Slurry composition for polishing metal films

Abstract

The present invention relates to a slurry composition for polishing metal films, comprising an abrasive, an oxidizing agent, and an oxidation catalyst. According to the present invention, by using an iron-malonate complex compound as an oxidation catalyst, it exhibits a higher energy state compared to conventional iron complex compounds, i.e., complex compounds in which iron ions are coordinately bonded with water or a hydroxide group. Therefore, it reacts with peroxides, which are oxidizing agents, to promote radical formation reactions. Consequently, a polishing composition using an iron-malonate complex compound as an oxidation catalyst can improve the polishing speed by increasing the generation of radicals.

Description

[Technical Field]

[0001] The present invention relates to a slurry composition for polishing, and more particularly to a slurry composition for polishing metal films. [Background technology]

[0002] Semiconductors, as they are called integrated circuits, rely on the stacking of tiny circuits one by one, and this is the core of their quality. Therefore, flattening the wafer surface is extremely important, and for this purpose, chemical mechanical planarization (CMP) is used. The CMP process flattens each layer on the wafer, improving the shape and positional accuracy of subsequent patterns across the entire wafer.

[0003] The aforementioned chemical mechanical planarization process requires a polishing slurry, but polishing slurries capable of polishing metal films generally require an oxidizing agent that can oxidize the surface of the metal film. Furthermore, while metal ion catalysts have been used as oxidation catalysts to enable the oxidizing agent to perform its oxidation action, there has been a problem in that the desired polishing speed cannot be obtained. As a result, there is currently a continuing demand for new polishing slurry compositions that can improve productivity with high polishing speeds. [Overview of the project] [Problems that the invention aims to solve]

[0004] Therefore, the problem that the present invention aims to solve is to provide a slurry composition for polishing metal films that has an excellent metal polishing speed.

[0005] The technical problems of the present invention are not limited to those mentioned above, and other technical problems not mentioned can be clearly understood by those skilled in the art from the following description. [Means for solving the problem]

[0006] To achieve the aforementioned technical objectives, one aspect of the present invention provides a slurry composition for polishing metal films. The slurry composition for polishing metal films comprises a solvent, an abrasive, an oxidizing agent, and an oxidation catalyst, wherein the oxidation catalyst comprises an iron-malonate complex compound.

[0007] The aforementioned iron-malonate complex compound is Fe(III)(C3H2O4) x (OH) 6-2x Or Fe(II)(C3H2O4) x (OH) 6-2x (x can be an integer from 1 to 3)

[0008] The iron-malonate complex compound may also be Fe(III)(C3H2O4)2(OH)2 or Fe(II)(C3H2O4)2(OH)2.

[0009] The aforementioned iron-malonate complex compound shows that the COO peak area is larger than the Fe-OH peak area in the O1s X-ray photoelectron spectroscopy (XPS) graph. - It is characterized by an even larger peak area.

[0010] The iron-malonate complex compound is characterized by exhibiting Fe-OC peaks, Fe-OH peaks, and Fe-O=C peaks in an X-ray absorption spectroscopy (XAS) graph.

[0011] The oxidation catalyst may be present in the metal film polishing slurry composition in an amount of 0.00025 moles to 2.5 moles per 100 g of solvent.

[0012] The abrasive may include metal oxides, metal nitrides, metal oxynitrides, and mixtures thereof.

[0013] The abrasive may be present in the metal film polishing slurry composition in an amount of 0.0001% to 10% by weight per 100g of solvent.

[0014] The oxidizing agent may be selected from the group consisting of hydrogen peroxide, periodic acid, periodate, perbromic acid, perbromate, perchloric acid, perborate, and permanganate.

[0015] The oxidizing agent may be present in the metal film polishing slurry composition in an amount of 0.003 moles to 30 moles per 100 g of solvent.

[0016] The aforementioned metal film polishing slurry composition may further contain glycine.

[0017] The aforementioned metal film polishing slurry composition may further contain a pH adjusting agent.

[0018] Another aspect of the present invention provides a method for producing the metal film polishing slurry composition. The method for producing the metal film polishing slurry composition includes the steps of: producing a first reaction solution by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent; producing a second reaction solution in which an iron-glycine complex compound is formed by adding glycine to the first reaction solution and adjusting the pH to be basic; producing a third reaction solution in which malonic acid is decomposed into malonate by adding malonic acid to the second reaction solution; and producing a metal film polishing slurry composition in which an iron-malonate complex compound is formed by adjusting the pH of the third reaction solution to be acidic.

[0019] The iron ion salt may be a trivalent iron ion salt or a divalent iron ion salt.

[0020] The aforementioned trivalent iron ion salts include iron(III) sucrose, iron(III) oxide, iron(III) acetate, iron(III) sulfate, lithium iron(III) oxide, iron(III) phosphate, iron(III) pyrophosphate, iron(III) ionophore IV, and ammonium iron(III) hexacyanopherate (II). 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(III) arsenide, iron(III) oxalate, ammonium iron(III) oxalate iron(III)oxalate, iron(III)fluoride, iron(III)iodide, iron(III)nitrate, iron(III)phthalocyanine chlorideIt may contain at least one selected from the group consisting of chloride, iron(III) perchlorate, iron(III) sulfate, ammonium iron(III) sulfate, and iron(III) tartrate.

[0021] The aforementioned divalent iron ion salts 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) ferrocyanide, iron(II) i-propoxide, and iron(II) oxoacetate perchlorate. 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) iodide, iron(II) nitrate, iron(II) phthalocyanine chloride chloride, iron(II) perchlorate, iron(II) sulfate, ammonium iron(II) sulfateIt may contain at least any one selected from the group consisting of iron(II) sulfate and iron(II) tartrate.

[0022] The basicity may have a pH of 10 to 11, and the acidity may have a pH of 2 to 3.

Advantages of the Invention

[0023] According to the present invention, by using an iron-malonate complex compound as an oxidation catalyst, when compared with a conventional iron complex compound, that is, a complex compound in which water or a hydroxyl group is coordinated to an iron ion, it shows a higher energy state. Therefore, it reacts with a peroxide as an oxidizing agent to promote a radical formation reaction. Thus, a polishing composition using an iron-malonate complex compound as an oxidation catalyst can improve the polishing rate by increasing the generation of radicals.

[0024] However, the effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly understood by those skilled in the art from the following description.

Brief Description of the Drawings

[0025] [Figure 1] Figure 1 is a diagram showing the energy state of an iron complex compound according to the present invention. [Figure 2] Figure 2 is a flowchart showing a method for manufacturing a slurry composition for polishing a metal film according to an embodiment of the present invention. [Figure 3] Figure 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. [Figure 4] Figure 4 is a spectrum showing 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. [Figure 5] Figure 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. [Figure 6] Figure 6 is a graph showing the polishing speed of polishing slurries on tungsten wafers according to one embodiment and a comparative example of the present invention. [Modes for carrying out the invention]

[0026] Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings in order to illustrate the present invention more concretely. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Where a layer is referred to as being "on top of" another layer or substrate in the drawings, it may be formed directly on the other layer or substrate, or a third layer may be interposed between them.

[0027] Slurry composition for polishing metal films One aspect of the present invention provides a slurry composition for polishing metal films. The slurry composition for polishing metal films according to one embodiment of the present invention comprises a solvent, an abrasive, an oxidizing agent, and an oxidation catalyst.

[0028] The aforementioned solvent serves to disperse the components of the metal film polishing slurry composition so that each component can be easily blended. Water, specifically ultrapure water or deionized water, may be used, but is not limited to these.

[0029] The abrasive may include metal oxides, metal nitrides, metal oxynitrides, and mixtures thereof, and more specifically, it 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, more specifically colloidal silica. Unlike ceria abrasives, such silica abrasives can suppress aggregation when used with an oxidizing agent. The abrasive may be contained in the metal film polishing slurry composition at a concentration of 0.0001% to 10% by weight, more specifically 0.2 to 5% by weight, and more specifically 1 to 3% by weight, per 100 g of solvent. The abrasive may be spherical particles having an average diameter of about 10 to 100 nm.

[0030] The oxidizing agent is a substance that oxidizes the surface of a metal film with a soft metal oxide, making it easier to remove by mechanical polishing with a polishing pad, and may be a peroxide. Such a peroxide can easily oxidize the surface of the metal film by generating reactive radicals, such as hydroxyl radicals (·OH) or hydroperoxyl radicals (·OOH). Such a peroxide may be, for example, hydrogen peroxide, periodic acid, periodate, perbromic acid, perbromate, perchloric acid, perborate, and permanganate, or compounds containing these. In one specific example, the peroxide may be hydrogen peroxide. The oxidizing agent may be contained in the metal film polishing slurry composition in an amount of 0.003 moles to 30 moles, specifically 3 moles to 20 moles, per 100 g of solvent.

[0031] The oxidation catalyst is a substance that promotes the conversion of the peroxide, which is the oxidizing agent, into radicals. These radicals have a very high metal oxidizing power. That is, the higher the effect of the oxidation catalyst for oxidant decomposition, the more the radical generation increases, thereby improving the surface oxidation effect and the polishing rate. In the present invention, it is characterized by containing an iron-malonate complex compound as such an oxidation catalyst.

[0032] FIG. 1 is a diagram showing the energy state of the iron complex compound according to the present invention.

[0033] Referring to FIG. 1, the higher the energy state of Fe ions, the more the reaction with peroxide to form radicals can be promoted. However, the iron-malonate complex compound according to the present invention shows a higher energy state when compared with a complex compound coordinated with water or a hydroxyl group. Therefore, it reacts with peroxide to promote the radical formation reaction. Thus, when the iron-malonate complex compound is used as an oxidation catalyst, the polishing rate can be improved by increasing the generation of radicals.

[0034] The oxidation catalyst may be an iron-malonate complex compound formed by the coordination bond of malonate with trivalent or divalent iron ion hydrate. Specifically, the iron-malonate complex compound is Fe(III)(C3H2O4) x (OH) 6-2x or Fe(II)(C3H2O4) x (OH) 6-2x (x is an integer from 1 to 3). Specifically, the x may be 2. That is, the iron-malonate complex compound may be Fe(III)(C3H2O4)2(OH)2 or Fe(II)(C3H2O4)2(OH)2.

[0035] The iron-malonate complex compound is characterized in that the COO - peak area is larger than the Fe-O-H peak area in the O1s X-ray photoelectron spectroscopy (XPS) graph.

[0036] The iron-malonate complex compound is characterized by exhibiting Fe-OC peaks, Fe-OH peaks, and Fe-O=C peaks in an X-ray absorption spectroscopy (XAS) graph.

[0037] Such oxidation catalysts may be present in a slurry composition for metal film polishing in an amount of 0.00025 moles to 2.5 moles per 100 g of solvent.

[0038] The aforementioned metal film polishing slurry composition may further contain glycine.

[0039] The aforementioned metal film polishing slurry composition may further contain a pH adjusting agent. The pH adjusting agent 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 as an example, the pH may be adjusted to 2.0 to 2.5.

[0040] The aforementioned metal film polishing slurry composition may contain a diluent, which may be water, preferably ultrapure water or deionized water.

[0041] The aforementioned metal film polishing slurry composition may further contain one or more additives selected from the group consisting of dispersants, surfactants, polishing inhibitors, planarizers, slurry stabilizers, and chelating agents.

[0042] The aforementioned metal film polishing slurry composition may have a polishing rate of 500 Å / min or more against a tungsten film. Specifically, the metal film polishing slurry composition according to one embodiment of the present invention, by including iron-malonate as an oxidation catalyst in addition to the abrasive and oxidizing agent, exhibits a polishing rate of 500 Å / min or more, specifically 588 Å / min, against a tungsten film. This represents a significantly improved polishing rate compared to the case without additives (50-60 Å / min) and the case where iron ions are included as an oxidation catalyst but no iron-malonate complex compound is formed (approximately 300 Å / min). Furthermore, the aforementioned metal film polishing slurry composition can improve the polishing rate not only of the tungsten film but also of other metal films such as Cu and SiC.

[0043] Method for producing a slurry composition for polishing metal films Another aspect of the present invention provides a method for producing a slurry composition for polishing metal films.

[0044] Figure 2 is a flowchart showing a method for producing a metal film polishing slurry composition according to one embodiment of the present invention.

[0045] Referring to Figure 2, the method for producing the metal film polishing slurry composition is as follows: The first reaction solution is prepared by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent. The process involves adding glycine to the first reaction solution and adjusting the pH to be basic to produce a second reaction solution in which an iron-glycine complex compound is formed, The steps include adding malonic acid to the second reaction solution to produce a third reaction solution in which the malonic acid is decomposed into malonate, The process includes the step of adjusting the pH of the third reaction solution to an acidic state to produce a metal film polishing slurry composition in which an iron-malonate complex compound is formed.

[0046] The method for producing the metal film polishing slurry composition according to the present invention will be described in detail step by step below.

[0047] First, the first reaction solution is prepared by mixing the abrasive, oxidizing agent, and iron ion salt in a solvent.

[0048] The solvent, abrasive, and oxidizing agent are the same as those described above in the [metal film polishing slurry composition], so a detailed explanation will be omitted to avoid duplication.

[0049] The aforementioned iron ion salt serves as an iron ion source for producing iron-malonate complex compounds used as oxidation catalysts, and trivalent or divalent iron ion salts can be used.

[0050] In this case, 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, and ammonium iron(III) hexacyanopherate (II). 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(III) arsenide, iron(III) oxalate, ammonium iron(III) oxalate iron(III)oxalate, iron(III)fluoride, iron(III)iodide, iron(III)nitrate, iron(III)phthalocyanine chlorideThe divalent iron ion salt 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, and ammonium iron(II) hexacyanopherate(II) (ammonium 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 (ironIII)), ammonium iron(II) oxalateIt may contain at least one selected from the group consisting of iron(II)oxalate, iron(II)fluoride, iron(II)iodide, iron(II)nitrate, iron(II)phthalocyanine chloride, iron(II)perchlorate, iron(II)sulfate, ammonium iron(II)sulfate, and iron(II)tartrate.

[0051] The glycine acts as a precursor agent to facilitate the complex compound formation reaction with malonate, preventing the subsequent hydroxide formation of iron ions by forming a complex compound with iron ion salts. In this case, since the glycine forms a complex compound with iron ions under basic conditions, it is preferable to adjust the pH of the first reaction solution to basic in subsequent steps. The abrasive and oxidizing agents are not affected by pH.

[0052] Next, adjust the pH of the first reaction solution to be basic.

[0053] As mentioned above, in order to react glycine with an iron ion salt to form a complex compound, the pH of the reaction solution must be basic. Therefore, the pH of the first reaction solution containing glycine and an iron ion salt is adjusted to basic, for example, pH 10-11. This pH adjustment can be done by using a basic pH additive, and specifically, TMAH (TetraMethylAmmonium Hydroxide), KOH, NaOH, or NH4OH can be used as the basic pH additive, but are not limited to these.

[0054] By adjusting the pH of the first reaction solution to a basic state, a second reaction solution is produced in which glycine and iron ion salts react to form an iron-glycine complex compound. As a result, the second reaction solution contains an abrasive, an oxidizing agent, and the iron-glycine complex compound.

[0055] Next, malonic acid is added to the second reaction solution to form a third reaction solution.

[0056] The aforementioned malonic acid plays a role in providing the malonate in the iron-malonate complex compound.

[0057] The malonic acid is degraded in the basic region, COO - It forms malonates containing ions. Specifically, iron-malonate complex compounds are formed when malonic acid is decomposed and converted to malonate, which then forms a coordinate bond with iron ions. However, the pKa required for malonic acid to become malonate is 5.70, and below this pH, it exists in the COOH form, making it difficult to form complex compounds.

[0058] Furthermore, at basic pH, malonic acid decomposes and malonate is formed, but iron ions are hydroxylated and precipitated, making it difficult to form iron-malonate complex compounds at basic pH alone. Therefore, to prevent the hydroxylation of iron ions, a method can be used in which a complex compound is preferentially formed with glycine in the basic region first, and then coordinated with malonate.

[0059] As a result, the third reaction solution contains an abrasive, an oxidizing agent, an iron-glycine complex compound, and a malonate.

[0060] Next, the pH of the basic third reaction solution is adjusted to acidic.

[0061] The acidic range can be adjusted to pH 2-3. This pH adjustment can be achieved by using an acidic pH additive; specifically, HCl, HNO3, H2SO4, or H3PO4 can be used as the acidic pH additive, but are not limited to these. The COO of malonate in the third reaction solution... - The ions move to the acidic region, where they do not attach protons, and react with iron-glycine, substituting the glycine to form an iron-malonate complex. This can be confirmed by Raman analysis and XPS analysis, as described later.

[0062] The resulting slurry composition contains an abrasive, an oxidizing agent, glycine, and an iron-malonate complex compound.

[0063] According to the present invention, by using an iron-malonate complex compound as an oxidation catalyst, it exhibits a higher energy state compared to conventional iron complex compounds, i.e., complex compounds in which iron ions are coordinately bonded with water or a hydroxide group. Therefore, it reacts with peroxides, which are oxidizing agents, to promote radical formation reactions. Consequently, polishing compositions using an iron-malonate complex compound as an oxidation catalyst can improve the polishing speed by increasing radical generation. [Examples]

[0064] The following are examples of preferred experiments to aid in understanding the present invention. However, these examples are merely for the purpose of aiding in understanding the present invention, and the present invention is not limited to these examples.

[0065] Examples and comparative examples of slurry compositions for polishing metal films. [Manufacturing example] To a solution containing an abrasive agent with a particle size of 30 nm and containing 2.5% by weight of silica as an abrasive agent in 100 g of ultrapure water, 3 moles of hydrogen peroxide as an oxidizing agent and 0.22 moles of nitrate-formed Fe(III) ion salt as a catalyst were added to prepare an iron ion solution. Then, 6.7 moles of glycine were added, and the pH was titrated to 10 to form an iron-glycine complex compound. Finally, 4.8 moles of malonic acid were added, and the pH was titrated to 2.3 to displace malonate at the glycine position, forming an iron-malonate complex compound. This prepared a slurry composition for polishing metal films.

[0066] [Comparative Example 1] Unlike the composition preparation described in the above-mentioned production example, the slurry composition was prepared by titrating the abrasive-containing solution to pH 2.3 without adding hydrogen peroxide, iron ion salt, malonic acid, and glycine.

[0067] [Comparative Example 2] In the preparation of the composition of Comparative Example 1, the pH was first stabilized by titrating to 10 before adjusting the pH to 2.3, and then further titrated to pH 2.3 to produce the slurry composition.

[0068] [Comparative Example 3] In the preparation of the composition of Comparative Example 1, before adjusting the pH to 2.3, 3 moles of hydrogen peroxide and 0.22 moles of iron ion salt were further added to 100 g of solvent to prepare the slurry composition.

[0069] [Comparative Example 4] In the preparation of the composition of Comparative Example 3, the pH was first stabilized by titrating to 10 before adjusting the pH to 2.3, and then further titrated to pH 2.3 to produce the slurry composition.

[0070] [Comparative Example 5] In the preparation of the composition of Comparative Example 3, 4.8 moles of malonic acid were further added before adjusting the pH to 2.3 to produce a slurry composition.

[0071] [Comparative Example 6] In the preparation of the composition of Comparative Example 3, the pH was stabilized by titrating to 10 before adjusting the pH to 2.3, then 4.8 moles of malonic acid were added, and the mixture was further titrated to pH 2.3 to produce a slurry composition.

[0072] [Comparative Example 7] In the preparation of the composition of Comparative Example 3, 6.7 moles of glycine were added before adjusting the pH to 2.3 to produce a slurry composition.

[0073] [Comparative Example 8] In the preparation of the composition of Comparative Example 3, 6.7 moles of glycine were added before adjusting the pH to 2.3, and the pH was titrated to 10 to stabilize it. Then, the mixture was further titrated to pH 2.3 to produce the slurry composition.

[0074] [Comparative Example 9] In the production of the composition described above, the adjustment of pH to 10 was omitted, and the slurry composition was produced by titrating to pH 2.3.

[0075] The composition and pH of the metal film polishing slurry compositions produced in the above-mentioned production examples and comparative examples are summarized in Table 1 below.

[0076] [Table 1]

[0077] [Experimental Example 1: Analysis of the presence or absence of iron-malonate formation in a slurry composition for polishing metal films] In the metal film polishing slurry composition according to the present invention, in order to investigate whether or not iron-malonate formation occurs due to the addition of malonic acid and glycine and pH adjustment during the manufacturing process of the composition, Raman analysis was performed on various slurry compositions to determine OH bend, COO - The spectra for the COOH peak were also measured and are shown in Figure 3.

[0078] Figure 3 shows the Raman analysis spectra of a metal film polishing slurry composition according to one comparative example and one example of the present invention.

[0079] In this context, MGF10-2.3 refers to a polishing slurry composition containing malonic acid (M), glycine (G), and iron ions (Fe), which is titrated to pH 10 and then adjusted to pH 2.3. MGF10 refers to a mixture where the pH is adjusted to 10 only, and MGF2.3 refers to a mixture where the pH is adjusted to 2.3 only.

[0080] Furthermore, when only malonic acid and iron ions were added to the polishing composition, this was indicated by MF.

[0081] As shown in Figure 3, in the acidic region, OH bends due to malonic acid appear, but in the case of MGF10-2.3, OH bends did not appear compared to MGF2.3. This is because, as shown in the right panel of Figure 3, in the case of MGF10-2.3, COO - This is because, by moving to the acidic region, protons do not attach, and a chelate structure is formed.

[0082] Furthermore, in the COOH peak region, the COOH peak that appears in acids appears in MF2.3 and MGF2.3, but in the case of MGF10-2.3, the COOH peak did not appear. From this, it can be concluded that the carboxylate (COOH) of malonate produced when malonic acid is decomposed by a base is formed. - , 1640cm -1 It was found that the structure is partially maintained even in the acidic region (pH 2.3), indicating that, in an acidic atmosphere, the iron-malonate complex compound structure is formed more favorably due to the synergistic effect with glycine compared to the addition of malonic acid alone without glycine.

[0083] Furthermore, to investigate the presence or absence of iron-malonate formation in the same MGF composition with or without pH adjustment, XPS analysis and XAS analysis were performed, and the results are shown in Figures 4 and 5, respectively.

[0084] Figure 4 shows the spectra of O1s and C1s from XPS analysis of a metal film polishing slurry composition according to one comparative example and an example of the present invention.

[0085] As shown in Figure 4, when comparing the case in which malonic acid (M), glycine (G), and iron ions (Fe) are added to the metal film polishing slurry composition according to the present invention, and the pH is titrated to a basic state and then controlled to an acidic state (MGF10-2.3), with the case in which the pH is immediately titrated to 2.3 (MGF2.3), the O1s peak is higher in the case in which the pH is titrated to a basic state and then controlled to an acidic state according to the present invention (MGF10-2.3), and COO - We confirmed that even more peaks were detected.

[0086] Furthermore, in the C1s peak, the area of ​​the CO-Fe peak increased when the pH was titrated to a basic state and then controlled to an acidic state according to the present invention (MGF10-2.3). This indicates that when the pH is titrated to a basic state and then controlled to an acidic state according to the present invention (MGF10-2.3), an Fe-malonate complex compound is formed.

[0087] Figure 5 shows the spectra of XAS analysis of a metal film polishing slurry composition according to one comparative example and an example of the present invention.

[0088] According to the present invention, by adding malonic acid (M), glycine (G), and iron ions (Fe) to a slurry composition for polishing metal films, and then comparing the results using XAS (X-analytic assay) with the case where the pH is titrated to basic and then controlled to acidic (MGF10-2.3) and the case where the pH is immediately titrated to 2.3 (MGF2.3), the complex ion bond distance of the formed Fe complex compound can be confirmed.

[0089] As shown in Figure 5, when the pH was immediately titrated to 2.3 (MGF2.3), only the Fe-OH peak appeared. However, when the pH was controlled to be basic and acidic according to the present invention, the Fe-OC peak and Fe-O=C peak appeared, indicating that a malonate complex compound was formed.

[0090] Furthermore, when comparing the areas of the peaks, the ratio of Fe-OH to Fe-OC appears to be approximately 1:1, which suggests that the ratio of Fe-OC:Fe-O=C:Fe-OH is 1:1:1. This means that at the Fe site, which has a total of 6 ligand adsorption sites, there are 2 Fe-OC coordinate bonds, 2 Fe-O=C coordinate bonds, and 2 Fe-OH coordinate bonds. This suggests that 2 malonate complex ions are adsorbed on Fe, and 2 OH groups are adsorbed on Fe.

[0091] [Experimental Example 2: Measurement of polishing speed in chemical mechanical polishing (CMP) using a slurry composition for polishing metal films] Tungsten wafers were chemically mechanically polished (CMP) using the various polishing slurry compositions produced in the above-mentioned manufacturing example and comparative example as polishing slurry. The CMP apparatus used was a G&P Poli 300, the CMP polishing pad was a Dow Chemical IC1010, the rotation speed of the polishing pad was 83 rpm, the rotation speed of the table on which the wafer was mounted 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.

[0092] The thickness of each tungsten wafer before and after polishing was measured, and the polishing rate was calculated. The results are shown in Table 1 and Figure 6.

[0093] Figure 6 is a graph showing the polishing speed of polishing slurries on tungsten wafers according to one embodiment and a comparative example of the present invention.

[0094] As shown in Table 1 and Figure 6, when the polishing slurry contained only the abrasive without any other additives, the polishing rate was low at 50-60 Å / min. However, when iron ions, a mixture of iron ions and malonic acid, or a mixture of iron ions and glycine were used as the oxidizing agent and oxidation catalyst, no iron-malonate complex compound was formed, and the polishing rate remained in the 300 Å / min range regardless of pH, showing a slight increase in polishing rate. However, when the oxidizing agent contained iron ions, malonic acid, and glycine as oxidation catalysts, and the pH was titrated to basic and then controlled to acidic (MGF10 → 2.3), iron-malonate was formed, and the polishing rate reached 588 Å / min. This was a significant increase of more than 10 times compared to the case without additives, and about twice as high compared to the case with malonic acid and glycine alone.

[0095] Therefore, the metal film polishing slurry composition according to the present invention, by using an iron-malonate complex compound as an oxidation catalyst in addition to the abrasive and oxidizing agent, exhibits a higher energy state compared to conventional iron complex compounds, i.e., complex compounds in which iron ions are coordinately bonded with water or a hydroxide group. As a result, it reacts with the peroxide, which is the oxidizing agent, to promote the radical formation reaction. Consequently, polishing compositions using an iron-malonate complex compound as an oxidation catalyst can improve the polishing speed by increasing the generation of radicals.

[0096] Although the present invention has been described in detail above based on preferred embodiments, the present invention is not limited to the above embodiments, and various modifications and changes are possible by those with ordinary skill in the art within the technical spirit and scope of the present invention.

Claims

1. Solvent and, Abrasives and Oxidizing agent, It contains an oxidation catalyst, The oxidation catalyst is a slurry composition for polishing metal films, comprising an iron-malonate complex compound.

2. The iron-malonate complex compound is Fe(III)(C ３ H ２ O ４ )( ｘ (OH) ６－２ｘ Or Fe(II)(C ３ H ２ O ４ )( ｘ (OH) ６－２ｘ (x is an integer from 1 to 3), and the slurry composition for polishing a metal film according to claim 1 is characterized in that

3. The aforementioned iron-malonate complex compound is Fe(III)(C) ３ H ２ O ４ ) ２ (OH) ２ or Fe(II)(C ３ H ２ O ４ ) ２ (OH) ２ The slurry composition for polishing metal films according to claim 2, characterized in that it is the same as the one described in claim 2.

4. The aforementioned iron-malonate complex compound shows that the Fe-O-H peak area is larger than the COO peak area in the O1s X-ray photoelectron spectroscopy (XPS) graph. － The slurry composition for polishing metal films according to claim 1, characterized by having an even larger peak area.

5. The metal film polishing slurry composition according to claim 1, characterized in that the iron-malonate complex compound exhibits an Fe-O-C peak, an Fe-OH peak, and an Fe-O=C peak in an X-ray absorption spectroscopy (XAS) graph.

6. The metal film polishing slurry composition according to claim 1, characterized in that the oxidation catalyst is contained in an amount of 0.00025 moles (mol) to 2.5 moles (mol) per 100 g of solvent in the metal film polishing slurry composition.

7. The slurry composition for polishing metal films according to claim 1, characterized in that the abrasive comprises a metal oxide, a metal nitride, a metal oxynitride, and mixtures thereof.

8. The metal film polishing slurry composition according to claim 1, characterized in that the abrasive is contained in an amount of 0.0001% to 10% by weight per 100 g of solvent in the metal film polishing slurry composition.

9. The slurry composition for polishing metal films according to claim 1, characterized in that the oxidizing agent is selected from the group consisting of hydrogen peroxide, periodic acid, periodate, perbromic acid, perbromate, perchloric acid, perborate, and permanganate.

10. The metal film polishing slurry composition according to claim 1, characterized in that the oxidizing agent is contained in an amount of 0.003 moles (mol) to 30 moles (mol) per 100 g of solvent in the metal film polishing slurry composition.

11. The metal film polishing slurry composition according to claim 1, further comprising glycine.

12. The metal film polishing slurry composition according to claim 1, further comprising a pH adjusting agent.

13. The first reaction solution is prepared by mixing an abrasive, an oxidizing agent, and an iron ion salt in a solvent. The process involves adding glycine to the first reaction solution and adjusting the pH to be basic to produce a second reaction solution in which an iron-glycine complex compound is formed, The process involves adding malonic acid to the second reaction solution to produce a third reaction solution in which the malonic acid is broken down into malonate, A method for producing a metal film polishing slurry composition, comprising the step of adjusting the pH of the third reaction solution to acidity to produce a metal film polishing slurry composition in which an iron-malonate complex compound is formed.

14. The method for producing a metal film polishing slurry composition according to claim 13, characterized in that the iron ion salt is a trivalent iron ion salt or a divalent iron ion salt.

15. The aforementioned 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, and ammonium iron(III) hexacyanopherate (II). iron(III)hexacyanoferrate(II), iron(III) ferrocyanide, iron(III) i-propoxide, iron(III) oxoacetate perchlorate, ammonium iron(III) citrate 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)oxalate, iron(III) fluoride, iron(III) iodide, iron(III) nitrate, iron(III) phthalocyanine chlorideA method for producing a metal film polishing slurry composition according to claim 14, characterized by comprising at least one selected from the group consisting of chloride, iron(III) perchlorate, iron(III) sulfate, ammonium iron(III) sulfate, and iron(III) tartrate.

16. The aforementioned divalent iron ion salts include iron(II) oxide, iron(II) acetate, iron(II) sulfate, lithium iron(II) oxide, iron(II) phosphate, iron(II) pyrophosphate, iron(II) ionophore IV, and ammonium iron(II) hexacyanopherate(II). iron(II) hexacyanoferrate(II), iron(II) ferrocyanide, iron(II) i-propoxide, iron(II) oxoacetate 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) oxalate, iron(II) fluoride, iron(II) iodide, iron(II) nitrate, iron(II) phthalocyanine chloride, iron(II) perchlorate, iron(II) sulfate, ammonium iron(II) sulfateA method for producing a metal film polishing slurry composition according to claim 14, characterized by comprising at least one selected from the group consisting of iron(II) sulfate and iron(II) tarrate.

17. The method for producing a metal film polishing slurry composition according to claim 13, characterized in that the basicity has a pH of 10 to 11, and the acidity has a pH of 2 to 3.

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