KR20060118396A - Slurries and methods for chemical-mechanical planarization of copper - Google Patents

Abstract

The claimed invention involves a novel aqueous slurry for chemical-mechanical planarization that is effective for polishing copper at high polish rates. The aqueous slurry according to the present invention comprises particles of MoO2 or MoO3 and an oxidizing agent. A method for polishing copper by chemical-mechanical planarization includes contacting copper with a polishing pad and an aqueous slurry comprising particles of MoO2 or MoO3 and an oxidizing agent.

Description

SLURRIES AND METHODS FOR CHEMICAL-MECHANICAL PLANARIZATION OF COPPER}

 The present invention relates to chemical-mechanical planarization methods and in particular molybdenum oxide slurries and methods for chemical-mechanical planarization of copper.

Chemical-mechanical planarization (CMP) is a term associated with the method used in semiconductor processing. As the term suggests, CMP processes are commonly used in semiconductors to polish (eg, planarize) the surface of a semiconductor wafer. The CMP process is a relatively new method in that conventional methods are sufficient by relatively low circuit density. However, increasing the circuit density (eg, moving from 0.25 micron wafers to 0.18 micron features) has led to the development of new methods for planarizing wafers. Similarly, a faster move from aluminum interconnect technology to copper interconnect technology has facilitated the use of CMP to polish (eg, planarize) semiconductor wafers.

In summary, the chemical-mechanical planarization (CMP) process involves rubbing a semiconductor wafer using a pad in the presence of a chemically reactive slurry containing abrasive particles. The planarization action of the chemical-mechanical planarization (CMP) is a chemical and mechanical action. The chemical aids in material removal by adjusting the surface film while polishing between the surface particles and the pad, and the controlled film promotes mechanical removal. This synergistic interaction between chemical and mechanical components in the process is key to an effective CMP process.

While CMP processes are increasingly used in semiconductor manufacturing methods, the CMP processes are not well understood and the exact mechanism of action for the process operations has not been established. For example, while specific parameters for the CMP process have been developed and are satisfactory for wafers using aluminum interconnect technology, these same process parameters are particularly satisfactory for use in wafers using copper interconnect technology. Not proven. One important requirement for successful CMP slurries for copper is high polishing rates. High polishing rates shorten copper overburden planarization times.

Summary of the Invention

The following summary provides a brief overview of the claimed products and processes and does not limit the scope of the invention. The invention is not limited to any numerical parameters, process equipment, chemical reagents, operating conditions and other variables unless otherwise specified.

The present invention involves a new aqueous planarization slurry for chemical-mechanical planarization that is effective for copper planarization at high polishing rates. The aqueous slurry according to the invention comprises particles of MoO ₃ dissolved in an oxidizing agent.

Specific examples of the water-based slurry for example may contain the MoO ₃ dissolved in an amount of from about 0.1% to about 10% by weight of MoO _3, wherein the oxidizing agent is hydrogen peroxide (H ₂ O _2), ferric nitrate (Fe (NO ₃ ) ₃ ), potassium iodide (KIO ₃ ), nitric acid (HNO ₃ ), potassium permanganate (KMnO ₄ ), potassium persulfate (K ₂ S ₂ O ₈ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), potassium periodate (KIO ₄ ), and hydroxylamine (NH ₂ OH), or any mixture thereof. Composites can also be used in the molybdenum trioxide (MoO ₃ ) aqueous slurry. The combination agent is glycine (C ₂ H ₅ NO ₂ ), alanine (C ₃ H ₇ NO ₂ ), amino butyric acid (C ₄ H ₉ NO ₂ ), ethylene diamine (C ₂ H ₈ N ₂ ), ethylene diamine tetraacetic acid (EDTA ), Ammonia (NH ₃ ), citric acid (C ₆ H ₈ O ₇ ), phthalic acid (C ₆ H ₄ (COOH) ₂ ), oxalic acid (C ₂ H ₂ O ₄ ), acetic acid (C ₂ H ₂ O ₂ ), And any one or mixture of mono, di and tri carboxylic acid series and amino benzoic acid series such as succinic acid (C ₄ H ₆ O ₄ ).

Embodiments of slurries containing molybdenum trioxide (MoO ₃ ) may also be provided with nonionic surfactants, anionic surfactants or cationic surfactants. The anionic surfactants of the aqueous slurry may comprise polyacrylic acid (PAA), carboxylic acid or salts thereof, sulfate esters or salts thereof, sulfonic acid or salts thereof, phosphoric acid or salts thereof, and sulfosuccinic acid or salts thereof or mixtures thereof. It may include. The cationic surfactant of the aqueous slurry may comprise any one or mixture of primary amines or salts thereof, secondary amines or salts thereof, tertiary amines or salts thereof and quaternary amines or salts thereof. The nonionic surfactant may comprise any one or mixture of many polyethylene glycols.

Another embodiment of the aqueous slurry may include any one or mixture of heterocyclic organic compounds, including benzotriazole (BTA), benzimidazole, poly triazole, phenyl triazole, thion and derivatives thereof. Copper corrosion inhibitors may be provided. Other embodiments of the slurry may contain any combination of these surfactants and corrosion inhibitors.

The aqueous slurry may optionally include an acid or base to adjust pH within an effective range of about 1 to about 14. Another embodiment of the slurry according to the invention may also be provided with supplementary ceramic oxide / metal particles. Such supplemental ceramic oxide / metal particles used in the aqueous slurry may include any one or mixture of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide and germania.

The invention also includes a novel method of copper planarization by chemical-mechanical planarization. The method involves copper planarization with an oxidant and an aqueous slurry comprising a polishing pad and dissolved MoO ₃ particles.

Specific examples of the copper planarization method using the slurry may contain a MoO ₃ dissolved in an amount of from about 0.1% to about 10% by weight of MoO _3, wherein the oxidizing agent is hydrogen peroxide (H ₂ O _2), ferric nitrate (Fe (NO ₃ ) ₃ ), potassium iodide (KIO ₃ ), nitric acid (HNO ₃ ), potassium permanganate (KMnO ₄ ), potassium persulfate (K ₂ S ₂ O ₈ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), potassium periodate (KIO ₄ ), and hydroxylamine (NH ₂ OH) or a mixture thereof. Composites can also be used in the molybdenum trioxide (MoO ₃ ) aqueous slurry. The combination agent is glycine (C ₂ H ₅ NO ₂ ), alanine (C ₃ H ₇ NO ₂ ), amino butyric acid (C ₄ H ₉ NO ₂ ), ethylene diamine (C ₂ H ₈ N ₂ ), ethylene diamine tetraacetic acid (EDTA ), Ammonia (NH ₃ ), citric acid (C ₆ H ₈ O ₇ ), phthalic acid (C ₆ H ₄ (COOH) ₂ ), oxalic acid (C ₂ H ₂ O ₄ ), acetic acid (C ₂ H ₂ O ₂ ), And any one or mixture of mono, di and tri carboxylic acid series and amino benzoic acid series such as succinic acid (C ₄ H ₆ O ₄ ).

Embodiments of the copper planarization method using a slurry containing molybdenum trioxide (MoO ₃ ) may also be provided with a nonionic surfactant, anionic surfactant or cationic surfactant. The anionic surfactants of the aqueous slurry may comprise polyacrylic acid (PAA), carboxylic acid or salts thereof, sulfate esters or salts thereof, sulfonic acid or salts thereof, phosphoric acid or salts thereof, and sulfosuccinic acid or salts thereof or mixtures thereof. It may include. The cationic surfactant of the aqueous slurry may comprise any one or mixture of primary amines or salts thereof, secondary amines or salts thereof, tertiary amines or salts thereof and quaternary amines or salts thereof. The nonionic surfactant may comprise any one or mixture of many polyethylene glycols.

Another embodiment of the aqueous slurry may include any one or mixture of heterocyclic organic compounds, including benzotriazole (BTA), benzimidazole, poly triazole, phenyl triazole, thion and derivatives thereof. Copper corrosion inhibitors may be provided. Other embodiments of the slurry may contain any combination of these surfactants and corrosion inhibitors.

The aqueous slurry may optionally include an acid or base to adjust pH within an effective range of about 1 to about 14. Another embodiment of the slurry according to the invention may also be provided with supplementary ceramic oxide / metal particles. Such supplemental ceramic oxide / metal particles used in the aqueous slurry may include any one or mixture of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide and germania.

FIG. 1 shows the dislocation planarization curves of copper and tantalum coupon of a slurry containing MoO ₃ .

Detailed Description of the Preferred Embodiments

Embodiments of the aqueous slurry according to the present invention may include molybdenum oxide (MoO ₂ ) abrasive materials and oxidants. The MoO ₂ abrasive material may be present in an amount of about 0.5 to about 10 weight percent and more preferably about 3 weight percent, such as about 1 to 3 weight percent. The molybdenum oxide abrasive material is a fine particle of MoO ₂ having an average particle size of about 25 nm to about 1 micron and more preferably about 50 to about 200 nm, such as about 25 nm to about 560 nm, as measured by Horiba laser dispersion analyzer. It may include particles.

Particles of MoO ₂ can be prepared from a number of molybdenum-containing precursor materials such as ammonium molybdate and related compounds, as well as molybdenum oxide prepared from various methods known in the art, and the molybdenum precursors and products are of the size specified herein. It can be made into particles in the range. Alternatively, the particles of MoO ₂ may be reduced to a size in the range specified herein by various milling methods known in the art, such as friction milling assisted by the use of appropriate reagents.

Embodiments of the slurry according to the invention may use particles of MoO ₂ made from precursor materials comprising nano-particles of MoO ₃ . Nano-particles of MoO ₃ are available from Climax Molybdenum Company, Madison, Iowa. Alternatively, the nano-particles of MoO ₃ may be prepared according to the method disclosed in US Pat. No. 6,468,497 B1, entitled “Method for Making Nano-Particles of Molybdenum Oxide”, which is incorporated herein by reference.

Nano of MoO ₃ - of the MoO _2, which particles comprise a, abrasive materials, whether or not made in accordance with the method commercially obtainable by or disclosed in U.S. Patent No. 6,468,497 B1 particles are substantially MoO all the MoO _{3 2} It can be produced by heating the nano-particles of MoO _{3 for} a time sufficient to convert to. More specifically, the nano-particles of MoO ₃ may be heated in a reducing environment (yellow cotton, hydrogen) at a temperature of about 400 ℃ to about 700 ℃ (preferably 550 ℃). The time required to reduce MoO ₃ to a sufficient amount of MoO ₂ may be about 30 to 180 minutes. Other types of furnaces may be used, but heating may be carried out in a rotary furnace. If desired, the resulting MoO ₂ product may then be milled to produce a MoO ₂ abrasive material having an average particle diameter in the range specified herein. A particle sorting step can optionally be used to ensure that the resulting MoO ₂ abrasive material is free of particles that can cause damage during polishing.

The oxidant may include any one or mixture of ferric nitrate (Fe (NO ₃ ) ₃ ), nitric acid (HNO ₃ ), potassium iodide (KI) and potassium iodide (KIO ₃ ). Ferric nitrate oxidizing agent, such as about 0.1 to about 0.2 M (Fe (NO ₃ ) ₃ , about 0.05 to about 0.2 M (Fe (NO ₃ ) ₃ and more preferably about 0.2 M (Fe (NO ₃ ) ₃ ) may be present in a concentration of nitric acid oxidizing agent may be present in an amount from about 1 to about 2, such as weight% HNO _3, about 0.5 to about 2 wt.% HNO _3, and more preferably from about 2 wt.% HNO _3. potassium iodide The oxidizing agent may be present in an amount of about 0.5 to about 5 weight percent KI and more preferably about 3 weight percent KI, such as about 1 to about 5 weight percent KI. as KIO _3, it is from about 1 to about 5 wt% KIO ₃ and more preferably may be present in an amount of about 3 wt% KIO _3.

Additional oxidizing agents may include any one or mixture of hydroxylamine hydrochloride ((NH ₂ OH) Cl) and potassium permanganate (KMnO ₄ ). The hydroxylamine hydrochloride oxidant is about 1 to about 5 weight percent ((NH ₂ OH) Cl) and more preferably about 3 weight percent, such as about 2 to about 4 weight percent ((NH ₂ OH) Cl). May be present in an amount of ((NH ₂ OH) Cl). Potassium permanganate oxidant may be present in an amount of about 1 to about 5 weight percent KMnO ₄ and more preferably about 3 weight percent KMnO ₄ , such as about 2 to about 4 weight percent KMnO ₄ . However, the polishing rate using a slurry containing hydroxylamine hydrochloride and potassium permanganate is generally lower than that using other oxidants disclosed herein.

Embodiments of the slurry according to the invention may also be provided with anionic surfactants or cationic surfactants. The anionic surfactants used in the aqueous slurry may be any one of polyacrylic acid (PAA), carboxylic acid or salt thereof, sulfate ester or salt thereof, sulfonic acid or salt thereof, phosphoric acid or salt thereof and sulfosuccinic acid or salt thereof or Mixtures may be included. The cationic surfactant of the aqueous slurry may comprise any one or mixture of primary amines or salts thereof, secondary amines or salts thereof, tertiary amines or salts thereof and quaternary amines or salts thereof. Optionally, the aqueous slurry may be provided with a copper corrosion inhibitor, which may comprise any one or mixture of heterocyclic organic compounds, including benzotriazole (BTA), triazole, benzimidazole. In addition, the slurry may contain any combination of these surfactants and corrosion inhibitors.

Preferred anionic surfactants are polyacrylic acids (PAA). Preferred cationic surfactants are cetyl pyridinium chloride (CPC). Preferred copper corrosion inhibitor is benzotriazole (BTA). The addition of PAA improved slurry dispersibility and surface quality. It is believed that the addition of PAA regulates the surface charge of molybdenum oxide to favor the interaction between the molybdenum oxide particles and copper, leading to an increase in the polishing rate. The polyacrylic acid (PAA) surfactant may be present in an amount of about 0.1 to about 4 weight percent PAA and more preferably about 1 weight percent PAA, such as about 0.5 to about 1 weight percent PAA. The cationic surfactant cetyl pyridinium chloride (CPC) may be present in an amount of about 0.01 to about 1 weight percent CPC and more preferably about 0.1 weight percent CPC, such as about 0.05 to about 0.5 weight percent CPC. The benzotriazole (BTA) copper corrosion inhibitor may be present at a concentration of about 0.5 to about 10 mM BTA and more preferably about 1 mM BTA, such as about 1 to about 5 mM BTA.

Embodiments of the slurry according to the invention also provide molybdenum sulfide (MoS ₂ ) as lubricant. The addition of molybdenum sulfide particles is KIO ₃ And to increase the polishing rate of copper on the slurry containing PAA. Molybdenum sulfide particles can have an average diameter of about 0.01 to about 1 micron. Molybdenum sulfide particles may be present in an amount of about 0.1 to about 10 weight percent MoS ₂ and more preferably about 1 weight percent MoS ₂ , such as about 0.5 to about 5 weight percent MoS ₂ . Molybdenum sulfide particles having this size are available from Climax Molybdenum Company, Madison, Iowa.

The pH of the slurry according to the invention may be a pH in the range of about 1 to about 14, such as a pH in the range of about 3 to about 7 and more preferably has a pH of 4. The pH of the slurry according to the invention can be adjusted by the addition of a suitable acid (eg hydrochloric acid (HCl)) or a base (eg potassium hydroxide (KOH)), as known to those skilled in the art.

Another embodiment of planarizing the slurry according to the invention may also be provided with complementary ceramic oxide / metal particles. Such supplemental ceramic oxide / metal particles used in the aqueous slurry may include any one or mixture of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide and germania.

Embodiments of the slurry according to the present invention exhibit a high removal rate for copper when used in a CMP process. More specifically, high copper disk and copper film polishing rates (eg, ˜1000 and 470 nm / min, respectively) were obtained when potassium iodide (KIO ₃ ) was used as the oxidant in the molybdenum oxide slurry. The addition of PAA improved the polishing rate to about 667 nm / min. In addition, the molybdenum sulfide particles are KIO ₃ And a copper film polishing rate of about 750 nm / min was obtained when added to the slurry containing PAA.

While the polishing rate by the KIO ₃ -based slurry of the present invention is high for copper, the post-polished surface of copper is a thick, uneven mist with a roughness value as high as about 150 nm measured by a non-contact optical surface roughness meter. It tends to be covered with layers. If the post-polishing surface quality is desired, the CMP polishing step may be after the buffing step. In one embodiment, the buffing step involves additional polishing of the copper surface using a diluted suspension of H ₂ O ₂ , glycerin, BTA and colloidal silica of deionized water at pH 4. An advantage of using a H ₂ O ₂ -based buffing step is to remove the residual amount of molybdenum oxide that may remain on the surface by reacting H ₂ O ₂ simultaneously with molybdenum oxide. Very clean and smooth copper surfaces are obtained after continuous buffing, some with roughness values as low as 0.35 nm, as measured by non-contact optical surface roughness meters.

Polishing selectivity for one embodiment of the slurry of the present invention between Cu, Ta and silicon oxide (SiO ₂ ) was determined as Cu: Ta: SiO ₂ as 235: 1: 1, as shown in Example 24.

Examples 25 and 26 involve the addition of ethylene diamine tetra acetic acid (EDTA) to test the complex ability of EDTA with copper ions. The polishing rates for the two specified slurry compositions are shown in Table 5.

The following examples are provided to provide further information about the present invention. These examples do not limit the scope of the invention.

Example  1-15

The slurries of Examples 1-15 were used to polish copper disks having a 1.25 inch diameter. The CMP Polisher was an Struers DAP® with IC-1400, k-groove polishing pad. The carrier was fixed (ie not rotated). The rotational speed of the platen was 90 rpm. The down-force placed on the copper disk was 6.3 psi. The flow rate of the slurry was 60 ml / min. Taking into account the density of the Cu material, the polished disk area and the polishing time, the amount of copper removed from the surface of the disk by CMP was determined by measuring the weight difference of the copper disk before and after polishing. The removal rate was then converted to nm of copper removed per minute.

The slurry of Example 1-10 contained all 3% molybdenum oxide in deionized water. The average particle size of molybdenum oxide of Examples 1-10 was 1 micron (1000 nm). The average particle size of molybdenum oxide of Examples 11-15 was 150 nm. As shown in Table 1, various amounts and types of oxidants were added. Example 11 contained 1.5 wt.% MoO ₂ and 3 wt.% Hydroxylamine hydrochloride (((NH ₂ OH) Cl) as oxidant. Example 12 contains 1.5 wt.% MoO ₂ as oxidant. And 3% by weight of gallium permanganate (KMnO ₄ ). Examples 13-15 show varying amounts of MoO ₂ And 3% by weight of KIO3. The slurry pH of Examples 1-15 was adjusted to 4.0 by addition of hydrochloric acid (HCl) or potassium hydroxide (KOH). Slurry compositions and polishing rates for copper disks are shown in Table 1.

Example  16-18

The slurry of Examples 16-18 was used to polish the copper film deposited on the silicon substrate by sputter precipitation. The CMP polishing machine was Westech Model 372 with IC-1400, k-groove polishing pad. The carrier was rotated at a speed of 40 rpm. The platen rotation speed was 40 rpm. The down-force placed on the copper disk was 6 psi. The slurry flow rate was 200 ml / min.

The amount of copper removed from the surface of the silicon substrate was measured by CMP by measuring sheet resistance of the Cu film before and after polishing at 17 points spread throughout the film using a homemade paper mask and a four-point probe. . Sheet resistance was measured at the same point on the film before and after polishing. The sheet resistance measured before and after polishing was then converted for each film thickness before and after polishing based on the resistivity of the Cu material, the applied current and the voltage across the 4-point probe. The difference between the starting and final thickness was calculated as 17 points and the average thickness loss was obtained and then divided by the polishing time to obtain a polishing rate of nm / min.

The slurry contained all 3% molybdenum oxide and 3% by weight potassium iodide (KIO ₃ ) oxidant in deionized water. The average particle size of molybdenum oxide of Examples 16-18 was 1 micron (1000 nm). Example 17 added 1% by weight of PAA to the slurry. Example 18 added 1% by weight of PAA and 1% by weight of molybdenum sulfide (MoS ₂ ). The slurry pH of Examples 16-18 was adjusted to 4.0 by addition of hydrochloric acid (HCl) or potassium hydroxide (KOH). The slurry composition and polishing rate for the copper film are shown in Table 2.

Example  19-23

The slurries of Examples 19-23 were used to polish the copper film deposited on the silicon substrate by sputter precipitation. The diameter of the copper film is 6 inches. The CMP polishing machine was Westech Model 372 with IC-1400, k-groove polishing pad. The carrier was rotated at a speed of 75 rpm. The platen was rotated at 75 rpm. The down-force placed on the copper film was 4 psi. The slurry flow rate was 200 ml / min.

The amount of copper removed from the surface of the silicon substrate was measured by CMP by measuring sheet resistance of the Cu film before and after polishing at 17 points spread throughout the film using a homemade paper mask and a four-point probe. . Sheet resistance was measured at the same point on the film before and after polishing. The sheet resistance measured before and after polishing was then converted for each film thickness before and after polishing based on the resistivity of the Cu material, the applied current and the voltage across the 4-point probe. The difference between the starting and final thickness was calculated as 17 points, the average thickness loss was obtained and then divided by the polishing time to obtain a polishing rate of nm / min.

The slurry contained all 3% molybdenum oxide and 3% by weight potassium iodide (KIO ₃ ) oxidant in deionized water. The average particle diameter of molybdenum oxide of Examples 19-23 was 150 nm. Example 20 added 1 mM benzotriazole (BTA) to the slurry. Example 21 added 1% by weight of PAA to the slurry. Example 22 added 0.1% by weight cetyl pyridinium chloride (CPC) to the slurry. Example 23 added 2 wt% PAA and 1 mM BTA to the slurry. The slurry pH of Examples 19-23 was adjusted to 4.0 by addition of hydrochloric acid (HCl) or potassium hydroxide (KOH). Slurry compositions and polishing rates for copper films are shown in Table 3.

Example  24

Silicon wafers with a 0.3 micron Ta layer precipitated by sputter precipitation (6 inch diameter) and wafers with 1 micron SiO ₂ applied by thermal oxidation were separately polished by a polishing slurry. To determine the removal rate in nm of material removed per minute, the amount of copper and Ta removed was measured using a four-point probe, and SiO ₂ removed from the surface of the silicon wafer by CMP was measured using an optical interferometer. Measured.

The slurry used contained all 3% by weight of molybdenum oxide and 3% by weight of potassium iodide (KIO ₃ ) oxidant in deionized water. The average particle size of molybdenum oxide of Example 24 was 1 micron (1000 nm). The CMP polishing machine was Westech Model 372 with IC-1400, k-groove polishing pad. The carrier was rotated at a speed of 40 rpm. The platen was rotated at 40 rpm. The down-force placed on the copper film was 6 psi. The slurry flow rate was 200 ml / min. Slurry compositions and polishing rates for Cu, Ta and SiO ₂ are shown in Table 4.

Example  25 and 26

The slurries of Examples 25 and 26 were used to polish copper disks having a 1.25 inch diameter. The CMP Polisher was an Struers DAP® with IC-1400, k-groove polishing pad. The carrier was fixed (ie not rotated). The rotational speed of the platen was 90 rpm. The down-force placed on the copper disk was 6.3 psi. The flow rate of the slurry was 60 ml / min. Taking into account the density of the Cu material, the polished disk area and the polishing time, the amount of copper removed from the surface of the disk by CMP was determined by measuring the weight difference of the copper disk before and after polishing. The removal rate was then converted to nm of copper removed per minute.

The slurries of Examples 25 and 26 contained all 3% molybdenum oxide in deionized water. The average particle size of molybdenum oxide of Examples 25 and 26 was 1 micron (1000 nm). As shown in Table 5, various amounts and types of oxidants were added. The slurries of both examples included the addition of 1% by weight of ethylene diamine tetra acetic acid (EDTA) to test the complex ability of EDTA using copper ions. Slurry compositions and polishing rates for copper disks are shown in Table 5.

Another embodiment of the aqueous slurry may include molybdenum trioxide (MoO ₃ ) and an oxidizing agent. The MoO ₃ may be present in an amount of about 0.1 to about 10 weight percent and more preferably about 0.5 to about 5 weight percent, such as about 0.5 to about 10 weight percent. Molybdenum trioxide (MoO ₃ ) is provided in powder form so that molybdenum trioxide (MoO ₃ ) can be visually dissolved in the oxidant. The molybdenum trioxide powder may have an average particle size of about 10,000 nm (10 microns) and more preferably less than about 1,000 nm (1 micron), as measured by Horiba laser dispersion analyzer. Molybdenum trioxide (MoO ₃ ) powder having this size is visually dissolved in an aqueous solution of deionized water and an oxidant. As used herein, the term “dissolved” or “visually dissolved” means a solution that does not require complete dissolution of the particles of MoO ₃ but at least partially dissolves. The solution containing the particles of MoO _3; refers to a solution containing the particles of the MoO ₃ appear to be particles of MoO _3, but is not completely dissolved, when seen with the naked eye "visual dissolved" or substantially clearly dissolved.

Another embodiment of the aqueous slurry may include molybdic acid. Dissolution of molybdenum trioxide in an aqueous solution of deionized water and an oxidant can form molybdate. Molybdate may also be formed by dissolving molybdate in molybdenum metal, molybdenum oxide or oxidation medium. As used herein, the term “molybdic acid” refers to any compound that contains molybdenum and is capable of delivering hydrogen ions in solution. Embodiments of the aqueous slurry of the present invention using molybdenum acid may include the same oxidizing agents, complexing agents, surfactants, corrosion inhibitors, acids or bases and complementary oxidized ceramic / metal particles as listed below for the molybdenum trioxide aqueous slurry. have.

MoO ₃ particles can be prepared from various molybdenum-containing precursor materials, such as ammonium molybdate and related compounds, as well as molybdenum oxide prepared by various methods known in the art, and molybdenum precursors and products are made from particles of various sizes Can be. Molybdenum trioxide particles suitable for use in the present invention are available from a variety of sources, including Climax Molybdenum Company, Madison, Iowa.

The oxidant used with molybdenum trioxide (MoO ₃ ) is hydrogen peroxide (H ₂ O ₂ ), ferric nitrate (Fe (NO ₃ ) ₃ ), potassium iodide (KIO ₃ ), nitric acid (HNO ₃ ), potassium permanganate ( KMnO ₄ ), potassium persulfate (K ₂ S ₂ O ₈ ), ammonium persulfate ((NH ₄ ) ₂ S ₂ O ₈ ), potassium periodate (KIO ₄ ) and hydroxylamine (NH ₂ OH) It may include one or a mixture of. The hydrogen peroxide oxidant may be present at a concentration of about 0.5 to about 20 weight percent H ₂ O ₂ and more preferably about 5 weight percent H ₂ O ₂ , such as about 1 to about 10 weight percent. The ferric nitrate oxidizer is at a concentration of about 0.05 to about 0.2 M Fe (NO ₃ ) ₃ and more preferably about 0.2 M Fe (NO ₃ ) ₃ , such as about 0.1 to about 0.2 M Fe (NO ₃ ) ₃ . May exist. Potassium iodide oxidizer is about 1 to about 3 weight percent KIO ₃ , such as about 1 to about 3 weight percent KIO ₃ And more preferably at a concentration of about 3% KIO ₃ . Nitric acid oxidant, such as about 1 to about 2 weight percent HNO ₃ , about 0.5 to about 2 weight percent HNO ₃ And more preferably in an amount of about 2% by weight HNO ₃ . Potassium permanganate oxidizer, such as about 2 to about 4 weight percent KMnO ₄ , about 1 to about 5 weight percent KMnO ₄ And more preferably in an amount of about 3% KMnO _{4 by} weight. Potassium persulfate oxidizing agent of about 1 to about 5 weight percent K ₂ S ₂ O ₈ and more preferably about 3 weight percent K ₂ S ₂ O ₈ , such as about 2 to about 4 weight percent K ₂ S ₂ O ₈ May be present in amounts. Ammonium persulfate oxidizing agent is about 2 to about 4 wt.% (NH _{4) 2} as S ₂ O _8, about 1 to about 5 parts by weight of (NH _{4) 2} S ₂ O _8, and more preferably about 3 parts by weight (NH ₄ ) May be present in an amount of ₂ S ₂ O ₈ . Potassium periodate oxidant may be present in an amount of about 1 to about 5 weight percent KIO ₄ and more preferably about 3 weight percent KIO ₄ , such as about 2 to about 4 weight percent KIO ₄ . The hydroxylamine oxidant may be present in an amount of about 1 to about 5 weight percent NH ₂ OH and more preferably about 3 weight percent NH ₂ OH, such as about 2 to about 4 weight percent NH ₂ OH.

Composites can also be used in the molybdenum trioxide (MoO ₃ ) aqueous slurry. The combination agent is glycine (C ₂ H ₅ NO ₂ ), alanine (C ₃ H ₇ NO ₂ ), amino butyric acid (C ₄ H ₉ NO ₂ ), ethylene diamine (C ₂ H ₈ N ₂ ), ethylene diamine tetraacetic acid (EDTA ), Ammonia (NH ₃ ), citric acid (C ₆ H ₈ O ₇ ), phthalic acid (C ₆ H ₄ (COOH) ₂ ), oxalic acid (C ₂ H ₂ O ₄ ), acetic acid (C ₂ H ₂ O ₂ ), And any one or mixture of mono, di and tri carboxylic acid series and amino benzoic acid series such as succinic acid (C ₄ H ₆ O ₄ ).

Glycine composite agent is in an amount from about 0.1 to about 3, such as weight% C ₂ H ₅ NO _2, about 0.1 to about 5% by weight of C ₂ H ₅ NO _2, and more preferably from about 0.5 wt.% C ₂ H ₅ NO ₂ May exist. Alanine composite agent is in an amount from about 0.1 to about 3, such as weight% C ₃ H ₇ NO _2, about 0.1 to about 5% by weight of C ₃ H ₇ NO ₂ and more preferably from about 0.5 wt.% C ₃ H ₇ NO ₂ May exist. Amino acid complexes is from about 0.1 to about 3, as weight% C ₄ H ₉ NO _2, about 0.1 to about 5% by weight of C ₄ H ₉ NO _2, and more preferably in an amount of about 0.5 wt% C ₄ H ₉ NO ₂ May exist. Ethylenediamine composite agent is from about 0.1 to about 3, such as weight% C ₂ H ₈ N _2, from about 0.1 to about 5% C ₂ H ₈ weight N _2, and more preferably in an amount of about 0.5 wt% C ₂ H ₈ N ₂ May exist. The ethylene diamine tetra acetic acid composite may be present in an amount of about 0.1 to about 5 weight percent EDTA and more preferably about 0.5 weight percent EDTA, such as about 0.1 to about 3 weight percent EDTA. Ammonia composite agent may be present in an amount from about 0.1 to about 3 wt%, such as NH _3, about 0.1 to about 5% by weight of NH _3, and more preferably from about 0.5 wt.% NH _3. The citric acid complex is in an amount of about 0.1 to about 5 wt% C ₆ H ₈ O ₇ and more preferably about 3 wt% C ₆ H ₈ O ₇ , such as about 0.1 to about 3 wt% C ₆ H ₈ O ₇ May exist. Acid composite agent is from about 0.1 to about 3, such as _{weight% C 6 H 4 (COOH)} 2, about 0.1 to about 5% by weight of C ₆ H ₄ (COOH) _2, and more preferably from about 0.5% C ₆ H ₄ weight ( COOH) ₂ . Oxalate composite agent is in an amount from about 0.1 to about 3, such as weight% C ₂ H ₂ O _4, from about 0.1 to about 5% by weight of C ₂ H ₂ O _4, and more preferably from about 0.5% C ₂ H ₂ O by weight ₄ May exist. Acid composite agent is in an amount from about 0.1 to about 3, such as weight% C ₂ H ₂ O _2, about 0.1 to about 5% by weight of C ₂ H ₂ O _2, and more preferably from about 0.5 wt.% C ₂ H ₂ O ₂ May exist. The succinic acid complex is present in an amount from about 0.1 to about 5 weight percent C ₄ H ₆ O ₄ and more preferably about 0.5 weight percent C ₄ H ₆ O ₄ , such as from 0.1 to about 3 weight percent C ₄ H ₆ O _4. Can be. A composite agent amino acid is such as about 0.1 to about 3 wt% C ₇ H ₇ NO _2, about 0.1 to about 5% by weight of C ₇ H ₇ NO ₂ and more preferably from about 0.5 wt% C ₇ of the H ₇ NO ₂ May be present in amounts.

Embodiments of slurries containing molybdenum trioxide (MoO ₃ ) may also be provided with nonionic surfactants, anionic surfactants or cationic surfactants. The anionic surfactants of the aqueous slurry may comprise polyacrylic acid (PAA), carboxylic acid or salts thereof, sulfate esters or salts thereof, sulfonic acid or salts thereof, phosphoric acid or salts thereof, and sulfosuccinic acid or salts thereof or mixtures thereof. It may include. The cationic surfactant of the aqueous slurry may comprise any one or mixture of primary amines or salts thereof, secondary amines or salts thereof, tertiary amines or salts thereof and quaternary amines or salts thereof. The nonionic surfactant may comprise any one or mixture of many polyethylene glycols.

Optionally, the molybdenum trioxide (MoO ₃ ) aqueous slurry is any one or mixture of heterocyclic organic compounds, including benzotriazole (BTA), benzimidazole, poly triazole, phenyl triazole, thion and derivatives thereof. There may be provided a copper corrosion inhibitor which may include. In addition, the slurry may contain any combination of these surfactants and corrosion inhibitors.

Preferred anionic surfactants used in the MoO ₃ slurry are salts of dodecyl benzene sulfonic acid. The addition of a small amount of dodecyl benzene sulfonic acid (DBSA) anionic surfactant to the slurry significantly reduced the copper coupon dissolution rate of about 0 nm / min and gave a blanket copper wafer polishing rate of about 750 nm / min. . See Example 34. This low copper coupon dissolution rate indicates low dishing of copper lines during pattern wafer polishing. Dodecyl benzene sulfonic acid (DBSA) anionic surfactants and salts thereof, such as about 0.0001 to about 0.5 weight percent (DBSA), from about 0.00001 to about 1 weight percent (DBSA) and more preferably about 0.001 weight percent (DBSA) It may be present in an amount of.

A preferred copper corrosion inhibitor used in MoO ₃ slurries is benzotriazole (BTA). The addition of BTA to the slurry significantly reduced the dissolution rate below 50 nm / min. See Examples 30-33. The benzotriazole (BTA) copper corrosion inhibitor may be present at a concentration of about 1 to about 20 mM BTA and more preferably about 10 mM BTA, such as about 10 mM BTA.

The pH of the MoO ₃ slurry according to the invention may be about 1 to 14 and more preferably about 2.6 pH, such as a pH in the range of about 1 to about 5. The pH of the slurry according to the invention can be adjusted by the addition of a suitable acid (eg acetic acid) or a base (eg potassium hydroxide), as known to those skilled in the art.

Another embodiment of the MoO ₃ polishing slurry according to the present invention is provided with supplemental ceramic oxide / metal particles. Such supplemental ceramic oxide / metal particles used in the aqueous slurry may include any one or mixture of silica, ceria, aluminia, zirconia, titania, magnesia, iron oxide, tin oxide and germania. A preferred supplemental ceramic oxide / metal used in the MoO ₃ slurry is colloidal silicon dioxide (SiO ₂ ). Colloidal silicon dioxide (SiO ₂ ) may have an average particle size of about 20 nm.

Embodiments of the MoO ₃ slurry according to the present invention exhibit high polishing rates for copper when used in a CMP process. More specifically, molybdenum trioxide (MoO ₃ ) particles were dispersed and dissolved in an aqueous solution containing hydrogen peroxide and glycine to obtain a high disk polishing rate (eg, about 2150 nm / min) when used as a copper CMP slurry. However, the copper coupon dissolution rate in this slurry was also high (eg, about 1150 nm / min). See Example 28. One reason the slurry exhibits such high chemical reactivity is the partial dissolution of molybdenum trioxide MoO ₃ nano-particles that form molybdate. The copper dissolution rate indicates the rate at which copper is removed in the region of the wafer that is not mechanically polished. By the inclusion of appropriate concentrations of additives and corrosion inhibitors, the polishing rate can be adjusted to the needs of the user and the dissolution rate can be minimized.

As shown in Examples 29 & 30, the blanket copper wafer polishing rate for one embodiment of the MoO ₃ slurry of the present invention was measured as high as about 1200 nm / min with a post CMP surface roughness of about 1 nm. The slurries of Examples 29 & 30 were filtered to remove particles of about 1,000 nm (1 micron) size and added 1.0 wt% abrasive of 20 nm colloidal SiO ₂ .

The post-polished surface of copper was good with a post CMP surface roughness value of about 1 nm as measured by a non-contact optical surface roughness meter. If it is desired that the surface quality is high after polishing, the CMP polishing step may be after the buffing step. In one embodiment, the buffing step involves additionally polishing the copper surface using deionized water for about 5 to about 15 seconds in a pH range of about 5 to about 7. The advantage of the buffing step with deionized water rinse is the removal of reactive chemicals from the wafer-pad interface, which removes residual amounts of molybdenum oxide that may remain on the surface of the wafer-pad. A clean smooth copper surface is obtained after continuous buffing with deionized water rinse, with some having roughness values as low as about 0.5 to 0.6 nm as measured by a non-contact optical surface roughness meter.

Very high polishing rates (e.g., about 900 nm / min) and very low post CMP roughness (e.g., by appropriate control of the concentration of added chemicals and deionized water rinse for about 5 seconds at the end of wafer polishing) For example, about 0.5 to about 0.6 nm). The copper coupone dissolution rate in this slurry was low (eg about 40 nm / min). When a small amount of anionic surfactant such as sodium dodecyl benzene sulfonate (SDBA) is added to the MoO ₃ polishing slurry, the copper coupon dissolution rate is about 0 nm / min, which results in low dishing of the copper line during pattern wafer polishing. A blanket copper wafer polishing rate of about 750 nm / min was obtained. See Example 34.

A common method for patterned wafer copper polishing is to polish bulk copper at high polishing rates, and then when planarization is achieved, the copper polishing rate is reduced to minimize dishing of the copper lines. By appropriate control of the slurry component components and process parameters, the slurry of the present invention can be adjusted for the general method of polishing at high and low rates.

Example  27 & 28

The slurries of Examples 27 and 28 were used to polish copper disks with a diameter of 32 millimeters (mm). The CMP Polisher was an Struers DAP® with IC-1400, k-groove polishing pad. The carrier was fixed (ie not rotated). The rotational speed of the platen was 90 rpm. The down-force placed on the copper disk was 6.3 psi. The flow rate of the slurry was 60 ml / min. Taking into account the density of the Cu material, the polished disk area and the polishing time, the amount of copper removed from the surface of the disk by CMP was determined by measuring the weight difference of the copper disk before and after polishing. The removal rate was then converted to nm of copper removed per minute.

Copper coupon dissolution experiments were conducted in 500 ml glass beakers containing 400 ml of chemical solution. Copper coupons (ie 99.99% pure) of 25 × 25 × 1 mm size were used as experimental samples. The copper coupon was polished by hand using a 1500 grit sandpatter and washed with diluted hydrochloric acid (HCl) to remove copper oxide from the surface and dried in an air stream and then weighed. The solution was then stirred while the copper coupon was then immersed in the solution for 3 minutes. After the experiment, the copper coupon was washed repeatedly with deionized water rinse and dried in airflow to weigh it. Weight loss was used to calculate the dissolution rate.

Example 27 contains 1.0 wt.% MoO ₃ in deionized water (DI) and Example 28 is deionized water (DI) with 5.0 wt.% H ₂ O ₂ and 1.0 wt.% Glycine, respectively, as oxidant and complexing agent. ) Contained 1.0% by weight MoO ₃ . Example 27 The natural pH of the slurry was about 1.8. Example 28 The natural pH of the slurry was about 2.6. The remaining proportion not specified in the table below for the slurry composition is the proportion of deionized water. In Example 27, the MoO ₃ comprises a slurry composition of 1% and the deionized water comprises a remaining 99% slurry composition. The slurry composition, copper coupon dissolution rate and polishing rate for the copper disks of Examples 27 and 28 are shown in Table 6.

Example  29-34

The slurries of Examples 29-34 were used to polish the copper film deposited on the silicon substrate by sputter precipitation. The diameter of the copper film is 6 inches. The CMP polishing machine was Westech Model 372 with IC-1400, k-groove polishing pad. The carrier was rotated at a speed of 75 rpm. The platen was rotated at 75 rpm. The down-force placed on the copper film was 4 psi. The slurry flow rate was 200 ml / min.

The amount of copper removed from the surface of the silicon substrate was measured by CMP by measuring sheet resistance of the Cu film before and after polishing at 17 points spread throughout the film using a homemade paper mask and a four-point probe. . Sheet resistance was measured at the same point on the film before and after polishing. The sheet resistance measured before and after polishing was then converted for each film thickness before and after polishing based on the resistivity of the Cu material, the applied current and the voltage across the 4-point probe. The difference between the starting and final thickness was calculated as 17 points and the average thickness loss was obtained and then divided by the polishing time to obtain a polishing rate of nm / min.

Copper coupon dissolution experiments were conducted in 500 ml glass beakers containing 400 ml of chemical solution. Copper coupons (ie 99.99% pure) of 25 × 25 × 1 mm size were used as experimental samples. The copper coupon was polished by hand using a 1500 grit sandpatter and washed with diluted hydrochloric acid (HCl) to remove copper oxide from the surface and dried in an air stream and then weighed. The solution was then stirred while the copper coupon was then immersed in the solution for 3 minutes. After the experiment, the copper coupon was washed repeatedly with deionized water rinse and dried in airflow to weigh it. Weight loss was used to calculate the dissolution rate.

The slurries of Examples 29-34 contained 0.5% by weight molybdenum trioxide (MoO ₃ ) in deionized water. At the end of wafer polishing, deionized water rinse was applied for 5 seconds. Example 29 is 0.5% MoO ₃ + 5.0% H ₂ O ₂ + 5 mM BTA + 1.0% SiO ₂ filtered by a 1.0% glycine + 100 nm filter. Example 29 The natural pH of the slurry was about 2.9. Example 30 is 0.5% MoO ₃ + 5.0% H ₂ O ₂ + 10 mM BTA + 1.0% SiO ₂ filtered by a 1.0% glycine + 100 nm filter. Example 30 The natural pH of the slurry was about 2.9. Example 31 is 0.5% MoO ₃ + 5.0% H ₂ O ₂ + 10 mM BTA + 0.1% SiO ₂ filtered by 0.5% glycine + 100 nm filter. Example 31 The slurry had a natural pH of about 2.6. Example 32 is 0.5% MoO ₃ + 5.0% H ₂ O ₂ + 10 mM BTA + 0.5% SiO ₂ filtered by 0.5% glycine + 100 nm filter. Example 32 The slurry had a natural pH of about 2.6. Example 33 is 0.5% MoO ₃ + 5.0% H ₂ O ₂ + 10 mM BTA + 1.0% SiO ₂ filtered by 0.5% glycine + 100 nm filter. Example 33 The slurry had a natural pH of about 2.6. Example 34 comprises 0.5% MoO ₃ + 5.0% H ₂ O ₂ + It contained 0.001% SDBS filtered by 0.5% glycine + 10 mM BTA + 100 nm filter. Example 34 The slurry had a natural pH of about 2.6. The average particle size of SiO ₂ of the Examples 29-34 slurry was about 20 nm. The remaining proportion not specified in the table below for the slurry composition is the proportion of deionized water of the slurry. The slurry composition and polishing rate for copper wafers along with the copper coupon dissolution rates for Examples 29-34 are shown in Table 7.

Example  35-37

The slurries of Examples 35-37 were used to polish the 6 inch copper blanket film. The CMP polishing machine was Westech Model 372 with IC-1400, k-groove polishing pad. The carrier was rotated at a speed of 75 rpm. The platen was rotated at 75 rpm. The down-force placed on the copper blanket film was 4.0 psi. The slurry flow rate was 200 ml / min.

The amount of copper removed from the surface of the silicon substrate was measured by CMP by measuring sheet resistance of the Cu film before and after polishing at 17 points spread throughout the film using a homemade paper mask and a four-point probe. . Sheet resistance was measured at the same point on the film before and after polishing. The sheet resistance measured before and after polishing was then converted for each film thickness before and after polishing based on the resistivity of the Cu material, the applied current and the voltage across the 4-point probe. The difference between the starting and final thickness was calculated as 17 points and the average thickness loss was obtained and then divided by the polishing time to obtain a polishing rate of nm / min.

Copper coupon dissolution experiments were conducted in 500 ml glass beakers containing 400 ml of chemical solution. Copper coupons (ie 99.99% pure) of 25 × 25 × 1 mm size were used as experimental samples. The copper coupon was polished by hand using a 1500 grit sandpatter and washed with diluted hydrochloric acid (HCl) to remove copper oxide from the surface and dried in an air stream and then weighed. The solution was then stirred while the copper coupon was then immersed in the solution for 3 minutes. After the experiment, the copper coupon was washed repeatedly with deionized water rinse and dried in airflow to weigh it. Weight loss was used to calculate the dissolution rate.

Example 35 is 1% MoO ₃ + 5.0% H ₂ O ₂ + 5 mM BTA + 1.0% SiO ₂ filtered by a 1.0% glycine + 100 nm filter. Example 35 The slurry had a natural pH of about 2.9. Example 36 is 1% MoO ₃ + 5.0% H ₂ O ₂ + 10 mM BTA + 1.0% SiO ₂ filtered by a 1.0% glycine + 100 nm filter. Example 36 The slurry had a natural pH of about 2.9. Example 37 is 1% MoO ₃ + 5.0% H ₂ O ₂ + 15 mM BTA + 1.0% SiO ₂ filtered by a 1.0% glycine + 100 nm filter. Example 37 The slurry had a natural pH of about 2.9. The remaining proportion not specified in the table below for the slurry composition is the proportion of deionized water of the slurry. The slurry composition and polishing rate for copper wafers along with the copper coupon dissolution rate for Examples 29-34 are shown in Table 8.

As shown by the dislocation planarization curves in the figure, the open circuit potential of copper coupone of MoO ₃ slurry is better than that of tantalum coupone, which indicates that galvanic corrosion of copper prevents dishing of copper lines. Pattern to be minimized Indicates no problem during wafer polishing. Detailed experimental results are as follows. EG & G model Potentiostat / Galvanostat was used to perform the displacement potential planarization experiment. A three-electrode arrangement consisting of a working electrode (Cu / Ta Coupon), a platinum counter electrode and a saturated scarlet electrode (SCE) was used as reference electrode. The three electrodes are immersed in 250 ml of chemical solution, the potential of the working electrode is scanned from about -750 mV to about 1000 mV wrt open circuit potential (OCP), and the resulting current density is measured using the EG & G Princeton Applied Research model 352 softcorr ™ II corrosion software. To monitor.

A common method of patterned wafer polishing is to bulk bulk copper at high polishing rates, and then when planarization is achieved, the copper is removed at low polishing rates to minimize dishing of the copper lines. MoO ₃ of the present invention, by appropriate control of the slurry component components and process parameters The slurry can be adjusted for common polishing methods at high and low speeds. Same MoO ₃ Tantalum dissolution and disk polishing rate by slurry were both less than 5 nm / minute. High copper blanket wafer removal rate, high selectivity to tantalum, good post CMP surface finish and low abrasive content reduce the number of post CMP defects and facilitate CMP surface cleaning, bringing this slurry to the first stage of the copper CMP process. Make it an interesting candidate.

In summary, the claimed products and processes collectively represent important advances in CMP technology. The products and processes described above are new, excellent and very beneficial from a technical and pragmatic point of view. Appropriate variations are possible from the preferred embodiments presented in the present invention.

Claims (25)

      An aqueous polishing slurry for chemical-mechanical planarization comprising molybdenum oxide and an oxidizing agent. The aqueous polishing slurry of claim 1, wherein the molybdenum oxide is MoO ₂ . The aqueous polishing slurry of claim 1, wherein the molybdenum oxide is MoO ₃ . The method of claim 2 or 3, wherein the polishing slurry is MoO ₂ And from about 0.1% to about 10% by weight of the MoO ₃ particles.       4. The aqueous polishing slurry of claim 2 or 3, wherein the oxidant comprises at least one selected from the group consisting of ferric nitrate, potassium iodide, nitric acid and potassium permanganate.       4. The slurry according to claim 2 or 3, wherein the slurry is selected from the group consisting of polyacrylic acid, carboxylic acid or salt thereof, sulfate ester or salt thereof, sulfonic acid or salt thereof, phosphoric acid or salt thereof and sulfosuccinic acid or salt thereof. An aqueous polishing slurry further comprising an anionic surfactant.       The cationic surfactant according to claim 2 or 3, wherein the slurry is selected from the group consisting of primary amines or salts thereof, secondary amines or salts thereof, tertiary amines or salts thereof and quaternary amines or salts thereof. An aqueous polishing slurry further comprising.       4. The aqueous polishing slurry of claim 2 or 3, wherein the slurry further comprises one or more supplemental ceramic oxide / metal particles.       The aqueous polishing slurry of claim 2, wherein the oxidant comprises at least one selected from the group consisting of potassium iodide and hydroxylamine hydrochloride.       4. The aqueous polishing slurry of claim 3 wherein said oxidant comprises at least one selected from the group consisting of hydrogen peroxide, potassium persulfate, ammonium persulfate, potassium periodate and hydroxylamine.       4. The aqueous polishing slurry of claim 3 wherein the slurry further comprises one or more nonionic surfactants selected from the group consisting of polyethylene glycol. The provision of MoO ₃ ; And A method of making MoO ₂ comprising heating the provided MoO ₃ for about 30 to about 180 minutes in a reducing environment at a temperature of about 400 ° C. to about 700 ° C.      A method of polishing a copper by chemical-mechanical planarization comprising polishing the copper using a polishing pad and an aqueous slurry comprising molybdenum oxide and an oxidant. The method of claim 13, wherein the molybdenum oxide is MoO ₂ . The method of claim 13, wherein the molybdenum oxide is MoO ₃ . The method of claim 14 or 15, wherein the polishing slurry is MoO ₂ And from about 0.1% to about 10% by weight of the MoO ₃ particles.       16. The method of claim 14 or 15, wherein the oxidant comprises at least one selected from the group consisting of ferric nitrate, potassium iodide, nitric acid and potassium permanganate.       16. The slurry according to claim 14 or 15, wherein the slurry is selected from the group consisting of polyacrylic acid, carboxylic acid or salt thereof, sulfate ester or salt thereof, sulfonic acid or salt thereof, phosphoric acid or salt thereof and sulfosuccinic acid or salt thereof. The method further comprises an anionic surfactant.       The cationic surfactant according to claim 14 or 15, wherein the slurry is selected from the group consisting of primary amines or salts thereof, secondary amines or salts thereof, tertiary amines or salts thereof and quaternary amines or salts thereof. How to include more.       16. The method of claim 14 or 15, wherein the slurry further comprises one or more supplementary ceramic oxide / metal particles.       The method of claim 14, wherein the oxidant comprises one or more selected from the group consisting of potassium iodide and hydroxylamine hydrochloride.       The method of claim 15 wherein the oxidant comprises at least one selected from the group consisting of hydrogen peroxide, potassium persulfate, ammonium persulfate, potassium periodate and hydroxylamine.       The method of claim 15, wherein the slurry further comprises one or more nonionic surfactants selected from the group consisting of polyethylene glycol. Molten MoO ₃ And providing a slurry of high polishing rate comprising an oxidizing agent;       Polishing copper using a slurry of high polishing rate; Providing a low polishing slurry comprising dissolved MoO ₃ , an oxidant and a corrosion inhibitor; And         And additionally polishing the copper using a slurry of low polishing rate.       An aqueous slurry for chemical-mechanical planarization comprising molybdate.

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