Slurry composition for polishing metal film

Abstract

The present invention relates to a slurry composition for polishing a metal film, the composition comprising an abrasive, an oxidizing agent, and an oxidizing catalyst. According to the present invention, an iron-malonate complex compound used as an oxidizing catalyst shows a higher energy state when compared with a conventional iron-complex compound, that is, a complex compound in which an iron ion is coordinated with water or hydroxyl groups, and thus reacts with a peroxide as an oxidizing agent to promote a radical formation reaction. Therefore, the polishing composition using the iron-malonate complex compound as an oxidizing catalyst can increase the formation of radicals to enhance the polishing rate.

Description

Slurry composition for polishing metal films

[0001] The present invention relates to a polishing slurry composition, and more particularly, to a metal film polishing slurry composition.

[0002] Semiconductors, as they are called integrated circuits, are a technology that involves stacking microcircuits one after another, and their quality is key. Therefore, ensuring a flat wafer surface is crucial. To achieve this, a chemical mechanical planarization (CMP) process is used. This CMP process flattens each layer on the wafer, improving the shape and positional precision of subsequent patterns across the entire wafer.

[0003] The above chemical-mechanical planarization process requires a polishing slurry. Polishing slurries capable of polishing metal films generally require an oxidizing agent capable of oxidizing the surface of the metal film. Furthermore, metal ion catalysts were used as oxidation catalysts to facilitate the oxidizing action of the oxidizing agent, but the desired polishing rate was not achieved.

[0004] Accordingly, there is a continuing demand for new polishing slurry compositions that can improve productivity with high polishing speeds.

[0005] Therefore, the problem to be solved by the present invention is to provide a slurry composition for polishing a metal film having an excellent metal polishing speed.

[0006] The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0007] In order to achieve the above technical task, one aspect of the present invention provides a slurry composition for polishing a metal film. The slurry composition for polishing a metal film comprises a solvent; an abrasive; an oxidizing agent; and an oxidation catalyst, wherein the oxidation catalyst comprises an iron-malonate complex.

[0008] The above iron-malonate complex is Fe(III)(C3H2O4) x (OH) 6-2x , or Fe(II)(C3H2O4) x (OH) 6-2x (x is an integer from 1 to 3) can be selected from the group consisting of.

[0009] The above iron-malonate complex may be Fe(III)(C3H2O4)2(OH)2 or Fe(II)(C3H2O4)2(OH)2.

[0010] The above iron-malonate complex has a COO peak area greater than the Fe-OH peak area in the O1s X-ray photoelectron spectroscopy (XPS) graph. - It is characterized by a larger peak area.

[0011] The above iron-malonate complex is characterized by showing Fe-OC peaks, Fe-OH peaks, and Fe-O=C peaks in an X-ray absorption spectroscopy (XAS) graph.

[0012] The above oxidation catalyst may be included in an amount of 0.00025 mol to 2.5 mol per 100 g of solvent in the slurry composition for polishing a metal film.

[0013] The abrasive may include metal oxides, metal nitrides, metal oxynitrides and mixtures thereof.

[0014] The above abrasive may be included in an amount of 0.0001 wt% to 10 wt% per 100 g of solvent in the slurry composition for polishing a metal film.

[0015] The above oxidizing agent may be selected from the group consisting of hydrogen peroxide, periodic acid, periodate salt, perbromic acid, perbromate salt, perchloric acid, perborate salt, and permanganate.

[0016] The above oxidizing agent may be included in an amount of 0.003 mol to 30 mol per 100 g of solvent in the slurry composition for polishing a metal film.

[0017] The above metal film polishing slurry composition may further contain glycine.

[0018] The above metal film polishing slurry composition may further include a pH adjuster.

[0019] In addition, another aspect of the present invention provides a method for preparing the slurry composition for polishing a metal film. The method for preparing the slurry composition for polishing a metal film includes the steps of: preparing a first reaction solution by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent; preparing a second reaction solution by adding glycine to the first reaction solution and adjusting the pH to a basic level to form an iron-glycine complex; preparing a third reaction solution by adding malonic acid to the second reaction solution to form malonic acid decomposed into malonate; and preparing a slurry composition for polishing a metal film by adjusting the pH of the third reaction solution to an acid level to form an iron-malonate complex.

[0020] The above iron ion salt may be a trivalent iron ion salt or a divalent iron ion salt.

[0021] The above trivalent iron ion salts are iron sucrose, iron(III) oxide, iron(III) acetate, iron(III) sulfate, lithium iron(III) oxide, iron(III) phosphate, iron(III) pyrophosphate, iron(III) ionophore IV, ammonium iron(III) hexacyanoferrate(II), iron(III) ferrocyanide, iron(III) i-propoxide, iron(III) oxo acetate perchlorate perchlorate), ammonium iron(III) citrate, iron(III) dicarbonate, iron(III) acetylacetonate, iron(III) bromide, iron(III) chloride, iron(III) arsenide, iron(III) oxalate, ammonium iron(III) oxalate, iron(III) fluoride, iron(III) iodide, iron(III) nitrate, iron(III) phthalocyanine chloride,It may include at least one selected from the group consisting of iron(III) perchlorate, iron(III) sulfate, ammonium iron(III) sulfate, and iron(III) tartrate.

[0022] The above divalent iron ion salts are iron(II) oxide, iron(II) acetate, iron(II) sulfate, lithium iron(II) oxide, iron(II) phosphate, iron(II) pyrophosphate, iron(II) ionophore IV, ammonium iron(II) hexacyanoferrate(II), iron(II) ferrocyanide, iron(II) i-propoxide, iron(II) oxo acetate perchlorate, ammonium iron(II) Ammonium iron(II) citrate, iron(II) dicarbonate, iron(II) acetylacetonate, iron(II) bromide, iron(II) chloride, iron(II) arsenide, iron(II) oxalate, ammonium iron(II) oxalate, iron(II) fluoride, iron(II) iodide, iron(II) nitrate, iron(II) phthalocyanine chloride, iron(II) perchlorate, iron(II) iron(II) sulfate,It may include at least one selected from the group consisting of ammonium iron(II) sulfate and iron(II) tartrate.

[0023] The above alkalinity may have a pH of 10 to 11, and the above acidity may have a pH of 2 to 3.

[0024] According to the present invention, since the iron-malonate complex is used as an oxidation catalyst, it exhibits a higher energy state compared to conventional iron-complexes, i.e., complexes in which iron ions are coordinated with water or hydroxyl groups, and thus reacts with peroxide, which is an oxidizing agent, to promote a radical formation reaction, and thus, a polishing composition using the iron-malonate complex as an oxidation catalyst can improve a polishing speed by increasing the generation of radicals.

[0025] However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

[0026] Figure 1 is a diagram showing the energy state of an iron-complex compound according to the present invention.

[0027] Figure 2 is a flow chart showing a method for manufacturing a slurry composition for polishing a metal film according to one embodiment of the present invention.

[0028] FIG. 3 is a spectrum showing Raman analysis of a slurry composition for polishing a metal film according to a comparative example and an embodiment of the present invention.

[0029] FIG. 4 is a spectrum showing the XPS analysis of O1s and C1s of a slurry composition for polishing a metal film according to a comparative example and an embodiment of the present invention.

[0030] FIG. 5 is a spectrum showing XAS analysis of a slurry composition for polishing a metal film according to a comparative example and an embodiment of the present invention.

[0031] FIG. 6 is a graph showing the polishing speed of polishing slurries according to one embodiment and a comparative example of the present invention for a tungsten wafer.

[0032] Hereinafter, to explain the present invention in more detail, preferred embodiments according to the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. In the drawings, when a layer is referred to as being "on" another layer or substrate, it may be formed directly on the other layer or substrate, or a third layer may be interposed therebetween.

[0033]

[0034] Slurry composition for polishing metal films

[0035] One aspect of the present invention provides a slurry composition for polishing a metal film. The slurry composition for polishing a metal film according to one embodiment of the present invention comprises a solvent, an abrasive, an oxidizing agent, and an oxidation catalyst.

[0036] The above solvent serves to disperse the components of the slurry composition for metal film polishing so that each component can be easily mixed, and water, specifically ultrapure water or deionized water, can be used, but is not limited thereto.

[0037] The abrasive may include a metal oxide, a metal nitride, a metal oxynitride, and a mixture thereof, and specifically, may be a metal oxide selected from the group consisting of silica (for example, colloidal silica or fumed silica), ceria, alumina, titania, zirconia, and germania. Preferably, it may be silica, specifically colloidal silica. Unlike a ceria abrasive, such a silica abrasive can suppress agglomeration when used together with an oxidizing agent. The abrasive may be contained in an amount of 0.0001 wt% to 10 wt%, specifically 0.2 wt% to 5 wt%, and more specifically 1 wt% to 3 wt%, based on 100 g of a solvent in a slurry composition for polishing a metal film. The abrasive may be a spherical particle having an average diameter of about 10 to 100 nm.

[0038] The above oxidizing agent may be a peroxide, which is a substance that oxidizes the surface of the metal film into a soft metal oxide, thereby facilitating mechanical polishing with a polishing pad to remove the metal film. The peroxide may generate reactive radicals, such as hydroxyl radicals (·OH) or hydroperoxyl radicals (·OOH), thereby easily oxidizing the surface of the metal film. The peroxide may be, for example, hydrogen peroxide, periodic acid, periodate salt, perbromic acid, perbromate salt, perchloric acid, perborate salt, and permanganate, or a compound containing them. In one specific example, the peroxide may be hydrogen peroxide. The above oxidizing agent may be contained in an amount of 0.003 mol to 30 mol, specifically 3 mol to 20 mol, per 100 g of solvent in the slurry composition for polishing a metal film.

[0039] The above oxidation catalyst is a substance that promotes the conversion of the oxidizing agent, peroxide, into radicals. These radicals have very high metal oxidizing power. That is, the higher the effectiveness of the oxidation catalyst for decomposing the oxidizing agent, the more radical production there is, which enhances the surface oxidation effect and can improve the polishing speed. The present invention is characterized by including an iron-malonate complex as such an oxidation catalyst.

[0040] Figure 1 is a diagram showing the energy state of an iron-complex compound according to the present invention.

[0041] Referring to FIG. 1, the higher the energy state of the Fe ion, the more it can promote a reaction to form a radical by reacting with a peroxide. Since the iron-malonate complex compound according to the present invention exhibits a higher energy state compared to a complex compound coordinated with water or a hydroxyl group, it promotes a reaction to form a radical by reacting with a peroxide, and thus, when the iron-malonate complex compound is used as an oxidation catalyst, the polishing speed can be improved by increasing the generation of radicals.

[0042] The above oxidation catalyst may be an iron-malonate complex formed by coordination bonding of malonate to a trivalent or divalent iron ion hydrate. Specifically, the iron-malonate complex is Fe(III)(C3H2O4). x (OH) 6-2x , or Fe(II)(C3H2O4) x (OH) 6-2x (x may be an integer from 1 to 3). Specifically, x may be 2. That is, the iron-malonate complex may be Fe(III)(C3H2O4)2(OH)2 or Fe(II)(C3H2O4)2(OH)2.

[0043] The above iron-malonate complex has a COO peak area greater than the Fe-OH peak area in the O1s X-ray photoelectron spectroscopy (XPS) graph. -It is characterized by a larger peak area.

[0044] The above iron-malonate complex is characterized by showing Fe-OC peaks, Fe-OH peaks, and Fe-O=C peaks in an X-ray absorption spectroscopy (XAS) graph.

[0045] Such oxidation catalysts may be included in an amount of 0.00025 mol to 2.5 mol per 100 g of solvent in the slurry composition for polishing a metal film.

[0046] The above metal film polishing slurry composition may further contain glycine.

[0047] The above metal film polishing slurry composition may further contain a pH adjuster. The pH adjuster may be TMAH (Tetramethylammonium hydroxide), KOH, NaOH, NH4OH, HCl, HNO3, H2SO4, or H3PO4. The pH of the metal film polishing slurry composition may be adjusted to a range of 2.0 to 9.0, and for example, the pH may be adjusted to 2.0 to 2.5.

[0048] The above metal film polishing slurry composition may include a diluent, and the diluent may be water, preferably ultrapure water or deionized water.

[0049] The above metal film polishing slurry composition may further include one or more additives selected from the group consisting of a dispersant, a surfactant, a polishing inhibitor, a leveling agent, a slurry stabilizer, and a chelating agent.

[0050] The metal film polishing slurry composition may have a polishing rate of 500 Å / min or more for a tungsten wafer. Specifically, the metal film polishing slurry composition according to one embodiment of the present invention includes iron malonate as an oxidation catalyst in addition to the polishing agent and the oxidizing agent, thereby exhibiting a polishing rate of 500 Å / min or more, specifically 588 Å / min, for a tungsten wafer, thereby exhibiting a significantly improved polishing rate compared to a case in which there is no additive (50 to 60 Å / min) and a case in which iron ions are included as an oxidation catalyst but an iron malonate complex is not formed (about 300 Å / min). In addition, the metal film polishing slurry composition may improve the polishing rate of not only the tungsten wafer but also other metal films such as Cu and SiC.

[0051]

[0052] Method for producing a slurry composition for polishing a metal film

[0053] In addition, another aspect of the present invention provides a method for preparing a slurry composition for polishing a metal film.

[0054] Figure 2 is a flow chart showing a method for manufacturing a slurry composition for polishing a metal film according to one embodiment of the present invention.

[0055] Referring to FIG. 2, the method for manufacturing the metal film polishing slurry composition is

[0056] A step of preparing a first reaction solution by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent;

[0057] A step of adding glycine to the first reaction solution and adjusting the pH to alkaline to prepare a second reaction solution in which an iron-glycine complex is formed;

[0058] A step of adding malonic acid to the second reaction solution to prepare a third reaction solution in which malonic acid is decomposed into malonate; and

[0059] It includes a step of preparing a metal film polishing slurry composition in which an iron-malonate complex is formed by adjusting the pH of the third reaction solution to acidity.

[0060]

[0061] Hereinafter, a method for manufacturing a slurry composition for polishing a metal film according to the present invention will be described in detail step by step.

[0062] First, a first reaction solution is prepared by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent.

[0063] Since the solvent, abrasive and oxidizer are the same as those described above in [Slurry composition for polishing metal film], detailed descriptions are omitted to avoid redundant description.

[0064] The above iron ion salt serves as an iron ion source for producing an iron-malonate complex used as an oxidation catalyst, and a trivalent iron ion salt or a divalent iron ion salt can be used.

[0065] At this time, the trivalent iron ion salts include iron sucrose, iron(III) oxide, iron(III) acetate, iron(III) sulfate, lithium iron(III) oxide, iron(III) phosphate, iron(III) pyrophosphate, iron(III) ionophore IV, ammonium iron(III) hexacyanoferrate(II), iron(III) ferrocyanide, iron(III) i-propoxide, and iron(III) oxo acetate perchlorate. perchlorate), ammonium iron(III) citrate, iron(III) dicarbonate, iron(III) acetylacetonate, iron(III) bromide, iron(III) chloride, iron(III) arsenide, iron(III) oxalate, ammonium iron(III) oxalate, iron(III) fluoride, iron(III) iodide, iron(III) nitrate, iron(III) phthalocyanine chloride,It may include at least one selected from the group consisting of iron(III) perchlorate, iron(III) sulfate, ammonium iron(III) sulfate and iron(III) tartrate, and the divalent iron ion salt may include iron(II) oxide, iron(II) acetate, iron(II) sulfate, lithium iron(II) oxide, iron(II) phosphate, iron(II) pyrophosphate, iron(II) ionophore IV, ammonium iron(II) hexacyanoferrate(II) iron(II) hexacyanoferrate(II)), iron(II) ferrocyanide, iron(II) i-propoxide, iron(II) oxo acetate perchlorate, ammonium iron(II) citrate, iron(II) dicarbonate, iron(II) acetylacetonate, iron(II) bromide, iron(II) chloride, iron(II) arsenide, iron(II) oxalate, ammonium iron(II) oxalate, iron(II) fluoride (iron(II) fluoride),It may include at least one selected from the group consisting of iron(II) iodide, iron(II) nitrate, iron(II) phthalocyanine chloride, iron(II) perchlorate, iron(II) sulphate, ammonium iron(II) sulphate, and iron(II) tartrate.

[0066] The above glycine forms a complex with the iron ion salt, thereby preventing the subsequent hydroxide formation of the iron ion and acting as a precursor forming agent to facilitate the complex formation reaction with malonate. At this time, the above glycine forms a complex with the iron ion under basic conditions, so it is preferable to adjust the pH of the first reaction solution to basicity in the subsequent step. The abrasive and oxidizing agent are not affected by pH.

[0067]

[0068] Next, adjust the pH of the first reaction solution to alkaline.

[0069] As described above, in order to form a complex by reacting the glycine with an iron ion salt, the pH of the reaction solution must be basic. Accordingly, the pH of the first reaction solution containing the glycine and the iron ion salt is adjusted to be basic, for example, pH 10 to 11. The pH adjustment can be performed by using a basic pH additive, and specifically, TMAH (TetraMethylAmmonium Hydroxide), KOH, NaOH, or NH4OH can be used as the basic pH additive, but is not limited thereto.

[0070] By adjusting the pH of the first reaction solution to an alkaline pH, a second reaction solution is prepared in which glycine and an iron ion salt react to form an iron-glycine complex. Accordingly, the second reaction solution includes an abrasive, an oxidizing agent, and an iron-glycine complex.

[0071]

[0072] Next, malonic acid is added to the second reaction solution to form a third reaction solution.

[0073] The above malonic acid plays a role in providing malonate in the iron-malonate complex. The above malonic acid decomposes in the basic region to form COO - It forms a malonate with an ion. Specifically, the iron-malonate complex is formed when malonic acid decomposes and becomes malonate, coordinating with an iron ion. However, the pKa for malonic acid to become malonate is 5.70, and at a pH below that, it exists in the COOH form, making it difficult to form a complex.

[0074] Meanwhile, at basic pH, malonic acid decomposes to form malonate, but since iron ions are hydroxylated and precipitated, it is difficult to form an iron-malonate complex at basic pH alone. Therefore, to prevent hydroxylation of iron ions, a method can be performed in which a complex is first formed with glycine in a basic region and then coordinated with malonate.

[0075] Accordingly, the third reaction solution contains an abrasive, an oxidizing agent, an iron-glycine complex, and a malonate.

[0076]

[0077] Next, the pH of the third reaction solution, which is basic, is adjusted to acidic.

[0078] The above acidic region can be adjusted to pH 2 to 3. The pH can be adjusted by using an acidic pH additive, and specifically, HCl, HNO3, H2SO4, or H3PO4 can be used as the acidic pH additive, but is not limited thereto.

[0079] COO of malonate in the third reaction solution - As the ion moves to the acidic region, it does not attach to a proton, but reacts with iron-glycine, displacing glycine to form an iron-malonate complex. This can be confirmed by Raman analysis and XPS analysis described below.

[0080] The resulting slurry composition comprises an abrasive, an oxidizing agent, glycine and an iron-malonate complex.

[0081]

[0082] According to the present invention, since the iron-malonate complex is used as an oxidation catalyst, it exhibits a higher energy state compared to conventional iron-complexes, i.e., complexes in which iron ions are coordinated with water or hydroxyl groups, and thus reacts with peroxide, which is an oxidizing agent, to promote a radical formation reaction, and thus, a polishing composition using the iron-malonate complex as an oxidation catalyst can improve a polishing speed by increasing the generation of radicals.

[0083] Below, preferred experimental examples are presented to aid in understanding the present invention. However, the following experimental examples are provided solely to aid in understanding the present invention, and the present invention is not limited to the following experimental examples.

[0084]

[0085] Preparation examples and comparative examples of slurry compositions for metal film polishing

[0086] [Manufacturing example]

[0087] An iron ion solution containing 2.5 wt% of silica having a particle size of 30 nm as an abrasive, 3 mol of hydrogen peroxide as an oxidizing agent, and 0.22 mol of Fe(Ⅲ) ion salt in the form of a nitrate as a catalyst was prepared for 100 g of ultrapure water, and then 6.7 mol of glycine was added and the pH was adjusted to 10 to form an iron-glycine complex, and then 4.8 mol of malonic acid was added and the pH was adjusted to 2.3 to form an iron-malonate complex by substituting malonate for the glycine site, thereby preparing a metal film polishing slurry composition.

[0088]

[0089] [Comparative Example 1]

[0090] In the composition of the above manufacturing example, a slurry composition was prepared by titrating the abrasive at pH 2.3 without adding hydrogen peroxide, iron ion salt, malonic acid, and glycine.

[0091]

[0092] [Comparative Example 2]

[0093] After stabilizing the composition of Comparative Example 1 by titrating to pH 10, the composition was titrated again to pH 2.3 to prepare a slurry composition.

[0094]

[0095] [Comparative Example 3]

[0096] In the composition of Comparative Example 1, 3 mol (mol) of hydrogen peroxide and 0.22 mol (mol) of iron ion salt were further added to 100 g of the solution to prepare a slurry composition.

[0097]

[0098] [Comparative Example 4]

[0099] In the composition of Comparative Example 3, the pH was adjusted to 10 to stabilize, and then adjusted again to pH 2.3 to prepare a slurry composition.

[0100]

[0101] [Comparative Example 5]

[0102] A slurry composition was prepared by adding 4.8 mol of malonic acid to the composition of Comparative Example 3.

[0103]

[0104] [Comparative Example 6]

[0105] After stabilizing the composition of Comparative Example 3 by adjusting the pH to 10, 4.8 mol of malonic acid was added and the pH was adjusted again to 2.3 to prepare a slurry composition.

[0106]

[0107] [Comparative Example 7]

[0108] A slurry composition was prepared by adding 6.7 mol of glycine to the composition of Comparative Example 3.

[0109]

[0110] [Comparative Example 8]

[0111] In the composition of Comparative Example 3, 6.7 mol of glycine was further added to stabilize the pH at 10, and then the pH was titrated again to 2.3 to prepare a slurry composition.

[0112]

[0113] [Comparative Example 9]

[0114] A slurry composition was prepared by titrating the composition of the above manufacturing example at pH 2.3.

[0115]

[0116] The composition and pH of the metal film polishing slurry composition manufactured in the above manufacturing examples and comparative examples are summarized in Table 1 below.

[0117] Slurry composition for polishing metal film (based on 100 g of solvent)Polishing speed [Å / min]Polishing agent (% by weight)H2O2(mol)Fe(NO3)3(mol)Glycine(mol)Malonic acid(mol)pH titrationFe-malonate formationComparative example 12.5----2.3X54Comparative example 22.5----10→2.3X60Comparative example 32.530.22--2.3X303Comparative example 42.530.22--10→2.3X288Comparative example 52.530.22-4.82.3X321Comparative example 62.530.22-4.810→2.3X306Comparative example 72.530.226.7-2.3X315Comparative example 82.530.226.7-10→2.3X318Comparative example 92.530.226.74.82.3X309Manufacturing example 2.530.226.74.810→2.3O588

[0118] [Experimental Example 1: Analysis of the Formation of Iron-Malonate in a Slurry Composition for Metal Film Polishing]

[0119] In order to determine whether iron-malonate is formed through addition of malonic acid and glycine and pH adjustment in the slurry composition for metal film polishing according to the present invention during the composition preparation process, the spectrum for OH bend, COO- and COOH peaks was measured through Raman analysis for various slurry compositions, and the results are shown in Fig. 3.

[0120] FIG. 3 is a spectrum showing Raman analysis of a slurry composition for polishing a metal film according to a comparative example and an embodiment of the present invention.

[0121] At this time, MGF10-2.3 refers to a case where the polishing slurry composition includes malonic acid (M), glycine (G), and iron ions (Fe), and the pH is adjusted to 2.3 after being titrated to 10, MGF10 refers to a case where the pH is adjusted to 10 only, and MGF2.3 refers to a case where the pH is adjusted to 2.3 only.

[0122] Additionally, when only malonic acid and iron ions were added to the polishing composition, it was designated as MF.

[0123] As shown in Fig. 3, in the OH bend, in the acidic region, the OH bend due to malonic acid appears, but in the case of MGF10-2.3, the OH bend did not appear compared to MGF2.3. This is because, as shown in the right drawing of Fig. 3, in the case of MGF 10-2.3, COO - This is because as it moves into the acidic region, protons do not attach and form a chelate structure.

[0124] In addition, in the COOH peak region, the COOH peak that appears in the acid appears in MF2.3 and MGF 2.3, but in the case of MGF10-2.3, the COOH peak did not appear. From this, it is concluded that the carboxylate (COO) of malonate produced by decomposition of malonic acid in the base - , 1640 cm -1 ) It can be seen that the structure is partially maintained even in the acidic region (pH 2.3), and it can be seen that the iron-malonate complex structure is better formed than when malonic acid alone is added without glycine due to the synergistic effect with glycine in an acidic atmosphere.

[0125]

[0126] In addition, in order to determine whether iron-malonate was formed depending on whether pH was adjusted in the same MGF composition, XPS analysis and XAS analysis were performed, and the results are shown in FIGS. 4 and 5, respectively.

[0127] FIG. 4 is a spectrum showing the XPS analysis of O1s and C1s of a slurry composition for polishing a metal film according to a comparative example and an embodiment of the present invention.

[0128]

[0129] As shown in Fig. 4, when malonic acid (M), glycine (G), and iron ion (Fe) were added to the slurry composition for polishing a metal film according to the present invention and the pH was adjusted to a basic state and then controlled to an acidic state (MGF10-2.3) and when the pH was immediately adjusted to 2.3 (MGF2.3), the O1s peak showed COO in the case of the pH adjusted to a basic state and then controlled to an acidic state (MGF10-2.3) according to the present invention. - It was confirmed that more peaks were detected.

[0130] In addition, in the case of the C1s peak, the area of ​​the CO-Fe peak increased when the pH was controlled to acidic after being titrated to basic according to the present invention (MGF10-2.3), so it can be seen that an Fe-malonate complex was formed when the pH was controlled to acidic after being titrated to basic according to the present invention (MGF10-2.3).

[0131]

[0132] FIG. 5 is a spectrum showing XAS analysis of a slurry composition for polishing a metal film according to a comparative example and an embodiment of the present invention.

[0133] According to the present invention, when malonic acid (M), glycine (G), and iron ion (Fe) are added to a slurry composition for polishing a metal film, and the pH is adjusted to a basic pH and then controlled to an acidic pH (MGF10-2.3) and when the pH is immediately adjusted to 2.3 (MGF2.3), the complex ion bonding distance of the formed Fe complex can be determined by comparing the results using XAS.

[0134] As shown in Fig. 5, when the pH was directly adjusted to 2.3 (MGF 2.3), only the Fe-OH peak appeared, but when the pH was controlled to basicity and acidity according to the present invention, it was confirmed that the Fe-OC peak and the Fe-O=C peak appeared, and through this, it was confirmed that a malonate complex was formed.

[0135] In addition, when the areas of the corresponding peaks are compared, the ratio of Fe-OH and Fe-OC is shown to be almost 1:1, which can be inferred that the ratio of Fe-OC: Fe-O=C: Fe-OH is 1:1:1. This means that out of the six ligand adsorption sites in total, two Fe-OC coordination bonds, two Fe-O=C coordination bonds, and two Fe-OH coordination bonds are occupied by Fe, which is inferred to mean that two malonate complex ions are adsorbed on Fe, and two OH groups are adsorbed.

[0136]

[0137] [Experimental Example 2: Measurement of polishing rate of chemical mechanical polishing (CMP) using a slurry composition for metal film polishing]

[0138] Each of the various polishing slurry compositions manufactured in the above manufacturing examples and comparative examples was used as a polishing slurry to perform chemical mechanical polishing (CMP) on a tungsten wafer. The CMP device used was Poli 300 from G&P, the CMP polishing pad used was IC1010 from Dow Chemical, the rotation speed of the polishing pad was 83 rpm, the rotation speed of the table on which the wafer was placed was 97 rpm, the pressure applied by the polishing pad was 4 psi, and the flow rate of the polishing slurry was 200 ml / min.

[0139] The polishing rate was calculated by measuring the thickness before and after polishing of each tungsten wafer, and the results are shown in Table 1 and Fig. 6.

[0140] FIG. 6 is a graph showing the polishing speed of polishing slurries according to one embodiment and a comparative example of the present invention for a tungsten wafer.

[0141] As shown in Table 1 and Fig. 6, when the polishing slurry contained only an abrasive without any other additives, the polishing rate was low at 50-60 Å / min, but when the oxidizing agent and oxidation catalyst contained iron ions, a mixture of iron ions and malonic acid, or a mixture of iron ions and glycine, the iron-malonate complex was not formed, and the polishing rate increased slightly, showing about 300 Å / min regardless of the pH. However, when the oxidizing agent contained iron ions, malonic acid, and glycine as oxidation catalysts, and the pH was first adjusted to basic pH and then controlled to acidic pH (MGF10->2.3), iron-malonate was formed, and the polishing rate was 588 Å / min, which was confirmed to be a significant increase of about 10 times or more compared to the case without any additives and about 2 times compared to the case containing only malonic acid and glycine.

[0142] Therefore, the slurry composition for polishing a metal film according to the present invention uses an iron-malonate complex as an oxidation catalyst in addition to the polishing agent and the oxidizing agent, and thus exhibits a higher energy state compared to a conventional iron-complex, i.e., a complex compound in which iron ions are coordinated with water or a hydroxyl group, and thus reacts with a peroxide, which is an oxidizing agent, to promote a radical formation reaction, and thus, the polishing composition using an iron-malonate complex as an oxidation catalyst can improve the polishing speed by increasing the generation of radicals.

[0143]

[0144] Above, the present invention has been described in detail with reference to preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications and changes can be made by those skilled in the art within the technical spirit and scope of the present invention.

Claims

1. Solvent; abrasive; oxidizer; and Including an oxidation catalyst, The above oxidation catalyst comprises an iron-malonate complex compound. Slurry composition for polishing metal films.

2. In paragraph 1, The above iron-malonate complex is Fe(III)(C3H2O4) x (OH) 6-2x , or Fe(II)(C3H2O4) x (OH) 6-2x A slurry composition for polishing a metal film, characterized in that (x is an integer from 1 to 3).

3. In paragraph 2, A slurry composition for polishing a metal film, characterized in that the iron-malonate complex is Fe(III)(C3H2O4)2(OH)2 or Fe(II)(C3H2O4)2(OH)2.

4. In paragraph 1, The above iron-malonate complex has a COO peak area greater than the Fe-OH peak area in the O1s X-ray photoelectron spectroscopy (XPS) graph. - A slurry composition for polishing a metal film, characterized by a larger peak area.

5. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the iron-malonate complex compound exhibits Fe-OC peaks, Fe-OH peaks, and Fe-O=C peaks in an X-ray absorption spectroscopy (XAS) graph.

6. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the oxidation catalyst is contained in an amount of 0.00025 mol to 2.5 mol per 100 g of solvent in the slurry composition for polishing a metal film.

7. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the abrasive comprises a metal oxide, a metal nitride, a metal oxynitride, and a mixture thereof.

8. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the abrasive is contained in an amount of 0.0001 wt% to 10 wt% with respect to 100 g of solvent in the slurry composition for polishing a metal film.

9. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the oxidizing agent is selected from the group consisting of hydrogen peroxide, periodic acid, periodate salt, perbromic acid, perbromate salt, perchloric acid, perborate salt, and permanganate.

10. In paragraph 1, A slurry composition for polishing a metal film, characterized in that the oxidizing agent is contained in an amount of 0.003 mol to 30 mol per 100 g of solvent in the slurry composition for polishing a metal film.

11. In paragraph 1, A metal film polishing slurry composition, characterized in that the metal film polishing slurry composition further comprises glycine.

12. In paragraph 1, A metal film polishing slurry composition, characterized in that the metal film polishing slurry composition further comprises a pH adjusting agent.

13. A step of preparing a first reaction solution by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent; A step of adding glycine to the first reaction solution and adjusting the pH to alkaline to prepare a second reaction solution in which an iron-glycine complex is formed; A step of adding malonic acid to the second reaction solution to prepare a third reaction solution in which malonic acid is decomposed into malonate; and A method for producing a metal film polishing slurry composition, comprising the step of preparing a metal film polishing slurry composition in which an iron-malonate complex is formed by adjusting the pH of the third reaction solution to acidity.

14. In paragraph 13, A method for producing a slurry composition for polishing a metal film, characterized in that the iron ion salt is a trivalent iron ion salt or a divalent iron ion salt.

15. In paragraph 14, The above trivalent iron ion salts are iron sucrose, iron(III) oxide, iron(III) acetate, iron(III) sulfate, lithium iron(III) oxide, iron(III) phosphate, iron(III) pyrophosphate, iron(III) ionophore IV, ammonium iron(III) hexacyanoferrate(II), iron(III) ferrocyanide, iron(III) i-propoxide, iron(III) oxo acetate perchlorate, Ammonium iron(III) citrate, iron(III) dicarbonate, iron(III) acetylacetonate, iron(III) bromide, iron(III) chloride, iron(II) arsenide, iron(III) oxalate, ammonium iron(III) oxalate, iron(III) fluoride, iron(III) iodide, iron(III) nitrate, iron(III) phthalocyanine chloride,A method for producing a slurry composition for polishing a metal film, characterized in that it comprises at least one selected from the group consisting of iron(III) perchlorate, iron(III) sulfate, ammonium iron(III) sulfate, and iron(III) tartrate.

16. In paragraph 14, The above divalent iron ion salts are iron(II) oxide, iron(II) acetate, iron(II) sulfate, lithium iron(II) oxide, iron(II) phosphate, iron(II) pyrophosphate, iron(II) ionophore IV, ammonium iron(II) hexacyanoferrate(II), iron(II) ferrocyanide, iron(II) i-propoxide, iron(II) oxo acetate perchlorate, ammonium iron(II) citrate. iron(II) citrate), iron(II) dicarbonate, iron(II) acetylacetonate, iron(II) bromide, iron(II) chloride, iron(II) arsenide, iron(II) oxalate, ammonium iron(II) oxalate, iron(II) fluoride, iron(II) iodide, iron(II) nitrate, iron(II) phthalocyanine chloride, iron(II) perchlorate, iron(II) sulfate sulphate),A method for producing a slurry composition for polishing a metal film, characterized in that it comprises at least one selected from the group consisting of ammonium iron(II) sulfate and iron(II) tartrate.

17. In paragraph 13, A method for producing a slurry composition for polishing a metal film, characterized in that the alkalinity is pH 10 to 11 and the acidity is pH 2 to 3.

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