WO2001054180A1 - Method and detergent for cleansing semiconductor device substrate having transition metal or transition metal compound on surface - Google Patents

Abstract

A detergent for a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof, characterized by comprising a solution selected from the group consisting of the following (A1), (A2), and (A3); and a method of cleansing a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof, characterized by using the detergent. (A1) A solution which contains a surfactant having an -SO3- group (provided that the surfactant is not a sulfosuccinic diester compound) and has a pH of 3 or lower. (A2) A solution containing a surfactant comprising a methyltaurine compound. (A3) A solution which contains a surfactant having an -OSO3- group and/or a surfactant comprising a sulfosuccinic diester compound and has a pH of 4 or higher.

Description

 Description Cleaning method and cleaning agent for semiconductor device substrate having transition metal or transition metal compound on surface

 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.

Background art

 With the high performance and high integration of various devices represented by LSI and TFT flat panel displays, etc., the surface of the substrate used in the device is required to be further cleaned. Among the contamination on the substrate surface, in particular, metal contamination and particle contamination are required to remove metal and particles as much as possible in order to reduce the electrical characteristics and yield of the device. Generally, the substrate surface is cleaned with a cleaning liquid to remove metals and particles from the substrate surface.

 Conventionally, in order to clean the substrate surface, a cleaning process using a cleaning solution in which an acidic or alkaline solution and hydrogen peroxide are mixed (hereinafter referred to as “RCA cleaning”. (For example, RCA Review (1970.6), p. .207-233)).

In RCA cleaning, cleaning is performed by selecting a cleaning solution that matches the contaminants on the substrate surface. For example, if the substrate surface is contaminated by particles or organic matter, “SC-1” or “ Cleaning is performed using a cleaning solution called ammonia, hydrogen peroxide and water, which is called “APM”. The contamination by metal on the substrate surface is cleaned with a cleaning solution called “SC-2” or “HPM” consisting of hydrochloric acid, hydrogen peroxide and water. For contamination of photoresist and resist residue on the substrate surface, cleaning with a cleaning solution called “SPM” consisting of sulfuric acid and hydrogen peroxide is performed. On the other hand, in order to improve the performance of semiconductor devices such as transistors, reduction of the resistance of gate electrodes and wiring materials constituting the semiconductor devices is being studied.

 Conventionally, polysilicon, WSi (tungsten silicide), CoSi (cobalt silicide), TiSi (titanium silicide), etc. have been mainly used as gate electrode materials. Use of a metal material for the gate material is being studied to increase resistance. As such metal materials, W (tungsten) and Cu (copper) have been attracting attention.

 When the gate electrode material is polysilicon, WSi, CoSi, TiSi, etc., the cleaning solution containing hydrogen peroxide was used for cleaning after forming the gate electrode on the substrate. Cleaning (RCA cleaning) is applicable. However, when the gate electrode material was a metal such as stainless steel, it was found that the RCA cleaning would corrode the electrode material. As a result of the analysis, it was found that this was due to the fact that hydrogen peroxide in the cleaning solution used for the RCA cleaning dissolves the ionized tungsten.

 In this way, to achieve higher performance of semiconductor devices, metal electrodes such as tungsten are newly introduced as gate electrode materials for semiconductor devices, and copper and tungsten are newly introduced as wiring materials for semiconductor devices. It has begun.

 However, at present, no cleaning liquid that satisfies the following three requirements has been found as a cleaning liquid for a substrate having these electrodes and wiring formed on the surface.

 ① Do not corrode electrodes and wiring of tungsten, copper, etc.

 ② Excellent in removing particle contamination on the substrate surface.

 (3) Excellent in removing metal contamination on the substrate surface.

 The present invention has been made in order to solve the above-mentioned problem, and is intended for cleaning a substrate having a transition metal or a transition metal compound such as tungsten or copper partially or entirely on its surface.

 ① Do not corrode such metal,

②Excellent removal of particle contamination on the substrate surface To provide a cleaning solution and a cleaning method satisfying the two requirements, more preferably,

 ③Excellent removal of metal contamination on substrate surface,

The purpose is to provide a cleaning solution and a cleaning method that simultaneously satisfy the three requirements.

 In addition, in order to achieve higher performance (higher density) of semiconductor devices, technologies that reduce the size of semiconductor device patterns and increase the aspect ratio (ratio of pattern height to pattern width) are used. ing. 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. Disclosure of the invention

 The present inventors have conducted intensive studies to solve the above problems, and as a result, have found that the above problems can be satisfied by using a specific solution containing a specific surfactant as a cleaning solution. Reached.

 That is, the gist of the present invention is a cleaning liquid for a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface, the cleaning liquid being selected from the group consisting of the following (A 1), (A 2) and (A 3) Cleaning liquid for a semiconductor device substrate having a transition metal or a transition metal compound on the surface characterized by comprising a solution to be washed, and a semiconductor device having a transition metal or a transition metal compound on the surface characterized by using the cleaning liquid The present invention resides in a method of cleaning a chair substrate.

_{(A 1) - S 0 3} - surfactant having a group (excluding sulfosuccinate diester Le compounds) comprises, p H is 3 or less solution,

 (A 2) a solution containing a surfactant comprising a methyl diphosphate compound,

A solution containing a surfactant having a (A 3) -OS◦ ₃ — group and / or a surfactant comprising a sulfosuccinic acid diester-based compound and having a pH of 4 or more. BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

 The cleaning solution of the present invention comprises at least one solution selected from the group consisting of the following (Al), (A2) and (A3).

_{(A 1) - S 0 3} - surfactant having a group (excluding sulfosuccinate diester Le compounds) comprises, pH is 3 or less solution,

 (A 2) a solution containing a surfactant comprising a methyl phosphate compound,

(A3) -OS 0 ₃ - comprises a surfactant comprising a surfactant and / or sulfosuccinic acid di ester compound having a group, solution p H is 4 or more. First, _{"(A 1) - S 0 3} - surfactant having a group (excluding sulfosuccinic acid diester compound), with the solution pH is 3 or less" to more describes details.

- S 0 ₃ - Examples of the surfactant having a group, compounds of ①~⑨ shown below are exemplified.

 ①Alkyl sulfonic acid compound

 Examples of the alkylsulfonic acid compound include a compound represented by the following formula (1).

S 0 ₃ X · · · Formula (1)

 (In the formula, 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.)

The alkyl sulfonic acids, e.g., C ₈ H ₁₇ S0 ₃ H and its salts, C ₉ H丄₉ S◦ ₃ H and its salts, C i oH ₂丄S 0 ₃ H and its salts, C HzgSOgH and its salts _{, C i 2 H 25 S 0} 3 H and salts thereof, C ₁₃ H ₂₇ S0 ₃ H and salts thereof, C ₁₄ H ₂₉ S0 ₃ H and salts thereof, C ₁₅ H ₃₁ S0 ₃ H and its salts, C ₁₆ H ₃₃ S 0 ₃ H and its salts, C丄₇ H ₃₅ S 0 ₃ H and its salts, salts of _{C 1 8 H 37 S 0 3} H and its like.

 ②Alkylbenzene sulfonic acid compound

Alkylbenzenesulfonic acid-based compounds include compounds represented by the following formula (2). Things.

R-ph-S0 ₃ X

 (In the formula, R represents an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, X represents hydrogen, a cation atom or a cation atom group, and ph represents a phenylene group.)

 Examples of the alkylbenzenesulfonic acids include dodecylbenzenesulfonic acid and salts thereof.

 (3) Alkyl naphthene sulfonic acid compound

 Examples of the alkyl group constituting the alkylnaphthylene sulfonic acid include a compound represented by the following formula (3).

 · · Expression (3)

(Wherein, II ¹ and R ^{2 each} represent an alkyl group, preferably an alkyl group having 1 to 10 carbon atoms, X represents hydrogen, a cation atom or a cation atom group, and m and n each represent 0 to 4 Where l≤m + n≤7, preferably l≤m + n≤4.)

 Examples of the alkylnaphthylene sulfonic acids include dimethylnaphthalenesulfonic acid and salts thereof.

 ④Methyl phosphoric acid compound

 Examples of the methyltauric acid-based compound include a compound represented by the following formula (4) .o

RCON (CH ₃ ) CH ₂ CH ₂ S0 ₃ XEquation (4)

(Wherein, R represents a hydrocarbon group, preferably, C _n H _{2 n +} have C _n H _{2 n} - have C _n H _{2 n} _ ₃ or C _n H _2n - ₅ saturated or unsaturated hydrocarbon group of, X represents hydrogen, a cation atom or a cation atom group, and n represents an integer of usually 8 to 20, preferably 13 to 17. If n, which is the number of carbon atoms of the hydrocarbon group, is too small, attached particles are removed. Ability tends to decrease. )

The methyl evening Urin acid compounds, for example, C i丄 _{H 23 C ON (CH 3)} CH 2 CH 2 S_〇 ₃ H and salts _{thereof, C! A H 2 7 C} ON (CH 3) CH 2 CH 2 S0 ₃ H and salts _{thereof, C 15 H 31 CON (CH} 3) CH 2 CH 2 S◦ 3 H and salts _{thereof, C! 7 H 35 C ON} (CH 3) CH 2 CH 2 S 0 3 H and its salts , C丄 _{7 H 33 C ON (CH 3} ) CH 2 CH 2 S0 3 H and salts _{thereof, C 17 H 31 CON (CH} 3) CH 2 CH 2 S0 3 H and salts thereof, C ₁₇ H ₂₉ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ H and its salts.

 ⑤Alkyl diphenyl terdisulfonic acid compound

 Examples of the alkyl diphenyl ether disulfonic acid compound include a compound represented by the following formula (5).

R-ph (S0 ₃ X) -0-ph-S0 ₃ XEquation (5)

(In the formula, R represents an alkyl group, preferably an alkyl group having 8 to 20 carbon atoms, X represents hydrogen, a cation atom or a cation atom group, and ph represents a phenylene group.)

 Examples of the alkyl diphenyl ether disulfonic acids include nonyl diphenyl diterdisulfonic acid and salts thereof, dodecyl diphenyl diterdisulfonic acid and salts thereof, and the like.

 ⑥Hiichisai Lefinsulfonic acid compound

 Examples of the hypoolefin sulfonic acid-based compound include 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 S 0 ₃ XEquation (6)

RCH ₂ CH (OH) (CH ₂ ) _n S0 ₃ X

(In the formula, R represents 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 an integer.

Indicates an integer from 1 to 10. )

 ⑦Naphthalenesulfonic acid condensate

Examples of the naphthylene sulfonic acid condensate include? -Naphthylene sulfonic 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-mentioned ① to ⑦ is replaced with fluorine.

 Of these surfactants, a methyltauric acid-based compound, an alkylbenzene sulfonic acid-based compound, and an alkyl diphenyl ether disulfonic acid-based compound are preferably used because of their excellent property of removing particle contamination.

 In addition, when the pH of the washing solution is neutral, the pH is 3 or less, so that the removal of particle contamination is excellent.Alkylbenzenesulfonic acid-based compounds and alkyldiphenyletherdisulfonic acid-based compounds Is particularly preferably used.

 Further, even when 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 foaming. .

Incidentally, diesters of sulfosuccinic acid compounds are represented by the following formula _{(8), - S 0 3} - is a surfactant having a group, the acidic solution, removed for cleaning ability decreases with time ing. This is presumed to be because sulfosuccinic acid diesters have one —S 0 3 group but have an ester structure, which causes decomposition in acidic solutions.

ROCOCH ₂

 I

ROCOCHSO3X

 .. 'Expression (8)

 (In the formula, R is 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, X is hydrogen, a cation atom or a cation. Indicates an atomic group.)

- S 0 ₃ - surfactant having a group (excluding sulfosuccinic acid diester of compound) solution containing the, p H is 3 or less, preferably p H 2 or less, further preferred properly the p H l. 5 or less, particularly preferably pH is 1.0 or less. If the pH is too high, the ability to remove metal contamination will decrease. In the case of alkyl benzene sulfonic acids and alkyl diphenyl ether disulfonic acids, particle removal performance is also high. It is not preferable because it lowers.

 It is known that the removal of particle contamination generally decreases when the pH is reduced by adding an acid to the cleaning solution (Itano et al., IEEE Transactions on Semiconductor Manufacturing, Vol. 6, No. 3, pp. 258). -267, 1993). On the other hand, APM (ammonia / hydrogen peroxide / water) cleaning can remove particle contamination, but cannot remove metal contamination and corrodes tungsten and copper. In addition, there is a problem that it cannot be used for cleaning substrates having these metals. The present inventors have found that by using a specific surfactant under acidic conditions of pH 3 or less, the present invention provides excellent particle contaminant removal properties regardless of acidity, excellent metal contaminant removal properties, and furthermore, during cleaning. It has been found that corrosion of tungsten and copper does not occur. 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 concentration of the acid in the washing solution is usually from 0.01 to 10% by weight, preferably from 0.1 to 5% by weight. When a free acid type surfactant is used as the surfactant, the pH of the solution tends to decrease even without adding an acid.

- S 0 ₃ -. Surfactants having a group (excluding sulfosuccinic acid diesters) in a solution containing a concentration of surfactant, relative to the solution, usually 0 0 0 1-1 wt%, preferably Is from 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 the surfactant is added beyond this range, there is no change in the removal performance of the particle contamination, the foaming becomes remarkable, and the waste liquid is generated. It is not preferable because the impossibility of decomposition processing increases. Next, “(A 2) a solution containing a surfactant comprising a methyltauric acid-based compound” will be described in detail.

Examples of the methyltauric acid-based compound include a compound represented by the following formula (9). RCON (CH ₃ ) CH ₂ CH ₂ S 0 ₃ X

(Wherein, R optionally substituted hydrocarbon group with a fluorine atom, preferably may be substituted with full Tsu _{atom, C N H 2 n + i} , C N H 2 N - have C _n H _{2 n} _ ₃ or C _n H _{2 n} -. ₅ saturated or unsaturated hydrocarbon group of, X is a hydrogen, a cation atom or a cation atomic group n is typically 8-2 0, preferably 1 3 If the carbon number n of the hydrocarbon group is too small, the ability to remove adhered particles tends to decrease.)

The methyl taurine acid compounds, for _{example, CHHZ JJ C ON (CH 3} ) CH 2 CH 2 S 03 H and salts _{thereof, C 1 3 H 2 7 C} ON (CH 3) CH 2 CH 2 S 0 3 H and a salt _{thereof, C 1 5 H 3 1 CON} (CH 3) CH 2 CH 2 S 0 3 H and salts _{thereof, C 1 Y H 3 5 CON} (CH 3) CH 2 CH 2 S 0 3 H and its salts, C _{1 7} H _{3 3} CON (CH ₃ ) CH ₂ CH ₂ S〇 ₃ H and its salt, C ₁₇ H _{3 1} C ON (CH ₃ ) CH ₂ CH ₂ S 0 ₃ H and its salt, C ₁₇ H such as _{2 9 CON (CH 3) CH} 2 CH 2 S 0 3 H及beauty salts thereof.

 A solution containing a surfactant consisting of a methyltauric acid-based compound is characterized in that there is no corrosion of electrodes and wiring, particle contamination removal performance, and little bubbling. If there is a lot of bubbles, there will be problems such as bubbles adhering to the substrate, causing an uneven surface reaction, and backflow in the piping when draining the cleaning solution.)

 In a solution containing a surfactant having a methyl phosphate group, the concentration of the surfactant is usually 0.001 to 1% by weight, preferably 0.002 to 0.5% by weight, based on the solution. . If the amount of the methyltauric acid is too small, the particulate contamination removal 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 methyltauric acids is usually 0.1 to 13, preferably 0.5 to 11.5. An acid or alkali 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 such as ammonia and quaternary ammonium hydroxide (tetramethylammonium). Monoxide, etc.) and amines (ethylenediamine, triethanolamine, etc.). Next, "(A3) - OS0 ₃ - comprises a surfactant comprising a surfactant and / or Suruhoko Haq acid diester compound having a group, p H is dissolved solution at 4 or more" to Shoki about.

-OS 0 ₃ - Examples of the surfactant having a group, compounds of ①~④ shown below can be mentioned up.

 ①Alkylsulfate compounds

 Examples of the alkyl sulfate compound include a compound represented by the following formula (10).

ROS〇 ₃ X '· · Equation (10)

 (In the formula, 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.)

 Examples of the alkyl sulfate-based compound include dodecyl sulfate and salts thereof.

 ②Alkyl ether sulfate compound

 Examples of the alkyl ether sulfate compound include a compound represented by the following formula (11).

_{RO (CH 2 CH 2 0)} n S0 3 X · · · (1 1)

 (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 atom group, n is the number of moles of ethylene oxide added, usually 1 to 10, preferably 2 Shows an integer of ~ 4.)

 Examples of the alkyl ether sulfates include tetraoxyethylene propyl ether sulfate and salts thereof.

 ③ Alkyl phenyl ether sulfate compound

Examples of the alkyl phenyl ether sulfate compound include a compound represented by the following formula (12), a sulfated oil, a sulfated fatty acid ester compound, and a sulfated oil. Compounds.

R-ph-O- (CH ₂ CH ₂ 0) _n -S0 ₃ X

(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 atom group, n is the number of moles of ethylene oxide added, usually 1 to 10, preferably 2 Represents an integer of up to 4. ph represents a phenylene group.)

(4) A fluorine-based surfactant in which the hydrogen of the alkyl group of the surfactant shown in (1) to (3) above has been replaced with fluorine.

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

ROCOCH ₂

 I

ROCOCHSO3X

 • · 'Expression (8)

 (In the formula, R is 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, X is hydrogen, a cation atom or a cation. Indicates an atomic group.)

 Examples of the sulfosuccinic acid diester compound include di-2-ethylhexylsulfosuccinic acid and salts thereof.

-OS 0 ₃ - solution containing a surface active agent comprising a surfactant and / or sulfosuccinic acid diester Le compounds having a group, pH of 4 or more, preferably pH 4 to 12, particularly preferably pH 5~ll. 5 If the pH 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 triethylamine). And the like are used. -OS 0 ₃ - no corrosion of the solution electrodes, wiring including a surfactant consisting of surfactants and or sulfosuccinate diester Le compounds having a group, high party Kuru decontamination performance, relatively foaming is small that Is the feature.

-OS 0 ₃ - in a solution containing a surface active agent comprising a surfactant and / or sulfosuccinic acid diester Le compounds having a group, the concentration of the surfactant is to pair the solution, usually from 0.001 to 1 wt% And preferably 0.002 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 the surfactant is added in an amount larger than this range, there is no change in the particle contamination removal performance, foaming becomes remarkable, and the waste liquid is biodegraded. It is not preferable because the impossibility of doing so increases. The surfactants used in (A1) to (A3) may be used in the form of a salt or in the form of 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 metal salts, acid form, ammonium salt, Preference is given to ethanolamine salts, triethanolamine salts and the like.

 In selecting these cleaning liquids (A1) to (A3), comprehensive selection is required based on the required cleanliness level of the substrate surface, cost, foaming, biodegradability, and chemical stability in the added cleaning agent. It is only necessary to make the appropriate selection. 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 solution is Fe, Al, Zn, and Cu, respectively. It is desirable that the concentration be 0.02 ppm or less.

In the past, it was thought that particles could not be removed without ultrasonic irradiation or brush scrubbing. However, according to the present invention, particles can be easily removed without performing ultrasonic irradiation or brush scrub. The cleaning liquid used for cleaning mainly for the purpose of removing particles is preferably a surfactant having a —so ₃ — group, more preferably an alkylsulfonic acid, an alkylbenzenesulfonic acid, an alkylnaphthylenesulfonic acid, Methyl diphosphoric acid, phosphoric acid sulfonic acid, naphthylene sulfonic acid condensate, fluorine-based surfactant in which hydrogen of the alkyl group of the above surfactant is substituted with fluorine, particularly preferably alkylbenzene sulfonic acid, alkyldiphene Surfactants such as toluene terdisulfonic acid and methyl phosphoric acid are used.

 As the solvent for the washing 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, to the cleaning solution of the present invention, hydrofluoric acid, ammonium fluoride, an oxidizing agent, a reducing agent, a complexing agent, a dissolved gas, or the like may be added as long as the effects of the present invention are not impaired.

 Hydrofluoric acid and ammonium fluoride have an effect of etching a silicon oxide film or the like on the substrate surface, and are particularly effective in removing contamination such as photoresist residue firmly adhered to the substrate. The concentration of hydrofluoric acid in the cleaning solution is usually 0.01 to 0.5% by weight, preferably 0.01 to 0.1% by weight, based on the cleaning solution. Further, 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.

Examples of the oxidizing agent include hydrogen peroxide, ozone, and hypochlorous acid. Examples of the reducing agent include hydrazine, and examples of the dissolved gas include hydrogen, argon, and nitrogen. As the complexing agent, amines, amino acids, polyaminopolycarboxylic acids, phenol derivatives, polyaminophosphonic acids, 1,3-diketones and the like are used. That Specific examples include ethylenediamine, diethylenetriamine, 8-quinolinol, o-phenanthroline, glycine, iminodiacetic acid, ethylenediaminetetraacetic acid [EDTA;], trans-1,2-diaminocyclohexane4. Acetic acid [CyDTA], Diethylenetriamine pentaacetic acid [DTPA], Triethylenetetramine 6acetic acid [T THA:], Catechol, Tylon, Ethylenediaminediorthohydroxyphenylacetic acid [EDDHA], Ethylenediamine N, N, Bis [( [2-Hydroxoxy-5-methylphenyl) acetic acid] [EDDHMA], N, N, monobis (2-hydroxybenzyl) ethylenediamine monoN, N, monoacetic acid [HBED], N, N, monobis (2-Hydroxy-5-methylbenzyl) Ethylenediamine N, N, monoacetic acid [HMBED], Ethylenediaminetetrakis (methylenephosphonic acid) [EDT PO], tritolytris (methylene phosphonic acid) [NTPO], propylene diamine tetra (methylene phosphonic acid) [PDTMP:], acetyl acetate, and the like.

 In particular, when (A2) and (A3) of the present invention are used, even if the pH is neutral to alkaline, the particle contamination removal performance and the effect of preventing corrosion of tungsten and copper are excellent, but the metal contamination removal performance is excellent. Will be 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 semiconductor device substrate having a transition metal or a transition metal compound on the surface. The transition metals in the present invention include W (silver), Cu (copper), Ti (titanium), Cr (chromium), Co (cobalt), Zr (siliconium), Hf (hafnium), Transition metals such as Mo (molybdenum), Ru (ruthenium), Au (gold), Pt (platinum), and Ag (silver). Transition metal compounds are transition metal nitrides, oxides, and silicides. And the like. The transition metals and transition metal compounds present on the surface of the substrate for semiconductor devices include W (tungsten), Cu (copper), Ti (titanium), Cr (chromium), Co (connorth), and Z Transition metals such as r (zirconium), Hf (hafnium), Mo (molybdenum), Ru (ruthenium), Au (gold), Pt (platinum), Ag (silver), and their nitrides and oxides And a transition metal compound such as a silicide. Stainless steel) and / or Cu (copper). In particular, it is suitable for cleaning semiconductor device substrates having both tungsten and silicon on the surface.

 The step of cleaning a substrate having copper on the surface is used for cleaning copper wiring and the substrate surface when copper is used as a wiring material. Specifically, a cleaning process after forming a copper film on a semiconductor device, particularly a cleaning process after performing CMP (Chemical Mechanical Polishing) on a copper film, and a dry etching process on an interlayer insulating film on copper wiring. It is also applied for cleaning after opening a hole.

 The step of cleaning the substrate having tungsten on the 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, in particular, a cleaning step after dry etching of a tungsten film, and a cleaning after ion implantation into an exposed silicon portion.

 By using the cleaning liquid of the present invention, particles and metals can be removed without performing ultrasonic irradiation or brush scrub. Therefore, there is a high possibility that the gate electrode will be broken by ultrasonic cleaning or brush scrubbing. If the gate electrode is made of ultra-fine tungsten (for example, the gate electrode has a width of about 0.15 m), the gate electrode And for cleaning the substrate surface.

 As a method for cleaning the substrate, a method is used in which the cleaning liquid is brought into direct contact with the substrate. Specifically, dip-type cleaning in which the cleaning tank is filled with the cleaning liquid to immerse the substrate, spray-type cleaning in which the cleaning liquid is sprayed onto the substrate, and cleaning, and high-speed rotation of the substrate while flowing the cleaning liquid from the nozzle onto the substrate Spin-cleaning, etc., that rotates. The washing method is appropriately selected depending on the purpose. Dip-type cleaning is capable of cleaning many substrates at once, but is characterized in that one cleaning takes a long time. Spin-type cleaning is characterized in 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 for dip cleaning, preferably 1 to 15 minutes, and usually 1 second to 15 minutes for spray cleaning and spin cleaning. Preferably it is 5 seconds to 5 minutes. If the cleaning time is too short, the cleaning effect If the result is not enough, if it is too long, the throughput will only worsen, and the cleaning effect will not increase and there is no point. The washing may be carried out at room temperature, or may be carried out usually at a temperature of about 40 to 80 ° C. in order to improve the washing effect.

 Generally, in the cleaning process for the purpose of removing particle contamination, cleaning by ultrasonic irradiation, cleaning by a physical force such as brush scrub, and cleaning by a cleaning liquid are used in combination. Depending on the degree of contamination, the cleaning using the cleaning solution of the present invention may be used in combination with the cleaning using these physical forces. However, even without using the cleaning liquid, excellent cleaning results can be obtained because of excellent particle removal performance. can get. Example

 Next, specific embodiments of the present invention will be described with reference to examples. However, 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 they adhere to the substrate.)

 After that, the number of fine particles adhering to the silicon wafer surface was measured using a laser surface inspection device (LS-500, manufactured by Hitachi Electronics Engineering Co., Ltd.). It was confirmed that these 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 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, and an acid other than hydrofluoric acid is added so that the pH shown in Table 1 is obtained. A washing solution composed of the aqueous solution was used.

After the cleaning, the silicon wafer is rinsed with ultrapure water for 10 minutes and dried by blowing nitrogen. After drying, a washed silicon wafer was obtained. Particles remaining on the surface of the obtained cleaned silicon wafer were measured by a laser surface inspection device. Show results—

Shown in 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.

 (Confirmation of corrosion of tungsten and copper)

 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 immersed in a cleaning solution for 60 minutes at room temperature. After immersion, each silicon wafer was washed with ultrapure water for 10 minutes, dried by nitrogen blowing, and observed for corrosion with an optical microscope and an electron microscope. The results are shown in Table 1.

 As the washing liquid, the same washing liquid as used in (Measurement of attached particles) was used. (Measurement of foamability)

 The foaming property of the cleaning liquid was measured based on the Ross Miles method described in JIS. Specifically, 50 ml of the washing liquid is previously placed in the lower part of a 50 mm diameter glass tube, and a certain amount (200 ml) of the washing liquid is dropped from the upper part of the glass tube over 30 seconds. The height (mm) of the generated foam was read immediately after the drop and the foaming power was measured. The foaming property indicates the amount of foaming by height (mm), so the higher the height, the easier the foaming.

<Comparative Example 14>

 (Measurement of attached particles)

 As a cleaning solution used for cleaning silicon wafers with alumina attached, a cleaning solution that is a type of SPM cleaning solution, which is a mixture of 97% by weight sulfuric acid and 31% by weight hydrogen peroxide in a 4: 1 volume ratio is used. Example 1 was repeated except that the temperature was set to 100 ° C., which is a normal temperature when cleaning was performed using an SPM cleaning solution. The results are shown in Table 1.

 (Confirmation of corrosion of tungsten and copper)

Use the same cleaning liquid as used for the measurement of the adhered particles as the cleaning liquid, and adjust the cleaning temperature. The procedure was performed in the same manner as in Example 1 except that the temperature was changed to 100 ° C. Table 1 shows the results.

<Comparative Example 15>

 (Measurement of attached particles)

 As a cleaning solution used to clean silicon wafers with alumina attached, 29-1 wt% ammonia water, 31 wt% hydrogen peroxide solution and water, which are a type of SC-1 cleaning solution, are mixed at a volume ratio of 1: 1: 5. The cleaning was performed in the same manner as in Example 1 except that the cleaning temperature was 45 ° C., which is the normal temperature when the cleaning was performed using the SC-1 cleaning liquid, using the cleaning solution composed of the aqueous solution. 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 same procedure as in Example 1 was performed except that the cleaning temperature was 45 ° C. The results are shown in Table 1.

<Comparative Example 16>

 (Measurement of attached particles)

 Ultrasonic irradiation was performed when cleaning the silicon wafer to which alumina was adhered (Himega Sonic, 600 W, 950 KHz, manufactured by IJI Co., Ltd.). The results are shown in Table 1.

<Comparative Examples 17 to 21>

 (Measurement of attached particles)

 The same as in Example 1 except that the cleaning liquid used for cleaning the silicon wafer to which alumina was adhered was an aqueous solution containing hydrofluoric acid and / or an acid other than hydrofluoric acid as shown in Table-1. I went to. The results are shown in Table 1.

 (Confirmation of corrosion of tungsten and copper)

 The cleaning was performed in the same manner as in Example 1 except that the same cleaning liquid as used in the measurement of the adhered particles was used. The results are shown in Table 1.

In the table, hydrofluoric acid is abbreviated as “hydrofluoric acid”. Table 1 (Part 1)

 * 1: In the table, -ph- represents a phenylene group.

* 2: pH adjustment with ammonia water

Table 1 (Part 2)

※! ): R is a mixture of one C ₁₅ H ₃₁ (about 28%), one C ₁₇ H ₃₅ (about 21%), and —C ₁₇ H ₃₃ (about 44%), and R—CON (CH ₃ ) C ₂ H ₄ S0 _{3 c} 1 indicating the Na: is a mixture of R gar CH ^ and one _{C 13 H 27, R-CON} (CH 3) shows the C ₂ H ₄ SQ ₃ Na.

Table 1 (Part 3)

 Hydrofluoric acid Hydrofluoric acid aqueous solution Cleaning liquid Number of adhered particles

 Surfactant Corrosion Prevention Remarks

; PH types other than Tatsuno, 0.2 m or more

 Acid (individual wafer) W Cu

Washing; After washing Yoon B, Example _{27 C 12 H 25 OS0 3 M} (* 3) 0. 5 6. 4 A3 712 No No

Example 28 C ₁₂ H ₂₅ OS0 ₃ Na 0.5 5.8 A3 813 None None

Example _{29 C, 2 H 25 0 (} C 2 H 4 0) 4 S0 3 M 0. 5 - 6. 2 A3 945 No No

tL Pingyai Wl C ₁₂ H ₂₅ OS0 ₃ Na 0.5 Ship> 5000 2082 None None

Example 30 C ₁₂ H ₂₅ OS0 ₃ M 6.3 A3 1199 None None 83 Example 31 C ₂ H ₂₅ 0 (C ₂ H ₄₀ ) ₄ S0 ₃ M 6.3 A3 2750 None None

Comparative Example _{8 C 12 H 25 OS0 3 M} 0. 02 hydrochloride 0.5 4630 No No

Comparative Example _{9 C, 2 H 25 0 (} C 2 H 4 0) 4 S0 3 M 0. 02 hydrochloride 0.5> 5000 No No

 G2 Lehexyl Sulfo

Example 32

 0.5 5.5 A3 444 None None

 Succinic acid Na salt

 ό 6

* 3 Μ indicates NH (CH ₂ CH ₂ OH) ₃ .

O MM CC

Table 1 (Part 4)

 Hydrofluoric acid Hydrofluoric acid aqueous solution Number of adhered particles

 Surfactant Corrosion foaming Remarks

? PH other than Tatsuno 0 or more

 Kind: cinnamate / sulfuric acid (single wafer) W Cu

 (wt%) (wt%) '¾fl (mm) Comparative Example 10 / "No ^" ^ No 丄 "?"

 0.5 1 1 3 1> 5000 1 1

 Ether acetic acid (* 4)

 Lauryl trimethyl ammonium

Comparative Example 1 1 υ. D ― 1 3.2 ＞ 5000

 Chloride (* 5)

 Polyoxyethylene polyoxy

 0.5> 5000

 Noro Hirenokuri << J-Le (* 6)

 + / ヽ ヽ

Comparative Example 13 U-|: l \ l

 (* 7)

Comparative Example 14 <0> 5000> 5000 Yes Yes (* 8) Hihaya Father 5> 5000 Yes Yes #y ReComparative Example 16 About "854 (* 10) Comparative Example 17 Hydrochloric acid 0.5> 5000 No No

Comparative Example 18 Oxalic acid 1.0〉 5000 None None

Comparative Example 19 Cunic acid 1.8 3777 None None

Comparative Example 20 0.05 2 1〉 5000 None None

Comparative Example 21 0.05 0.05 Hydrochloric acid 0.8> 5000 None None

 * 4 Carboxylic acid type anionic surfactant

 Thu 5 Cationic surfactant

 * 6 Nonionic surfactant

 * 7 Amphoteric surfactant

 * 8 SPM cleaning solution

 * 9 SC-1 cleaning solution

 * 10 SC-1 cleaning solution, with ultrasonic irradiation.

^

Example 3 3 to 3 6>

 (Measurement of metal contamination)

 A 4-inch bare silicon wafer is composed of an aqueous solution containing a mixture of 29% ammonia water, 31% hydrogen peroxide water, and water at a volume ratio of 1: 1: 5, a type of SC-1 cleaning solution containing metal ions. It was immersed in the cleaning solution. 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 amounts of Fe, Al, and Cu attached to the silicon wafer surface contaminated with the obtained metal were quantified, and the substrate surface concentration was calculated. The results are shown in Table-2.

 The silicon wafer contaminated with this metal was cleaned by immersing it in a cleaning solution for 10 minutes at room temperature to remove the metal. The cleaning solution was an aqueous solution containing a surfactant and hydrofluoric acid at a predetermined concentration as shown in Table 2 and an acid other than hydrofluoric acid was added so as to obtain the pH shown in Table 12. A washing solution composed of an aqueous solution was used.

 The washed silicon wafer was washed with ultrapure water for 10 minutes and dried by blowing nitrogen to obtain a washed silicon wafer.

The Fe, Al, and Cu remaining on the surface of the obtained cleaned silicon wafer were quantified, and the substrate surface concentration was calculated. The substrate surface concentration (atoms / cm ² ) was shown by the average value of the two silicon wafers that had been cleaned and the substrate surface concentration (atoms / cm ² ) of each substrate was measured for each metal. . The results are shown in Table-2. In the present invention, quantification of Fe, Al, and Cu attached to the silicon wafer surface was performed as follows.

Fe, A1, and Cu attached to the surface of the silicon wafer were recovered using a mixed solution of 0.1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide. The amounts of Fe, A1, and Cu contained in this solution were measured by a flameless atomic absorption method, and were converted to the substrate surface concentration (atoms / cm ² ). Table 1 2

_{* 1: C 12 H 25 -ph} -S0 3 H (. Incidentally, one ph- represents a phenylene group) ※ in the table, abbreviated as "hydrofluoric acid" hydrofluoric acid.

Industrial applicability

 According to the cleaning method of the present invention, it is possible to achieve a highly clean substrate surface free of contamination without corroding a metal member made of a transition metal or a transition metal compound or the like and without irradiating ultrasonic waves. It is very useful industrially.

Claims

The scope of the claims 1. A cleaning solution for a semiconductor device substrate having a transition metal or a transition metal compound on a surface, the cleaning solution comprising a solution selected from the group consisting of the following (A1), (A2) and (A3). Cleaning liquid for a semiconductor device substrate having a transition metal or a transition metal compound on the surface of the substrate. _{(A 1) - S 0 3} - surfactant having a group (excluding sulfosuccinate diester Le compounds) comprises, pH is 3 or less solution  (A2) A solution containing a surfactant consisting of a methyl phosphate compound (A3) -0 S 0 ₃ - comprises a surfactant comprising a surfactant and / or sulfosuccinic acid di ester compound having a group, solution p H is 4 or more 2. The cleaning solution for a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof according to claim 1, wherein the cleaning solution comprises a solution (A1) and / or a solution (A2). 3. The cleaning liquid for a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof according to claim 2, wherein the cleaning liquid is a solution (A1). 4. The 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 3, wherein the pH of the solution (A1) is 2 or less. Cleaning solution. 5. contained in the solution (A 1) - one type surfactant having a group selected from the group consisting of methyl evening Urin acid compounds, alkylbenzenesulfonic acid compounds and alkyl di-phenylalanine ether disulfonic acid compound - S 0 ₃ The surface according to any one of claims 1 to 4, characterized in that: A cleaning solution for a semiconductor device substrate having a transition metal or a transition metal compound. . 6 solution (A 1) from consisting of washing liquid - S 0 ₃ - concentration of the surface active agent having a group characterized in that it is a 0 0 0 1-1% by weight with respect to the cleaning liquid during substrate cleaning. 6. 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 claims 1 to 5. 7. The cleaning solution for a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof according to claim 2, wherein the cleaning solution comprises a solution (A 2). 8. The method according to claim 1, wherein the concentration of the surfactant comprising a methyltauric acid compound in the cleaning solution comprising the solution (A 2) is 0.001-1% 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 a surface according to any one of Items 1, 2, and 7. 9. The cleaning liquid has a transition metal or a transition metal compound on the surface according to any one of claims 1 to 8, further comprising hydrofluoric acid and / or ammonium fluoride. Cleaning solution for semiconductor device substrates. 10. The semiconductor device having a transition metal or a transition metal compound on a surface according to any one of claims 1 to 9, wherein the cleaning liquid further contains an acid other than hydrofluoric acid. Cleaning liquid for substrate. 11. The semiconductor device having a transition metal or a transition metal compound on the surface according to any one of claims 1 to 10, wherein the transition metal or the transition metal compound is copper or tungsten. Cleaning liquid for substrate. 12. A cleaning solution for a substrate having silicon or silicon oxide on its surface, which is a solution containing a surfactant composed of a methyl phosphoric 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, the method comprising at least one solution selected from the group consisting of (A1), (A2) and (A3) below. A method for cleaning a substrate for a semiconductor device having a transition metal or a transition metal compound on a surface thereof. _{(A 1) - S 0 3} - surfactant having a group (excluding sulfosuccinate diester Le acids) comprise, pH is 3 or less solution  (A 2) A solution containing a surfactant comprising a methyl phosphate compound _{(A3) - 0 S 0 3} - comprises a surfactant and / or sulfosuccinic acid di ester compound having a group, the solution pH is 4 or more 14. The method for cleaning a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof according to claim 13, wherein the cleaning liquid is (A 1) and / or (A 2). 15. The method for cleaning a semiconductor device substrate 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 solution according to claim 13, wherein the pH of the solution (A 1) is 2 or less, for a semiconductor device having a transition metal or a transition metal compound on a surface thereof. Substrate cleaning method. 17. The surfactant having a —SO ₃ — group contained in the solution (A 1) is selected from the group consisting of a methyl phosphoric acid compound, an alkylbenzene sulfonic acid compound, and an alkyl diphenyl ether disulfonic acid compound. Above 17. 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 16 characterized by the following. . 1 8 washing solution (A 1) in the -S 0 ₃ - claims the concentration of surfactant having a group characterized in that it is a 0 0 0 1-1% by weight with respect to the cleaning liquid during board cleaning. 18. 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 items 13 to 17. 19. The method for cleaning a semiconductor device substrate having a transition metal or a transition metal compound on a surface thereof according to claim 14, wherein the cleaning liquid is (A 2). 20. The concentration of the surfactant comprising a methyltauric acid compound in the solution (A 2) is 0.001-1% by weight with respect to the cleaning solution when the substrate is cleaned. 10. 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, 14 and 19. 21. The cleaning liquid according to any one of claims 13 to 20, wherein the cleaning liquid further contains hydrofluoric acid and / or ammonium fluoride. A method for cleaning a semiconductor device substrate having a metal compound. 22. The cleaning liquid according to claim 13, wherein the cleaning liquid further contains an acid other than hydrofluoric acid. The cleaning liquid has a transition metal or a transition metal compound on a surface thereof. A method for cleaning a substrate for a semiconductor device. 23. The transition to the surface according to any one of claims 13 to 22, wherein the transition metal or the transition metal compound is copper or tungsten. A method for cleaning a semiconductor device substrate having a metal or a transition metal compound. 24. The surface according to any one of claims 13 to 23, wherein the cleaning of the semiconductor device having a transition metal or a transition metal compound on the surface is performed without irradiating ultrasonic waves. CLEANING METHOD FOR SEMICONDUCTOR DEVICE SUBSTRATE HAVING TRANSITION METALS OR TRANSITION METAL COMPOUNDS. 25. A method for cleaning a substrate having silicon or silicon oxide on its surface, comprising using a solution containing a surfactant composed of a methyl phosphoric acid-based compound.