JP2005255983A - Cleaning composition, method for washing semiconductor substrate, and manufacturing method for semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a cleaning composition which has a high ability to remove impurities such as residual abrasive grains, residual polishing wastes, and metal ions without corroding metal wirings when contaminants on the surface of a semiconductor substrate having the metal wirings are removed after the substrate is subjected to chemical and mechanical polishing, to provide a washing method for the semiconductor substrate using the same, and a manufacturing method for a semiconductor device including the washing method. <P>SOLUTION: The cleaning composition to use after the chemical and mechanical polishing contains (A) an organic polymer particle having a crosslinking structure and (B) a surfactant. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cleaning composition, a cleaning method, and a method for manufacturing a semiconductor device. More specifically, a cleaning composition that can be suitably used in a cleaning process after chemical mechanical polishing of a semiconductor substrate, particularly a semiconductor substrate having metal wiring, a cleaning method using the cleaning composition, and a cleaning method The present invention relates to a method for manufacturing a semiconductor device including a step of cleaning a semiconductor substrate after chemical mechanical polishing.

  A chemical mechanical polishing technique is employed as a planarization technique in the manufacture of semiconductor devices. In this chemical mechanical polishing, the object to be polished is bonded to the polishing pad, and the object to be polished and the polishing pad are slid relative to each other while supplying the chemical mechanical polishing dispersion onto the polishing pad. This is a technology for mechanical and mechanical polishing. Here, the chemical mechanical polishing dispersion usually contains various chemicals such as an etching agent and a complexing agent in addition to the abrasive grains. Therefore, abrasive grains and polishing waste may remain on the polished surface after polishing. In addition, when there is a wiring portion made of a metal material on the surface to be polished, metal ions that are chemically extracted from the surface to be polished by the action of chemicals in the chemical mechanical polishing dispersion are reappeared on the surface to be polished. Contamination of the polished surface after polishing may inevitably occur due to adsorption.

  In recent years, with the remarkable high integration of semiconductor devices, even the contamination by a very small amount of impurities has greatly affected the performance of the device, and thus the product yield. For this reason, stricter contamination control is required more than ever.

One such contamination control is cleaning of the polished surface after polishing, and methods for removing contamination of the polished surface with various cleaning agents have been proposed.
For example, a cleaning method using a cleaning agent containing hydrofluoric acid or ammonia has been proposed for removing contamination of an insulating film after chemical mechanical polishing (see Non-Patent Documents 1 and 2). However, since a cleaning agent containing hydrofluoric acid corrodes a metal material, it cannot be applied to a semiconductor substrate having a metal wiring portion. In addition, a cleaning agent containing ammonia cannot be applied to a copper wiring board which is a mainstream in recent years because it corrodes copper in particular.

  On the other hand, a cleaning agent containing citric acid as a main component has been proposed as a cleaning agent that does not corrode metal materials (see Patent Document 1 and Non-Patent Document 3). However, these cleaning agents do not have sufficient decontamination capability, and do not meet the recent demands for strict contamination control.

In view of the above, there has been a demand for a cleaning agent that does not corrode metal materials, particularly copper, and has sufficient decontamination capability to meet the recent demands for strict contamination control.
Japanese Patent Laid-Open No. 10-72594 “Hydrogen Peroxide Solutions for Silicon Wafer Cleaning”, RCA Engineer, 28 (4), p9 (1983). “Clean Solutions Based in Hydrogen Peroxide for Use in Silicon Semiconductor Technology”, RCA Review, 31, p187 (1970). Semiconductor World, No. 3, p92 (1997)

  The present invention is intended to solve the problems associated with the prior art as described above, and when a semiconductor substrate having metal wiring is subjected to chemical mechanical polishing and then the contamination of the substrate surface is removed, the metal wiring is corroded. In addition, an object of the present invention is to provide a cleaning composition having a high ability to remove residual abrasive grains, residual polishing waste, and impurities such as metal ions. Another object of the present invention is to provide a cleaning method capable of efficiently removing contamination on a polished surface of a semiconductor substrate after chemical mechanical polishing. It is another object of the present invention to provide a method for manufacturing a high-quality semiconductor device that is not contaminated by impurities.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by using a cleaning composition containing organic polymer particles having a crosslinked structure and a surfactant. The present invention has been completed.

That is, the cleaning composition according to the present invention is used after chemical mechanical polishing, and contains organic polymer particles (A) having a crosslinked structure and a surfactant (B).
The organic polymer particles (A) having a crosslinked structure are a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, and —N ⁺ R ₃ (where R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). It is preferable to have at least one functional group selected from the group consisting of: The average dispersed particle size of the organic polymer particles (A) having a crosslinked structure is preferably 120 to 500 nm. Furthermore, the organic polymer particles (A) having a crosslinked structure include a carboxyl group-containing unsaturated monomer (a1), a polyfunctional monomer (a2), and the monomers (a1) and (a2). Particles made of a copolymer with an unsaturated monomer other than (a3) are preferred.

  The method for cleaning a semiconductor substrate according to the present invention is characterized in that the semiconductor substrate after chemical mechanical polishing is cleaned using the cleaning composition. The cleaning is preferably at least one cleaning selected from the group consisting of cleaning on a platen, brush scrub cleaning, and roll cleaning.

  A method of manufacturing a semiconductor substrate according to the present invention includes a step of chemically mechanically polishing a semiconductor substrate, and a step of cleaning the semiconductor substrate after chemical mechanical polishing by the cleaning method.

  According to the present invention, when removing contamination on the surface of a semiconductor substrate having a metal wiring after chemical mechanical polishing, the metal wiring is not corroded and impurities such as residual abrasive grains, residual polishing waste and metal ions are removed. A cleaning composition having a high ability can be obtained. Further, by using this cleaning composition, the surface to be polished of the semiconductor substrate after chemical mechanical polishing can be cleaned to efficiently remove contamination on the surface to be polished. Furthermore, a high-quality semiconductor device free from contamination by impurities or the like can be manufactured.

[Cleaning composition]
The cleaning composition according to the present invention contains (A) organic polymer particles having a crosslinked structure and (B) a surfactant.

(A) Organic polymer particles having a crosslinked structure The organic polymer particles (A) used in the present invention have a crosslinked structure (hereinafter referred to as “crosslinked organic polymer particles (A)”). By using the crosslinked organic polymer particles (A), it is possible to obtain a cleaning composition capable of maintaining or improving the ability to remove impure metal ions of a conventionally known cleaning agent and suppressing the occurrence of surface defects. .

The crosslinked organic polymer particle (A) contains a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, and —N ⁺ R ₃ (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). It preferably has at least one functional group selected from the group consisting of: By using the crosslinked organic polymer particles (A) having such a functional group, a high ability to remove impure metal ions is exhibited. Of the functional groups, a carboxyl group and a hydroxyl group are preferable, and a carboxyl group is more preferable.

  The average dispersed particle diameter of the crosslinked organic polymer particles (A) is preferably 100 to 1,000 nm, more preferably 120 to 500 nm, and further preferably 150 to 250 nm. When the average dispersed particle size is in the above range, a cleaning composition excellent in both stability and decontamination capability can be obtained.

  Examples of such crosslinked organic polymer particles (A) include a carboxyl group-containing unsaturated monomer (a1), a polyfunctional monomer (a2), and the monomers (a1) and (a2). And particles made of a copolymer with an unsaturated monomer (a3) other than.

(A1) Carboxyl group-containing unsaturated monomer The carboxyl group-containing unsaturated monomer (a1) is a monomer having a carboxyl group and a polymerizable unsaturated bond, such as an unsaturated monocarboxylic acid, Examples thereof include unsaturated polyvalent carboxylic acids and mono [(meth) acryloyloxyalkyl] esters of polyvalent carboxylic acids.

Examples of the unsaturated monocarboxylic acid include (meth) acrylic acid, crotonic acid, α-chloroacrylic acid, cinnamic acid, and the like.
Examples of the unsaturated polycarboxylic acid include maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, and mesaconic acid.

  Examples of the mono [(meth) acryloyloxyalkyl] ester of the polyvalent carboxylic acid include succinic acid mono [2- (meth) acryloyloxyethyl] and phthalic acid mono [2- (meth) acryloyloxyethyl]. And the like.

  These carboxyl group-containing unsaturated monomers can be used alone or in combination of two or more. Of the carboxyl group-containing unsaturated monomers (a1), unsaturated monocarboxylic acids are preferable, and (meth) acrylic acid is more preferable.

(A2) Polyfunctional monomer The polyfunctional monomer (a2) is a monomer having two or more polymerizable unsaturated bonds. As such a polyfunctional monomer (a2), a divinyl aromatic compound, polyvalent (meth) acrylate, etc. can be mentioned, for example.

Examples of the divinyl aromatic compound include vidinylbenzene.
Examples of the polyvalent (meth) acrylate include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1, 4-butylene glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, 2, Di (meth) acrylates such as 2′-bis (4-methacryloxydiethoxyphenyl) propane; trimethylolethane tri (meth) acrylate, tetramethylolmethane tri (meth) acrylate, trimethylo And tri (meth) acrylates such as propane propane tri (meth) acrylate and pentaerythritol triacrylate; and tetrafunctional or higher polyvalent acrylates such as tetramethylolmethane tetraacrylate.

  These polyfunctional monomers can be used individually by 1 type or in mixture of 2 or more types. Of the polyfunctional monomers (a2), divinyl aromatic compounds, di (meth) acrylates and tri (meth) acrylates are preferable, and divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane tri (meth) acrylate and penta Erythritol triacrylate is more preferred.

(A3) Unsaturated monomer other than the above monomers (a1) and (a2) The unsaturated monomer (a3) is composed of the above carboxyl group-containing unsaturated monomer (a1) and the above polyfunctional monomer. It is a monomer other than the monomer (a2) and has at least one polymerizable unsaturated bond. Examples of the unsaturated monomer (a3) include aromatic vinyl compounds, unsaturated carboxylic acid esters, unsaturated carboxylic acid aminoalkyl esters, unsaturated amides, and aliphatic conjugated dienes.

  Examples of the aromatic vinyl compound include styrene, α-methylstyrene, o-vinyltoluene, m-vinyltoluene, p-vinyltoluene, p-chlorostyrene, o-methoxystyrene, m-methoxystyrene, and p-methoxystyrene. O-vinyl benzyl methyl ether, m-vinyl benzyl methyl ether, p-vinyl benzyl methyl ether, o-vinyl benzyl glycidyl ether, m-vinyl benzyl glycidyl ether, p-vinyl benzyl glycidyl ether and the like.

  Examples of the unsaturated carboxylic acid ester include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl ( (Meth) acrylate, sec-butyl (meth) acrylate, t-butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxy Butyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, allyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) Chryrate, 2-methoxyethyl (meth) acrylate, 2-phenoxyethyl (meth) acrylate, methoxydiethylene glycol (meth) acrylate, methoxytriethylene glycol (meth) acrylate, methoxypropylene glycol (meth) acrylate, methoxydipropylene glycol (meta ) Acrylate, isobornyl (meth) acrylate, dicyclopentadienyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, glycerol mono (meth) acrylate, and the like.

  Examples of unsaturated carboxylic acid aminoalkyl esters include 2-aminoethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, 2-aminopropyl (meth) acrylate, 2-dimethylaminopropyl (meth) acrylate, Examples thereof include 3-aminopropyl (meth) acrylate and 3-dimethylaminopropyl (meth) acrylate.

Examples of the unsaturated amide include (meth) acrylamide, α-chloroacrylamide, N-2-hydroxyethyl (meth) acrylamide and the like.
Examples of the aliphatic conjugated diene include 1,3-butadiene, isoprene, chloroprene and the like.

  These unsaturated monomers can be used individually by 1 type or in mixture of 2 or more types. Of the unsaturated monomers (a3), aromatic vinyl compounds and unsaturated carboxylic acid esters are preferable, and styrene, α-methylstyrene, methyl (meth) acrylate, cyclohexyl (meth) acrylate, and phenyl (meth) acrylate. Is more preferable.

  The crosslinked organic polymer particles (A) include the carboxyl group-containing unsaturated monomer (a1), the polyfunctional monomer (a2), the monomer (a1), and the monomer (a2). In the case of particles composed of a copolymer with an unsaturated monomer (a3) other than), the copolymerization ratio is preferably such that the carboxyl group-containing unsaturated monomer (a1) is 0.5 to 20 mass. %, The polyfunctional monomer (a2) is 1 to 70% by mass, the unsaturated monomer (a3) is 10 to 98.5% by mass, and more preferably a carboxyl group-containing unsaturated monomer ( a1) is 1 to 15% by mass, the polyfunctional monomer (a2) is 2 to 60% by mass, and the unsaturated monomer (a3) is 25 to 97% by mass. 3-15% by mass of the saturated monomer (a1), 5-50% by mass of the polyfunctional monomer (a2), unsaturated Mer (a3) is 35 to 92 mass%.

  The copolymer can be produced by a conventionally known polymerization method such as solution polymerization, emulsion polymerization or suspension polymerization. The polymerization conditions such as the polymerization temperature and the polymerization time can be appropriately set according to the characteristics of the copolymer such as the type of monomer to be copolymerized and the molecular weight.

(B) Surfactant The surfactant (B) used in the present invention is preferably an anionic surfactant or a nonionic surfactant.

  Examples of the anionic surfactant include alkyl sulfates such as lauryl sulfate; alkylbenzene sulfonic acids such as dodecylbenzene sulfonic acid; alkyl naphthalene sulfonic acids; sulfates of polyoxyethylene alkyl ethers such as polyoxyethylene lauryl sulfate; naphthalene Examples thereof include sulfonic acid condensates; polymers of unsaturated carboxylic acids such as poly (meth) acrylic acid and acrylic acid-methacrylic acid copolymers; lignin sulfonic acid and the like. These anionic surfactants may be used in the form of a salt. In this case, examples of the counter cation include sodium ion, potassium ion, and ammonium ion. Of these, potassium ions and ammonium ions are preferred.

  Examples of nonionic surfactants include polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether, polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octylphenyl ether, polyoxy Polyoxyethylene aryl ethers such as ethylene nonylphenyl ether; sorbitan fatty acid esters such as sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate; polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxy And polyoxyethylene sorbitan fatty acid esters such as ethylene sorbitan monostearate.

The said surfactant can be used individually by 1 type or in mixture of 2 or more types. Of the above surfactants (B), alkyl sulfates, alkylbenzene sulfonic acids, alkyl naphthalene sulfonic acids and polyoxyethylene alkyl ethers are preferred. Ammonium lauryl sulfate, dodecyl benzene sulfonic acid, potassium dodecyl benzene sulfonate, potassium alkyl naphthalene sulfonate And polyoxyethylene lauryl ether is more preferred.

  The cleaning composition according to the present invention includes, in addition to the crosslinked organic polymer particles (A) and the surfactant (B), an organic acid (C), a complexing agent (D), and the like as necessary. The component may be contained. Further, in the cleaning composition according to the present invention, the above components are preferably dissolved or dispersed in a suitable solvent.

(C) Organic acid The organic acid (C) used in the present invention ionizes metals, particularly copper, metal oxides, particularly copper oxides, and promotes the formation of ionic compounds that are soluble in the solvent described below. To play a role.

  Such an organic acid (C) is preferably a compound having at least one carboxyl group. However, when a nitrogen atom is contained in the molecule of the organic acid (C), it is preferable that a carboxyl group is not bonded to the nitrogen atom. This organic acid (C) may further have a hydroxyl group and / or an amino group.

  Examples of such organic acid (C) include monocarboxylic acids such as formic acid, acetic acid, propionic acid; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, maleic acid, fumaric acid, phthalate Dicarboxylic acids such as acids; tricarboxylic acids such as trimellitic acid and tricarballylic acid; oxymonocarboxylic acids (eg, hydroxybutyric acid, lactic acid, salicylic acid), oxydicarboxylic acids (eg, malic acid, tartaric acid), oxytricarboxylic acids (eg, And oxycarboxylic acids such as citric acid; and amino acids such as aspartic acid and glutamic acid.

  The said organic acid can be used individually by 1 type or in mixture of 2 or more types. Of the organic acids (C), dicarboxylic acids and oxycarboxylic acids are preferable, and oxalic acid, malonic acid, succinic acid, tartaric acid, and citric acid are more preferable.

(D) Complexing agent The complexing agent (D) used in the present invention is coordinated and stabilized by metal ions and the like (particularly copper ions) solubilized by the action of the cleaning composition according to the present invention, It plays a role in reliably removing the complex formed.

  Examples of the complexing agent (D) include aminopolycarboxylic acids such as ethylenediaminetetraacetic acid [EDTA] and trans-1,2-diaminocyclohexanetetraacetic acid [CyDTA]; ethylenediaminetetra (methylenephosphonic acid) [EDTPO], Phosphonic acids such as ethylenediaminedi (methylenephosphonic acid) [EDDPO], nitrilotris (methylenephosphonic acid) [NTPO], 1-hydroxyethylidene-1,1′-diphosphonic acid [HEDPO]; condensation of tripolyphosphoric acid, hexametaphosphoric acid, etc. Examples thereof include phosphoric acid; diketones such as acetylacetone and hexafluoroacetylacetone; amines such as ethylenediamine and triethanolamine; inorganic ions such as thiocyanate ion, thiosulfate ion and ammonium ion.

  Of the above complexing agents, aminopolycarboxylic acid, phosphonic acid and amine are preferred, and ethylenediaminetetraacetic acid, ethylenediaminetetra (methylenephosphonic acid), nitrilotris (methylenephosphonic acid), ethylenediamine and triethanolamine are more preferred.

(E) Solvent Examples of the solvent used in the present invention include water and a mixed medium of water and alcohol. Examples of the alcohol include methanol, ethanol, isopropanol and the like. Of the above solvents, water is preferably used.

<Cleaning composition>
In the cleaning composition according to the present invention, the content of the crosslinked organic polymer particles (A) is preferably 0.001 to 5.0 mass%, more preferably 0.001 to 1.0 mass%. Yes, and more preferably 0.001 to 0.5 mass%. Moreover, content of surfactant (B) becomes like this. Preferably it is 0.0001-5 mass%, More preferably, it is 0.001-1 mass%, More preferably, it is 0.001-0.5 mass%. It is. When the content of the crosslinked organic polymer particles (A) and the surfactant (B) is in the above range, the crosslinked organic polymer particles (A) are uniformly dispersed to obtain a stable cleaning composition, The effect of removing abrasive grains and metallic foreign matter can be sufficiently exhibited.

  When the cleaning composition according to the present invention contains an organic acid (C), the content thereof is preferably 5% by mass or less, more preferably 0.001 to 1% by mass, and still more preferably 0. 0.001 to 0.5% by mass. When the content of the organic acid (C) is in the above range, the effect of promoting the formation of a soluble ionic compound can be sufficiently exhibited.

  When the cleaning composition of the present invention contains the complexing agent (D), the content thereof is preferably 5% by mass or less, more preferably 0.001 to 3% by mass, and further preferably 0. 0.01 to 3% by mass. When the content of the complexing agent (D) is in the above range, the effect of reliably coordinating to the solubilized metal ion and removing the formed complex can be exhibited.

  The pH of the cleaning composition according to the present invention is preferably 12 or less, more preferably 2 to 11, and further preferably 2 to 6. When the pH is in the above range, sufficient decontamination capability can be exhibited without corroding the metal wiring.

  When the cleaning composition contains an organic acid (C), the pH of the cleaning composition can be controlled by adjusting the amount of the cleaning composition. It can also be controlled by adding an appropriate inorganic acid or basic substance. Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid and the like. Examples of basic substances include hydroxides of alkali metals such as sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, and ammonia. Of these basic substances, ammonia and potassium hydroxide are preferred.

  The cleaning composition according to the present invention only needs to have the concentration of each component in the above preferred range at the time of use. That is, the cleaning composition according to the present invention may be used by directly blending each component so as to be in the preferred concentration range, or a composition in a state of being concentrated from the preferred concentration range is prepared. In addition, a solvent may be added before use to dilute and use each component so that the concentration of each component is within the above preferred range.

A composition in a concentrated state can be prepared by increasing the concentration of each component other than the solvent while maintaining the ratio in the preferred concentration range. In this case, the concentration of the crosslinked organic polymer particles (A) contained in the concentrated composition is preferably 30% by mass or less, more preferably 15% by mass or less, and the concentration of the surfactant (B) is Preferably it is 15 mass% or less, More preferably, it is 10 mass% or less. When the cleaning composition according to the present invention contains an organic acid (C), the concentration of the organic acid (C) contained in the concentrated composition is preferably 15% by mass or less, more preferably 10% by mass. % Or less. When the cleaning composition according to the present invention contains the complexing agent (D), the concentration of the complexing agent (D) contained in the concentrated composition is preferably 15% by mass or less, more preferably 10% by mass. It is as follows. In the concentrated composition, when the concentration of each component is in the above range, the cleaning composition according to the present invention can be stably stored in the concentrated state, and the expected performance can be obtained even when diluted after long-term storage. Can be demonstrated.

[Semiconductor Substrate Cleaning Method and Semiconductor Device Manufacturing Method]
The method for cleaning a semiconductor substrate according to the present invention is a method for cleaning a semiconductor substrate after chemical mechanical polishing using the cleaning composition according to the present invention. The method for manufacturing a semiconductor device according to the present invention includes a step of chemically mechanically polishing a semiconductor substrate and a step of cleaning the semiconductor substrate after the chemical mechanical polishing by the cleaning method according to the present invention.

  As the semiconductor substrate, a semiconductor substrate having at least one material selected from a metal material (hereinafter referred to as “metal wiring material”), a barrier metal, and an insulating material for forming a wiring portion on a surface to be polished. Can be mentioned. Among these, a semiconductor substrate having at least a metal wiring material on the surface to be polished is preferable.

  Examples of the metal wiring material include tungsten, aluminum, copper, and an alloy containing at least one of these metals. Of these, copper and copper-containing alloys are preferred.

  Examples of the barrier metal include tantalum, tantalum nitride, titanium, titanium nitride, and ruthenium. Of these, tantalum and tantalum nitride are preferred.

  Examples of the insulating film include a thermal oxide film, a PETEOS film (Plasma Enhanced-TEOS film), an HDP film (High Density Plasma Enhanced-TEOS film), a silicon oxide film obtained by a thermal CVD method, and a boron phosphorus silicate film (BPSG). Film), an insulating film called FSG, and a low dielectric constant insulating film.

The thermal oxide film can be manufactured by exposing high temperature silicon to an oxidizing atmosphere and chemically reacting silicon and oxygen or silicon and moisture.
The PETEOS film can be manufactured by chemical vapor deposition using tetraethylorthosilicate (TEOS) as a raw material and using plasma as an accelerating condition.

The HDP film can be manufactured by chemical vapor deposition using tetraethylorthosilicate (TEOS) as a raw material and using high-density plasma as a promoting condition.
The silicon oxide film obtained by the thermal CVD method can be manufactured by an atmospheric pressure CVD method (AP-CVD method) or a low pressure CVD method (LP-CVD method).

The boron phosphorus silicate film (BPSG film) can be manufactured by an atmospheric pressure CVD method (AP-CVD method) or a low pressure CVD method (LP-CVD method).
The insulating film called FSG can be manufactured by chemical vapor deposition using high-density plasma as an acceleration condition.

  Examples of the low dielectric constant insulating film include an organic SOG film, a hydrogen-containing SOG film, a low dielectric constant film made of an organic polymer, a SiOF-based low dielectric constant film, and a SiOC-based low dielectric constant film. Here, the “SOG” film is an abbreviation for “Spin On Glass” film, and means an insulating film formed by applying a precursor on a substrate and then forming it by heat treatment or the like.

  The organic SOG film is composed of, for example, a silicon oxide containing an organic group such as a methyl group. Specifically, a precursor containing a mixture of tetraethoxysilane and methyltrimethoxysilane is coated on a substrate. Then, it can be obtained by heat treatment or the like.

  The hydrogen-containing SOG film is composed of a silicon oxide containing a silicon-hydrogen bond. Specifically, the hydrogen-containing SOG film is obtained by applying a precursor containing triethoxysilane or the like on a substrate and then performing a heat treatment or the like. be able to.

  Examples of the low dielectric constant film made of the organic polymer include a low dielectric constant film mainly composed of polyarylene, polyimide, polybenzocyclobutene, polyfluorinated ethylene and the like.

  The SiOF-based low dielectric constant film is made of a silicon oxide containing fluorine atoms, and can be obtained, for example, by adding (doping) fluorine to a silicon oxide film obtained by chemical vapor deposition.

  The SiOC-based low dielectric constant film is composed of a silicon oxide containing carbon atoms, and can be manufactured by, for example, chemical vapor deposition using a mixture of silicon tetrachloride and carbon monoxide as a raw material.

Among the low dielectric constant insulating films, an organic SOG film, a hydrogen-containing SOG film, and a low dielectric constant film made of an organic polymer may have fine pores in the formed film.
The semiconductor substrate used in the method for manufacturing a semiconductor device according to the present invention is not particularly limited as long as it is a semiconductor substrate having the above material (film) on the surface to be polished, but a metal wiring portion is formed on a substrate made of silicon or the like. A semiconductor substrate in which an insulating film having a trench for forming a trench, a barrier metal film on the insulating film, and a metal wiring material deposited on the barrier metal film is preferable. An example of a cross-sectional view of this semiconductor substrate is shown in FIG. A substrate 1 shown in FIG. 1A includes, for example, a base 11 made of silicon, an insulating film 12, a barrier metal film 13, and a metal film 14 forming a wiring portion.

In the method of manufacturing a semiconductor device according to the present invention, first, excess barrier metal and metal wiring material other than the groove are removed by a conventionally known chemical mechanical polishing method.
The chemical mechanical polishing aqueous dispersion used for the chemical mechanical polishing contains abrasive grains, an organic acid, and an oxidizing agent. Furthermore, an inorganic acid or a complexing agent may be included as necessary. The cleaning composition according to the present invention exhibits its effects to the maximum when an abrasive aqueous dispersion containing an inorganic acid or a complexing agent is used.

  Examples of the abrasive grains include inorganic oxides, organic particles, and organic / inorganic composite particles, and silica, ceria, alumina, and organic / inorganic composite particles are preferable. Here, the organic / inorganic composite particles refer to particles in which organic particles and inorganic particles are integrated by electrostatic or chemical action.

  The organic acid is preferably an organic acid having two or more carboxyl groups in one molecule, and examples thereof include oxalic acid, maleic acid, malic acid, succinic acid, and citric acid.

Examples of the oxidizing agent include hydrogen peroxide and ammonium persulfate.
Examples of the inorganic acid include nitric acid and sulfuric acid.

  Examples of the complexing agent include a monocyclic compound having a hetero five-membered ring or a hetero six-membered ring having at least one nitrogen atom; a benzene ring or a naphthalene ring, and a hetero five-membered ring or a hetero ring having at least one nitrogen atom. Examples thereof include compounds having a condensed ring composed of a six-membered ring.

Examples of the monocyclic compound include quinolinic acid and pyridinecarboxylic acid.
The compound having the condensed ring is selected from, for example, quinoline structure, isoquinoline structure, benzotriazole structure, benzimidazole structure, indole structure, isoindole structure, quinazoline structure, cinnoline structure, quinoxaline structure, phthalazine structure and acridine structure. And a compound having a condensed ring structure. Of these, compounds having a quinoline structure, a benzotriazole structure or a benzimidazole structure are preferred. Specific examples of the compound having a condensed ring include quinaldic acid, quinolinol, benzotriazole, benzimidazole, hydroxybenzotriazole, carboxybenzotriazole, and the like.

As the complexing agent used in the present invention, quinolinic acid, quinaldic acid, quinolinol and benzotriazole are preferable.
In the present invention, when removing excess barrier metal and metal wiring material, it is not necessary to use the polishing aqueous dispersion in the entire chemical mechanical polishing process, and the polishing water is preferably used in a part of the polishing process, preferably in the final stage. A system dispersion may be used. As described above, the cleaning composition according to the present invention sufficiently exerts its effect on a semiconductor substrate polished using the polishing aqueous dispersion in a part of the polishing step, preferably in the final stage. be able to.

  In the chemical mechanical polishing step, the semiconductor substrate from which excess barrier metal and metal wiring material have been removed has, for example, a cross section shown in FIG. In many cases, abrasive grains, polishing scraps, metal ions, and the like remain on the insulating film 12 on the polished surface and the metal film 14 forming the wiring portion after polishing (not shown). The semiconductor substrate cleaning method according to the present invention is a method of removing such a residue from the surface of the semiconductor substrate using the cleaning composition.

  The cleaning method according to the present invention can be carried out by conventionally known methods such as surface plate cleaning, brush scrub cleaning, and roll cleaning, except that the cleaning composition according to the present invention is used. In the present invention, the above-described cleaning method may be performed only once, but may be performed twice or more. When washing twice or more, the same method may be repeated or different methods may be combined. Further, the cleaning method according to the present invention using the cleaning composition according to the present invention may be combined with a conventionally known cleaning method, for example, a cleaning method using ultrapure water, to perform multiple cleaning. In this case, the order of performing the cleaning method according to the present invention and the conventionally known cleaning method is not limited.

The cleaning conditions can be set as appropriate. For example, in the case of cleaning on a surface plate, the head rotation speed is preferably 10 to 150 rpm, more preferably 20 to 100 rpm, and the head load is preferably 5 to 350 g. / Cm ² , more preferably 10 to 210 g / cm ² , the platen rotational speed is preferably 10 to 150 rpm, more preferably 20 to 100 rpm, and the cleaning composition supply rate is preferably 50 to 400 mL / min. More preferably, it is 100 to 300 mL / min, and the washing time is preferably 5 to 120 seconds, more preferably 10 to 100 seconds. In the case of brush scrub cleaning or roll cleaning, generally, the semiconductor substrate is sandwiched between two brushes or rolls, and the number of rotations of the two brushes or rolls may be the same or as required. It is also possible to set different rotational speeds. In addition, although these cleaning conditions are set differently depending on the cleaning device and the cleaning unit, the cleaning conditions in the case of using a general cleaning agent can be applied as they are. For example, the rotational speed of the brush or roll is preferably 10 to 500 rpm, more preferably 30 to 300 rpm, the rotational speed of the substrate is preferably 10 to 300 rpm, more preferably 30 to 200 rpm, and the cleaning composition supply rate is preferable. Is 10 to 500 mL / min, more preferably 50 to 300 mL / min, and the washing time is preferably 5 to 120 seconds, more preferably 10 to 100 seconds.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention, this invention is not limited at all by this Example.

[A] Preparation of cleaning composition (1) Preparation of organic polymer particle-containing aqueous dispersion [Preparation Example A1]
As a monomer, 5 parts by weight of methacrylic acid, 20 parts by weight of divinylbenzene and 75 parts by weight of styrene, 2 parts by weight of ammonium persulfate as a polymerization initiator, 0.1 part by weight of dodecylbenzenesulfonic acid as a surfactant, and as a solvent 400 parts by mass of ion-exchanged water was placed in a flask, heated to 70 ° C. with stirring in a nitrogen atmosphere, and further stirred for 8 hours at the same temperature for polymerization. As a result, an aqueous dispersion containing organic polymer particles (1) having a carboxyl group and a crosslinked structure and having an average dispersed particle diameter of 210 nm (hereinafter referred to as “crosslinked organic polymer particles (1)”) was obtained. Ion exchange water was added to this aqueous dispersion to adjust the content ratio of the crosslinked organic polymer particles (1) to 10% by mass.

[Preparation Example A2]
A carboxyl group and a crosslinked structure were prepared in the same manner as in Preparation Example A1, except that 5 parts by weight of methacrylic acid, 10 parts by weight of trimethylolpropane triacrylate, 35 parts by weight of styrene and 50 parts by weight of methyl methacrylate were used as monomers. A water dispersion containing organic polymer particles (2) (hereinafter referred to as “crosslinked organic polymer particles (2)”) having an average dispersed particle diameter of 190 nm was obtained. Ion-exchanged water was added to the water dispersion. In addition, the content ratio of the crosslinked organic polymer particles (2) was adjusted to 10% by mass.

[Preparation Example A3]
Except for using 5 parts by weight of acrylic acid, 10 parts by weight of divinylbenzene, 45 parts by weight of styrene and 40 parts by weight of methyl methacrylate as the monomer, it has a carboxyl group and a crosslinked structure in the same manner as in Preparation Example A1, An aqueous dispersion containing organic polymer particles (3) having an average dispersed particle size of 250 nm (hereinafter referred to as “crosslinked organic polymer particles (3)” was obtained. Ion-exchanged water was added to the aqueous dispersion, The content ratio of the crosslinked organic polymer particles (3) was adjusted to 10% by mass.

[Preparation Example A4]
Similar to Preparation Example A1 except that 5 parts by weight of methacrylic acid and 95 parts by weight of styrene were used as monomers. An aqueous dispersion containing polymer particles (a) (hereinafter referred to as “non-crosslinked organic polymer particles (a)” was obtained. By adding ion-exchanged water to the aqueous dispersion, non-crosslinked organic polymer particles (a ) Was adjusted to 10% by mass.

  Table 1 shows the monomers used in Preparation Examples A1 to A4.

(2) Preparation of cleaning composition (2-1) Preparation of cleaning compositions (1) to (3) Prepared in the above preparation example containing crosslinked organic polymer particles shown in Table 2 in a polyethylene container. The obtained water dispersion was charged with the amounts shown in Table 2 in terms of crosslinked organic polymer particles and the types and amounts of surfactants shown in Table 2 and stirred for 15 minutes. After adding ion-exchange water to this mixture so that the total amount of all the structural components may be 100 mass parts, it filtered with the filter of the hole diameter of 5 micrometers, and obtained the cleaning compositions (1)-(3). The pH of these compositions is shown in Table 2.

(2-2) Preparation of cleaning compositions (4) to (6) A water-dispersed polymer prepared in the above-mentioned preparation example containing the crosslinked organic polymer particles shown in Table 2 in a polyethylene container is crosslinked organic polymer. The amounts shown in Table 2 in terms of particles, the types and amounts of surfactants shown in Table 2, and the types and amounts of organic acids shown in Table 2 were added and stirred for 15 minutes. After adding ion-exchange water to this mixture so that the total amount of all the structural components might be 100 mass parts, it filtered with the filter of the hole diameter of 5 micrometers, and obtained the cleaning compositions (4)-(6). The pH of these compositions is shown in Table 2.

(2-3) Preparation of cleaning compositions (7) to (10) A crosslinked organic polymer prepared by the above preparation example containing the crosslinked organic polymer particles shown in Table 2 in a polyethylene container. The amounts shown in Table 2 in terms of particles, the types and amounts of surfactants shown in Table 2, the types and amounts of organic acids shown in Table 2, and the types and amounts of complexing agents shown in Table 2 are added. And stirred for 15 minutes. After adding ion-exchange water to this mixture so that the total amount of all the structural components might be 100 mass parts, it filtered with the filter of the hole diameter of 5 micrometers, and obtained the cleaning compositions (7)-(10). The pH of these compositions is shown in Table 2.

(2-4) Preparation of cleaning composition (11) A polyethylene container was charged with 0.02 parts by weight of dodecylbenzenesulfonic acid as a surfactant and 0.4 parts by weight of citric acid as an organic acid. Stir for minutes. After adding ion-exchange water to this mixture so that the total amount of all the structural components might be 100 mass parts, it filtered with the filter of the hole diameter of 5 micrometers, and obtained the composition (11) for washing | cleaning. The pH of this composition is shown in Table 2.

(2-5) Preparation of Cleaning Composition (12) The aqueous dispersion prepared in Preparation Example A4 above, containing non-crosslinked organic polymer particles (a) in a polyethylene container, is converted into non-crosslinked organic polymer particles. Were charged with 0.10 parts by mass, 0.02 parts by mass of dodecylbenzenesulfonic acid as a surfactant, and 0.2 parts by mass of citric acid as an organic acid, and stirred for 15 minutes. After adding ion-exchange water to this mixture so that the total amount of all the structural components might be 100 mass parts, it filtered with the filter of the hole diameter of 5 micrometers, and obtained the composition (12) for washing | cleaning. The pH of this composition is shown in Table 2.

[B] Preparation of chemical mechanical polishing aqueous dispersion (1) Preparation of abrasive-containing dispersion [Preparation Example B1]
(Preparation of aqueous dispersion containing colloidal silica (1))
70 parts by mass of ammonia water having a concentration of 25% by mass, 40 parts by mass of ion-exchanged water, 170 parts by mass of ethanol, and 20 parts by mass of tetraethoxysilane were put into a rotary dispersing device, and the temperature was raised to 60 ° C. while rotating and stirring at 180 rpm. The mixture was further stirred at 60 ° C. for 2 hours. Next, after cooling to room temperature, using a rotary evaporator, the operation of removing ethanol while adding ion-exchanged water at 80 ° C. is repeated several times to obtain an aqueous dispersion containing 20% by mass of colloidal silica (1). Got. The average primary particle diameter of the colloidal silica (1) contained in this aqueous dispersion was 25 nm, and the average secondary particle diameter was 40 nm.

[Preparation Example B2]
(Preparation of aqueous dispersion containing colloidal silica (2))
Colloidal silica (2) was prepared in the same manner as in Adjustment Example B1, except that the amount of ethanol used was changed from 170 parts by weight to 190 parts by weight, and the amount of tetraethoxysilane used was changed from 20 parts by weight to 35 parts by weight. An aqueous dispersion containing 20% by mass was obtained. The colloidal silica (2) contained in this aqueous dispersion had an average primary particle size of 50 nm and an average secondary particle size of 75 nm.

[Preparation Example B3]
(Preparation of aqueous dispersion containing fumed alumina)
2 kg of fumed alumina particles (trade name “Aluminum Oxide C”, manufactured by Degussa Co., Ltd.) are charged into 6.7 kg of ion-exchanged water, dispersed by an ultrasonic disperser, and filtered through a filter having a pore size of 5 μm. An aqueous dispersion containing alumina was obtained. The average dispersed particle diameter of alumina contained in this aqueous dispersion was 150 nm.

[Preparation Example B4]
(Preparation of aqueous dispersion containing fumed silica)
Put 6 kg of ion-exchanged water into the planetary kneader “TK Hibis Disper Mix 3D-20” (manufactured by Tokushu Kika Kogyo Co., Ltd.) and rotate the twisting blade at 10 rpm and 30 rpm. 6 kg of fumed silica particles (produced by Nippon Aerosil Co., Ltd., trade name “Aerosil # 50”, specific surface area measured by BET (Brunauer-Emmett-Teller) method: 52 m ² / g) over 30 minutes. Added to. Thereafter, the twist blade was rotated at a main rotation of 10 rpm and a sub rotation of 30 rpm, and a coreless high-speed rotary blade having a diameter of 80 mm was kneaded for 1 hour while rotating at a main rotation of 10 rpm and a sub rotation of 2,000 rpm.

  Next, 0.3108 g of a 20% by mass potassium hydroxide aqueous solution was added to the obtained mixture, and further diluted with ion-exchanged water, and then filtered through a depth cartridge filter having a pore size of 5 μm to contain 30% by mass of fumed silica. An aqueous dispersion was obtained. The average dispersed particle diameter of silica contained in this aqueous dispersion was 52 nm.

[Preparation Example B5]
(Preparation of aqueous dispersion containing organic abrasive grains (1))
As a monomer, 85 parts by weight of methyl methacrylate, 10 parts by weight of styrene and 5 parts by weight of acrylic acid, 2 parts by weight of ammonium persulfate as a polymerization initiator, 0.1 part by weight of dodecylbenzenesulfonic acid as a surfactant, and as a solvent 400 parts of ion-exchanged water was charged into a flask, heated to 70 ° C. with stirring in a nitrogen atmosphere, and then held at 80 ° C. for 8 hours to polymerize to a polymerization conversion rate of 100%. This was diluted with ion-exchanged water to obtain an aqueous dispersion containing 10% by mass of organic abrasive grains (1) having an average dispersed particle diameter of 150 nm.

[Preparation Example B6]
(Preparation of aqueous dispersion containing organic abrasive (2))
10% by weight of organic abrasive grains (2) having an average dispersed particle diameter of 190 nm were prepared in the same manner as in Preparation Example B5 except that 4 parts by weight of methacrylic acid, 91 parts by weight of styrene and 5 parts by weight of divinylbenzene were used as monomers. An aqueous dispersion containing was obtained.

(2) Preparation of chemical mechanical polishing aqueous dispersions (1) to (10) The aqueous dispersion prepared in the above preparation example containing abrasive grains shown in Table 3 in a polyethylene container is converted into abrasive grains in Table 3. , The types and amounts of organic acids shown in Table 3, the types and amounts of complexing agents shown in Table 3, and the types and amounts of oxidizing agents shown in Table 3 were added in that order and stirred for 15 minutes. . To this mixture, the pH adjusting agent shown in Table 3 was added so that the pH of the finally obtained chemical mechanical polishing aqueous dispersion would be the value shown in Table 3, and the total amount of all the constituent components was 100 mass. After adding ion-exchanged water so as to be part, it was filtered through a filter having a pore diameter of 5 μm to obtain chemical mechanical polishing aqueous dispersions (1) to (10). The pH of these polishing aqueous dispersions is shown in Table 3.

  In addition, in the aqueous dispersions for polishing (5), (7) and (8), fumed silica or colloidal silica and organic abrasive grains were used in combination.

[C] Production of low dielectric constant insulating film (1) Preparation of polysiloxane sol 101.5 g of methyltrimethoxysilane, 276.8 g of methyl methoxypropionate and 9.7 g of tetraisopropoxytitanium / ethyl acetoacetate complex were mixed, After raising the temperature to 60 ° C., a mixture of 92.2 g of γ-butyrolactone and 20.1 g of water was added dropwise over 1 hour with stirring. After completion of dropping, the mixture was further stirred at 60 ° C. for 1 hour to obtain a polysiloxane sol.

(2) Preparation of polystyrene particles 100 parts by mass of styrene, 2 parts by mass of an azo polymerization initiator (trade name “V60” manufactured by Wako Pure Chemical Industries, Ltd.), 0.5 parts by mass of potassium dodecylbenzenesulfonate and ion-exchanged water 400 parts by mass were charged into a flask, heated to 70 ° C. with stirring in a nitrogen gas atmosphere, and polymerized at this temperature for 6 hours. Thereby, polystyrene particles having an average particle diameter of 150 nm were obtained.

(3) Production of low dielectric constant insulating film 15 g of the polysiloxane sol obtained in (3-1) above and 1 g of the polystyrene particles obtained in (3-2) above were mixed, and the resulting mixture was It apply | coated by the spin coat method on the silicon substrate with a thermal oxide film of 8 inches in diameter. This was heated in an oven at 80 ° C. for 5 minutes, followed by heating at 200 ° C. for 5 minutes. Thereafter, in a vacuum, heating is performed at 340 ° C. for 30 minutes, then at 360 ° C. for 30 minutes, then at 380 ° C. for 30 minutes, and further heated at 450 ° C. for 1 hour, whereby a colorless transparent film having a thickness of 2000 mm (low dielectric constant) A substrate having a dielectric constant insulating film) was manufactured. When the cross section of this film was observed with a scanning electron microscope, it was confirmed that many fine pores were formed. Further, this film had a relative dielectric constant of 1.98, an elastic modulus of 3 GPa, and a porosity of 15%.

[D] Preparation of metal-contaminated substrate Copper nitrate was dissolved in ultrapure water to prepare a solution containing copper ions at a concentration of 100 ppb. An 8-inch p-type silicon wafer (manufactured by Shin-Etsu Semiconductor Co., Ltd.) was immersed in this solution at 25 ° C. for 30 minutes and dried with a spin dryer to prepare a substrate contaminated with metal.

When the amount of metal contamination of this substrate was quantified by a total reflection fluorescent X-ray method using “TREX610T” manufactured by Technos Co., Ltd., copper atoms adhered to 2 × 10 ¹³ atoms / cm ² .
[Example 1]
(1) Chemical Mechanical Polishing and Cleaning of Insulating Film (1-1) Chemical Mechanical Polishing The insulating film surface of the substrate having the low dielectric constant insulating film prepared in [C] above is subjected to a chemical mechanical polishing apparatus “EPO112” Chemical mechanical polishing was performed under the following conditions.
(Polishing conditions)
Chemical mechanical polishing aqueous dispersion: Polishing aqueous dispersion (1)
Polishing pad: Rodel Nitta Co., Ltd., “IC1000 / SUBA400”
Head rotation speed: 70rpm
Head load: 250 g / cm ²
Plate rotation speed: 70rpm
Polishing aqueous dispersion supply rate: 300 mL / min Polishing time: 60 seconds (1-2) Cleaning of insulating film Subsequent to chemical mechanical polishing in (1-1) above, the substrate surface after polishing is subjected to the following conditions: Then, it was washed on a surface plate and further washed with a brush scrub. Hereinafter, this is referred to as “two-stage cleaning”.
(Washing on the surface plate)
Detergent: Cleaning composition (1)
Head rotation speed: 70rpm
Head load: 100 g / cm ²
Plate rotation speed: 70rpm
Cleaning agent supply amount: 300 mL / min Cleaning time: 30 seconds (brush scrub cleaning)
Detergent: Cleaning composition (11)
Upper brush rotation speed: 100rpm
Lower brush rotation speed: 100rpm
Substrate rotation speed: 100 rpm
Cleaning agent supply amount: 300 mL / min Cleaning time: 60 seconds (1-3) Evaluation of polishing rate and surface defects Optical interference measuring instrument “FPT500” (SENTEC) for substrates before chemical mechanical polishing and after the above cleaning The film thickness of the insulating film was measured using the product, and the polishing rate was calculated from the difference and the polishing time, which was 1,200 Å / min. Further, when the entire surface of the insulating film after cleaning was observed using a wafer surface foreign matter inspection apparatus “Surfscan SP1” (manufactured by KLA Tencor), the number of surface defects was 8 / surface. Here, “surface defects” include remaining abrasive grains, watermarks (the cause of generation is unknown, but a substantially circular discoloration such as “stain”), and the like.

(2) Cleaning of Metal-Contaminated Substrate The substrate contaminated with metal produced in [D] above is subjected to the above-mentioned “(1-2) Insulation using a chemical mechanical polishing apparatus“ EPO112 ”(manufactured by Ebara Corporation). The membrane was washed twice in the same manner as in “Membrane washing”.

When the amount of metal contamination of the substrate after cleaning was quantified by a total reflection fluorescent X-ray method using “TREX610T” manufactured by Technos Co., Ltd., the residual amount of copper atoms was 5 × 10 ¹¹ atoms / cm ² . .

[Examples 2 to 13 and Comparative Examples 1 to 7]
(1) Cleaning of insulating film after chemical mechanical polishing (1-1) Chemical mechanical polishing Except for using chemical mechanical polishing aqueous dispersion shown in Table 4 instead of chemical mechanical polishing aqueous dispersion (1) In the same manner as in Example 1, the surface of the insulating film of the substrate having the low dielectric constant insulating film prepared in [C] was subjected to chemical mechanical polishing.

(1-2) Insulating film cleaning In the same manner as in Example 1 except that the cleaning agents described in Table 4 were used instead of the cleaning compositions (1) and (11), the above (1-1) Following the chemical mechanical polishing, the polished substrate surface was washed twice.

(1-3) Evaluation of polishing rate and surface defects The polishing rate of the insulating film and the number of surface defects after cleaning were evaluated in the same manner as in Example 1. The results are shown in Table 4.

(2) Cleaning of metal-contaminated substrate It was prepared in [D] in the same manner as in Example 1 except that the cleaning agents described in Table 4 were used instead of the cleaning compositions (1) and (11). The substrate contaminated with metal was washed twice.

[Example 14]
(1) Chemical mechanical polishing and cleaning of patterned substrate (1-1) Chemical mechanical polishing A substrate with a pattern of copper wiring (made by International SEMATECH, model number: 854LKD003) is a chemical mechanical polishing apparatus "EPO112" (Ebara Corporation) And two-stage chemical mechanical polishing was performed under the following conditions.
(1st stage chemical mechanical polishing)
Chemical mechanical polishing aqueous dispersion: Polishing aqueous dispersion (5)
Polishing pad: Rodel Nitta Co., Ltd., “IC1000 / SUBA400”
Plate rotation speed: 70 rpm
Head rotation speed: 70rpm
Head load: 250 g / cm ²
Polishing aqueous dispersion supply rate: 300 mL / min Polishing time: 150 seconds (second stage chemical mechanical polishing)
Chemical mechanical polishing aqueous dispersion: polishing aqueous dispersion (9)
Plate rotation speed: 70rpm
Head rotation speed: 70rpm
Head load: 250 g / cm ²
Abrasive aqueous dispersion supply rate: 300 mL / min Polishing time: 45 seconds (1-2) Cleaning Subsequent to chemical mechanical polishing in (1-1) above, the substrate surface after polishing is subjected to a surface plate under the following conditions. The top was washed and further brush scrub washed.
(Washing on the surface plate)
Cleaning agent: Cleaning composition (7)
Head rotation speed: 70rpm
Head load: 100 g / cm ²
Plate rotation speed: 70rpm
Cleaning agent supply rate: 300 mL / min Cleaning time: 30 seconds (brush scrub cleaning)
Cleaning agent: Cleaning composition (7)
Upper brush rotation speed: 100rpm
Lower brush rotation speed: 100rpm
Substrate rotation speed: 100 rpm
Cleaning agent supply amount: 300 mL / min Cleaning time: 60 seconds (1-3) Evaluation of polishing rate and surface defects The entire surface of the substrate after cleaning is subjected to a wafer surface foreign matter inspection apparatus “Surf Scan SP1” (KLA Tencor Corporation) The number of surface defects was 8 / surface. In addition, the dishing of the portion with a wiring width of 100 μm on the substrate was measured using a high-resolution level difference measuring device “HRP240” (manufactured by KLA Tencor Co., Ltd.) and found to be 310 mm.

[Comparative Example 8]
A substrate with a copper wiring pattern (as in Example 14), except that ultrapure water was used as the cleaning agent for cleaning on the surface plate and the cleaning composition (11) was used as the cleaning agent for brush scrub cleaning. 854LKD003) was subjected to two-stage chemical mechanical polishing and then two-stage cleaning. When the entire surface of the substrate after cleaning was observed in the same manner as in Example 14, the number of surface defects was 162 / surface. Further, the dishing at the wiring width 100 μm portion on the substrate was 310 mm.

  From the results of Examples 1 to 13 and Comparative Examples 1 to 7, in the cleaning using only the conventionally known cleaning agents (Comparative Examples 1 to 7), although the ability to remove impure metal ions on the substrate is excellent, While surface defects occur, cleaning (Examples 1 to 13) using the cleaning composition according to the present invention can maintain or improve the ability to remove impure metal ions of a conventionally known cleaning agent, It was found that the occurrence of surface defects can also be suppressed.

  Further, from the results of Example 14 and Comparative Example 8, when the patterned substrate after chemical mechanical polishing is cleaned using only a conventionally known cleaning agent, many surface defects are observed. It has been found that when the cleaning composition according to the present invention is used for cleaning, the occurrence of surface defects can be suppressed without adversely affecting the metal wiring portion.

FIG. 1 is a cross-sectional view showing an example of a semiconductor substrate used in the present invention. (A) is sectional drawing which shows an example of the semiconductor substrate before chemical mechanical polishing. (B) is sectional drawing which shows an example of the semiconductor substrate before washing | cleaning.

Explanation of symbols

1 Semiconductor substrate material 11 Base (for example, made of silicon)
12 Insulating film (for example, made by PETEOS)
13 Barrier metal film 14 Metal film

Claims (7)

  A cleaning composition for use after chemical mechanical polishing, comprising organic polymer particles (A) having a crosslinked structure and a surfactant (B). The organic polymer particles (A) having a crosslinked structure are a carboxyl group, a hydroxyl group, an amino group, a sulfonic acid group, and —N ⁺ R ₃ (wherein R represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). The cleaning composition according to claim 1, which has at least one functional group selected from the group consisting of:   The cleaning composition according to claim 1, wherein the organic polymer particles (A) having a crosslinked structure have an average dispersed particle diameter of 120 to 500 nm.   The organic polymer particles (A) having a crosslinked structure are other than the carboxyl group-containing unsaturated monomer (a1), the polyfunctional monomer (a2), and the monomers (a1) and (a2). The cleaning composition according to claim 1, wherein the composition is a particle made of a copolymer with an unsaturated monomer (a3).   A method for cleaning a semiconductor substrate, comprising: cleaning the semiconductor substrate after chemical mechanical polishing using the cleaning composition according to claim 1.   6. The cleaning method according to claim 5, wherein the cleaning is at least one cleaning selected from the group consisting of cleaning on a surface plate, brush scrub cleaning, and roll cleaning. A method for manufacturing a semiconductor device, comprising: a step of chemical mechanical polishing a semiconductor substrate; and a step of cleaning the semiconductor substrate after chemical mechanical polishing by the cleaning method according to claim 5.

Images