liquid material depends on the composition and addition amount of the diluent added at the time of use and the concentration (composition ratio) of each component in the prepared metal polishing liquid. Determined.

  When water is used as the diluent, the metal polishing liquid material has the same composition and composition ratio as the components other than water of the metal polishing liquid, and the water content is reduced to a high concentration state. If it does in this way, the polishing liquid for metals of a desired composition can be obtained by adding water in the case of dilution.

  When an aqueous solution is used as the diluent, it is desirable to use an aqueous solution containing at least one of an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, and a solubilizing agent for the protective film forming agent. In this case, a metal-polishing liquid material containing at least one component selected from the group consisting of an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, and a solubilizing agent for the protective film forming agent is used. The metal polishing liquid of the present invention is prepared by diluting with a diluting aqueous solution that is an aqueous solution of at least one component. At this time, a desired component can be further added.

  Thus, when using the aqueous solution for dilution, each component density | concentration of metal polishing liquid material mixes the metal polishing liquid material and the aqueous solution for dilution (and the additive added as needed), As a result, It is determined so that a metal polishing liquid having a composition and concentration can be obtained. By doing so, components that are difficult to dissolve can be blended in the form of an aqueous solution, so that the concentration of the metal polishing liquid material can be made higher. For this purpose, the aqueous solution preferably contains a protective film forming agent and a solubilizing agent having low solubility.

  When the metal polishing liquid material is composed of two or more components (single substance or composition) that are not mixed with each other, the order of mixing these components and the diluent is particularly limited. Rather, it can be appropriately determined according to the solubility of each component, the liquid temperature at the time of dissolution, etc., for example, a diluent is added to one or a plurality of components, and this is further mixed with another component. Any method can be used, such as mixing, mixing the components first, then adding a diluent to the components, mixing the components in advance by adding a diluent, and mixing them. Can be used.

  Specifically, for example, a metal polishing comprising a first component A made of an oxidizing agent and a second component B made of a metal oxide solubilizer, a protective film forming agent, a solubilizing agent, and water. In the case of using a liquid material, the following methods (1) to (5) are listed as methods for producing a metal polishing liquid (that is, a method for diluting the polishing liquid material). Also good.

(1) Method of mixing component A and component B and diluting the mixture with a diluent (2) Method of diluting component A with a diluent and mixing this with component B (3) Method of diluting component B with diluent and mixing it with component A (4) Component A and component B are diluted with a diluent, respectively, and component A after dilution and configuration after dilution Method of mixing element B (5) Method of mixing component A, component B and diluent substantially simultaneously In addition, low-solubility components such as protective film forming agents are divided into two or more components. In some cases, it can be dissolved in each component liquid without increasing the amount of the solvent (usually water).

  For example, when the protective film forming agent is divided into two components, the metal abrasive material is composed of a first component A comprising an oxidizing agent, a protective film forming agent and a solubilizing agent, a metal oxide dissolving agent, and a protective film. It is comprised with the 2nd component B which consists of a forming agent, a solubilizing agent, and water.

  Further, when the protective film forming agent is divided into three components, the metal polishing liquid material is, for example, from the first component A composed of the protective film forming agent and the oxidizing agent, the protective film forming agent, and the metal oxide dissolving agent. The second constituent element B, the protective film forming agent, and the third constituent element C consisting of a solubilizing agent can also be used.

  As described above, when the metal polishing liquid material is divided into a plurality of components, a large amount of the protective film forming agent having a low solubility in the solvent (usually water) can be obtained by dividing the same compounding component into a plurality of components. Since it can melt | dissolve, the polishing liquid material for metals of high concentration can be obtained. Here, the number of components for distributing the components is not limited to 2 or 3 in the above example, and can be appropriately determined as necessary.

  The present invention is not limited to the above example, and can be appropriately employed as long as each component of the metal polishing liquid is divided into a high-concentration composition and diluted.

  In the metal polishing slurry of the present invention, hydrogen peroxide, which is suitable as an oxidizing agent, starts to decompose when the temperature is higher than 40 ° C. Therefore, when stored or used above this temperature, the oxidizing agent concentration changes. May adversely affect the polishing rate. For this reason, it is desirable that the oxidizing agent and the mixture containing it be 40 ° C. or lower.

  However, since the solubility is generally higher when the liquid temperature is higher, it is desirable to increase the liquid temperature from the viewpoint of obtaining a high-concentration solution for a low-solubility compound solution.

  Therefore, in the method for producing a metal polishing slurry of the present invention, the first component including the oxidizing agent is set to 40 ° C. or lower, the other components are heated in the range of room temperature to 100 ° C., and the first When mixing a component with another component or diluent, it is preferable that the liquid temperature after mixing be 40 ° C. or lower.

  In addition, when a low-solubility compound is heated and dissolved, a part of the dissolved component may be precipitated when the temperature is lowered. In such a case, it may be heated and dissolved again at the time of use.

C. Polishing Method Next, the polishing method of the present invention will be described.

  In the polishing method of the present invention, at least a part of the metal film is removed by the step of polishing the metal film using the metal-polishing liquid of the present invention. The polishing method of the present invention is a metal film comprising a laminated film including at least one metal layer selected from copper and copper alloy, copper oxide and copper alloy oxide (hereinafter simply referred to as copper alloy). Especially suitable for polishing.

  When the surface of a substrate in which a metal film containing copper or a copper alloy (copper / chromium, etc.) is formed and filled on a substrate having a recess having a desired pattern on the surface is subjected to CMP using the metal polishing slurry of the present invention, The convex metal film is selectively subjected to CMP, leaving the metal film in the concave, and a desired conductor pattern is obtained.

  In addition, the present inventors have found that a preferable planarization effect can be obtained if the etching rate in the polishing step can be suppressed to 10 nm / min or less. If the decrease in the CMP rate accompanying the decrease in the etching rate is acceptable, the lower etching rate is desirable, and if it can be suppressed to 5 nm / min or less, for example, about 50% excess CMP (to remove the metal film by CMP). Even if the CMP is performed 1.5 times as long as necessary, dishing does not become a problem. Furthermore, if the etching rate can be suppressed to 1 nm / min or less, dishing does not cause a problem even if 100% or more of excess CMP is performed.

  Here, the etching rate is determined by immersing a substrate to be polished (a substrate having a metal film formed and filled on a substrate having a recess on the surface) in a metal polishing liquid, and stirring at 100 rpm at room temperature (25 ° C.). It is the etching rate of the metal film, and is obtained by converting the metal film thickness difference from the electric resistance value.

  In the polishing method using the metal polishing liquid of the present invention, the metal polishing liquid of the present invention is supplied to the polishing pad on the polishing surface plate and brought into contact with the surface to be polished to cause the surface to be polished and the polishing pad to move relative to each other. To be polished.

  As an apparatus for polishing, there is a general polishing apparatus having a polishing surface plate with a holder for holding a semiconductor substrate having a surface to be polished and a polishing pad attached (a motor etc. capable of changing the number of rotations is attached). Can be used. In addition, a general nonwoven fabric, a polyurethane foam, a porous fluororesin, etc. can be used for a polishing pad, and there is no restriction | limiting in particular.

The polishing conditions are not limited, but the rotation speed of the polishing platen is preferably a low rotation of 200 rpm or less so that the substrate does not jump out. Moreover, it is preferable that the pressing pressure to the polishing pad of a to-be-polished object (semiconductor substrate etc.) which has a to-be-polished surface (film to be polished) is 9.8-98.1 kPa (100-1000 gf / cm < ² >), In order to satisfy the uniformity of the polishing rate within the wafer surface and the flatness of the pattern, it is more preferably 9.8 to 49.0 kPa (100 to 500 gf / cm ² ).

  During polishing, the metal polishing liquid is continuously supplied to the polishing pad by a pump or the like. Although there is no restriction | limiting in this supply amount, it is preferable that the surface of a polishing pad is always covered with polishing liquid.

  The semiconductor substrate after polishing is preferably washed in running water and then dried after removing water droplets adhering to the semiconductor substrate using a spin dryer or the like.

  In the polishing method of the present invention, the metal polishing liquid of the present invention is prepared in advance and is put in a tank (polishing liquid reservoir) of the polishing apparatus, or the metal polishing liquid is prepared in the tank and polished. You may make it use for the supply to a pad. Moreover, the polishing liquid material for metal of this invention and a diluent are put into a polisher, and it mixes in a polisher (including the inside of piping), and polish of this invention You may make it supply a polishing pad, preparing a liquid. In any case, the above-described method for producing a metal polishing liquid of the present invention can be applied to the preparation of the metal polishing liquid.

  As a method of preparing a metal polishing liquid in a polishing apparatus using a metal polishing liquid material, for example, a pipe for supplying a metal polishing liquid material and a pipe for supplying a diluent are joined in the middle. There is a method of mixing each solution flowing in a pipe and supplying a metal polishing liquid diluted thereby to the polishing pad.

  For mixing, a method in which liquids collide with each other through a narrow passage under pressure, a method in which a filler such as a glass tube is filled in a pipe, a flow of liquid is separated and separated, and a process in which pipes are repeatedly combined, A conventionally performed method such as a method of providing blades that rotate by power can be employed.

  In addition, as a method for preparing the metal polishing liquid in the pipe, a pipe for supplying the metal polishing liquid material and a pipe for supplying the diluent are independently provided, and a predetermined amount of liquid is supplied from each to the polishing pad, There is also a method of mixing both liquids by relative movement of a polishing pad and a surface to be polished.

  In addition, in the method of mixing by these pipes, when the metal polishing liquid material is composed of a plurality of components, by providing a pipe for each component, the metal polishing liquid can be provided in the same manner as in the above methods. Can be prepared.

  In the polishing method of the present invention, the component containing the oxidizing agent of the metal polishing liquid material is maintained at 40 ° C. or lower, the other components are heated in the range of room temperature to 100 ° C., and these components are After mixing, the mixture can also be kept at 40 ° C. or lower. Since solubility becomes high when temperature is high, it is a preferable method for increasing the solubility of components having low solubility in the metal polishing slurry.

  In the case of using a component in which components (other than the oxidizing agent) are heated and dissolved in the range from room temperature to 100 ° C., because the components are precipitated in the solution when the temperature is lowered, so Needs to be heated in advance to dissolve the precipitate. For this purpose, there are provided means for sending a heated and dissolved component (mixed liquid), and means for stirring the liquid containing the precipitate and feeding and heating the pipe to dissolve it. Can be dealt with.

  In addition, when the temperature of the component containing an oxidizing agent becomes higher than 40 degreeC by mixing the heated component, there exists a possibility that an oxidizing agent may decompose | disassemble. Therefore, the temperature of the component to be heated, the temperature of the component containing the oxidant to be cooled, and the mixing ratio thereof are preferably determined so that the temperature after mixing is 40 ° C. or less.

  Hereinafter, the present invention will be described specifically by way of examples. The present invention is not limited to these examples. The polishing conditions are as follows.

(Polishing conditions)
The polishing substrate and the substrate were rotated while supplying the metal polishing liquid to the polishing pad on the polishing surface plate in the polishing apparatus using a metering pump, and the substrate to be polished was polished under the following polishing conditions. The polishing liquid was prepared in advance before polishing and held in one container (polishing liquid reservoir) and supplied to a metering pump unless otherwise specified.

Substrate: Silicon substrate polishing pad with a 1 μm thick copper film: IC1000 (trade name, manufactured by Rodel)
Polishing pressure: 20.6 kPa (210 g / cm ² )
Relative speed between substrate and polishing surface plate: 36 m / min
(Abrasive product evaluation items)
CMP rate: The difference in film thickness of the copper film before and after CMP was calculated from the electrical resistance value.

Etching rate: The copper layer thickness difference before and after immersion in a metal polishing slurry stirred at 25 ° C. and 100 rpm was calculated from the electrical resistance value.

  Further, in order to evaluate actual CMP characteristics, a groove having a depth of 0.5 μm is formed in an insulating layer, a copper film is formed by a known sputtering method, and a silicon substrate embedded by a known heat treatment is used as a base. , CMP was performed. The presence or absence of erosion and polishing scratches was confirmed by visual inspection of the substrate after CMP, observation with an optical microscope, and observation with an electron microscope.

(change over time)
Immediately after preparing the metal abrasive material, a metal abrasive was prepared using it, and after 20 days had elapsed after preparing the metal abrasive material, a metal abrasive was prepared using it. In each case, CMP was performed using the respective metal polishing agents under the above-described conditions, and the CMP rate and the etching rate were measured to confirm whether there was a difference between the two.

Example 1
(1) Preparation of metal polishing liquid material First, 61.5 parts by weight of water was added to 1.5 parts by weight of DL-malic acid (reagent special grade), which is a metal oxide solubilizer, and dissolved to obtain Solution A. . Next, 2 parts by weight of benzotriazole, which is a protective film forming agent, was dissolved in 5 parts by weight of ethanol, which is a good solvent for the protective film forming agent, to obtain a solution B. Finally, the solution B was added to the solution A and mixed to obtain a 10-fold concentrated liquid for metal polishing liquid, which is a metal polishing liquid material.

  In addition, solid precipitation was not seen even if the obtained concentrate was preserve | saved at 0 degreeC.

(2) Preparation of metal polishing liquid To 7 parts by weight of this metal polishing liquid 10-fold concentrated solution, 33.2 parts by weight of hydrogen peroxide (reagent special grade, 30% aqueous solution) as an oxidizing agent was added, and further a diluent. As a result, 63 parts by weight of water was added for dilution to obtain a metal polishing slurry.

(3) CMP test Using the obtained metal polishing liquid, CMP was performed under the above-described polishing conditions. The CMP rate was 129 nm / min and the etching rate was 0.5 nm / min. There was no difference between the CMP rate and the etching rate due to the change of the polishing liquid material over time. Moreover, neither erosion nor polishing scratches were observed.

Example 2
(1) Preparation of Metal Polishing Liquid Material First, 61 parts by weight of water was added to 1.5 parts by weight of DL-malic acid (special reagent grade) and dissolved to obtain Solution A. Next, 2 parts by weight of benzotriazole, which is a protective film forming agent, and 0.5 parts by weight of ammonium polyacrylate are dissolved in 5 parts by weight of methanol, which is a good solvent for these protective film forming agents. Obtained. Finally, the solution B was added to the solution A to obtain a metal polishing liquid 10-fold concentrated liquid that is a metal polishing liquid material.

(2) Preparation of Metal Polishing Liquid After diluting 7 parts by weight of the obtained metal polishing liquid 10-fold concentrated solution with 63 parts by weight of water as a diluent, hydrogen peroxide solution (reagent special grade) as an oxidizing agent was further added. , 30% aqueous solution) 33.2 parts by weight was added to obtain a metal polishing slurry.

(3) CMP test Using the obtained metal polishing liquid, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 179 nm / min and the etching rate was 0.5 nm / min. In addition, there was no difference between the CMP rate and the etching rate due to the aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 3
(1) Preparation of metal polishing liquid material 58.7 parts by weight of water was added to 1.5 parts by weight of DL-malic acid (special reagent grade) and 0.3 parts by weight of polyvinyl alcohol as a protective film forming agent. Solution A was obtained by dissolution. Next, 2.5 parts by weight of tolyltriazole as a protective film forming agent was dissolved in 7 parts by weight of acetone to obtain a solution B. Finally, the solution B was added to the solution A to obtain a 10-fold concentrated metal polishing liquid.

(2) Preparation of Metal Polishing Liquid After diluting by adding 63 parts by weight of water as a diluent to 7 parts by weight of the obtained metal polishing liquid 10-fold concentrated liquid, hydrogen peroxide solution as an oxidizing agent was added thereto. (Special reagent grade, 30% aqueous solution) 33.2 parts by weight were added to obtain a metal polishing slurry.

(3) CMP test Using the obtained metal polishing liquid, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 170 nm / min and the etching rate was 0.4 nm / min. There was no difference in the CMP rate and the etching rate due to the change of the metal polishing liquid material over time. Moreover, neither erosion nor polishing scratches were observed.

Example 4
(1) Preparation of metal polishing liquid material 0.06 parts by weight of naphthotriazole, which is a protective film forming agent, was dissolved in 0.6 parts by weight of methyl ethyl ketone, which is a good solvent for the protective film forming agent, to obtain a solution A. . Further, 10 parts by weight of potassium periodate as an oxidizing agent was dissolved in 20 parts by weight of water to obtain a solution B. Next, the solution B was added to the solution A, and the solution C (1st component) was obtained.

  On the other hand, 30 parts by weight of water was added to 0.05 part by weight of DL-tartaric acid (reagent special grade), which is a metal oxide solubilizer, and dissolved to obtain Solution D. Further, 0.01 part by weight of naphthotriazole was dissolved in 0.1 part by weight of methyl ethyl ketone to obtain a solution E, and then this solution E was added to the solution D to obtain a solution F (second component).

  Subsequently, 40 parts by weight of water was added to 0.1 part by weight of DL-tartaric acid and dissolved to obtain a solution G (an aqueous solution for dilution) as a diluent.

  Thus, solutions C, F, and G, which are metal polishing liquid materials, were obtained.

(2) Preparation of metal polishing liquid The obtained solution C, solution F, and solution G were mixed at a weight ratio of 3/3/4 to obtain a metal polishing liquid.

(3) CMP test Using the obtained metal polishing liquid, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 126 nm / min and the etching rate was 0.4 nm / min. In addition, there was no difference between the CMP rate and the etching rate due to the aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 5
(1) Preparation of metal polishing liquid material To 0.15 parts by weight of DL-malic acid (special grade reagent), 0.4 part by weight of polyacrylamide as a protective film forming agent and 50 parts by weight of water were added and dissolved. Solution A was obtained. Next, 0.2 part by weight of benzotriazole was dissolved in 0.7 part by weight of ethylene glycol to obtain a solution B. Finally, the solution B was added to the solution A heated to 45 ° C. while maintaining the temperature at 45 ° C. to obtain a solution C which is a metal polishing liquid material. Solution C was also held at 45 ° C.

(2) Preparation of Metal Polishing Liquid After diluting this 45 ° C. solution C with 20 parts by weight of water heated to 45 ° C., 20 ° C. hydrogen peroxide solution (special grade reagent, 30% aqueous solution) 33 2 parts by weight were poured into a metal polishing slurry. The obtained metal polishing slurry was at 36 ° C.

(3) CMP test Using the above metal polishing liquid, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 167 nm / min and the etching rate was 0.3 nm / min. In addition, there was no difference between the CMP rate and the etching rate due to the aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 6
(1) Preparation of Metal Polishing Liquid Material A metal polishing liquid material was prepared in the same manner as in Example 1. However, benzotriazole was put in a mortar in advance and then ground with a pestle for 5 minutes before dissolution. As a result of observing the ground benzotriazole with an optical microscope, the average particle size was 80 μm. By using benzotriazole having a particle size reduced by this pretreatment, in this example, the time required for completely dissolving benzotriazole in ethanol was shortened from 5 minutes to 2 minutes.

(2) Preparation of metal polishing liquid and CMP test Using the above metal polishing liquid material, a metal polishing liquid was prepared in the same manner as in Example 1, and CMP was performed under the same conditions as in Example 1. gave. As a result, the CMP rate was 130 nm / min and the etching rate was 0.5 nm / min, both good, and no difference in the CMP rate and the etching rate due to aging of the metal polishing liquid material was observed. Moreover, neither erosion nor polishing scratches were observed.

Example 7
To the metal polishing liquid of Example 2, 1 part by weight of colloidal silica having an average particle size of 100 nm was further added as abrasive grains and dispersed to obtain a metal polishing liquid. Using this, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 252 nm / min, the etching rate was 0.6 nm / min, and the change in the polishing material for metal over time was good. No difference in CMP rate and etching rate was observed. Moreover, neither erosion nor polishing scratches were observed.

Example 8
In the same manner as in Example 2, a metal polishing liquid was prepared. However, the metal polishing liquid material was prepared by adding Solution B and 10 parts by weight of colloidal silica having an average particle size of 48 nm to Solution A.

  Using this, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 250 nm / min, the etching rate was 0.5 nm / min. No difference in CMP rate and etching rate was observed. Moreover, neither erosion nor polishing scratches were observed.

Example 9
Using the metal polishing slurry of Example 1, CMP was performed under the same conditions as in Example 1. However, the metal polishing liquid was prepared by mixing in a pipe. That is, a diluted solution obtained by adding 63 parts by weight of water to 7 parts by weight of a 10-fold concentrated metal polishing solution and a hydrogen peroxide solution (special grade, 30% aqueous solution) are put in separate containers, respectively. Inside the pipe filled with a lot of glass tubes with a length of 3 mm, each of which was sent from the container with a metering pump and merged at a supply rate ratio (volume ratio) of diluent / hydrogen peroxide solution = 7/3 Was passed through and then supplied to a polishing pad inside the apparatus for polishing.

  As a result, the CMP rate was good at 129 nm / min and the etching rate was both 0.5 nm / min, and no difference was observed between the CMP rate and the etching rate due to the aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 10
CMP was performed in the same manner as in Example 1 using the metal polishing slurry of Example 4. However, the metal polishing liquid was prepared by mixing in a pipe. That is, the solution C and the mixed solution of the solution F and the solution G are put in separate containers, and the solution is separately sent from each container with a metering pump, so that solution C / (solution F + solution G) = 3/7. Were fed together at a supply speed ratio (volume ratio) and supplied to a polishing pad inside the apparatus for polishing.

  As a result, the CMP rate was 125 nm / min, the etching rate was 0.4 nm / min, both of which were good, and there was no difference in the CMP rate and the etching rate due to the aging of the metal polishing liquid material. . Moreover, neither erosion nor polishing scratches were observed.

Example 11
A metal polishing liquid was prepared in the same manner as in Example 1 except that the amount of ethanol added was increased from 5 parts by weight to 50 parts by weight in the preparation of the metal polishing liquid 10-fold concentrated liquid, and CMP was performed using this. As a result, the etching rate was 0.5 nm / min, and the CMP rate was 62 nm / min.

Example 12
(1) Preparation of Metal Polishing Liquid Material First, 66 parts by weight of water is added to 2 parts by weight of benzotriazole, which is a protective film forming agent, and 0.4 parts by weight of polyoxyethylene (10) glycol, which is a surfactant. In addition, the mixture was stirred and dissolved in a 40 ° C. hot water bath with a stirring blade. To this solution, 1.5 parts by weight of DL-malic acid (reagent special grade), which is a metal oxide solubilizer, was added and dissolved to obtain a 10-fold concentrated metal polishing liquid, which is a metal polishing liquid material.

  In addition, solid precipitation was not seen even if the obtained concentrate was preserve | saved at 0 degreeC.

(2) Preparation of Metal Polishing Liquid 7 parts by weight of this metal polishing agent 10-fold concentrated solution was diluted by adding 63 parts by weight of water as a diluent, and hydrogen peroxide (reagent special grade, 30 as an oxidizing agent). % Aqueous solution) 33.2 parts by weight was added to obtain a metal polishing slurry.

(3) CMP test Using the obtained metal polishing slurry, CMP was performed in the same manner as in Example 1. As a result, the CMP rate was 187 nm / min and the etching rate was 0.7 nm / min. In addition, there was no difference between the CMP rate and the etching rate due to the aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 13
66 parts by weight of water is added to 2 parts by weight of tolyltriazole, which is a protective film forming agent, and subsequently, 0.4 parts by weight of polyoxyethylene (9) octylphenyl ether, which is also a protective film forming agent, is added. The mixture was stirred and dissolved in a hot water bath with a stirring blade. To this solution, 1.5 parts by weight of DL-tartaric acid (special reagent grade) was further added and dissolved to obtain a 10-fold concentrated metal polishing liquid, which is a metal polishing liquid material.

(2) Preparation of Metal Polishing Liquid To 7 parts by weight of the obtained metal polishing liquid 10-fold concentrated solution, 63 parts by weight of water was added for dilution, and hydrogen peroxide solution (special grade, 30% aqueous solution) 33 was added thereto. .2 parts by weight was added to obtain a metal polishing slurry.

(3) CMP test Using this metal polishing liquid, CMP was performed in the same manner as in Example 1. As a result, the CMP rate was 186 nm / min, the etching rate was 0.3 nm / min, and both were good. There was no difference between the CMP rate and the etching rate due to the aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 14
(1) Preparation of metal polishing liquid material 0.05 part by weight of benzotriazole as a protective film forming agent, 0.1 part by weight of butylammonium sulfate as a surfactant, and 10 parts by weight of potassium periodate as an oxidizing agent Part A was added to 20 parts by weight of water, and dissolved by stirring with a stirring blade in a hot water bath at 40 ° C. to obtain a solution A.

  Next, 30 parts by weight of water is added to 0.05 part by weight of DL-tartaric acid (reagent special grade) which is a metal oxide solubilizer, and dissolved therein. Then, 0.1 part by weight of butylammonium sulfate was added and dissolved by stirring with a stirring blade in a hot water bath at 40 ° C. to obtain a solution B.

  Thus, Solution A and Solution B, which are metal abrasive materials, were obtained. Further, 40 parts by weight of water was added to 0.1 part by weight of DL-tartaric acid and dissolved to obtain an aqueous solution for dilution.

(2) Preparation of metal abrasive | polishing agent The obtained solution A, solution B, and aqueous solution for dilution were mixed by weight ratio 3/3/4, and the metal polishing slurry was obtained.

(3) CMP test Using this metal polishing solution, CMP was performed in the same manner as in Example 1. As a result, the CMP rate was 126 nm / min, the etching rate was 0.4 nm / min, and both were good. There was no difference between the CMP rate and the etching rate due to aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 15
(1) Preparation of Metal Polishing Liquid Material Add benzotriazole 0 to 0.15 parts by weight of DL-malic acid (special reagent grade) by adding 50 parts by weight of water and keep the resulting solution at 45 ° C. .2 parts by weight and 0.7 parts by weight of succinamide as a surfactant were added and dissolved to obtain a solution A.

(2) Preparation of Metal Polishing Liquid After diluting this 45 ° C. solution A with 20 parts by weight of water heated to 45 ° C., 20% hydrogen peroxide (reagent special grade, 30 % Aqueous solution) 33.2 parts by weight was poured into a metal polishing slurry. The resulting polishing liquid was 36 ° C.

(3) CMP test Using this metal polishing liquid, CMP was performed in the same manner as in Example 1. As a result, the CMP rate was 127 nm / min and the etching rate was 0.3 nm / min. There was no difference between the CMP rate and the etching rate due to aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 16
(1) Preparation of metal polishing liquid material A metal polishing liquid material was prepared in the same manner as in Example 12. However, in this example, benzotriazole was pretreated in the same manner as in Example 6 so that the average particle size was 80 μm. This shortened the time required to completely dissolve benzotriazole from 15 minutes to 5 minutes.

(2) Preparation of metal polishing liquid and CMP test Using the above metal polishing liquid material, a metal polishing liquid was prepared in the same manner as in Example 12, and CMP was performed in the same manner as in Example 1 using this. It was. As a result, the CMP rate was 185 nm / min and the etching rate was 0.6 nm / min, both of which were good, and there was no difference between the CMP rate and the etching rate due to aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Example 17
To the metal polishing slurry of Example 12, 1 part by weight of colloidal silica having an average particle size of 100 nm was further added and dispersed as abrasive grains to obtain a metal polishing slurry. Using this, CMP was performed in the same manner as in Example 1. As a result, the CMP rate was 250 nm / min and the etching rate was 0.6 nm / min. There was no difference between the CMP rate and the etching rate. Moreover, neither erosion nor polishing scratches were observed.

Example 18
A metal polishing slurry was prepared in the same manner as in Example 12. However, the metal polishing liquid material was prepared by adding 10 parts by weight of colloidal silica having an average particle diameter of 48 nm to the metal polishing liquid 10-fold concentrated liquid of Example 12.

  Using this, CMP was performed under the same conditions as in Example 1. As a result, the CMP rate was 244 nm / min, the etching rate was 0.6 nm / min, and the change over time of the metal polishing liquid material No difference in CMP rate and etching rate was observed. Moreover, neither erosion nor polishing scratches were observed.

Example 19
Using the metal polishing slurry of Example 12, CMP was performed under the same conditions as in Example 1. However, the metal polishing liquid was prepared by mixing in a pipe. That is, a diluted solution obtained by adding 63 parts by weight of water to 7 parts by weight of the 10-fold concentrated metal polishing liquid and 33.2 parts by weight of hydrogen peroxide (special grade, 30% aqueous solution) are separately used. Place in a container, send the liquid separately from each container with a metering pump, merge at a supply rate ratio (volume ratio) of diluting solution / hydrogen peroxide solution = 7/3, and install a 3 mm long glass tube inside After passing through a large number of filled pipes, it was supplied to a polishing pad inside the apparatus for polishing.

  As a result, the CMP rate was 177 nm / min, the etching rate was 0.5 nm / min, both good, and no difference in the CMP rate and the etching rate due to aging of the metal polishing liquid material was observed. Moreover, neither erosion nor polishing scratches were observed.

Example 20
CMP was performed in the same manner as in Example 1 using the metal polishing slurry of Example 14. However, the metal polishing liquid was prepared by mixing in a pipe. That is, the solution A, the solution B, and the mixed solution of the diluting aqueous solution are put in separate containers, and the solution is separately sent from each container with a metering pump, and solution A / (solution B + diluting aqueous solution) = 3 / 7 at a supply rate ratio (volume ratio) of / 7 and supplied to a polishing pad inside the apparatus for polishing.

  As a result, the CMP rate was 124 nm / min and the etching rate was 0.4 nm / min, both of which were good, and there was no difference between the CMP rate and the etching rate due to aging of the metal polishing liquid material. Moreover, neither erosion nor polishing scratches were observed.

Comparative Example 1
A 10-fold concentrated metal polishing liquid was prepared in the same manner as in Example 1 except that ethanol was not added. When this was stored refrigerated at 5 ° C., solids were precipitated, making it difficult to prepare and evaluate a metal polishing liquid as it was.

Comparative Example 2
Except not adding polyoxyethylene (10) glycol, it carried out similarly to Example 12, and prepared the polishing liquid 10 times concentrated liquid for metals. When this was stored refrigerated at 5 ° C., solids were precipitated, making it difficult to prepare and evaluate a metal polishing liquid as it was.

  The present invention provides a high-concentration metal polishing liquid material, and this high-concentration polishing liquid material is used for transportation and storage, and when actual polishing is performed, a diluent or the like is added thereto. In addition, the polishing liquid can be easily prepared. Therefore, according to the present invention, the manufacturing cost of the metal polishing liquid can be reduced, the number of the polishing liquid storage / transport containers used can be reduced, and the capacity of the storage place and the tank of the polishing apparatus can be reduced. In addition, a highly reliable embedded pattern of the metal film can be formed. Therefore, the present invention is particularly useful in the manufacture of semiconductor devices.

Claims (14)

A method for producing a metal polishing slurry comprising an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, a solubilizing agent for the protective film forming agent, and water,
A first component comprising an oxidant;
Polishing for metals including a mixing step of mixing a second component containing at least one component of a component group consisting of a metal oxide solubilizer, a protective film forming agent and a solubilizing agent for the protective film forming agent, and a diluent Liquid manufacturing method. The method for producing a metal polishing slurry according to claim 1, wherein the first component, the second component, and a diluent are mixed by any one of the following methods (1) to (5). .
(1) Method of mixing component A and component B and diluting the mixture with a diluent (2) Method of diluting component A with a diluent and mixing this with component B (3) Method of diluting component B with diluent and mixing it with component A (4) Component A and component B are diluted with a diluent, respectively, and component A after dilution and configuration after dilution Method of mixing component B (5) Method of mixing component A, component B and diluent almost simultaneously   The method for producing a metal polishing slurry according to claim 1 or 2, wherein the second component is diluted with the diluent and mixed with the first component.   The method for producing a metal polishing slurry according to claim 1, wherein the diluent is water or an aqueous solution for dilution.   The method for producing a metal-polishing liquid according to any one of claims 1 to 4, wherein the second component includes a protective film forming agent and a solubilizing agent.   The method for producing a metal polishing slurry according to claim 1, wherein the second component includes a metal oxide solubilizer, a protective film forming agent, and a solubilizing aid.   The solubilizer is at least one of ester, ether, polysaccharide, amino acid salt, polycarboxylic acid, polycarboxylate, vinyl polymer, sulfonic acid, sulfonate, and amide. The manufacturing method of the polishing liquid for metals in any one of these.   The method for producing a metal polishing slurry according to any one of claims 1 to 7, wherein the dissolution aid is a solvent having a solubility of the protective film forming agent of 25 g / L or more.   The method for producing a metal-polishing liquid according to any one of claims 1 to 8, wherein the dissolution aid is at least one of alcohol, ether, and ketone.   The method for producing a metal-polishing liquid according to claim 1, wherein in the mixing step, the first component is held at 40 ° C. or lower.   The metal polishing according to claim 1, wherein at least a part of the protective film forming agent is a solid having an average particle diameter of 100 μm or less and is dissolved or dispersed in the metal polishing liquid by the mixing step. Liquid manufacturing method.   The method for producing a metal-polishing liquid according to any one of claims 1 to 11, wherein a blending amount of the solvent is less than 50 g with respect to a total amount of 100 g of the first component and the second component.   The manufacturing method of the metal-polishing liquid in any one of Claims 1-12 including the process of further mixing an abrasive grain. A method of producing a metal polishing slurry comprising an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, a solubilizing agent for the protective film forming agent, and water,
A first component containing at least one component of a component group consisting of an oxidizing agent, a metal oxide solubilizer, a protective film forming agent, and a solubilizing agent for the protective film forming agent;
A second component comprising at least one component of the remaining components of the component group;
The manufacturing method of the polishing liquid for metals including the mixing process which mixes a diluent.