JPH09157692A - Surface-treating composition and treatment of surface of substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface-treating composition capable of preventing metal impurities contained therein from contaminating the surface of a substrate and constantly achieving the extremely clean surface of the substrate, and to provide a method for treating the substrate surface with the surface-treating composition. SOLUTION: This surface-treating composition comprises a liquid medium and a complexing agent contained in the liquid medium as a metal adhesion- preventing agent. Therein, the complexing agent comprises at least one selected from among (A group) complexing agents having a ring skeleton in the molecular structure and one or more of OH groups and/or O-groups bound to carbon atoms constituting the ring (e.g. tiron) and at least a complexing agent selected from among (B group) carboxylic acid-based complexing agents (e.g. acetic acid, malonic acid) having one or more carboxylic groups, not having nitrogen, halogen, sulfur and carbon atoms as donor atoms, and not having carbonyl and hydroxyl groups in the molecular structure.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a surface treatment composition and a method for treating a surface of a substrate using the same. More specifically, when performing surface treatment of a substrate using a surface treatment composition mainly composed of a liquid medium, contamination of the surface of the substrate by metal impurities from the surface treatment composition is prevented, and extremely stable and extremely clean. The present invention relates to a surface treatment composition capable of achieving a stable substrate surface and a method for treating a substrate surface using the same.

[0002]

2. Description of the Related Art With the high integration of various devices represented by ultra LSIs and TFT liquid crystals, the demand for cleaning the surface of a substrate used in the devices has become increasingly severe. Contamination by various substances is one of the obstacles to cleaning, and among these, the contamination by metal particularly deteriorates the electrical characteristics of the device.To prevent such degradation, the metal on the substrate surface on which the device is formed is to be prevented. It is necessary to reduce the concentration of impurities as much as possible. Therefore, it is common practice to clean the substrate surface with a cleaning agent.

Conventionally, water, electrolytic ionized water, aqueous solutions of acids, alkalis, oxidizing agents, surfactants, etc., or organic solvents have been generally used for this type of cleaning agent. In addition to excellent cleaning performance, the cleaning agent is required to have an extremely low impurity concentration in the cleaning agent in order to prevent reverse contamination of the substrate from the cleaning agent by metal impurities. In order to satisfy such demands, purification of semiconductor chemicals used for cleaning has been promoted, and the concentration of metal impurities contained in the chemicals immediately after purification has reached a level that is difficult to detect with current analysis techniques. In this way, it is still difficult to achieve a highly clean substrate surface even if the impurities in the cleaning agent have reached a level that is difficult to detect. This is because it is inevitable to contaminate the cleaning agent itself. That is, the metal impurities once detached from the surface of the base are mixed in the cleaning agent to contaminate the cleaning agent, and the metal impurities from the contaminated cleaning agent adhere to the substrate (reverse contamination).

In the semiconductor cleaning process, cleaning with an [ammonia + hydrogen peroxide + water] solution (SC-1 cleaning)
(RCA Review, p.187-206, June (1970), etc.) is widely used. The main cleaning is usually performed at 40 to 90 ° C.
The composition ratio in the solution is usually (30% by weight aqueous ammonia): (31% by weight aqueous hydrogen peroxide): (water) = 0.0.
It has been used for about 5: 1: 5 to 1: 1: 5. However, this cleaning method has high particle removal ability and organic matter removal ability, but when a very small amount of metal such as Fe, Al, Zn, and Ni is present in the solution, it adheres to the substrate surface and causes reverse contamination. There is. Therefore, in the semiconductor cleaning process, [ammonia + hydrogen peroxide + water] is usually used.
After the solution cleaning, cleaning with an acidic cleaning agent such as [hydrochloric acid + hydrogen peroxide + water] solution cleaning (SC-2 cleaning) is performed to remove metal contamination on the substrate surface. Therefore, in the cleaning process, a technique for preventing such reverse contamination has been required in order to efficiently and stably obtain a highly clean surface.

Further, the problem that the metal impurities in the liquid adhere to the surface of the substrate is not limited to the cleaning step, but the substrate using the solution is not only the cleaning step but also the alkali etching of the silicon substrate and the etching step of the silicon oxide film with dilute hydrofluoric acid. It is a big problem in the overall surface treatment process. In the diluted hydrofluoric acid etching step, if there is a noble metal impurity such as Cu or Au in the liquid, it adheres to the silicon surface and significantly degrades the electrical characteristics of the device such as carrier lifetime. Further, in the alkali etching step, if trace amounts of metallic impurities such as Fe and Al are present in the liquid, these easily adhere to the surface of the substrate, which adversely affects the quality. Therefore, a technique for preventing such contamination in a surface treatment step using a solution is also strongly demanded.

In order to solve these problems, a complexing agent such as a chelating agent is added to the surface treatment agent to capture metal impurities in the solution as a stable water-soluble complex and prevent adhesion to the substrate surface. A method has been proposed. For example, Japanese Patent Application Laid-Open
In 158281, ammonium cyanide or ethylenediamine 4 was added to an aqueous solution of tetraalkyl ammonium hydroxide.
It has been proposed to add a complexing agent such as acetic acid (EDTA) to prevent metal impurities from adhering to the surface of the semiconductor substrate. In JP-A-3-219000, chelating agents such as catechol and Tyrone, in JP-A-5-275405, phosphonic acid-based chelating agents or complexing agents such as condensed phosphoric acid, and JP-A-6-16.
In 3495, a complexing agent such as a hydrazone derivative is added to an alkaline cleaning liquid such as [ammonia + hydrogen peroxide + water] to prevent metal impurities from adhering to the substrate, and thereby to prevent metal contamination with particles and organic substances. It is proposed to achieve a substrate surface without any.

However, when these complexing agents are added, the effect of preventing or removing specific metals (for example, Fe) is observed, but metals other than Fe (which are likely to contaminate the processing liquid or the substrate) ( For example, with respect to Al), the effect of the complexing agent is extremely small, and there is a problem that a sufficient effect cannot be obtained even if a large amount of complexing agent is added. To solve this problem, JP-A-6-216098
Proposes a method of cleaning the substrate with a cleaning solution [ammonia + hydrogen peroxide + water] to which a chelating agent such as a phosphonic acid chelating agent is added, and then rinsing with a hydrofluoric acid aqueous solution of 1 ppm or more. Since a cleaning liquid containing a phosphonic acid-based chelating agent cannot sufficiently reduce Al contamination on the substrate surface, it is intended to remove Al by etching using a hydrofluoric acid aqueous solution of 1 ppm or more in a subsequent step. As described above, the conventional metal adhesion preventing method is not effective enough, and when the substrate needs to be cleaned, the metal contamination must be removed in a later process, thereby increasing the number of processes. Therefore, this has caused an increase in production costs. As described above, in order to prevent the contamination of metal impurities from the surface treatment composition to the surface of the substrate, the addition of various complexing agents has been attempted to prevent the adhesion, but no sufficient improvement has been made yet.
Pollution control technology has not been achieved yet.

[0008]

The present invention has been made to solve the above problems, and prevents contamination of metal impurities from the surface treatment composition to the surface of the substrate, and provides a stable and extremely clean substrate surface. It is an object of the present invention to provide a surface treatment composition capable of achieving the above and a method for surface treatment of a substrate using the same.

[0009]

According to the present invention, when two or more specific complexing agents are added as a metal adhesion preventive agent in a surface treatment composition, compared with the case where there is one complexing agent, This has been achieved based on the new finding that the effect of preventing the adhesion of metal impurities from the treatment liquid to the substrate is significantly improved.
That is, the gist of the present invention is a surface treatment composition containing a complexing agent as a metal adhesion inhibitor in a liquid medium, wherein the complexing agent has a cyclic skeleton in the (A group) molecular structure, and OH groups and / or bonded to the carbon atoms constituting the ring O ^- complexing agent having one or more groups, and have (B group) one or more carboxyl groups in its molecular structure, a nitrogen atom as a donor atom , A surface treatment composition comprising at least one complexing agent selected from the group consisting of carboxylic acid-based complexing agents having no halogen atom, sulfur atom and carbon atom, and having no carbonyl group or hydroxyl group, and the surface thereof A method of treating the surface of a substrate using the treatment composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The surface treatment composition of the present invention is characterized by containing therein two or more specific complexing agents as metal adhesion preventing agents. The specific two or more complexing agents are composed of one or more complexing agents selected from the group A and one or more complexing agents selected from the group B defined below. Incidentally, the surface treatment composition in the present invention means a substrate cleaning,
It is a general term for surface treatment agents used for the purpose of etching, polishing, film formation and the like.

The group A complexing agent is a complexing agent having a cyclic skeleton in its molecular structure and having at least one OH group and / or O ⁻ group bonded to the carbon atoms constituting the ring. is there. The cyclic skeleton in the molecular structure may be any of cyclic skeletons corresponding to an alicyclic compound, an aromatic compound or a heterocyclic compound, and one or more of these cyclic skeletons are present in the molecular structure. O bound to the carbon atoms that make up
It has at least one H group and / or O ⁻ group. Specific examples of such a complexing agent include the following, but are not particularly limited thereto. Also,
Specific examples are illustrated as compounds having an OH group, but also include corresponding salts such as ammonium salts and alkali metal salts thereof.

(1) Phenols having only one OH group and derivatives thereof Phenol, cresol, ethylphenol, t-butylphenol, methoxyphenol, salicyl alcohol, chlorophenol, aminophenol, aminocresol, amidole, p- (2 -Aminoethyl) phenol, salicylic acid, o-salicylanilide, naphthol, naphtholsulfonic acid, 7-amino-4-hydroxy-2-naphthalenedisulfonic acid and the like.

(2) Phenols having two or more OH groups and derivatives thereof Catechol, resorcinol, hydroquinone, 4-methylpyrocatechol, 2-methylhydroquinone, pyrogallol, 1,2,5-benzenetriol, 1,3,3. 5-
Benzenetriol, 2-methylphloroglucinol,
2,4,6-trimethylphloroglucinol, 1,2,2
3,5-benzenetetraol, benzenehexaol, Tyrone, aminoresorcinol, 2,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, dihydroxyacetophenone, 3,4-dihydroxybenzoic acid, gallic acid, 2,3,4 -Trihydroxybenzoic acid, 2,4-dihydroxy-6-methylbenzoic acid, naphthalenediol, naphthalenetriol,
Nitronaphthol, naphthalenetetraol, binaphthyldiol, 4,5-dihydroxy-2,7-naphthalenedisulfonic acid, 1,8-dihydroxy-3,6-naphthalenedisulfonic acid, 1,2,3-anthracentriol, 1,3 , 5-Tris [((2,3-dihydroxybenzoyl) amino) methyl) benzene] [MECA
M], 1,5,10-tris (2,3-dihydroxybenzoyl) -1,5,10-triazadecane [3,4-
LICAM], 1,5,9-tris (2,3-dihydroxybenzoyl) -1,5,9-cyclotriazatridecane [commonly known as 3,3,4-CYCAM], 1,3,5-
Tris [(2,3-dihydroxybenzoyl) carbamide] benzene [TRIMCAM], enterobactin,
Enanthus enterobactin etc.

(3) Hydroxybenzophenones Dihydroxybenzophenones, 2,3,4-trihydroxybenzophenones, 2,6-dihydroxy-4-methoxybenzophenones, 2,2 ', 5,6'-tetrahydroxybenzophenones, 2,3 ', 4,4', 6-pentahydroxybenzophenone and the like.

(4) Hydroxybenzanilide O-hydroxybenzanilide and the like. (5) Hydroxyanil Glyoxal bis (2-hydroxyanyl) and the like. (6) Hydroxybiphenyls Biphenyltetraol and the like.

(7) Hydroxyquinones and derivatives thereof 2,3-dihydroxy-1,4-naphthoquinone, 5-hydroxy-1,4-naphthoquinone, dihydroxyanthraquinone, 1,2-dihydroxy-3- (aminomethyl) anthraquinone -N, N'-2 acetic acid [alizarin complexan], trihydroxy anthraquinone, etc.

(8) Diphenyl or triphenylalkane derivative Diphenylmethane-2,2'-diol, 4,4 ',
4 "-triphenylmethanetriol, 4,4'-dihydroxyfuchsone, 4,4'-dihydroxy-3-methylfuchsone, pyrocatechol violet [PV] and the like.

(9) Phenol derivative of alkylamine Ethylenediaminedioltohydroxyphenylacetic acid [E
DDHA], N, N-bis (2-hydroxybenzyl)
Ethylenediamine-N, N-2acetic acid [HBED], ethylenediaminedihydroxymethylphenylacetic acid [EDD
HMA] etc.

(10) Phenol derivative of alkyl ether 3,3'-ethylenedioxydiphenol and the like.

(11) Phenols having an azo group and derivatives thereof 4,4'-bis (3,4-dihydroxyphenylazo)
-Diammonium 2,2'-stilbene disulfonic acid [stilbazo], 2,8-dihydroxy-1- (8-hydroxy-3,6-disulfo-1-naphthylazo)-
3,6-naphthalenedisulfonic acid, o, o'-dihydroxyazobenzene, 2-hydroxy-1- (2-hydroxy-5-methylphenylazo) -4-naphthalenesulfonic acid [calmagite], chlorohydroxyphenylazonaphthol, 1 '2-dihydroxy-6-nitro-
1,2′-azonaphthalene-4-sulfonic acid [Eriochrome Black T], 2-hydroxy-1- (2-hydroxy-4-sulfo-1-naphthylazo) -3,6-
Naphthalenedisulfonic acid, 5-chloro-2-hydroxy-3- (2,4-dihydroxyphenylazo) benzenesulfonic acid [lumogallion], 2-hydroxy-1
-(2-hydroxy-4-sulfo-1-naphthylazo)
-3-Naphthalene acid [NN], 1,8-dihydroxy-
2- (4-sulfophenylazo) -3,6-naphthalenedisulfonic acid, 1,8-dihydroxy-2,7-bis (5-chloro-2-hydroxy-3-sulfophenylazo) -3,6-naphthalene Disulfonic acid, 1,8-dihydroxy-2,7-bis (2-sulfophenylazo)-
3,6-naphthalenedisulfonic acid, 2- [3- (2,4
-Dimethylphenylaminocarboxy) -2-hydroxy-1-naphthylazo] -3-hydroxybenzenesulfonic acid, 2- [3- (2,4-dimethylphenylaminocarboxy) -2-hydroxy-1-naphthylazo] phenol and the like.

(12) Heterocyclic compounds having an OH group and derivatives thereof 8-quinolinol, 2-methyl-8-quinolinol, quinolinediol, 1- (2-pyridylazo) -2-naphthol, 2-amino-4 , 6,7-Pteridinetriol, 5,7,3′4′-tetrahydroxyflavone [luteolin], 3,3′-bis [N, N-bis (carboxymethyl) aminomethyl] fluorescein [calcein], 2, 3-hydroxypyridine and the like.

(13) Cycloaliphatic compounds having OH group and derivatives thereof: cyclopentanol, croconic acid, cyclohexanol, cyclohexanediol, dihydroxydiquinoyl, tropolone, 6-isopropyltropolone and the like.

The surface treatment composition of the present invention must contain at least one complexing agent selected from the above-mentioned group A as a metal adhesion preventing agent. When selecting a complexing agent, it is necessary to make a comprehensive judgment based on the level of cleanliness required for the substrate surface, the cost of the complexing agent, the chemical stability in the surface treatment composition to be added, and so on. Although it cannot be said that any of the complexing agents is the best, ethylenediamine diorthohydroxyphenylacetic acid [EDDH] is particularly preferable in terms of the effect of preventing metal adhesion when the content in the surface treatment composition is constant.
Phenol derivatives of alkylamines such as A] and phenols having two or more OH groups such as catechol and Tyrone and their derivatives are excellent and are preferably used. In addition, in terms of chemical stability, phenol derivatives of alkylamines such as ethylenediaminedioltohydroxyphenylacetic acid [EDDHA] are excellent, and in terms of production cost of complexing agents, 8-quinolinol, catechol, Tyrone, etc. are each It is excellent and is preferably used when these are important. Furthermore, it is preferable that the complexing agent has a sulfonic acid group and a carboxyl group in addition to the OH group, because both the metal adhesion preventing effect and the chemical stability are excellent.

The group B complexing agent is a complexing agent having at least one carboxyl group in its molecular structure but not having a donor atom such as a nitrogen atom, a halogen atom, a sulfur atom or a carbon atom, and a carbonyl group or a hydroxyl group. It is a carboxylic acid type complexing agent characterized by not containing any of the above. In the present invention,
A donor atom is an atom that can supply electrons necessary for coordination bond with a metal. Specific examples of the complexing agent of group B include those shown below, but the complexing agent is not particularly limited thereto. Further, carboxylic acids are exemplified as free acids, but salts such as ammonium salts and alkali metal salts thereof are also included.

(1) Monocarboxylic acids Formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid,
Decanoic acid, undecanoic acid, dodecanoic acid, stearic acid,
Acrylic acid, crotonic acid, oleic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, fluoroacetic acid, benzoic acid, methylbenzoic acid, chlorobenzoic acid, sulfocarboxylic acid, phenylacetic acid, etc.

(2) Polycarboxylic acids Oxalic acid, malonic acid, succinic acid, maleic acid, fumaric acid, 1,2,3-propanetricarboxylic acid, chlorosuccinic acid, phthalic acid, 1,3,5-benzenetricarboxylic acid, Dichlorophthalic acid, phenylsuccinic acid, etc. B above
Among the group, particularly, carboxylic acids having a relatively simple structure such as acetic acid and oxalic acid, that is, aliphatic saturated carboxylic acids having 2 to 3 carbon atoms, are excellent in both the metal adhesion preventing effect and the cost, and are preferably used.

Further, in the present invention, the above-mentioned groups A and B
In addition to the complexing agents of the group, the fourth as a metal adhesion preventing agent
It is preferable to add a graded ammonium salt because the effect of preventing metal adhesion is further improved. Examples of the quaternary ammonium salt include quaternary ammonium hydroxide having a lower alkyl group and a hydroxy lower alkyl group, and specifically, tetramethylammonium hydroxide [TM
AH], trimethyl-2-hydroxyethylammonium hydroxide [choline] and the like can be mentioned, but the invention is not particularly limited thereto. Although the amount of the quaternary ammonium salt used varies depending on the type of the salt, it is usually 10 ^−7.
About 0.1% by weight.

The amount of the complexing agent added as the metal adhesion preventing agent is determined in a general manner because it depends on the type and quantity of the metal impurities in the liquid which is the object of adhesion prevention, and the level of cleanliness required on the substrate surface. However, the total amount added in the surface treatment composition is usually 10 ⁻⁷ to 2% by weight, preferably 10 ^{−7.
-6 to} 0.1% by weight. If the addition amount is too small, the effect of preventing metal adhesion, which is the object of the present invention, is difficult to be exhibited.On the other hand, even if the amount is too large, not only no further effect is obtained, but also, in some cases, a metal adhesion inhibitor is applied to the surface of the substrate. It is not preferable because the risk of attaching a certain complexing agent increases.

The liquid medium as the main component in the surface treatment composition of the present invention is not particularly limited, but usually water, electrolytic ion water, acid, alkali, oxidizing agent, reducing agent, surfactant, etc. are dissolved. An aqueous solution, an organic solvent, or a mixed solution thereof is used. In particular, in the case of an alkaline aqueous solution or a diluted hydrofluoric acid solution used for cleaning or etching of a semiconductor substrate, since a metal impurity in the solution is very easily attached to the substrate surface, a complexing agent is added to these solutions according to the present invention. It is preferable to use it.

The alkaline aqueous solution used in the present invention is a generic term for aqueous solutions having a pH of more than 7. The alkaline component of this aqueous solution is not particularly limited, but a typical one is ammonia. Further, hydroxides of alkali metals or alkaline earth metals such as sodium hydroxide, potassium hydroxide and calcium hydroxide, alkaline salts such as sodium hydrogencarbonate and ammonium hydrogencarbonate, tetramethylammonium hydroxide (TMAH) and trimethyl. 4-Hydroxyethylammonium hydroxide [choline] etc.
A graded ammonium salt hydroxide and the like are also used. There is no problem even if two or more kinds of these alkalis are added, and usually the total concentration in the total solution of the surface treatment composition is 0.
It is used in an amount of 01 to 30% by weight, preferably 0.1 to 10% by weight. Further, alkaline electrolytic ionic water obtained by electrolysis of water is also preferably used. further,
An oxidizing agent such as hydrogen peroxide may be appropriately compounded in such an alkaline aqueous solution. When cleaning bare (no oxide film) silicon in the semiconductor wafer cleaning process, the mixing of the oxidizing agent can suppress the etching and surface roughness of the wafer. When hydrogen peroxide is blended with the alkaline aqueous solution of the present invention, it is usually used so that the concentration of hydrogen peroxide in the entire solution of the surface treatment composition is in the range of 0.01 to 30% by weight.

The method of adding the complexing agent according to the present invention to the surface treatment composition is not particularly limited. Of the components constituting the surface treatment composition (for example, aqueous ammonia, aqueous hydrogen peroxide, water, etc.), any one or more of the components are preliminarily blended, and then these components are mixed and used. Alternatively, the components may be mixed and then mixed with the mixture before use. When acids such as phenols and carboxylic acids are added and contained, these may be added in the form of acid or in the form of salt such as ammonium salt.

The surface treatment composition of the present invention is used for cleaning, etching, polishing, film-forming, etc. of substrates such as semiconductors, metals, glass, ceramics, plastics, magnetic materials and superconductors in which contamination of the substrate with metal impurities is a problem. It is used for the surface treatment of. In particular, the present invention is suitably used for cleaning and etching of a semiconductor substrate requiring a highly clean substrate surface. Among the cleaning of semiconductor substrates, in particular, [ammonia + hydrogen peroxide +
When the present invention is applied to the alkaline cleaning using a cleaning solution comprising water, the problem of the metal impurities adhering to the substrate, which was a problem of the cleaning method, is improved. It is very suitable because a clean and clean substrate surface is achieved.

The reason why the surface-treating composition of the present invention exerts an extremely good effect in preventing the adhesion of metal impurities is not yet clear, but it is not possible to clarify the reason why two or more specific complexing agents and metal ions are added. It is presumed that some kind of mixing effect occurs during this period and a stable water-soluble metal complex is formed extremely effectively.

When the surface treatment composition of the present invention is used as a cleaning liquid for cleaning a substrate, a method of directly contacting the liquid with the substrate is used. Such cleaning methods include dip-type cleaning in which a cleaning tank is filled with a cleaning liquid to immerse the substrate, spray-type cleaning in which the liquid is sprayed on the substrate to clean the substrate, and spin-type cleaning in which the cleaning liquid is dropped on the substrate and rotated at high speed. And the like. In the present invention, among the above-mentioned cleaning methods, an appropriate one is adopted depending on the purpose, but dip type cleaning is preferably used. Regarding the washing time, the washing is carried out for an appropriate time, preferably 10 seconds to 30 minutes, more preferably 30 seconds to 15
Minutes. If the time is too short, the cleaning effect will not be sufficient, and if it is too long, the throughput will only be deteriorated, and the cleaning effect will not increase and is meaningless. The washing may be performed at room temperature, but may be performed with heating for the purpose of improving the washing effect. Further, at the time of cleaning, a cleaning method using physical force may be used in combination. Examples of such a cleaning method using physical force include ultrasonic cleaning and mechanical cleaning using a cleaning brush.

[0035]

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 5 and Comparative Examples 1 to 9 Ammonia water (30% by weight), hydrogen peroxide solution (31% by weight) and water were mixed at a volume ratio of 0.25: 1: 5, and the obtained mixture was obtained. A solution is used as a main component of an aqueous solvent, and a predetermined amount of two or more specific complexing agents of the present invention shown in Table 1 as metal adhesion inhibitors are added to the aqueous solvent in a predetermined amount, and the surface treatment composition of the present invention is added. The thing was prepared. For comparison, one of the complexing agents used in the examples was added to the aqueous solvent, and the complexing agents catechol, tyron, and catechol + described in JP-A-3-2199000. ED containing citric acid, which is the complexing agent described in JP-A-5-275405
Addition of TPO [ethylenediaminetetrakis (methylphosphonic acid)], addition of oxalic bis (salicylidene hydrazide) which is a complexing agent described in JP-A-6-163495, and addition of no complexing agent Also prepared.

After adding 10 ppb each of Al and Fe as chlorides to the surface treatment liquid thus prepared,
Clean silicon wafer (p-type, CZ, plane orientation (10
0)) was soaked for 10 minutes. During the immersion, the temperature of the surface treatment liquid was maintained at 40 to 50 ° C. by heating. The silicon wafer after the immersion was subjected to overflow rinse with ultrapure water for 10 minutes and then dried by nitrogen blowing to quantify Al and Fe adhering to the wafer surface. Al and Fe adhering to the silicon wafer are recovered with a mixed solution of 0.1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide, and the amount of the metal is measured by a flameless atomic absorption method to determine the substrate surface concentration (atoms / It was converted to cm ² ). Table 1 shows the results.

[0037]

[Table 1]

Example 6 and Comparative Example 10 A mixed solution obtained by mixing ammonia water (30% by weight), hydrogen peroxide solution (31% by weight) and water at a volume ratio of 1: 1 was the main component. Was added to the aqueous solvent as a metal adhesion inhibitor, and a predetermined amount of each of the two specific complexing agents of the present invention shown in Table 2 was added to the aqueous solvent to prepare the surface treatment composition of the present invention. For comparison, a solution was also prepared in which no complexing agent was added to the aqueous solvent. A silicon wafer whose surface was contaminated with metal (p
The mold, CZ, and plane orientation (100) were immersed for 10 minutes to wash the metal-contaminated surface. During the immersion, the temperature of the surface treatment liquid is
Warmed and maintained at 40-50 ° C. The silicon wafer after the immersion was subjected to overflow rinse with ultrapure water for 10 minutes and then dried by nitrogen blowing to quantify the metal on the wafer surface. The metal on the surface of the silicon wafer is recovered with a mixed solution of 0.1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide, and the amount of the metal is measured by a flameless atomic absorption method to determine the substrate surface concentration (atoms / cm ² ). Converted to. Table 2 shows the results.

[0039]

[Table 2]

As shown in Table 2, when the substrate is treated with the surface treatment liquid of the present invention, not only the metal is prevented from adhering to the substrate surface from the liquid, but the substrate surface is contaminated with the metal. In some cases, metal contamination can be removed.

[0041]

The surface treatment composition of the present invention contains two or more specific complexing agents as a metal adhesion preventive agent, so that metal impurities such as Al and Fe from the surface treatment composition to the surface of the substrate can be contained. It is possible to prevent contamination and stably achieve an extremely clean substrate surface. In particular, when the present invention is applied to alkali cleaning of a semiconductor substrate represented by [ammonia + hydrogen peroxide + water] cleaning, the problem of metal impurities adhering to the substrate, which is a problem of the cleaning method, is improved, As a result, the cleaning achieves a highly clean substrate surface free from metal contamination as well as particles and organic substances. Therefore, acid cleaning such as [hydrochloric acid + hydrogen peroxide + water] cleaning conventionally used after the cleaning can be omitted, and the cleaning cost and the cost of the clean room such as exhaust equipment can be significantly reduced. Therefore, it is a great advantage for industrial production of semiconductor integrated circuits.

When manufacturing devices such as semiconductors and liquid crystals,
In a wet process such as etching and cleaning, ultrapure water and ultrahigh-purity chemicals having a metal impurity concentration of 0.1 ppb or less are used to prevent metal impurities from adhering to the substrate surface. Furthermore, these chemicals need to be replaced frequently because metal impurities are mixed during use. However, if the surface treatment composition of the present invention is used, it is possible to prevent adhesion even if a large amount of metal impurities are present in the liquid, so there is no need to use an ultra-high purity chemical liquid, and the chemical liquid is used. Even if it is contaminated with metal impurities, it does not need to be replaced frequently, so the cost of the chemical solution and its management can be greatly reduced.

When etching or cleaning a substrate having a metal on the surface, if a metal having a higher ionization tendency than the metal to be treated is present as an impurity in the cleaning liquid, it is electrochemically attached to the substrate surface. When the composition of the present invention is used, metal impurities become a stable water-soluble metal complex, which can be prevented. Further, when the composition of the present invention is applied to an abrasive slurry for polishing a substrate, it is possible to prevent metal impurities, which are present in a large amount in the abrasive slurry and are concentrated in the slurry as the substrate is polished, from adhering to the substrate. As described above, the ripple effect of the surface treatment agent of the present invention is tremendous,
Very useful industrially.

Claims (9)

[Claims] 1. In a surface treatment composition containing a complexing agent as a metal adhesion preventing agent in a liquid medium, the complexing agent comprises (A)
(Group) A complexing agent having a cyclic skeleton in the molecular structure and having one or more OH groups and / or O ⁻ groups bonded to carbon atoms constituting the ring, and (Group B) a carboxyl group in the molecular structure. At least one member selected from each group of carboxylic acid-based complexing agents having one or more groups but not having a nitrogen atom, a halogen atom, a sulfur atom and a carbon atom which are donor atoms, and having no carbonyl group and hydroxyl group. A surface treatment composition comprising a complexing agent selected. 2. The group A complexing agent is an OH group and / or O ^−.
Has at least two groups, and the group B complexing agent has 2 to 3 carbon atoms.
The surface treatment composition according to claim 1, which is selected from the saturated aliphatic mono- or dicarboxylic acids or salts thereof. 3. At least one member from each of the groups A and B
The surface treatment composition according to any one of claims 1 and 2, which further comprises a quaternary ammonium salt together with a complexing agent selected from species. 4. The quaternary ammonium salt is a quaternary ammonium hydroxide having a lower alkyl group and / or a hydroxy lower alkyl group.
The surface treatment composition according to. 5. The content of the metal adhesion preventive agent is 10 ^{−6 to} 0.1.
The surface treatment composition according to any one of claims 1 to 4, wherein the surface treatment composition is wt%. 6. The surface treatment composition according to any one of claims 1 to 5, wherein the liquid medium is an alkaline aqueous solution. 7. The surface treatment composition according to claim 6, wherein the alkaline aqueous solution contains ammonia and hydrogen peroxide. 8. A method for treating a surface of a substrate, which comprises subjecting the substrate to a surface treatment using the surface treatment composition according to any one of claims 1 to 7. 9. The method for surface treatment of a substrate according to claim 8, wherein the substrate is a semiconductor substrate.