Cleaning solution composition used after metal film polishing

Abstract

To provide a cleaning solution composition used after metal film polishing that efficiently removes metal contaminants and organic contaminants generated after chemical mechanical polishing of a metal film and suppresses corrosion of metal wiring formed on a wafer.SOLUTION: A cleaning solution composition according to the present invention includes: a chelating agent containing amino acid; a pH adjuster comprising a quaternary ammonium compound; an etchant comprising an amine compound; and an inhibitor comprising pyridinecarboxylic acid; wherein the cleaning solution composition does not comprise an azole compound.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cleaning liquid composition for use after polishing a metal film. [Background technology]

[0002] Wafers are used to form microelectronic integrated circuits. Wafers contain materials such as silicon and are patterned with areas for the deposition of different materials with insulating, conductive, or anticonductive properties. To obtain accurate patterning, excess material used to form layers on the wafer must be removed. Also, to produce functional and reliable circuits, it is important to produce a flat or planar microelectronic wafer surface prior to subsequent processing. Therefore, it is necessary to remove and / or polish certain surfaces of microelectronic wafers.

[0003] Chemical mechanical polishing (CMP) is a process by which materials are removed from the surface of a microelectronic wafer by a combination of physical processes, such as abrasion, and chemical processes, such as oxidation or chelation. In its most basic form, CMP involves applying a slurry, e.g., a solution of an abrasive and an active compound, to a polishing pad, which then buffs, removes, planarizes, and polishes the surface of the microelectronic wafer. In integrated circuit manufacturing, CMP slurries are required to preferentially remove films, including composite layers of metals and other materials, to produce highly planar surfaces on the wafer for subsequent lithography or patterning, etching, and thin-film processing.

[0004] After the CMP process, contaminants such as residues generated during various processing operations, including multilayer film formation, etching, and the CMP process, and particles from removed layers are generated. These residues or contaminants can cause wiring damage during subsequent processes for forming metal wiring or various structures, and can increase surface damage to structures, resulting in poor electrical performance of semiconductor devices. Therefore, a cleaning process is performed as a necessary subsequent process after the CMP process to remove these residues or contaminants.

[0005] However, the cleaning solution composition generally used for cleaning after polishing is an alkaline aqueous solution containing OH. - Because azole compounds are abundant in azole compounds, they charge the abrasive particles and the wafer surface, facilitating the removal of the abrasive particles through electrical repulsion. However, they are unable to efficiently remove impurities such as metal contaminants and organic contaminants from the wafer surface after cleaning. In particular, cleaning liquid compositions containing azole compounds that have already been used have the problem that they remain on the wafer surface after cleaning and act as organic defects.

[0006] Furthermore, the cleaning solution may unintentionally corrode the metal wiring material formed on the wafer, which may result in a problem of reduced reliability and quality of the manufactured semiconductor. Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide a cleaning liquid composition for use after polishing a metal film, which can efficiently remove metallic contaminants and organic contaminants generated after chemical-mechanical polishing of a metal film.

[0008] However, the problems that the present invention aims to solve are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0009] One aspect of the present invention provides a cleaning liquid composition comprising: a chelating agent containing an amino acid; a pH adjuster containing a quaternary ammonium compound; an etchant containing an amine compound; and an inhibitor containing pyridinecarboxylic acid; and the cleaning liquid composition is free of an azole compound.

[0010] According to one embodiment, the amino acid may be any one or more selected from the group consisting of cysteine, histidine, proline, arginine, glycine, lysine, and leucine.

[0011] According to one embodiment, the quaternary ammonium compound may include at least one selected from the group consisting of tris(hydroxyethyl)methylammonium hydroxide (THEMAH), tetramethylammonium hydroxide (TMAH), choline hydroxide, tetraethylammonium hydroxide (TEAH), tetrabutylammonium hydroxide (TBAH), and ethyltrimethylammonium hydroxide (ETMAH).

[0012] According to one embodiment, the amine compound may include one or more selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, diethylamine, triethylamine, diethylhydroxylamine, and triethylenetetramine.

[0013] According to one embodiment, the pyridinecarboxylic acids may include any one or more selected from the group consisting of nicotinic acid, quinolinic acid, and isonicotinic acid.

[0014] According to one embodiment, the content of the amino acid may be 0.1% to 5% by weight relative to the total cleaning liquid composition.

[0015] According to one embodiment, the content of the quaternary ammonium compound may be 0.1% by weight to 10% by weight relative to the total weight of the cleaning liquid composition.

[0016] According to one embodiment, the content of the amine compound may be 0.1% by weight to 10% by weight relative to the total weight of the cleaning liquid composition.

[0017] According to one embodiment, the content of the pyridine carboxylic acid may be 0.01% by weight to 5% by weight relative to the total cleaning liquid composition.

[0018] According to one embodiment, the cleaning liquid composition may have a pH of 8 to 13.

[0019] According to one embodiment, the cleaning solution composition may be used in a brush cleaning step of a substrate after polishing a metal film.

[0020] According to one embodiment, the cleaning liquid composition may have a polishing rate for a copper (Cu) film of 1.0 Å / min or less.

[0021] According to one embodiment, the cleaning composition is characterized in that no inhibitor remains on the surface of the metal polishing film after cleaning.

[0022] One aspect of the present invention provides a method for cleaning a semiconductor device wafer, comprising the steps of polishing a metal-containing polishing film formed on the semiconductor device wafer, and then cleaning the semiconductor device wafer with a cleaning liquid composition according to any one of claims 1 to 14.

[0023] According to one embodiment, the metal may include one or more selected from the group consisting of copper (Cu), cobalt (Co), ruthenium (Ru), tungsten (W), tantalum nitride (TaN), molybdenum (Mo), and titanium (Ti). [Effects of the Invention]

[0024] The cleaning liquid composition for use after polishing a metal film according to the present invention is capable of removing metal contaminants and organic impurities generated after chemical and mechanical polishing of a metal film formed on a wafer, and also has the effect of suppressing corrosion of metal wiring formed on the wafer.

[0025] The effects of the present invention are not limited to the effects described above, but should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the present invention or the claims. [Brief explanation of the drawings]

[0026] [Figure 1] 1 shows the results of defect evaluation of wafers after cleaning using a composition according to an embodiment of the present invention.

[0027] [Figure 2] 1 shows the results of evaluating residual organic matter on a wafer after cleaning using a composition according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, various modifications may be made to the embodiments, and the scope of the patent application is not limited or restricted by such embodiments. It should be understood that all modifications, equivalents, and alternatives to the embodiments are included in the scope of the patent.

[0029] The terms used in the embodiments are merely used for the purpose of explanation and are not to be construed as limiting. A singular expression includes a plural expression unless the context clearly indicates otherwise. In this specification, the terms "comprise" or "have" indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, and should be understood as not precluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0030] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the art to which the present invention pertains. Commonly used predefined terms should be interpreted as having a meaning consistent with the meaning they have in the context of the relevant art, and should not be interpreted as having an ideal or overly formal meaning unless expressly defined herein.

[0031] In addition, in the description with reference to the accompanying drawings, the same components are denoted by the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted. In the description of the embodiments, if a detailed description of related known technology is determined to unnecessarily obscure the gist of the embodiments, the detailed description thereof will be omitted.

[0032] Furthermore, in describing components of the embodiments, terms such as first, second, A, B, (a), (b), etc. are used to distinguish the component from other components, and do not limit the essence, order, or sequence of the component.

[0033] Components having functions common to those included in any of the embodiments will be described using the same names in other embodiments. Unless otherwise specified, the description of one embodiment will be applied to the other embodiments, and detailed description will be omitted to the extent that they overlap.

[0034] Throughout the specification, when any part "comprises" any component, this does not mean that it excludes other components, but that it may further include other components.

[0035] The present invention relates to a cleaning liquid composition comprising: a chelating agent containing an amino acid; a pH adjuster containing a quaternary ammonium compound; an etchant containing an amine compound; and an inhibitor containing pyridinecarboxylic acid; and is free of an azole compound.

[0036] The cleaning solution composition according to the present invention may contain a chelating agent. The chelating agent prevents redeposition of removed metals on the semiconductor surface and improves the effectiveness of removing polishing particles, metal impurities, and the like remaining on semiconductor device wafers. In addition, the chelating agent functions as a pH buffer in the cleaning solution composition and also provides a cleaning effect for polishing particles, organic matter, impurities, and the like remaining after the polishing process.

[0037] According to one embodiment, the chelating agent may include an amino acid, and the amino acid may be any one or more selected from the group consisting of cysteine, histidine, proline, arginine, glycine, lysine, and leucine.

[0038] According to one embodiment, the content of the amino acid may be 0.1 wt % to 5 wt %, preferably 0.5 wt % to 3 wt %, of the total cleaning solution composition. If the content of the amino acid is less than the lower limit, the effect of removing contaminants such as polishing particles and metal impurities decreases, and if the content of the amino acid is more than the upper limit, the amino acid may not be sufficiently dissolved and may be adsorbed onto the wafer surface.

[0039] The cleaning liquid composition according to the present invention may contain a pH adjuster. The pH adjuster may include a quaternary ammonium compound, and the quaternary ammonium compound may include at least one selected from the group consisting of tris(hydroxyethyl)methylammonium hydroxide (THEMAH), tetramethylammonium hydroxide (TMAH), choline hydroxide, tetraethylammonium hydroxide (TEAH), tetrabutylammonium hydroxide (TBAH), and ethyltrimethylammonium hydroxide (ETMAH). According to one embodiment, the content of the quaternary ammonium compound may be 0.1 wt % to 10 wt % of the total cleaning liquid composition.

[0040] The pH of the cleaning liquid composition can be appropriately adjusted using a pH adjuster, and the pH of the pH-adjusted cleaning composition may be 8 to 13, preferably 10 to 12. If the pH does not reach the above range, corrosion of metals such as copper may occur.

[0041] The cleaning liquid composition according to the present invention may include an etchant, and the etchant may include an amine compound. x The etchant in the composition combines with organic materials such as azole to induce organic defects, but CuO xThe amine compound reduces Cu to a Cu hydroxide complex, dissolving and removing it. According to one embodiment, the amine compound may include at least one selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, diethylamine, triethylamine, diethylhydroxylamine, and triethylenetetramine. According to one embodiment, the content of the amine compound may be 0.1 wt % to 20 wt %, preferably 1 wt % to 15 wt %, of the total cleaning solution composition. If the content of the amine compound exceeds the upper limit, the Cu filling the pattern may be corroded, and if the content is below the lower limit, the cleaning power may be reduced.

[0042] The cleaning solution composition according to the present invention may contain an inhibitor. The inhibitor forms a coordination bond with Cu on the wafer surface to protect the Cu surface and inhibit metal corrosion. In the present invention, the inhibitor may be a pyridine compound free of NH and amine groups, preferably pyridinecarboxylic acids. According to one embodiment, the pyridinecarboxylic acids may include at least one selected from the group consisting of nicotinic acid, quinolinic acid, and isonicotinic acid. According to one embodiment, the content of the pyridinecarboxylic acids may be 0.01 wt % to 5 wt % of the total cleaning solution composition. If the content of the pyridinecarboxylic acids is less than the lower limit, Cu corrosion may occur, and if it exceeds the upper limit, the pyridinecarboxylic acids may be adsorbed onto the wafer surface, causing defects.

[0043] According to one embodiment, the cleaning solution composition of the present invention is characterized by being free of azole compounds. Azole compounds primarily function as inhibitors in cleaning solution compositions to prevent corrosion, but can cause organic defects by remaining on the wafer surface after cleaning. Therefore, the present invention replaces azole compounds as inhibitors with pyridinecarboxylic acids, thereby enhancing metal corrosion inhibition while preventing organic contamination.

[0044] The cleaning composition according to the present invention can be used in the brush cleaning step of a substrate after polishing a metal film. After the chemical mechanical polishing process of a semiconductor device wafer, buffing / brush cleaning and deionized water (DI water) cleaning steps are performed. The cleaning composition according to the present invention can be used in the buffing and brush cleaning steps.

[0045] According to one embodiment, the cleaning solution composition may have a polishing rate of 1.0 Å / min or less for a copper (Cu) film and is characterized in that no inhibitor remains on the surface of the metal polishing film after cleaning. The cleaning solution composition according to the present invention contains an inhibitor, which has the effect of inhibiting corrosion of the metal film, and because the inhibitor does not contain an azole compound, it has the effect of minimizing the amount of inhibitor remaining on the surface of the metal film.

[0046] One aspect of the present invention provides a method for cleaning a semiconductor device wafer, comprising polishing a metal-containing polishing film formed on the semiconductor device wafer and then cleaning the semiconductor device wafer with the cleaning solution composition described in claims 1 to 14. After chemical mechanical polishing of a semiconductor device wafer, contaminants such as residues generated during polishing or particles from the polished layer are generated. These residues or contaminants can cause wiring damage and increase damage to the structure surface during subsequent processes for forming metal wiring or various structures, thereby causing poor electrical performance of semiconductor devices, making a cleaning process essential. The cleaning solution composition of the present invention is used in the cleaning process, and when used in the cleaning process, it can minimize corrosion of previously formed metal wiring and efficiently remove residues and contaminants.

[0047] According to one embodiment, the metal formed on the semiconductor device wafer may include any one or more selected from the group consisting of copper (Cu), cobalt (Co), ruthenium (Ru), tungsten (W), tantalum nitride (TaN), molybdenum (Mo), and titanium (Ti).

[0048] The present invention will be described in more detail with reference to the following embodiments. The following embodiments are provided for the purpose of illustrating the present invention, and the scope of the present invention is not limited thereto. [Embodiment] 1. Manufacturing example

[0049] The cleaning liquid compositions of Examples 1 to 6 and Comparative Examples 1 to 6, each having a pH of 12 to 13, were prepared by adding 7 wt% monoethanolamine as an etchant, 7 wt% THEMAH as a pH adjuster, and chelating agents and inhibitors according to Table 1 below.

[0050] [Table 1]

[0051] 2. Test Example 1: Measurement of the degree of metal corrosion

[0052] The corrosion rates of copper (Cu), cobalt (Co), and tungsten (W) were measured in terms of etch rate (Å / min) for the compositions of the above-mentioned Examples 1 to 6 and Comparative Examples 1 to 6. (Measurement conditions and methods added)

[0053] The results are shown in Table 2 below.

[0054] [Table 2]

[0055] 3. Test Example 2: Measurement of the number of defects

[0056] After the CMP process, wafers were cleaned using ultrapure distilled water (DIW), a composition containing an azole compound, and the composition of embodiment 1 not containing an azole compound, and then the occurrence of defects was measured, and the results are shown in Figure 1. "w / o azole" indicates a wafer cleaned using the composition of embodiment 1, and "w / azole" indicates a wafer cleaned using a composition containing an azole compound.

[0057] Referring to FIG. 1, it can be seen that although the comparative composition containing an azole compound also reduced the number of defects compared to cleaning using DIW alone, the composition according to one embodiment of the present invention, which does not contain an azole compound, was far superior in reducing defects. 4. Test Example 3: Organic Matter Evaluation

[0058] To evaluate the amount of organic matter remaining after wafer cleaning using the cleaning solution, the corrosion voltage (Ecorr) was measured using Tafel analysis. As shown in Table 3 below, "Initial" refers to the corrosion voltage measured without contaminating the Cu surface, and "Contaminated" refers to a wafer contaminated by deep-dipping the Cu wafer in azole-1 or azole-2. "W / o azole" refers to a wafer that was contaminated by cleaning the contaminated wafer using the composition of Example 1, and "w / azole" refers to a wafer that was contaminated by cleaning the contaminated wafer using a composition containing an azole compound.

[0059] [Table 3]

[0060] Table 4 below and Figure 2 show the results of Tafel analysis performed on each wafer.

[0061] [Table 4]

[0062] Referring to Table 4 and FIG. 2, it can be seen that the initial corrosion voltage value is calculated to be low because there is no inhibitor on the surface, and that if an inhibitor such as azole is treated, the corrosion voltage value is measured to be high. Therefore, when cleaning is performed using the composition of embodiment 1 which does not contain an azole compound, the corrosion voltage value is reduced to be closer to the initial corrosion voltage value than when cleaning is performed using a cleaning liquid composition which contains an azole compound, and it can be seen that organic contaminants are removed efficiently.

[0063] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention is not limited to the above-described embodiments, and a person skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques may be performed in an order different from that described, and / or the described components may be combined or combined in a form different from that described, or may be substituted or replaced by other components or equivalents, and still achieve appropriate results.

[0064] Accordingly, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

Claims

1. a chelating agent comprising an amino acid; a pH adjuster containing a quaternary ammonium compound; an etchant containing an amine compound; an inhibitor comprising a pyridinecarboxylic acid; A cleaning liquid composition characterized by not containing an azole compound.

2. 2. The cleaning liquid composition according to claim 1, wherein the amino acid is at least one selected from the group consisting of cysteine, histidine, proline, arginine, glycine, lysine, and leucine.

3. 2. The cleaning liquid composition according to claim 1, wherein the quaternary ammonium compound comprises at least one selected from the group consisting of tris(hydroxyethyl)methylammonium hydroxide (THEMAH; Tris(hydroxyethyl)methylammonium hydroxide), tetramethylammonium hydroxide (TMAH; Tetramethylammonium hydroxide), choline hydroxide, tetraethylammonium hydroxide (TEAH; Tetraethylammonium hydroxide), tetrabutylammonium hydroxide (TBAH; Tetrabutylammonium hydroxide), and ethyltrimethylammonium hydroxide (ETMAH; Ethyltrimethylammonium hydroxide).

4. 2. The cleaning liquid composition according to claim 1, wherein the amine compound comprises at least one selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, ethylenediamine, diethylenetriamine, diethylamine, triethylamine, diethylhydroxylamine, and triethylenetetramine.

5. 2. The cleaning solution composition according to claim 1, wherein the pyridinecarboxylic acids include at least one selected from the group consisting of nicotinic acid, quinolinic acid, and isonicotinic acid.

6. The cleaning composition according to claim 1, wherein the content of the amino acid is 0.1% to 5% by weight based on the total weight of the cleaning composition.

7. The cleaning composition of claim 1, wherein the content of the quaternary ammonium compound is 0.1 to 10% by weight based on the total weight of the cleaning composition.

8. The cleaning composition according to claim 1, wherein the content of the amine compound is 0.1% by weight to 10% by weight based on the total weight of the cleaning composition.

9. The cleaning composition according to claim 1, wherein the content of the pyridine carboxylic acid is 0.01 to 5% by weight based on the total weight of the cleaning composition.

10. The cleaning liquid composition according to claim 1, which has a pH of 8 to 13.

11. The cleaning composition according to claim 1 , wherein the cleaning composition is used in a brush cleaning step of a substrate after polishing a metal film.

12. 2. The cleaning liquid composition according to claim 1, wherein the polishing rate for a copper (Cu) film is 1.0 Å / min or less.

13. 2. The cleaning composition according to claim 1, wherein no inhibitor remains on the surface of the metal polished film after cleaning.

14. After polishing a metal-containing polishing film formed on a semiconductor device wafer, A method for cleaning a semiconductor device wafer, comprising the step of cleaning the semiconductor device wafer with the cleaning liquid composition according to any one of claims 1 to 13.

15. 15. The method for cleaning a semiconductor device wafer according to claim 14, wherein the metal includes at least one selected from the group consisting of copper (Cu), cobalt (Co), ruthenium (Ru), tungsten (W), tantalum nitride (TaN), molybdenum (Mo), and titanium (Ti).

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