WO2010063165A1

WO2010063165A1 - Chmical-mechanical polishing liquid

Info

Publication number: WO2010063165A1
Application number: PCT/CN2009/001366
Authority: WO
Inventors: 宋伟红; 姚颖
Original assignee: Song Peter Weihong; Yao Daisy Ying
Priority date: 2008-12-05
Filing date: 2009-12-04
Publication date: 2010-06-10
Also published as: CN101747841A; CN102239225A

Abstract

The invention discloses a chemical-mechanical polishing liquid which can remove dielectric material. The polishing liquid contains dimeric dumbbell-like and/or polymeric chain-like colloid silica abrasive particles having regular shape. The surface of polished wafer is glabrous and flat.

Description

Chemical mechanical polishing liquid

The present invention relates to a chemical mechanical polishing liquid. technical background

Abrasive particles of the polishing fluid in chemical mechanical planarization (CMP) technology are one of the key components, and different abrasive particles have different effects. Among the factors affecting the polishing performance, the abrasive particles tend to have a decisive effect, and its properties include various indicators such as the particle size distribution, shape, aggregation state of the abrasive particles and the solid content in the polishing liquid. The surface roughness of the wafer, the surface contamination particles, and the removal rate of various materials will have different effects. Conventional abrasive silica sol particles are spherical particles that are monodisperse (monomer, see Figure 1). The removal rate of various materials, especially dielectric materials, is limited, and only the abrasive particle content is increased to speed up the removal. Powdered silica abrasives, due to agglomeration of particles, form large particles, irregular shapes, and easily cause various defects such as surface scratches. Summary of invention

The technical problem to be solved by the present invention is to overcome the defects of the prior art chemical mechanical polishing liquid containing the conventional spherical monodisperse silica sol particles or the powdered silica abrasive, which has a limited removal rate or easily causes micro scratches on the original surface of the wafer, and provides A chemical mechanical polishing fluid having a high removal rate and good surface finish and flatness after polishing.

The chemical mechanical polishing liquid of the present invention contains dimeric 3⁄4 bell-shaped and/or poly-chain silica sol abrasive particles (Fig. 1) and water.

I

Confirmation Wherein, the dimerized dumbbell-shaped or poly-chain-shaped silica sol abrasive particles preferably have a particle size of 10 to 150 nm, more preferably 20 to 100 nm, most preferably 30 to 100 nm; The content of the dimeric dumbbell-shaped and/or poly-chain silica sol abrasive particles is 1-20%, and the percentage is mass percentage.

The chemical mechanical polishing liquid of the present invention may further contain one or more of a surfactant, an oxidizing agent, a film forming agent and a chelating agent, as needed.

In a preferred embodiment of the invention, the chemical mechanical polishing liquid contains dimeric dumbbell-shaped and/or poly-chain silica sol abrasive particles, a surfactant, and water. The chemical mechanical polishing liquid is suitable for polishing materials having different dielectric constants, and is preferably suitable for insulating films of silicon oxide (PETEOS) and carbon-doped silicon oxide.

In another preferred embodiment of the present invention, the chemical mechanical polishing liquid contains dimeric bell-shaped and/or poly-chain silica sol abrasive particles, an oxidizing agent, a film former, a chelating agent, a surfactant, and water. . The chemical mechanical polishing fluid is preferably suitable for polishing copper or barrier materials.

Wherein, the surfactant is a surfactant conventionally used in the art, and its function is to adjust the polishing selection ratio between different materials, especially the selection ratio between different silicon-based materials, such as silicon dioxide and carbon ginseng. Miscellaneous silicon dioxide, silicon nitride, silicon carbide, silicon oxynitride, and the like. The surfactant is preferably one or more of a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant. The cationic surfactant is preferably a polyethyleneimine and/or a quaternary ammonium salt surfactant having a number average molecular weight of from 2,000 to 50,000 (e.g., hexadecanyltrimethylammonium chloride); The surfactant is preferably a polyacrylic polymer having a number average molecular weight of from 1,000 to 50,000, and may be a homopolymer or a copolymer; and the amphoteric surfactant is preferably a betaine surfactant. The nonionic surfactant Preferred are polyethylene glycol having a number average molecular weight of 200 to 20,000 and/or a polyoxyethylene ether having a hydrophilic hydrophobic balance (HLB value) of 5 to 15. The content of the surfactant is preferably 0.001 to 0.1%, more preferably 0.005 to 0.05%, and the percentage is percentage by mass.

Wherein, the oxidizing agent is an oxidizing agent conventionally used in the art, preferably one or more of a peroxide, a persulfide and an ammonium nitrate; more preferably hydrogen peroxide, urea hydrogen peroxide, or One or more of oxyacetic acid, benzoyl peroxide, potassium persulfate, ammonium persulfate and ammonium nitrate; the content of the oxidizing agent is 0.1 to 10% by mass.

Wherein, the film-forming agent is a film-forming agent conventionally used in the art, and its function is to form an insoluble protective film on the metal surface to achieve the purpose of corrosion inhibition and improvement of planarization efficiency. The film-forming agent is preferably an azole organic compound; more preferably benzotriazole and a derivative thereof, and one or more of tetrazole and a derivative thereof. The benzotriazole derivative is preferably a carboxy- and/or ester-substituted benzotriazole derivative; the tetrazole derivative is preferably a phenyl-substituted tetrazole derivative or a fluorenyl group. Substituted tetrazole derivatives, amino-substituted tetrazole derivatives, phenyl and mercapto-substituted tetrazole derivatives, phenyl and amino-substituted tetrazole derivatives, mercapto and amino-substituted tetrazole derivatives, and phenyl One or more of a tetrazole derivative in which a mercapto group and an amino group are co-substituted; the ester-substituted triazole derivative is a decyloxycarbonyl-substituted triazole derivative and/or an aryloxycarbonyl group substituted Triazole derivatives. The most preferred film forming agent is benzotriazole, benzimidazole, hydrazine, methylbenzotriazole, carbazole, N-methylbenzotriazole, 4-carboxybenzotriazole Ester, 5-carboxybenzotriazole methyl ester, 4-carboxybenzotriazole butyl ester, 5-carboxybenzotriazole butyl ester, 4-hydroxybenzotriazole, 5-hydroxybenzotriazole, One or more of 1-H tetrazole, 5-aminotetrazolium, 5-methyl-tetrazole and 1-phenyl-5-mercaptotetrazole. The content of the film-forming agent is preferably 0.001 to 1%, more preferably 0.05 to 0.5%, most preferably 0.1 to 0.4%, and the percentage is percentage by mass. The chelating agent is a chelating agent conventionally used in the art, and is selected from one or more of an organic phosphine, a nitrogen-containing heterocyclic ring, an organic amine, and a water-soluble carboxylic acid-based polymer. Wherein, the organophosphine is preferably a chelating agent of an organic phosphoric acid compound and/or an organophosphate compound, more preferably hydroxyethylidene diphosphonic acid (HEDP) or aminotrimethylene phosphonic acid (ATMP) ), ethylenediamine tetramethylene phosphonic acid (EDTMP), diethylene triamine penta methylene phosphonic acid (DTPMP), 2-phosphonic acid butane-1, 2, 4 tricarboxylic acid (PBTCA), One or more of 2-hydroxyphosphonoacetic acid (HPAA), polyaminopolyethermethylenephosphonic acid, and polyol phosphate (PAPEMP). Wherein, the nitrogen-containing heterocyclic ring is preferably one or more of a six-membered heterocyclic ring containing two nitrogen atoms, a six-membered heterocyclic ring of three nitrogen atoms, and a five-membered heterocyclic ring containing two nitrogen atoms. More preferably, it is one or more of a pyrimidine, a pyridine, a piperidine, a piperazine, a pyridazine, a morpholine, an amino-substituted triazole compound, and a carboxyl-substituted triazole compound. Wherein, the organic amine compound is preferably one or more of a primary amine, a secondary amine, a tertiary amine and a quaternary ammonium compound, more preferably a diamine, a polyenepolyamine and a cyclic amine. One or more, such as hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, cyclohexylamine, and the like. Wherein, the water-soluble carboxylic acid-based polymer comprises a homopolymer and a copolymer, and also includes a salt of a polycarboxylic acid compound, preferably a sodium salt or an ammonium salt, preferably polyacrylic acid, polyacrylate, polyacrylic acid. Homopolymers of sodium salt, ammonium polyacrylate, polymaleic acid, polyepoxysuccinic acid and polyaspartic acid, acrylic acid-acrylate copolymer, acrylic acid-maleic acid copolymer and acrylic acid-organic phosphoric acid-sulfonate One or more of the acid salt copolymers. The number average molecular weight of the water-soluble carboxylic acid-based polymer is preferably 200,5000. The content of the organic chelating agent is preferably 0.001 to 5% by mass, more preferably 0.1 to 2% by mass, most preferably 0.2 to 1.5% by mass.

In the present invention, the water is preferably deionized water, and the amount of water is 100% by mass. The chemical mechanical polishing liquid of the present invention may further contain other conventional additives in the art such as a viscosity modifier, a stabilizer, an antifungal agent, and a bactericide.

The pH of the chemical mechanical polishing liquid in the invention affects the polishing performance, and the polishing effect on the silicon oxide material under the acidic condition is better, and the polishing effect on the carbon doped silicon oxide is better under the alkaline condition, and the preferred chemical mechanical mechanism The pH of the polishing liquid is 2 to 4 or 9 to 12.

The polishing liquid of the present invention can be obtained by simply and uniformly mixing the above components, and then adjusting to a suitable pH value using a pH adjuster. _{The P} H regulator may be selected from conventional pH adjusting agents in the art, such as potassium hydroxide, aqueous ammonia, and nitric acid.

The reagents and starting materials used in the present invention are commercially available.

The positive progressive effect of the present invention is that the chemical mechanical polishing liquid containing the dimeric dumbbell-shaped or poly-chain-shaped silica sol particle abrasive of the present invention is superior to the conventional spherical monodisperse silica sol particle as the abrasive polishing liquid. The polishing effect of the dielectric material has a higher removal rate, and the abrasive particle shape is regular, and the surface roughness and flatness of the polished wafer are better, which can meet the requirements of the surface of the dielectric material under various process conditions, and solves the problem. The chemical mechanical polishing liquid polishing of conventional silica sol particles has a limited removal rate and micro scratching problems. DRAWINGS

Figure 1 is a plot of the aggregation state and shape of silica particles. Summary of the invention

The invention is further illustrated by the following examples, which are not intended to limit the invention. Examples 1 to 11

Table 1 shows the formulations of the chemical mechanical polishing liquids of the present invention in Examples 1 to 11, according to the components listed in Table 1 and their contents, the percentages are all simply mixed uniformly by mass percentage, and the polishing liquid content is supplemented with deionized water to The percentage of mass is 100%, and the pH of the polishing solution is adjusted to the listed value by a pH adjuster to prepare each chemical mechanical polishing liquid.

Surfactant 0.04

Polyethylene glycol (number average molecular weight 20000)

Poly

90 8 oxidant potassium persulfate 10 10 chain

Film former 1 -H tetrazolium 0.1 Chelating agent Cyclohexylamine 2 Surfactant Hexadecyltrimethylammonium chloride 0.03 Dimerization oxidant Persulfate hinge 8

150 12 11 Dumbbell Forming Agent Benzimidazole 0.4

Chelating agent Acrylic-acrylate copolymer (number average molecular weight 200) 5 Surfactant Polyoxyethylene ether (HLB value 15) 0.06 Dimerization oxidant Nitric acid hinge 6

100 16 12 Dumbbell Shape Film Forming Agent 吲哚 0.2

Chelating agent Piperazine 3 Surfactant Polyethylenimine (number average molecular weight 3000) 0.08 Poly oxidizing agent Hydrogen peroxide 3

70 19 11 Chain Forming agent 1 -Phenyl-5-mercaptotetrazole 0.6

Chelating agent 2-Hydroxyphosphonoacetate 0.8 Surfactant Hexylmercaptotrimethylammonium chloride 0.07 Dimerization Oxidant Hydrogen peroxide 0.5

50 3 3 Dumbbell Forming Agent Carboxyl-substituted benzotriazole Methyl Ester 0.005

Chelating agent Polymaleic acid homopolymer (number average molecular weight 200) 0.05 Surfactant Polyoxyethylene ether (HLB value 10) 0.08 Poly oxidizing agent Benzoyl peroxide 2

80 5 4 chain form film former carboxy ester group substituted benzotriazole 0.5

Chelating agent hexamethylenediamine 2 surfactant polyethylene glycol (number average molecular weight 15000) 0.004 dimerization oxidant persulfate hinge 4

120 15 10 Dumbbell Forming agent 4-carboxybenzotriazole butyl ester 0.25

Chelating agent 3-Amino, 5-carboxy, 1 , 2, 4 triazole 4 Surfactant Polyethylenimine (number average molecular weight 5000) 0.008 Poly oxidizing agent Ammonium nitrate 6

40 9 11 Chain Forming Agent 5-Aminotetrazolium 0.026

Chelating agent 2-phosphonic acid butyl '垸 -1, 2, 4 tricarboxylic acid 0.005 Surfactant Polyethylenimine (number average molecular weight 7000) 0.015 Oxidizing agent Hydrogen peroxide 0.1 Dimerization

30 10 Film-forming agent 5-carboxybenzotriazole methyl ester 0.001 2 Dumbbell shape

Chelating agent ethylenediaminetetramethylenephosphonic acid 0.001 stabilizer urea 1% Effect embodiment

Effect of silica sol particles with different shapes and sizes on polishing effect under the same conditions

The polishing fluids in Table 2 are abrasive particles plus pH adjuster and deionized water without other components. Polishing conditions: Polishing machine is Logitech (UK) PM50, politex polishing pad, grinding pressure 2 psi, grinding table The rotation speed is 70 rpm, the rotation speed of the grinding head is 90 rpm, and the dropping speed is 100 ml/min.

Table 2

Silica removal rate A/Min

Subtle example pH uniformity

CDO Scratch Shape Particle Size Content PETEOS

2.0 311 387 10% Small amount Traditional 3.0 316 444 10% Small amount Monodisperse ball

Abrasive 50nm 10%

Shape 10.0 343 94 11% Small amount Reference ' .1

12.0 584 230 12% have

2.0 358 412.2 10% 少里 Traditional 3.0 313 445 10% Small amount of monodisperse ball

Abrasive 80nm 10%

Shape 10.0 356 120 1 1% Small amount Reference 2

12.0 521 336 12% have

2.0 562 940 <5% none

3.0 499 955 <5% no dimer dumbbell

14 50nm 10%

Shape 10.0 682 374 <5% None

12.0 1475 785 <5% None

2.0 384 1 168 <5% None

3.0 169 1 199 <5% no poly chain

15 80nm 10%

Shape 10.0 550 426 <5% None

12.0 1460 882 <5% None

2.0 622 759 <5% none

3.0 534 651 <5% no dimer dumbbell

16 80nm 10%

Shape ) 0.0 728 196 <5% None

12.0 1600 824 <5% no CDO: Carbon-doped silica, a low dielectric material.

As can be seen from Table 2, the 3⁄4 bell-shaped or chain-shaped sol particles used in the present invention have a higher dielectric material removal rate.

In Examples 15 and 16, compared with Reference 2, the use of dimeric dumbbell-shaped particles and poly-chain particles under acidic conditions, the removal rate of PETEOS was significantly improved, especially the dimeric dumbbell-shaped particles increased nearly three times, carbon ginseng The removal rate of miscellaneous low dielectric materials has increased by nearly 30%; while under alkaline conditions, especially at high pH, the removal rate of CDO has increased greatly, up to four times, and PETEOS has twice as much improvement. At the same time, the removal rate distribution of the wafer center and the edge region is investigated: the difference between the maximum removal rate and the minimum removal rate in different regions is a percentage of the average removal rate, that is, the uniformity of polishing, and the polishing liquid of the present invention is found by comparison. The dimeric dumbbell-shaped and/or multi-chain sol particles used have good polishing uniformity on the surface of the polished dielectric material, and are not slightly scratched, and can satisfy the dielectric surface of various process conditions. Claim.

Claims

Rights request

A chemical mechanical polishing liquid comprising dimeric dumbbell-shaped and/or poly-chain silica solute abrasive particles and water.

The chemical mechanical polishing liquid according to claim 1, wherein the dimeric mute bell-shaped or poly-chain-shaped silica sol abrasive particles have a particle size of 10 to 150 nm.

The chemical mechanical polishing liquid according to claim 2, wherein the dimeric mute-shaped or poly-chain-shaped silica sol abrasive particles have a particle size of 20 to 100 nm.

4. The chemical mechanical polishing liquid according to claim 3, wherein the dimeric mute-shaped or poly-chain-shaped silica sol abrasive particles have a particle size of 30 to 100 nm.

The chemical mechanical polishing liquid according to claim 1, wherein the dimeric dumbbell-shaped and/or poly-chain silica sol abrasive particles are in an amount of 1 to 20%, and the percentage is mass percentage. .

The chemical mechanical polishing liquid according to claim 1, wherein the chemical mechanical polishing liquid further contains one or more of a surfactant, an oxidizing agent, a film forming agent, and a chelating agent.

The chemical mechanical polishing liquid according to claim 6, wherein the chemical mechanical polishing liquid further contains a surfactant, or further contains a surfactant, an oxidizing agent, a film forming agent, and a chelating agent.

The chemical mechanical polishing liquid according to claim 6 or 7, wherein the surfactant is a cationic surfactant, an anionic surfactant, an amphoteric surfactant, and a nonionic surfactant. One or more; the oxidizing agent is one or more of a peroxide, a persulfide and an ammonium nitrate; the film forming agent is an azole organic substance; and the chelating agent is an organic phosphine, including One or more of a nitrogen heterocyclic ring, an organic amine, and a water-soluble carboxylic acid-based polymer.

9. The chemical mechanical polishing liquid according to claim 8, wherein: the azole organic substance is benzotriazole and a derivative thereof, and one or more of tetrazole and a derivative thereof; The organophosphine is a chelating agent of an organic phosphoric acid compound and/or an organophosphate compound; the nitrogen-containing heterocyclic ring is a six-membered heterocyclic ring containing two nitrogen atoms, and a six-membered ring containing three nitrogen atoms. One or more of a heterocyclic ring and a five-membered heterocyclic ring containing two nitrogen atoms; the organic amines being one or more of a primary amine, a secondary amine, a tertiary amine, and a quaternary ammonium compound; The water-soluble carboxylic acid-based polymer is one or more selected from the group consisting of a water-soluble carboxylic acid-based homopolymer, a water-soluble carboxylic acid-based copolymer, and a polycarboxylic acid-based compound.

The chemical mechanical polishing liquid according to claim 9, wherein: said benzotriazole derivative is a carboxy- and/or ester-substituted benzotriazole derivative; said tetrazole derivative a phenyl substituted tetrazole derivative, a mercapto substituted tetrazole derivative, an amino substituted tetrazole derivative, a phenyl and a decyl substituted tetrazole derivative, a phenyl and an amino substituted tetrazole derivative, a fluorenyl group And an amino-substituted tetrazole derivative, and one or more of a tetrazole derivative in which a phenyl group, a fluorenyl group and an amino group are co-substituted.

11. The chemical mechanical polishing liquid according to claim 8, wherein: said oxidizing agent is hydrogen peroxide, urea hydrogen peroxide, peracetic acid, benzoyl peroxide, potassium persulfate, ammonium persulfate, and One or more of ammonium nitrate; the cationic surfactant is polyethyleneimine and/or hexadecanyltrimethylammonium chloride having a number average molecular weight of from 2,000 to 50,000; said anionic surface active The agent is a polyacrylic polymer having a number average molecular weight of 1000 to 50000; the amphoteric surfactant is a betaine surfactant; and the nonionic surfactant is a polyethylene having a number average molecular weight of 200-20000. a polyoxyethylene ether having an alcohol and/or hydrophilic hydrophobic balance value of 5 to 15; the film forming agent is benzotriazole, 4-carboxybenzotriazole methyl ester, 5-carboxybenzotriazole Methyl ester, 4-carboxybenzotriazole butyl ester, 5-carboxybenzotriazole butyl ester, 4-hydroxybenzotriazole, 5-hydroxybenzotriazole, benzimidazole, hydrazine, methylbenzene And triazole, carbazole, N-methylbenzotriazole,

One or more of 1-H tetrazolium, 5-aminotetrazolium, 5-methyl-tetrazole and 1-phenyl-5-mercaptotetrazole; the chelating agent is hydroxy-ethylidene Diphosphonic acid, aminotrimethylenephosphonic acid, ethylenediaminetetramethylenephosphonic acid, diethylenetriaminepentamethylenephosphonic acid, 2-phosphonic acid butane-1, 2,4 tricarboxylic acid ,

2-Hydroxyphosphonoacetic acid, polyaminopolyethermethylenephosphonic acid, polyol phosphate, pyrimidine, pyridine, piperidine, piperazine, pyridazine, morpholine, amino substituted triazole compound, carboxy substituted Triazole compound, hexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, cyclohexylamine, polyacrylic acid, polyacrylate, sodium polyacrylate, ammonium polyacrylate, polymaleic acid Polymer, polyepoxysuccinic acid homopolymer, polyaspartic acid homopolymer, acrylic acid-acrylate copolymer, acrylic acid-maleic acid copolymer and acrylic acid-organic phosphoric acid-sulfonate copolymer Or a variety.

The chemical mechanical polishing liquid according to claim 8, wherein the water-soluble carboxylic acid polymer has a number average molecular weight of from 200 to 5,000.

The chemical mechanical polishing liquid according to claim 6 or 7, wherein the surfactant is contained in a mass ratio of 0.001 to 0.1%; and the oxidizing agent is contained in an amount of 0.1 to 10%; The film-forming agent is contained in an amount of 0.001 to 1%; the chelating agent is contained in an amount of 0.001 to 5%; and the percentage is a mass percentage.

The chemical mechanical polishing liquid according to claim 1, wherein the chemical mechanical polishing liquid has a pH of 2 to 4 or 9 to 12.