JP3228211B2 - Surface treatment composition and substrate surface treatment method using the same - Google Patents

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.
Furthermore, the present invention relates to a method for replenishing the components of the surface treatment composition and a method for purifying a complexing agent used in the composition.

[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. There is contamination by various substances that hinders cleaning, and among them, metal contamination in particular degrades the electrical characteristics of the device. It is necessary to reduce the concentration of metal impurities as much as possible. Therefore, it is common practice to clean the substrate surface with a cleaning agent.

Conventionally, this type of cleaning agent includes aqueous solutions of water, electrolytic ionized water, acids, alkalis, oxidizing agents, surfactants, and the like.
Alternatively, an organic solvent or the like is generally used. 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 with 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.

[0004] As described above, despite the fact that the impurities in the cleaning agent have reached a level that is difficult to detect, it is still difficult to achieve a high-purity substrate surface in the cleaning tank due to the metal removed from the substrate. This is because impurities inevitably 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 step, cleaning with [ammonia + hydrogen peroxide + water] solution (SC-1 cleaning)
(RCA Review, p.187-206, June (1970), etc.) are 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) = 0.05.
１ ： 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. For this reason, in the semiconductor cleaning step, cleaning with an acidic cleaning agent such as a [hydrochloric acid + hydrogen peroxide + water] solution cleaning (SC-2 cleaning) is usually performed after the [ammonia + hydrogen peroxide + water] solution cleaning. This removes metal contamination on the substrate surface.

Therefore, in the cleaning step, a technique for preventing such reverse contamination has been required in order to efficiently and stably obtain a highly clean surface. Furthermore, the problem that metal impurities in the liquid adhere to the substrate surface is not only a cleaning process, but also a substrate surface treatment process using a solution such as an alkali etching of a silicon substrate or an etching process of a silicon oxide film with diluted hydrofluoric acid. This is a major problem in general. 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. In the alkaline etching step, Fe
If trace metal impurities such as Al and Al are present, they easily adhere to the substrate surface, 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 treating agent to trap metal impurities in the liquid as a stable water-soluble complex, thereby preventing adhesion to the substrate surface. A method has been proposed. For example, Japanese Patent Application Laid-Open
158281 proposes adding a complexing agent such as ammonium cyanide or ethylenediaminetetraacetic acid (EDTA) to an aqueous solution of tetraalkylammonium hydroxide to prevent metal impurities from adhering to the surface of the semiconductor substrate. . JP-A-3-219000 discloses chelating agents such as catechol and tyrone, JP-A-5-275405 discloses a complexing agent such as a phosphonic acid chelating agent or condensed phosphoric acid, and JP-A-6-163495 discloses a hydrazone derivative. The complexing agent is added to an alkaline cleaning solution such as [ammonia + hydrogen peroxide + water] to prevent metal impurities from adhering to the substrate. Propose to achieve.

However, when these complexing agents are added, a specific metal (for example, Fe) has an effect of preventing adhesion or removing, but a metal (for example, Al) which easily contaminates a processing solution or a substrate. Regarding (2), there is a problem that the effect of the complexing agent is extremely small, and a sufficient effect cannot be obtained even when a large amount of the complexing agent is added. In order to solve this problem, Japanese Patent Application Laid-Open No. Hei 6-216098 discloses that a substrate is washed with a [ammonia + hydrogen peroxide + water] washing solution to which a chelating agent such as a phosphonic acid chelating agent is added, and then a 1 ppm or more aqueous solution of hydrofluoric acid is used. However, in this method, 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. 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.

In order to solve the above problem, the present inventor has disclosed in Japanese Patent Application No. 8-56087 as ethylenediamine orthohydroxyphenylacetic acid [commonly known as:
EDDHA] and the like. This corresponds to the case where all of Y _{1 to} Y ₈ in the following general formula (1) of the present application are hydrogen atoms, but is disadvantageous in that the purification step is further required because the yield is low. As described above, in order to prevent metal impurity contamination from the surface treatment composition to the substrate surface, adhesion prevention has been attempted by adding various complexing agents. However, no sufficient improvement has been made yet, and the contamination prevention technology has been developed. It has not yet been achieved.

[0010]

DISCLOSURE OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is intended to prevent contamination of a substrate surface with metal impurities from a surface treatment composition and to provide a stable and extremely clean substrate surface. It is an object of the present invention to provide a substrate surface treatment composition which can achieve the above, and a substrate surface treatment method using the same.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, it has been found that a specific complexing agent is added and contained as a metal adhesion inhibitor in a surface treatment composition. The present inventors have found that the effect of preventing metal impurities from adhering to the substrate from the processing solution is remarkably improved, and arrived at the present invention.

That is, the gist of the present invention is to provide a surface treatment composition containing a complexing agent as a metal adhesion inhibitor in a liquid medium, wherein the complexing agent is an ethylenediaminephenol derivative represented by the following general formula (1) or surface treatment composition of the semiconductor substrate or a device substrate which is a salt thereof, and a semiconductor substrate or a device for groups using the same
It depends on the surface treatment method of the board .

[0013]

Embedded image

[0014] (wherein X _1, X ₂ is .Y ₁ ~ which represents a hydroxyl group
Y ₈ is each independently a hydrogen atom, a hydroxyl group, a halogen atom, a carboxyl group, a phosphonic acid group, a sulfonic acid group, a carbonyl group, a nitro group, a nitroso group, an amino group, an imino group, a nitrile group, a nitrile group, a thiocyanate group, Represents a hydroxyamino group, a hydroxyimino group, or an alkyl group or an alkoxy group which may have a substituent, and at least one of Y _{1 to} Y ₈ is not a hydrogen atom. Z _{1 to} Z ₄ each independently represent a hydrogen atom, a carboxyl group or a phosphonic acid group. R _{1 to} R ₄ each independently represent a hydrogen atom or an alkyl group which may have a substituent. )

In the case where the surface treatment is performed using the above-mentioned surface treatment composition, the optimum concentration of the complexing agent and other coexisting substances, and an effective method for supplying the lost treatment composition,
Also, a method for purifying an ethylenediaminephenol derivative or a salt thereof is included in the present invention.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
The surface treatment in the present invention is a general term for cleaning, etching, polishing, film formation and the like of a substrate, and the surface treatment composition is a general term for a surface treatment agent used for these purposes.

The surface treatment composition of the present invention is characterized in that it contains, as a metal adhesion inhibitor, one or more of the ethylenediaminephenol derivatives represented by the above general formula (1) or salts thereof. I do. In the general formula (1),
X ₁ and X ₂ represent a hydroxyl group. Y _{1 to} Y ₈ are each independently a hydrogen atom, a hydroxyl group, a halogen atom, a carboxyl group, a phosphonic acid group, a sulfonic acid group, a carbonyl group, a nitro group, a nitroso group, an amino group, an imino group, a nitrile group,
Nitrile group, thiocyanate group, hydroxyamino group,
It represents a hydroxyimino group, an alkyl group or an alkoxy group which may have a substituent, and at least one of Y _{1 to} Y ₈ is not a hydrogen atom. Z _{1 to} Z ₄ each independently represent a hydrogen atom, a carboxyl group, or a phosphonic acid group. R _{1 to} R ₄ each independently represent a hydrogen atom or an alkyl group which may have a substituent.

Specific examples of the above-mentioned optionally substituted alkyl or alkoxy group include a methyl group,
Ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, tert-butyl group, fluoromethyl group, chloromethyl group, bromomethyl group, trifluoromethyl group, 2-chloroethyl group, 2 A cyanoethyl group and the like, but are not limited thereto.

The hydroxyl group, phosphonic acid group, sulfonic acid group and carboxyl group may be separated from hydrogen cations to form anionic groups. Specific examples of such a complexing agent include the following, but are not particularly limited thereto. In addition, although specific examples are illustrated as acids, their corresponding salts such as ammonium salts and alkali metal salts are also included. In addition, the abbreviation or common name used in this specification is shown in [] after a compound name.

(1) Derivatives of ethylenediamine diorthohydroxyphenylacetic acid [EDDHA] (having a carboxyl group at the positions of Z ₁ and Z ₄ ) Ethylenediamine-N, N′-bis [(2-hydroxy-5-methylphenyl) ) Acetic acid] [EDDHMA], ethylenediamine-N, N'-bis [(2-hydroxy-5
-Chlorophenyl) acetic acid] [EDDHCA], ethylenediamine-N, N'-bis [(2-hydroxy-5-sulfophenyl) acetic acid] [EDDHSA], ethylenediamine-N, N'-bis [(2-hydroxy-5 -Phosphophenyl) acetic acid], ethylenediamine-N, N'-bis [(2-hydroxy-5-carboxyphenyl) acetic acid], ethylenediamine-N, N'-bis [(2-hydroxy-5-t-butylphenyl) Acetic acid], ethylenediamine-N, N'-bis [(2-hydroxy-3-methylphenyl) acetic acid], ethylenediamine-N, N'-bis [(2-hydroxy-4-methylphenyl) acetic acid],
Ethylenediamine-N, N'-bis [(2-hydroxy-3,5-dimethylphenyl) acetic acid], ethylenediamine-N, N'-bis [(2-hydroxy-4,6-dimethylphenyl) acetic acid] [EDDHDMA] , Ethylenediamine-N, N'-bis [(2-hydroxy-4,6-
Dichlorophenyl) acetic acid], 1,2-bis- (2-hydroxy-α-carboxybenzylamino) -propane,
1,2-bis- (2-hydroxy-α-carboxybenzylamino) -butane and the like.

(2) N, N'-bis (2-hydroxybenzyl) ethylenediamine-N, N'-diacetic acid [HBE
D] (having a carboxyl group at the position of Z ₂ or Z ₃ ) N, N′-bis (2-hydroxy-5-methylbenzyl) ethylenediamine-N, N′-diacetic acid [HMBE
D], N, N′-bis (2-hydroxy-5-chlorobenzyl) ethylenediamine-N, N′-diacetate,
N′-bis (2-hydroxy-5-sulfobenzyl) ethylenediamine-N, N′-diacetic acid, N, N′-bis (2-hydroxy-5-carboxybenzyl) ethylenediamine-N, N′-diacetic acid, N, N'-bis (2-hydroxy-3-methylbenzyl) ethylenediamine-
N, N'-diacetate, N, N'-bis (2-hydroxy-
4-methylbenzyl) ethylenediamine-N, N'-diacetate, N, N'-bis (2-hydroxy-3,5-dimethylbenzyl) ethylenediamine-N, N'-diacetic acid,
N, N'-bis (2-hydroxy-4,6-dimethylbenzyl) ethylenediamine-N, N'-diacetate,
N'-bis (2-hydroxy-4,6-dichlorobenzyl) ethylenediamine-N, N'-diacetic acid and the like.

(3) Others Ethylenediamine-N, N'-bis [(2-hydroxy-5-methylphenyl) phosphonic acid], ethylenediamine-N, N'-bis [(2-hydroxy-5-phosphophenyl) phosphone Acid] and the like. When choosing a complexing agent,
Judging comprehensively from the cleanliness level required for the substrate surface, the cost of the complexing agent, the chemical stability in the surface treatment composition to be added, etc., the choice is made. Although it cannot be said that there is ethylenediamine-N,
N'-bis [(2-hydroxy-5-methylphenyl)
Acetic acid] [EDDHMA], ethylenediamine-N, N '
-Bis [(2-hydroxy-5-chlorophenyl) acetic acid] [EDDHCA] and the like, and derivatives of ethylenediamine diorthohydroxyphenylacetic acid [EDDHA] (Z
₁ , those having a carboxyl group at the position of Z ₄ ) are excellent in both the metal adhesion preventing effect and the production cost, and are preferably used. Further, the ethylenediamine phenol derivative of the present invention is characterized in that, in the general formula (1), at least one or more of Y _{1 to} Y ₈ is substituted with an atom other than a hydrogen atom or a substituent. Ethylenediamine diorthohydroxyphenylacetic acid [EDDHA] in which all of Y _{1 to} Y ₈ are hydrogen atoms
In general, the substituted product of the present invention is superior in production cost and chemical stability as compared with the compound proposed in JP-A-56087.

Further, in addition to the above-mentioned specific complexing agent, a complexing agent as shown below is added to the surface treatment composition of the present invention,
Two or more kinds of complexing agents may be used in combination. In addition,
[] After the compound name is a common name or abbreviation of the compound.

Ethylenediamine, 8-quinolinol, o
Amines such as phenanthroline, amino acids such as glycine, iminodiacetic acid, nitrilotriacetic acid, ethylenediaminetetraacetic acid [EDTA], trans-1,2-diaminocyclohexanetetraacetic acid [CyDTA], diethylenetriaminepentaacetic acid [DTPA], triethylene Iminocarboxylic acids such as ethylenetetramine hexaacetic acid [TTHA], ethylenediaminetetrakis (methylenephosphonic acid) [EDTP
O], nitrilotris (methylene phosphonic acid) [NTP
O], iminophosphonic acids such as propylenediaminetetra (methylenephosphonic acid) [PDTMP], carboxylic acids such as formic acid, acetic acid, oxalic acid, and tartaric acid; and halogenation such as hydrofluoric acid, hydrochloric acid, hydrogen bromide, and hydrogen iodide. Hydrogen or a salt thereof, sulfuric acid, phosphoric acid, condensed phosphoric acid, boric acid,
Oxic acids such as silicic acid, carbonic acid, nitric acid, nitrous acid, perchloric acid, chloric acid, chlorous acid, hypochlorous acid, and salts thereof.

The amount of the complexing agent to be added as a metal adhesion inhibitor varies depending on the type and amount of metal impurities in the liquid to be prevented from adhesion and the level of cleanliness required on the substrate surface, and is therefore unconditionally determined. no but as the total amount of surface treatment composition, usually 10 ^-7 to 2%, preferably from 10
^Over 6 to 0.5% by weight, particularly preferably 10 ^-5 to 0.1 wt%. 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 serving as the main component in the surface treatment composition of the present invention is usually an aqueous solution in which water, electrolytic ionic water, an acid, an alkali, an oxidizing agent, a reducing agent, a surfactant and the like are dissolved.
Alternatively, 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. Further, in the surface treatment composition of the present invention, a solid such as abrasive grains may be added as an auxiliary component other than the liquid medium depending on the purpose of the surface treatment.

In the present invention, the alkaline aqueous solution is a general term for an aqueous solution whose pH is higher than 7. The alkaline component of this aqueous solution is not particularly limited, but a typical one is ammonia. Alkali metal or alkaline earth metal hydroxides such as sodium hydroxide, potassium hydroxide and calcium hydroxide; alkaline salts such as sodium hydrogencarbonate and ammonium hydrogencarbonate; and tetramethylammonium hydroxide (T
MAM), quaternary ammonium salt hydroxides such as trimethyl-2-hydroxyethylammonium hydroxide, choline and the like are also used. These alkalis are 2
Even if more than one kind is added, there is no problem at all, and it is usually used so that the total concentration in the whole solution of the surface treatment composition is 0.01 to 30% 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. When an oxidizing agent is used, the oxidizing agent concentration is preferably set to 1 wt ppm or more and 3 wt% or less. If the amount of the oxidizing agent is too large, the complexing agent is decomposed, and the stability of the surface treatment composition may be deteriorated. In particular, when hydrogen peroxide is used as the oxidizing agent, the concentration of hydrogen peroxide is preferably from 100 ppm by weight to 3% by weight.

The method for incorporating the complexing agent according to the present invention into 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. The complexing agent may be added in the form of an acid or in the form of a salt such as an ammonium salt.

In the case of SC-1 cleaning, the surface treatment is performed with a composition of ammonia + hydrogen peroxide + water + metal adhesion inhibitor. However, if the surface treatment composition is used for a long time,
As the ammonia evaporates, the metal adhesion inhibitor gradually decomposes, and the metal adhesion prevention effect deteriorates. Therefore, when replenishing the volatilized ammonia, it is preferable to replenish it with ammonia water containing a metal adhesion inhibitor. The concentration of ammonia in the aqueous ammonia solution to be replenished and the concentration of the complexing agent added as a metal adhesion inhibitor are:
It is determined by the volume ratio of evaporating ammonia, water and decomposing complexing agent. The amount of ammonia and water evaporated is determined by the initial ammonia concentration in the surface treatment composition, the temperature of the surface treatment, and the like. The amount of the complexing agent that decomposes is determined by the type and concentration of the complexing agent in the initial surface treatment composition and the conditions of the surface treatment. In general, when the surface treatment temperature is high, or when the surface treatment composition contains a high concentration of hydrogen peroxide, the decomposition of the complexing agent is promoted. The concentration of ammonia and the concentration of the complexing agent in the aqueous ammonia solution to be replenished are determined by these factors and cannot be unconditionally determined, but the ammonia concentration is usually 0.1 to 35% by weight, preferably 5 to 32% by weight. %, And the concentration of the complexing agent is 10 ^{-7 to} 5% by weight, preferably 10 ^-6 to 1% by weight. Further, the replenishing aqueous solution containing the complexing agent is
It is desirable that the content of metal impurities is usually ^10-4 % by weight or less for each metal. When the amount of metal impurities increases, a large amount of complexing agent is consumed to prevent the metal impurities from adhering, which is not economically preferable.

The surface treatment composition of the present invention is used for cleaning, etching, polishing, film formation, etc. of substrates such as semiconductors, metals, glasses, ceramics, plastics, magnetic materials, superconductors, etc., in which contamination of the substrate with metallic impurities becomes a problem. Used for surface treatment. 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 treatment composition of the present invention exerts a very good effect in preventing the adhesion of metal impurities is not yet clear, but the specific complexing agent to be added reacts with the metal ions, and This is presumed to form an extremely stable water-soluble metal complex.

When the surface treating 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, an appropriate one of the above-mentioned cleaning methods is adopted according to the purpose. Dip cleaning is suitable for cleaning a large number of substrates at once, but one cleaning takes a long time,
Spray cleaning and spin cleaning can reduce the number of substrates that can be cleaned at one time, but are characterized by a short cleaning time per cleaning. In the case of dip cleaning, the cleaning time is usually 30 seconds to 30 minutes, preferably 1 second.
~ 15 minutes, usually 1 second ~ 15 minutes, preferably 5 seconds ~ 5 in the case of spray cleaning or spin cleaning.
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.

In the present invention, a complexing agent may be a source of metal contamination when preparing a surface treatment composition. The complexing agent contains a metal reagent such as Fe in an amount of about several to several thousand ppm in a usual reagent. These initially exist in the form of a stable complex with the complexing agent.However, the complexing agent decomposes over a long period of use as a surface treatment solution, liberating the metal and releasing it on the substrate surface. It will adhere. for that reason,
It is desirable that the complexing agent used has a content of at least one metal element of Fe, Al, and Zn in the complexing agent of 5 ppm or less, in particular, an Fe content of 5 ppm or less,
It is desirable that the l content be 2 ppm or less and the Zn content be 2 ppm or less. In addition, F in the surface treatment composition
It is preferable that the content of e, Al, and Zn is 5 weight parts per billion or less. Such a complexing agent is obtained by dissolving the ethylenediamine phenol derivative of the present invention or a salt thereof in an acidic or alkaline solution, filtering and removing insoluble impurities, neutralizing again to precipitate a crystal, and subjecting the crystal to a liquid. And purified by separation. The filtration is preferably performed using a precision filtration filter having an opening of 0.5 μm or less.

[0034]

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 4 Aqueous ammonia (30% by weight), aqueous hydrogen peroxide (31% by weight) and water were mixed at a volume ratio of 1: 1: 10, and metal was added to the obtained aqueous solvent. A predetermined amount of the complexing agent shown in Table 1 was added as an antiadhesive agent to prepare a surface treatment composition. In addition,
The amount of the complexing agent added is represented by% by weight based on the aqueous solvent, and the name is represented by the above-mentioned common name. As a comparative example, a complexing agent described in JP-A-5-275405, ethylenediaminetetrakis (methylphosphonic acid) [commonly known as EDTPO] or [nitrilotris (methylphosphonic acid)] [commonly known as: NTPO], and a typical complexing agent ethylenediaminetetraacetic acid [E
DTA] and no complexing agent were added.

Al, F were added to the surface treatment solution thus prepared.
e was added as chlorides by 5 ppb each, and then a clean silicon wafer (p-type, CZ, plane orientation (100)) was immersed 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 immersion is overflow rinsed with ultrapure water for 10 minutes,
Al that was dried by nitrogen blow and adhered to the wafer surface,
Fe was quantified. Al, F attached on silicon wafer
e was recovered with a mixed solution of hydrofluoric acid 0.1% by weight and hydrogen peroxide 1% by weight, and the amount of the metal was measured by a flameless atomic absorption method and converted into a substrate surface concentration (atoms / cm ² ). The results are shown in Table 1.

[0036]

[Table 1]

Examples 6 to 8 and Comparative Examples 5 to 9 were obtained by mixing aqueous ammonia (30% by weight), aqueous hydrogen peroxide (31% by weight) and water in a volume ratio of 1: 1: 10. Using the mixed solution as the main component of the aqueous solvent, the aqueous solvent,
As the metal adhesion inhibitor, the specific 2 of the present invention described in Table 1
Predetermined amounts of various complexing agents were added to prepare the surface treatment composition of the present invention. In addition, for comparison, the aqueous solvent
A complexing agent to which one kind of complexing agent is added among the complexing agents used in Examples, a complexing agent to which EDTPO [ethylenediaminetetrakis (methylphosphonic acid)] described in JP-A-5-275405 is added, Also, one without any complexing agent was prepared. However, Comparative Example 5 is a repost of Comparative Example 1, Comparative Example 6 is a repost of Example 1, Comparative Example 8 is a repost of Example 2, and Comparative Example 9 is a repost of Example 2. It is posted.

After adding 5 ppb each of Al and Fe as chlorides to the surface treatment solution thus prepared, a clean silicon wafer (p-type, CZ, plane orientation (100))
For 10 minutes. 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 overflow-rinsed with ultrapure water for 10 minutes, then dried by nitrogen blowing, and A
l and Fe were quantified. A adhered on silicon wafer
l and Fe are 0.1% by weight of hydrofluoric acid and 1% by weight of hydrogen peroxide
And the amount of the metal was measured by flameless atomic absorption spectrometry, and converted to the substrate surface concentration (atoms / cm ² ). Table 2 shows the results.

[0039]

[Table 2]

[0040]

The surface treatment composition of the present invention contains a specific complexing agent as a metal adhesion inhibitor, thereby preventing contamination of metal impurities such as Al and Fe from the surface treatment composition onto the substrate surface. An extremely clean substrate surface can be stably achieved. In particular, when the present invention is applied to alkali cleaning of a semiconductor substrate typified by [ammonia + hydrogen peroxide + water] cleaning and the like, the problem of metal impurity attachment to the substrate, which was a problem of the cleaning method, is improved. Thereby, by the washing,
A highly clean substrate surface free of metal contamination as well as particles and organic contamination is achieved. For this reason, acid cleaning such as [hydrochloric acid + hydrogen peroxide + water] cleaning, which has been conventionally used after the cleaning, can be omitted, and the cleaning cost and the cost of a clean room such as exhaust equipment can be significantly reduced. To become
This is a great advantage for industrial production of semiconductor integrated circuits.

In the production of semiconductors, liquid crystals, etc., the wet process such as etching and cleaning is performed with a metal impurity concentration of 0.1 ppb in order to prevent metal impurities from adhering to the substrate surface.
The following ultrapure water and ultrahigh-purity chemicals are used. Furthermore, these chemicals need to be replaced frequently because metal impurities are mixed during use. However, according to the present invention, adhesion can be prevented even if a large amount of metal impurities are present in the solution, so that it is not necessary to use an ultra-high purity chemical solution, and the chemical solution is contaminated with metal impurities during use. Even if it is done, it is not necessary to replace it frequently, so that the cost of chemicals and their management can be greatly reduced.

In addition, 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 in the liquid as an impurity, it will electrochemically adhere to the substrate surface. According to the present invention, the metal impurities become stable water-soluble metal complexes, which can be prevented. Further, if the present invention is applied to an abrasive slurry for polishing a substrate, it is possible to prevent metal impurities present in a large amount in the abrasive slurry and concentrated in the slurry together with polishing of the substrate from adhering to the substrate. As described above, the ripple effect of the surface treatment agent of the present invention is enormous, and it is industrially very useful.

Continued on the front page (58) Fields investigated (Int. Cl. ⁷ , DB name) C11D 7/32 C09K 3/00 C09K 13/06 H01L 21/304 CA (STN) CAOLD (STN) REGISTRY (STN)

Claims (11)

(57) [Claims] 1. A surface treatment composition containing a complexing agent as a metal adhesion inhibitor in a liquid medium, wherein the complexing agent is an ethylenediaminephenol derivative represented by the following general formula (1) or a salt thereof. A composition for surface treatment of a semiconductor substrate or a substrate for a device, comprising: Embedded image (Wherein X ₁ and X ₂ represent a hydroxyl group. Y ₁ to Y ₈ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a carboxyl group, a phosphonic acid group, a sulfonic acid group, a carbonyl group,
A nitro group, a nitroso group, an amino group, an imino group, nitrilo group, a nitrile group, a thiocyanate group, a hydroxyamino group, hydroxyimino group, or represents an alkyl group or alkoxy group which may have a substituent, Y ₁ ~
At least one of Y ₈ is not a hydrogen atom. Z ₁
To Z ₄ each independently represent a hydrogen atom, a carboxyl group or a phosphonic acid group. R _{1 to} R ₄ each independently represent a hydrogen atom or an alkyl group which may have a substituent. ) 2. The concentration of the complexing agent in the surface treatment composition is 10%.
^The composition for surface treatment of a semiconductor substrate or a device substrate according to claim 1, wherein the composition is ^{-7 to} 5% by weight. 3. The composition for surface treatment of a semiconductor substrate or a device substrate according to claim 1, wherein the liquid medium is an alkaline aqueous solution. 4. The composition for surface treatment of a semiconductor substrate or a device substrate according to claim 1, wherein the liquid medium is an alkaline aqueous solution containing ammonia and hydrogen peroxide. 5. The composition for surface treating a semiconductor substrate or a device substrate according to claim 1, wherein the liquid medium contains 1% by weight or more and 3% by weight or less of an oxidizing agent. 6. The composition for surface treatment of a semiconductor or device substrate according to claim 1, wherein the composition for surface treatment is a composition for etching, polishing or cleaning the surface of a semiconductor substrate or a device substrate. Composition. 7. A surface treatment method for a semiconductor substrate or a device substrate, wherein the surface treatment is performed using the composition for surface treatment according to claim 1. 8. The surface of a substrate using, in a liquid medium, a surface treatment composition containing ammonia, water, and an ethylenediaminephenol derivative represented by the general formula (1) or a salt thereof as a metal adhesion inhibitor. A surface treatment method for a semiconductor substrate or a device substrate, wherein the evaporated ammonia is supplemented with an aqueous ammonia solution containing the complexing agent during the treatment. 9. The surface treatment method for a semiconductor substrate or device substrate according to claim 7, wherein the liquid medium further contains hydrogen peroxide. Method. 10. The method for treating a surface of a semiconductor substrate or a device substrate according to claim 7, wherein the ammonia water to be replenished has an ammonia concentration of 0.1 to 35% by weight and a complex represented by the general formula (1). A surface treatment method for a semiconductor substrate or a device substrate, wherein an agent concentration is 10 ^{-7 to} 5% by weight and a metal impurity concentration is 10 ^-4 % by weight or less for each metal. 11. The composition for surface treatment of a semiconductor or device substrate according to claim 1, wherein the surface treatment is a composition for etching, polishing or cleaning the surface.