JP2001026890A - Metal corrosion inhibitor, cleaning liquid composition containing the same, and cleaning method using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To add a corrosion inhibitor for a metal having no corrosiveness when cleaning a metal, particularly tungsten or a tungsten alloy, and to add a corrosion inhibitor to a cleaning solution for a semiconductor device having a tungsten wiring in a metal wiring or the like. Accordingly, a cleaning liquid composition capable of removing impurities without corroding metal wiring and a method for cleaning a semiconductor device using the cleaning liquid composition are provided. SOLUTION: Corrosion inhibitors for metals, particularly tungsten, comprising at least one compound selected from triazoles containing at least one amino group or thiol group in the molecule, polyethyleneimine and polyamine sulfone represented by the formula (1) A cleaning liquid composition in which a corrosion inhibitor is added to a cleaning liquid suitable for cleaning a metal to be cleaned, and a method for cleaning a semiconductor device using the cleaning liquid composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a metal corrosion inhibitor, a cleaning solution composition containing the same, and a cleaning method using the same, and more particularly, it has no corrosiveness to tungsten or a tungsten alloy, and therefore has a tungsten-based wiring. The present invention relates to a cleaning liquid composition that can provide a cleaning liquid optimal for cleaning in a semiconductor device manufacturing process having the following.

[0002]

2. Description of the Related Art In recent years, various materials have been developed for higher integration and higher performance of semiconductor devices and multilayer wiring. Among them, high melting point metal such as tungsten is used as a cap metal on the main wiring film such as aluminum or its alloy film in order to supplement the mechanical strength of aluminum and form stable multilayer wiring in multi-layer wiring. Lamination is often performed.

[0003] Tungsten is also excellent in embedding performance in a contact hole by a chemical vapor deposition method, and is often used as a contact metal for connecting an upper wiring and a lower wiring by taking advantage of this.

In recent years, a contact forming technique by a damascene method using a chemical mechanical polishing method (Chemical Mechanical Polishing, hereinafter abbreviated as CMP) using a special abrasive and a polishing pad has been developed and introduced into a mass production line. It is getting. However, since the formation of the cap metal on the aluminum-based wiring film described above involves a lithography process and a dry etching process, a large number of particles such as resist residues and metal adhere to the front and back surfaces of the wafer, and a CMP process. In, the polishing particles generated after polishing, and polishing debris generated by polishing, and a large amount of metal impurities and the like contained in the polishing agent and the polishing pad, etc. adhere to the front and rear surfaces of the wafer. These need to be removed.

Generally, to remove particles on the wafer surface, an alkaline solution such as ammonium hydroxide,
Acidic solutions are used to remove metal impurities, but these are often used in combination with hydrogen peroxide to further enhance the cleaning effect.

However, among metals, tungsten is weak against oxidizing chemicals such as hydrogen peroxide and is easily corroded. Therefore, when the surface of the wafer where the tungsten wiring is exposed is cleaned with a cleaning solution containing an oxidizing chemical solution, a problem occurs that the cleaned tungsten surface is eroded by corrosion.

Since the wiring pattern of a semiconductor device is extremely fine, even if the total amount of corrosion is suppressed by a corrosion inhibitor, pitting occurs, the surface condition is roughened, and the device performance is adversely affected. .

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a cleaning liquid which is not corrosive to metals, especially tungsten or a tungsten alloy, and is therefore optimal for cleaning semiconductor devices having tungsten metal wiring. It is an object of the present invention to provide a metal corrosion inhibitor capable of providing the following, a cleaning solution composition containing the corrosion inhibitor, and a cleaning method using the cleaning solution composition.

[0009]

That is, the first aspect of the present invention is to provide a triazole containing at least one amino group or thiol group in a molecule, polyethyleneimine and a polyamine sulfone represented by the following formula (2). It relates to a metal corrosion inhibitor containing one or more selected compounds.

[0010]

Embedded image

In the formula, R ₁ and R ₂ each independently represent hydrogen, C
H ₃ , C ₂ H ₅ or CH ₂ C ₆ H ₅ is shown. X- represents an anionic group, and n is 30 to 200.

The metal corrosion inhibitor of the present invention comprises at least one compound selected from triazoles containing at least one amino group or thiol group in the molecule, polyethyleneimine and polyamine sulfone represented by the above formula (2). Is done. Among them, particularly preferred triazoles include 3-aminotriazole, and polyethyleneimine having a molecular weight of 300 to 1
And a particularly preferred compound among the polyamine sulfones represented by Chemical Formula 2 is a polyamine sulfone in which R ₁ and R ₂ are hydrogen. These corrosion inhibitors may be used alone or as a mixture. Although the corrosion inhibitor of the present invention prevents metal corrosion, it is possible to obtain a large corrosion inhibitory effect on tungsten or a tungsten alloy.

The anionic group is preferably a halogen ion, a hydrogen sulfate ion, a hydroxyl ion, a thiocyanate ion, an isothiocyanate ion or an alkyl sulfate ion.

A second aspect of the present invention relates to a cleaning solution composition containing the above-mentioned corrosion inhibitor. In the present invention, a cleaning liquid containing no corrosion inhibitor is simply referred to as a “cleaning liquid”, and a cleaning liquid containing a corrosion inhibitor is referred to as a “cleaning liquid composition” to distinguish between the two.

[0015] By mixing the corrosion inhibitor of the present invention with a cleaning solution, a cleaning solution composition having no corrosiveness to metals, particularly tungsten, can be provided. Here, examples of the cleaning liquid include cleaning liquids for semiconductor devices that have been conventionally used. In cleaning a semiconductor device with exposed tungsten, the cleaning liquid composition containing the corrosion inhibitor of the present invention can sufficiently exhibit the effect of preventing the corrosion of tungsten.

As the cleaning solution, any of an alkaline solution, a neutral solution and an acidic solution can be used.

The alkaline solution is not particularly limited.
An aqueous solution of an inorganic compound such as sodium hydroxide, potassium hydroxide, or ammonium hydroxide, or an aqueous solution of an organic compound such as tetramethylammonium hydroxide or choline can be used. Among them, compounds containing no metal salt such as ammonium hydroxide, tetramethylammonium hydroxide, and choline purified by removing particles and metal impurities for use in semiconductor devices are particularly preferable. These alkaline solutions can be used alone or as a mixture.

Water is generally used as the neutral solution. Water is pure water from which particles and metal impurities have been removed, and is used in combination with an oxidizing agent described below.

On the other hand, acidic solutions include hydrochloric acid, hydrofluoric acid,
An aqueous solution of an inorganic acid such as sulfuric acid or nitric acid, or an aqueous solution of an organic acid such as oxalic acid, citric acid, malonic acid, malic acid, fumaric acid, or maleic acid can be used. Hydrochloric acid, hydrofluoric acid, sulfuric acid, oxalic acid and citric acid purified by removing impurities are particularly preferred. These acidic solutions can be used alone or as a mixture.

Further, in general, these alkaline solutions, acidic solutions and pure water are often used by mixing with hydrogen peroxide among oxidizing agents in order to enhance the cleaning effect of the cleaning solution. However, among metals, in the case of tungsten or a tungsten alloy, corrosion proceeds significantly when washed with a conventional alkaline cleaning solution or hydrogen-containing cleaning solution containing hydrogen peroxide. It is particularly effective.

The amount of the corrosion inhibitor mixed with the cleaning solution is preferably 0.0001 to 10% by weight, more preferably 0.001 to 5% by weight, as the concentration in the cleaning solution. If the concentration is too low, it may not be possible to obtain a sufficient corrosion-inhibiting effect, while if the concentration is too high, the amount of the corrosion inhibitor adsorbed on the surface of the semiconductor device may increase, thereby deteriorating the performance of the device. This is not preferable because it may have an adverse effect. The amount of hydrogen peroxide mixed with the cleaning solution is
The concentration in the cleaning solution is preferably 0.0001 to 20% by weight, more preferably 0.1 to 10% by weight.

In order to obtain a cleaning liquid composition having a corrosion preventing effect, the cleaning liquid, the corrosion inhibitor of the present invention and hydrogen peroxide may be directly mixed. Alternatively, the corrosion inhibitor may be mixed in advance with a hydrogen peroxide solution or water, and the mixed solution may be mixed with a cleaning solution.

Further, in addition to the case where tungsten is used alone, there are also cases where aluminum or copper or the like is used in combination for the metal wiring of a semiconductor device, and a mixture of a corrosion inhibitor having a function of preventing corrosion of aluminum or copper is used. Is also possible.

A third aspect of the present invention relates to a method for cleaning a semiconductor device having a metal wiring with the cleaning liquid composition.

The method for cleaning a wafer using the cleaning liquid composition of the present invention is not particularly limited, and an ordinary cleaning method can be used. An immersion cleaning method by directly immersing the wafer in the cleaning liquid, a method in which ultrasonic irradiation is used in combination with the immersion cleaning method, a brush cleaning method in which the cleaning liquid is sprayed onto the wafer surface with a brush, a brush cleaning method and ultrasonic irradiation Can be used in combination. When washing, the washing liquid can be heated.

[0026]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail by way of examples, but the present invention is not limited to these examples.

As a method of evaluating the corrosion prevention effect in the examples and comparative examples, a test piece of a silicon wafer on which a tungsten film 10000 化学 was formed by a chemical vapor deposition method was immersed in a cleaning solution composition and a cleaning solution for 30 minutes. The dissolution rate was calculated from the change in the thickness of the W film before and after immersion. Here, the film thickness was measured using a sheet resistance measuring device manufactured by Napson Corporation, and a method of converting the film thickness from the sheet resistance value was used. The surface before and after the immersion was observed with an electron microscope, and the state of the surface of the tungsten film was observed.

Examples 1 to 12 and Comparative Examples 1 to 4 An aqueous solution containing 55% by weight of hydrogen peroxide was used as a washing liquid.
A predetermined amount of the corrosion inhibitor of the present invention shown in Table 1 was added to obtain a cleaning liquid composition of the present invention. As comparative examples, a cleaning solution to which no corrosion inhibitor was added and a cleaning composition to which a corrosion inhibitor other than the present invention was added were used. Table 1 shows the results. From Table 1, it was confirmed that the corrosion inhibitor of the present invention was extremely effective in preventing the corrosion of tungsten against a solution of hydrogen peroxide alone.

[0029]

[Table 1]

Examples 13 to 24 and Comparative Examples 5 to 8 An alkaline aqueous solution containing 1% by weight of ammonia and 5% by weight of hydrogen peroxide was used as a washing solution, and a predetermined amount of the corrosion inhibitor of the present invention shown in Table 2 was used. This was added to obtain the cleaning liquid composition of the present invention. As a comparative example, a cleaning solution to which no corrosion inhibitor was added or a cleaning composition to which a corrosion inhibitor other than the present invention was added was used. Table 2 shows the results. From Table 2, it was confirmed that the corrosion inhibitor of the present invention was extremely effective in preventing the corrosion of tungsten with respect to the cleaning liquid composition comprising a mixed solution of ammonia and hydrogen peroxide.

[0031]

[Table 2]

Examples 25 to 32 and Comparative Examples 9 to 11 Aqueous solutions containing the amounts shown in Table 3 for ammonia, TMAH (tetramethylammonium hydroxide) and hydrogen peroxide were used as washing liquids, and the present invention described in Table 3 was used. Was added in a predetermined amount to obtain a cleaning liquid composition of the present invention. As a comparative example, a cleaning solution to which no corrosion inhibitor was added was used. Table 3 shows the results. From Table 3, it can be seen that the corrosion inhibitor of the present invention is composed of ammonia water alone or ammonia or TM
It has been confirmed that a cleaning solution composition comprising a mixed aqueous solution of AH (tetramethylammonium hydroxide) and hydrogen peroxide is extremely effective in preventing tungsten corrosion.

[0033]

[Table 3]

[0034]

As described above, the first metal corrosion inhibitor according to the present invention comprises triazoles containing at least one amino group or thiol group in the molecule, polyethyleneimine and polyamine sulfone represented by the formula (1). Contains one or more selected compounds to prevent corrosion of metals, especially tungsten or tungsten alloys.

According to the second aspect of the present invention, the metal corrosion inhibitor is added to a cleaning solution suitable for the metal to be cleaned.
When the metal is cleaned, it removes impurities and prevents corrosion of the basic metal, especially pitting.

According to the third aspect of the present invention, since the metal wiring, particularly the tungsten wiring, in the semiconductor device is cleaned by the cleaning liquid composition, impurities are removed and the surface of the metal wiring is roughened or pitched. Or not.

Continuation of the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (reference) C11D 7/54 C11D 7/54 17/08 17/08 C23F 11/00 C23F 11/00 B C23G 1/06 C23G 1 / 06 H01L 21/304 647 H01L 21/304 647A (72) Inventor Masayuki Takashima 6th Kitahara, Tsukuba-shi, Ibaraki Sumitomo Chemical Co., Ltd. F-term (reference) 3B201 AA03 AB01 BB02 BB92 BB93 BB96 CB01 4H003 BA12 DA15 EA23 EB19 EB20 EB21 EB38 ED02 EE04 FA15 FA28 4K053 PA09 PA11 RA13 RA14 RA15 RA16 RA17 RA19 RA21 RA22 RA23 RA45 RA47 RA52 RA55 RA59 RA63 SA04 SA06 SA17 SA18 4K062 AA03 BA11 BA14 BB12 BB18 BB21 DA01 FA09 GA01

Claims (18)

[Claims] 1. A metal corrosion inhibitor comprising at least one compound selected from the group consisting of triazoles containing at least one amino group or thiol group in the molecule, polyethyleneimine and polyamine sulfone represented by the formula 1. Embedded image In the formula, R ₁ and R ₂ are each independently hydrogen, CH ₃ , C ₂ H ₅
Or CH ₂ C ₆ H ₅ . X- represents an anionic group, and n is 30 to 200. 2. The corrosion inhibitor according to claim 1, wherein the triazole is 3-aminotriazole. 3. Polyethyleneimine having a molecular weight of 300 to 1
The corrosion inhibitor according to claim 1, which has a molecular weight of 000. 4. An anionic group comprising a halogen ion, a hydrogen sulfate ion, a hydroxyl ion, a thiocyanate ion,
The corrosion inhibitor according to any one of claims 1 to 3, which is an isothiocyanate ion or an alkyl sulfate ion. 5. The corrosion inhibitor according to claim 1, wherein the metal is tungsten or a tungsten alloy. 6. The corrosion inhibitor according to claim 1, wherein the metal is a metal wiring in a semiconductor device. 7. The corrosion inhibitor according to claim 6, wherein the metal wiring is a tungsten metal wiring. 8. A cleaning liquid composition comprising the corrosion inhibitor according to claim 1 and a cleaning liquid. 9. The cleaning liquid composition according to claim 8, which is used for cleaning in a process of manufacturing a semiconductor device having metal wiring. 10. The cleaning liquid composition according to claim 9, wherein the metal wiring is a tungsten metal wiring. 11. The cleaning liquid according to claim 8, wherein the cleaning liquid is an alkaline solution.
The cleaning liquid composition according to any one of claims 10 to 10. 12. The cleaning liquid composition according to claim 8, wherein the cleaning liquid is an alkaline solution containing an oxidizing substance. 13. The cleaning solution composition according to claim 11, wherein the alkaline solution is an aqueous solution containing at least one of ammonia and tetramethylammonium hydroxide. 14. The cleaning liquid according to claim 8, wherein the cleaning liquid is an acidic solution.
0. The cleaning liquid composition according to any one of the above. 15. The cleaning liquid composition according to claim 8, wherein the cleaning liquid is an acidic solution containing an oxidizing substance. 16. The cleaning liquid composition according to claim 8, wherein the cleaning liquid is water containing an oxidizing substance. 17. The cleaning liquid composition according to claim 12, wherein the oxidizing substance is hydrogen peroxide. 18. A cleaning method, comprising cleaning a semiconductor device having a metal wiring with the cleaning liquid composition according to claim 8.