JP2001284308A - Cleaning fluid and method of substrate for semiconductor device having transition metal or transition metal compound on surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an industrially useful cleaning fluid and method that can achieve a clean substrate surface, without contamination or corroding a metal member made of transition metal such as tungsten and copper, existing on the surface of a substrate for manufacturing a semiconductor device or a transition metal compound, and without applying any ultrasonic waves. SOLUTION: This cleaning fluid for the substrate for a semiconductor device, having the transition metal or transition metal compound on the surface, is composed by a solution that is selected from among a group consisting of (A1), (A2), and (A3). In this case, (A1) is a solution including a surface-active agent, having an -SO3- group (excluding sulfosuccinic acid diester compound) while pH should be set to 3 or lower, (A2) is a solution including the surface-active agent that is made of a methyl taurine acid compound, and (A3) is a solution including the surface-active agent, having an -OSO3- group and/or the surface-active agent that is made of a methyl taurine acid compound, while the pH should be set to 4 or higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a cleaning solution and a cleaning method for a semiconductor device substrate having a transition metal or a transition metal compound, particularly tungsten or copper, on the surface.

[0002]

2. Description of the Related Art With the high performance and high integration of various devices represented by LSIs and TFT flat panel displays, the surface of a substrate used for the devices has been required to be further cleaned. ing. Among the contamination on the substrate surface, in particular, contamination by metal and contamination by particles reduce the electrical characteristics and yield of the device. Therefore, it is required to remove metal and particles as much as possible. Generally, the surface of a substrate is cleaned with a cleaning liquid in order to remove metals and particles from the surface of the substrate.

Conventionally, in order to clean the surface of a substrate, a cleaning process using a cleaning solution obtained by mixing an acidic or alkaline solution and hydrogen peroxide (hereinafter, may be referred to as “RCA cleaning” (for example, RCA Review (1970.6) ), pp. 207 to 233)). In the RCA cleaning, cleaning is performed by selecting a cleaning liquid according to a contaminant on the substrate surface. For example, for contamination by particles on the substrate surface or contamination by organic substances, “SC-1” or “SC” is used. AP
Cleaning is performed with a cleaning liquid called "M", which is composed of ammonia, hydrogen peroxide and water. "SC-2" or "HPM" for metal contamination on the substrate surface
Cleaning with a cleaning solution called hydrochloric acid, hydrogen peroxide and water is performed. In addition, for contamination of photoresist and resist residue on the substrate surface, “SP
Cleaning with a cleaning solution called sulfuric acid and hydrogen peroxide called "M" is performed.

On the other hand, in order to improve the performance of a semiconductor device such as a transistor, reduction in resistance of a gate electrode and a wiring material constituting the semiconductor device has been studied. Conventionally,
The material of the gate electrode is mainly polysilicon or WSi
(Tungsten silicide), CoSi (cobalt silicide), TiSi (titanium silicide), and the like are used. However, use of a metal material as a gate material has been studied to reduce resistance. As such a metal material, attention is paid to W (tungsten) and Cu (copper).

The material of the gate electrode is polysilicon, WS
In the case of i, CoSi, TiSi, or the like, the above-described cleaning using a cleaning solution containing hydrogen peroxide (RCA cleaning) can be applied to cleaning after forming the gate electrode on the substrate. But,
When the gate electrode material is a metal such as tungsten, RC
The problem that the electrode material is corroded when A cleaning is performed has been found. As a result of the analysis, it has been clarified that the cause is that hydrogen peroxide in the cleaning solution used for RCA cleaning ionizes and dissolves tungsten.

As described above, in order to achieve high performance of a semiconductor device, a metal electrode such as tungsten is newly introduced as a gate electrode material of the semiconductor device, and copper or tungsten is newly added as a wiring material of the semiconductor device. Etc. are beginning to be introduced. However, at present, a cleaning liquid satisfying the following three requirements has not been found as a cleaning liquid for a substrate having these electrodes and wirings formed on the surface. It does not corrode electrodes and wiring of tungsten, copper, etc., has excellent removal of particle contamination on the substrate surface, has excellent removal of metal contamination on the substrate surface,

[0007]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and is intended for cleaning a substrate having a transition metal or a transition metal compound such as tungsten or copper on a surface thereof partially or entirely. In order to provide a cleaning solution and a cleaning method that satisfy the two requirements of not corroding such metal and being excellent in removing particle contamination on the substrate surface, more preferably, being excellent in removing metal contamination on the substrate surface. It is an object of the present invention to provide a cleaning solution and a cleaning method that simultaneously satisfy the three requirements.

Further, in order to achieve higher performance (higher density) of a semiconductor device, a technique of miniaturizing a pattern of the semiconductor device or increasing an aspect ratio (ratio of height to width of the pattern) of the pattern is used. Is used. In such a pattern, there is a problem that the pattern collapses due to irradiation of ultrasonic waves. There is a need for a cleaning solution that can be cleaned without ultrasonic irradiation.

[0009]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, it has been found that the above-mentioned problems can be satisfied by using a specific solution containing a specific surfactant as a cleaning solution. And arrived at the present invention. That is, the gist of the present invention is a cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on the surface, the cleaning solution comprising a solution selected from the group consisting of the following (A1), (A2) and (A3). A cleaning liquid for a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof, and a method for cleaning a semiconductor device substrate having a transition metal or a transition metal compound on a surface comprising using the cleaning liquid. Exist. (A1) -SO ₃ - surfactant having a group (excluding sulfosuccinic acid diester compound) comprises, pH
Comprise surfactants consisting of surfactants and / or sulfosuccinic acid diester compound having a group - solution (A3) -OSO ₃ comprising a surfactant but consisting of 3 or less solution (A2) methyl taurine acid compound , A solution having a pH of 4 or more

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The cleaning solution of the present invention comprises the following (A1) and (A1)
It consists of one or more solutions selected from the group consisting of 2) and (A3). (A1) -SO ₃ - surfactant having a group (excluding sulfosuccinic acid diester compound) comprises, pH
Comprise surfactants consisting of surfactants and / or sulfosuccinic acid diester compound having a group - solution (A3) -OSO ₃ comprising a surfactant but consisting of 3 or less solution (A2) methyl taurine acid compound the solution pH is 4 or more first, - to Shoki for "(A1) -SO ₃ surfactant having a group (excluding sulfosuccinic acid diester compound), with the solution pH is 3 or less" . -S
The surfactant having an O ₃ -group is as follows:
The compound of.

Alkyl sulfonic acid compound The alkyl sulfonic acid compound is represented by the following formula (1).
Compounds to be used. RSO_ThreeX: Formula (1) (wherein, R is an alkyl group, preferably having 8 to 20 carbon atoms)
An alkyl group, X is hydrogen, a cation atom or a cation atom;
Indicates a gang. ) Alkyl sulfonic acids include, for example, C₈H₁₇SO_Three
H and its salts, C₉H_{1 9}SO_ThreeH and its salts, C_TenH_{twenty one}S
O_ThreeH and its salts, C₁₁H_{twenty three}SO_ThreeH and its salts, C₁₂H
_{twenty five}SO_ThreeH and its salts, C₁₃H₂₇SO_ThreeH and its salts, C
₁₄H₂₉SO_ThreeH and its salts, C_FifteenH₃₁SO_ThreeH and its
Salt, C₁₆H₃₃SO_ThreeH and its salts, C₁₇H ₃₅SO_ThreeH and
Its salt, C₁₈H₃₇SO_ThreeH and its salts, etc.
You.

Alkylbenzenesulfonic acid-based compound The alkylbenzenesulfonic acid-based compound includes a compound represented by the following formula (2). R-ph-SO ₃ X ··· Equation (2) (wherein, R is an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, X is hydrogen, a cation atom or a cation atomic group, ph is a phenylene group Shown.) Examples of the alkylbenzene sulfonic acids include dodecylbenzene sulfonic acid and salts thereof.

Alkyl naphthalene sulfonic acid compound The alkyl group constituting the alkyl naphthalene sulfonic acid includes a compound represented by the following formula (3).

[0015]

Embedded image

(Wherein R ¹ and R ² are each an alkyl group,
Preferably, an alkyl group having 8 to 20 carbon atoms, X represents hydrogen, a cation atom or a cation atom group. m and n each represent an integer of 0 to 4. However, 1 ≦ m + n ≦ 7, preferably 1 ≦ m + n ≦ 4. Examples of the alkylnaphthalenesulfonic acids include dimethylnaphthalenesulfonic acid and salts thereof.

Methyltauric acid compound The methyltauric acid compound is represented by the following formula (4).
Compounds. RCON (CH_Three) CH_TwoCH_TwoSO_ThreeX: Formula (4) (wherein, R is a hydrocarbon group, preferably C_nH_{2n + 1}, C_n
H_2n-1, C_nH_2n-3Or C_nH_2n-5Saturated or unsaturated
X is hydrogen, a cation atom or a cation
Indicates an atomic group. n is usually 8 to 20, preferably 13 to
Represents an integer of 17. N, which is the number of carbon atoms in the hydrocarbon group, is small
If it is too much, the ability to remove adhered particles tends to decrease. Examples of the methyltauric acid-based compound include C₁₁H_{twenty three}
CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and its salts, C₁₃H
₂₇CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and its salts, C_Fifteen
H₃₁CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and its salts, C
₁₇H₃₅CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and its salts,
C₁₇H₃₃CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and its
Salt, C₁₇H₃₁CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and that
Salt, C_{1 7}H₂₉CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and
And salts thereof.

Alkyl diphenyl ether disulfonic acid compound The alkyl diphenyl ether disulfonic acid compound includes a compound represented by the following formula (5). _{R-ph (SO 3 X)} -O-ph-SO 3 X ··· Equation (5) (wherein, R is an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, X is hydrogen, a cation atom or The cationic group, ph represents a phenylene group.) As the alkyl diphenyl ether disulfonic acids,
For example, nonyl diphenyl ether disulfonic acid and its salt, dodecyl diphenyl ether disulfonic acid and its salt, etc. are mentioned.

Α-Olefin Sulfonic Acid Compound The α-olefin sulfonic acid compound includes a mixture of a compound represented by the following formula (6) and a compound represented by the following formula (7). RCH = CH (CH ₂ ) _m SO ₃ X Formula (6) RCH ₂ CH (OH) (CH ₂ ) _n SO ₃ X Formula (7) (where R is an alkyl group, preferably An alkyl group having 4 to 20 carbon atoms, X represents hydrogen, a cation atom or a cation atom group, m represents an integer of 1 to 10, and n represents 1 to 10
Represents an integer. )

Naphthalenesulfonic acid condensate Examples of the naphthalenesulfonic acid condensate include β-naphthalenesulfonic acid formalin condensate and salts thereof. A fluorine-based surfactant in which the hydrogen of the alkyl group or the hydrocarbon group of the surfactant represented by the above is replaced by fluorine

Of these surfactants, a methyltauric acid-based compound, an alkylbenzenesulfonic acid-based compound,
Alkyl diphenyl ether disulfonic acid compounds are used. Furthermore, when the pH of the cleaning solution is neutral,
An alkylbenzenesulfonic acid-based compound and an alkyldiphenyletherdisulfonic acid-based compound are particularly preferably used in that the particle contamination is excellent when the pH is 3 or less. Further, even under the condition that the pH of the cleaning solution is 3 or less, a methyltauric acid-based compound is preferably used in that it has the same high particle removal properties as when the pH is neutral and has little bubbling.

The sulfosuccinic acid diester compound
Is represented by the following formula (8): _Three-Interfaces with groups
As an activator, in acidic solutions, the cleaning ability
Has been removed. This is sulfosuccinic acid di
Esters are -SO_Three-Having an ester structure
It is presumed that decomposition occurs in acidic solution
It is.

[0023]

Embedded image

(Wherein, R is an alkyl group optionally substituted by a fluorine atom, preferably an alkyl group having 4 to 20 carbon atoms optionally substituted by a fluorine atom, and X is hydrogen, a cation atom or a cation atom. The solution containing a surfactant having an —SO ₃ — group (excluding a sulfosuccinic acid diester compound) has a pH of 3 or less, preferably pH 2 or less, and more preferably pH.
The pH is 1.5 or less, particularly preferably the pH is 1.0 or less.
If the pH is too high, the ability to remove metal contamination will decrease. Also,
Alkyl benzene sulfonic acids and alkyl diphenyl ether disulfonic acids are not preferred because the particle removal performance is also reduced.

It is known that when an acid is added to a cleaning solution to lower the pH, the removability of particle contamination generally decreases (Itano et al., IEEE Transactions on Semicondudu).
ctorManufacturing, Vol.6, No.3, pp.258-267, 199
3). On the other hand, alkaline APM (ammonia / hydrogen peroxide / water) cleaning can remove particle contamination, but cannot remove metal contamination and corrodes tungsten and copper. However, there is a problem that it cannot be used for cleaning a substrate having the above. By using a specific surfactant under acidic conditions of pH 3 or less, the present inventors have excellent particle contamination removal properties despite of acidity, have excellent metal contamination removal properties, and also have the property of removing tungsten or copper during cleaning. It has been found that no corrosion occurs.

In order to adjust the pH of the solution to 3 or less, an acid such as hydrochloric acid, sulfuric acid, acetic acid, phosphoric acid, citric acid or oxalic acid may be added to the solution. These acids may be used alone or as a mixture of two or more. When an acid is added, the acid concentration in the cleaning solution is usually 0.01 to 10
%, Preferably 0.1 to 5% by weight. When a free acid type surfactant is used as the surfactant, the pH of the solution tends to be lowered without adding an acid.

In a solution containing a surfactant having a -SO ₃ -group (excluding sulfosuccinic acid diesters), the concentration of the surfactant is usually 0.1% based on the solution.
001 to 1% by weight, preferably 0.002 to 0.5% by weight. If the addition amount of the surfactant is too small, the removal performance of the particle contamination is not sufficient, and even if added more than this range, there is no change in the removal performance of the particle contamination,
Foaming is remarkable, and the possibility of biodegrading the waste liquid is increased.

Next, "(A2) methyltauric acid compound
Solution Containing Surfactant Consisting of Substance ".
The methyltauric acid-based compound is represented by the following formula (9).
Compounds. RCON (CH_Three) CH_TwoCH_TwoSO_ThreeX: Formula (9) (wherein, R is a hydrocarbon optionally substituted by a fluorine atom)
Radical, preferably substituted by a fluorine atom
Yes, C_nH_{2n + 1}, C_nH_2n-1, C_nH_2n-3Or C_nH _2n-5
A saturated or unsaturated hydrocarbon group, X is hydrogen, a cation
Indicates an atomic or cationic group. n is usually 8 to 2
0, preferably 13-17. Carbon number of hydrocarbon group
If n is too small, the ability to remove adhered particles is reduced.
Tend. )

As the methyltauric acid compound, for example,
If C₁₁H_{twenty three}CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and that
Salt, C₁₃H₂₇CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and
Its salt, C_FifteenH₃₁CON (CH_Three) CH_TwoCH_TwoSO_ThreeH and
And its salt, C₁₇H₃₅CON (CH_Three) CH_TwoCH_TwoSO_ThreeH
And its salts, C₁₇H₃₃CON (CH_Three) CH_TwoCH_TwoSO_Three
H and its salts, C₁₇H₃₁CON (CH_Three) CH_TwoCH_TwoS
O_ThreeH and its salts, C_{1 7}H₂₉CON (CH_Three) CH_TwoCH_Two
SO_ThreeH and salts thereof.

The solution containing a surfactant composed of a methyltauric acid compound is characterized in that there is no corrosion of electrodes and wirings, and there is little foaming in addition to particle contamination removal performance. If there is a lot of foaming, bubbles adhere to the substrate and cause an uneven surface reaction, or when draining the cleaning solution,
There are problems such as backflow in the piping. In a solution containing a surfactant having a methyltauric acid group, the concentration of the surfactant is usually 0.00
It is 1 to 1% by weight, preferably 0.002 to 0.5% by weight. If the amount of the methyltauric acid is too small, the particle contamination removing performance is not sufficient, and if the amount is more than this range, foaming becomes remarkable, which is not preferable.

The pH of the solution containing methyl tauric acid is as follows:
It is usually 0.1 to 13, preferably 0.5 to 11.5. Acids or alkalis may be added to the solution to adjust the pH. Acids include hydrochloric acid, sulfuric acid, acetic acid, phosphoric acid, citric acid, oxalic acid, and alkalis include ammonia, quaternary ammonium hydroxide (such as tetramethylammonium hydroxide), and amines (such as ethylenediamine and triethanolamine). Are used.

Next, - to Shoki for "(A3) -OSO ₃ comprises a surfactant comprising a surfactant and / or sulfosuccinic acid diester compound having a group, the solution pH is 4 or more." Examples of the surfactant having an —OSO ₃ — group include the following compounds (1) to (5).

Alkyl Sulfate Compound The alkyl sulfate compound is represented by the following formula (10)
The compound represented by these is mentioned. ROSO ₃ X Formula (10) (wherein, R represents an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, and X represents hydrogen, a cation atom or a cation atom group.) As an alkyl sulfate-based compound Include, for example, dodecyl sulfate and salts thereof.

Alkyl ether sulfate ester compound As the alkyl ether sulfate ester compound, a compound represented by the following formula (11) can be mentioned. RO (CH ₂ CH ₂ O) _n SO ₃ X Formula (11) (where R is an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, X is hydrogen, a cation atom or a cation atom group, n is the number of moles of ethylene oxide added, usually 1 to
Indicate an integer of 10, preferably 2 to 4. Examples of the alkyl ether sulfates include tetraoxyethylene lauryl ether sulfate and salts thereof.

Alkyl phenyl ether sulfate compound As the alkyl phenyl ether sulfate ester compound, there can be mentioned a compound represented by the following formula (12), a sulfated oil, a sulfated fatty acid ester compound, and a sulfated olefin compound. . _{R-ph-O (CH 2} CH 2 O) n -SO 3 X ··· formula (12) (wherein, R is an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, X is hydrogen, a cation atom Or a cation group, n is the number of moles of ethylene oxide added, and ph is a phenylene group.) Fluorinated surfactants in which the hydrogen of the alkyl group of the surfactants shown above is replaced by fluorine

Examples of the sulfosuccinic acid diester compound include a compound represented by the following formula (8).

Embedded image (In the formula, R represents an alkyl group optionally substituted with a fluorine atom, preferably an alkyl group having 4 to 20 carbon atoms optionally substituted with a fluorine atom, and X represents hydrogen, a cation atom or a cation atom group. Examples of the sulfosuccinic acid diester compound include, for example,
And di-2-ethylhexylsulfosuccinic acid and salts thereof.

The solution containing a surfactant having a -OSO ₃ -group and / or a surfactant comprising a sulfosuccinic acid diester compound has a pH of 4 or more, preferably a pH of 4 or more.
The pH is 4 to 12, particularly preferably 5 to 11.5. p
If the H is too low or too high, these surfactants are decomposed, and there is a problem that the cleaning ability decreases with time after the preparation of the cleaning solution. Acids or alkalis may be added to the solution to adjust the pH of the solution. Acids include hydrochloric acid, sulfuric acid, acetic acid, phosphoric acid, citric acid, oxalic acid, and alkalis include ammonia, quaternary ammonium hydroxide (such as tetramethylammonium hydroxide), and amines (such as ethylenediamine and triethanolamine). Are used.

A solution containing a surfactant having a -OSO ₃ -group and / or a surfactant comprising a sulfosuccinic acid diester does not cause corrosion of electrodes and wirings, has high particle contamination removal performance, and has relatively little foaming. It is characteristic. In a solution containing a surfactant having an —OSO ₃ — group and / or a surfactant composed of sulfosuccinic diesters, the concentration of the surfactant is usually 0.001 to 1% by weight, preferably 0.001% by weight, based on the solution. 0.00
2 to 0.5% by weight. If the addition amount of the surfactant is too small, the particle contamination removal performance is not sufficient, and even if added more than this range, the particle contamination removal performance does not change, foaming becomes remarkable, and the waste liquid is subjected to biodegradation treatment. It is not preferable because the impossibility of the case increases.

The surfactant used in (A1) to (A3) may be used in the form of a salt or an acid. Examples of the salt include alkali metal salts such as sodium and potassium, ammonium salts, primary, secondary, and tertiary amine salts. In the semiconductor manufacturing process, especially when cleaning around the gate electrode, considering that metal contamination adversely affects transistor performance, the surfactant used does not contain a metal salt, an acid form, or an ammonium salt, monoethanolamine. Salts and triethanolamine salts are preferred.

In selecting these cleaning liquids (A1) to (A3), comprehensive considerations are made on the basis of the required cleanliness level of the substrate surface, cost, foaming, biodegradability, chemical stability in the added cleaning agent, and the like. May be determined and an appropriate selection may be made. Among them, the cleaning liquid (A1) is preferably used from the viewpoint of simultaneously preventing corrosion of tungsten and copper, removing particles and removing metal contamination, and the cleaning liquid (A2) is preferably used from the viewpoint of removing particles and foaming.

Since the cleaning liquid of the present invention is used for cleaning a substrate for a semiconductor device, it is preferable that the cleaning liquid does not contain metal impurities or particles which, when adhered to the substrate, lower the electrical characteristics or the yield of the device. The content of metal impurities in the cleaning liquid is Fe, Al, Zn, and Cu, respectively.
Usually 1 ppm or less, preferably 0.02
It is desirably at most ppm.

Conventionally, it has been considered that particles cannot be removed without ultrasonic irradiation or brush scrub. However, according to the present invention, particles can be easily removed without performing ultrasonic irradiation or brush scrub. Preferably, the cleaning liquid used for cleaning mainly for removing particles is -SO _3-.
Surfactants having a group, more preferably alkyl sulfonic acids, alkyl benzene sulfonic acids, alkyl naphthalene sulfonic acids, methyl tauric acids, α-olefin sulfonic acids, naphthalene sulfonic acid condensates,
Fluorinated surfactants in which the hydrogen of the alkyl group of the surfactant is substituted with fluorine, particularly preferably surfactants of alkylbenzenesulfonic acid, alkyldiphenyletherdisulfonic acid, and methyltauric acid are used.

As the solvent for the cleaning liquids (A1) to (A3) of the present invention, water or a mixed solvent of an organic solvent and water, preferably water, is usually used. Further, the cleaning solution of the present invention includes
Hydrofluoric acid, ammonium fluoride, oxidizing agent, reducing agent,
A complexing agent, dissolved gas or the like may be added in a range that does not impair the effects of the present invention.

Since hydrofluoric acid and ammonium fluoride have an effect of etching a silicon oxide film and the like on the substrate surface, they are particularly effective in removing contamination such as photoresist residues firmly adhered to the substrate. . The concentration of hydrofluoric acid in the cleaning solution, usually 0.001 to
It is 0.5% by weight, preferably 0.01 to 0.1% by weight. The concentration of ammonium fluoride in the cleaning solution is usually 0.01 to 30% by weight based on the cleaning solution. If the amount is less than this range, a sufficient etching effect may not be obtained. If the amount is too large, etching of a substrate such as a silicon oxide film may be excessively performed, which may hinder device performance. As the oxidizing agent, for example, hydrogen peroxide, ozone, hypochlorous acid, as the reducing agent, hydrazine or the like, and as the dissolved gas, hydrogen, argon, nitrogen, or the like is used.

As the complexing agent, amines, amino acids, polyaminopolycarboxylic acids, phenol derivatives, polyaminophosphonic acids, 1,3-diketones and the like are used. Specific examples thereof include ethylenediamine, diethylenetriamine, 8-quinolinol, o-phenanthroline, glycine, iminodiacetic acid, ethylenediaminetetraacetic acid [EDT
A], trans-1,2-diaminocyclohexanetetraacetic acid [CyDTA], diethylenetriaminepentaacetic acid [DT
PA], triethylenetetramine hexaacetic acid [TTHA],
Catechol, tiron, ethylenediamine diorthohydroxyphenylacetic acid [EDDHA], ethylenediamine-N, N'-bis [(2-hydroxy-5-methylphenyl) acetic acid] [EDDHMA], N, N'-bis (2-
(Hydroxybenzyl) ethylenediamine-N, N'-diacetic acid [HBED], N, N'-bis (2-hydroxy-
5-methylbenzyl) ethylenediamine-N, N'-diacetate [HMBED], ethylenediaminetetrakis (methylenephosphonic acid) [EDTPO], nitrilotris (methylenephosphonic acid) [NTPO], propylenediaminetetra (methylenephosphonic acid) [PDTMP ], Acetylacetone and the like. In particular, (A) of the present invention
2) When (A3) is used, even if the pH is neutral to alkaline, the ability to remove particle contamination and the effect of preventing corrosion of tungsten and copper are excellent, but the ability to remove metal contamination is insufficient. In this case, it is preferable to add the above-mentioned complexing agent because it can compensate for the removal of metal contamination.

The cleaning liquid of the present invention is used for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on the surface. The transition metal compound in the present invention includes W (tungsten), Cu (copper), Ti (titanium), Cr (chromium), Co (cobalt), Zr (zirconium), H
f (hafnium), Mo (molybdenum), Ru (ruthenium), Au (gold), Pt (platinum), Ag (silver) and the like, and the transition metal compound is a transition metal nitride or oxide. , Silicide and the like. Examples of the transition metal or transition metal compound present on the surface of the semiconductor device substrate include W (tungsten), Cu (copper), and Ti.
(Titanium), Cr (Chrome), Co (Cobalt), Zr
Transition metals such as (zirconium), Hf (hafnium), Mo (molybdenum), Ru (ruthenium), Au (gold), Pt (platinum), and Ag (silver), and nitrides thereof.
Transition metal compounds such as oxides and silicides may be mentioned, preferably W (tungsten) and / or Cu
(Copper). In particular, it is suitable for cleaning a semiconductor device substrate having both tungsten and silicon on its surface. As a step of cleaning the substrate having copper on the surface,
When copper is used as a wiring material, it is used for cleaning copper wiring and the substrate surface. Specifically, a cleaning process after forming a copper film on a semiconductor device, in particular, CMP (Ch
washing process after performing emicalMechanical Polishing)
It is also used for cleaning after opening a hole in an interlayer insulating film on a copper wiring by dry etching.

The step of cleaning the substrate having tungsten on its surface is used for cleaning the gate electrode and the substrate surface when tungsten is used as the gate electrode material. Specifically, a cleaning step after forming a tungsten film on a semiconductor device, particularly a cleaning step after dry-etching a tungsten film, and a cleaning after ion implantation into an exposed silicon portion may be mentioned. By using the cleaning liquid of the present invention, particles and metals can be removed without performing ultrasonic irradiation and brush scrub. Therefore,
Cleaning of a gate electrode and a substrate surface when an ultra-fine (for example, a gate electrode having a width of about 0.15 μm) gate electrode is formed of tungsten, which is likely to be broken by ultrasonic cleaning or brush scrubbing. It is preferably used.

As a method for cleaning the substrate, a method is used in which the cleaning liquid is brought into direct contact with the substrate. More specifically, dip-type cleaning in which a cleaning tank is filled with a cleaning liquid to immerse the substrate, spray-type cleaning in which the cleaning liquid is sprayed onto the substrate for cleaning, spin cleaning in which the substrate is rotated at high speed while flowing the cleaning liquid from the nozzle onto the substrate, and the like Is mentioned. The washing method is appropriately selected depending on the purpose. The dip-type cleaning is capable of cleaning a large number of substrates at one time, but is characterized in that it takes time for one cleaning. Further, the spin cleaning has a feature that the number of substrates that can be cleaned at one time is small, but the time for one cleaning is short. The cleaning time is usually 30 seconds to 30 minutes, preferably 1 to 15 minutes in the case of dip cleaning, and 1 second to 15 minutes, preferably 5 seconds to 5 minutes in the case of spray cleaning or spin cleaning. . If the cleaning time is too short, the cleaning effect is not sufficient, and if the cleaning time is too long, only the throughput deteriorates, but the cleaning effect does not increase and is meaningless. The washing may be performed at room temperature, or may be usually performed by heating to about 40 to 80 ° C. in order to improve the washing effect.

In general, in a cleaning process for removing particle contamination, ultrasonic cleaning, cleaning by a physical force such as a brush scrub, and cleaning by a cleaning liquid are used in combination. Depending on the degree of contamination, cleaning using these cleaning liquids of the present invention may be used in combination with cleaning using these physical forces, but good cleaning results are obtained because of excellent particle removal performance without using them together. Can be

[0050]

EXAMPLES Next, specific embodiments of the present invention will be described with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist thereof. <Examples 1 to 32 and Comparative Examples 1 to 13> (Measurement of attached particles) A 4-inch silicon wafer with an oxide film was immersed in an aqueous solution in which alumina was dispersed. The immersed wafer was washed with ultrapure water for 10 minutes and dried by blowing nitrogen. (Alumina was selected as a typical example of particles that are extremely difficult to remove when adhered to the substrate.) Thereafter, fine particles adhered to the silicon wafer surface using a laser surface inspection device (LS-5000, manufactured by Hitachi Electronics Engineering Co., Ltd.) The number was measured, and it was confirmed that a fixed number (5000) or more of alumina particles of 0.21 μm or more were adhered, and a silicon wafer to which alumina was adhered was obtained.

The obtained silicon wafer to which alumina had adhered was washed by immersing it in a cleaning solution at room temperature for 10 minutes without using ultrasonic waves to remove alumina. The cleaning solution is an aqueous solution containing the surfactant and hydrofluoric acid shown in Table 1 at a predetermined concentration.
A cleaning solution composed of an aqueous solution to which an acid other than hydrofluoric acid was added so as to have the pH described in (1). After the cleaning, the silicon wafer was washed with ultrapure water for 10 minutes and dried by blowing nitrogen to obtain a cleaned silicon wafer. Particles remaining on the surface of the obtained cleaned silicon wafer were measured by a laser surface inspection device. The results are shown in Table 1. The number of adhered particles was shown by an average of three silicon wafers subjected to a cleaning treatment, the number of adhered particles measured, and the average value thereof.

(Confirmation of Tungsten and Copper Corrosion) In order to confirm the presence of corrosion of tungsten and copper, a 4-inch silicon wafer with a tungsten film and a 4-inch silicon wafer with a copper film were respectively placed in a cleaning solution at room temperature. ,
Dipped for 60 minutes. After immersion, each silicon wafer was washed with ultrapure water for 10 minutes, dried by blowing nitrogen, and observed for corrosion with an optical microscope and an electron microscope. The results are shown in Table 1. As the cleaning liquid, the same cleaning liquid as that used for (measurement of attached particles) was used. (Measurement of foaming property) The foaming property of the cleaning liquid was measured based on the Ross Miles method described in JIS. Specifically, the diameter is 50m
50 ml of the washing liquid was previously placed in the lower part of the glass tube of m, a certain amount (200 ml) of the washing liquid was dropped from the upper part of the glass tube over 30 seconds, and the height (mm) of the generated foam was read immediately after the drop. Was used to measure the foaming power. Since the foaming property indicates the amount of foaming in height (mm), the higher the height, the easier the foaming.

Comparative Example 14 (Measurement of Adhered Particles) As a cleaning liquid used for cleaning a silicon wafer to which alumina was adhered, 97% by weight of sulfuric acid and 31% by weight of hydrogen peroxide, which are a kind of SPM cleaning liquid, were used. Using a washing solution mixed at a ratio of 4: 1, the washing temperature was set to S
The cleaning was performed in the same manner as in Example 1 except that the temperature was set to 100 ° C., which is a normal temperature when cleaning was performed using a PM cleaning liquid. The results are shown in Table 1. (Confirmation of Corrosion of Tungsten and Copper) The same cleaning liquid as that used in the measurement of the adhered particles was used as the cleaning liquid, and the cleaning was performed in the same manner as in Example 1 except that the cleaning temperature was set to 100 ° C. The results are shown in Table 1.

<Comparative Example 15> (Measurement of adhering particles) As a cleaning liquid used for cleaning a silicon wafer to which alumina was adhered, 29% by weight ammonia water and 31% by weight hydrogen peroxide water, which are a kind of SC-1 cleaning liquid, were used. Except that the washing temperature was 45 ° C., which is a normal temperature when washing is performed using an SC-1 washing solution using a washing solution composed of an aqueous solution obtained by mixing water and water at a volume ratio of 1: 1: 5.
Performed in the same manner as in Example 1. The results are shown in Table 1. (Confirmation of Tungsten and Copper Corrosion) The same cleaning liquid as used in the measurement of the adhered particles was used as the cleaning liquid, and the cleaning temperature was set to 45 ° C., and the same procedure as in Example 1 was performed. Table-Results
It is shown in FIG.

<Comparative Example 16> (Measurement of adhered particles) The same as Comparative Example 13 except that ultrasonic irradiation was performed when cleaning the silicon wafer to which alumina was adhered (Himegasonic, 600W, 950 KHz, manufactured by Kaijo). I went to. The results are shown in Table 1.

<Comparative Examples 17 to 21> (Measurement of adhering particles) Hydrofluoric acid and / or an acid other than hydrofluoric acid shown in Table 1 was used as a cleaning liquid for cleaning a silicon wafer to which alumina had adhered. The procedure was performed in the same manner as in Example 1 except that a cleaning solution comprising an aqueous solution containing was used. The results are shown in Table 1. (Confirmation of Corrosion of Tungsten and Copper) The same procedure as in Example 1 was carried out except that the same cleaning liquid as used in the measurement of the adhered particles was used as the cleaning liquid. The results are shown in Table 1. In the table,
Hydrofluoric acid is abbreviated as “hydrofluoric acid”.

[0057]

[Table 1]

[0058]

[Table 2]

[0059]

[Table 3]

[0060]

[Table 4]

<Examples 33 to 36> (Measurement of Metal Contamination) 29% which is a kind of SC-1 cleaning solution containing a metal ion in a 4-inch bare silicon wafer.
Ammonia water, 31% hydrogen peroxide water and water in a volume ratio of 1:
It was immersed in a cleaning solution consisting of an aqueous solution mixed at a ratio of 1: 5. The immersed silicon wafer was washed with ultrapure water for 10 minutes and dried by blowing nitrogen to produce a silicon wafer contaminated with metal. The amount of Fe, Al, and Cu attached to the surface of the silicon wafer contaminated with the obtained metal was quantified, and the substrate surface concentration was calculated. Table 2 shows the results.

The silicon wafer contaminated with this metal is
The metal was removed by immersion in a cleaning solution for 10 minutes at room temperature. The cleaning solution is an aqueous solution containing a surfactant and hydrofluoric acid at a predetermined concentration shown in Table 2, and an aqueous solution to which an acid other than hydrofluoric acid is added so as to have a pH shown in Table 2. Was used. The washed silicon wafer was washed with ultrapure water for 10 minutes and dried by blowing nitrogen to obtain a cleaned silicon wafer. The amount of Fe, Al, and Cu remaining on the surface of the obtained cleaned silicon wafer was quantified, and the substrate surface concentration was calculated. In addition, the substrate surface concentration (atoms / cm ² ) was obtained by cleaning two silicon wafers, measuring the substrate surface concentration (atoms / cm ² ) of each substrate for each metal, and indicating the average value. . Table 2 shows the results.

In the present invention, the quantification of Fe, Al and Cu adhering to the silicon wafer surface was performed as follows. The silicon wafer was treated with a mixed solution of hydrofluoric acid 0.1% by weight and hydrogen peroxide 1% by weight,
e, Al and Cu were recovered. F contained in this solution
The amounts of e, Al and Cu were measured by a flameless atomic absorption method, and were converted to the substrate surface concentration (atoms / cm ² ).

[0064]

[Table 5]

[0065]

According to the cleaning method of the present invention, contamination of the metal member made of a transition metal such as tungsten or copper or a transition metal compound can be achieved without corroding and irradiating ultrasonic waves. No highly clean substrate surface can be achieved, which is very useful industrially.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C11D 3/04 C11D 3/04 17/08 17/08 (72) Inventor Yasuhiro Kawase Kurosaki Shiroishi, Yawata Nishi-ku, Kitakyushu-shi No. 1-1 Mitsubishi Chemical Corporation Kurosaki Office (72) Inventor Atsushi Ito 1-1 Kurosaki Castle Stone, Yawata Nishi-ku, Kitakyushu-shi Mitsubishi Chemical Corporation Kurosaki Office

Claims (25)

[Claims] 1. A cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface thereof, the cleaning solution comprising:
1) A cleaning solution for a semiconductor device substrate having a transition metal or a transition metal compound on a surface, comprising a solution selected from the group consisting of (A2) and (A3). (A1) -SO ₃ - surfactant having a group (excluding sulfosuccinic acid diester compound) comprises, pH
Comprise surfactants consisting of surfactants and / or sulfosuccinic acid diester compound having a group - solution (A3) -OSO ₃ comprising a surfactant but consisting of 3 or less solution (A2) methyl taurine acid compound , A solution having a pH of 4 or more 2. The method according to claim 1, wherein the cleaning solution is a solution (A1) and / or a solution (A
2. The cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on the surface according to claim 1, wherein the cleaning liquid comprises 2). 3. The cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to claim 2, wherein the cleaning solution comprises a solution (A1). 4. The cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to claim 1, wherein the pH of the solution (A1) is 2 or less. 5. The solution (A1) wherein the surfactant having a —SO ₃ — group is at least one member selected from the group consisting of a methyltauric acid compound, an alkylbenzenesulfonic acid compound and an alkyldiphenyletherdisulfonic acid compound. The cleaning liquid for a substrate for a semiconductor device, having a transition metal or a transition metal compound on a surface according to any one of claims 1 to 4. 6. A cleaning solution comprising the solution (A1), wherein -SO ₃ is contained in the cleaning solution.
6. The transition metal or transition metal on a surface according to claim 1, wherein the concentration of the surfactant having a group is 0.001 to 1% by weight based on the cleaning liquid for cleaning the substrate. A cleaning solution for a semiconductor device substrate having a compound. 7. The cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on its surface according to claim 2, wherein the cleaning solution comprises a solution (A2). 8. The cleaning solution comprising the solution (A2), wherein the concentration of the surfactant comprising a methyltauric acid-based compound is 0.001 to 1% by weight based on the cleaning solution. A cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on the surface according to any one of 2 and 7. 9. A semiconductor device having a transition metal or a transition metal compound on a surface according to claim 1, wherein the cleaning solution further contains hydrofluoric acid and / or ammonium fluoride. Cleaning solution for substrates. 10. A cleaning solution for a semiconductor device substrate having a transition metal or a transition metal compound on its surface according to claim 1, wherein the cleaning solution further contains an acid other than hydrofluoric acid. . 11. The transition metal or transition metal compound is copper or tungsten.
A cleaning solution for a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to any one of the above. 12. A cleaning solution for a substrate having silicon or silicon oxide on its surface, comprising a solution containing a surfactant comprising a methyltauric acid compound. 13. A method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface, wherein at least one solution selected from the group consisting of the following (A1), (A2) and (A3): A method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface thereof. (A1) A solution containing a surfactant having a -SO ₃ -group (excluding sulfosuccinic diesters) and having a pH of 3 or less. (A2) A solution containing a surfactant comprising a methyltauric acid-based compound ( A3) A solution containing a surfactant having a -OSO ₃ -group and / or a sulfosuccinic acid diester compound and having a pH of 4 or more. 14. The method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface thereof according to claim 13, wherein the cleaning liquid is (A1) and / or (A2). 15. The method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface thereof according to claim 14, wherein the cleaning liquid comprises a solution (A1). 16. The method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface thereof according to claim 13, wherein the solution (A1) has a pH of 2 or less. 17. The solution (A1) wherein the surfactant having a —SO ₃ — group is at least one member selected from the group consisting of a methyltauric acid compound, an alkylbenzenesulfonic acid compound and an alkyldiphenyletherdisulfonic acid compound. 13. The method according to claim 13, wherein:
7. A method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to any one of 6. 18. The cleaning solution (A1) wherein the concentration of the surfactant having a —SO ₃ — group is 0.
The method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to any one of claims 13 to 17, wherein the content is 001 to 1% by weight. 19. The method for cleaning a semiconductor device substrate having a transition metal or a transition metal compound on its surface according to claim 14, wherein the cleaning liquid is (A2). 20. The method according to claim 1, wherein the concentration of the surfactant comprising the methyltauric acid compound in the solution (A2) is 0.001 to 1% by weight based on the cleaning liquid when the substrate is cleaned. A method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to claim 13. 21. The cleaning liquid according to claim 13, wherein the cleaning liquid further contains hydrofluoric acid and / or ammonium fluoride.
21. The method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to any one of the above items. 22. The cleaning of a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to claim 13, wherein the cleaning liquid further contains an acid other than hydrofluoric acid. Method. 23. The transition metal or transition metal compound is copper or tungsten.
3. The method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface according to any one of 2. 24. The surface of a transition metal or a transition metal according to claim 13, wherein the cleaning of the semiconductor device having a transition metal or a transition metal compound on the surface is performed without irradiating an ultrasonic wave. A method for cleaning a substrate for a semiconductor device having a compound. 25. A method for cleaning a substrate having silicon or silicon oxide on its surface, comprising using a solution containing a surfactant comprising a methyltauric acid-based compound.