WO2002000965A1

WO2002000965A1 - Corrosion protective agent

Info

Publication number: WO2002000965A1
Application number: PCT/JP2001/005504
Authority: WO
Inventors: Corporation Nec
Original assignee: Koito, Tatsuya; Hirano, Keiji; Aoki, Hidemitsu; Tomimori, Hiroaki
Priority date: 2000-06-28
Filing date: 2001-06-27
Publication date: 2002-01-03

Abstract

A corrosion protective agent for protecting the corrosion of a metal film formed on a semiconductor wafer, characterized in that it comprises a heterocyclic compound having a six-membered ring containing a nitrogen atom.

Description

Specification

Anticorrosive technology

The present invention relates to an anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor wafer, and more particularly to an anticorrosion agent for preventing corrosion of corrosive metals such as copper formed on a semiconductor wafer. .

Background art

In a semiconductor device manufacturing process, a metal film that has been patterned into a predetermined shape is formed on a semiconductor wafer, and wirings and connection plugs are formed. In the process of forming such interconnects and connection plugs, anticorrosion technology for preventing corrosion of the metal film and preventing an increase in interconnect resistance is important. In particular, in recent years, copper has been widely used as a constituent material of wiring and connection plugs from the viewpoint of achieving high-speed operation of devices, and the demand for corrosion prevention of metal films has become more severe than ever. I have. This is because copper has excellent properties such as excellent electrification-migration resistance and low resistance, but easily oxidizes and etches, and is easily corroded.

An example of a process in which corrosion prevention of a metal film is important is a stripping process using a resist stripper. When forming through-holes on metal wiring, it is necessary to form a hole by dry etching, and then remove and remove the resist residue and etching residue. Is an important issue. For this reason, it is widely practiced to add an anticorrosive to the resist stripping solution to prevent corrosion of metal wiring. As such anticorrosives, aromatic hydroxy compounds such as hydroxybenzoic acid, organic compounds containing a carboxyl group such as acetic acid, cunic acid, and succinic acid, and benzotriazole (BTA) have been used. Japanese Unexamined Patent Publication No. Hei 8-333495).

In addition, in the chemical mechanical polishing (CMP) process that is performed when copper is used as the wiring metal, not only is the quality of the wiring metal deteriorated due to corrosion, but also the corrosion prevention of the metal is required for process reasons. It becomes important. With wiring metal If copper is used, fine patterning by dry etching is difficult, so wiring is usually patterned by a process called the damascene method (Figure 3). In the damascene method, first, a wiring groove is formed in the insulating film 3 (FIG. 3 (a)), and then a non-metal film 4 is formed on the entire surface. Next, after a copper film 5 is formed on the entire surface so as to fill the wiring groove (FIG. 3 (b)), the copper film formed in a region other than the wiring groove by chemical mechanical polishing (hereinafter referred to as “CMP”). Remove 5 In this way, a copper wiring having a shape in which copper is embedded in the wiring groove is formed (FIGS. 3C and 3D). Here, corrosion prevention of copper is important because corrosive slurry is used in the CMP process, so that copper corrosion is likely to progress. In addition, in the CMP process, (i) generation of a discarding erosion, (ii) generation of a slit between a copper film and a barrier metal film, and (iii) a copper polishing pad polished by CMP. Problems specific to the CMP process, such as adhesion to wafers, occur, so it is important to prevent copper corrosion from the viewpoint of preventing these problems. Hereinafter, this point will be described.

Dating is a phenomenon in which the center of the surface of the copper film 5 is dented as shown in FIG. This is caused by the fact that the polishing rate of the copper film 5 is much higher than the polishing rate of the non-metal film 4. When such dicing occurs, various problems such as a decrease in the cross-sectional area of the wiring and a local increase in the resistance are caused. Erosion is a phenomenon in which the CMP progresses excessively in the dense wiring area, and the surface of the dense wiring area is dented as shown in Fig. 3 (d). When the erosion occurs, the wiring resistance increases, and the flatness of the substrate surface deteriorates, which causes a short circuit of the wiring. The slit between the copper film and the barrier metal film refers to a slit as shown in FIG. 4 generated in the CMP by a kind of battery effect. The occurrence of such a slit increases the wiring resistance and causes a subsequent film formation failure.

The adhesion of copper polished by CMP to wafers, etc. means that copper ions generated during CMP accumulate on the polishing pad and re-adhere on the A-side, deteriorating the flatness of the A-side. Or cause an electrical short circuit. This problem is described in, for example, JP-A-10-116804.

As mentioned above, CMP requires not only metal quality degradation due to corrosion but also metal corrosion protection for process reasons. In traditional CMP, mainly W

3 An anticorrosive was used from the viewpoint of preventing dishing and preventing copper from adhering to the polishing pad, and benzotriazole or a derivative thereof was used (Japanese Patent Application Laid-Open Nos. 8-83780 and 11-11). —2 3 8 7 0 9 Publication).

However, BTA and its derivatives are difficult to be decomposed by living organisms, and there is a problem that it is difficult to treat wastewater containing them. In recent years, as the demand for reducing environmental burden has increased, higher safety has also been required for chemical substances used in semiconductor manufacturing plants. Organic wastewater generated from semiconductor manufacturing plants is usually subjected to biological treatment (hereinafter referred to as “biological treatment”), decomposed, and released. However, for substances that cannot be treated by biological treatment, other It is desirable to treat by means or to replace with other biodegradable chemicals. The above-mentioned BTA and its derivatives are extremely difficult to decompose by biological treatment. For the above reasons, factories that use chemicals containing BTAs not only pose environmental risks to the treatment of their waste liquids and wastewater, but also have to rely on treatment methods other than biodegradation treatment, which are costly and laborious. It was not possible to get it.

On the other hand, as described above, in the field of the resist stripping solution, an aromatic hydroxy compound or an organic conjugate containing a ruboxyl group was sometimes used as an anticorrosive agent. Generally, it is more biodegradable than BTAs. However, since these are mainly for the purpose of preventing corrosion of wiring materials made of aluminum-copper alloy, they do not have sufficient anticorrosion action against easily corrosive metals such as copper, and are subject to severe conditions such as CMP. It was difficult to use it as an anticorrosive for use in steels.

As described above, the prior art relating to corrosion prevention in a semiconductor device manufacturing process has been described. As a prior art in a technical field different from the present invention, Japanese Patent Application Laid-Open No. 9-291381 discloses a water-soluble antibacterial agent. As examples of urea condensates, isocyanuric acid, hydantoin, uric acid, triscarboxymethyl isocyanuric acid, and triscarboxyethyl isocyanuric acid are exemplified. . However, this technology is aimed at preventing metal buckling during metal processing such as cutting, polishing, and plastic processing, and in the storage of such metal. It does not provide technology that takes into account the removal of residues that accumulate on the surface or advanced surface cleaning. In addition, the technology described in the above publication aims The problem to be solved is different from that of the present invention for the purpose of “corrosion prevention”. "Anti-corrosion" is to prevent the progress of metal oxidation, whereas "anti-corrosion" in the present invention is to prevent corrosion of the metal film formed on the semiconductor layer. Specifically, it is intended to prevent a metal such as copper from being dissolved by a resist stripping solution, various cleaning solutions, a CMP slurry, or the like, or from being altered by forming a complex or the like. In addition, the treatment with the P-matrix agent is usually performed in the air to form a protective layer made of a protective agent on an oxide film present on the metal surface, whereas the present invention provides "Corrosion protection" is to form a protective layer by applying an anticorrosive agent to a clean metal surface that has not been oxidized. Even if the surface of the metal is slightly oxidized (when the surface is slightly oxidized), the metal B-diameter formed on the semiconductor wafer has various problems such as increased resistance and poor adhesion to the film formed thereon. Problems arise. Therefore, the anticorrosive agent of the present invention forms a dense protective film on the surface of the metal film, substantially completely suppresses oxidation of the metal film, and dissolves the metal film in a resist stripping solution or various cleaning solutions. It is necessary to effectively prevent the formation of That is, “corrosion protection” in the present invention requires a higher level of metal film protection than protection. Furthermore, as will be described later, anticorrosives used for preventing corrosion of a metal film formed on a semiconductor wafer need to have various characteristics, unlike anticorrosives for general metal members. . As described above, in designing the anticorrosive agent of the present invention used in the manufacturing process of a semiconductor device, it is necessary to study from a viewpoint different from that of general metal. Disclosure of the invention

The present invention has been made in view of the above circumstances, has an excellent anticorrosion performance for effectively preventing corrosion of easily corrodable metals such as copper, has excellent product safety, and further has a decomposition treatment by living organisms. It is an object of the present invention to provide an anticorrosive agent that has good decomposability and that can be used.

In the development of anticorrosion agents, how to enhance the anticorrosion performance against metals has been an important technical issue.However, in addition to the anticorrosion performance, sufficient high safety and excellent biodegradability are provided. In order to do so, it is necessary to study from a different perspective. The present inventors have studied from such a viewpoint, and have found that a heterocyclic compound having a specific structure It has been found that the use of as an anticorrosion component can achieve both high anticorrosion performance, sufficiently high safety, and excellent biodegradability, and completed the present invention.

According to the present invention, there is provided an anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor wafer, which contains a heterocyclic compound having a six-membered ring containing a nitrogen atom as an anticorrosion component. An anticorrosive is provided.

Further, according to the present invention, there is provided an anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor wafer, wherein

-C (O H) = N—, or

One C O N H—

The present invention provides an anticorrosive comprising a heterocyclic compound having a 5- or 6-membered heterocyclic ring containing the following atomic group.

Further, according to the present invention, there is provided an anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor element, comprising purine or a derivative thereof as an anticorrosion component. Is provided.

Further, according to the present invention, there is provided an anticorrosion solution obtained by dissolving the anticorrosion agent in water or a water-soluble organic solvent.

Further, according to the present invention, there is provided an anticorrosion treatment solution for use in a semiconductor way, wherein the anticorrosion treatment solution is a corrosion-resistant treatment solution for a metal film formed thereon, the anticorrosion treatment solution comprising the anticorrosive agent. You.

Further, according to the present invention, there is provided a storage solution for storing a semiconductor wafer having a metal film formed on a surface thereof, wherein the storage solution contains the anticorrosive agent. Further, according to the present invention, there is provided a slurry for chemically and mechanically polishing a semiconductor wafer having a metal film formed on a surface thereof, the slurry containing the anticorrosive agent. A slurry is provided.

Further, according to the present invention, a metal film is formed on a semiconductor wafer, a part of the metal film is chemically and mechanically polished, and the surface of the semiconductor wafer is cleaned using a cleaning liquid. The present invention provides an anticorrosion treatment method comprising performing an anticorrosion treatment on the metal film by using the method.

The present invention uses a heterocyclic compound having a specific structure as described above as an anticorrosive Since it is used, a dense protective layer is formed on the surface of the metal film, and the surface of the metal film can be kept moderately hydrophobic, and exhibits excellent anticorrosion performance. In addition to being excellent in safety, it is possible to decompose by living organisms and easily perform wastewater treatment.

Since the anticorrosive in the present invention is used for the purpose of preventing the corrosion of a metal film formed on a semiconductor wafer, it is necessary to have various properties unlike the anticorrosive for general metal members.

First, in the semiconductor device manufacturing process, even if a part of the metal wiring is slightly damaged, it is often impossible to achieve the performance as designed, so that extremely high corrosion protection performance is required. In particular, in the manufacturing process of semiconductor devices, there are many steps using acid or alkali chemicals, such as etching, resist stripping, and cleaning, and in these steps, the dissolution and deterioration of the metal film are sufficiently suppressed. Need to be done. In addition, when the anticorrosive agent of the present invention is used by being added to a stripping solution such as a resist or a CMP slurry, it is required to exhibit a high anticorrosive action in the presence of other components.

Second, it is necessary not to damage the semiconductor substrate and various films formed thereon. In recent semiconductor device manufacturing processes, the miniaturization of elements has been further advanced, and even if the substrate or film constituting the semiconductor device is slightly damaged, fatal damage to the element performance will occur. May give.

Third, it is necessary that the post-corrosion treatment be not adversely affected. For example, if an anticorrosive is left on the surface of a metal film and an insulating film or other metal film is formed thereon, the device performance may be adversely affected, such as an increase in resistance and film peeling. Therefore, select an anticorrosion agent that does not adversely affect the element performance even if it remains, or select an anticorrosion agent that desorbs from the metal film surface at the stage after the anticorrosion treatment and before moving to the next process It is desirable to do so.

Fourth, since it is used in the process of manufacturing semiconductor devices, the amount of waste liquid is large, and it is particularly required that the treatment be performed safely, promptly and at low cost. Therefore, it is strongly required to be composed of bioprocessable components.

The anticorrosive of the present invention has the above properties. That is, the anticorrosive contained in the release agent composition of the present invention exhibits strong release performance even in the presence of other chemical substances. It does not damage the substrate or other films. In addition, the anticorrosive attached to the metal film is quickly eliminated by preheating for film formation. Furthermore, it is excellent in safety and biodegradability. Therefore, the configuration is particularly suitable for preventing corrosion of the metal film formed on the semiconductor wafer. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a process sectional view for explaining a copper wiring forming process by a damascene method.

FIG. 2 is a schematic configuration diagram of a chemical mechanical polishing apparatus.

3, der process sectional view for explaining a process of forming copper wiring by a damascene process _Q

FIG. 4 is a diagram showing a cross section of a copper wiring in which dishing and slit have occurred. FIG. 5 is a view for explaining a step after CMP.

FIG. 6 is a view for explaining a process after the CMP.

FIG. 7 is a diagram for explaining a process using the anticorrosive agent according to the present invention. FIG. 8 is a diagram for explaining a process using the anticorrosive agent according to the present invention. FIG. 9 is a process cross-sectional view for explaining the through-hole forming process.

FIG. 10 is a process cross-sectional view for explaining the through-hole forming process. FIG. 11 is a graph showing the effect of uric acid concentration on the etching rate of a copper film.

FIG. 12 is a diagram showing a change in the electron migration lifetime due to the difference in the anticorrosion treatment. BEST MODE FOR CARRYING OUT THE INVENTION

The component (a) in the present invention may contain a heterocyclic compound having a six-membered ring containing a nitrogen atom in the molecule. Such a heterocyclic compound exhibits a good anticorrosive action and a good biodegradability due to the chelating action of the nitrogen atom in the complex.

Also, as the component (a), One C (OH) two N—, or

One CON H—

When a heterocyclic compound having a 5- or 6-membered heterocyclic ring containing the following atomic group is used, particularly good anticorrosive action and biodegradability are exhibited. The reason for this is not necessarily clear, but is presumed as follows.

In the above heterocyclic compound, each atom of C, N, 0, and H is on the same plane,

-C (OH) = N— (amide unit) and

It is tautomeric with -C0NH- (iminohydrin unit). This is known as lacta muractim tautomerism (formula below).

Lactam type Lactim type In the above formula, a conjugate system spreads over each of the N, C, and 0 atoms, and electrons are delocalized in this region. The electrons in this conjugated system are liable to interact with the free orbitals on the metal surface, and are considered to form stable chelate bonds.

In addition, since the above-mentioned atomic group is contained in the cyclic portion of the 5- or 6-membered heterocyclic ring, the steric hindrance is low, and the above-mentioned atomic group is easily accessible to metal atoms. Conceivable.

It is presumed that the heterocyclic compound having a 5- or 6-membered heterocyclic ring containing an amide unit or an iminohydrin unit in the molecule has a remarkable anticorrosive action for the above-mentioned reason.

The reason for the good biodegradability is presumed to be related to the high biocompatibility of the amide bond.

As specific examples of the heterocyclic compound in the present invention,

Purine, 6-Aminopurine, 2-Amino-1-6-isoquinopurine, 6-Furfurylaminopurine, 2,6- (1H.3H) -Purinedion, 2-Amino-1-6-hydroxy-18-Mercaptopurine, Aloprinol , Uric acid, power ricetin, zeatin, Purines and derivatives thereof such as guanine, xanthine, hypoxanthine, adenine, theopherin, caffeine, and theopromine;

Azaguanine such as 8-azaguanine and derivatives thereof;

Pteridine, pterin such as pteridine, pterin, 2-amino-4,6-dihydroxypteridine, 2-amino-1,4,7-dihydroxypteridine, 2-amino-4,6,7-trihydroxypteridine, and derivatives thereof;

Cyanuric acid, isocyanuric acid, triscarboxymethylcyanuric acid, triscarboxycylcyanuric acid, triscarboxymethylisocyanuric acid, triscarboxyxyl isocyanuric acid, etc. Conductor;

Hydantoin, allantoin and derivatives thereof, such as hydantoin, dimethylhydantoin, and allantoin (5-ureidohydantoin);

Barbituric acids and their derivatives;

Nicotinic acid such as isonicotinic acid and citrazinic acid and derivatives thereof; and the like, and these can be used alone or in combination of two or more. Of the above, purine and its derivatives, and nicotinic acid and their derivatives are preferred and used. It is not only excellent in biodegradability, but also has an excellent anticorrosion effect on metals such as copper.

Of the above, pudding and its derivatives, in particular, exhibit an excellent anticorrosion effect, do not damage the semiconductor substrate and various films formed thereon, and do not adversely affect the processes after the peeling treatment. Therefore, it is preferably used. Among them, the compound represented by the following general formula (1), particularly uric acid, is a highly safe substance that is widely distributed in nature, is particularly excellent in biodegradability, and is extremely excellent in anticorrosion. Used.

0)

(,,. Α ₂ and Α ₃ are each independently a hydrogen atom, a hydroxyl group, a carbon atom. Represents a alkyl group or an amino group. )

In the above formula, it is desirable that at least one of A ₂ and A ₃ is a hydroxyl group _(in this case, a structure having an amide bond in the heterocyclic ring is obtained, and the anticorrosive action and the biodegradability are particularly improved.

It is known that, in the compound having an amide unit in the cyclic portion, the amide unit is converted into an iminohydrin unit and forms a lactam type and a lactim type as shown in the following formula. For example, uric acid has the following resonance structure.

The anticorrosive of the present invention can be used by dispersing it in water or a water-soluble organic solvent described below. In this case, if the alkanolamines are further added, the solubility of the anticorrosive can be improved. If an alkanolamine having good biodegradability is selected, an anticorrosive solution having particularly excellent safety and biodegradability can be obtained.

Specific examples of alkanolamines include monoethanolamine, jetanolamine, N-ethylaminoethanol, N-methylaminoethanol, N-methylethylethanol, dimethylaminoethanol, 2- (2-aminoethoxyamine). ) Ethanol, 1-amino-12-propanol, triethanolamine, monopropanolamine, dibutanolamine and the like are exemplified. Of these, monoethanolamine and N-methylaminoethanol are particularly preferred. These compounds may be used alone or in combination of two or more.

The mixing ratio of the anticorrosive component (hereinafter, referred to as component (a)) and the alkanolamines (hereinafter, referred to as component (b)) in the anticorrosive agent can be set arbitrarily. For example, (a) ) The amount of the component (b) relative to 100% by mass of the component is preferably 0.1 to 1000% by mass, and more preferably 1 to 100% by mass. With such a mixing ratio, it is possible to exhibit higher anticorrosion performance.

The anticorrosive of the present invention, when used for anticorrosion of copper or a copper alloy containing copper as a main component, Especially effective. A copper alloy containing copper as a main component is an alloy containing 90% by mass or more of copper, such as Mg, Sc, Zr, Hf, Nb, Ta, Cr, or Mo. A copper alloy containing a different element. These metals improve the high-speed operability of the device with low resistance, but are liable to cause corrosion such as dissolution and alteration by a chemical solution, so that the application effects of the present invention are remarkable.

The anticorrosion solution according to the present invention is obtained by dissolving the anticorrosion agent in water and / or a water-soluble organic solvent.

Examples of the water-soluble organic solvent include sulfoxides such as dimethyl sulfoxide; sulfones such as dimethyl sulfone, getyl sulfone, bis (2-hydroxyethyl) sulfone and tetramethylene sulfone; N, N-dimethylformamide; Amides such as N-methylformamide, N, N-dimethylacetamide, N-methylacetamide, N, N-getylacetamide; N-methyl-2-pyrrolidone, N-ethyl-12-pyrrolidone Lactams such as N-propyl-12-pyrrolidone, N-hydroxymethyl-12-pyrrolidone, N-hydroxyethyl-12-pyridone; 1,3-dimethyl-2-imidazolidinone; Imidazolidinones such as, 3-Jethyl-2-imidazolidinone and 1,3-diisopropyl-l2-imidazolidinone; r-butyrolactone, ά- Lactones such as Roh ¹ Reroraku Bokun; ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol mono-et Chirueteru, ethylene glycol mono-Petit ether, ethylene glycol mono methyl ether § cetearyl Ichiboku, ethylene glycol monomethyl E chill ether § cetearyl one And polyvalent alcohols such as diethylene glycol, diethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and diethylene glycol monobutyl ether, and derivatives thereof. These may be used alone or in combination of two or more.

Alkanolamines (component (b)) may be added to the anticorrosive liquid according to the present invention. By doing so, the solubility of the anticorrosion component (component (a)) can be increased, and the anticorrosion effect is more remarkably exhibited. The concentration of the components (a) and (b) in the anticorrosive solution according to the present invention is appropriately set according to the intended use and purpose. For example, the following is preferable. That is, the amount of the component (a) is W

12 The lower limit is preferably 0.0001% by mass, particularly preferably 0.01% by mass. The upper limit is not particularly limited, but is, for example, about 20% by mass due to solubility. On the other hand, the upper limit of the amount of component (b) is preferably 20% by mass / ₀ , particularly preferably 10% by mass / ₀ . Further, the lower limit is preferably 0.0001% by mass, and particularly preferably 0.001% by mass. With such a blending amount, the anticorrosion performance can be further improved.

The anticorrosive agent of the present invention is used for anticorrosion of metal films (particularly copper films) formed on semiconductor wafers. For example, anticorrosion treatment solutions used for CMP slurry or after CMP, and storage of wafers liquid, or, _c present invention can be applied to the stripping solution of Regis Bok, etc., a metal film, particularly when applied to a semiconductor © E eighteen of CM P processes with an exposed surface of the copper film, more effective It is. In the CMP process, the metal corrosive slurry is used, so that the corrosion of the metal is apt to progress, (i) dishing erosion occurs, and (ii) the slit between the metal film and the barrier metal film. And (iii) adhesion of the metal polished by CMP to the polishing pad A8. According to the anticorrosive agent of the present invention, a dense protective layer is formed on the surface of the metal film, and the surface of the metal film is maintained at an appropriate hydrophobicity, so that the above problem can be effectively resolved. Hereinafter, the application of the anticorrosive agent according to the present invention to the CMP process will be described.

The steel wiring forming process using CMP is performed through the steps shown in FIG. First, as shown in FIG. 1 (a), a silicon oxide film 1, a silicon nitride film 2 and a silicon oxide film 3 are formed in this order on a silicon wafer (not shown), and then dry etching is performed. A plurality of wiring grooves patterned into a predetermined shape are formed. Next, as shown in FIG. 1 (b), a barrier metal film 4 is deposited on the entire surface by a sputtering method. As the material of Roh ¹ barrier metal film, Ta, TaN, T i, Ding i N, W, WN, can be used WS i N, etc., the thickness is usually about 10 to 100 nm. Subsequently, a copper film 5 is formed on the barrier metal film 4 (FIG. 1 (b)). The copper film 5 can be formed by a plating method, a CVD method, a sputtering method, or the like. Next, the surface of the copper film 5 is polished by the CMP method. CMP usually uses a slurry consisting mainly of an oxidizing agent and abrasive grains, and etches the copper surface by the chemical action of the oxidizing agent. At the same time, the surface of the oxide film is mechanically removed by abrasive grains. By adding the anticorrosive agent of the present invention to the slurry for CMP, corrosion of copper during CMP can be prevented, and dating can be prevented by suppressing the polishing rate of copper. Further, although a large amount of waste liquid is generated in the CMP process, the anticorrosive agent of the present invention has good biodegradability, so that waste liquid treatment becomes easy.

CMP is performed until the barrier metal film 4 is completely removed as shown in FIG. In this step, a single slurry for CMP may be used, but two or more slurries may be used from the viewpoint of preventing dicing and erosion. Two types of slurries for polishing can be used. When the anticorrosive agent of the present invention is applied to a slurry for CMP, it may be used in any stage of the slurry.However, as shown in Fig. It is effective. This is because the effect of preventing corrosion of the copper film 5 constituting the wiring portion and the effect of suppressing dating / erosion are further remarkable.

CMP ends when the barrier metal film 4 is removed and the torque changes (FIG. 1 (d)). Thereafter, post-cleaning is performed as necessary, and then rinsing is performed with a rinsing liquid containing pure water as a main component. Then, the copper wiring forming process is completed.

CMP can be performed using, for example, a chemical mechanical polishing apparatus as shown in FIG. The wafer 21 on which an insulating film, a copper-based metal film, or the like is formed is placed on a wafer carrier 22 of a spindle. The surface of the wafer 21 is brought into contact with a polishing pad 24 stuck on a rotating plate (platen) 23, and the slurry for CMP is supplied to the surface of the polishing pad 24 from a slurry supply port 25 for CMP. While polishing, both wafer 21 and polishing pad 24 are rotated. If necessary, the pad conditioner 26 is brought into contact with the surface of the polishing pad 24 to condition the polishing pad surface. The slurry for CMP may be supplied from the rotating plate 23 to the surface of the polishing pad 24.

The present invention can be applied in post-processing after CMP. Figure 5 shows an example of post-processing after CMP. After CMP, once store the wafer in the storage solution, perform post-CMP cleaning to remove abrasive particles and the like. Then, if necessary, add an anticorrosive Perform anti-corrosion treatment, and finally rinse with a rinsing liquid containing pure water as a main component. Here, if the anticorrosive agent according to the present invention is added to the above-mentioned storage solution, anticorrosion treatment solution, and rinsing solution, there is no risk of waste liquid treatment, and there is a risk of working on the safety of chemical substances. Therefore, it is possible to suitably prevent corrosion of the copper film formed on the substrate.

If CMP and CMP post-processing are inlined, the process is as shown in Figure 6. In this case, it is effective to use the anticorrosion agent according to the present invention in the anticorrosion treatment shown in the figure.

Hereinafter, preferred embodiments of the slurry for chemical mechanical polishing, the storage solution, and the anticorrosion solution according to the present invention will be described.

The slurry for chemical mechanical polishing of the present invention contains the anticorrosive agent according to the present invention described above. The content of the anticorrosive is preferably 0.01% by mass or more, more preferably 0.1% by mass or more based on the total amount of the slurry, from the viewpoint of obtaining a sufficient anticorrosive effect. From the viewpoint of adjusting the polishing rate to an appropriate value, the content is preferably 30% by mass or less, more preferably 20% by mass or less. If the content is too large, the anticorrosion effect becomes too large, and the polishing rate of copper is too low, so that it may take time for CMP.

The slurry for chemical mechanical polishing of the present invention preferably contains a polishing material, an oxidizing agent, and water in addition to the above anticorrosive agent, and may further contain an organic acid or the like as appropriate. .

Examples of abrasives include alumina such as mono-alumina, 0-alumina, and 5-alumina, silica such as fumed silica and colloidal silica, titania, zirconia, germania, ceria, and abrasive grains of these metal oxides. One or a mixture of two or more selected from the group can be used.

The content of the abrasive in the CMP slurry is appropriately set in consideration of the polishing efficiency, the polishing accuracy, and the like, and is preferably 0.1 to 50% by mass, and more preferably <2%, based on the total amount of the slurry composition. To 30% by mass.

The oxidizing agent can be appropriately selected from known water-soluble oxidizing agents in consideration of the type of the conductive metal film, polishing accuracy, and polishing efficiency. For example, hydrogen peroxide (H ₂ 〇 ₂ ), Na ₂ O ₂ , Ba ₂ O ₂ , (C ₆ H ₅ C) ₂ O _2, etc., do not cause heavy metal ion contamination. Substances, hypochlorous acid (HC 10), perchloric acid, Examples include nitric acid, ozone water, and organic peroxides such as peracetic acid and nitrobenzene. Among them, it does not contain a metal component, not generate a harmful byproduct H ₂ 0 ₂ is preferred arbitrariness. The amount of the oxidizing agent is preferably at least 0.01% by mass, more preferably at least 0.05% by mass, based on the total amount of the CMP slurry, from the viewpoint of obtaining a sufficient effect of addition. From the viewpoint of suppressing dating and adjusting the polishing rate to an appropriate level, the amount is preferably 15% by mass or less, more preferably 10% by mass or less. When a oxidizing agent that deteriorates relatively slowly over time, such as hydrogen peroxide, is used, a solution containing an oxidizing agent having a predetermined concentration and a solution containing an abrasive are separately adjusted, and immediately before use. May be mixed.

The organic acid is added to promote the oxidation of the oxidizing agent and perform stable polishing. As the organic acid, one having a function as a proton donor is used, and diamino carboxylic acid is preferably used.

Specific examples of carboxylic acids include citric acid, formic acid, acetic acid, propyl acetic acid, butyric acid, valeric acid, acrylic acid, lactic acid, succinic acid, nicotinic acid, oxalic acid, malonic acid, tartaric acid, malic acid, Examples include glutaric acid, cunic acid, maleic acid, and salts thereof. '

Specific examples of amino acids include, for example, L-glucamic acid, D-glucamic acid, L-glucamic acid monohydrochloride, L-glucamic acid sodium monohydrate, L-glutamine, glutathione, glycylglycine, DL-alanine, L-alanine, -alanine, D-alanine, Ύ-peranine, 7 "-aminobutyric acid, etc.-aminocaproic acid, L-arginine monohydrochloride Salt, L-aspartic acid, L-aspartic acid monohydrate, L-aspartic acid potassium, L-aspartate calcium trihydrate, D-aspartic acid, L-titrulline, L-tryptophan, L-threonine, L-arginine, glycine, L-cystine, L-cystine, L-cystine hydrochloride [7] hydrate, L-proximal xyproline, shi-isoloucine, L-leucine, L-lysine monohydrochloride, DL-methiculo Nin, L-methyin, L-glutinin hydrochloride, L-Hue Ruaranin, D- phenylglycine, L - proline, L- serine, L- Ji port Shin, L - such as phosphorus and the like.

The content of the organic acid is preferably at least 0.01% by mass, more preferably at least 0.05% by mass, based on the total amount of the slurry for CMP, from the viewpoint of obtaining a sufficient effect of addition as a proton donor. In addition, it is important to control the dicing and adjust the polishing rate to an appropriate level. Therefore, the content is preferably 5% by mass or less, more preferably 3% by mass or less.

The CMP slurry of the present invention may contain various additives such as a dispersant, a buffer, a viscosity modifier and the like, which are widely and generally added to the CMP slurry, as long as the properties are not impaired. .

The slurry for CMP according to the present invention can be produced by using a general method for producing a free abrasive polishing slurry composition. That is, an appropriate amount of abrasive particles is mixed with the dispersion medium. If necessary, mix the appropriate amount of protective agent. In this state, air is strongly adsorbed on the surface of the abrasive particles, so that the abrasive particles have poor wettability and exist in an aggregated state. Therefore, in order to make the aggregated abrasive particles into primary particles, the particles are dispersed. In the dispersing step, a general dispersing method and dispersing apparatus can be used. Specifically, it can be carried out by a known method using, for example, an ultrasonic disperser, various types of bead mill dispersers, kneaders, ball mills and the like.

The storage solution of the present invention is preferably an aqueous solution in which the anticorrosive agent of the present invention is dissolved in water. The lower limit of the concentration of the anticorrosive agent relative to the whole storage solution is preferably <0.01% by mass, more preferably 0.01% by mass or more. If the concentration of the anticorrosive is too low, a sufficient anticorrosive effect may not be obtained. Although there is no particular upper limit on the concentration of the anticorrosive agent, a sufficient anticorrosive effect can be obtained, for example, at 20% by mass or less. However, in some cases, the anticorrosive agent of the present invention does not have sufficient anticorrosive properties simply by adding it to water.c Therefore, by adding alkanolamine and adjusting the pH to alkaline. Therefore, it is necessary to increase the solubility of purines and purine derivatives, and adjust the concentration to obtain sufficient anticorrosion performance.

There is no particular limitation on the environment in which the semiconductor wafer is stored in the storage solution. For example, for storage after CMP, it is common to store in the same environment where the CMP equipment is installed. The storage solution according to the present invention can be used not only for storage after CMP but also for various processes.

The anticorrosion treatment liquid of the present invention is preferably an aqueous solution in which the anticorrosive agent of the present invention is dissolved in water, like the above-mentioned storage solution. Other additives, water-soluble organic solvents, and the like may be appropriately added to this aqueous solution. The lower limit of the concentration of the anticorrosive in the whole storage solution is preferably 0.001% by mass, more preferably 0.01% by mass or more. Anticorrosive concentration If it is too low, a sufficient anticorrosion effect may not be obtained. Although there is no particular upper limit on the concentration of the anticorrosive, a sufficient anticorrosive effect can be obtained, for example, at 20 mass% or less. The anticorrosion treatment solution of the present invention can be applied to the anticorrosion treatment step shown in FIG. 5 or to a pure water rinsing step. In this case, the anticorrosion treatment liquid preferably has a configuration in which the anticorrosion agent of the present invention is dissolved in pure water in the above concentration range. The anticorrosion treatment solution of the present invention can be used not only in the anticorrosion treatment after CMP but also in various steps.

The above-mentioned slurry for chemical mechanical polishing, anticorrosion treatment solution, and storage solution are used for treating semiconductors A having a metal film-exposed surface, and the metal film contains a copper film or copper as a main component. The effect of the present invention is more remarkably exhibited when the copper alloy film is

The storage solution and anticorrosion solution of the present invention may optionally contain additives, organic solvents and the like. For example, an acid or base for adjusting the pH may be added to improve the solubility of the anticorrosive, and a water-soluble organic compound miscible with water or other compounding components may be added to further improve the anticorrosion performance. Solvents can be used.

The anticorrosive according to the present invention can also be applied to a stripping solution such as a resist. In this case, it is preferable to use a stripping solution containing alkanolamine or ammonium hydrofluoride as a stripping component and further containing water.

Examples of the alkanoamine include monoethanolamine, jetano-lamine, N-ethylaminoethanol, N-methylaminoethanol, N-methylgenolamine, dimethylaminoethanol, and 2- (2-aminoethylamine. (Toxi) Ethanol, 1-amino-2-propanol, triethanolamine, monopropanolamine, dibutanolamine and the like are exemplified. Of these, monoethanolamine and N-methylaminoethanol are particularly preferred.

When removing residues and the like that are difficult to remove with the above-mentioned amine-based release component, hydrofluoric acid salt can be used as the release component. Specifically, fluoride ammonium or the like is preferably used. When hydrofluoric acid is used, deposits and the like adhering to the resist side wall can be removed.

The upper limit of the release component in the release solution is preferably 95% by mass, and particularly preferably 85% by mass. The lower limit is preferably 1% by mass, and particularly preferably 10% by mass. Such a distribution By using the total amount, the resist film and the etching residue can be more efficiently removed while maintaining good anticorrosion performance.

The upper limit of the proportion of water in the stripping solution is preferably 90% by mass, particularly 80% by mass. / ₀ is preferred. The lower limit is preferably 1% by mass, and particularly preferably 5% by mass. By controlling the amount as described above, the function of the peeling component alkanolamine is sufficiently exhibited, and the peeling performance and the anticorrosion performance are further improved.

The stripping solution using the anticorrosive of the present invention may contain a water-soluble organic solvent. As the water-soluble organic solvent, the same ones as described above can be used. The upper limit of the amount of the water-soluble raw organic solvent is preferably 80% by mass, particularly preferably 70% by mass. The lower limit is preferably 5% by mass, particularly preferably 10% by mass. By using such an amount, the balance between the peeling performance and the anticorrosion performance becomes better.

The above-mentioned stripping liquid is used to turn an unnecessary object on the semiconductor substrate into an object to be stripped. The unnecessary substances on the semiconductor substrate refer to various unnecessary substances generated during a semiconductor device manufacturing process, and include a resist film, an etching residue after dry etching, and a chemically modified resist film. In particular, it is more effective when the object to be peeled is a resist film and / or an etching residue on the semiconductor substrate including the metal film exposed surface. Further, when the metal film is a copper film, the anticorrosive action of the anticorrosive agent of the present invention is more effectively exhibited.o

The above-mentioned stripping solution can be used for stripping various resists, and should be applied to KrF resists made of aromatic compounds and ArF resists such as alicyclic acryl polymers. Can be. For example, (i) a positive resist containing a naphthoquinonediazide compound and a novolak resin, (ii) a compound that generates an acid upon exposure, a compound that is decomposed by an acid to increase the solubility in an aqueous solution of an aqueous solution, and (Iiii) a compound capable of generating an acid upon exposure, and a positive resist containing a soluble resin having a group which is decomposed by the acid and increases the solubility in an aqueous solution of an aqueous solution. It can be used for a resist, (iv) a compound which generates an acid by light, a cross-linking agent and a negative resist containing a soluble resin. Next, as an application example of the stripping solution using the anticorrosive agent of the present invention,

An example in which an interlayer connection plug on a copper wiring is formed by a process. First, as shown in Fig. 9 (a), a silicon oxide film 1, a silicon nitride film 2, and a silicon oxide film 3 are formed on a semiconductor substrate (not shown) on which elements such as transistors are formed. A copper interconnect composed of a barrier metal film 4 and a copper film 5 is formed by a known damascene process using chemical polishing (CMP), and a silicon nitride film 6 having a thickness of about 50 to 100 nm is formed thereon. Then, an interlayer insulating film (silicon oxide film or low dielectric constant film) 7 having a thickness of about 600 to 1 OOO nm is formed. The thickness of the copper film 5 is arbitrarily selected, but is preferably, for example, 350 nm or less from the viewpoint of reducing the parasitic capacitance between adjacent wirings. When the thickness of the copper wiring is reduced, the thickness of the corroded layer relative to the entire copper wiring layer becomes relatively large, and an increase in wiring resistance due to corrosion of the copper surface becomes a particular problem. The use of the stripping solution can reduce the film thickness while solving such a problem. In the present embodiment, the thickness of the silicon nitride film 6 is set to about 50 to 100 nm, but it may be made thicker to enhance the function as an etching stopper film.

Next, a resist film 8 patterned into a predetermined shape is provided on the interlayer insulating film 7 (FIG. 9 (b)).

Next, the interlayer insulating film 7 is dry-etched using the resist film 8 as a mask until the silicon nitride film 6 is exposed, thereby forming a through hole 10 (FIG. 9 (c)). At this time, the etching residue 11 adheres to the inner wall of the through hole 10. The opening diameter of the through hole is, for example, about 0.2 m. As an etching gas, it is preferable to use a gas that can etch an interlayer insulating film faster than a silicon nitride film. Here, the silicon nitride film 6 also has a function of preventing diffusion of copper and a function as an etching stop film. However, as shown in FIG. 9 (c), the silicon nitride film 6 is controlled on the silicon nitride film 6. Sometimes dry etching cannot be stopped well. This is for the following reasons. In the process as in the present embodiment, various through holes are generally formed on the semiconductor wafer. However, etching proceeds slowly in a hole with a small opening diameter due to the micro-loading effect. For this reason, it is necessary to provide a certain amount of etching time for the etching for forming the through-hole, and as a result, the silicon nitride film 6 is etched in some of the through-holes and the copper film 5 The part will be exposed. Also, for example, on the copper film 5 When a concave portion called dishing occurs on the surface, a thin film portion of the silicon nitride film 6 is generated, and the silicon nitride film 6 is etched at this portion, and a part of the copper film 5 may be exposed (see FIG. 9 (c)). )). If the silicon nitride film 6 is formed thick in the step shown in FIG. 9 (a), it is possible to prevent the copper film 5 from being exposed.However, in this case, the capacitance between adjacent copper wirings increases, and the semiconductor element The disadvantage is that the high-speed operation is hindered.

After the etching is completed, a part of the resist film 8 is removed by oxygen plasma pacing, and then a stripping treatment is performed using a stripping solution containing the anticorrosive agent of the present invention. By this stripping treatment, the resist film etching residue 11 that could not be removed by asshing is removed. As described above, since the copper film 5 is exposed in at least some of the through holes after etching, the stripping solution needs to have anticorrosion performance against copper, but the stripping using the anticorrosive of the present invention is required. FIG. 10 (a) shows a state in which the resist film and the etching residue 11 can be effectively removed without damaging the copper film 5 by using the liquid. C The stripping process is completed.

Then, the etching of the silicon nitride film 6 is performed by changing the above-mentioned etching and etching gas. At this time, the etching residue 12 adheres to the inner wall of the through hole 10 (FIG. 10 (b)). In order to strip and remove the etching residue 12, a stripping treatment is performed again using the stripping solution described above. At the stage of performing the stripping process, the copper film 5 is exposed at the bottom of the through hole 10. However, by using the stripping solution containing the anticorrosive agent of the present invention, the copper film 5 is etched without damaging the copper film 5. The residue 12 can be removed (Fig. 10 (c)).

After that, a barrier metal film 14 and a tungsten film 15 in which Ti and TiN are stacked in this order inside the through hole are formed, and then the interlayer connection plug can be formed by planarization by CMP. (Figure 10 (d)).

Hereinafter, the present invention will be described in more detail with reference to examples. The amount of each component is based on the total amount of the anticorrosive solution and the stripping solution unless otherwise specified.

Example 1

This embodiment is an example in which the anticorrosive agent according to the present invention is applied to anticorrosion treatment after CMP. Hereinafter, an outline of the process performed in the present embodiment will be described with reference to FIGS. First, a Cu—CMP process 70 was performed (FIG. 7). The state corresponding to this step is shown in FIGS. 8 (a) and 8 (b). First, as shown in FIG. 8 (a), a silicon nitride film 80 and a silicon oxide film 82 were formed in this order on a silicon wafer, and then patterned into a predetermined shape by dry etching. A plurality of wiring grooves were formed. Next, after a barrier metal film 84 of TaN was deposited on the entire surface by a sputtering method, a seed Cu 85 and a plating Cu 86 were formed. Subsequently, the wafer surface was polished by the CMP method to form a copper wiring as shown in FIG. 8 (b).

Next, the following steps were performed in order to remove particles such as polishing abrasive grains and polishing debris, metal, and slurry attached to the surface of the semiconductor A8. First, the scrub cleaning step 72 was performed _c, that is, the brush was moved while applying a cleaning liquid composed of electrolytic ionized water to the rotating brush to remove particle contamination. Next, a spin cleaning step 74 was performed. In this process, an aqueous solution of oxalic acid was sprayed as a cleaning solution while rotating the semiconductor wafer to remove metal contamination, that is, copper oxide on the surface, and rinsed with pure water.

Next, an anticorrosion treatment step 75 was performed. This step is performed continuously after the spin cleaning step 74 so that the wafer surface does not come into contact with air. That is, the anticorrosion treatment is performed by spraying the anticorrosion treatment liquid without drying the surface of the wafer. As a result, oxidation of the metal film (copper film) on the wafer surface can be prevented, and an anticorrosive can be attached to a clean metal surface that has not been oxidized. In addition, the anticorrosion treatment was performed by spraying the treatment liquid onto the surface of the phenol while rotating the phenol at a predetermined number of rotations, similarly to the spin cleaning.

In this embodiment, anticorrosive treating solution used _c using an anticorrosive treatment liquid containing an anticorrosive agent of the present invention in anticorrosion treatment step 7 5 has the following composition.

Uric acid 0.05 mass%

N-methylaminoethanol 0.01% by mass

Water

The anticorrosion solution was sprayed on the wafer surface at a flow rate of 1 liter / min for 10 seconds while rotating the semiconductor wafer to prevent corrosion of the Cu film.

Thereafter, in a spin rinse-drying step 76, the substrate was rinsed with pure water for 15 seconds, and then dried. Next, in a film forming step 78 (FIG. 7), a silicon nitride film 88 was formed as shown in FIG. 8C, and a silicon oxide film 89 was formed thereon. After that, an upper layer wiring was formed to complete the semiconductor device. The obtained semiconductor device showed the designed performance. Example 2

After forming a copper plating film on the entire surface of the silicon wafer, Cu-CMP 70, scrub cleaning 72, spin cleaning 74, anticorrosion treatment 75, and spinning according to the procedure shown in Fig. 7. A sample was prepared by sequentially performing the following steps: sensing + drying 76 and forming a Si ₃ N ₄ film 78. The anticorrosion properties of the obtained samples were evaluated by measuring the adhesion. The scrub cleaning step 72 and the spin cleaning step 74 were performed in the same manner as in Example 1. In the anticorrosion treatment 75, 10 types of samples were prepared using the following 10 types of anticorrosion treatment solutions.

table 1

After the anti-corrosion treatment, it was left in the air for a predetermined number of days, and then silicon nitride (50 nm in thickness) was formed thereon by CVD. The number of days left unattended was 0 days (immediately), 1 day, and 3 days.

For samples 1 to 10 prepared as described above, the adhesion at the Cu / silicon nitride film interface was evaluated to evaluate the degree of deterioration of the Cu surface. The evaluation was performed by laying out lines in a grid pattern at a pitch of 1 mm on the silicon nitride film, then attaching an adhesive tape on the silicon nitride film, peeling it off, and peeling it out of the 100 grids. This was done by counting the number of grids. Excessive peeling <If the interface adhesion is poor, the Cu surface It is considered that the corrosion is progressing. Table 2 shows the evaluation results.

Table 2

From the above results, it was confirmed that by using the anticorrosive agent according to the present invention, corrosion on the Cu surface was effectively suppressed and the adhesion at the Cu / silicon nitride film interface was improved.

Example 3

Form a damascene copper interconnect of 0.28〃 (71, thickness 3500171 and length 100〃 m) in the interlayer insulating film on the silicon substrate.

The copper wiring was formed by forming a copper film by plating and then performing CMP. Next, steps from scrub cleaning 72 to interlayer film formation 79 were performed according to the procedure shown in FIG. Except for the composition of the anticorrosion treatment solution, the same procedure was performed as in Example 1. Next, holes were formed in the Si ₃ N ₄ film and interlayer film, a plug metal was buried inside, and a pad was formed to connect to this plug.Conducting portions were formed at both ends of the wiring. .

In the above anticorrosion treatment step 75, an anticorrosion solution having the following composition was used. W

25 Table 3

A plurality of samples were prepared for each experiment No., and a current was continuously applied between the pads at both ends of the wiring of each sample, and the electron migration life time until the wiring was disconnected was measured. Figure 12 shows the evaluation results. Those treated with uric acid showed the same lifetime as those treated with BTA.

Example 4

The biodegradability of the test substances shown in Table 3 was evaluated by a biodegradability test method based on the MITI method. Activated sludge was inoculated with the test substance in an inorganic medium so that the concentration of the test substance became 1 OOmgZl.], Cultured at 25 ° C, and the oxygen consumption was measured using a closed system oxygen consumption measuring device. In addition, the residual amount of the test substance was measured, the decomposition rate was determined from the oxygen consumption, and the biodegradability was determined according to the following evaluation criteria.

◎… Decomposition rate is 60% or more

〇… Decomposition rate is 40% or more and less than 60%

△ ·-'Decomposition rate is 10% or more and less than 40%

X: Decomposition rate is less than 10%

Table 4 shows the evaluation results.

Table 4

N M A N—Methylaminoethanol

M E A Monoethanolamine

B T A Benzotriazole

Example 5

The release agent composition according to the present invention was applied to a process of forming a through hole on a copper wiring, and the releasability and corrosion resistance were evaluated.

The samples to be evaluated were prepared according to the same processes as those shown in Figs. 9 to 10 (c). First, copper wiring is formed on the silicon wafer, and then a 90-nm-thick silicon nitride film and a 900-nm-thick interlayer insulating film (low-k film such as HSQ and MSQ) are formed on top of it. did. Next, a positive resist film was applied by a shiner to form a resist film. As the resist film material, PEX4 (manufactured by Tokyo Ohka Kogyo Co., Ltd.), which is a positive resist material for KrF, was used. The resist film was exposed through a mask pattern, and developed using an aqueous solution of tetramethylammonium hydroxide to obtain a resist pattern.

Using this resist film as a mask, the interlayer insulating film was dry-etched until the silicon nitride film was exposed to form a through hole having an opening diameter of 0.2 μm. As an etching gas, a full-year carbon-based gas was used. After the etching was completed, a part of the resist film was removed by oxygen plasma ashes, and then a release treatment was performed using a release agent composition shown in Table 5.1 of NO.

Next, the etching gas was changed and the silicon nitride film was etched to expose the copper wiring at the bottom of the through hole. The etching residue generated by this etching is For removal, the same release agent composition (N 0.1 in Table 5) as used in the above-described release treatment was used, and the release treatment was performed again.

The same treatment was performed using the release agent composition of No. 2-17 in Table 5, and a total of 17 kinds of samples were prepared.

After the wafer treated as described above is rinsed with pure water, the cross section is observed with a scanning electron microscope (SEM). 1) Separation of resist film and etching residue and 2) Copper film The anti-corrosion properties of the samples were evaluated. The evaluation criteria are as follows. C (peelability)

Observe the residual state of the resist film and the etching residue, and evaluate in the following four steps.

A: No residual was observed.

ο · · 'There was almost no residual.

Δ: The remaining amount is small.

X: The remaining amount is large.

(Anticorrosion)

The state of corrosion of the copper film surface was observed and evaluated according to the following four levels.

O: Slight corrosion of the copper film was observed.

△ · '· Copper film corrosion was observed.

X: The corrosion of the copper film was remarkable.

(H SQ damage)

The state of the surface of the HSQ film when HSQ (hydrogensilsesquioxane) was used as the low dielectric constant film was observed, and evaluated according to the following four grades.

A: No damage was observed.

〇: Damage was slightly observed.

MM ... no damage.

X: Damage was remarkable. (MSQ damage) W

28 When the MSQ (methyl silsesquioxane) was used as the low dielectric constant film, the state of the MSQ film surface was observed and evaluated according to the following four grades.

A: No damage was observed.

〇: Damage was slightly observed.

Δ: Damage was observed.

X: The damage was remarkable.

Table 5

* 1 “Remainder” in the amount of water is the remainder obtained by subtracting the amounts of the anticorrosive and the release agent from 100% by mass.

* 2 NMA E N—Methylaminoethanol

ME A Monoethanolamine

BTA benzotriazole

As described above, it can be seen that the release agent composition of the present invention has excellent release performance and anticorrosion performance. In this embodiment, the present invention is applied to a single damascene process. W

29, the present invention can be applied to a so-called dual damascene process.

A silicon wafer having a copper film formed on the entire surface of the substrate was immersed in a predetermined stripper at 80 for 10 minutes. The copper etching rate was measured from the thickness of the copper film before and after immersion. _(The stripping solution used was of the following composition. In order to eliminate the effect of pH fluctuation due to the difference in the amount of uric acid added, 2N — Aqueous ammonia was added to control the pH to 11.

80% by mass

Uric acid 0, 0.0001, 0.001, 0.01, 0.1, 1% by mass Water balance

NMAE (N-methylaminoethanol) was used as the amine. The results are shown in FIG. When the etching rate indicated by the vertical axis in the figure exceeds 4 nmZmin, the corrosion of the copper film becomes remarkable. From the results shown in the figure, it can be seen that excellent anticorrosion properties are exhibited by adding uric acid.

Example 7

The present embodiment is an example in which the release agent composition according to the present invention is applied to a process of forming a through hole on a copper wiring. As a peeling component, ammonium fluoride having a strong peeling action was used. The process was almost the same as that in Example 5, but the thickness of the nitride film and the type of etching gas were slightly different, and the _c evaluation results in which the deposit to be stripped was different from Example 5 are shown in the following table. The evaluation criteria for peelability and anticorrosion were the same as in Example 5. It was confirmed that those using uric acid exhibited the same peeling properties and anticorrosion properties as BTA derivatives. Table 6

NMP: N-methyl-2-pyrrolidone

D M S 0: Dimethyl sulfoxide Industrial applicability

As described above, the anticorrosive agent of the present invention contains specific components, so that corrosion of easily corrosive metals such as copper can be effectively prevented, and since it is highly safe, it is easy to handle. Since biological treatment is possible, wastewater treatment is also easy. Therefore, it can be suitably used for a manufacturing process of a semiconductor device provided with copper wiring.

Claims

The scope of the claims

1. An anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor wafer, comprising a heterocyclic compound having a six-membered ring containing a nitrogen atom as an anticorrosion component. Anticorrosive.

2. An anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor wafer.

-C (O H) = N—, or

One C O N H—

An anticorrosive comprising a heterocyclic compound having a 5- or 6-membered heterocyclic ring containing the following atomic group.

3. An anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor wafer, comprising purine or a derivative thereof as an anticorrosion component.

4. An anticorrosion agent for preventing corrosion of a metal film formed on a semiconductor substrate, which is characterized by containing a compound represented by the following general formula (1) as an anticorrosion component. .

! ,, A ₂ and A ₃ represent independently hydrogen atom, a hydroxyl group, a § alkyl group or an amino group having 1 to 5 carbon atoms. )

5. Anticorrosive agent, characterized in that the corrosion inhibitor of claim 4, at least one of A ₂ and A ₃ is a hydroxyl group.

6. The anticorrosive according to claim 4, wherein the compound represented by the general formula (1) is uric acid.

7. The anticorrosion agent according to claim 1, wherein the metal film is made of copper or a copper alloy containing copper as a main component.

8. An anticorrosion solution obtained by dissolving the anticorrosion agent according to any one of claims 1 to 7 in water or a water-soluble organic solvent.

9. An anticorrosion treatment solution used for anticorrosion treatment of a metal film formed on a semiconductor wafer, comprising the anticorrosion agent according to any one of claims 1 to 7.

10. The anticorrosion treatment liquid according to claim 9, wherein the metal film is made of copper or a copper alloy containing copper as a main component.

11. A storage solution for storing a semiconductor wafer having a metal film formed on a surface thereof, wherein the storage solution contains the anticorrosive according to any one of claims 1 to 7.

12. The storage solution according to claim 11, wherein the metal film is made of copper or a copper alloy containing copper as a main component.

13. A slurry for chemically and mechanically polishing a semiconductor wafer having a metal film formed on a surface thereof, wherein the slurry contains the anticorrosive according to any one of claims 1 to 7. Slurry for mechanical and mechanical polishing.

14. The slurry for chemical mechanical polishing according to claim 13, wherein the metal film is made of copper or a copper alloy containing copper as a main component.

15 5. A metal film is formed on the semiconductor wafer, a part of the metal film is chemically and mechanically polished, and the surface of the semiconductor wafer is cleaned using a cleaning solution. Item 10. An anticorrosion treatment method comprising performing an anticorrosion treatment on the metal film using the anticorrosion treatment solution according to Item 9.

16. The anticorrosion treatment method according to claim 15, wherein the metal film is made of copper or a copper alloy containing copper as a main component.