JP2012186470A - Cleaner for copper wiring semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cleaner for a copper/copper alloy wiring semiconductor in which organic residue does not corrode a copper wiring even in the case where benzotriazol is a rust inhibitor of high HLB containing functional group such as carboxyl group and hydroxyl group as well as in the case where the benzotriazol is a rust inhibitor, being excellent in organic residue removability and metal residue removability.SOLUTION: The cleaner for a copper wiring semiconductor is characterized by containing, as essential components, one or more kinds of amine (A) selected from a group including amine (A1) containing at least one hydroxy group and aliphatic polyamine (A2) having a specific chemical structure, polyphenol compound (B) which contains two to five hydroxyl groups and at least two of them are combined to ortho position or para position of aromatic ring, with HLB being 15-40, basic compound (C), and water, with pH in use being 8.0-13.0.

Description

The present invention relates to a cleaning agent (hereinafter referred to as a post-CMP cleaning agent) used in a cleaning step after a chemical mechanical polishing (hereinafter, “chemical mechanical polishing” is abbreviated as CMP) step in a semiconductor manufacturing process. And a post-CMP cleaning agent for a semiconductor having a copper or copper alloy wiring on its surface.

Semiconductor elements typified by silicon semiconductors have been miniaturized and highly integrated in response to market needs such as higher performance and smaller size. Along with this, an advanced planarization technique for creating a fine wiring pattern is indispensable, and a polishing slurry (hereinafter abbreviated as CMP slurry) containing fine particles of alumina or silica on the wafer surface in a semiconductor manufacturing process. A CMP process that uses and polishes is introduced.

However, in this CMP process, abrasive fine particles such as alumina and silica in the CMP slurry (hereinafter, “abrasive fine particles” are abbreviated as abrasive grains), an iron nitrate aqueous solution added to promote polishing, and metal corrosion suppression purposes. The anticorrosive agent added in step 1 and the polished metal polishing residue are likely to remain on the polished wafer. Since these residues adversely affect the electrical characteristics of the semiconductor, such as a short circuit between wirings, it is necessary to remove these residues and clean the wafer surface.

  As a cleaning agent used in the cleaning step after the CMP step, a cleaning agent containing a cyclic amine having a specific chemical structure and a polyphenol compound containing 2 to 5 hydroxyl groups (Patent Document 1), a specific cleaning agent, a chelating agent, A cleaning composition comprising a corrosion inhibitor (Patent Document 2) is known.

However, in Patent Documents 1 and 2, it is necessary to remove metal residues from the residues on the wafer and benzotriazole-derived organic residues (such as insoluble complexes formed from benzotriazole and copper ions) as a rust inhibitor. Although effective, organic residues derived from rust inhibitors with high HLB, such as quinaldic acid having a carboxyl group and hydroxybenzotriazole having a hydroxyl group, may not be compatible with metal residue removal. .

JP 2010-235725 A Special table 2007-525836 gazette

Therefore, the present invention is not limited to the case where the organic residue is benzotriazole as a rust preventive agent, but also in the case of a complex of copper ions with a high HLB rust preventive agent having a functional group such as a carboxyl group or a hydroxyl group. An object of the present invention is to provide a cleaning agent for copper and copper alloy wiring semiconductors that is excellent in metal residue removability and organic residue removability without causing corrosion.

The inventors of the present invention have reached the present invention as a result of studies to achieve the above object.
That is, the present invention provides one or more amines (A) selected from the group consisting of an amine (A1) having one or more hydroxyl groups and an aliphatic polyamine (A2) represented by the following general formula having a specific chemical structure. A polyphenol compound (B) having 2 to 5 hydroxyl groups, at least two of which are bonded to the ortho or para position of the aromatic ring, and having an HLB of 15 to 40, a basic compound (C) and a cleaning agent for copper wiring semiconductors, wherein water is an essential component and the pH during use is 8.0 to 13.0; and a semiconductor manufacturing process for forming copper or copper alloy wirings A semiconductor substrate or a semiconductor element manufactured by using this cleaning agent in a process subsequent to chemical mechanical polishing.

The cleaning agent for copper wiring semiconductor of the present invention is excellent not only in organic residues derived from benzotriazole, but also in organic residue derived from rust preventives having high carboxyl group and hydroxyl group, and in metal residue removability. Excellent.
In addition, by using the cleaning agent of the present invention in a process after the CMP process in the semiconductor manufacturing process, a semiconductor substrate or a semiconductor element having excellent contact resistance and no wiring short-circuit can be easily obtained.

The cleaning agent for a copper wiring semiconductor of the present invention has an amine (A) having a specific chemical structure and 2 to 5 hydroxyl groups, and at least two of these hydroxyl groups are ortho positions or para groups of the aromatic ring. A polyphenol compound (B), a basic compound (C), and water, which are bonded to the position, are essential components, and the pH during use is 8.0 to 13.0.
Furthermore, the amine (A) of the present invention is an amine (A1) having one or more hydroxyl groups and / or an aliphatic polyamine (A2) represented by a specific general formula, and the HLB of the polyphenol compound (B) of the present invention. Is also a requirement of 15-40.

In the amine (A) as the first essential component of the present invention, the amine (A1) having at least one hydroxyl group includes an aliphatic amine (A11) having at least one hydroxyl group and an alicyclic amine having at least one hydroxyl group. (A12), aralkylamine (A13) having one or more hydroxyl groups, and heterocyclic amine (A14) having one or more hydroxyl groups.

Examples of the aliphatic amine (A11) having one or more hydroxyl groups include aliphatic amines (A111) having one or more hydroxyl groups and no tertiary amino group, and fatty acids having one or more hydroxyl groups and a tertiary amino group. Group amine (A112).

Examples of the aliphatic amine (A111) having at least one hydroxyl group and no tertiary amino group include monoethanolamine, diethanolamine, 2-amino-2-methyl-1-propanol, N- (aminoethyl) ethanolamine and the like. Is mentioned.
Examples of the aliphatic amine (A112) having at least one hydroxyl group and a tertiary amino group include triethanolamine, dimethylaminoethanol, diethylaminoethanol, N, N-dimethyl-2-aminoethanol, and triethylenetetramine hydroxyalkyl. Substituents and the like can be mentioned.
A monoamine or polyamine may be used as long as it contains at least one hydroxyl group.

Examples of the alicyclic amine (A12) having one or more hydroxyl groups include 1,3- and 1,4-diaminocyclohexane, isophorone diamine, menthane diamine, and 4,4′-methylene dicyclohexane diamine (hydrogenated methylene dianiline). And the like, and the like.

Examples of the aralkylamine (A13) having one or more hydroxyl groups include araliphatic amines such as metaxylylenediamine and hydroxyalkyl substituents such as aminoethylbenzene.

Examples of the heterocyclic amine (A14) having one or more hydroxyl groups include hydroxyalkyl substituents such as piperazine, N-aminoethylpiperazine, and 1,4-diaminoethylpiperazine.

The amine (A1) having one or more hydroxyl groups is preferably an aliphatic amine (A11) having one or more hydroxyl groups, more preferably a hydroxyalkyl-substituted product of triethanolamine or triethylenetetramine.

Another amine that can be used in the first essential component amine (A) of the present invention is an aliphatic polyamine (A2) that is represented by the following general formula (1) and does not contain a hydroxyl group.

[In Formula (1), m is an integer of 0-10, n is an integer of 1-10. R ^{1 to} R ⁵ each independently represents a hydrogen atom or an alkyl group, but at least one of (m + 2) nitrogen atoms is a tertiary amino group. ]

Specific examples of the aliphatic polyamine (A2) represented by the general formula (1) include tetramethylethylenediamine, pentamethyldiethylenetriamine, 1,1-dimethyldiethylenetriamine, hexamethyltriethylenetetramine, and the like.

Among the aliphatic polyamines (A2), from the viewpoint of removal of abrasive grains remaining on the wafer after the CMP step, the amine represented by the above general formula (1), all nitrogen atoms being tertiary amino acids The aliphatic polyamine (A21) as a group is preferred. More preferred are pentamethyldiethylenetriamine, tetramethylethylenediamine, and hexamethyltriethylenetetramine.

Among these amines (A), the aliphatic amine (A11) having one or more hydroxyl groups is preferable from the viewpoint of copper wiring corrosion resistance and removability of organic residues remaining on the wafer after the CMP process. It is an aliphatic polyamine (A2) represented by the general formula.

In addition to the amine (A1) having at least one hydroxyl group as an essential component and / or the aliphatic polyamine (A2) represented by the general formula (1), the cleaning agent of the present invention may contain other amines. Good.
For example, quinaldic acid removability can be improved by using a heterocyclic polyamine in combination.

The content of amine (A) is based on the total weight when amine (A), polyphenol compound (B), basic compound (C), and water are used, from the viewpoint of copper wiring corrosion resistance and organic residue removal. Based on this, it is usually 0.001 to 10% by weight, preferably 0.005 to 5% by weight, more preferably 0.01 to 2% by weight, and particularly preferably 0.01 to 1% by weight.

The polyphenol compound (B), which is the second essential component of the cleaning agent for copper wiring semiconductor of the present invention, has 2 to 5 hydroxyl groups bonded to an aromatic ring or the like, and at least 2 of these hydroxyl groups are aromatic. Among compounds containing a phenol skeleton bonded to the ortho or para position of the ring, those having an HLB of 15 to 40. It should be noted that other functional groups such as a hydrocarbon group and a carboxyl group may be bonded to the aromatic ring.

Specifically, examples of the polyphenol compound (B1) containing two hydroxyl groups include catechol (HLB = 17.9), caffeic acid (HLB = 20.5), hydroquinone (HLB = 17.9) and the like.
Examples of the polyphenol compound (B2) containing three hydroxyl groups include pyrogallol (HLB = 26.3), gallic acid (HLB = 33.2), gallic amide (HLB = 36.8), and propyl gallate (HLB = 18). .8) and the like.
Examples of the polyphenol compound (B3) having 4 or 5 hydroxyl groups include quercetin (HLB = 23.7), catechin (HLB = 21.2) and the like.

Here, “HLB” is an index indicating a balance between hydrophilicity and lipophilicity, and is described in, for example, “Introduction to Surfactants” (published by Sanyo Chemical Industries, Ltd., 2007, Takehiko Fujimoto), page 212. It is known as the calculated value by the Oda method, not the calculated value by the Griffin method.
The HLB value can be calculated from the ratio between the organic value and the inorganic value of the organic compound.
The organic value and the inorganic value for deriving HLB≈10 × inorganic / organic HLB can be calculated using the values in the table described in “Introduction of Surfactant” on page 213.

Of these polyphenol compounds (B), from the viewpoint of copper wiring corrosion resistance, polyphenol compounds (B2) containing 3 hydroxyl groups and polyphenol compounds (B3) containing 4 or 5 hydroxyl groups are preferred. Further, from the viewpoint of chemical stability with time in the cleaning agent, the polyphenol compound (B2) containing three hydroxyl groups having an HLB of 17 to 38 is more preferable. Moreover, the gallic acid which has a carboxyl group from a viewpoint of metal residue removability is especially preferable.

The content of the polyphenol compound (B) in the present invention is determined from the viewpoints of copper wiring corrosion resistance and metal residue removability when amine (A), polyphenol compound (B), basic compound (C), and water are used. Is usually 0.001 to 5% by weight, preferably 0.001 to 2% by weight, more preferably 0.005 to 1% by weight, and particularly preferably 0.01 to 0.3% by weight. %.

Examples of the basic compound (C) that is the third essential component of the cleaning agent for copper wiring semiconductors of the present invention include quaternary ammonium hydroxide (C1) and ammonia (C2).
The quaternary ammonium hydroxide (C1) includes an alkyl group, an alkenyl group, an allyl group, an aralkyl group, or a cation in which a hydrocarbon group in which one part thereof is substituted with a hydroxy group is bonded to a quaternary nitrogen atom. Examples thereof include salts composed of anions.

Of the quaternary ammonium hydroxides (C1), quaternary ammonium hydroxides (C11) represented by the following general formula (2) are preferable.

[R < ⁶ > -R < ⁹ > in Formula (2) represents a C1-C4 alkyl group or a hydroxyalkyl group each independently. ]

Specifically, tetraalkylammonium salts having 1 to 4 carbon atoms or hydroxyalkyl groups, trialkyl-hydroxyalkylammonium salts, dialkyl-bis (hydroxyalkyl) ammonium salts and tris (hydroxyalkyl) alkylammonium salts Etc.

Of these quaternary ammonium hydroxides (C1), tetraalkylammonium hydroxide, (hydroxyalkyl) trialkylammonium hydroxide, bis (hydroxyalkyl) dialkylammonium hydroxide and tris ( Hydroxyalkyl) alkylammonium hydroxide is preferred.
Further, from the viewpoint of copper wiring corrosion resistance, tetraalkylammonium hydroxide and (hydroxyalkyl) trialkylammonium hydroxide are preferable.
Tetramethylammonium hydroxide, tetraethylammonium hydroxide, and (hydroxyethyl) trimethylammonium hydroxide (choline) are more preferable, and tetramethylammonium hydroxide is particularly preferable.

The content of the basic compound (C) is the sum of the amine (A), polyphenol compound (B), basic compound (C), and water in use from the viewpoint of organic residue removal and copper wiring corrosion resistance. Based on the weight, it is usually 0.01 to 10% by weight, preferably 0.02 to 5% by weight, and more preferably 0.03 to 2% by weight.

The cleaning agent for a copper wiring semiconductor of the present invention contains water as an essential component, and specifically includes those having a low electrical conductivity (μS / cm; 25 ° C.). Specifically, the electrical conductivity is usually from the viewpoint of removability of organic residues and metal residues, availability, and prevention of re-contamination of copper wiring (re-adhesion of metal ions in water to copper wiring). 0.055-0.2 μS / cm, preferably 0.056-0.1 μS / cm, more preferably 0.057-0.08 μS / cm. As such water with low electrical conductivity, ultrapure water is preferable.
In addition, electrical conductivity is measured based on JIS K0400-13-10: 1999.

The copper wiring semiconductor cleaning agent is an essential component amine (A), polyphenol compound (B), basic compound (C), for the purpose of improving the oxidation-inhibiting function and metal residue removability for the polyphenol compound (B), By using ascorbic acid (D) in addition to water, both copper wiring corrosion resistance and metal residue removability can be satisfied.
Specific examples of ascorbic acid (D) include L-ascorbic acid and isoascorbic acid (erythorbic acid).

About content of ascorbic acid (D), it is preferable to satisfy | fill the following relational expression (1) from a viewpoint of metal residue removal property, and also it is preferable to satisfy | fill relational expression (2).

0.7 ≦ {[B] + [D]} / [C] ≦ 1.3 (1)

0.9 ≦ {[B] + [D]} / [C] ≦ 1.2 (2)

In formulas (1) and (2), [B], [C], and [D] are the moles of the components of polyphenol compound (B), basic compound (C), and ascorbic acid (D), respectively. Represents concentration (mol / L).

The content of ascorbic acid (D) is based on the total weight when using amine (A), polyphenol compound (B), basic compound (C), ascorbic acid (D) and water from the viewpoint of metal residue removability. Based on this, it is usually 0.01 to 5% by weight, preferably 0.05 to 3% by weight, more preferably 0.1 to 2% by weight, and particularly preferably 0.1 to 1% by weight.

  The cleaning agent of the present invention has a pH during use of usually 8.0 to 13.0, preferably 9.0 to 13.0, from the viewpoints of copper wiring corrosion resistance and metal residue removal. More preferably, it is 9.5 to 12.0. If the pH during use of the cleaning agent is less than 8.0 or exceeds 13.0, copper is easily ionized and the copper wiring corrosion resistance deteriorates.

The cleaning agent for copper wiring semiconductor of the present invention contains an essential component amine (A), polyphenol compound (B), basic compound (C), water, and ascorbic acid (D) to be added as necessary. However, the surfactant (E1), a reducing agent (E2) other than the polyphenol compound (B) containing 2 to 5 hydroxyl groups, and a complexing agent (E3) are within the range not impairing the performance of the cleaning agent for semiconductors of the present invention. ), A corrosion inhibitor (E4) or the like may be added.

Surfactant (E1) can be added from the viewpoint of improving organic residue removability and metal impurity removability.
Examples of such surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants.
In the case of adding a surfactant, the content of the surfactant may be an amount necessary for reducing the surface tension of the cleaning agent, and is usually 0.00 on the basis of the weight of the cleaning agent for copper wiring semiconductor of the present invention. It is 001 to 1% by weight, preferably 0.005 to 0.3% by weight, particularly preferably 0.01 to 0.1% by weight.

Examples of the reducing agent (E2) other than the polyphenol compound (B) include an organic reducing agent and an inorganic reducing agent.
Examples of the organic reducing agent include oxalic acid or salts thereof, aldehydes having 6 to 9 carbon atoms, phenolic compounds containing one hydroxyl group, benzaldehyde, and the like, and inorganic reducing agents include sulfurous acid or a salt thereof, thiosulfuric acid or a salt thereof. Examples include salts.

Among these reducing agents (E2), from the viewpoint of water solubility and copper wiring corrosion resistance, an organic reducing agent is preferable, an aliphatic organic reducing agent is more preferable, and oxalic acid or a salt thereof is particularly preferable. Furthermore, from the viewpoint of complexing action, oxalate is preferable, and ammonium oxalate is more preferable.

When these reducing agents are added, the content of the reducing agent (E2) is usually 0.001 to 0.001 based on the weight of the cleaning agent for copper wiring semiconductors of the present invention from the viewpoint of improving the corrosion resistance of the copper wiring. The amount is 1.0% by weight, more preferably 0.01 to 0.5% by weight, and particularly preferably 0.05 to 0.1% by weight. If the content of these reducing agents, that is, reducing agents other than polyphenols containing 2 to 5 hydroxyl groups, exceeds 1.0% by weight, the copper wiring corrosion resistance is adversely reduced.

Examples of the complexing agent (E3) include aromatic or aliphatic hydroxycarboxylic acids (or salts thereof), heterocyclic compounds having at least one of a hydroxyl group or a carboxyl group, and phosphonic acids (or salts thereof).

Among these complexing agents (E3), aliphatic hydroxycarboxylic acid (or a salt thereof) and polycarboxylic acid (or a salt thereof) are preferable from the viewpoint of improving copper wiring corrosivity, and an aliphatic hydroxycarboxylic acid (or a salt thereof). Salt) is particularly preferred.

When adding the complexing agent, the content of the complexing agent (E3) is usually 0.001 to 0 based on the weight of the cleaning agent for copper wiring semiconductor of the present invention from the viewpoint of improving the corrosion resistance of the copper wiring. 0.5 wt%, preferably 0.01 to 0.3 wt%, particularly preferably 0.05 to 0.1 wt%. When the content of the complexing agent (E3) is more than 0.5% by weight, the copper wiring corrosion resistance is reduced.

Examples of the corrosion inhibitor (E4) include nitrogen atom-containing heterocycle-containing compounds (purine derivatives, imidazole derivatives, pyrazole derivatives, thiazole derivatives, quinoline derivatives, quinoxaline derivatives, and the like).

Of these corrosion inhibitors (E4), purine derivatives are preferred, and adenine and adenosine are particularly preferred from the viewpoint of improving copper wiring corrosivity.

When the corrosion inhibitor is added, the content of the corrosion inhibitor (E4) is usually 0.00001 to 1 based on the weight of the copper wiring semiconductor cleaning agent of the present invention from the viewpoint of improving the copper wiring corrosion resistance. % By weight, preferably 0.00003 to 0.5% by weight, more preferably 0.00005 to 0.1% by weight, particularly preferably 0.0001 to 0.01% by weight. When the content of the corrosion inhibitor (E4) is more than 0.5% by weight, the copper wiring corrosion resistance is reduced.

The cleaning agent for a copper wiring semiconductor of the present invention is produced by mixing amine (A), polyphenol compound (B), basic compound (C), ascorbic acid (D), and other components as necessary with water. be able to.
The mixing method is not particularly limited, but from the viewpoint of easy and uniform mixing in a short time, water, amine (A) and basic compound (C) are mixed, followed by polyphenol compound (B), A method of mixing other components as required is preferable.
There is no restriction | limiting in temperature and time at the time of uniform mixing, According to the scale to manufacture, an installation, etc., it can determine suitably.
As the mixing device, a stirrer or a disperser can be used. Examples of the stirrer include a mechanical stirrer and a magnetic stirrer. Examples of the disperser include a homogenizer, an ultrasonic disperser, a ball mill, and a bead mill.

The cleaning agent for a copper wiring semiconductor of the present invention can be used in a cleaning method for cleaning a semiconductor substrate having a copper wiring, a semiconductor element, a copper plating substrate for semiconductor cleaning property evaluation, and the like.

As a cleaning method for cleaning a semiconductor substrate or a semiconductor element having a copper wiring, a single wafer method and a batch method can be given. The single wafer method is a method in which a semiconductor substrate or a semiconductor element is rotated one by one, and a cleaning is performed using a brush while injecting a cleaning agent for a copper wiring semiconductor. The batch method is a plurality of semiconductor substrates or semiconductor elements. Is cleaned by immersing it in a cleaning agent for copper wiring semiconductors.

The copper wiring semiconductor cleaning agent of the present invention is a process for producing a semiconductor substrate or a semiconductor element having copper wiring, after resist development, after dry etching, after wet etching, after dry ashing, after resist stripping, before and after CMP treatment, and It can be used for cleaning processes before and after CVD processing. In particular, from the viewpoint of organic residue removability and metal impurity removability, it is preferably used in the cleaning step after CMP treatment.

  Hereinafter, although an example and a comparative example explain the present invention further, the present invention is not limited to these. Hereinafter, unless otherwise specified, “%” represents “% by weight” and “parts” represents “parts by weight”.

Examples 1-8 and Comparative Examples 1-7
The composition shown in Table 1 was carried out in a polyethylene container to obtain a cleaning agent for copper wiring semiconductor of the present invention and a cleaning agent for comparison.

About the cleaning agent for copper wiring semiconductors of the present invention and the cleaning agent for copper wiring semiconductors for comparison, the following methods are used to remove organic residues as benzotriazole residues, quinaldic acid residues, and metal residues. Was measured and evaluated.
The evaluation results are shown in Table 1.

<Method for evaluating benzotriazole residue removability>
Evaluation of benzotriazole residue removability was performed according to the following procedure.
(1) Cleaning of copper-plated silicon wafer A wafer obtained by subjecting a silicon wafer to copper plating (manufactured by Advanced Material Technology, “Cu plating 10000A Wafer”, copper plating film thickness = 1.0 μm) The sample was cut into 5 cm × 1.5 cm, immersed in a 10% aqueous acetic acid solution for 1 minute, and then washed with ultrapure water.

(2) Preparation of benzotriazole residue liquid 0.4 g of benzotriazole, 0.6 g of 30% hydrogen peroxide water, and 200 g of ultrapure water were mixed and adjusted to pH 3.0 with hydrochloric acid. A triazole residue was prepared.

(3) Preparation of copper-plated wafer to which benzotriazole residue was adhered A copper-plated wafer was immersed in the benzotriazole residue liquid prepared in (2) for 60 seconds, and then immersed in ultrapure water for 60 seconds to attach the benzotriazole residue. A copper plated wafer was prepared.

(4) Measurement of the amount of benzotriazole residue adhered to a copper-plated wafer The amount of nitrogen derived from benzotriazole, which is a benzotriazole residue, was measured using an X-ray photoelectron spectroscopy (XPS) apparatus (manufactured by ULVAC-PHI, ESCA-5400 type). The amount of benzotriazole residue adhering to the copper-plated wafer was measured by measuring using.
Specifically, using XPS, the number of photoelectrons was measured within a binding energy range of 397 eV to 399 eV, and a peak area value within a range of 397.5 to 398.4 eV derived from nitrogen was determined. As the soft X-ray, MgKα ray (1253.6 eV) was used.

(5) Removal of benzotriazole residue adhered to copper-plated wafer The copper-plated wafer with the benzotriazole residue prepared in (3) was immersed in 50 g of the cleaning agent for copper wiring semiconductor of the present invention and comparative for 3 minutes. The benzotriazole residue was removed from the copper plated wafer. Thereafter, the wafer surface was immersed in 1 L of ultrapure water for 60 seconds, and the wafer surface was dried with a nitrogen stream.

(6) Measurement of the amount of benzotriazole residue remaining on the copper-plated wafer The amount of nitrogen derived from benzotriazole, which is an organic residue, was measured using XPS in the same manner as in (4), thereby remaining benzotriazole on the copper-plated wafer. The amount of triazole residue was measured.

(7) Evaluation and determination of benzotriazole residue removability The respective peak area values measured by XPS in (4) and (6) were substituted into the following formula (1) to calculate the benzotriazole residue removal rate.

Xa: Peak area value of nitrogen derived from benzotriazole before removal of benzotriazole residue Xb: Peak area value of nitrogen derived from benzotriazole after removal of benzotriazole residue

From the calculated benzotriazole residue removal rate, benzotriazole residue removability was determined according to the following criteria.
A: Benzotriazole residue removal rate is 95% or more B: Benzotriazole residue removal rate is 85-95%
Δ: Benzotriazole residue removal rate is 75 to 85%
X: Benzotriazole residue removal rate is less than 75%

<Evaluation method of quinaldic acid residue removal property>
Evaluation of quinaldic acid residue removal property was performed according to the following procedure.
(1) Cleaning of copper-plated silicon wafer A wafer obtained by subjecting a silicon wafer to copper plating (manufactured by Advanced Material Technology, “Cu plating 10000A Wafer”, copper plating film thickness = 1.0 μm) The sample was cut into 5 cm × 1.5 cm, immersed in a 10% aqueous acetic acid solution for 1 minute, and then washed with ultrapure water.

(2) Preparation of quinaldic acid residue liquid 0.4 g of quinaldic acid, 0.6 g of 30% hydrogen peroxide solution, and 200 g of ultrapure water were mixed and adjusted to a pH of 3.0 with hydrochloric acid. An acid residue solution was created.

(3) Preparation of copper-plated wafer to which quinaldic acid residue was adhered After immersing the copper-plated wafer in the quinaldic acid residue liquid prepared in (2) for 60 seconds, the copper-plated wafer was immersed in ultrapure water for 60 seconds to allow the quinaldic acid residue to adhere. A copper plated wafer was prepared.

(4) Measurement of the amount of quinaldic acid residue adhered to the copper-plated wafer The amount of nitrogen derived from quinaldic acid, which is a quinaldic acid residue, is measured in terms of the number of photoelectrons within the range of binding energy of 397 eV to 399 eV using the above X-ray photoelectron spectroscopy. Was measured to measure the amount of quinaldic acid residue adhering to the copper-plated wafer.

(5) Removal of quinaldic acid residue adhering to copper-plated wafer The copper-plated wafer having the quinaldic acid residue prepared in (3) adhered to 50 g each of the present invention and a comparative copper wiring semiconductor cleaning agent was immersed for 3 minutes. The quinaldic acid residue was removed from the copper plated wafer. Thereafter, the wafer surface was immersed in 1 L of ultrapure water for 60 seconds, and the wafer surface was dried with a nitrogen stream.

(6) Measurement of the amount of quinaldic acid residue remaining on the copper-plated wafer The amount of nitrogen derived from quinaldic acid, which is an organic residue, was measured using XPS, as in (4), to leave the quinaldine remaining on the copper-plated wafer. The amount of acid residue was measured.

(7) Evaluation determination of quinaldic acid residue removal property Each peak area value measured by XPS in (4) and (6) was substituted into the following mathematical formula (2) to calculate the quinaldic acid residue removal rate.

Ya: Peak area value of nitrogen derived from quinaldic acid before removal of quinaldic acid residue Yb: Peak area value of nitrogen derived from quinaldic acid after removal of quinaldic acid residue

From the calculated removal rate of quinaldic acid residue, quinaldic acid residue removability was determined according to the following criteria.
A: The quinaldic acid residue removal rate is 95% or more. B: The quinaldic acid residue removal rate is 85-95%.
Δ: 75% to 85% removal rate of quinaldic acid residue
X: Quinaric acid residue removal rate is less than 75%

<Evaluation method of metal residue removability>
The metal residue removal property was evaluated according to the following procedure.
(1) Pretreatment of wafer having silicon oxide single layer film A silicon wafer having a silicon oxide single layer film (manufactured by Advantech, “P-TEOS 1.5 μ”, silicon oxide film thickness = 1.5 μm) A section of 0.0 cm × 2.0 cm was cut, immersed in a 10% aqueous acetic acid solution for 1 minute, and then washed with ultrapure water.

(2) Preparation of aqueous solution containing metal ions To 0.1 part of zinc nitrate, 0.1 part of iron nitrate and 0.1 part of magnesium nitrate, water is added so that the total amount becomes 100 g. An aqueous solution containing 0.1% by weight of metal ions was prepared.

(3) Contamination treatment of wafer with aqueous metal ion solution
The slice of the pretreated wafer was immersed in 10 g of an aqueous solution containing metal ions for 1 minute, and then dried by nitrogen blowing, thereby attaching metal ions to the surface of the wafer.

(4) Cleaning of wafer The slice of the wafer subjected to the contamination treatment was immersed in 10 g of cleaning agent for copper wiring semiconductor. After leaving still at 25 degreeC for 3 minutes, it took out from the washing | cleaning agent.

(5) Measurement of the concentration of metal ions eluted from the wafer surface into the cleaning agent
5 g of the copper wiring semiconductor cleaning agent after the immersion was taken out, and the pH was adjusted to 3.0 with an aqueous nitric acid solution.
Thereafter, ultrapure water was added until the total amount became 10 g to prepare a measuring solution. The concentrations of zinc, iron, and magnesium metal ions contained in the measurement liquid were measured using an ICP-MS analyzer (inductively coupled plasma mass spectrometer) (manufactured by Agilent Technologies, Agilent 7500cs type).

(6) Calculation of elution amount of metal ions eluted from the wafer surface into the cleaning agent The elution amount of each metal ion was calculated using the following mathematical formula (3).

Metal _con : each metal ion concentration (ppb (ng / g)) in the measurement solution quantified by ICP-MS analysis
G1: Liquid amount (g) of the cleaning agent for copper wiring semiconductor in which the test piece is immersed
G2: Liquid amount (g) of cleaning agent for copper wiring semiconductor taken out before pH adjustment
G3: Amount of measurement liquid (g)
SSiO2: Area of a silicon oxide film in a wafer having a single layer film of silicon oxide (cm 2)

(7) Evaluation of metal residue removability The metal residue removability is evaluated from the calculated total amount of elution of each metal ion. The greater the amount of metal ion elution per wafer unit area, the greater the metal residue removability. Judged to be excellent.
Specifically, metal residue removability was determined according to the following criteria.
A: 15 ng / cm ² or more B: 10-15 ng / cm ²
Δ: 5 ng to 10 ng / cm ²
X: Less than 5 ng / cm ²

As shown in Table 1, the copper wiring semiconductor cleaning agents of Examples 1 to 8 of the present invention gave good results in the removal of benzotriazole and quinaldic acid residues and the removal of metal residues on the insulating film. It was.
On the other hand, Comparative Example 1 using an amine having no hydroxyl group, Comparative Example 2 using an aliphatic polyamine having no tertiary amino group, Comparative Example 3 not using a polyphenol compound, and a polyphenol compound having an OH position in the meta position In Comparative Example 4 used, Comparative Example 5 using a monophenol compound, and Comparative Example 6 using a polyphenol compound having an HLB not corresponding to the present invention, the quinaldic acid residue removability was poor. In Comparative Example 7 having a pH of 7.0, all of the benzotriazole residue, the quinaldic acid residue, and the metal residue are insufficient, and Comparative Example 8 having a pH of 13.5 using a large amount of a basic compound is Metal residue removability was insufficient.

The cleaning agent for copper wiring semiconductors of the present invention is capable of removing organic residues not only in the case where benzotriazole is a rust inhibitor, but also in the case of a high HLB rust inhibitor having a functional group such as a carboxyl group or a hydroxyl group. Since it is excellent and has excellent metal residue removability, it can be suitably used as a cleaning agent used in a process subsequent to the CMP process in the semiconductor manufacturing process for forming copper or copper alloy wiring.

Claims (5)

One or more amines (A) selected from the group consisting of an amine (A1) having one or more hydroxyl groups and an aliphatic polyamine (A2) represented by the following general formula (1) and not containing hydroxyl groups, 2 to 5 Polyphenol compound (B), basic compound (C), and water having a hydroxyl group, at least two of which are bonded to the ortho- or para-position of the aromatic ring and HLB of 15 to 40 Is a cleaning agent for copper wiring semiconductors, characterized in that the pH during use is 8.0 to 13.0.

[In Formula (1), m is an integer of 0-10, n is an integer of 1-10. R ^{1 to} R ⁵ each independently represents a hydrogen atom or an alkyl group, but at least one of (m + 2) nitrogen atoms is a tertiary amino group. ] The cleaning agent for a copper wiring semiconductor according to claim 1, wherein all of R ^{2 to} R ⁵ in the formula (1) representing the aliphatic polyamine (A2) are each independently an alkyl group. The cleaning agent for a copper wiring semiconductor according to claim 1 or 2, wherein the basic compound (C) is a quaternary ammonium compound (C1). Furthermore, the cleaning agent for copper wiring semiconductors in any one of Claims 1-3 which contain ascorbic acid (D) and satisfy | fill the following relational expression (1).
0.7 ≦ {[B] + [D]} / [C] ≦ 1.3 (1)
[In Formula (1), [B], [C], and [D] are the molar concentrations (mol / L of the components of polyphenol compound (B), basic compound (C), and ascorbic acid (D), respectively. ). ] The semiconductor substrate or semiconductor element manufactured using the cleaning agent in any one of Claims 1-4 in the process following chemical mechanical grinding | polishing in the semiconductor manufacturing process which forms copper or copper alloy wiring.