JP7215267B2 - Post-CMP cleaning liquid, cleaning method, and semiconductor wafer manufacturing method - Google Patents

Description

The present invention relates to a post-CMP cleaning solution, a cleaning method, and a semiconductor wafer manufacturing method.

Semiconductor wafers are processed by chemical mechanical polishing, which uses a polishing agent consisting of a water-based slurry containing polishing fine particles after depositing a metal film and an interlayer insulating film as wiring on a silicon substrate. Hereinafter, it may be abbreviated as "CMP".) The surface is planarized by a process, and a new layer is stacked on the planarized surface. Microfabrication of semiconductor wafers requires high-precision flatness in each layer, and the importance of planarization processing by CMP is extremely high.

A large amount of fine particles such as colloidal silica used in the CMP process and compounds contained in the slurry are present on the surface of the semiconductor wafer after the CMP process. is subjected to a washing step. The cleaning liquid used in the cleaning process after the CMP process is called a post-CMP cleaning liquid, and various post-CMP cleaning liquids have been proposed according to cleaning performance and the like. For example, Patent Document 1 discloses a post-CMP cleaning liquid containing an organic acid compound or the like.

Japanese translation of PCT publication No. 2009-531512

By the way, when the post-CMP cleaning solution is an acidic aqueous solution, the colloidal silica is positively charged in the aqueous solution, the surface of the semiconductor wafer is negatively charged, and an electric attractive force acts, which makes it difficult to remove the colloidal silica. have.
In addition, when the post-CMP cleaning solution is an alkaline aqueous solution, metals such as tungsten are dissolved, so there is a problem that it is difficult to use the cleaning solution for cleaning surfaces on which tungsten-containing compounds are exposed.

In order to solve these problems, it is conceivable to make the post-CMP cleaning solution neutral. It has a problem that it is inferior to In addition, if the post-CMP cleaning solution is neutral, there is a problem that organisms such as bacteria and microorganisms grow in the post-CMP cleaning solution.
The cleaning liquid disclosed in Patent Document 1 does not have a suitable antiseptic compound or amine compound, and does not have sufficient iron compound-removing properties and antibacterial properties.

The present invention has been made in view of such problems, and an object of the present invention is to provide a post-CMP cleaning solution that is excellent in iron compound removal and antibacterial properties without dissolving tungsten. Another object of the present invention is to provide a cleaning method excellent in removing iron compounds without dissolving tungsten.

Conventionally, post-CMP cleaning solutions containing various components have been studied, but as a result of extensive studies, the present inventors have found a post-CMP cleaning solution containing components (A) and (B) described below. It has been found that the post-CMP cleaning solution does not dissolve tungsten and has excellent iron compound removal properties and antibacterial properties.

That is, the gist of the present invention is as follows.
[1] A post-CMP cleaning agent containing the following components (A) and (B).
Component (A): Antibacterial agent Component (B): Carboxyl group-containing amine compound [2] Component (A) consists of a cationic antibacterial agent, a carboxylic acid antibacterial agent, a phenolic antibacterial agent, peracetic acid, and hydrogen peroxide. The post-CMP cleaning solution according to [1], containing at least one selected from the group.
[3] The post-CMP cleaning liquid according to [2], wherein the carboxylic acid-based antibacterial agent contains dehydroacetic acid.
[4] The post-CMP cleaning solution according to any one of [1] to [3], wherein component (B) contains a compound having a plurality of carboxyl groups.
[5] The post-CMP cleaning solution according to any one of [1] to [4], wherein component (B) contains ethylenediaminetetraacetic acid.
[6] The post-CMP cleaning solution according to any one of [1] to [5], further comprising the following component (C).
Component (C): Organic acid compound [7] Component (C) is selected from the group consisting of citric acid, oxalic acid, tartaric acid, succinic acid, gluconic acid, malic acid, malonic acid, maleic acid, glutaric acid and fumaric acid. The post-CMP cleaning solution according to [6], which contains at least one of
[8] The post-CMP cleaning solution according to any one of [1] to [7], further comprising the following component (D).
Component (D): pH adjuster [9] The post-CMP cleaning solution according to [8], wherein component (D) is an alkaline compound.
[10] The post-CMP cleaning solution according to any one of [1] to [9], which has a pH of 4 to 9.
[11] The method according to any one of [1] to [10], which is used for cleaning a surface on which a compound containing at least one selected from the group consisting of tungsten, ruthenium, cobalt, molybdenum, silver and aluminum is exposed. Post-CMP cleaning solution.
[12] The post-CMP cleaning solution according to any one of [1] to [10], which is used for cleaning a surface on which a tungsten-containing compound is exposed.
[13] A cleaning method for cleaning a semiconductor wafer using the post-CMP cleaning solution according to any one of [1] to [12].
[14] A method for manufacturing a semiconductor wafer, comprising the step of cleaning a semiconductor wafer using the post-CMP cleaning solution according to any one of [1] to [12].

The post-CMP cleaning solution of the present invention does not dissolve tungsten and is excellent in iron compound removal and antibacterial properties.
Moreover, the cleaning method of the present invention is excellent in removability of iron compounds without dissolving tungsten.
Furthermore, since the method for manufacturing a semiconductor wafer of the present invention includes a cleaning step that is excellent in removability of iron compounds without dissolving tungsten, malfunction of semiconductor devices can be suppressed.

Although the present invention will be described in detail below, the present invention is not limited to the following embodiments, and can be implemented with various modifications within the scope of the gist thereof. In addition, when the expression "~" is used in this specification, it is used as an expression including numerical values or physical property values before and after it.

(Post-CMP cleaning solution)
The post-CMP cleaning solution of the present invention contains the following components (A) and (B).
Component (A): Antibacterial agent Component (B): Carboxyl group-containing amine compound The post-CMP cleaning liquid is a cleaning liquid used in the cleaning process after the CMP process during the semiconductor device manufacturing process.

(Component (A))
Component (A) is an antimicrobial agent.
Since the post-CMP cleaning liquid of the present invention contains the component (A), it has excellent antibacterial properties.

Examples of component (A) include cationic antibacterial agents, carboxylic acid antibacterial agents, phenolic antibacterial agents, peracetic acid, hydrogen peroxide, and the like. These components (A) may be used individually by 1 type, and may use 2 or more types together. Among these components (A), cationic antibacterial agents, carboxylic acid antibacterial agents, phenolic antibacterial agents, peracetic acid, and hydrogen peroxide are preferable because of their excellent antibacterial properties, and do not impair the function of the post-CMP cleaning solution. Therefore, carboxylic acid-based antibacterial agents, phenol-based antibacterial agents, and hydrogen peroxide are more preferred, carboxylic acid-based antibacterial agents and phenol-based antibacterial agents are even more preferred, and dehydroacetic acid is particularly preferred.

Examples of cationic antibacterial agents include benzalkonium chloride, benzethonium chloride, domiphen bromide, and the like. These cationic fungicides may be used singly or in combination of two or more. Among these cationic antibacterial agents, benzalkonium chloride, benzethonium chloride, and domiphen bromide are preferred, and benzalkonium chloride is more preferred, because of their excellent antibacterial properties.

Carboxylic acid-based antibacterial agents include, for example, benzoic acid, sorbic acid, dehydroacetic acid, and the like. These carboxylic acid-based antibacterial agents may be used singly or in combination of two or more. Among these carboxylic acid-based antibacterial agents, benzoic acid, sorbic acid, and dehydroacetic acid are preferred, and dehydroacetic acid is more preferred, because of their excellent solubility in neutral solutions and excellent antibacterial properties.

Phenolic antibacterial agents include, for example, cresol, chlorothymol, dichloroxylenol, hexachlorophene, and the like. These phenolic antibacterial agents may be used singly or in combination of two or more. Among these phenol-based antibacterial agents, cresol, chlorothymol, dichloroxylenol, and hexachlorophene are preferred, and cresol is more preferred, because of their excellent antibacterial properties.

(Component (B))
Component (B) is a carboxyl group-containing amine compound.
Since the post-CMP cleaning solution of the present invention contains the component (B), the carboxyl groups and amino groups in the structure of the component (B) are coordinated with the metal ions, promoting the dissolution of the iron compound in the post-CMP cleaning solution. Therefore, it is excellent in removing iron compounds.

Examples of carboxyl group-containing amine compounds include ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, triethylenetetraaminehexaacetic acid, hydroxyethyliminodiacetic acid, histidine and the like. These carboxyl group-containing amine compounds may be used singly or in combination of two or more. Among these carboxyl group-containing amine compounds, compounds having a plurality of carboxyl groups are preferable because they are excellent in removing iron compounds, and ethylenediaminetetraacetic acid is more preferable because they are more excellent in antibacterial properties.

(Component (C))
The post-CMP cleaning solution of the present invention preferably contains the following component (C) in addition to the components (A) to (B) because it is excellent in removing iron compounds.
Component (C): organic acid compound

Examples of organic acid compounds include citric acid, oxalic acid, tartaric acid, succinic acid, gluconic acid, malic acid, malonic acid, maleic acid, glutaric acid, and fumaric acid. These organic acid compounds may be used individually by 1 type, and may use 2 or more types together. Among these organic acid compounds, citric acid, oxalic acid, tartaric acid, succinic acid, gluconic acid, malic acid, malonic acid, maleic acid, glutaric acid, and fumaric acid are preferred because they are excellent in removing iron compounds, and citric acid is preferred. , tartaric acid is more preferred, and citric acid is even more preferred.

(Component (D))
Since the pH of the post-CMP cleaning liquid can be adjusted, the post-CMP cleaning liquid of the present invention preferably contains the following component (D) in addition to components (A) to (C).
Component (D): pH adjuster

Examples of pH adjusters include acidic compounds and alkaline compounds. Among these pH adjusters, alkaline compounds are preferred because they can adjust the pH to a preferred range, which will be described later.

Examples of alkaline compounds include inorganic alkalis and organic alkalis. These alkaline compounds may be used singly or in combination of two or more. Among these alkaline compounds, inorganic alkalis and organic alkalis are preferable because the alkaline compounds themselves can be easily produced, and ammonia, quaternary ammonium hydroxides, and alkanolamine compounds are more preferable because they do not contain metal components. Ammonia and quaternary ammonium hydroxide are more preferable, and ammonia is particularly preferable, since the pH adjuster itself can be prevented from remaining on the semiconductor wafer after cleaning.

(Component (E))
The cleaning liquid of the present invention preferably contains the following component (E) in addition to the components (A) to (D), because it is excellent in removing fine particles.
Component (E): water

The cleaning solution of the present invention may contain components other than components (A) to (E) within a range that does not impair the effects of the present invention.

Other components include, for example, surfactants and etching inhibitors.

Components (A) to (D) and other components may be in the form of salts.

(Physical properties of cleaning solution after CMP)
The pH of the cleaning solution after CMP is preferably 4-9, more preferably 5-8. If the post-CMP cleaning solution has a pH of 4 or higher, the colloidal silica also negatively charges the surface of the semiconductor wafer, and an electrical repulsive force acts, facilitating the removal of the colloidal silica. Further, when the post-CMP cleaning liquid has a pH of 9 or less, the dissolution of tungsten can be suppressed.

(Mass ratio of components)
The mass ratio of component (A) to component (B) (mass of component (A)/mass of component (B)) is preferably 0.1-100, more preferably 0.2-50. When the mass ratio of component (A) to component (B) is at least the lower limit, excellent antibacterial properties are achieved. Moreover, when the mass ratio of the component (A) to the component (B) is equal to or lower than the upper limit, the iron compound removability is excellent.

When the post-CMP cleaning solution of the present invention contains component (C), the mass ratio of component (A) to component (C) (mass of component (A)/mass of component (C)) is 0.1 to 100. Preferably, 0.2 to 50 is more preferable. When the mass ratio of component (A) to component (C) is at least the lower limit, excellent antibacterial properties are obtained. Moreover, when the mass ratio of the component (A) to the component (C) is equal to or less than the upper limit, the iron compound removability is excellent.

When the post-CMP cleaning solution of the present invention contains component (D), the mass ratio of component (A) to component (D) (mass of component (A)/mass of component (D)) is 0.1 to 100. Preferably, 0.2 to 50 is more preferable. When the mass ratio of component (A) to component (D) is at least the lower limit, excellent antibacterial properties are obtained. Moreover, when the mass ratio of the component (A) to the component (D) is equal to or lower than the upper limit, the pH of the post-CMP cleaning liquid can be easily adjusted.

When the post-CMP cleaning solution of the present invention contains component (C), the mass ratio of component (C) to component (B) (mass of component (C)/mass of component (B)) is 0.1 to 100. Preferably, 0.2 to 50 is more preferable. When the mass ratio of component (C) to component (B) is equal to or higher than the lower limit, the iron compound removability is excellent. Moreover, when the mass ratio of the component (C) to the component (B) is equal to or lower than the upper limit, the iron compound removability is excellent.

When the post-CMP cleaning solution of the present invention contains component (D), the mass ratio of component (B) to component (D) (mass of component (B)/mass of component (D)) is 0.01 to 100. Preferably, 0.02 to 50 is more preferable. When the mass ratio of the component (B) to the component (D) is at least the lower limit, the iron compound removal properties are excellent. Moreover, when the mass ratio of the component (B) to the component (D) is equal to or less than the upper limit, the pH of the post-CMP cleaning liquid can be easily adjusted.

When the post-CMP cleaning solution of the present invention contains component (C) and component (D), the mass ratio of component (C) to component (D) (mass of component (C)/mass of component (D)) is 0. 0.1 to 100 is preferred, and 0.2 to 50 is more preferred. When the mass ratio of the component (C) to the component (D) is at least the lower limit, the iron compound removal properties are excellent. Further, when the mass ratio of the component (C) to the component (D) is equal to or lower than the upper limit, the pH of the post-CMP cleaning liquid can be easily adjusted.

(Content rate in washing solution after CMP)
The content of component (A) is preferably 0.001% by mass to 30% by mass, more preferably 0.005% by mass to 20% by mass, and more preferably 0.01% by mass to 1% by mass in 100% by mass of the cleaning liquid. More preferred. When the content of component (A) is at least the lower limit, excellent antibacterial properties are obtained. Further, when the content of the component (A) is equal to or less than the upper limit, the solubility in a neutral solution is excellent, and the function as a post-CMP cleaning liquid is not impaired.

The content of component (B) is preferably 0.0001% by mass to 10% by mass, more preferably 0.0005% by mass to 5% by mass, and 0.001% by mass to 0.1% by mass in 100% by mass of the cleaning liquid. % is more preferred. When the content of the component (B) is at least the lower limit, the iron compound removability is excellent. Moreover, when the content of the component (B) is equal to or less than the upper limit, the solubility in a neutral solution is excellent, and the pH of the post-CMP cleaning liquid can be easily adjusted.

When the post-CMP cleaning solution of the present invention contains component (C), the content of component (C) is preferably 0.001% by mass to 30% by mass, more preferably 0.005% by mass to 20% by mass, based on 100% by mass of the cleaning solution. %, more preferably 0.01% by mass to 1% by mass. When the content of the component (C) is at least the lower limit, the iron compound removability is excellent. Further, when the content of the component (C) is equal to or less than the upper limit, the pH of the post-CMP cleaning liquid can be easily adjusted.

When the post-CMP cleaning solution of the present invention contains component (D), the content of component (D) is preferably 0.0001% by mass to 10% by mass, more preferably 0.0005% by mass to 5% by mass, based on 100% by mass of the cleaning solution. % is more preferred, and 0.001% by mass to 0.1% by mass is even more preferred. When the content of component (D) is at least the lower limit, the pH of the post-CMP cleaning liquid can be easily adjusted. Further, when the content of the component (D) is equal to or less than the upper limit, the function as the post-CMP cleaning liquid is not impaired.

When the post-CMP cleaning solution of the present invention contains other components, the content of the other components is preferably 10% by mass or less, more preferably 0% by mass to 1% by mass, more preferably 0% by mass to 100% by mass, based on 100% by mass of the cleaning solution. 0.1% by mass is more preferred. When the content of other components is equal to or less than the upper limit, the effects of the other components can be imparted without impairing the effects of the present invention.

When the post-CMP cleaning solution of the present invention contains component (E), the content of component (E) is the balance of components other than component (E) (components (A) to component (D) and other components). is preferred.

(Manufacturing method of cleaning solution after CMP)
The method for producing the post-CMP cleaning solution of the present invention is not particularly limited, and it can be produced by mixing components (A) to (D) and, if necessary, component (E) and other components. can.
The order of mixing is not particularly limited, and all components may be mixed at once, or some components may be premixed and then the remaining components mixed.

In the method for producing the post-CMP cleaning solution of the present invention, each component may be blended so that the content is suitable for cleaning. A post-CMP solution may be prepared by preparing a post-CMP solution containing a high content of each component other than the above, and then diluting it with the component (E) before washing.
The dilution ratio can be appropriately set according to the object to be washed, but is preferably 30-fold to 200-fold, more preferably 40-fold to 150-fold.

(Washing target)
Examples of objects to be cleaned with the post-CMP cleaning solution of the present invention include semiconductor wafers such as semiconductors, glasses, metals, ceramics, resins, magnetic substances, and superconductors. Among these objects to be cleaned, semiconductor wafers having a surface where metal is exposed are preferable because iron compounds and fine particles can be removed by cleaning in a short period of time. A semiconductor wafer having a surface on which a compound containing at least one selected from the group consisting of ruthenium, cobalt, molybdenum, silver and aluminum is exposed is more preferable, and since the effect of the present invention is further required, it contains tungsten. More preferred are semiconductor wafers having surfaces on which compounds are exposed.

Examples of metals include tungsten, ruthenium, cobalt, molybdenum, silver, and aluminum. Among these metals, tungsten, silicon, ruthenium, cobalt, molybdenum, silver, and aluminum are preferable because the effects of the present invention are more required, and tungsten is more preferable because the effects of the present invention are further required. .

(CMP)
The post-CMP cleaning solution of the present invention does not dissolve tungsten and is excellent in iron compound removal and antibacterial properties. It is particularly suitable for cleaning semiconductor wafers with exposed surfaces after the CMP process.

A chemical mechanical polishing (CMP) process refers to a process for mechanically processing and planarizing the surface of a semiconductor wafer. Usually, in the CMP process, a special device is used, the back surface of the semiconductor wafer is adsorbed to a jig called a platen, the front surface of the semiconductor wafer is pressed against a polishing pad, and an abrasive containing abrasive particles is dripped onto the polishing pad to remove the semiconductor. Polish the surface of the wafer.

CMP is performed by rubbing an object to be polished against a polishing pad using an abrasive.
Examples of abrasives include abrasive fine particles such as colloidal silica (SiO ₂ ), fumed silica (SiO ₂ ), alumina (Al ₂ O ₃ ), and ceria (CeO ₂ ). These abrasive fine particles are the main cause of fine particle contamination of the object to be polished, but the post-CMP cleaning solution of the present invention has the effect of removing the fine particles adhering to the object to be polished, dispersing them in the cleaning solution, and preventing redeposition. Therefore, it is highly effective in removing particulate contamination.

The abrasive may contain additives such as an oxidizing agent, a dispersant, and an anticorrosive agent in addition to the fine abrasive particles.

(Washing conditions)
The object to be cleaned is preferably cleaned by a method in which the post-CMP cleaning solution of the present invention is brought into direct contact with the object to be cleaned.
Examples of the method of bringing the post-CMP cleaning solution of the present invention into direct contact with an object to be cleaned include, for example, a dip method in which a cleaning tank is filled with the post-CMP cleaning solution of the present invention and the object to be cleaned is immersed; Examples include a spin type in which the object to be cleaned is rotated at high speed while the post-cleaning liquid is flowing; and a spray type in which the cleaning object is cleaned by spraying the post-CMP cleaning liquid of the present invention. Among these methods, the spin method and the spray method are preferable because they can remove contamination more efficiently in a short time.

Devices for performing such cleaning include, for example, a batch-type cleaning device that simultaneously cleans a plurality of cleaning targets contained in a cassette, and a single-wafer cleaning device that cleans a single cleaning target by attaching it to a holder. equipment and the like. Among these apparatuses, the single-wafer cleaning apparatus is preferable because it can shorten the cleaning time and reduce the use of the post-CMP cleaning solution of the present invention.

As for the method for cleaning the object to be cleaned, it is preferable to use physical force for cleaning, because it further improves the ability to remove contamination caused by fine particles adhering to the object and shortens the cleaning time. Scrub cleaning using a cleaning brush, frequency 0.5. Ultrasonic cleaning of megahertz or higher is more preferable, and scrub cleaning using a resin brush is even more preferable because it is more suitable for cleaning after CMP.
The material of the resin brush is not particularly limited, but polyvinyl alcohol and polyvinyl formal are preferable because the resin brush itself can be easily manufactured.

The cleaning temperature may be room temperature, or may be increased to 30 to 70° C. within a range that does not impair the performance of the semiconductor wafer.

(Washing method)
The cleaning method of the present invention is a method of cleaning a semiconductor wafer using the post-CMP cleaning solution of the present invention, and is as described above.

(Method for manufacturing semiconductor wafer)
The semiconductor wafer manufacturing method of the present invention is a method including the step of cleaning the semiconductor wafer using the post-CMP cleaning solution of the present invention, as described above.

The present invention will be described in more detail below using examples, but the present invention is not limited to the description of the following examples unless it departs from the gist thereof.

(material)
Component (A-1): dehydroacetic acid (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)
Component (A-2): cresol (manufactured by Tokyo Chemical Industry Co., Ltd.)
Component (B-1): Ethylenediaminetetraacetic acid (manufactured by Dojindo Laboratories)
Component (B-2): Hydroxyethyliminodiacetic acid (manufactured by Cherest Co., Ltd.)
Component (B-3): Histidine (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.)
Component (B'-1): diethanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.)
Component (B'-2): isopropanolamine (manufactured by Tokyo Chemical Industry Co., Ltd.)
Component (C-1): citric acid (manufactured by Tokyo Chemical Industry Co., Ltd.)
Component (D-1): Ammonia (manufactured by Tokyo Chemical Industry Co., Ltd.)
Component (E-1): water

(pH measurement)
The post-CMP cleaning solutions obtained in Examples and Comparative Examples were stirred in a constant temperature bath at 25° C. with a magnetic stirrer, and the pH was measured using a pH meter (model name “D-24”, manufactured by HORIBA, Ltd.). pH was measured.

(Tungsten solubility measurement)
The silicon substrate on which the tungsten film was formed was cut into 20 mm squares, and the substrate was immersed in 20 mL of the post-CMP cleaning solution obtained in Examples and Comparative Examples at 25° C. for 30 minutes. After that, the substrate was taken out, and the concentration of tungsten in the post-CMP cleaning solution after immersion was measured by an ICP emission spectrometer (model name “SPS1700HVR”, manufactured by Seiko Instruments). From the measured tungsten concentration, the tungsten elution rate (Å/min) in 30 minutes was calculated to evaluate the tungsten solubility.

(Iron compound removal measurement)
A silicon substrate (manufactured by Advantech Co., Ltd.) on which silicon dioxide was vapor-deposited to a thickness of 0.3 μm was subjected to chemical mechanical polishing (CMP) using an abrasive containing silica and iron nitrate. While supplying the post-CMP cleaning solution obtained in the example to the substrate surface, the substrate surface was cleaned using a polyvinyl alcohol brush. The obtained substrate after cleaning after CMP was immersed in 20 g of a 10% by mass hydrofluoric acid aqueous solution at 24° C. for 2 hours. Fisher Scientific) was used to measure the residual iron compound concentration (10 ¹⁰ atms/cm ² ) on the substrate surface to evaluate the iron compound removability.

(Antibacterial measurement)
The test was conducted based on the Japanese Pharmacopoeia 17th Edition Preservative efficacy test method. As the test fungi, Penicillium aurantiogriseum (NBRC 7733) and Aspergillus brasiliensis (NBRC 9455) were used. The test bacteria were inoculated on a potato dextrose agar medium (PDA), cultured at 25°C for 1 week, and then prepared using a 0.05% by mass Tween 80 solution so that the number of spores was 10 ⁷ /mL. It was used as a bacterial solution. 10 mL of the post-CMP cleaning solution obtained in Examples and Comparative Examples was aseptically dispensed into a sterilized container, and 0.1 mL of the test bacterial solution was inoculated to prepare a test sample, which was cultured at 25°C. SCDLP medium was inoculated with a 10-fold dilution of the test sample on day 14 of test sample culture. Three days after the inoculation, the colonies formed on the agar medium were counted, the number of viable bacteria (10,000) was calculated, and the antimicrobial activity was evaluated.

[Example 1]
In 100% by mass of the cleaning liquid, 0.050% by mass of component (A-1), 0.005% by mass of component (B-1), 0.050% by mass of component (C-1), and 0.050% by mass of component (D-1 ) was 0.014% by mass, and component (E-1) was the balance, to obtain a post-CMP cleaning solution.
Table 1 shows the evaluation results of the obtained post-CMP cleaning liquid.

[Comparative Examples 1 and 2]
A post-CMP cleaning liquid was obtained in the same manner as in Example 1 except that the types and contents of the raw materials shown in Table 1 were used.
Table 1 shows the evaluation results of the obtained post-CMP cleaning liquid.

As can be seen from Table 1, the post-CMP cleaning solutions obtained in Examples 1 to 4 did not dissolve tungsten, and were excellent in iron compound removal and antibacterial properties.
On the other hand, the post-CMP cleaning solution obtained in Comparative Example 1 did not contain component (A) and component (B), and therefore did not dissolve tungsten, but was inferior in iron compound removal and antibacterial properties. The post-CMP cleaning solution obtained in Comparative Example 2 did not contain the component (A) and therefore did not dissolve tungsten, but was slightly inferior in iron compound removal properties and inferior in antibacterial properties. The post-CMP cleaning solution obtained in Comparative Example 3 did not contain the component (B), and therefore did not dissolve tungsten, and had excellent antibacterial properties, but was inferior in removing iron compounds. In addition, the post-CMP cleaning liquids obtained in Comparative Examples 4 and 5 did not dissolve tungsten and had excellent antibacterial properties because the amine compound containing no carboxyl group was used as the component (B) instead of the amine compound containing a carboxyl group. , inferior in iron compound removal properties. Comparative Example 6 did not contain the component (A) and the component (B) and was made acidic, so it did not dissolve tungsten, but was inferior in iron compound removing properties and antibacterial properties. Furthermore, Comparative Example 7 did not contain component (A) and component (B) and was alkaline, so it was excellent in antibacterial properties, but it dissolved tungsten and was inferior in iron compound removal properties.

The post-CMP cleaning solution of the present invention does not dissolve tungsten and is excellent in iron compound removal and antibacterial properties. It is particularly suitable for cleaning semiconductor wafers with exposed surfaces after the CMP process.

Claims (13)

containing the following components (A) and (B) ,
A post-CMP cleaning agent for cleaning surfaces where tungsten-containing compounds are exposed .
Component (A): antibacterial agent Component (B): carboxyl group-containing amine compound 2. The post-CMP cleaning liquid according to claim 1, wherein component (A) contains at least one selected from the group consisting of cationic antibacterial agents, carboxylic acid antibacterial agents, phenolic antibacterial agents, peracetic acid and hydrogen peroxide. 3. The post-CMP cleaning liquid according to claim 2, wherein the carboxylic acid-based antibacterial agent contains dehydroacetic acid. The post-CMP cleaning solution according to any one of claims 1 to 3, wherein component (B) contains a compound having a plurality of carboxyl groups. The post-CMP cleaning solution according to any one of claims 1 to 4, wherein component (B) comprises ethylenediaminetetraacetic acid. The CMP according to any one of claims 1 to 5, wherein the mass ratio of component (A) to component (B) (mass of component (A)/mass of component (B)) is 0.1 to 100. Post-wash liquid. The post-CMP cleaning solution according to any one of claims 1 to 6 , further comprising the following component (C).
Component (C): organic acid compound 8. Component (C) comprises at least one selected from the group consisting of citric acid, oxalic acid, tartaric acid, succinic acid, gluconic acid, malic acid, malonic acid, maleic acid, glutaric acid and fumaric acid. Post-CMP cleaning solution as described. The post-CMP cleaning solution according to any one of claims 1 to 8 , further comprising the following component (D).
Component (D): pH adjuster The post-CMP cleaning solution according to claim 9 , wherein component (D) is an alkaline compound. The post-CMP cleaning solution according to any one of claims 1 to 10 , which has a pH of 4 to 9. A cleaning method for cleaning a semiconductor wafer using the post-CMP cleaning solution according to any one of claims 1 to 11 . A method for manufacturing a semiconductor wafer, comprising a step of cleaning a semiconductor wafer using the post-CMP cleaning solution according to any one of claims 1 to 11 .