KR20070035513A - Electrochemical-mechanical polishing composition and method for using the same - Google Patents

Abstract

The present invention provides an electrochemical-mechanical polishing composition comprising (a) a chemically inert water soluble salt, (b) a corrosion inhibitor, (c) a polyelectrolyte, (d) a complexing agent, (e) an alcohol, and (f) water. To provide. The present invention also provides a process comprising (a) providing a substrate comprising at least one conductive metal layer, (b) (i) a chemically inert water soluble salt, (ii) a corrosion inhibitor, (iii) a polyelectrolyte, (iv) complexing Immersing a portion of the substrate in an electrochemical-mechanical polishing composition comprising (v) alcohol, and (vi) water, (c) applying an anode voltage to at least a portion of the substrate immersed in the polishing composition, And (d) grinding at least a portion of the immersed portion of the substrate to polish the substrate.

Electrochemical-mechanical polishing compositions, methods of polishing substrates, chemically inert water soluble salts, anode voltage

Description

Electrochemical-mechanical polishing compositions and methods of use thereof {ELECTROCHEMICAL-MECHANICAL POLISHING COMPOSITION AND METHOD FOR USING THE SAME}

The present invention relates to an electrochemical-mechanical polishing composition and a method of use thereof in electrochemical-mechanical polishing of a substrate comprising at least one conductive metal layer.

In the fabrication of integrated circuits and other electronic devices, multilayer conductor, semiconductor and dielectric materials are deposited on or removed from the substrate surface. Thin layers of conductors, semiconductors and dielectric materials may be deposited on the substrate surface by a number of deposition techniques. Typical deposition techniques for modern microelectronics processing include physical vapor deposition (PVD, also known as sputtering), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), and electrochemical plating (ECP).

As the material layer is subsequently deposited on the substrate and removed from the substrate, the top surface of the substrate may become unflattened and planarization may be required. Surface planarization or "polishing" of a surface is a process that removes material from the surface of a substrate to form a generally uniform and flat surface. Planarization is useful for removing undesirable surface structures and surface defects such as rough surfaces, aggregated materials, crystal lattice damage, scratches and contaminated layers or materials. Planarization is also useful for forming features on the substrate by removing excess deposition material used to fill the features and provide a uniform surface for subsequent levels of metallization and processing.

Chemical-mechanical planarization or chemical-mechanical polishing (CMP) is a common technique used to planarize a substrate. CMP utilizes chemical compositions, typically slurries or other fluid media, to selectively remove material from the substrate. In conventional CMP technology, a substrate carrier or polishing head is installed on the carrier assembly and positioned to contact the polishing pad in the CMP apparatus. The carrier assembly provides controllable pressure to the substrate to allow the substrate to adhere to the polishing pad. The pad is moved along the substrate by an external driving force. The relative movement of the pad and the substrate allows the substrate to be ground by grinding the surface of the substrate to remove some of the material from the substrate surface. Polishing of the substrate by relative movement of the pad and the substrate is typically further facilitated by the chemical activity of the polishing composition and / or the mechanical activity of the abrasive suspended in the polishing composition.

Copper is increasingly used in integrated circuit fabrication due to its desirable electrical properties. However, the use of copper has its own special manufacturing problems. For example, controlled dry etching of copper in ultra wideband integrated (ULSI) applications is very expensive, and technically challenging, using new processes and techniques such as damascene or dual damascene processes. Form copper substrate features. In the damascene process, the features are formed in the dielectric material and subsequently filled with a conductive material (eg copper).

Coupling or “crosstalk between features (eg, between features) to ensure sufficient isolation or separation of different features from relatively small integrated circuits (eg, less than 0.25 micrometers or less than 0.1 micrometers). Dielectric material having a low dielectric constant (eg, less than 3) is used in the manufacture of the damascene structure. However, low k dielectric materials, such as carbon doped silicon oxide, can degrade or break under conventional polishing pressures (eg, 40 kPa) ("downforce"), and such degradation or breakage results in substrate polishing quality and apparatus. May adversely affect formation and / or function. For example, relative rotational movements between the substrate and the polishing pad under conventional CMP downforce can reduce shear forces along the substrate surface, deteriorate low k materials and cause structural defects, which can negatively affect subsequent polishing. have.

One solution for polishing conductive materials (eg copper) in low dielectric materials to reduce or minimize defects is to polish the conductive materials using electrochemical-mechanical polishing (ECMP) techniques. ECMP technology removes conductive material from the substrate surface by electrochemical dissolution while simultaneously polishing the substrate with reduced mechanical grinding compared to conventional CMP processes. Electrochemical dissolution is performed by applying an electrical voltage or bias between the cathode and the substrate surface to remove conductive material from the substrate surface with the surrounding electrolyte or electrochemical-mechanical polishing composition.

While some formulations proposed for electrolyte or electrochemical-mechanical polishing compositions may exist in the art, few of these electrolytes or electrochemical-mechanical polishing compositions exhibit desirable polishing properties. For example, the proposed electrolytic or electrochemical-mechanical polishing composition may exhibit a polishing rate comparable to conventional CMP processes without the need for excessive downforce application, although such electrolytes or electrochemical-mechanical polishing compositions are conductive. Excessive dishing of the material may occur, causing erosion of the dielectric material. Structural defects due to dishing and erosion may further lead to non-uniform removal of another material, such as a barrier layer material deposited below the conductive material and / or dielectric material, from the substrate surface, resulting in less than desired substrates. Creating a surface can negatively affect the performance of the integrated circuit.

Accordingly, there is a need for electrochemical-mechanical polishing compositions and methods using the same which exhibit relatively fast removal rates of substrate material even at low downforces while minimizing dishing and erosion of the substrate. The present invention provides such electrochemical-mechanical polishing compositions and methods of use thereof. These and other advantages and further features of the present invention will become apparent from the description of the invention which follows.

<Overview of invention>

The present invention provides an electrochemical-mechanical polishing composition comprising (a) a chemically inert water soluble salt, (b) a corrosion inhibitor, (c) a polyelectrolyte, (d) a complexing agent, (e) an alcohol, and (f) water. To provide.

The present invention also provides a process comprising (a) providing a substrate comprising at least one conductive metal layer, (b) (i) a chemically inert water soluble salt, (ii) a corrosion inhibitor, (iii) a polyelectrolyte, (iv) complexing Immersing a portion of the substrate in an electrochemical-mechanical polishing composition comprising (v) alcohol, and (vi) water, (c) applying an anode voltage to at least a portion of the substrate immersed in the polishing composition, And (d) grinding at least a portion of the immersed portion of the substrate to polish the substrate.

The present invention provides an electrochemical-mechanical polishing composition comprising (a) a chemically inert water soluble salt, (b) a corrosion inhibitor, (c) a polyelectrolyte, (d) a complexing agent, (e) an alcohol, and (f) water. To provide.

The electrochemical-mechanical polishing composition of the present invention may comprise any suitable chemically inert water soluble salt. As used herein, the term “chemically inert” refers to salts that do not react appreciably chemically with other components present in the electrochemical-mechanical polishing composition. Preferably, the chemically inert water soluble salt does not cause any chemical reaction with other components present in the electrochemical-mechanical polishing composition. The term "water-soluble" as used herein is sufficient to reduce the electrical resistance of the electrochemical-mechanical polishing composition to a level suitable for electrochemical-mechanical polishing (eg, 100 Ω or less, 50 Ω or less, 20 Ω or less, or 1 Ω). Hereinafter) refers to salts that are soluble in water at conventional electrochemical-mechanical polishing temperatures (eg, 25 ° C.). The chemically inert water soluble salt may be any suitable salt having the properties described above. Preferably, the chemically inert water soluble salt is selected from the group consisting of chlorides, phosphates, sulfates and mixtures thereof. More preferably, the chemically inert water soluble salt is potassium sulfate.

Chemically inert water soluble salts may be present in any suitable amount in the electrochemical-mechanical polishing composition. Generally, chemically inert water-soluble salts reduce the electrical resistance of the electrochemical-mechanical polishing composition to a level suitable for electrochemical-mechanical polishing (eg, 100 Ω or less, 50 Ω or less, 20 Ω or less, or 1 Ω or less). Present in the electrochemical-mechanical polishing composition in an amount sufficient for. Preferably, the chemically inert water soluble salt is present in the electrochemical-mechanical polishing composition in an amount of at least 0.1% by weight, more preferably at least 0.5% by weight, based on the total weight of the polishing composition. Preferably, the chemically inert water-soluble salt is 20% by weight or less, more preferably 15% by weight or less, even more preferably 10% by weight or less, most preferably 4% by weight, based on the total weight of the polishing composition. It is present in the electrochemical-mechanical polishing composition in the following amounts.

The electrochemical-mechanical polishing composition of the present invention may comprise any suitable corrosion inhibitor. Typically, corrosion inhibitors are organic compounds containing heteroatom containing functional groups. For example, film formers are heterocyclic organic compounds, such as azole compounds, having at least one 5- or 6-membered heterocyclic ring containing at least one nitrogen atom as the active functional group. Preferably, the corrosion inhibitor is selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, benzotriazole, benzimidazole, benzothiazole and mixtures thereof. Most preferably, the corrosion inhibitor is benzotriazole. The electrochemical-mechanical polishing composition of the present invention may comprise any suitable amount of corrosion inhibitor. Typically, the corrosion inhibitor is present in the electrochemical-mechanical polishing composition in an amount of 0.0001% to 3% by weight, preferably 0.001% to 2% by weight, based on the total weight of the polishing composition.

The electrochemical-mechanical polishing composition of the present invention may comprise any suitable polyelectrolyte. Preferably, the electrochemical-mechanical polishing composition comprises gum arabic, guar gum, hydroxypropyl cellulose, poly (acrylic acid), poly (acrylic acid-co-acrylamide), poly (acrylic acid-co-2,5-furandione) , Poly (acrylic acid-co-acrylamidomethylpropylsulfonic acid), poly (acrylic acid-co-methyl methacrylate-co-4-[(2-methyl-2-propenyl) oxy] -benzenesulfonic acid-co-2 -Methyl-2-propene-1-sulfonic acid), poly (acrylamide), poly (N-sulfopropyl acrylamide), poly (2-acrylamido-2-methylpropane sulfonic acid), poly (diallyl dimethyl ammonium Chloride), poly (ethylene glycol), poly (ethylene imine) (eg linear poly (ethylene imine), poly (methacrylic acid), poly (ethyl methacrylate), poly (sodium methacrylate), poly (sulfo Propyl methacrylate), poly (maleic acid), poly (maleic acid-co-olefin), poly (vinyl alcohol), poly (anilinesulfonic acid), poly (Ethenesulfonic acid), poly (styrenesulfonate), poly (styrene-co-maleic acid), poly (sodium 4-styrenesulfonate), poly (vinylsulfonate), poly (vinyl pyridine), poly (sodium vinyl sulfonate) Pate), poly (ethenesulfonic acid), succinylated poly-L-lysine, poly [aniline-co-N- (3-sulfopropyl) aniline], sodium alginate, xanthan gum and mixtures thereof Most preferably, the polyelectrolyte is poly (acrylic acid) The polyelectrolyte may be present in any suitable amount in the electrochemical-mechanical polishing composition Typically, the polyelectrolyte is based on the total weight of the polishing composition. It is present in the electrochemical-mechanical polishing composition in an amount of at least 0.01% by weight, preferably at least 0.05% by weight, more preferably at least 0.1% by weight and most preferably at least 0.5% by weight. It is present in the electrochemical-mechanical polishing composition in an amount up to 20% by weight, preferably up to 15% by weight, more preferably up to 10% by weight, most preferably up to 5% by weight, based on the total weight of the composition.

During conventional chemical-mechanical polishing processes, complexing agents are typically used to increase the removal rate of the substrate layer to be removed. The electrochemical bias applied to the substrate and polishing composition during the electrochemical-mechanical polishing process may provide a removal rate that is comparable to or greater than that achieved using complexing agents in conventional chemical-mechanical polishing processes. Effective controllability of substrate layer removal (eg removal rate and uniformity of removal) possible in a mechanical polishing process becomes important. In such situations (ie in electrochemical-mechanical polishing processes), the use of complexing agents may improve the uniformity of such removal while improving control of the removal rate due to the electrochemical bias applied to the substrate and polishing composition. I learned that you can. Thus, the electrochemical-mechanical polishing composition of the present invention may comprise any suitable complexing agent. Complexing agents are any suitable chemical additives that bind metals (eg, copper) in solution and can improve the removal rate of the substrate layer to be removed.

Suitable chelating agents or complexing agents include monofunctional organic acids, difunctional organic acids, trifunctional organic acids, polyfunctional organic acids (eg citric acid), inorganic acids (eg phosphoric acid, pyrophosphoric acid, nitric acid), aromatic organic acids, polar organic acids (eg lactic acid, Methyl lactic acid, tartaric acid, malic acid), unsaturated organic acids, amino acids, aromatic amino acids (such as anthranilic acid, picolinic acid, hydroxypicolinic acid), morpholino compounds, and zwitterionic compounds (such as betaine). . More specifically, suitable chelating agents or complexing agents include, for example, carbonyl compounds (eg, acetylacetonate, etc.), simple carboxylates (eg, acetate, aryl carboxylates, etc.), one or more hydroxyl groups. Carboxylates (eg, glycolates, lactates, gluconates, gallic acids and salts thereof), di-, tri- and poly-carboxylates (eg oxalates, phthalates, citrate, succinates) Tartrate, maleate, edetate (such as dipotassium EDTA), mixtures thereof, and the like, and carboxylates containing one or more sulfone and / or phosphone groups. Suitable chelating agents or complexing agents include, for example, di-, tri- or polyalcohols (eg ethylene glycol, pyrocatechol, pyrogallol, tannic acid, etc.) and amine-containing compounds (eg ammonia, amino acids). And amino alcohols, di-, tri- and polyamines). The choice of suitable chelating agent or complexing agent will depend on the type of substrate layer to be polished (eg the type of metal). Preferably, the complexing agent is selected from the group consisting of carboxylic acids, di-carboxylic acids, tri-carboxylic acids, polycarboxylic acids and mixtures thereof. More preferably, the complexing agent is lactic acid, tartaric acid, citric acid, malonic acid, phthalic acid, succinic acid, glycolic acid, propionic acid, acetic acid, salicylic acid, picolinic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 2-methyl lactic acid , Salts thereof, and mixtures thereof, most preferably the complexing agent is lactic acid. Most of the compounds mentioned above may be present in the form of salts (eg metal salts, ammonium salts, etc.), acids or partial salts. For example, citrate includes not only citric acid but also monovalent, divalent and trivalent salts thereof.

The complexing agent may be present in any suitable amount in the electrochemical-mechanical polishing composition. Typically, the complexing agent is electrochemical-mechanical in an amount of at least 0.01 wt%, preferably at least 0.05 wt%, more preferably at least 0.1 wt%, most preferably at least 0.5 wt%, based on the total weight of the polishing composition. Present in the polishing composition. Complexing agents are typically present in the electrochemical-mechanical polishing composition in amounts of up to 10% by weight, preferably up to 5% by weight, based on the total weight of the polishing composition.

As described above, the electrochemical-mechanical polishing composition of the present invention comprises an alcohol. The electrochemical-mechanical polishing composition may comprise any suitable alcohol. Preferably, the alcohol is methanol, ethanol, propanol (eg 1-propanol or 2-propanol), butanol (eg 1-butanol, 2-butanol or tert-butanol (ie 2-methylpropan-2-ol) ) And mixtures thereof. More preferably, the alcohol comprises propanol (eg 2-propanol or isopropyl alcohol). Alternatively, the alcohol can be a branched or linear alcohol with a higher molecular weight than butanol.

The alcohol may be present in any suitable amount in the electrochemical-mechanical polishing composition, but is typically present in the electrochemical-mechanical polishing composition in an amount of at least 5% by weight based on the total weight of the polishing composition. Preferably, the alcohol is present in the electrochemical-mechanical polishing composition in an amount of at least 10% by weight, more preferably at least 15% by weight, based on the total weight of the polishing composition. Typically, the alcohol is at most 40%, preferably at most 35%, more preferably at most 30%, even more preferably at most 25%, most preferably 20, based on the total weight of the polishing composition. Present in the electrochemical-mechanical polishing composition in an amount up to percent by weight.

In the electrochemical-mechanical polishing composition of the present invention, it dissolves chemically inert water soluble salts and promotes the application of corrosion inhibitors, polyelectrolytes, complexing agents, alcohols and any other additives to the surface of a suitable substrate to be polished or planarized. To use a liquid carrier. As described above, the liquid carrier is preferably water (eg deionized water). The liquid carrier may further comprise a suitable water miscible solvent. However, in certain preferred embodiments, the liquid carrier consists essentially of water, more preferably deionized water, or consists of water, more preferably deionized water.

The electrochemical-mechanical polishing composition can have any suitable pH. Typically, the pH of the electrochemical-mechanical polishing composition is 13 or less. Preferably, the pH of the electrochemical-mechanical polishing composition is 7 or less (eg 6 or less, 5 or less or 4 or less). Typically, the pH of the electrochemical-mechanical polishing composition is at least 1 (eg, at least 2).

The pH of the electrochemical-mechanical polishing composition can be achieved and / or maintained by any suitable means. More specifically, the polishing composition may further comprise a pH adjuster, a pH buffer or a combination thereof. The pH adjusting agent can be any suitable pH-adjusting compound. For example, the pH adjusting agent may be potassium hydroxide, sodium hydroxide, ammonium hydroxide or a combination thereof. The pH buffer may be any suitable buffer such as phosphate, acetate, borate, ammonium salts and the like. The electrochemical-mechanical polishing composition may comprise any suitable amount of pH adjuster and / or pH buffer, provided that such amount is sufficient to achieve and / or maintain the pH of the polishing composition within the ranges described above.

The electrochemical-mechanical polishing composition optionally further comprises a surfactant. Suitable surfactants include, for example, cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, mixtures thereof, and the like. Preferably, the polishing composition comprises a nonionic surfactant. One example of a suitable nonionic surfactant is an ethylenediamine polyoxyethylene surfactant. The amount of surfactant is typically from 0.0001% to 1% by weight (preferably 0.001% to 0.1%, or 0.005% to 0.05% by weight) based on the weight of the liquid carrier and any components dissolved or suspended therein. )to be.

The electrochemical-mechanical polishing composition optionally further comprises an antifoaming agent. Defoamers can be any suitable defoamer. Suitable antifoams include, but are not limited to, silicone based and acetylenic diol based antifoams. The amount of antifoam agent present in the polishing composition is typically 40 ppm to 140 ppm.

The electrochemical-mechanical polishing composition optionally further comprises a biocide. The biocide can be any suitable biocide such as isothiazolinone biocide. The amount of biocide used in the polishing composition is usually 1 to 50 ppm, preferably 10 to 20 ppm.

The electrochemical-mechanical polishing composition of the present invention may be prepared by any suitable method, as those skilled in the art will understand. Typically, the electrochemical-mechanical polishing composition is prepared in any suitable order by adding chemically inert water soluble salts, corrosion inhibitors, polyelectrolytes, complexing agents, alcohols and any other additives to water. In order to ensure the homogeneity of the resulting electrochemical-mechanical polishing composition, water is preferably stirred for a suitable time while the components are added to water and / or the components of the polishing composition are added to water. When used in combination with the substrate polishing method, the electrochemical-mechanical polishing composition of the present invention may be used at any suitable time after its preparation. Preferably, the electrochemical-mechanical polishing composition of the present invention is used within 30 days, more preferably within 10 days (eg, within 240 hours) from the preparation of the electrochemical-mechanical polishing composition.

Alternatively, the electrochemical-mechanical polishing composition of the present invention may be prepared by mixing the components of the polishing composition at or near the point of use. As used herein, the term "point of use" refers to the point where an electrochemical-mechanical polishing composition is applied to a substrate surface (eg, polishing pad or substrate surface itself). When the electrochemical-mechanical polishing composition is prepared using mixing at the point of use, the components of the electrochemical-mechanical polishing composition are stored separately in two or more storage devices. As used herein, the term "component" of an electrochemical-mechanical polishing composition refers to any single compound or component of the polishing composition (eg, chemically inert water soluble salts, corrosion inhibitors, polyelectrolytes, complexing agents, alcohols, any other Additives or water), or any combination of one or more such compounds or components (eg, corrosion inhibitors, alcohols and optionally at least a portion of water).

In order to mix the components contained in the storage device to prepare the electrochemical-mechanical polishing composition at or near the point of use, the storage device typically has one or more flow lines connected from each storage device to the point of use of the polishing slurry. (Eg, platen, polishing pad or substrate surface) is provided. The term "flow line" means the flow path from each storage vessel to the point of use of the components stored there. One or more flow lines may each be directly connected to a point of use, or if more than one flow line is used, two or more flow lines may be combined with a single flow line connected to a point of use at any point. In addition, any one or more flow lines (eg, each flow line or combined flow line) are first connected to one or more other devices (eg, pumping devices, metering devices, mixing devices, etc.) and then the component (s) The point of use can be reached.

The components of the electrochemical-mechanical polishing composition can be delivered individually to the point of use (eg, the components are delivered to the substrate surface, where the components are mixed during the polishing process), or the components are delivered to the point of use. May be combined immediately before. Less than 10 seconds before the component reaches the point of use, preferably less than 5 seconds before reaching the point of use, more preferably less than 1 second before reaching the point of use, or even to the point of use of the component When formulated concurrently with delivery, the components are formulated “just prior to delivery to the point of use” (eg, the components are formulated in a dispenser). In addition, when components are formulated within 5 m of the point of use, such as within 1 m of the point of use or even within 10 cm of the point of use (eg, within 1 cm of the point of use), the components are delivered to the “point of use. Just before it is formulated.

If two or more components are formulated before reaching the point of use, the components can be formulated in a flow line and delivered to the point of use without using a mixing device. Alternatively, one or more flow lines can be connected to the mixing device to facilitate the combination of two or more components. Any suitable mixing device can be used. For example, the mixing device may be a nozzle or jet (eg, a high pressure nozzle or jet) through which two or more components flow and pass. Alternatively, the mixing device may comprise one or more inlets through which two or more components of the polishing slurry are introduced into the mixer, and the mixing components are discharged from the mixer and directly to the point of use or through another member of the apparatus (eg, one or more flow lines). Through) one or more outlets to be delivered. The mixing device may also include one or more chambers, each chamber having one or more inlets and one or more outlets, wherein two or more components are combined in each chamber. When using a container type mixing device, the mixing device preferably comprises a mixing mechanism for further promoting the blending of the components. Mixing mechanisms are generally known in the art and include stirrers, blenders, shakers, paddled baffles, gas sparger systems, vibrators and the like.

The electrochemical-mechanical polishing composition of the present invention may also be provided as a concentrate which is diluted with an appropriate amount of water before use. In such embodiments, the electrochemical-mechanical polishing composition concentrate is electrochemically prepared by diluting the chemically inert water-soluble salts, corrosion inhibitors, polyelectrolytes, complexing agents, alcohols and other optional additives with the appropriate amount of water. -Each component of the mechanical polishing composition may be included in an amount such that it is present in the polishing composition in an amount within the appropriate ranges described above for each component. For example, chemically inert water soluble salts, corrosion inhibitors, polyelectrolytes, complexing agents and alcohols may be present in amounts greater than two (eg, three, four or five times) the concentrations described above for each component. By being present in concentration, when the concentrate is diluted with an equivalent amount of water (e.g., twice the equivalent amount of water, three times the equivalent amount of water, or four times the equivalent amount of water), each component is described above for each component. It may be present in the electrochemical-mechanical polishing composition in an amount within the range. In addition, as will be appreciated by those skilled in the art, the concentrate may be formulated with a final electrochemical-mechanical polishing composition to ensure that the chemically inert water-soluble salts, polyelectrolytes, complexing agents and other suitable additives are at least partially or completely dissolved in the concentrate. It may contain a suitable water fraction present in the.

The present invention also provides a method of polishing a substrate using the electrochemical-mechanical polishing composition described above. The method for polishing a substrate according to the invention generally comprises the steps of (a) providing a substrate, (b) immersing a portion of the substrate in the electrochemical-mechanical polishing composition of the invention, and (c) applying an anode voltage to the substrate. And (d) grinding at least a portion of the submerged portion of the substrate to polish the substrate.

More specifically, the present invention provides a process for preparing a substrate comprising (a) providing a substrate comprising at least one conductive metal layer, (b) (i) a chemically inert water soluble salt, (ii) a corrosion inhibitor, (iii) a polyelectrolyte, (iv) immersing a portion of the substrate in an electrochemical-mechanical polishing composition comprising a complexing agent, (v) alcohol, and (vi) water, and (c) applying an anode voltage to at least a portion of the substrate immersed in the polishing composition. A method of polishing a substrate comprising at least one conductive metal layer, comprising applying and polishing (d) at least a portion of the immersed portion of the substrate to polish the substrate.

The method of the present invention can be used to polish any suitable substrate. For example, the electrochemical-mechanical polishing compositions and methods of the present invention can be used in microelectronic substrates (eg, integrated circuits, memory or rigid disks, metals, ILD layers, semiconductors, thin films, microelectromechanical systems, ferroelectrics, magnetic heads, Polymer film, and low or high dielectric film). The substrate may comprise any suitable insulator, metal or alloy layer (eg, conductive metal layer). The insulation layer may be a metal oxide, porous metal oxide, glass, organic polymer, fluorinated organic polymer or any other suitable high or low-k insulation layer. The metal layer may be any suitable metal, including a metal selected from the group consisting of copper, tungsten, aluminum (eg, at pH 11 or higher), titanium, platinum, rhodium, iridium, silver, gold, nickel, ruthenium, and mixtures thereof. It may include. In general, substrates that can be suitably polished using the electrochemical-mechanical polishing compositions and methods of the present invention include one or more conductive metal layers. Preferably, the conductive metal layer comprises copper.

The anode voltage can be applied to the substrate by any suitable means. Typically, the apparatus used to carry out the method is one that is immersed in an electrochemical-mechanical polishing composition and the other is coupled to the substrate via, for example, a conductive polishing pad and / or a platen of the polishing apparatus. At least two electrodes. In this arrangement, the electrode is typically connected to a power source, and an electrical voltage or bias is applied to the electrode so that an anode (positive) voltage is applied to the substrate. The power supply is regulated to supply a constant current or a constant voltage to the electrodes and the substrate. In certain embodiments, a constant current may be applied to the electrode and / or the substrate for a predetermined first time, and then a constant voltage may be applied to the electrode and / or the substrate for the predetermined second time. In such embodiments, applying a constant current and a constant voltage to the substrate may be performed in any suitable order. The electrical voltage applied to the electrode and / or the substrate can vary constantly or over time (ie, time-varying voltage).

The immersed portion of the substrate may be ground by any suitable means to polish the substrate. Generally, the substrate is typically ground using a polishing pad connected with the polishing platen of the electrochemical-mechanical polishing apparatus. If a polishing pad is present, it may be any suitable abrasive or non-abrasive polishing pad.

In certain embodiments, the methods of the present invention may include an additional step of performing before or after polishing at least a portion of the substrate through applying an anode voltage to the immersed substrate. In particular, the method of the present invention may further comprise polishing the substrate using the chemical-mechanical polishing composition. Typically, the additional steps mentioned above are performed after the substrate has been polished through applying the anode voltage to at least a portion of the substrate immersed in the polishing composition of the present invention (ie, step (d) above), and also the anode It can be done without applying a voltage to the substrate. The chemical-mechanical polishing composition used in this additional step preferably comprises an oxidizing agent. The oxidant can be any suitable oxidant. Preferably, the oxidant is a peroxide (eg hydrogen peroxide). In certain embodiments, the electrochemical-mechanical polishing composition of the present invention may further comprise an oxidizing agent so that, in the additional steps mentioned above, the electrochemical-mechanical polishing composition may also be used as the chemical-mechanical polishing composition.

The method of polishing a substrate according to the invention can be carried out in any suitable apparatus. Suitable electrochemical-mechanical polishing apparatuses include U.S. Patent No. 6,379,223, U.S. Patent Application Publication Nos. 2002/0111121 A1, 2002/0119286 A1, 2002/0130049 A1, 2003/0010648 A1, Devices disclosed in WO 2003/0116445 A1, and WO 2003/0116446 A1, and International Patent Application WO 03/001581 A2.

Claims (30)

(a) chemically inert water-soluble salts, (b) corrosion inhibitors, (c) polyelectrolytes, (d) complexing agents, (e) alcohols present in the polishing composition in an amount of at least 5% by weight based on the total weight of the polishing composition, and (f) water Electrochemical-mechanical polishing composition comprising a. The polishing composition according to claim 1, wherein the chemically inert water-soluble salt is potassium sulfate, the corrosion inhibitor is benzotriazole, the polyelectrolyte is poly (acrylic acid), the complexing agent is lactic acid, and the alcohol is propanol. The chemically inert water-soluble salt is present in the polishing composition in an amount of 0.5 to 4 weight percent based on the total weight of the polishing composition, and alcohol is 15 to 20 weight percent based on the total weight of the polishing composition. A polishing composition present in the polishing composition in an amount of. The polishing composition of claim 1, wherein the chemically inert water soluble salt is present in the polishing composition in an amount of 0.5 to 10 weight percent based on the total weight of the polishing composition. The polishing composition of claim 1 wherein the pH is 7 or less. The method of claim 1, (a) a chemically inert water-soluble salt selected from the group consisting of chlorides, phosphates, sulfates and mixtures thereof, (b) a corrosion inhibitor selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, benzotriazole, benzimidazole, benzothiazole and mixtures thereof, (c) gum arabic, guar gum, hydroxypropyl cellulose, poly (acrylic acid), poly (acrylic acid-co-acrylamide), poly (acrylic acid-co-2,5-furandione), poly (acrylic acid-co-acrylic Amidomethylpropylsulfonic acid), poly (acrylic acid-co-methyl methacrylate-co-4-[(2-methyl-2-propenyl) oxy] -benzenesulfonic acid-co-2-methyl-2-propene- 1-sulfonic acid), poly (acrylamide), poly (N-sulfopropyl acrylamide), poly (2-acrylamido-2-methylpropane sulfonic acid), poly (diallyl dimethyl ammonium chloride), poly (ethylene glycol) , Poly (ethylene imine), poly (methacrylic acid), poly (ethyl methacrylate), poly (sodium methacrylate), poly (sulfopropyl methacrylate), poly (maleic acid), poly (maleic acid- Co-olefin), poly (vinyl alcohol), poly (aniline sulfonic acid), poly (ethenesulfonic acid), poly (styrenesulfonate), poly (styrene-co-maleic acid), poly (nat 4-styrenesulfonate), poly (vinylsulfonate), poly (vinyl pyridine), poly (sodium vinyl sulfate), poly (ethenesulfonic acid), succinylated poly-L-lysine, poly [aniline-co-N -(3-sulfopropyl) aniline], sodium alginate, xanthan gum and mixtures thereof; (d) a complexing agent selected from the group consisting of carboxylic acids, di-carboxylic acids, tri-carboxylic acids, polycarboxylic acids and mixtures thereof, (e) alcohols present in the polishing composition in an amount of at least 5% by weight based on the total weight of the polishing composition, selected from the group consisting of methanol, ethanol, propanol, butanol and mixtures thereof, and (f) water Polishing composition comprising a. The polishing composition of claim 6, wherein the chemically inert water soluble salt is present in the polishing composition in an amount of 0.5 to 10 weight percent based on the total weight of the polishing composition. 7. The polishing composition of claim 6 wherein the corrosion inhibitor is benzotriazole. 7. The polishing composition of claim 6 wherein the polyelectrolyte is poly (acrylic acid). The complexing agent of claim 6 wherein the complexing agent is lactic acid, tartaric acid, citric acid, malonic acid, phthalic acid, succinic acid, glycolic acid, propionic acid, acetic acid, salicylic acid, picolinic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 2- Polishing composition selected from the group consisting of methyl lactic acid, salts thereof, and mixtures thereof. The polishing composition of claim 10, wherein the complexing agent is lactic acid. 7. The polishing composition of claim 6 wherein the alcohol is propanol. The polishing composition of claim 6, wherein the alcohol is present in an amount of from 15 to 25 weight percent based on the total weight of the polishing composition. The polishing composition according to claim 6, wherein the pH is 7 or less. (a) providing a substrate comprising at least one conductive metal layer, (b) (i) chemically inert water-soluble salts,     (ii) corrosion inhibitors,     (iii) polyelectrolytes,     (iv) complexing agents,     (v) alcohols present in the polishing composition in an amount of at least 5% by weight based on the total weight of the polishing composition, and     (vi) water Immersing a portion of the substrate in an electrochemical-mechanical polishing composition comprising; (c) applying an anode voltage to at least a portion of the substrate immersed in the polishing composition, and (d) grinding the substrate by grinding at least a portion of the submerged portion of the substrate. A polishing method of a substrate comprising at least one conductive metal layer comprising a. The method of claim 15, wherein the conductive metal layer comprises copper. The method of claim 16 wherein the chemically inert water soluble salt is potassium sulfate, the corrosion inhibitor is benzotriazole, the polyelectrolyte is poly (acrylic acid), the complexing agent is lactic acid, and the alcohol is propanol. The chemically inert water-soluble salt of claim 15, wherein the chemically inert water-soluble salt is present in the polishing composition in an amount of 0.5 to 4 weight percent based on the total weight of the polishing composition and alcohol is 15 to 20 weight percent based on the total weight of the polishing composition. Present in the polishing composition in an amount of. The method of claim 15, wherein the chemically inert water soluble salt is present in the polishing composition in an amount of 0.5 to 10 weight percent based on the total weight of the polishing composition. The method of claim 15, wherein the polishing composition has a pH of 7 or less. The method of claim 15, wherein the polishing composition is (i) a chemically inert water-soluble salt selected from the group consisting of chlorides, phosphates, sulfates and mixtures thereof, (ii) a corrosion inhibitor selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, benzotriazole, benzimidazole, benzothiazole and mixtures thereof, (iii) gum arabic, guar gum, hydroxypropyl cellulose, poly (acrylic acid), poly (acrylic acid-co-acrylamide), poly (acrylic acid-co-2,5-furandione), poly (acrylic acid-co-acrylic Amidomethylpropylsulfonic acid), poly (acrylic acid-co-methyl methacrylate-co-4-[(2-methyl-2-propenyl) oxy] -benzenesulfonic acid-co-2-methyl-2-propene- 1-sulfonic acid), poly (acrylamide), poly (N-sulfopropyl acrylamide), poly (2-acrylamido-2-methylpropane sulfonic acid), poly (diallyl dimethyl ammonium chloride), poly (ethylene glycol) , Poly (ethylene imine), poly (methacrylic acid), poly (ethyl methacrylate), poly (sodium methacrylate), poly (sulfopropyl methacrylate), poly (maleic acid), poly (maleic acid- Co-olefin), poly (vinyl alcohol), poly (aniline sulfonic acid), poly (ethenesulfonic acid), poly (styrenesulfonate), poly (styrene-co-maleic acid), poly (I 4-styrenesulfonate), poly (vinylsulfonate), poly (vinyl pyridine), poly (sodium vinyl sulfate), poly (ethenesulfonic acid), succinylated poly-L-lysine, poly [aniline-co-N -(3-sulfopropyl) aniline], sodium alginate, xanthan gum and mixtures thereof; (iv) a complexing agent selected from the group consisting of carboxylic acids, di-carboxylic acids, tri-carboxylic acids, polycarboxylic acids and mixtures thereof, (v) alcohols present in the polishing composition in an amount of at least 5% by weight based on the total weight of the polishing composition, selected from the group consisting of methanol, ethanol, propanol, butanol and mixtures thereof, and (vi) water Method comprising a. The method of claim 21, wherein the conductive metal layer comprises copper. The method of claim 21, wherein the chemically inert water soluble salt is present in the polishing composition in an amount of 0.5 to 10 weight percent based on the total weight of the polishing composition. The method of claim 21 wherein the corrosion inhibitor is benzotriazole. The method of claim 18, wherein the polyelectrolyte is poly (acrylic acid). The complexing agent of claim 21 wherein the complexing agent is lactic acid, tartaric acid, citric acid, malonic acid, phthalic acid, succinic acid, glycolic acid, propionic acid, acetic acid, salicylic acid, picolinic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 2-methyl lactic acid , Salts thereof and mixtures thereof. The method of claim 26, wherein the complexing agent is lactic acid. The method of claim 21, wherein the alcohol is propanol. The method of claim 21, wherein the alcohol is present in the polishing composition in an amount of 15 to 25 weight percent based on the total weight of the polishing composition. The method of claim 21, wherein the polishing composition has a pH of 7 or less.