CN1952034A - Abrasive liquid for metal and abrasive method - Google Patents
Abrasive liquid for metal and abrasive method Download PDFInfo
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- CN1952034A CN1952034A CN 200610137146 CN200610137146A CN1952034A CN 1952034 A CN1952034 A CN 1952034A CN 200610137146 CN200610137146 CN 200610137146 CN 200610137146 A CN200610137146 A CN 200610137146A CN 1952034 A CN1952034 A CN 1952034A
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Abstract
An abrasive liquid for a metal comprising (1) an oxidizing agent for a metal, (2) a dissolving agent for an oxidized metal, (3) a first protecting film-forming agent such as an amino acid or an azole which adsorbs physically on the surface of the metal and/or forms a chemical bond, to thereby form a protecting film, (4) a second protecting film-forming agent such as polyacrylic acid, polyamido acid or a salt thereof which assists the first protecting film-forming agent in forming a protecting film and (5) water; and a method for polishing.
Description
The application be application number 200510068160.0, Augusts 31 in 1999 applying date day, be called: the dividing an application of the patent application of metal polishing slurry and Ginding process.And this application number is 200510068160.0 application is that application number 99812776.0, August 31 1999 applying date, invention and created name are: the dividing an application of the patent application of metal polishing slurry and Ginding process.
Technical field
The invention relates in the grinding in the distribution forming process of semiconductor device metal polishing slurry that is particularly suitable for using and Ginding process.
Background technology
In recent years, follow highly integrated, the high performance of semiconductor integrated circuit (below, be called LSI), developing new Micrometer-Nanometer Processing Technology.Cmp (below, be called CMP) method also is wherein a kind of, is in the LSI manufacturing processed, the particularly planarization of the interlayer dielectric in multilayer wired forming process, metallic plug form, imbed distribution form in the frequent technology of using.This technology, for example open in No. 4944836 communique of United States Patent (USP).
In addition, in order to make the LSI high performance, just attempting utilizing copper alloy recently as wiring material.But copper alloy is difficult to utilize in the formation of in the past aluminium alloy distribution the frequent dry corrosion method of using to carry out microfabrication.Therefore, the main employing being pre-formed accumulation copper alloy thin films on the insulating film of ditch imbedded, and utilizes CMP to remove ditch portion copper alloy thin films in addition, forms so-called Damascus wave pattern (damascen) method of imbedding distribution.This technology is for example opened in the flat 2-278822 communique open the spy.
The general method of the CMP of metal is that fixed abrasive pad is gone up on the grinding chassis (pressure nog plate) in circle, flood grinding pad with metal polishing slurry, compress the face of the metallic membrane that forms matrix, from its inside with the pressure that applies regulation (below, be called grinding pressure) state make and grind the chassis rotation, utilize the mechanical friction of the protuberance of lapping liquid and metallic membrane, remove the method for the metallic membrane of protuberance.
The metal polishing slurry that uses in CMP generally is made up of oxygenant and solid abrasive particles, as required, can also add oxidized metal dissolving agent, protective membrane formation agent.Be considered at first make the metallic film surface oxidation, utilize solid abrasive particles to grind off the fundamental mechanism of this zone of oxidation by oxidation.The zone of oxidation of the metallic surface of recess not too contacts grinding pad, does not reach the effect of utilizing solid abrasive particles to grind off, therefore along with the carrying out of CMP, removes the metal level of protuberance, makes the matrix surface planarization.About this details, described at the 3460-3464 page or leaf of Journal of eletrochemical society magazine the 138th volume No. 11 (distribution in 1991).
If utilize the particle of the metal oxide that solid abrasive particles grinds off to be dissolved in the lapping liquid, just increase the effect of utilizing solid abrasive particles to grind off by oxidized metal dissolving agent.But the zone of oxidation of the metallic film surface of recess is also dissolved (below, be called corrosion), when metallic film surface was exposed, because oxygenant makes the further oxidation of metallic film surface, and it was when carrying out repeatedly, also carried out the corrosion of the metallic membrane of recess, therefore the impaired worry of planarization effect has just been arranged.In order to prevent that the planarization effect from suffering damage, add protective membrane again and form agent.The effect balance that reaches oxidized metal dissolving agent and protective membrane formation agent is very important, and the particulate efficiency of the zone of oxidation that wish that the zone of oxidation of metallic film surface not too is corroded, grinds off grinding rate dissolved well, that utilize CMP is big.
Like this, form the effect that agent increases chemical reaction, when improving CMP speed (i.e. the grinding rate that produces by CMP), also obtain lowering the effect of the damage of the layer on surface of metal that causes by CMP by adding oxidized metal dissolving agent and protective membrane.
But, the metal polishing slurry that contains solid abrasive particles in the past in use, when utilizing the imbedding distribution and form of CMP, produce following problem: each takes place to identical corrosion in the surperficial middle body of the metal wiring that (1) is imbedded, and the low-lying phenomenon (hereinafter referred to as hollow bent) as the plate sample takes place; (2) take place to hinder (scratch) from the grinding of solid abrasive particles; (3) the clean process that is used to remove the solid abrasive particles that remains in the matrix surface after the grinding is complicated; And (4) result from the cost of solid abrasive particles itself or the cost raising of liquid waste disposal etc.
For suppress hollow bent or grind in the burn into of copper alloy form the high LSI distribution of reliability, advocate the method for using the metal polishing slurry that contains the oxidized metal dissolving agent that constitutes by Padil such as glycine or thionamic acid and benzotriazole (hereinafter referred to as BTA).This technology is for example opened in the flat 8-83780 communique on the books the spy.
But it is very high that the protective membrane of BTA forms effect, thereby corrosion speed not only, and grinding rate also reduces significantly.Therefore, wish in metal polishing slurry, to use and fully reduce corrosion speed, and do not reduce the protective membrane formation agent of CMP speed.
Disclosure of an invention
Fully reduce corrosion speed though the present invention provides, keep high CMP speed, and can form the metal polishing slurry of imbedding figure and the Ginding process of the high metallic membrane of reliability.
Metal polishing slurry of the present invention contains the oxygenant, oxidized metal dissolving agent, the 1st protective membrane that are useful on the oxidized metal and forms agent, forms agent different formation agent of the 2nd protective membrane and water with the 1st protective membrane.
It is that the protective membrane that forms protective membrane in the metallic surface forms agent that protective membrane forms agent.
Form agent as the 1st protective membrane, preferably be selected from nitrogenous compound and salt thereof such as ammonia, alkylamine, amino acid, imines, azoles, and at least a in mercaptan, glucose and the Mierocrystalline cellulose.It is the compound that forms protective membrane by absorption and/or the chemical key of formation at metallic film surface physics that these the 1st protective membranes form agent.
Form agent as the 2nd protective membrane, preferably be selected from least a in alcohol (compound that promptly has alcohol hydroxyl group), phenol (compound that promptly has the phenol hydroxyl), ester, ether, polyose, amino acid salts, poly carboxylic acid and salt, ethylene-based polymer, sulfonic acid and salt thereof, aromatic amine, acid amides, azo-compound and the molybdenum compound.These the 2nd protective membranes form agent, are that auxiliary the 1st protective membrane forms the compound that agent forms protective membrane.
Preferably be selected from least a in hydrogen peroxide, nitric acid, periodic acid potassium, hypochlorous acid and the ozone water as oxygenant.
As oxidized metal dissolving agent, preferably be selected from least a in organic acid, organic acid ammonium salt and the sulfuric acid.
The invention provides; when the 2nd protective membrane in not containing protective membrane formation agent forms agent; make corrosion speed be suppressed at the interpolation concentration A of necessary the 1st protective membrane formation of the effect agent below the 10nm/min with respect to performance; form agent by adding the 2nd protective membrane; the 1st protective membrane that contains the lower concentration that is lower than above-mentioned concentration forms agent, can show the metal polishing slurry that makes corrosion speed be suppressed at the following effect of 10nm/min.That is, in the case, it is in order to make corrosion speed be suppressed at the compound that necessary the 1st protective membrane below the 10nm/min forms the addition minimizing of agent that the 2nd protective membrane forms agent.
Ginding process of the present invention is a Ginding process of removing the metallic membrane on grinding charge surface in the metal polishing slurry of the invention described above by grinding.For the metallic membrane of removing object, copper, copper alloy, copper oxide, copper alloy oxide compound etc. are suitable.Therefore, the invention provides, use above-mentioned metal polishing slurry, contain the process of the metallic membrane that the stacked film that is selected from least a metal level in copper, copper alloy, copper oxide and the copper alloy oxide compound constitutes, remove the Ginding process of at least a portion of metallic membrane by grinding.
The invention provides, form agent, both kept CMP speed, fully reduce the lapping liquid of corrosion speed again and use the Ginding process of this lapping liquid by different the 1st and the 2nd protective membranes of combinatorial property.The 1st protective membrane forms agent can use the compound that generates chelating coordination thing with copper easily, for example uses ethylenediamine tetraacetic acid (EDTA), benzotriazole etc.It is extremely strong that their metal surface protection film forms effect, and for example in metal polishing slurry, if contain 0.5 weight % when above, much less tin-copper alloy film is corroded, and CMP also loses.
In contrast, the inventor finds, by using simultaneously and the 1st protective membrane forms the 2nd different protective membrane of agent and forms agent, reduces also to be suppressed to abundant low corrosion speed when annex solution that the 1st protective membrane forms agent is spent.And know, under the situation of using such lapping liquid,, also can obtain the not too low such optimal performance of CMP speed even corrosion speed is low.In addition also find, form agent and the 2nd protective membrane formation agent by using the 1st protective membrane simultaneously, do not contain in lapping liquid under the prerequisite of solid abrasive particles, the grinding under the CMP of practicality speed becomes possibility.Think that this is because with to grind off effect by in the past solid abrasive particles fricative opposite, found to be ground off by the fricative of grinding pad.
Knew already,,, just can obtain best planarization effect if can be suppressed at below the 10nm/min as the value of the corrosion speed that should suppress.If the reduction of CMP speed is the scope that can allow, that wish is the lower person of corrosion speed, if can be suppressed at below the 5nm/min, even for example carry out about 50% superfluous CMP (carry out CMP remove metallic membrane 1.5 times CMP between in case of necessity), hollow song also rests on unquestioned degree.And then if corrosion speed can be suppressed at below the 1nm/min, even carry out superfluous CMP more than 100%, hollow song does not become problem yet.
Corrosion speed in this manual, be that grinding charge is immersed in the lapping liquid, 25 ℃ of liquid temperature, the speed that the metallic membrane on the grinding charge surface when stirring velocity 100r/min stirs (copper film that utilizes sputter to form) is corroded, and be poor from the convert thickness of metal film obtain before and after the dipping of resistance value, the speed of obtaining divided by the thickness of metal film difference with dipping time.
In addition, CMP speed (being cmp speed) is at grinding pressure 210g/cm
2, grinding charge and grinding chassis the condition of 25 ℃ of speed of relative movement 36m/min, liquid temperature under, grind the metallic membrane (copper film that utilizes sputter to form) on grinding charge surface, poor from the convert thickness of metal film obtain before and after the dipping of resistance value, as to obtain divided by the film thickness difference with treatment time speed.
According to the present invention, with only different, do not relying under the strong mechanical friction condition that produces by solid abrasive particles with the lapping liquid of the 1st protective membrane formation agent, utilize friction can realize cmp planarizationization more than above-mentioned friction softish grinding pad.
And then, the invention provides, use metal polishing slurry of the present invention, grind on the surface has the matrix of recess and form the Ginding process that filling contains the matrix of copper, copper alloy metallic membranes such as (copper/chromium etc.).If use lapping liquid of the present invention that such matrix is carried out cmp (CMP), the metallic membrane of matrix protuberance at recess kish film, thereby obtains desirable conductor fig with regard to optionally carrying out cmp.In lapping liquid of the present invention, it is also passable not contain solid abrasive particles in fact, utilizes and carries out cmp more than the friction of solid abrasive particles softish mechanical grinding cushion, thereby make grinding hinder sharply attenuating.
Metal polishing slurry of the present invention forms agent, the formation agent of the 2nd protective membrane and water as necessary composition with oxygenant, oxidized metal dissolving agent, the 1st protective membrane.Can not contain solid abrasive particles in fact, also can use.
Then, the concrete example that is included in each composition in the metal polishing slurry of the present invention is described.
The oxygenant of metal can be enumerated hydrogen peroxide (H
2O
2), nitric acid, periodic acid potassium, hypochlorous acid, ozone water etc.At matrix is when comprising the silicon substrate of unicircuit usefulness element, the pollution that hope is not produced by basic metal, alkaline-earth metal, halogenide etc., thereby wish it is the oxygenant that does not contain nonvolatile component, but because the composition of ozone water is fierce over time, therefore in the oxygenant of enumerating more than, hydrogen peroxide preferably.But, be when not containing the glass substrate etc. of semiconductor element,, also to have no relations even contain the oxygenant of nonvolatile component at the matrix that uses object.
Oxidized metal dissolving agent wishes it is water miscible oxidized metal dissolving agent.In the agent of water soluble oxidized dissolving metal, can enumerate formic acid, acetate, propionic acid, butyric acid, valeric acid, 2-Methyl Butyric Acid, n-caproic acid, 3, organic acids such as 3-acid dimethyl, 2 Ethylbutanoic acid, 4-methylvaleric acid, positive enanthic acid, 2 methyl caproic acid, n-caprylic acid, 2 ethyl hexanoic acid, phenylformic acid, oxyacetic acid, Whitfield's ointment, R-Glyceric acid, oxalic acid, propanedioic acid, succsinic acid, pentanedioic acid, hexanodioic acid, pimelic acid, toxilic acid, phthalic acid, oxysuccinic acid, tartrate, citric acid, ammonium salt classes such as these organic acid ammonium salts or ammonium persulphate, ammonium nitrate, ammonium chloride; Mineral acid such as sulfuric acid, chromic acid, and ammino compound etc.They can use separately, also can make up any use.
For the stacked film that contains the metal level that is made of copper, copper alloy, copper oxide and/or copper alloy oxide compound, wherein, formic acid, propanedioic acid, oxysuccinic acid, tartrate, citric acid are suitable.These acid are preferred obtaining forming on the balance of agent with the described later the 1st and the 2nd protective membrane.Especially, with regard to oxysuccinic acid, tartrate, citric acid, both keeping practical CMP speed, it is preferred can suppressing the corrosion speed aspect again effectively.
Form agent as the 1st protective membrane, can enumerate ammonia; The amine of alkylamines such as dimethylamine, Trimethylamine 99, triethylamine, propylene diamine or ethylenediamine tetraacetic acid (EDTA) (being designated hereinafter simply as EDTA), Thiocarb and chitosan etc.; Padil; the L-L-Ala; Beta-alanine; the L-2-aminobutyric acid; the L-norvaline; the L-Xie Ansuan; the L-leucine; the L-nor-leucine; the L-Isoleucine; the other leucine of L-; the L-phenylalanine; the L-proline(Pro); sarkosine; the L-ornithine; L-Methionin; taurine; the L-Serine; the L-Threonine; the L-allothreonine; the L-homoserine; L-tyrosine; 3; 5-two iodo-L-tyrosine; β-(3, the 4-dihydroxyphenyl)-L-L-Ala; the L-tyrotoxin; 4-hydroxyl-L-proline(Pro); the L-halfcystine; the L-methionine(Met); the L-ethionine; the L-L-lanthionine; L-cystathionine; the L-Gelucystine; the L-cysteic acid; the L-aspartic acid; L-L-glutamic acid; S-(carboxymethyl)-L-halfcystine; the 4-aminobutyric acid; the L-asparagine; L-glutaminate; P-165; the L-arginine; the L-canavanine; the L-citrulline; δ-hydroxyl-L-Methionin; creatine; the L-kynurenine; the L-Histidine; 1-methyl-L-Histidine; 3-methyl-L-Histidine; ergothioneine; the L-tryptophane; sanarnycin
1, amino acid such as A Baan acid (ア パ ミ Application), angiotonin I, angiotensin II and anti-papain; Dithizone, diquinolyl (2,2 '-two quinoline), new diquinolyl (2,9-dimethyl-1, the 10-phenanthroline), crust rope diquinolyl (2,9-dimethyl-bathophenanthroline) and ball psytomin (キ ユ ペ ラ ゾ Application) imines such as (bicyclohexanone oxalyl hydrazones); Benzimidazolyl-2 radicals-mercaptan, 2-[2-(benzothiazolyl)] propane thioic acid, 2-[2-(benzothiazolyl)] Thiobutyric acid, 2-mercaptobenzothiazole, 1,2, the 3-triazole, 1,2, the 4-triazole, 3-amino-1H-1,2, the 4-triazole, benzotriazole, I-hydroxybenzotriazole, 1-dihydroxypropyl benzotriazole, 2,3-dicarboxyl propyl group benzotriazole, the 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole, 4-methoxycarbonyl-1H-benzotriazole, 4-butoxy-1H-benzotriazole, 4-carbonyl octyloxy-1H-benzotriazole, 5-hexyl benzotriazole, N-(1,2,3-benzotriazole quinoline base-1-methyl)-N-(1,2,4-triazoline base-1-methyl)-2 ethyl hexylamine, tolytriazole, aphthotriazoles, azoles such as two [(1-benzotriazole quinoline base) methyl] phosphonic acids; The ninth of the ten Heavenly Stems mercaptan such as mercaptan, dodecyl mercaptans, triazine thiol, triazine two mercaptan, triazine three mercaptan; And carbohydrate such as glucose, Mierocrystalline cellulose.They can use separately, also can appropriate combination use.
Wherein, at high CMP speed and low corrosion speed and cubic plane, be good with chitosan, ethylenediamine tetraacetic acid (EDTA), L-tryptophane, ball psytomin (キ ユ ペ ラ ゾ Application), triazine two mercaptan, benzotriazole, 4-hydroxybenzotriazole, 4-carboxyl-1H-benzotriazole butyl ester, tolytriazole and aphthotriazoles.Especially, benzotriazole and derivative the best thereof.For benzotriazole derivatives, can enumerate above-mentioned azoles etc.
Form agent as the 2nd protective membrane, can enumerate the 1-propyl alcohol, the 2-propyl alcohol, 2-propylidene-1-alcohol, vinyl carbinol, ethylidene cyanhydrin, the 1-butanols, the 2-butanols, (S)-(+)-the 2-butanols, 2-methyl isophthalic acid-propyl alcohol, the trimethyl carbinol, perfluor-trimethyl carbinol, crotyl alcohol, the 1-amylalcohol, 2,2-dimethyl-1-propyl alcohol, 2-methyl-2-butanols, 3-methyl isophthalic acid-butanols, sec.-amyl alcohol, the 1-hexanol, 4-hydroxy-4-methyl-2-amylalcohol, 4-methyl-2-amylalcohol, hexalin, the DL-3-hexanol, the 1-enanthol, 2-Ethylhexyl Alcohol, (S)-(+)-sec-n-octyl alcohol, the 1-octanol, the DL-octanol, the 2-hydroxy-benzyl alcohol, the 2-nitrobenzyl alcohol, 3, the 5-dihydroxy-benzyl alcohol, 3,5-dinitrobenzene benzylalcohol, 3-fluoro benzylalcohol, the 3-hydroxy-benzyl alcohol, 4-fluoro benzylalcohol, the 4-hydroxy-benzyl alcohol, benzylalcohol, between (trifluoromethyl) benzylalcohol, between aminobenzyl alcohol, m-nitrobenzyl alcohol, adjacent aminobenzyl alcohol, adjacent hydroxy-benzyl alcohol, to hydroxy-benzyl alcohol, to nitrobenzyl alcohol, 2-(to fluorophenyl) ethanol, 2-amino-benzene ethanol, 2-methoxyl group benzylalcohol, 2-methyl-3-nitro benzylalcohol, the 2-xylyl alcohol, 2-oil of mirbane ethanol, the 2-phenylethyl alcohol, 3, the 4-dimethyl benzyl alcohol, 3-methyl-2-nitrobenzyl alcohol, 3-methyl-4-nitrobenzyl alcohol, the 3-xylyl alcohol, 4-fluorobenzene ethanol, 4-hydroxyl-3-methoxyl group benzylalcohol, 4-methoxyl group benzylalcohol, 4-methyl-3-nitro benzylalcohol, 5-methyl-2-nitrobenzyl alcohol, DL-α-hydroxyethylbenzene, adjacent (trifluoromethyl) benzylalcohol, to (trifluoromethyl) benzylalcohol, equal amido phenenyl alcohol, tyrosol, alcohols to xylyl alcohol and sec-phenethyl alcohol etc.; Phenols such as 4-methylphenol, 4-ethylphenol and 4-propionitrile phenol; Esters such as glyceryl ester, dehydration minashi sugar alcohol ester, methoxyacetic acid, ethoxyacetic acid, 3-ethoxy-propionic acid and alanine ethyl ester; Polyoxyethylene glycol, polypropylene glycol, polytetramethylene glycol, polyethylene glycol alkyl ether, the polyoxyethylene glycol alkenyl ether, the alkyl polyoxyethylene glycol, the alkyl polyethylene glycol alkyl ether, alkyl polyoxyethylene glycol alkenyl ether, the alkenyl polyoxyethylene glycol, the alkenyl polyethylene glycol alkyl ether, alkenyl polyoxyethylene glycol alkenyl ether, the polypropylene glycol alkyl oxide, the polypropylene glycol alkenyl ether, alkyl polypropylene glycol, the alkyl polypropylene glycol alkyl oxide, the alkyl polypropylene glycol alkenyl ether, the alkene polypropylene glycol, ethers such as alkenyl polypropylene glycol alkyl oxide and alkenyl polypropylene glycol alkenyl ether; Alginic acid, tartaric acid, carboxymethyl cellulose, coagulate polyoses such as polysaccharide (カ-De ラ Application) and pullulan; Amino acid saltss such as glycine ammonium salt and glycine sodium salt; Poly carboxylic acid and salt thereof such as poly aspartic acid, polyglutamic acid, polylysine, polymalic acid, polymethyl acrylic acid, ammonium polymethacrylate salt, sodium polymethacrylate salt, polyamic acid, polymaleic acid, poly-methylene-succinic acid, poly-fumaric acid, poly-(to the vinylbenzene carboxylic acid), polyacrylic acid, polyacrylamide, amino polyacrylamide, ammonium polyacrylate salt, polyacrylic acid sodium salt, polyamic acid ammonium salt, polyamic acid sodium salt and metaldehyde acid; Ethylene-based polymers such as polyvinyl alcohol, polypropylene pyrrolidone and polyacrolein; Sulfonic acid and salt thereof such as N-methyltaurine ammonium salt, N-methyltaurine sodium salt, sulfuric acid methyl sodium salt, sulfuric acid ethyl ammonium salt, sulfuric acid butyl ammonium salt, vinyl sulfonic acid sodium salt, 1-allyl sulphonic acid sodium salt, 2-allyl sulphonic acid sodium salt, methoxymethyl sulfonate sodium, ethoxyl methyl sulfonic acid ammonium salt, 3-ethoxycarbonyl propyl sulfonate sodium and sulfo-succinic acid sodium salt; Aniline, N, aromatic amines such as accelerine and benzyl amine; Propionic acid amide, acrylamide, methyl urea, niacinamide, succinamide, phenylacetic acid acid amides, pyridine-4-カ Le ボ キ サ ミ De, N ', acid amides such as N-dibenzyl-L-tartrate acid amides and sulfanilamide (SN); 1 ', 1-azo two (hexanaphthene-1-nitrile), 1 ', 1-azo two (1-acetoxyl group-1-diphenylphosphino ethane), 2 ', 2-azo two (2,4-dimethyl-valeronitrile), 2,2 '-two (the 4-methoxyl groups-2 of azo, 4-dimethyl-valeronitrile), 2,2 '-two (isopropylformic acid) dimethyl esters of azo, 2,2 '-azo two (isopropyl cyanide), 2-[2-(3,5-two bromo pyridyl) azo]-the 5-dimethylaminobenzoic acid, 4,4 '-azo two (4-cyanopentanoic acid), 4,4 '-azoxydianisole, the azoxy methylmethane, azo-group benzene, azoxy benzene, the azo-dicarboxylic acid amides, the diisopropyl azo-2-carboxylic acid, azo-2-carboxylic acid two (tert-butyl ester), azophenlyene, Victoria Green WPB, tropeolin-D, azo-compounds such as Congo red and Viola crystallina; And molybdenum compounds such as molybdenum (VI) acid disodium dihydrate and the sour six ammonium tetrahydrates of seven molybdenums (VI) etc.These compounds can use separately, also can appropriate combination use.
Under the situation that employed matrix is a semiconductor integrated circuit with silicon substrate etc., wish the pollution that do not produce, thereby wish it is acid or its ammonium salt by basic metal, alkaline-earth metal, halogenide etc.But, be under the situation of glass substrate etc. at matrix, should restriction.
Wherein, at high CMP speed and low corrosion speed and cubic plane; with 2-methyl-3-nitro benzylalcohol; polypropylene glycol; poly aspartic acid; polymalic acid; polyacrylic acid; polymethyl acrylic acid; ammonium polyacrylate; ammonium polymethacrylate; polyamic acid; the polyamic acid ammonium; polyacrylamide; N-methyltaurine sodium; benzylamine; niacinamide; sulfanilic amide; Congo red; the sour six ammonium tetrahydrates of seven molybdenums (VI) are good; especially, polyacrylic acid; polymethyl acrylic acid; polyamic acid; ammonium polyacrylate; ammonium polymethacrylate; polyamic acid ammonium and polyacrylamide the best.
As the metallic membrane that the present invention is suitable for, be to comprise at least a stacked film that is selected from copper, copper alloy, copper oxide and the copper alloy oxide compound (below, these merging are called copper alloy).
In addition, the invention provides CMP speed is that 100nm/min is above, corrosion speed is the following metal polishing slurry of 10nm/min.Lapping liquid with such characteristic; according to the present invention is first realization; the oxygenant, oxidized metal dissolving agent and the water that contain metal cooperate with the 2nd protective membrane formation agent different with the 1st protective membrane formation agent by making up the 1st protective membrane formation agent again, just can finish.
Below, illustrate with the 1st protective membrane that can use and form the combination of agent and the 2nd protective membrane formation agent as the 1st protective membrane formation agent/the 2nd protective membrane formation agent.These combinations only are simple illustrations, and the present invention is not subjected to the restriction of these combinations.As required, also can use other suitable combinations.
CMP speed is more than the 100nm/min as forming, corrosion speed is the combination below the 10nm/min, for example, can enumerate ball psytomin/polymalic acid, ball psytomin/poly aspartic acid, ball psytomin/polyacrylamide, L-tryptophane/polyacrylamide, L-tryptophane/ammonium polyacrylate, L-tryptophane/polymalic acid, benzotriazole/polyacrylamide, benzotriazole/ammonium polyacrylate, aphthotriazoles/polymalic acid, aphthotriazoles/2-methyl-3-nitro benzylalcohol, triazine two mercaptan/poly aspartic acid, triazine two mercaptan/polyacrylamide etc.
In addition, CMP speed is more than the 100nm/min as forming, corrosion speed is the combination below the 1nm/min, for example, can enumerate ball psytomin/polyacrylamide, L-tryptophane/polyacrylamide, L-tryptophane/ammonium polyacrylate, benzotriazole/polyacrylamide, benzotriazole/ammonium polyacrylate, aphthotriazoles/polymalic acid, triazine two mercaptan/poly aspartic acid, triazine two mercaptan/polyacrylamide etc.
More than CMP speed 250mm/min, the combination that corrosion speed 10nm/min is following can be enumerated ball psytomin/polymalic acid etc.
The use level of each composition then, is described.
The use level of oxidizer composition; form the total amount of agent, the formation agent of the 2nd protective membrane and water with respect to oxygenant, oxidized metal dissolving agent, the 1st protective membrane of 100g; better be 0.003mol～0.7mol, be more preferably 0.03mol～0.5mol, good especially is 0.2mol～0.3mol.During less than 0.003mol, the oxidation of metal is inadequate, thereby CMP speed is low in this use level, if surpass 0.7mol, just has abrasive surface to produce shaggy tendency.
The use level of oxidized metal dissolving agent composition in the present invention; form the total amount of agent, the formation agent of the 2nd protective membrane and water with respect to oxygenant, oxidized metal dissolving agent, the 1st protective membrane of 100g; better be 0.～0.005mol; be more preferably 0.00005mol～0.0025mol, good especially is 0.0005mol～0.0015mol.If this use level surpasses 0.005mol.Exist and be difficult to suppress the corrosive tendency.
The 1st protective membrane forms the use level of agent; form the total amount of agent, the formation agent of the 2nd protective membrane and water with respect to oxygenant, oxidized metal dissolving agent, the 1st protective membrane of 100g; better be 0.0001mol～0.05mol; be more preferably 0.0003mol～0.005mol, good especially is 0.0005mol～0.0035mol., exist to be difficult to suppress the corrosive tendency during in this use level less than 0.0001mol, if surpass 0.05mol, the tendency that just has CMP speed to reduce.
The 2nd protective membrane forms the use level of agent; form the total amount of agent, the formation agent of the 2nd protective membrane and water with respect to oxygenant, oxidized metal dissolving agent, the 1st protective membrane of 100g; better be 0.001～0.3 weight %; be more preferably 0.003 weight %～0.1 weight %, good especially is 0.01 weight %～0.08 weight %., exist in the control corrosion and can not embody the effect that forms agent and usefulness with the 1st protective membrane during in this use level less than 0.001 weight %, if surpass 0.3 weight %, the tendency that just exists CMP speed to reduce.
Though the mechanism of action of the performance of the effect in lapping liquid of the present invention and the Ginding process it be unclear that; but can be speculated as,, both suppress corrosion by also forming agent with the 1st and the 2nd protective membrane; for the friction that produces by grinding pad, under not having an effect, carry out CMP again as the metal surface protection film.
In general, in CMP, particle diameter or size distribution or the shape that the degree of hindering exists with ... solid abrasive particles takes place to grind, the thickness that causes by grinding off of insulating film reduce (below, be called wearing and tearing) or the deterioration of planarization effect, also exist with ... the physical properties of the particle diameter or the grinding pad of solid abrasive particles, handling metallic membrane with BTA, when especially copper film is surperficial, think that the hollow song of metallic membrane also exists with ... the hardness of grinding pad or the chemical property of lapping liquid.That is, hard solid abrasive particles is necessary when carrying out CMP, but the thoroughness (grind and hinder equivalent damage) in order to improve planarization effect among the CMP or CMP face is undesirable.Knew already that in fact the planarization effect depended on than the solid abrasive particles characteristic of softish grinding pad more.
Like this, think that the present invention can carry out under the solid abrasive particles on this aspect of CMP not having, at the CMP of copper alloy, to use in the formation of imbedding figure of CMP of copper alloy then be that the utmost point is wished.
The 1st protective membrane forms agent and has the effect that forms firm protective in the metallic surface.For example, if when the tin-copper alloy film surface is exposed in the solution that contains BTA, because the reaction of copper (Cu) or its oxide compound BTA, the structure that forms with Cu (I) BTA or Cu (II) BTA is the polymkeric substance shape coordination compound protective membrane of main framing.This protective membrane is quite firm, when use contains the metal polishing slurry of 0.5 weight %BTA, even contain solid abrasive particles in this lapping liquid, generally also grinds hardly.
On the other hand, do not using the 1st protective membrane to form agent, when only using the 2nd protective membrane to form agent modulation metal polishing slurry separately, especially be difficult to suppress corrosion speed, the protection effect is insufficient.
Like this, the 1st protective membrane forms agent and the 2nd protective membrane forms agent, and its effect is different, and the kind that forms agent according to protective membrane forms different types of protective membrane.The present invention is based on following new knowledge,, forms agent by being used in combination above-mentioned the 1st and the 2nd protective membrane that is, and the inhibition of corrosion speed and CMP speed are kept existed side by side, nor the strong friction that need produce by solid abrasive particles.
The best mode that carries out an invention
Below, according to embodiment the present invention is described.But the present invention is not subjected to the restriction of these embodiment.
Embodiment 1～12, comparative example 1～5
The lapping liquid modulator approach
In 0.15 parts by weight DL-oxysuccinic acid (reagent superfine), add 70 parts by weight water; and dissolving; after dissolving 0.2 parts by weight the 1st protective membrane forms the solution of agent formation in wherein being added in 0.8 parts by weight methyl alcohol; add 0.05 parts by weight the 2nd protective membrane again and form agent; add 33.2 parts by weight aquae hydrogenii dioxidi (reagent superfine at last; 30% aqueous solution), obtain metal polishing slurry.Form agent at the protective membrane that in each embodiment and comparative example, uses shown in the table 1.
Then, use the lapping liquid that obtains, grind grinding charge.Grinding conditions etc. are as follows.
Grinding condition
Ground substrate: the silicon substrate that forms the copper film of thick 1 μ m
Grinding pad: IC1000 (ロ デ-Le corporate system)
Grinding pressure: 210g/cm
2
The speed of relative movement on matrix and grinding chassis: 36m/min
The grinding object assessment item
CMP speed:, obtain CMP speed divided by the treatment time from convert film thickness difference before and after the CMP obtain copper film of resistance value.Treatment time is 1 minute.
Corrosion speed: prepare in addition to be ground the identical substrate of substrate with above-mentioned, at room temperature (25 ℃), stir (stirring velocity 100r/min) on one side, in lapping liquid, flood on one side, converse the copper layer film thickness difference that floods front and back from resistance value, obtain corrosion speed divided by dipping time.Dipping time is 10 minutes.
In addition, in order to estimate actual CMP characteristic, form the ditch of dark 0.5 μ m in insulation layer, form copper film according to known sputtering method, the silicon substrate of imbedding according to known thermal treatment uses as matrix again, carries out CMP.Confirm to have or not the generation abrasion and grind wound by range estimation, observation by light microscope and the electron microscope observation of the matrix behind the CMP.Its result does not see and abrasion takes place and grind wound.The CMP speed in embodiment 1～12 and comparative example 1～5 and the evaluation result of corrosion speed are shown in Table 1.
Table 1
| The 1st protective membrane forms agent | The 2nd protective membrane forms agent | CMP speed | Corrosion speed | |
| Embodiment 1 | The ball psytomin | Polymalic acid | 281 | 3.5 |
| Embodiment 2 | The ball psytomin | Poly aspartic acid | 234 | 1.9 |
| Embodiment 3 | The ball psytomin | Polyacrylamide | 187 | 0.3 |
| Embodiment 4 | The L-tryptophane | Polyacrylamide | 219 | 0.9 |
| Embodiment 5 | The L-tryptophane | Ammonium polyacrylate | 210 | 0.7 |
| Embodiment 6 | The L-tryptophane | Polymalic acid | 252 | 2.2 |
| Embodiment 7 | Benzotriazole | Ammonium polyacrylate | 185 | 0.2 |
| Embodiment 8 | Benzotriazole | Acrylamide | 196 | 0.4 |
| Embodiment 9 | Aphthotriazoles | Polymalic acid | 203 | 0.5 |
| Embodiment 10 | Aphthotriazoles | 2-methyl-3-nitre benzyl alcohol | 212 | 1.1 |
| Embodiment 11 | Triazine two mercaptan | Poly aspartic acid | 186 | 0.4 |
| Embodiment 12 | Triazine two mercaptan | Polyacrylamide | 224 | 1.0 |
| Comparative example 1 | The ball psytomin | (nothing) | 255 | 15.3 |
| Comparative example 2 | The L-tryptophane | (nothing) | 287 | 10.3 |
| Comparative example 3 | Benzotriazole | (nothing) | 93 | 2.4 |
| Comparative example 4 | Aphthotriazoles | (nothing) | 72 | 2.1 |
| Comparative example 5 | Triazine two mercaptan | (nothing) | 98 | 4.8 |
Embodiment 13
In 0.15 parts by weight DL-oxysuccinic acid (reagent superfine), add 70 parts by weight water, and dissolving, behind the solution that in wherein being added in 0.8 parts by weight methyl alcohol, dissolves 0.1 parts by weight BTA and form, add as 40% aqueous solution with 0.025 parts by weight ammonium polyacrylate again, add 33.2 parts by weight aquae hydrogenii dioxidi (reagent superfine at last, 30% aqueous solution), obtain metal polishing slurry.In the present embodiment, what use as oxidized metal dissolving agent is water-soluble high organic acid DL-oxysuccinic acid, and what form that agent uses as the 2nd protective membrane is water miscible ammonium polyacrylate salt.
Use this metal polishing slurry, when carrying out the CMP experiment under the condition identical with embodiment 1, CMP speed is that 287nm/min, corrosion speed are that 3.6nm/min is good.But, about forming the matrix of ditch figure, remove the necessary CMP of the thickness time of regulation than CMP and carry out 50% CMP grinding more, the result of electron microscope observation, the hollow song of the ditch portion of wide 10 μ m (becoming the part of imbedding distribution) is about 200nm.For hollow song is suppressed at below the 100nm, need be with superfluous CMP time limitation 20%.Abrasion does not take place and grind wound.
Embodiment 14
In 0.15 parts by weight DL-oxysuccinic acid (reagent superfine), add 70 parts by weight water, and dissolving, behind the solution that in wherein being added in 0.8 parts by weight methyl alcohol, dissolves 0.2 parts by weight BTA and form, add as 40% aqueous solution with 0.125 parts by weight ammonium polyacrylate salt again, add 33.2 parts by weight aquae hydrogenii dioxidi (reagent superfine at last, 30% aqueous solution), obtain metal polishing slurry.In the present embodiment, what use as oxidized metal dissolving agent is water-soluble high organic acid DL-oxysuccinic acid, and what form that agent uses as the 2nd protective membrane is water miscible vinylformic acid ammonium salt.
Use this metal polishing slurry, under the condition identical, carry out the CMP experiment with embodiment 1.Its result, it is high to 185nm/imn, the low result to 0.2nm/min of corrosion speed to obtain CMP speed.In addition, about in fact forming the matrix of ditch figure, also implement CMP in the same manner with above-mentioned CMP condition, when looking like above-mentioned observation, even if make superfluous CMP carry out time of suitable 50%, hollow song also is below the 50nm, abrasion does not take place yet and grinds and hinders.
Embodiment 15
Except using DL-tartrate to replace the DL-oxysuccinic acid and embodiment 14 modulates metal polishing slurry in the same manner and embodiment 1 carries out the CMP experiment in the same manner.Its result, grinding rate is high to 194nm/min, and corrosion speed is 0.8nm/min.In addition, the matrix that forms the ditch figure identical with embodiment 13 carried out CMP after, when observing substrate, the hollow song when superfluous CMP being ground carry out suitable 50% time is about 70nm, and abrasion and grinding wound do not take place.
Embodiment 16
Except using citric acid to replace the DL-oxysuccinic acid and embodiment 13 modulates metal polishing slurry in the same manner and embodiment 1 carries out the CMP experiment in the same manner.Its result, grinding rate is high to 213nm/min, but corrosion speed is 4.6nm/min, poor slightly.In addition, will form the observations after the time, superfluous CMP ground of the matrix suitable 30% of the ditch figure identical with embodiment 13, hollow song is below about 150nm, and abrasion and grinding wound do not take place.
Comparative example 6
Except not adding ammonium polyacrylate and embodiment 13 modulate metal polishing slurry and embodiment 1 in the same manner and carry out the CMP experiment in the same manner.Its result, CMP speed is low to being less than 140nm/min, and corrosion speed is inferior to 10.3nm/min.After the superfluous CMP that the matrix that forms the ditch figure identical with embodiment 13 is carried out suitable 30% time grinds, the result of observation matrix surface, hollow song increases to 300nm.Do not observe abrasion and grind wound.
Comparative example 7
Do not use ammonium polyacrylate, and make the addition of benzotriazole be increased to 0.2 parts by weight from 0.1 parts by weight, in addition and embodiment 13 modulate metal polishing slurry in the same manner, use this metal polishing slurry to carry out the CMP experiment identical with embodiment 1.
Its result, corrosion speed are 2.4nm/min, are good, but CMP speed is inferior to 93nm/min.In addition, to forming the matrix of the ditch figure identical with embodiment 13, after the superfluous CMP that implements suitable 30% time grinds, the result of observation matrix surface, hollow song is about 150nm, is not the value that can fully satisfy.Corrosion speed is low, but CMP speed is also low, needs long-time in CMP.Abrasion and scratch do not take place.
Find according to these embodiment and comparative example; only the 1st protective membrane is formed the concentration that agent is added into regulation; by forming agent with the 2nd protective membrane and using; even be lower than the lower concentration that the 1st protective membrane forms agent; also can reach the effect that is suppressed at the following corrosion speed of 10nm/min, and keep high CMP speed.Hence one can see that, suppress hollow bent, abrasion or grind the generation of hindering, and to form the high figure of imbedding of reliability with high CMP speed is possible.
Application possibility on the industry
As mentioned above,, can make corrosion speed fully low according to the present invention, and can keep high CMP speed and form reliability high imbed figure.
Claims (22)
1. metal polishing slurry, it contains oxygenant, oxidized metal dissolving agent, the 1st protective membrane and forms agent, forms agent different formation agent of the 2nd protective membrane and water with the 1st protective membrane.
2. the described metal polishing slurry of claim 1, wherein, it is to be selected from least a in ammonia, amine, amino acid, imines, azoles, mercaptan and the carbohydrate that above-mentioned the 1st protective membrane forms agent.
3. the described metal polishing slurry of claim 2, wherein, it is to be selected from least a in benzotriazole and the derivative thereof that above-mentioned the 1st protective membrane forms agent.
4. the described metal polishing slurry of claim 1, wherein, above-mentioned the 1st protective membrane forms agent to be by physical adsorption and/or to form chemical bond and form the compound of protective membrane in metallic film surface.
5. the described metal polishing slurry of claim 1, wherein, it is that corrosion speed is suppressed at compound below the 10nm/min that above-mentioned the 1st protective membrane forms agent.
6. the described metal polishing slurry of claim 1; wherein; above-mentioned the 2nd protective membrane forms agent, be in compound, ester, ether, polyose, amino acid salts, poly carboxylic acid, polycarboxylate, vinyl based polymer, acid amides, azo-compound and the molybdenum compound with alcohol or phenol hydroxyl at least any.
7. the described metal polishing slurry of claim 6, wherein, it is to be selected from least a in polyacrylic acid, polymethyl acrylic acid, polyamic acid, ammonium polyacrylate, ammonium polymethacrylate, polyamic acid ammonium and the polyacrylamide that above-mentioned the 2nd protective membrane forms agent.
8. the described metal polishing slurry of claim 1.Wherein, above-mentioned the 2nd protective membrane forms the compound that agent is auxiliary the 1st protective membrane formation agent formation protective membrane.
9. the described metal polishing slurry of claim 1, wherein, it is the compound that the addition that makes the 1st protective membrane form agent reduces that above-mentioned the 2nd protective membrane forms agent.
10. the described metal polishing slurry of claim 1, wherein, above-mentioned oxygenant is to be selected from least a in hydrogen peroxide, nitric acid, periodic acid potassium, hypochlorous acid and the ozone water.
11. the described metal polishing slurry of claim 1, wherein, above-mentioned oxidized metal dissolving agent is to be selected from least a in organic acid, organic acid ammonium salt and the sulfuric acid.
12. the described metal polishing slurry of claim 11, wherein, above-mentioned oxidized metal dissolving agent is to be selected from least a in oxysuccinic acid, tartrate, citric acid, oxysuccinic acid ammonium, ammonium tartrate and the ammonium citrate.
13. a metal polishing slurry, the cmp speed of this lapping liquid are that 100nm/min is above, corrosion speed is below the 10nm/min.
14. the described metal polishing slurry of claim 13, wherein, above-mentioned corrosion speed is below the 1nm/min.
15. the described metal polishing slurry of claim 13, wherein, above-mentioned cmp speed is more than the 250nm/min.
16. the described metal polishing slurry of each in the claim 13～15, it contains oxygenant, oxidized metal dissolving agent, the 1st protective membrane formation agent, forms agent different formation agent of the 2nd protective membrane and water with the 1st protective membrane.
17. claim 1 or 13 described metal polishing slurries, it is used for grinding any the metal at least that comprises copper, copper alloy, copper oxide and copper alloy oxide compound.
18. claim 1 or 13 described metal polishing slurries, it does not contain abrasive particle in fact.
19. a Ginding process, this Ginding process are the metallic membranes that removes the grinding charge surface in claim 1 or 13 described metal polishing slurries by grinding.
20. the described Ginding process of claim 19, wherein, above-mentioned metallic membrane comprise in copper, copper alloy, copper oxide and the copper alloy oxide compound at least any.
21. the described Ginding process of claim 19, this Ginding process is, above-mentioned grinding charge is to have stack membrane from the teeth outwards, this stack membrane has any the metal level at least that comprises in copper, silver alloys, silver oxide and the copper alloy oxide compound, and this Ginding process is a method of removing at least a portion of above-mentioned metal level from above-mentioned stack membrane.
22. the described Ginding process of claim 19, wherein, above-mentioned metal polishing slurry does not contain abrasive particle in fact.
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|---|---|---|---|
| JP24561698 | 1998-08-31 | ||
| JP1998245616 | 1998-08-31 | ||
| JP1998351188 | 1998-12-10 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB998127760A Division CN1204602C (en) | 1998-08-31 | 1999-08-31 | Abrasive liquid for metal and method for polishing |
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| CN1952034A true CN1952034A (en) | 2007-04-25 |
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| CN2008101869292A Expired - Lifetime CN101440259B (en) | 1998-08-31 | 1999-08-31 | Metal polishing solution and polishing method |
| CN 200610137146 Pending CN1952034A (en) | 1998-08-31 | 1999-08-31 | Abrasive liquid for metal and abrasive method |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN101580700B (en) * | 2008-05-16 | 2015-08-19 | 盟智科技股份有限公司 | The constituent of cmp |
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| KR100462132B1 (en) * | 1998-08-31 | 2004-12-17 | 히다치 가세고교 가부시끼가이샤 | Abrasive liquid for metal and method for polishing |
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| CN101580700B (en) * | 2008-05-16 | 2015-08-19 | 盟智科技股份有限公司 | The constituent of cmp |
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| CN101440259A (en) | 2009-05-27 |
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