Iodate-containing chemical-mechanical polishing compositions and methods

The present invention relates to a composition for chemical mechanical polishing and a method for polishing a base material using the composition.

The development of next-generation semiconductor devices has led to the use of metals with lower resistance values, such as copper, than previous-generation metals, in order to reduce the capacitance between conductive layers on the device and increase the frequency at which circuits can operate. The emphasis is on. One method of making flat copper circuit traces on a silicon dioxide substrate is called the damascene process. Following this process, the dielectric surface of silicon dioxide is patterned by a conventional dry etch process to form holes and trenches for vertical and horizontal interconnection. The patterned surface is coated with an adhesion promoting layer such as tantalum or titanium and / or a diffusion barrier layer such as tantalum nitride or titanium nitride. The adhesion promoting layer and / or the diffusion barrier layer is then overcoated with a copper layer. Chemical mechanical polishing reduces the thickness of the copper topcoat layer and the thickness of any adhesion-promoting layer and / or diffusion barrier layer until a flat surface is obtained with the raised portion of the silicon dioxide surface exposed. Vias and trenches remain filled with conductive copper that forms the interconnects of the circuit.

Tantalum and tantalum nitride are particularly suitable materials for use in damascene processes as adhesion-promoting layers and / or diffusion barrier layers for copper-based devices. However, the properties of tantalum and tantalum nitride are very chemically inert, unlike those of copper, so polishing compositions useful for polishing copper are not suitable for removing underlying tantalum and tantalum nitride. In many cases. Typically, in tantalum polishing, a high solid content, ie, greater than 5 wt%, based on the total mass of the oxidant, such as hydrogen peroxide, and the composition, to achieve a useful removal rate. A composition containing an abrasive is required. However, hydrogen peroxide is a strong oxidant that can react with other components of the polishing composition, limiting the stability of the polishing composition and thus limiting the useful pot life of the polishing composition. To do. Therefore, hydrogen peroxide is typically added to the polishing composition by the end user. That is, hydrogen peroxide is used in so-called "two-pot" compositions that require an additional mixing step in the polishing operation. In addition, strong oxidants such as hydrogen peroxide can erode the copper wire on the surface of the substrate by chemical etching. High content solids or abrasives are also problematic. For example, high solid content can create defects on the surface of the substrate, adversely affecting the performance of any integrated circuit layer produced from the substrate and the selectivity of tantalum for silicon dioxide. Can be reduced. In addition, polishing compositions with a high solid content are expensive to produce.

<p> Therefore, there is a need for improved polishing compositions and methods for substrates containing tantalum and copper that are cost effective and reduce the overall processing time, for example by increasing the rate of removal of tantalum.</p>

<p> The present invention is a composition for chemical mechanical polishing for polishing a substrate, wherein (a) 0.05 wt% to 10 wt% abrasive and (b) 0.05 wt% to 4 wt% iodic acid anion. And (c) nitrogen-containing C_4-20Heterocycle and C_1-20A composition containing 0.01 wt% to 1 wt% nitrogen-containing compound selected from the group consisting of alkylamines and (d) a liquid carrier containing water, and the pH of the chemical mechanical polishing composition is 1 to 5. A chemical mechanical polishing composition for polishing a substrate is provided.</p><p> The present invention relates to (a) a step of preparing a base material, (b) the base material as a polishing pad and a composition for chemical mechanical polishing, and (i) 0.05 wt% to 10 wt% of an abrasive. (Ii) 0.05 wt% to 4 wt% iodic acid anion and (iii) nitrogen-containing C_4-20Heterocycle and C_1-20A chemical containing 0.01 wt% to 1 wt% nitrogen-containing compound selected from the group consisting of alkylamines and a liquid carrier containing (iv) water, wherein the chemical mechanical polishing composition has a pH of 1 to 5. A step of contacting the composition for mechanical polishing, (c) a step of moving the polishing pad against the substrate by placing the composition for chemical polishing between them, and (d) at least one of the substrates. Further provided is a method of chemically mechanically polishing a substrate, which comprises a step of scraping a portion to polish the substrate.</p>

The present invention provides a chemical mechanical polishing composition for polishing a substrate. The polishing composition comprises (a) an abrasive, (b) an iodate ion, (c) a nitrogen-containing compound, and (d) a liquid carrier containing water. This polishing composition preferably allows for higher and adjustable metal removal rates at relatively lower abrasive concentrations.

The polishing composition is iodate ion (IO).₃^-)including. Iodic acid ion acts as an oxidant. Iodic acid ions can be present in the polishing composition in any suitable amount. Iodic acid ions are typically contained in the polishing composition in an amount of 0.01 wt% or more, preferably 0.05 wt% or more, more preferably 0.1 wt% or more, based on the total mass of the polishing composition. Exists in. Iodic acid ions are typically for polishing in an amount of 4 wt% or less, preferably 2 wt% or less, more preferably 1 wt% or less, most preferably 0.4 wt% or less, based on the total mass of the polishing composition. Present in the composition.

Iorate ions are obtained in solution by dissolving any suitable technique, typically any suitable iodate, in water. Examples of iodates include, but are not limited to, sodium iodate, potassium iodate, ammonium iodate, calcium iodate, cesium iodate, lithium iodate, and magnesium iodate. Alternatively, the iodic acid ion is obtained by dissolving iodic acid in water.

Desirably, iodate ions are more stable than peroxide oxidants. Therefore, the polishing composition containing iodate ions can be supplied to the end user as a single package system, i.e., a so-called "one-pot" composition.

The polishing composition further comprises a nitrogen-containing compound. The nitrogen-containing compound can be any suitable nitrogen-containing compound. The choice of nitrogen-containing compound is typically dependent on the particular substrate to be polished. Typically, the nitrogen-containing compound is a nitrogen-containing C._4-20Heterocycle or C_1-20It is an alkylamine. Preferably, the nitrogen-containing compound is 1H-1,2,3-benzotriazole, 1H-1,2,3-benzotriazole-5-carboxylic acid, 1,2,4-triazole, 5-methyl-1H-benzo. Triazole, 4-amino-1,2,4-triazole, 1H-benzotriazole-1-carboxyaldehyde, 3-amino-1,2,4-triazole-5-carboxylic acid, pyrazole, 2-pyrazinecarboxylic acid, 2 , 6-pyridinecarboxylic acid, 4-pyridylacetic acid, 1H-1,2,3-triazoro [4,5-b] pyridine, methylamine, trimethylamine, ethylamine, triethylamine, salts thereof, and combinations thereof. Will be selected. In a preferred embodiment, the nitrogen-containing compound is 1H-1,2,3-benzotriazole, 5-methyl-1H-benzotriazole or a combination thereof.

The nitrogen-containing compound can be present in any suitable amount. The nitrogen-containing compound is typically contained in the polishing composition in an amount of 0.01 wt% or more, preferably 0.05 wt% or more, more preferably 0.1 wt% or more, based on the total mass of the polishing composition. Exists in. The nitrogen-containing compound is typically present in the polishing composition in an amount of 1 wt% or less, preferably 0.5 wt% or less, more preferably 0.25 wt% or less, based on the total mass of the polishing composition. To do.

It was surprisingly found that the tantalum removal rate of the composition of the present invention containing the nitrogen-containing compound and the iodate ion was higher than that of other oxidizing agents. It is expected that the overall processing time will be reduced by increasing the removal rate in the polishing of tantalum.

The polishing composition further comprises an abrasive. Significantly, it was found that high tantalum removal rates could be achieved using a chemical mechanical polishing composition containing a relatively low solid content along with an iodate oxidant. The abrasive is typically present in the polishing composition in an amount of 0.05 wt% or greater (eg, 0.1 wt% or greater or 0.25 wt% or greater) based on the total mass of the abrasive composition. .. Abrasives are typically 10 wt% or less (eg, 5 wt% or less, 2 wt% or less, 1 wt% or less, 0.75 wt% or less or 0.5 wt% or less) based on the total mass of the polishing composition. It is present in the polishing composition in quantity.

The abrasive can be any suitable abrasive, many of which are well known in the art. Abrasives preferably contain metal oxides. Suitable metal oxides include alumina, silica, titania, ceria, zirconia, germania, magnesia, co-formed products thereof, and metal oxides selected from the group consisting of combinations thereof. Preferably, the metal oxide is silica. The silica can be any suitable form of silica. Useful forms of silica include, but are not limited to, fumed silica, precipitated silica, and polycondensed silica. Most preferably, the silica is polycondensation silica. Polycondensation silica particles are typically Si (OH).₄Is prepared by condensing to form colloidal particles. Such abrasive particles can be prepared in accordance with US Pat. No. 5,230,833, or various commercially available products such as Fuso PL-1 and Pl-2 products. It can be obtained as any of Akzo-Nobel Bindzil 50/80 products, as well as Nalco 1050, 2327 and 2329 products, as well as other similar products available from DuPont, Bayer, Abrasive Research, Nissan Chemical and Clariant.

Abrasive particles can have any suitable size. Typically, the abrasive particles have an average particle size (eg, average particle size) of 5 nm to 250 nm. Preferably, the abrasive particles have an average particle size of 10 nm to 100 nm. Most preferably, the abrasive particles have an average particle size of 25 nm to 80 nm. The particle size of a non-spherical particle is the diameter of the smallest sphere that surrounds the particle.

Liquid carriers are used to facilitate the application of abrasives and any components dissolved or suspended in it to the surface of a suitable substrate to be polished (eg, flattened). Liquid carriers are typically aqueous carriers, which can be water-only (ie, can consist of water), can be essentially from water, or have good miscibility with water. It can contain a solvent or can be an emulsion. Suitable water-miscible solvents include alcohols such as methanol, ethanol and the like, as well as ethers such as dioxane and tetrahydrofuran. Aqueous carriers preferably contain water, more preferably deionized water, become essentially water or consist of water.

The polishing composition can have any suitable pH. For example, the polishing composition can have a pH of 1-5. Typically, the polishing composition has a pH of 2 or higher. The pH of the polishing composition is typically 4 or less.

The pH of the polishing composition can be achieved and / or maintained by any suitable means. More specifically, the polishing composition can further include a pH regulator, a pH buffer, or a combination thereof. The pH regulator can be any suitable pH regulator compound. For example, the pH regulator can be nitric acid, potassium hydroxide or a combination thereof. The pH buffer can be any suitable buffer, such as phosphates, sulfates, acetates, borates, ammonium salts and the like. The polishing composition can contain any suitable amount of pH regulator and / or pH buffer. However, an amount suitable for achieving and / or maintaining the pH of the polishing composition within the pH range described herein must be used.

The polishing composition optionally contains a corrosion inhibitor (ie, a film-forming agent). The corrosion inhibitor can be any suitable corrosion inhibitor for any one or more components of the substrate. Preferably, the corrosion inhibitor is a copper corrosion inhibitor. For the purposes of the present invention, the corrosion inhibitor is any compound or compound that facilitates the formation of a passivation layer (ie, anti-dissolution layer) on at least a portion of the surface to be polished. Is a mixture of. The polishing system of the present invention may contain any suitable amount of corrosion inhibitor. Generally, polishing-based polishing compositions contain 0.005 wt% to 1 wt% (eg, 0.01 to 0.5 wt% or 0.02 to 0.2 wt%) corrosion inhibitors.

The polishing composition further optionally further comprises one or more other additives. The polishing composition can include a surfactant and / or a rheology control agent, such as a viscosity enhancer and a coagulant (eg, a polymeric rheology control agent, such as a urethane polymer). Suitable surfactants include, for example, cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, fluorinated surfactants, mixtures thereof and the like.

Polishing compositions, many of which can be prepared by any suitable technique known to those of skill in the art. The polishing composition can be prepared in batch or in a continuous process. In general, polishing compositions can be prepared by combining their components in any order. As used herein, the term "ingredient" is optional for individual components (eg, nitrogen-containing compounds, abrasives, etc.) and multiple components (eg, nitrogen-containing compounds, iodic acid ion sources, surfactants, etc.). Including combinations of.

For example, the abrasive can be dispersed in a suitable liquid carrier. An iodic acid ion source and a nitrogen-containing compound can then be added and these components can be mixed by any method that can be incorporated into the polishing composition. The polishing composition is one or more components added to the polishing composition immediately before use (eg, within 1 minute before use, within 1 hour before use, or within 7 days before use), such as iodic acid. It can be prepared before use with an ion source. Polishing compositions can also be prepared by mixing these components on the surface of the substrate during the polishing operation.

The polishing composition can be supplied as one package system containing an iodic acid ion source, a nitrogen-containing compound, an abrasive, and a liquid carrier. Alternatively, the abrasive can be supplied in the first container as a dispersion in the liquid carrier and the iodic acid ion source is in a dry form or in the second container as a solution or dispersion in the liquid carrier. Can be supplied. Nitrogen-containing compounds can be placed in first and / or second or third containers. Furthermore, the components in the first or second container can be in the dry form, while the components in the remaining one or more containers can be in the form of an aqueous dispersion. Furthermore, it is appropriate that the components in the first or second container have different pH values or have substantially similar or equal pH values. The iodate oxidant can be supplied separately from the other components of the polishing composition, eg, used by the end user immediately prior to use (eg, within 1 week prior to use, within 1 day prior to use). Within 1 hour before use, within 10 minutes before use or within 1 minute before use), it can be combined with other components of the polishing composition. The combination of the other two containers or three or more containers of the components of the polishing composition is within the knowledge of those skilled in the art.

In a preferred embodiment, the polishing composition is supplied as a single package system.

The polishing composition of the present invention can also be provided as a concentrate intended to be diluted with an appropriate amount of liquid carrier prior to use. In such an embodiment, the concentrate of the polishing composition is such that when the concentrate is diluted with an appropriate amount of liquid carrier, each component of the polishing composition is within the appropriate range described above for each component. Abrasives, iodate ions, nitrogen-containing compounds and liquid carriers can be included in such amounts as present in the polishing composition. For example, the abrasive, iodate ion and nitrogen-containing compounds are present in the concentrate in an amount of twice (eg, 3 times, 4 times or 5 times) the concentration described above for each component, respectively, and are concentrated. When the compound is diluted with an equal amount of liquid carrier (eg, 2x equal amount liquid carrier, 3x equal amount liquid carrier or 4x equal amount liquid carrier, respectively), each component is contained in the polishing composition. The ingredients can be made to be present in an amount within the range described above. In addition, as will be appreciated by those skilled in the art, concentrates to ensure that iodate ions, nitrogen-containing compounds and other suitable additives are at least partially or completely dissolved in the concentrate. Can contain an appropriate proportion of liquid carriers present in the final polishing composition.

The present invention also provides a method of polishing a substrate with the polishing composition described herein. The method for polishing the base material is (i) a step of bringing the base material into contact with the above-mentioned polishing composition, and (ii) a step of scraping or removing at least a part of the base material to polish the base material. including.

In particular, the present invention relates to (a) a step of preparing a base material, (b) a polishing pad and a composition for chemical mechanical polishing, and (i) polishing 0.05 wt% to 10 wt% of the base material. Agent, (ii) 0.05 wt% to 4 wt% iodic acid anion, and (iii) nitrogen-containing C_4-20Heterocycle and C_1-20A chemical containing 0.01 wt% to 1 wt% nitrogen-containing compound selected from the group consisting of alkylamines and a liquid carrier containing (iv) water, wherein the chemical mechanical polishing composition has a pH of 1 to 5. A step of contacting the composition for mechanical polishing, (c) a step of moving the polishing pad against the substrate by placing the composition for chemical polishing between them, and (d) at least one of the substrates. Further provided is a method of chemically mechanically polishing a substrate, which comprises a step of scraping a portion to polish the substrate.

Although the polishing composition of the present invention is useful for polishing any base material, this polishing composition is particularly useful for polishing a base material containing at least one metal layer containing tantalum. The substrate can be any suitable tantalum-containing substrate (eg, integrated circuit, metal, ILD layer, semiconductor and thin film) and any suitable insulating layer and / or other metal or metal alloy layer (eg, eg. , Metal conductive layer) can be further included. The insulating layer can be a metal oxide, glass, organic polymer, fluorinated organic polymer or any other suitable high or low k insulating layer. The insulating layer is preferably a silicon-based metal oxide. The additional metal or metal alloy layer can be any suitable metal or metal alloy layer. The tantalum-containing base material preferably further contains a metal layer containing copper.

According to the present invention, the substrate can be flattened or polished with the polishing composition described herein by any suitable technique. The polishing method of the present invention is particularly suitable for use with a chemical mechanical polishing (CMP) apparatus. Typically, a CMP device has a platen that moves in use and has a velocity resulting from orbital, linear or circular motion, a polishing pad that comes into contact with the platen and moves with it as the platen moves, and the surface of the polishing pad. Includes a carrier that holds the substrate to be polished by contacting and moving against. Polishing of the base material is performed by contacting the base material with the polishing pad and the polishing composition of the present invention, and then the polishing pad is moved with respect to the base material to scrape at least a part of the base material to remove the base material. Try to polish.

The substrate can be flattened or polished with the polishing composition along with any suitable polishing pad (eg, polishing surface). Suitable polishing pads include, for example, woven and non-woven polishing pads. In addition, suitable polishing pads can include any suitable polymer of varying density, hardness, thickness, compressibility, repulsive force against compression, and compressive modulus. Suitable polymers include, for example, polyvinyl chloride, polyvinyl fluoride, nylon, carbon fluoride, polycarbonate, polyester, polyacrylate, polyether, polyethylene, polyamide, polyurethane, polystyrene, polypropylene, their co-formed products, and theirs. Can be mentioned.

Desirably, the CMP apparatus further includes an in situ polishing end point detection system, many of which are known in the art. Techniques for inspecting and monitoring the polishing process by analyzing the light or other radiation reflected from the surface of the workpiece are known in the art. Such methods include, for example, US Pat. Nos. 5,196,353, 5,433,651, 5,609,511, 5,643,046. Specification, No. 5,658,183, No. 5,730,642, No. 5,838,447, No. 5,872,633, No. 5 , 893, 796, 5,949,927, and 5,964,643. Desirably, checking or monitoring the progress of the polishing process for the workpiece to be polished allows determination of the polishing end point, i.e., when to end the polishing process for a particular workpiece.

The invention will be further described by the following examples, but of course these examples should not be construed as limiting the scope of the invention in any way.

In each of the examples below, tantalum, copper and TEOS blanket wafers were polished with different polishing compositions using conventional CMP equipment. The polishing equipment was as follows. The downward force of the substrate on the carrier against the polishing pad on the platen was 9.3 kPa (1.35 psi), the platen speed was 110 rpm, the carrier speed was 102 rpm, and the flow rate of the polishing composition was 150 ml / min. Following polishing, the rate of removal of tantalum, copper and dielectric oxides from the blanket wafer was measured in Å / min.

[Example 1] This example evaluates the effect of iodate concentration on the removal rate of tantalum, copper and dielectric oxides using the polishing composition of the present invention.

Similar substrates, including tantalum, copper and TEOS blanket layers, were polished with six different polishing compositions (polishing compositions 1A, 1B, 1C, 1D, 1E and 1F). Each polishing composition contained 0.5 wt% polycondensation silica (80 nm in diameter) and 0.1 wt% benzotriazole in water at pH 2.4. The polishing compositions 1A to 1F contain 0.01 wt%, 0.025 wt%, 0.05 wt%, 0.1 wt%, 0.2 wt% and 0.25 wt% KIO, respectively.₃Was further included. The results of the removal rates of tantalum, copper and TEOS are shown in Table 1.

<tables num="1"></tables>

These results demonstrate that the rate of removal of dielectric oxide (TEOS) is largely independent of the concentration of iodate. In contrast, the rate of removal of tantalum and copper is strongly dependent on the concentration of iodate. The rate of copper removal increases with increasing iodate concentration. The removal rate of tantalum reaches a maximum of more than 1000 Å / min at an intermediate iodate concentration of around 0.1 wt%. High tantalum removal rates above 1000 Å / min cannot be achieved with conventional oxidants at similarly low abrasive content, eg 0.5 wt%.

[Example 2] In this example, the polishing composition of the present invention is used to evaluate the effect of the abrasive concentration on the removal rate of tantalum, copper and dielectric oxide.

Similar substrates, including tantalum, copper and TEOS blanket layers, were polished with five different polishing compositions (polishing compositions 2A, 2B, 2C, 2D and 2E). Each polishing composition has a 0.05 wt% KIO₃And 0.1 wt% benzotriazole (BTA) was contained in water at pH 2.4. The polishing compositions 2A-2E further contained 0.25 wt%, 0.5 wt%, 1 wt%, 1.5 wt% and 2 wt% polycondensation silica (80 nm in diameter), respectively. Table 2 shows the removal rates of tantalum, copper and TEOS.

<tables num="2"></tables>

These results demonstrate that the rate of removal of dielectric oxide (TEOS) is strongly dependent on the concentration of the abrasive. In contrast, the rate of removal of tantalum and copper is relatively independent of the concentration of the abrasive. The graph of FIG. 1 shows the Ta / TEOS selectivity as a function of the abrasive concentration. This graph demonstrates high Ta / TEOS selectivity at lower abrasive concentrations.

[Example 3] This example evaluates the dependence of material removal rate on pH.

Similar substrates, including tantalum, copper and TEOS blanket layers, were polished with six different polishing compositions (polishing compositions 3A, 3B, 3C, 3D, 3E and 3F). Each polishing composition is 0.1 wt% KIO₃, 0.1 wt% BTA and 0.5 wt% polycondensed silica (diameter 80 nm). The pH of the polishing composition 3A is 2.19, the pH of the polishing composition 3B is 2.45, the pH of the polishing composition 3C is 2.6, the pH of the polishing composition 3D is 2.8, for polishing. The pH of the composition 3E was 3.12, and the pH of the polishing composition 3F was 3.67. The results of the removal rates of tantalum, copper and TEOS are shown in Table 3.

<tables num="3"></tables>

These results are KIO₃Demonstrates a strong dependence of tantalum, copper and TEOS removal rates on the pH of polishing compositions containing.

[Example 4] In this example, the effect of the nitrogen-containing compound on the removal rate of tantalum and copper is evaluated using the polishing composition of the present invention.

Similar substrates, including tantalum and copper blanket layers, were polished with five different polishing compositions (polishing compositions 4A, 4B, 4C, 4D and 4E). Each polishing composition has a 0.05 wt% KIO₃And 0.5 wt% polycondensation silica (diameter 80 nm) was contained in water at pH 2.6. The polishing composition 4A does not contain benzotriazole ("BTA"), and the polishing compositions 4B-4E contain 0.025 wt%, 0.05 wt%, 0.1 wt% and 0.2 wt% BTA, respectively. Was further included. Table 4 shows the results of the removal rates of tantalum and copper.

<tables num="4"></tables>

BTA is a well-known inhibitor of copper removal. However, as is clear from the results shown in Table 4, BTA increased the rate of tantalum removal in combination with iodate. The removal rate of tantalum increased with increasing BTA concentration and reached a flat region at a BTA concentration of 0.1 wt%. The polishing composition 4D exhibited a tantalum removal rate about 60% higher than that observed for the polishing composition without BTA, ie, the polishing composition 4A. The rate of copper removal first increased and then decreased with increasing BTA concentration.

[Example 5] This example evaluates the synergistic effect between iodate and nitrogen-containing compounds, such as BTA, to improve the rate of removal of tantalum.

A similar substrate containing a tantalum blanket layer was polished with six different polishing compositions (polishing compositions 5A, 5B, 5C, 5D, 5E and 5F). The polishing composition 5A (comparative) contains 0.5 wt% polycondensation silica (80 nm in diameter) and 0.05 wt% KIO.₃Was contained in water at pH 2.4. The polishing composition 5B (invention) contains 0.1 wt% BTA, 0.5 wt% polycondensation silica (diameter 80 nm), and 0.05 wt% KIO.₃Was contained in water at pH 2.4. The polishing composition 5C (comparison) contains 12 wt% polycondensation silica (diameter 25 nm) and 1 wt% H.₂O₂And 40 ppm calcium acetate were contained at pH 9. The polishing composition 5D (comparison) contains 0.1 wt% BTA, 12 wt% polycondensation silica (diameter 25 nm), and 1 wt% H.₂O₂And 40 ppm calcium acetate were contained at pH 9. The results of the removal rate of tantalum are shown in Table 5.

<tables num="5"></tables>

As is clear from the results of the removal rate of tantalum shown in Table 5, the polishing composition 5B containing iodate and BTA is the same as the polishing composition 5A containing a small amount of iodate but not containing BTA. It showed a relatively high removal rate of tantalum. H₂O₂The polishing compositions containing alone or with BTA but not containing iodate, ie, the polishing compositions 5C and 5D, did not show a synergistic effect with BTA in increasing the rate of removal of tantalum.

[Example 6] This example evaluates the effectiveness of various nitrogen-containing compounds in the compositions of the present invention.

16 different polishing compositions (polishing compositions 6A, 6B, 6C, 6D, 6E, 6F, 6G, 6H, 6I, 6J, 6K, 6L, 6M, 6N, 6O and 6P). Each polishing composition is 0.1 wt% KIO₃And 0.5 wt% polycondensation silica (diameter 80 nm) was contained in water at pH 2.6. The polishing composition 6A does not contain BTA, the polishing composition 6B contains 0.1 wt% BTA, and the polishing composition 6C contains 0.01 wt% 1H-1,2,3-benzotriazole-. The polishing composition 6D contains 0.1 wt% 1,2,4-triazole, the polishing composition 6E contains 0.1 wt% pyrazole, and the polishing composition 6F contains 0, containing 5-carboxylic acid. .1 wt% 2-pyrazinecarboxylic acid, polishing composition 6G containing 0.1 wt% 4-pyridyl acetate hydrochloride, polishing composition 6H containing 0.1 wt% 4-amino-1,2 , 4-Triazole, polishing composition 6I containing 3,5-diamino-1,2,4-triazole, polishing composition 6J containing 0.1 wt% 2,6-pyridinecarboxylic acid. The polishing composition 6K contained 0.1 wt% 5-methyl-1H-benzotriazole, and the polishing composition 6L contained 0.002 wt% 3-amino-1,2,4-triazole-5-carboxylic acid. The polishing composition 6M contained 0.02 wt% of 1H-1,2,3-benzotriazole-5-carboxylic acid, and the polishing composition 6N contained 0.02 wt% of 1H-1,2,3-. It contained triazolo [4,5b] pyridine, the polishing composition 6O contained 0.1 wt% methylamine, and the polishing composition 6P contained 0.1 wt% trimethylamine. The results of the removal rates of tantalum, copper and TEOS are shown in Table 6.

<tables num="6"></tables>

As is clear from the results shown in Table 6, all nitrogen-containing compounds except 3,5-diamino-1,2,4-triazole showed high tantalum removal rates along with iodate.

[Example 7] This example evaluates the effectiveness of various abrasives in the compositions of the present invention.

Similar substrates, including tantalum, copper and TEOS blanket layers, were polished with six different polishing compositions (polishing compositions 7A, 7B, 7C, 7D, 7E and 7F). Each polishing composition 7A has a 0.2 wt% KIO.₃And 1 wt% polycondensation silica (diameter 25 nm) was contained in water at pH 2.2. Each polishing composition 7B has a 0.05 wt% KIO.₃And 0.5 wt% polycondensation silica (diameter 80 nm) was contained in water at pH 2.4. Each polishing composition 7C has a 0.2 wt% KIO.₃And 0.5 wt% fumed silica were contained in water at pH 2.2. Each polishing composition 7D has a 0.2 wt% KIO.₃And 0.5 wt% fumed alumina were contained in water at pH 2.2. Each polishing composition 7E has a 0.2 wt% KIO.₃And 0.5 wt% α-alumina was contained in water at pH 2.2. Each polishing composition 7F has 1 wt% KIO.₃And 1 wt% ceria were contained in water at pH 2.1. The results of the removal rates of tantalum, copper and TEOS are shown in Table 7.

<tables num="7"></tables>

As is clear from the removal rate of tantalum shown in Table 7, KIO₃High tantalum removal rate was exhibited by using polycondensation silica in the polishing composition containing.

<figref num="1">It is a graph of the selectivity of Ta / TEOS as a function of the abrasive concentration.</figref>