TWI886773B - Cmp slurry composition for polishing copper and method of polishing copper using the same - Google Patents

Abstract

A CMP slurry composition for polishing copper and a polishing method using the same. The CMP slurry composition includes: at least one solvent selected from among a polar solvent and a non-polar solvent; an abrasive agent; and a corrosion inhibitor, wherein the corrosion inhibitor includes a compound represented by Formula 1 or a salt thereof.

Description

CMP slurry composition for grinding copper and method for grinding copper using the same

The present invention relates to a CMP slurry composition for grinding copper and a method for grinding copper using the same. CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefits of Korean Patent Application No. 10-2023-0084854 filed on June 30, 2023 in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference.

A process for polishing a copper film as a metal interconnect of a semiconductor device is required to ensure a sufficiently high polishing rate, good polishing selectivity of the copper film relative to a barrier metal or dielectric, a suitable flatness level of the polished surface, and a low defect level. In particular, as the thickness of interconnects and semiconductor layers decreases due to pattern miniaturization, a CMP slurry capable of ensuring high flatness of the polished surface is required.

Methods for improving planarity generally include increasing the amount of corrosion inhibitor used, adopting a polymeric film forming agent, and reducing the size and/or content of the abrasive used. However, these methods reduce the polishing rate with respect to copper, thereby creating a balance between the polishing rate and planarity. Conventionally, triazole or tetrazole compounds have been used as corrosion inhibitors. However, although they can provide a certain degree of corrosion protection when used in large amounts, such triazole or tetrazole compounds have the problem of reducing the polishing rate with respect to copper.

An object of the present invention is to provide a CMP slurry composition for polishing copper, which can prevent corrosion of the copper film.

Another object of the present invention is to provide a CMP slurry composition for polishing copper, which can improve the flatness of the polished surface by reducing dishing or erosion while ensuring a high polishing rate with respect to the copper film.

Another object of the present invention is to provide a method for polishing copper, which comprises polishing a copper film using the CMP slurry composition for polishing copper according to the present invention.

One aspect of the present invention relates to a CMP slurry composition for polishing copper.

A CMP slurry composition for polishing copper comprises: at least one solvent selected from polar solvents and non-polar solvents; a polishing agent; and a corrosion inhibitor, wherein the corrosion inhibitor comprises a compound represented by Formula 1 or a salt thereof.

[Formula 1]

(wherein _R1 and _R2 are each independently hydrogen, substituted or unsubstituted straight or branched _C1 to _C5 alkyl, or substituted or unsubstituted _C6 to _C10 aryl; _R3 is hydrogen or substituted or unsubstituted straight or branched _C1 to _C3 alkyl; and _R4 is substituted or unsubstituted straight or branched _C1 to _C5 alkyl, substituted or unsubstituted straight or branched _C2 to _C5 alkenyl, or substituted or unsubstituted straight or branched _C2 to _C5 alkynyl).

The polishing method according to the present invention comprises polishing a copper film using the CMP slurry composition for polishing copper according to the present invention.

The present invention provides a CMP slurry composition for polishing copper, which can prevent corrosion of the copper film.

The present invention provides a CMP slurry composition for polishing copper, which can improve the flatness of the polished surface by reducing dishing or erosion while ensuring a high polishing rate with respect to the copper film.

The present invention provides a method for polishing copper, which comprises polishing a copper film using the CMP slurry composition for polishing copper according to the present invention.

The terms used herein are for the purpose of describing exemplary embodiments and are not intended to limit the present invention.As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

The CMP slurry composition for grinding copper according to the present invention comprises: at least one solvent selected from polar solvents and non-polar solvents; abrasive; and corrosion inhibitor, wherein the corrosion inhibitor comprises a compound represented by Formula 1 or a salt thereof:

[Formula 1]

(wherein _R1 and _R2 are each independently hydrogen, substituted or unsubstituted _C1 to _C5 alkyl, or substituted or unsubstituted _C6 to _C10 aryl; _R3 is hydrogen or substituted or unsubstituted _C1 to _C3 alkyl; and _R4 is substituted or unsubstituted _C1 to _C5 alkyl, substituted or unsubstituted _C2 to _C5 alkenyl, or substituted or unsubstituted _C2 to _C5 alkynyl).

As used herein, the "substituted" in the expression "substituted or unsubstituted" means that at least one hydrogen atom in the corresponding functional group is substituted with a _C1 to _C10 alkyl group, a _C2 to _C10 alkenyl group, a _C2 to _C10 alkynyl group, a _C6 to _C20 aryl group, a _C7 to _C20 aralkyl group, a _C3 to _C20 heteroaryl group, a _C3 to _C10 alicyclic group, a hydroxyl group, an amino group, or the like.

The CMP slurry composition according to the present invention can prevent corrosion of the copper film. In addition, the CMP slurry composition according to the present invention can improve the flatness of the polished surface by reducing dishing or corrosion while minimizing the reduction in the polishing rate with respect to the copper film. In addition, compared with a conventional composition containing a compound represented by Formula 1 or a salt thereof as a corrosion inhibitor, the CMP slurry composition according to the present invention can provide improved flatness of the polished surface without sacrificing a high polishing rate with respect to the copper film.

Hereinafter, each component of the CMP slurry composition for polishing copper (hereinafter referred to as "CMP slurry composition") according to the present invention will be described in detail.

At least one solvent selected from polar solvents and non-polar solvents can reduce the friction of the abrasive on the copper film when the abrasive is used to grind the copper film. At least one selected from polar solvents and non-polar solvents can include water (e.g., ultrapure water), organic amines, organic alcohols, organic alcohol amines, organic ethers, organic ketones, etc. Preferably, at least one selected from polar solvents and non-polar solvents can include ultrapure water, i.e., deionized water. At least one selected from polar solvents and non-polar solvents can be present in the CMP slurry composition in the remaining amount, for example, 30 wt % to 99 wt %.

The abrasive may include a typical abrasive for copper grinding. For example, the abrasive may be abrasive particles of a metal oxide or a non-metal oxide. The abrasive may include, for example, at least one selected from silica (e.g., colloidal silica and fumed silica), alumina, daltonia, titanium dioxide, and zirconia. In one embodiment, the abrasive may be silica (e.g., colloidal silica), but is not limited thereto.

The abrasive is composed of spherical or non-spherical particles and may have an average initial particle size ( _D50 ) of 10 nm to 150 nm, for example, 20 nm to 70 nm. Within this range, the abrasive can ensure a high polishing rate with respect to the copper film, prevention of scratches, and improved flatness of the polished surface. Herein, "average particle size ( _D50 )" is a typical particle size measurement known in the art and refers to a particle size corresponding to 50% by volume of the abrasive particles when the abrasive particles are distributed in order from smallest to largest by volume.

The abrasive may be a non-surface-modified abrasive or a surface-modified abrasive. Surface-modified abrasive particles may be more stably dispersed in the CMP composition and/or may grind the copper film at a higher grinding rate. The surface modification of the abrasive may be performed by treating the abrasive with a compound for surface modification. In one embodiment, the compound for surface modification may include a silane compound. When the abrasive is silicon dioxide, the abrasive may be easily surface-modified with a silane compound. The silane compound may include at least one selected from the following: alkoxysilane containing alkyl, alkoxysilane containing amine, tetraalkoxysilane and alkoxysilane containing _C1 to _C10 alkyl, but is not limited thereto. In another embodiment, silica can be initially surface-modified with a compound containing sulfonic acid or phosphoric acid groups, followed by a secondary surface-modification with an alkoxysilane (e.g., tetraethoxysilane).

The abrasive may be present in the CMP slurry composition in an amount of 0.001 wt % to 20 wt %, preferably 0.005 wt % to 10 wt %, more preferably 0.01 wt % to 5 wt %, and still more preferably 0.05 wt % to 3 wt %. Within this range, it is possible to ensure a sufficient polishing rate with respect to the copper film, prevention of scratching, and improved dispersion stability of the composition.

The corrosion inhibitor includes a compound represented by Formula 1 or a salt thereof.

[Formula 1]

(wherein _R1 and _R2 are each independently hydrogen, substituted or unsubstituted straight or branched _C1 to _C5 alkyl, or substituted or unsubstituted _C6 to _C10 aryl; _R3 is hydrogen or substituted or unsubstituted straight or branched _C1 to _C5 alkyl; and _R4 is substituted or unsubstituted straight or branched _C1 to _C5 alkyl, substituted or unsubstituted straight or branched _C2 to _C5 alkenyl, or substituted or unsubstituted straight or branched _C2 to _C5 alkynyl).

The compound represented by Formula 1 or a salt thereof can prevent corrosion of a copper film. The compound represented by Formula 1 or a salt thereof can improve the flatness of a polished surface by reducing surface defects (e.g., corrosion) while minimizing a decrease in the polishing rate with respect to the copper film. The compound represented by Formula 1 or a salt thereof can significantly improve the flatness of a polished surface even in a small amount compared to conventional triazole-based or tetrazole-based corrosion inhibitors.

Preferably, _R1 to _R3 are each independently hydrogen or methyl.

Preferably, _R4 is a substituted or unsubstituted linear or branched _C1 to _C5 alkyl group. The substituted or unsubstituted linear or branched _C1 to _C5 alkyl group can increase the solubility of the compound represented by Formula 1 or its salt in water, thereby facilitating the preparation of the CMP slurry composition and allowing the compound represented by Formula 1 or its salt to provide the desired effect even in a small amount. For example, _R4 can be allyl, n-propyl, n-butyl, isobutyl, pentyl (n-pentyl) or isopentyl.

The compound represented by Formula 1 may be a compound represented by one of Formula 1-1 to Formula 1-6: [Formula 1-1] [Formula 1-2] [Formula 1-3] [Formula 1-4] [Formula 1-5] [Formula 1-6]

The compound of Formula 1 can be prepared by a typical method known to those skilled in the art. For example, the compound represented by Formula 1 can be prepared by introducing an azo or azo group into an amino-containing azole compound through nitrogenation of the azole compound, followed by reaction with NHR ₃ R ₄ (wherein R ₃ and R ₄ are the same as defined in Formula 1).

The salt of the compound of Formula 1 may be prepared by reacting the compound represented by Formula 1 with an acid or a base, but is not limited thereto.

The compound represented by Formula 1 or a salt thereof may be present in the corrosion inhibitor in an amount of 1 wt % to 100 wt %, for example, 5 wt % to 100 wt % or 50 wt % to 100 wt %. Within this range, the compound represented by Formula 1 or a salt thereof may provide the desired effects described above.

The corrosion inhibitor may further include a corrosion inhibitor other than the compound represented by Formula 1. The corrosion inhibitor other than the compound represented by Formula 1 may include at least one selected from a triazole-based corrosion inhibitor and a tetrazole-based corrosion inhibitor.

The triazole corrosion inhibitor may include: triazole compounds, including 1,2,4-triazole, 1,2,3-triazole, etc.; diaminotriazole compounds, including 3,5-diamino-1,2,4-triazole, etc.; methylbenzotriazole compounds, including 5-methylbenzotriazole, 4-methylbenzotriazole, etc.; and benzotriazole compounds, including ethylbenzotriazole, propylbenzotriazole, butylbenzotriazole, pentylbenzotriazole, hexylbenzotriazole, etc. The triazole corrosion inhibitor may be present in the CMP slurry composition in the form of the triazole corrosion inhibitor itself or a salt thereof.

The tetrazole corrosion inhibitor may include at least one selected from tetrazole, 5-aminotetrazole, 5-methyltetrazole and 5-phenyltetrazole, but is not limited thereto. The tetrazole corrosion inhibitor may be present in the CMP slurry composition in the form of the tetrazole corrosion inhibitor itself or a salt thereof.

The corrosion inhibitor may be present in the CMP slurry composition in an amount of 0.001 wt % to 5 wt %, preferably 0.005 wt % to 0.5 wt %. Within this range, the CMP slurry composition can significantly improve the flatness of the polished surface by reducing surface defects (e.g., erosion) during polishing while providing an increased polishing rate for copper films.

The CMP slurry composition may further include at least one selected from a chelating agent and an oxidizing agent.

The chelating agent chelates metal cations and metal oxides generated when the copper film is polished. Therefore, the chelating agent ensures suppression of the re-adsorption of the metal oxides onto the copper film, an increase in the polishing rate of the copper film, and a reduction in surface defects.

The chelating agent may include at least one selected from the group consisting of an organic acid, a salt of an organic acid, an amino acid, a salt of an amino acid, an alcohol (e.g., a diol, a triol, and a polyol), an amine-containing compound, phosphoric acid, and a phosphate. Preferably, the chelating agent is an amino acid. In this document, unlike an amino acid, "organic acid" may refer to an acid that does not contain an amine group ( _-NH2 ). Using an amino acid as a chelating agent may provide an increased polishing rate with respect to a copper film compared to using an organic acid or a salt thereof or a phosphate as a chelating agent.

The organic acid may include an organic carboxylic acid having one or more carboxyl groups. For example, the organic acid may include a saturated acid such as glycolic acid, lactic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, formic acid, salicylic acid, dimethylbutyric acid, octanoic acid, benzoic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid and pimelic acid, maleic acid, fumaric acid, itaconic acid, phthalic acid and citric acid. For example, the salt of the organic acid may include ammonium citrate, ammonium acetate, etc.

The amino acid may include at least one selected from the group consisting of glycine, alanine, serine, asparagine, glutamic acid, proline, hydroxyproline, arginine, cystine, histidine, tyrosine, leucine, lysine, methionine, valine, isoleucine, threonine, tryptophan, and phenylalanine. Preferably, the amino acid is glycine, which can provide a further increased polishing rate with respect to the copper film.

The phosphate may include triammonium phosphate, hydrated triammonium phosphate, and the like.

The chelating agent may be present in the CMP slurry composition in an amount of 0.01 wt % to 10 wt %, preferably 0.1 wt % to 5 wt %. Within this range, the chelating agent can improve the polishing rate of the copper film, the dispersion stability of the composition, and the surface properties of the copper film after polishing.

The oxidizing agent can promote the polishing of the copper film by oxidizing the copper film, and can improve the surface roughness of the copper film after polishing by smoothing the surface of the copper film.

The oxidizing agent may include at least one selected from the following: an inorganic per-compound, an organic per-compound, bromic acid or its salt, nitric acid or its salt, chloric acid or its salt, chromic acid or its salt, iodic acid or its salt, iron or its salt, copper or its salt, rare earth metal oxide, transition metal oxide and potassium dichromate. Herein, "per-compound" refers to a compound containing at least one peroxide group (-O-O-) or containing an element in the highest oxidation state. Preferably, the oxidizing agent is a per-compound. For example, the per-compound may include at least one selected from hydrogen peroxide, potassium periodate, calcium persulfate and potassium ferrocyanide. Preferably, the per-compound is hydrogen peroxide.

The oxidizing agent may be present in the CMP slurry composition in an amount of 0.1 wt % to 5 wt %, preferably 0.5 wt % to 3 wt %. Within this range, the CMP slurry composition may exhibit good polishing performance.

The CMP slurry composition may further include a pH adjuster. The pH adjuster may include an organic base, such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, sodium carbonate, and potassium carbonate. Alternatively, the pH adjuster may include an inorganic acid, such as at least one selected from nitric acid, phosphoric acid, hydrochloric acid, and sulfuric acid. The pH adjuster may be present in the CMP slurry composition in an amount of 1 wt % or less.

The CMP slurry composition may further include typical additives such as surfactants, dispersants, modifiers and biocides.

The CMP slurry composition may have a pH of 5 to 9 (preferably, 6 to 8).

The polishing method according to the present invention comprises polishing a copper film using the CMP slurry composition according to the present invention.

Then, the present invention will be described in more detail with reference to some examples. It should be understood that these examples are provided for illustration only and should not be interpreted as limiting the present invention in any way.

Examples 1

After dissolving 0.084 g (0.001 mol) of 3-amino-1,2,4-triazole in 100 g of distilled water, 0.101 g (36 wt%, 0.001 mol) of HCl was added to the solution, which was then vigorously stirred in an ice water bath at 0°C to 5°C. Thereafter, 1.3 g (5 wt%, 0.001 mol) of NaNO ₂ was slowly added dropwise thereto, and the resulting product was stirred and allowed to stand for 1 hour to prepare an azo salt. After dissolving 0.057 g (0.001 mmol) of allylamine in a mixture of 50 g of ethanol and 50 g of ultrapure water, 4 g of a 2.5 M NaOH aqueous solution was added to the solution, which was then added dropwise to the reactor containing the azo salt for 30 minutes. Thereafter, the obtained product was stirred and allowed to stand for 1 hour, and then dried under reduced pressure, thereby obtaining 0.145 g of the compound represented by Formula 1-1. The NMR result obtained for the prepared compound is as follows, which shows that the compound represented by Formula 1-1 was prepared. NMR result: 1H NMR, 4.01 (2H), 4.91-5.07 (2H), 5.93 (1H), 8.01 (1H).

The CMP slurry composition was prepared by stirring 0.33 wt % of an abrasive (colloidal silica, NP60, average particle size: 50 nm), 1.3 wt % of glycine (solid, J L CHEM Co., Ltd.) as a chelating agent, 0.02 wt % of the prepared compound (compound represented by Formula 1-1) as a corrosion inhibitor, and the remainder of ultrapure water, based on the total weight of the CMP slurry composition. A pH adjuster (nitric acid or potassium hydroxide) was used to adjust the pH of the CMP slurry composition to 7.3. Thereafter, 1.00 wt % of hydrogen peroxide (liquid, DONGWOO Fine-Chem Co., Ltd.) was added as an oxidizing agent, thereby obtaining a CMP slurry composition for evaluation of the properties shown in Table 1. In Table 1, "-" means that the corresponding component was not used.

Examples 2

After dissolving 0.084 g (0.001 mol) of 3-amino-1,2,4-triazole in 100 g of distilled water, 0.101 g (36 wt%, 0.001 mol) of HCl was added to the solution, which was then vigorously stirred in an ice water bath at 0°C to 5°C. Thereafter, 1.3 g (5 wt%, 0.001 mol) of NaNO ₂ was slowly added dropwise thereto, and the resulting product was stirred and allowed to stand for 1 hour to prepare the azo salt. After dissolving 0.059 g (0.001 mmol) of n-propylamine in a mixture of 50 g of ethanol and 50 g of ultrapure water, 4 g of a 2.5 M NaOH aqueous solution was added to the solution, which was then added dropwise to the reactor containing the azo salt for 30 minutes. Thereafter, the obtained product was stirred and allowed to stand for 1 hour, and then dried under reduced pressure, thereby obtaining 0.146 g of the compound represented by Formula 1-2. The NMR result obtained for the prepared compound is as follows, which shows that the compound represented by Formula 1-2 was prepared. NMR result: 1H NMR, 3.43 (2H), 6.53-6.81 (2H), 8.18 (1H).

A CMP slurry composition was prepared in the same manner as in Example 1, except that the type and content (unit: wt %) of each component of the composition were changed as listed in Table 1.

Examples 3

After dissolving 0.084 g (0.001 mol) of 3-amino-1,2,4-triazole in 100 g of distilled water, 0.101 g (36 wt%, 0.001 mol) of HCl was added to the solution, which was then vigorously stirred in an ice water bath at 0°C to 5°C. Thereafter, 1.3 g (5 wt%, 0.001 mol) of NaNO ₂ was slowly added dropwise thereto, and the resulting product was stirred and allowed to stand for 1 hour to prepare an azo salt. After dissolving 0.073 g (0.001 mmol) of n-butylamine in 100 g of ultrapure water, 4 g of a 2.5 M NaOH aqueous solution was added to the solution, which was then added dropwise to the reactor containing the azo salt for 30 minutes. Thereafter, the obtained product was stirred and allowed to stand for 1 hour, and then dried under reduced pressure, thereby obtaining 0.15 g of the compound represented by Formula 1-3. The NMR result obtained for the prepared compound is as follows, which shows that the compound represented by Formula 1-3 was prepared. NMR result: 1H NMR, 0.88 (3H), 1.31 (2H), 1.67 (2H), 3.61 (2H), 8.01 (1H).

A CMP slurry composition was prepared in the same manner as in Example 1, except that the type and content of each component of the composition were changed as listed in Table 1.

Examples 4

After dissolving 0.084 g (0.001 mol) of 3-amino-1,2,4-triazole in 100 g of distilled water, 0.101 g (36 wt%, 0.001 mol) of HCl was added to the solution, which was then vigorously stirred in an ice water bath at 0°C to 5°C. Thereafter, 1.3 g (5 wt%, 0.001 mol) of NaNO ₂ was slowly added dropwise thereto, and the resulting product was stirred and allowed to stand for 1 hour to prepare an azo salt. After dissolving 0.071 g (0.001 mmol) of isobutylamine in 100 g of ultrapure water, 4 g of a 2.5 M NaOH aqueous solution was added to the solution, which was then added dropwise to the reactor containing the azo salt for 30 minutes. Thereafter, the resulting product was stirred and allowed to stand for 1 hour, followed by drying under reduced pressure, thereby obtaining 0.15 g of the compound represented by Formula 1-4. The NMR results obtained for the prepared compound are as follows, which show that the compound represented by Formula 1-4 was prepared. NMR results: 1H NMR, 0.94 (6H), 1.81 (1H), 3.30 (2H), 8.01 (1H).

A CMP slurry composition was prepared in the same manner as in Example 1, except that the type and content of each component of the composition were changed as listed in Table 1.

Examples 5

After dissolving 0.084 g (0.001 mol) of 3-amino-1,2,4-triazole in 100 g of distilled water, 0.101 g (36 wt%, 0.001 mol) of HCl was added to the solution, which was then vigorously stirred in an ice water bath at 0°C to 5°C. Thereafter, 1.3 g (5 wt%, 0.001 mol) of NaNO ₂ was slowly added dropwise thereto, and the resulting product was stirred and allowed to stand for 1 hour to prepare an azo salt. After dissolving 0.088 g (0.001 mmol) of amylamine in 100 g of ultrapure water, 4 g of a 2.5 M NaOH aqueous solution was added to the solution, which was then added dropwise to the reactor containing the azo salt for 30 minutes. Thereafter, the obtained product was stirred and allowed to stand for 1 hour, and then dried under reduced pressure, thereby obtaining 0.162 g of the compound represented by Formula 1-5. The NMR results obtained for the prepared compound are as follows, which show that the compound represented by Formula 1-5 was prepared. NMR results: 1H NMR, 0.87 (3H), 1.22-1.42 (4H), 1.69 (2H), 3.61 (2H), 8.01 (1H).

A CMP slurry composition was prepared in the same manner as in Example 1, except that the type and content of each component of the composition were changed as listed in Table 1.

Examples 6

After dissolving 0.084 g (0.001 mol) of 3-amino-1,2,4-triazole in 100 g of distilled water, 0.101 g (36 wt%, 0.001 mol) of HCl was added to the solution, which was then vigorously stirred in an ice water bath at 0°C to 5°C. Thereafter, 1.3 g (5 wt%, 0.001 mol) of NaNO ₂ was slowly added dropwise thereto, and the resulting product was stirred and allowed to stand for 1 hour to prepare an azo salt. After dissolving 0.088 g (0.001 mmol) of isoamylamine in 100 g of ultrapure water, 4 g of a 2.5 M NaOH aqueous solution was added to the solution, which was then added dropwise to the reactor containing the azo salt for 30 minutes. Thereafter, the resulting product was stirred and allowed to stand for 1 hour, followed by drying under reduced pressure, thereby obtaining 0.162 g of the compound represented by Formula 1-6. The NMR results obtained for the prepared compound are as follows, which show that the compound represented by Formula 1-6 was prepared. NMR results: 1H NMR, 0.88 (6H), 1.43-1.60 (3H), 3.63 (2H), 8.01 (1H).

A CMP slurry composition was prepared in the same manner as in Example 1, except that the type and content of each component of the composition were changed as listed in Table 1.

Comparison Examples 1 To compare examples 3

A CMP slurry composition was prepared in the same manner as in Example 1, except that the type and content of each component of the composition were changed as listed in Table 1.

Each of the CMP slurry compositions prepared in Examples 1 to 6 and Comparative Examples 1 to 3 was evaluated according to the properties shown in Table 1. The results are shown in Table 1.

(1) Copper film polishing rate (unit: angstroms/minute):

A blanket wafer (diameter: 300 mm) having a copper film formed on a silicon oxide film was polished under the following conditions, and then the change in sheet resistance before and after polishing was converted into an etched thickness, thereby calculating the polishing rate.

Grinding equipment: Reflexion LK 300 mm (AMAT Co., Ltd.)

Grinding pad: IC1000

Polishing Time: Polishing time varies depending on the amount of polishing of the blanket wafer.

Head speed per minute: 87 rpm

Press plate speed per minute: 98 rpm

Flow rate: 200 ml/min

Pressure: 1.0 psi

Measurement of polishing rate: using a sheet resistance meter.

(2) Erosion (unit: nanometer): The polishing solution was allowed to stand at 60°C for 1 hour. After polishing the patterned wafer under the same conditions as in (1), the profile of the wafer pattern was measured using an atomic force profiler (InSight CAP, Bruker Co., Ltd.). The erosion was calculated based on the height difference between the surrounding oxide film and the unit oxide film in the 0.18 µm × 0.18 µm patterned area of the polished wafer. Here, the scanning rate was set to 100 μm/s and the scanning length was set to 2 mm.

Table 1 Examples Comparison Examples 1 2 3 4 5 6 1 2 3 Abrasives 0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 0.33 Corrosion Inhibitor 1 Formula 1-1 0.02 - - - - - - - - Formula 1-2 - 0.02 - - - - - - - Formula 1-3 - - 0.02 - - - - - - Formula 1-4 - - - 0.03 - - - - - Formula 1-5 - - - - 0.03 - - - - Formula 1-6 - - - 0.03 - - - Corrosion Inhibitor 2 3,5-Diamino-1,2,4-triazole - - - - - 0.03 0.02 - - 5-Methylbenzotriazole - - - - - - - 0.02 - 1,2,4-Triazole - - - - - - - - 0.02 Chelating agents 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 1.3 Oxidants 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 Ultrapure water The rest The rest The rest The rest The rest The rest The rest The rest The rest Total 100 100 100 100 100 100 100 100 100 Copper film polishing rate 2743 2868 2888 2911 2838 2996 2650 1610 2890 Erosion twenty three twenty two twenty three twenty one 25 twenty three 35 37 31

As can be seen from Table 1, the CMP slurry composition according to the present invention provides improved planarity of the polished surface by reducing surface defects (e.g., erosion) without sacrificing high polishing rates with respect to copper films.

In contrast, the CMP slurry composition according to the comparative example of the present invention not containing the compound represented by Formula 1 fails to provide improved flatness of the polished surface and increased polishing rate with respect to the copper film.

It should be understood that various modifications, changes, alterations and equivalent embodiments may be made by those skilled in the art without departing from the spirit and scope of the present invention.

without

without.

without.

Claims (6)

A CMP slurry composition for grinding copper, comprising: at least one solvent selected from polar solvents and non-polar solvents; 0.001 wt % to 20 wt % of abrasive; 0.001 wt % to 5 wt % of corrosion inhibitor; 0.01 wt % to 10 wt % of chelating agent; and 0.1 wt % to 5 wt % of oxidizing agent, wherein the corrosion inhibitor comprises a compound represented by Formula 1 or a salt thereof,

wherein _R1 and _R2 are each independently hydrogen, substituted or unsubstituted straight or branched _C1 to _C5 alkyl, or substituted or unsubstituted _C6 to _C10 aryl; _R3 is hydrogen or substituted or unsubstituted straight or branched _C1 to _C3 alkyl; and _R4 is substituted or unsubstituted straight or branched _C1 to _C5 alkyl, substituted or unsubstituted straight or branched _C2 to _C5 alkenyl, or substituted or unsubstituted straight or branched _C2 to _C5 alkynyl. The CMP slurry composition for polishing copper as claimed in claim 1, wherein the compound represented by Formula 1 is a compound represented by one of Formulas 1-1 to 1-6,

A CMP slurry composition for polishing copper as described in claim 1, wherein the corrosion inhibitor further includes a corrosion inhibitor other than the compound represented by Formula 1. The CMP slurry composition for polishing copper as described in claim 3, wherein the corrosion inhibitor other than the compound represented by Formula 1 includes at least one selected from a triazole corrosion inhibitor and a tetrazole corrosion inhibitor. The CMP slurry composition for grinding copper as described in claim 1 includes: the solvent is present in the CMP slurry composition in its remaining amount. A method for grinding copper, comprising: grinding a copper film using the CMP slurry composition for grinding copper as described in any one of claims 1 to 5.