Modified water-soluble polysaccharides with different cation types for slurries in chemical mechanical planarization

Abstract

The synthesis of a cationically modified water-soluble polysaccharide is disclosed. The cations are pendant to the polysaccharide backbone. A chemical mechanical planarization (CMP) slurry contains an abrasive, an activator, an oxidizer, an additive including the cationically modified water-soluble polysaccharide, and water. The use of the synthetic cationically modified water-soluble polysaccharide in the CMP slurry reduces dishing and erosion in highly selective tungsten slurries.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 377,802, filed September 30, 2022, the entire contents of which are incorporated herein by reference for all permissible purposes. [Background technology]

[0002] This disclosure relates to chemical mechanical planarization (CMP) slurries (or compositions or formulations), polishing methods, and polishing systems for performing chemical mechanical planarization in the manufacture of semiconductor devices. In particular, this disclosure relates to polishing slurries suitable for use in polishing patterned semiconductor wafers that include tungsten-containing metallic materials.

[0003] Chemical mechanical polishing or planarization (CMP) has been used successfully in the manufacturing process of integrated circuits for decades and is considered a key and enabling technology for the demand for miniaturization.

[0004] Integrated circuits are interconnected using well-known multilayer interconnects. The interconnect structure typically includes a first layer of metallization, an interconnect layer, a second layer of metallization, and typically a third and subsequent layers of metallization. To electrically isolate different layers of metallization within a silicon substrate or well, interlayer insulating materials such as silicon dioxide, and sometimes low-k materials, are used. Electrical connections between different interconnect layers are made through the use of metallized vias, particularly tungsten vias. U.S. Pat. No. 4,789,648 describes a method for preparing multiple metallized layers and vias in an insulating film. Similarly, metal contacts are used to form electrical connections between interconnect layers and devices formed within the wells. Metal vias and contacts are typically filled with tungsten, and adhesion layers, such as titanium nitride (TiN) and / or titanium, are typically used to bond the metal layer, such as the tungsten metal layer, to the insulating material.

[0005] In one semiconductor manufacturing process, metallized vias or contacts are formed by blanket tungsten deposition followed by a CMP step. In a typical process, a via hole is etched through an interlevel dielectric (ILD) to an interconnect line or semiconductor substrate. Next, a thin adhesion layer, such as titanium nitride and / or titanium, is typically formed on top of the ILD and directed into the etched via hole. A tungsten film is then blanket deposited on the adhesion layer and into the via. Deposition continues until the via hole is filled with tungsten. Finally, excess tungsten is removed by CMP to form the metal via.

[0006] In another semiconductor manufacturing process, tungsten is used as a gate electrode material for transistors because it has better electrical properties than polysilicon, which has traditionally been used as a gate electrode material, as taught by A. Yagishita et al., IEEE TRANSACTIONS ON ELECTRON DEVICES, VOL. 47, NO. 5, MAY 2000.

[0007] In a typical CMP process, the substrate is placed in direct contact with a rotating polishing pad. A carrier applies pressure against the backside of the substrate. During the polishing process, the pad and table are rotated while a downward force is maintained against the backside of the substrate. An abrasive and chemically reactive solution, commonly referred to as a polishing "slurry," "composition," or "formulation," is deposited on the pad during polishing, and the rotation and / or motion of the pad relative to the wafer transports the slurry into the space between the polishing pad and the substrate surface. The slurry initiates the polishing process by chemically reacting with the film being polished. The polishing process is driven by the rotational motion of the pad relative to the substrate as the slurry is delivered to the wafer / pad interface. Polishing continues in this manner until the desired film on the insulator is removed. It is believed that tungsten removal in CMP is due to a synergistic effect of mechanical polishing and tungsten oxidation and subsequent dissolution.

[0008] Despite its relatively simple appearance, chemical mechanical planarization (CMP) is a highly complex process, as described by Lee Cook in Digital Encyclopedia of Applied Physics, 2019, DOI: 10.1002 / 3527600434.eap847, and in most cases, CMP technology is evolving faster than the understanding it is based on, as described by Seo, J. in Journal of Materials Research 2021, 36(1), 235.1.

[0009] Its importance as an enabling technology for past and future demands of device scaling and new trends in the semiconductor industry is undeniable. The numerous interactions between the wafer, slurry, and pad, as well as overall process parameters, determine the results of CMP. Finally, material removal in CMP is the result of a complex interplay between chemical and mechanical forces, as described in Lee, D.; Lee, H.; Jeong, H. Slurry components in metal chemical mechanical planarization (CMP) process: A review. International Journal of Precision Engineering and Manufacturing 2016, 17, 1751. Numerous materials are used in semiconductor device manufacturing, all of which require an optimized CMP process. Simultaneous polishing of completely different material combinations, such as insulating materials, barrier layers, and metal layers, presents a real challenge for CMP.

[0010] One of the problems commonly encountered in CMP, especially in metal applications such as tungsten, is how to control topological defects such as erosion and dishing. Smaller feature sizes and devices at the 7 nm node and beyond impose even more stringent requirements on defect tolerance during polishing.

[0011] Highly selective slurries have a large differential in metal removal rate versus dielectric removal rate and are of great interest for future industrial needs. However, there are imperfections associated with the use of these highly selective slurries. Metal layers can easily be over-polished, resulting in a "dishing" effect. Another unacceptable defect is called "erosion," which describes the difference in topography between areas with dielectric layers and dense arrays of metal vias or trenches.

[0012] Specially designed aqueous slurries are considered a major driver in improving CMP performance for future devices. Slurry development not only affects the removal rate and selectivity between different layers, but also controls defects during the polishing process. Generally, slurry compositions are complex combinations of abrasives and chemical components with different functions. Polymer additives, such as dispersants, passivators, or generally topography control additives, play an important role in slurry development to achieve the desired removal rate, selectivity, and minimize surface defects by interacting with specific materials. For example, positively charged polymers inhibit tungsten removal and can be used to reduce the dishing effect in tungsten CMP processes.

[0013] U.S. Pat. No. 5,876,490 describes the use of a polishing slurry containing abrasive particles, exhibiting a normal stress effect, and further containing a polyelectrolyte having ionic moieties of a different charge than those associated with the abrasive particles, the polyelectrolyte having a concentration of about 5 to about 50% by weight of the abrasive particles, and the polyelectrolyte having a molecular weight of about 500 to about 10,000.

[0014] U.S. Patent Application Publication No. 2010 / 0075501(A1) describes an aqueous chemical mechanical polishing dispersion used to polish a polishing target including a tungsten-containing interconnect layer. The aqueous chemical mechanical polishing dispersion includes (A) a cationic water-soluble polymer, (B) an iron(III) compound, and (C) colloidal silica particles. The content of (A) the cationic water-soluble polymer (M A ) (mass%) and (B) the content of iron (III) compounds (M B ) (mass%) means "M A / M B =0.004 to 0.1”. The chemical mechanical polishing aqueous dispersion has a pH of 1 to 3.

[0015] U.S. Patent Application Publication No. 2010 / 0252774(A1) describes an aqueous dispersion for chemical mechanical polishing used to polish a polishing target including a wiring layer containing tungsten. The aqueous dispersion for chemical mechanical polishing contains (A) a cationic water-soluble polymer, (B) an iron(III) compound, and (C) colloidal silica having an average particle size of 10 to 60 nm calculated from the specific surface area by the BET method. The content of (A) the cationic water-soluble polymer (M A ) (mass%) and (C) the content of colloidal silica (M C ) (mass%) and "M A / M C =0.0001 to 0.003". Aqueous dispersion for chemical mechanical polishing.

[0016] U.S. Patent No. 10,604,678 (B1) discloses a process and composition for polishing tungsten, which contains a low concentration of a selected quaternary phosphonium compound to at least reduce the corrosion rate of tungsten. The method and composition include providing a tungsten-containing substrate, providing a stable polishing composition containing as initial components water, an oxidizing agent, a selected quaternary phosphonium compound at a low concentration to at least reduce the corrosion rate, a dicarboxylic acid, an iron ion source, a colloidal silica abrasive, and optionally a pH adjuster, providing a chemical mechanical polishing pad having a polishing surface, creating dynamic contact at the interface between the polishing pad and the substrate, and dispensing the polishing composition on the polishing surface at or near the interface between the polishing pad and the substrate, whereby a portion of the tungsten is polished away from the substrate and the corrosion rate of the tungsten is reduced.

[0017] U.S. Patent Application Publication No. 2009 / 0081871(A1) discloses a method comprising chemically mechanically polishing a substrate with an inventive polishing composition comprising a liquid carrier, a cationic polymer, an acid, and abrasive particles treated with an aminosilane compound.

[0018] U.S. Patent Application Publication No. 2014 / 0248823(A1) describes a chemical-mechanical polishing composition containing (a) abrasive particles, (b) a polymer, and (c) water, wherein (i) the polymer has a total charge, (ii) the abrasive particles have a zeta-potential Za measured in the absence of the polymer, and a zeta-potential Zb measured in the presence of the polymer, where Za is a value with the same sign as the total charge of the polymer, and (iii) |Zeta-potential Zb|>|Zeta-potential Za|. The present invention also provides a method for polishing a substrate with the polishing composition.

[0019] Generally, the described polyelectrolytes essentially contain nitrogen-containing cations of the ammonium type. Polyionic liquids based on imidazolium-type phosphonium groups and triazole- or triazolium-based polymers are identified and used in CMP slurries in U.S. Provisional Patent Applications Nos. 63 / 191,047, filed May 20, 2021, 63 / 209,306, filed June 10, 2021, and 63 / 251,127, filed October 1, 2021, respectively, which are incorporated herein by reference in their entireties.

[0020] One of the problems commonly encountered in CMP, especially in metal applications such as tungsten, is dishing of tungsten lines and erosion of metal line arrays. Dishing and erosion are important CMP parameters that define the planarity of the polished wafer. Line dishing typically increases with wider lines. Array erosion typically increases with increasing pattern density.

[0021] Tungsten CMP slurries should be formulated to minimize dishing and erosion to meet specific design goals that are critical to device functionality.

[0022] Finding solutions to control topology defects such as erosion and dishing is important for future CMP requirements. There remains a need for new tungsten CMP slurries that can reduce dishing and erosion while maintaining desirable removal rates during polishing. Summary of the Invention

[0023] The present invention fills this need by providing an intelligently designed tungsten CMP slurry, a system and method for using the CMP slurry, to minimize the noted problems of dishing and erosion in highly selective tungsten slurries while maintaining desirable polishing of metal layers, particularly tungsten films.

[0024] More specifically, the present invention discloses tailored cationically modified water-soluble polysaccharides in which cations are pendant to the water-soluble polysaccharide backbone, their synthesis, and their use in CMP slurries.Various functional groups can be attached to the water-soluble polysaccharide backbone (from bulky groups to less sterically hindered groups) to fine-tune the performance and properties of the polymer.

[0025] Some specific aspects of the invention are outlined below. Embodiment 1: The cationically modified water-soluble polysaccharide comprises a cationic repeat unit having a structure selected from the group consisting of: [ka] During the ceremony, the water-soluble polysaccharide is selected from the group consisting of chitosan, pectin, dextran, pullulan, and inulin; The pentagon or hexagon represents the backbone of the water-soluble polysaccharide; Z is NH, -O-, -S-, -O-(C=O)-, is selected from the group consisting of -NH-(C=O)-, -O-(C=O)-, -NH-(C=O)-, NR' (R' is an alkyl having C1 to C6), and a carbon-carbon double or triple bond as shown below: [ka] The two carbon atoms in the double bond structure can be connected to two protons, or one proton and one alkyl group R'', where R is an alkyl group having C1 to C6, or two identical alkyl groups R'', or two different alkyl groups R and R''', where R is an alkyl group having C1 to C6; Preferably, Z represents NH or —O—, Sp represents, at each occurrence, the presence of a spacer group having a single or double bond structure, preferably a single bond structure; Y + is N + , P + , S + represents a cationic functional group such as X - is a halide (F - , Cl - , Br - , I - ), BF4 - , CF3BF3 - , O.H. - ,PF6 - , carboxylate, malonate, citrate, carbonate, fumarate, MeOSO3 - , MeSO3 - (Me is methyl), CF3COO - , CF3SO3 - represents a counterion which may be cyanate, isothiocyanate, nitrate, phosphate or sulfate; R represents a cationic side group selected from the group consisting of H, CH3, an alkyl chain (saturated or unsaturated, branched or aliphatic), a cyclic ring, such as a phenyl ring, and other functional groups, such as an amine, a carboxylic acid, a sulfonate, a siloxane, an ether, an alcohol, another cation, and other side groups, and (R)3 can be alkyl or can form a ring selected from the group consisting of imidazolium, triazolium, and tetrazolium, tris-alkylphosphonium, tris-phenylphosphonium, tris-alkylsulfonium, and tris-phenylsulfonium. n represents the number of repeating units and 1 < n < 2000, 50 < n < 1500, or 75 < n < 1000. Aspect 2: The cationically modified water-soluble polysaccharide according to Aspect 1, wherein the water-soluble polysaccharide is modified by a method selected from the group consisting of etherification, esterification, amidation, and amination. Aspect 3: The cationically modified water-soluble polysaccharide according to Aspects 1 to 2, wherein the ionic density (ions on the backbone) is 5% - 200%, 5% - 150%, or 10% - 100%. Aspect 4: The cationically modified water-soluble polysaccharide is chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, 4. The cationically modified water-soluble polysaccharide according to any one of claims 1 to 3, wherein the cationically modified water-soluble polysaccharide is selected from the group consisting of chitosan-triazolium iodide salt, dextran-imidazolium chloride salt, dextran-ethyleneguanidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, and dextran-trialkylphosphonium / triphenylphosphonium mixed bromide. Aspect 5: A chemical mechanical planarizing composition comprising the cationically modified water-soluble polysaccharide of Aspects 1-4. Aspect 6: A chemical mechanical planarization composition comprising: an abrasive selected from the group consisting of inorganic oxide particles, metal oxide-coated inorganic oxide particles, organic polymer particles, metal oxide-coated organic polymer particles, and combinations thereof; (1) A cation-modified water-soluble polysaccharide according to any one of (1) to (4). Water, and optionally activator, oxidizing agents, corrosion inhibitors, dishing reducing agent, stabilizers, pH adjuster, included. Aspect 7: A system for chemical mechanical planarization comprises: a semiconductor substrate having at least one surface containing tungsten; A polishing pad; and the chemical mechanical planarization composition of any one of aspects 5-6, At least one surface containing tungsten is in contact with the polishing pad and the chemical mechanical planarization composition. Aspect 8: A polishing method for chemical mechanical planarization of a semiconductor substrate, comprising: at least one surface containing tungsten; a) contacting at least one surface containing tungsten with a polishing pad; b) delivering a chemical mechanical planarization composition according to any one of embodiments 5-6; c) polishing at least one surface containing tungsten with a chemical mechanical planarization composition.

[0026] Abrasives include, but are not limited to, inorganic oxide particles, metal oxide coated inorganic oxide particles, organic polymer particles, metal oxide coated organic polymer particles, surface modified inorganic oxide particles, and combinations thereof.

[0027] Inorganic oxide particles include, but are not limited to, ceria, colloidal silica, high purity colloidal silica, fumed silica, colloidal ceria, alumina, titania, and zirconia particles.

[0028] Metal oxide-coated inorganic oxide particles include, but are not limited to, ceria-coated inorganic oxide particles, such as ceria-coated colloidal silica, ceria-coated high-purity colloidal silica, ceria-coated alumina, ceria-coated titania, ceria-coated zirconia, or any other ceria-coated inorganic oxide particles.

[0029] Organic polymer particles include, but are not limited to, polystyrene particles, polyurethane particles, polyacrylate particles, or any other organic polymer particles.

[0030] The metal oxide-coated organic polymer particles are selected from the group consisting of ceria-coated organic polymer particles and zirconia-coated organic polymer particles.

[0031] The concentration of the abrasive can range from 0.01% to 30% by weight, preferably from about 0.05% to about 20% by weight, more preferably from about 0.01 to about 10% by weight, and most preferably from 0.1% to 2% by weight. Weight percentages are based on the composition.

[0032] Activators include, but are not limited to, (1) inorganic oxide particles coated with a transition metal, the transition metal being selected from the group consisting of Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) soluble catalysts selected from the group consisting of iron (III) nitrate, ammonium iron (III) oxalate trihydrate, iron (III) citrate tribasic monohydrate, iron (III) acetylacetonate, and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate; and (3) metal compounds having multiple oxidation states selected from the group consisting of Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V, and combinations thereof.

[0033] The activator ranges from 0.00001% to 5.0% by weight, from 0.0001% to 2.0% by weight, from 0.0005% to 1.0% by weight, or from 0.001% to 0.5% by weight.

[0034] Oxidizing agents include, but are not limited to, peroxy compounds selected from the group consisting of hydrogen peroxide, urea peroxide, peroxyformic acid, peracetic acid, propane peroxoacids, substituted or unsubstituted butane peroxoacids, hydroperoxyacetaldehyde, potassium periodate, and ammonium peroxymonosulfate, and non-peroxy compounds selected from the group consisting of ferric nitrite, KClO4, KBrO4, and KMnO4.

[0035] The oxidizer concentration can range from about 0.01% to 30% by weight, with a preferred concentration of oxidizer being from about 0.1% to 20% by weight, and a more preferred concentration of oxidizer being from about 0.5% to about 10% by weight. Weight percentages are based on the composition.

[0036] Typical amounts of additives including phosphonium-based polymers or copolymers range from 0.00001 wt % to 1.0 wt %, 0.0001 wt % to 0.5 wt %, 0.00025 wt % to 0.1 wt %, or 0.0005 wt % to 0.05 wt %.

[0037] Suitable pH adjusters for lowering the pH of the polishing composition include, but are not limited to, nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids, and mixtures thereof. Suitable pH adjusters for raising the pH of the polishing composition include, but are not limited to, potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof.

[0038] The pH of the slurry is 1-14, preferably 1-7, more preferably 1-6, and most preferably 1.5-4.

[0039] The CMP slurry may further include surfactants, dispersants, chelating agents, film-forming corrosion inhibitors, and biocides.

[0040] Other aspects, features and embodiments of the present invention will become more fully apparent from the following disclosure and appended claims.

[0041] The embodiments of the present invention may be used alone or in combination with each other. DETAILED DESCRIPTION OF THE INVENTION

[0042] The present invention fills this need by providing an intelligently designed tungsten CMP slurry, a system and method for using the CMP slurry, to reduce the noted problems of dishing and erosion in highly selective slurries while maintaining desirable polishing of metal layers, particularly tungsten films.

[0043] More specifically, the present invention discloses tailored cationically modified water-soluble polysaccharides in which cations are pendant to the water-soluble polysaccharide backbone, the synthesis of the cationically modified water-soluble polysaccharides, and the use of the cationically modified water-soluble polysaccharides in CMP slurries.

[0044] A variety of functional groups can be attached to the water-soluble polysaccharide backbone (from bulky groups to groups with less steric hindrance) to fine-tune the performance and properties of the cationically modified water-soluble polysaccharide. The use of cationically modified polysaccharides can be advantageous because several water-soluble polysaccharides are commercially available.

[0045] Surprisingly, cationically modified water-soluble polysaccharides exhibited high selectivity, low dishing, and low erosion behavior. Furthermore, a high number of modified repeating units could improve the solubility of the polysaccharides. This unique class of polymers can be used as topography-controlling additives and is a valuable tool for designing next-generation slurries.

[0046] All references cited in this specification, including publications, patent applications, and patents, are herein incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein.

[0047] In the context of describing the present invention (particularly in the context of the claims below), the use of the terms "a," "an," and "the," and similar references, should be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" should be construed as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise indicated. The recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated herein as if it were individually recited herein. All methods described herein can be performed in any suitable order, unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "such as") provided herein is intended merely to better elucidate the invention and does not impose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. The use of the term "comprising" in this specification and claims includes the narrower language of "consisting essentially of" and "consisting of."

[0048] Embodiments are described herein, including the best mode known to the inventors for carrying out the invention. Variations of these embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors anticipate that skilled artisans will employ such variations as necessary, and the inventors intend that the invention may be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Furthermore, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or clearly contradicted by context.

[0049] For ease of reference, a "microelectronic device" corresponds to semiconductor substrates, flat panel displays, phase change memory devices, solar panels and other products including solar substrates, photovoltaic devices, and microelectromechanical systems (MEMS) manufactured for use in microelectronics, integrated circuits, or computer chip applications. Solar substrates include, but are not limited to, silicon, amorphous silicon, polycrystalline silicon, single crystal silicon, CdTe, copper indium selenide, copper indium sulfide, and gallium arsenide on gallium. Solar substrates may be doped or undoped. It should be understood that the term "microelectronic device" is not intended to be limiting in any way and includes any substrate that ultimately becomes a microelectronic device or microelectronic assembly.

[0050] "Substantially free" is defined herein as less than 0.001% by weight. "Substantially free" also includes 0.000% by weight. The term "free" means 0.000% by weight.

[0051] As used herein, "about" is intended to correspond to ±5%, preferably ±2% of the stated value.

[0052] In all such compositions where a particular component of a composition is discussed with reference to a weight percent range that includes a lower limit of zero, it will be understood that such component may or may not be present in various particular embodiments of the composition, and that when such component is present, such component may be present in concentrations as low as 0.00001 weight percent, based on the total weight of the composition in which such component is used.

[0053] There are several specific aspects to the present invention.

[0054] One embodiment is for synthesizing a cationically modified water-soluble polysaccharide by modifying a water-soluble polysaccharide by a method selected from the group consisting of etherification, esterification, amidation, and amination.

[0055] Another embodiment is a CMP slurry containing an abrasive, an additive containing a cationically modified water-soluble polysaccharide, and water, and optionally an oxidizing agent, an activator or catalyst, a corrosion inhibitor, a dishing-reducing agent, a stabilizer, and a pH adjuster. The pH of the slurry is 1 to 14, preferably 1 to 7, more preferably 1 to 6, and most preferably 1.5 to 4.

[0056] The CMP slurry may further include surfactants, dispersants, chelating agents, film-forming corrosion inhibitors, biocides, and polishing enhancers.

[0057] Yet another aspect is a system for chemical mechanical planarization, comprising: a semiconductor substrate having at least one surface containing tungsten; A polishing pad; a chemical mechanical planarization composition; A system for chemical mechanical planarization in which at least one surface containing tungsten is in contact with a polishing pad and a chemical mechanical planarization composition.

[0058] Yet another aspect is a polishing method for chemical mechanical planarization of a semiconductor substrate having at least one surface containing tungsten, comprising: contacting the at least one surface containing tungsten with a polishing pad; delivering a chemical mechanical planarization composition; polishing the at least one surface containing tungsten with a chemical mechanical planarization composition.

[0059] The CMP slurry in the present invention comprises a polycationic polymer or copolymer.

[0060] More specifically, the CMP slurry contains an abrasive, a polycationic polymer or copolymer, an oxidizer, an activator or catalyst, additives, and water, and optionally a corrosion inhibitor, a dishing reducer, a stabilizer, and a pH adjuster. The pH of the slurry is 1 to 14, preferably 1 to 7, more preferably 1 to 6, and most preferably 1.5 to 4.

[0061] The CMP slurry may further include surfactants, dispersants, chelating agents, film-forming corrosion inhibitors, biocides, and polishing enhancers. abrasives

[0062] Abrasives used in CMP slurries include, but are not limited to, inorganic oxide particles, metal oxide-coated inorganic oxide particles, organic polymer particles, metal oxide-coated organic polymer particles, surface-modified abrasive particles, such as cation- or anion-modified abrasive particles, and combinations thereof.

[0063] The abrasives used in the CMP slurry may be activator-containing particles (ie, abrasives having an activator coating) or non-activator-containing particles.

[0064] Inorganic oxide particles include, but are not limited to, ceria, silica, alumina, titania, germania, spinel, tungsten oxides or nitrides, zirconia particles, or any of the above doped with one or more other minerals or elements, and any combination thereof. Oxide abrasives can be produced by any of a variety of techniques, including sol-gel, hydrothermal, hydrolysis, plasma, pyrolysis, aerogel, fuming, and precipitation methods, and any combination thereof.

[0065] Precipitated inorganic oxide particles can be obtained by known methods by reacting metal salts with acids or other precipitating agents. Pyrolytic metal oxide and / or metalloid oxide particles can be obtained by hydrolysis of suitable vaporizable starting materials in an oxygen / hydrogen flame. One example is pyrolytic silicon dioxide from silicon tetrachloride. Pyrolytic oxides of aluminum oxide, titanium oxide, zirconium oxide, silicon dioxide, cerium oxide, germanium oxide, and vanadium oxide, as well as chemical and physical mixtures thereof, are suitable.

[0066] Metal oxide-coated inorganic oxide particles include, but are not limited to, ceria-coated or alumina-coated inorganic oxide particles, such as ceria-coated colloidal silica, alumina-coated colloidal silica, ceria-coated high-purity colloidal silica, alumina-coated high-purity colloidal silica, ceria-coated alumina, ceria-coated titania, alumina-coated titania, ceria-coated zirconia, alumina-coated zirconia, or any other ceria-coated or alumina-coated inorganic oxide particles.

[0067] The metal oxide coated organic polymer particles are selected from the group consisting of ceria coated organic polymer particles and zirconia coated organic polymer particles.

[0068] Organic polymer particles include, but are not limited to, polystyrene particles, polyurethane particles, polyacrylate particles, or any other organic polymer particles.

[0069] Colloidal silica particles and high-purity colloidal silica particles are preferred abrasive particles. The silica may be precipitated silica, fumed silica, pyrogenic silica, silica doped with one or more adjuvants, or any other silica-based compound.

[0070] Colloidal silica particles and high-purity colloidal silica particles used as abrasives also include silica particles that have been surface-chemically modified via chemical coupling reactions, which allow the silica particle surface to have different chemical functional groups and to have positive or negative charges under different application pH conditions in the CMP slurry. Examples of such surface-chemically modified silica particles include, but are not limited to, SiO2-R-NH2, -SiO-R-SO3M, where R is, for example, (CH2) where n is in the range of 1 to 12. n M may be, for example, sodium, potassium, or ammonium.

[0071] In alternative embodiments, the silica may be produced by a process selected from the group consisting of, for example, a sol-gel process, a hydrothermal process, a plasma process, a fuming process, a precipitation process, and any combination thereof.

[0072] The abrasive is generally in the form of abrasive particles, typically many abrasive particles, of one material or a combination of different materials. Generally, suitable abrasive particles are approximately spherical and have an effective diameter of about 10 to 700 nm, about 20 to 500 nm, or about 30 to 300 nanometers (nm), although individual particle sizes can vary. Abrasives in the form of agglomerated or weakly agglomerated particles are preferably further processed to form individual abrasive particles.

[0073] The abrasive particles may be purified using a suitable method, such as ion exchange, to remove metal impurities, which may help improve colloidal stability. Alternatively, high purity abrasive particles are used.

[0074] Generally, the above-mentioned abrasives can be used alone or in combination with each other. To obtain superior performance, it may be advantageous to combine two or more abrasive particles having different sizes or different types of abrasives.

[0075] The concentration of the abrasive may range from 0.01% to 30% by weight, preferably from about 0.05% to about 20% by weight, more preferably from about 0.01 to about 10% by weight, and most preferably from 0.1% to 2% by weight. Weight percentages are based on the composition. additives

[0076] The CMP slurry of the present invention includes an additive that is a tailored modified water-soluble polysaccharide in which cations are pendant to the polysaccharide backbone.

[0077] Positively charged polymers generally can electrostatically interact with negatively charged surfaces, such as negatively charged metal surfaces. In this application, the positively charged polycationic polymer electrostatically interacts with the oxidized W surface, creating a negative charge on the surface. Therefore, by using an optimized amount and tailored polymer, the selectivity between metal removal and oxide layer removal can be significantly increased while reducing the dishing effect.

[0078] At low pH values ​​<2.5, the SiO2 layer, as a classical standard oxide material, is never partially positively charged. In other words, to prevent oxide erosion simultaneously with metal dishing, the polymers used require a more tailored design beyond a purely cationic approach.

[0079] Surprisingly, CMP slurries using cationically modified water-soluble polysaccharides increased the RR of W but suppressed the RR of TEOS, thus significantly increasing the W:TEOS removal selectivity. Furthermore, dishing was significantly reduced in CMP slurries using water-soluble polysaccharides modified with cations pendant on the polysaccharide backbone. This unique class of polymers can be used as topography-controlling additives and is a valuable tool for designing next-generation slurries.

[0080] The cationically modified water-soluble polysaccharide comprises a cationic monomer having a structure selected from the group consisting of: [ka] During the ceremony, the water-soluble polysaccharide is selected from the group consisting of chitosan, pectin, dextran, pullulan, and inulin; The pentagon or hexagon represents the backbone of the water-soluble polysaccharide; Z is selected from the group consisting of NH—S—, —O—(C═O)—, —NH—(C═O)—, —O—(C═O)—, —NH—(C═O)—, and NR′, where R′ is an alkyl having C1 to C6 and is a carbon-carbon double or triple bond as shown below: [ka] The two carbon atoms in the double bond structure can be connected to two protons, or one proton and one alkyl group R'', where R is an alkyl group having C1 to C6, or two identical alkyl groups R'', or two different alkyl groups R and R''', where R is an alkyl group having C1 to C6; Preferably, Z represents NH or —O—, Sp represents, at each occurrence, the presence of a spacer group having a single or double bond structure, preferably a single bond structure; Y + is N + , P + , S +represents a cationic functional group such as, and the cationically modified water-soluble polysaccharide contains repeating units that do not contain ions or contain at least one ion, for example, one ion, two ions or three ions, X - is an anion that can be a halide (F - , Cl - , Br - , I - ), BF4 - , CF3BF3 - , OH - , PF6 - , carboxylate, malonate, citrate, carbonate, fumarate, MeOSO3 - , MeSO3 - , CF3COO - , CF3SO3 - , cyanate, isothiocyanate, nitrate, phosphate or sulfate, R represents a cationic side group selected from the group consisting of H, CH3, an alkyl chain (saturated or unsaturated, branched or aliphatic), a cyclic ring, for example, a phenyl ring, and other functional groups, for example, an amine, a carboxylic acid, a sulfonate, a siloxane, an ether, an alcohol, another cation, and other side groups, and (R)3 forms a ring selected from the group consisting of alkyl or imidazolium, triazolium, and tetrazolium, tris-alkylphosphonium, tris-phenylphosphonium, tris-alkylsulfonium, tris-phenylsulfonium, n represents the number of repeating units, and 1 < n < 2000, 50 < n < 1500, or 75 < n < 1000.

[0081] To modify the water-soluble polysaccharide backbone, different reactions can be carried out. The most preferred modifications are etherification, esterification, amidation, amination, or modifications by double bonds and triple bonds because they are stable under polishing conditions (pH and local high temperature). Other modification methods can be implemented, such as by amide, amine, or any other type of bond that is stable under polishing conditions.

[0082] The number of ions on the backbone, i.e., ion density, can be varied by changing the reaction conditions so that there are no ions, one ion, or two or more ions on a single repeat unit. The ion density can be calculated using nuclear magnetic resonance (NMR), silver nitrate precipitation, conductivity, or any other analytical method. The ion density can be 5 to 200%, 5 to 150%, or 10 to 100%, and is calculated by dividing the total number of ions in the cation-modified water-soluble polysaccharide by the total number of repeat units of the water-soluble polysaccharide before modification.

[0083] The concentration of the additive can range from 0.00001% to 1.0%, 0.0001% to 0.5%, 0.00025% to 0.1%, or 0.0005% to 0.05% by weight. The weight percentages are of the composition. oxidizing agent

[0084] Contains an oxidizing agent or substance for chemical etching of materials.

[0085] The oxidizer of the CMP slurry is in a fluid composition that is in contact with the substrate and aids in the chemical removal of target materials on the substrate surface. Thus, the oxidizer component is believed to enhance or increase the material removal rate of the composition. Preferably, the amount of oxidizer in the composition is sufficient to assist the chemical removal process, but is as low as possible to minimize similar or related issues, such as handling, environmental concerns, or cost.

[0086] Advantageously, in one embodiment of the present invention, the oxidizing agent is a component that generates free radicals upon exposure to at least one activating agent, which increase the etch rate on at least selected structures. The free radicals described below oxidize most metals, making the surface more susceptible to oxidation from other oxidizing agents. However, because some oxidizing agents do not readily form free radicals upon exposure to an activating agent, and in some embodiments, it is advantageous to have one or more oxidizing agents that provide tailored or preferential etch rates for various combinations of metals that may be found on a substrate, oxidizing agents are listed separately from the "compounds that generate free radicals" discussed below.

[0087] As is known in the art, some oxidizers are more suitable for certain components than others. In some embodiments of the present invention, the selectivity of a CMP system for one metal as opposed to another is maximized, as is known in the art. However, in certain embodiments of the present invention, the combination of oxidizers is selected to provide substantially similar CMP rates (as opposed to simply etch rates) for the combination of conductor and barrier.

[0088] In one embodiment, the oxidizing agent is an inorganic or organic percompound.

[0089] Percompounds are generally defined as compounds containing elements in their highest oxidation state, such as perchloric acid, or compounds containing at least one peroxy group (-OO-), such as peracetic acid and perchromate.

[0090] Suitable per-compounds containing at least one peroxy group include, but are not limited to, peracetic acid or its salts, percarbonates, and organic peroxides such as benzoyl peroxide, urea peroxide, and / or di-t-butyl peroxide.

[0091] Suitable per-compounds containing at least one peroxy group include peroxides. As used herein, the term "peroxide" encompasses ROO-R', where R and R' are each independently H, C1-C6 linear or branched alkyl, alkanol, carboxylic acid, ketone (for example), or amine, each of which may be independently substituted with one or more benzyl groups (e.g., benzoyl peroxide), which may themselves be substituted with OH or C1-C5 alkyl, as well as salts and adducts thereof. Thus, the term encompasses common examples such as hydrogen peroxide, peroxyformic acid, peracetic acid, propane peroxoic acid, substituted or unsubstituted butane peroxoic acid, hydroperoxy-acetaldehyde, and the like, and also encompasses common complexes of peroxides, such as urea peroxide.

[0092] Suitable percompounds containing at least one peroxy group include persulfates. As used herein, the term "persulfates" includes monopersulfates, dipersulfates, and their acids, salts, and adducts. Examples include peroxydisulfates, peroxymonosulfates, and / or peroxymonosulfates, Caro's acid, and salts such as potassium peroxymonosulfate, but preferably non-metal salts such as ammonium peroxymonosulfate.

[0093] Suitable per-compounds containing at least one peroxy group include perphosphates, including peroxydiphosphates, as defined above.

[0094] Ozone is also a suitable oxidizing agent, either alone or in combination with one or more other suitable oxidizing agents.

[0095] Suitable per-compounds that do not contain a peroxy group include, but are not limited to, periodic acid and / or any salt of periodate (hereinafter "periodate"), perchloric acid and / or any salt of perchlorate (hereinafter "perchlorate"), perbromic acid and / or any salt of perbromate (hereinafter "perbromate"), and perboric acid and / or any salt of perborate (hereinafter "perbromate").

[0096] Other oxidizing agents are also suitable components of the compositions of the present invention. Iodate is a useful oxidizing agent.

[0097] Two or more oxidizers may be combined to provide synergistic performance benefits.

[0098] In most embodiments of the present invention, the oxidizing agent is selected from the group consisting of peroxy compounds selected from the group consisting of hydrogen peroxide, urea peroxide, peroxyformic acid, peracetic acid, propane peroxoacids, substituted or unsubstituted butane peroxoacids, hydroperoxyacetaldehyde, potassium periodate, and ammonium peroxymonosulfate, and non-peroxy compounds selected from the group consisting of ferric nitrite, KClO, KBrO, and KMnO.

[0099] In some embodiments, the preferred oxidizing agent is hydrogen peroxide.

[0100] The oxidizer concentration can range from about 0.01% to 30% by weight, with a preferred concentration of oxidizer being from about 0.1% to 20% by weight, and a more preferred concentration of oxidizer being from about 0.5% to about 10% by weight. Weight percentages are based on the composition. activator

[0101] An activator or catalyst is a material that promotes the formation of free radicals by at least one free radical-producing compound present in the fluid interacting with an oxidizer.

[0102] The activator may be a metal-containing compound, particularly a metal selected from the group consisting of metals known to activate the Fenton reaction process in the presence of an oxidizing agent such as hydrogen peroxide.

[0103] The activator may also be a non-metal-containing compound. Iodine, for example, is useful for forming free radicals with hydrogen peroxide.

[0104] If the activator is a metal ion or metal-containing compound, the activator is present in a thin layer attached to the surface of a solid in contact with the fluid. If the activator is a non-metal-containing material, the activator can be dissolved in the fluid. The activator is preferably present in an amount sufficient to promote the desired reaction.

[0105] Activators include, but are not limited to, (1) inorganic oxide particles coated with a transition metal, wherein the transition metal is selected from the group consisting of iron, copper, manganese, cobalt, cerium, and combinations thereof; and (2) soluble catalysts, such as iron (III) nitrate, ammonium iron (III) oxalate trihydrate, tribasic iron (III) citrate monohydrate, iron (III) acetylacetonate, and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate, Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V, and metal compounds having multiple oxidation states selected from the group consisting of these.

[0106] The amount of activator in the slurry ranges from about 0.00001% to 5% by weight, preferably from about 0.0001% to 2.0% by weight, more preferably from about 0.0005% to 1.0% by weight, and most preferably from 0.001% to 0.5% by weight. water

[0107] The polishing composition is water-based and therefore contains water.In the composition, water functions in various ways, for example, to dissolve one or more solid components of the composition, as a carrier of the components, as an aid in removing polishing residues, and as a diluent.Preferably, the water used in the cleaning composition is deionized (DI) water.

[0108] For most applications, the water content will be, for example, from about 10 to about 90% or 90% by weight water. Other preferred embodiments may include from about 30 to about 95% by weight water. Still other preferred embodiments may include from about 50 to about 90% by weight water. Still other preferred embodiments may include water in an amount to achieve the desired weight percentages of the other ingredients. Corrosion inhibitor (optional)

[0109] Corrosion inhibitors for use in the CMP compositions disclosed herein include, but are not limited to, nitrogen-containing cyclic compounds such as 1,2,3-triazole, 1,2,4-triazole, 1,2,3-benzotriazole, 5-methylbenzotriazole, benzotriazole, 1-hydroxybenzotriazole, 4-hydroxybenzotriazole, 3-amino-1,2,4-triazole, 4-amino-4H-1,2,4-triazole, 5-aminotriazole, benzimidazole, benzothiazoles such as 2,1,3-benzothiadiazole, triazine thiols, triazine dithiols, and triazine trithiols, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and mixtures thereof. Preferred corrosion inhibitors are 1,2,4-triazole, 5-aminotriazole, and 1,3,5-tris(2-hydroxyethyl)isocyanurate.

[0110] The amount of corrosion inhibitor in the slurry ranges from less than 1.0 wt%, preferably less than 0.5 wt%, or more preferably less than 0.25 wt%. dishing reducer (optional)

[0111] The CMP composition may further comprise a dishing-reducing agent or dishing reducer selected from the group consisting of sarcosinates and related carboxylic acid compounds, hydrocarbon-substituted sarcosinates, amino acids, organic polymers and copolymers with molecules containing ethylene oxide repeat units such as polyethylene oxide (PEO), ethoxylated surfactants, nitrogen-containing heterocycles without nitrogen-hydrogen bonds, sulfides, oxazolidines, or mixtures of functional groups in one compound, nitrogen-containing compounds with three or more carbon atoms that form alkylammonium ions, aminoalkyls with three or more carbon atoms, polymeric corrosion inhibitors containing at least one nitrogen-containing heterocycle or tertiary or quaternary nitrogen atom repeat group, polycationic amine compounds, cyclodextrin compounds, polyethyleneimine compounds, glycolic acid, chitosan, sugar alcohols, polysaccharides, alginate compounds, and sulfonic acid polymers. Glycine is a preferred dishing-reducing agent.

[0112] When present, the amount of dishing reducing agent ranges from about 0.001 wt % to 2.0 wt %, preferably 0.005 wt % to 1.5 wt %, and more preferably 0.01 wt % to 1.5 wt %, based on weight per weight of the total CMP composition. Stabilizer (optional)

[0113] The composition may also include one or more of a variety of optional additives. Suitable optional additives include stabilizers. These optional additives are generally used to facilitate or promote stabilization of the composition against settling, aggregation (including particle precipitation, strong or weak aggregation, etc.), and decomposition. Stabilizers can be used to extend the working life of oxidizers containing compounds that generate free radicals by isolating activator materials, quenching free radicals, or otherwise stabilizing compounds that form free radicals.

[0114] Several materials are useful for stabilizing hydrogen peroxide. One exception to metal contamination is the presence of selected stabilizing metals, such as tin. In some embodiments of the present invention, tin can be present in small amounts, typically less than about 25 ppm, e.g., about 3 to about 20 ppm. Similarly, zinc is often used as a stabilizer. In some embodiments of the present invention, zinc can be present in small amounts, typically less than about 20 ppm, e.g., about 1 to about 20 ppm. In another preferred embodiment, the fluid composition contacting the substrate has less than 500 ppm, e.g., less than 100 ppm, of dissolved metals, excluding tin and zinc, having multiple oxidation states. In the most preferred commercial embodiment of the present invention, the fluid composition contacting the substrate has less than 9 ppm of dissolved metals, excluding tin and zinc, having multiple oxidation states, e.g., less than 2 ppm of dissolved metals, excluding tin and zinc. In some preferred embodiments of the present invention, the fluid composition contacting the substrate has less than 50 ppm, preferably less than 20 ppm, and more preferably less than 10 ppm of dissolved total metals, excluding tin and zinc.

[0115] Since metals in solution are generally not recommended, non-metal-containing oxidizing agents that are typically present in salt form, e.g., persulfates, are preferably in acid form and / or ammonium salt form, e.g., ammonium persulfate.

[0116] Other stabilizers include free radical quenchers. As mentioned above, these attenuate the effects of generated free radicals. Therefore, if present, they are preferably present in small amounts. Most antioxidants, such as vitamin B, vitamin C, and citric acid, are free radical quenchers. While most organic acids are free radical quenchers, three that are effective and have other beneficial stabilizing properties are phosphonic acid, the binder oxalic acid, and the non-radical sequestering agent gallic acid.

[0117] Additionally, carbonates and phosphates are believed to bind to the activator and prevent fluid access. Carbonates are particularly useful because they can be used to stabilize the slurry, although small amounts of acid can quickly remove the stabilizing ions. Useful stabilizing agents for absorbed activators can be film-forming agents that form a film on the silica particles.

[0118] Suitable stabilizers include organic acids such as adipic acid, phthalic acid, citric acid, malonic acid, orthophthalic acid, and phosphoric acid, substituted or unsubstituted phosphonic acids, i.e., phosphonate compounds, nitriles, and other ligands, such as those that bind to activator materials and thereby reduce reactions that decompose oxidizers, as well as any combination of the aforementioned agents. As used herein, the term "acid stabilizing agent" refers to both the acid stabilizer and its conjugate base. That is, various acid stabilizers can also be used in their conjugated form. By way of example, for the acid stabilizers mentioned above, the adipic acid stabilizer includes adipic acid and / or its conjugate base, and the carboxylic acid stabilizer includes a carboxylic acid and / or its conjugate base, carboxylate, etc. Suitable stabilizers, used alone or in combination with one or more other stabilizers, reduce the rate at which an oxidizer, such as hydrogen peroxide, decomposes when incorporated into a CMP slurry.

[0119] On the other hand, the presence of a stabilizer in the composition may impair the effectiveness of the activator. The amount should be adjusted to meet the required stability while minimizing adverse effects on the effectiveness of the CMP system. Generally, any of these optional additives should be present in an amount sufficient to substantially stabilize the composition. The required amount will vary depending on the specific additive selected and the specific configuration of the CMP composition, such as the surface properties of the abrasive component. If too little additive is used, the additive will have little or no effect on the stability of the composition. On the other hand, if too much additive is used, the additive may contribute to the formation of undesirable bubbles and / or flocculants in the composition.

[0120] Generally, suitable amounts of these stabilizers range from about 0.0001 to 5% by weight, preferably from about 0.00025 to 2% by weight, and more preferably from about 0.0005 to about 1% by weight of the composition. The stabilizer may be added directly to the composition or may be applied to the surface of the abrasive component of the composition. pH adjuster (optional)

[0121] The compositions disclosed herein contain a pH adjuster. The pH adjuster is typically used in the compositions disclosed herein to increase or decrease the pH of the polishing composition. The pH adjuster can be used, as needed, to improve the stability of the polishing composition, adjust the ionic strength of the polishing composition, and improve safety in handling and use.

[0122] Suitable pH adjusters for lowering the pH of the polishing composition include, but are not limited to, nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids, and mixtures thereof. Suitable pH adjusters for raising the pH of the polishing composition include, but are not limited to, potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof.

[0123] When used, the amount of the pH adjuster is preferably in the range of about 0.01% to about 5.0% by weight, based on the total weight of the polishing composition, with a preferred range being about 0.01% to about 1% by weight or about 0.05% to about 0.15% by weight.

[0124] The pH of the slurry is 1-14, preferably 1-7, more preferably 1-6, and most preferably 1.5-4. Surfactant (optional)

[0125] The composition disclosed herein optionally contains a surfactant, which in part protects the wafer surface during and after polishing and helps reduce defects on the wafer surface.Surfactants can also be used to control the removal rate of some of the films used during polishing, such as the removal rate of low-k dielectrics.Suitable surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof.

[0126] Nonionic surfactants can be selected from a range of chemical types including, but not limited to, long chain alcohols, ethoxylated alcohols, ethoxylated acetylenic diol surfactants, polyethylene glycol alkyl ethers, propylene glycol alkyl ethers, glucoside alkyl ethers, polyethylene glycol octylphenyl ethers, polyethylene glycol alkylphenyl ethers, glycerol alkyl esters, polyoxyethylene glycol sorbitone alkyl esters, sorbitone alkyl esters, cocamide monoethanolamine, cocamide diethanolamine dodecyldimethylamine oxide, block copolymers of polyethylene glycol and polypropylene glycol, polyethoxylated tallow amine, fluorosurfactants.

[0127] The molecular weight of surfactants can range from a few hundred to over a million. The viscosity of these materials also has a very wide distribution.

[0128] Anionic surfactants include, but are not limited to, alkyl carboxylates, alkyl polyacrylates, alkyl sulfates, alkyl phosphates, alkyl bicarboxylates, alkyl bisulfates, alkyl biphosphates, and salts with suitable hydrophobic tails, such as alkoxy carboxylates, alkoxy sulfates, alkoxy phosphates, alkoxy bicarboxylates, alkoxy bisulfates, and alkoxy biphosphates, including substituted aryl carboxylates, substituted aryl sulfates, substituted aryl phosphates, substituted aryl bicarboxylates, substituted aryl bisulfates, and substituted aryl biphosphates. Counterions of these surfactants include, but are not limited to, potassium ions, ammonium ions, and other cations. The molecular weights of these anionic surface wetting agents range from several hundred to several hundred thousand.

[0129] Cationic surfactants have a net positive charge on the main part of the molecular backbone and are typically molecules containing a hydrophobic chain and a cationic charge center, such as amine, quaternary ammonium, benzalkonium, and alkylpyridinium ion halides.

[0130] In another embodiment, the surfactant may be an amphoteric surfactant, which has both positive (cationic) and negative (anionic) charges on the main molecular chain and their corresponding counterions. The cationic portion is based on a primary, secondary, or tertiary amine or a quaternary ammonium cation. The anionic portion may be more variable and may include a sulfonate, as in sultaine CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) and cocamidopropyl hydroxysultaine. Betaines, such as cocamidopropyl betaine, have a carboxylate with ammonium. Some amphoteric surfactants may have a phosphate anion with an amine or ammonium, such as the phospholipids phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelin.

[0131] Examples of surfactants include, but are not limited to, sodium dodecyl sulfate, sodium lauryl sulfate, ammonium dodecyl sulfate, secondary alkane sulfonates, alcohol ethoxylates, acetylenic surfactants, and any combination thereof. Examples of suitable commercially available surfactants include the TRITON®, Tergitol®, and DOWFAX® families of surfactants manufactured by Dow Chemicals, as well as various surfactants in the SURFYNOL®, DYNOL®, Zetasperse®, Nonidet®, and Tomadol® surfactant families manufactured by Air Products and Chemicals. Suitable surfactants among surfactants can also include polymers containing ethylene oxide (EO) and propylene oxide (PO) groups. An example of an EO-PO polymer is Tetronic® 90R4 manufactured by BASF Chemicals.

[0132] When used, the amount of surfactant typically ranges from 0.0001% to about 1.0% by weight, based on the total weight of the barrier CMP composition. When used, the preferred range is from about 0.010% to about 0.1% by weight. Chelating agent (optional)

[0133] Chelating agents can be optionally used in the compositions disclosed herein to enhance the affinity of the chelating ligand for metal cations. Chelating agents can also be used to prevent the accumulation of metal ions on the pad, which can cause pad contamination and instability in removal rate. Suitable chelating agents include, for example, amine compounds such as ethylenediamine, ethylenediaminetetraacetic acid (EDTA), aminopolycarboxylic acids such as nitrilotriacetic acid (NTA), benzenesulfonic acid, 4-tolylsulfonic acid, 2,Aromatic acids such as 4-diamino-benzosulfonic acid, non-aromatic organic acids such as itaconic acid, malic acid, malonic acid, tartaric acid, citric acid, oxalic acid, gluconic acid, lactic acid, mandelic acid, or salts thereof, various amino acids and their derivatives, for example, glycine, serine, proline, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, ornithine, selenoside, hydroxybenzoates ... Stain, tyrosine, sarcosine, vicine, tricine, aceglutamide, N-acetylaspartic acid, acetylcarnitine, acetylcysteine, N-acetylglutamic acid, acetylleucine, acivicin, S-adenosyl-L-homocysteine, agaritine, alanosine, aminohippuric acid, L-arginine ethyl ester, aspartame, aspartylglucosamine, benzylmercaptouric acid, biocytin, brivanib alanine acid, carbocysteine, N(6)-carboxymethyllysine, carbocysteine Glumic acid, cilastatin, cithiolone, coprine, dibromotyrosine, dihydroxyphenylglycine, eflornithine, fenclonine, 4-fluoro-L-threonine, N-formylmethionine, gamma-L-glutamyl-L-cysteine, 4-(gamma-glutamylamino)butanoic acid, glutaurine, glycocyamine, hadacidin, hepapressin, lisinopril, lymecycline, N-methyl-D-aspartic acid, N-methyl-L-glutamic acid, milacemide, nitrosoproline, nocardicin A, nopa Examples of anti-inflammatory agents include, but are not limited to, phosphonates, octopine, ombrabulin, opine, orsanilic acid, oxaceprol, polylysine, remacemide, salicylic acid, silk amino acids, stampeidin, tabtoxin, tetrazolylglycine, thiorphan, timectacin, tiopronin, tryptophan tryptophylquinone, valacyclovir, valganciclovir, phosphonic acids and derivatives thereof, such as octylphosphonic acid, aminobenzylphosphonic acid, and combinations thereof and salts thereof.

[0134] For example, chelating agents may be used where necessary to chemically bond copper and tantalum cations to facilitate dissolution of copper and tantalum oxides to obtain a desired removal rate of copper lines, vias, or trenches and barrier layers or films.

[0135] If used, the amount of chelating agent preferably ranges from about 0.01% to about 3.0% by weight, more preferably from about 0.4% to about 1.5% by weight, based on the total weight of the composition. Biocide (optional)

[0136] The CMP formulations disclosed herein may also include additives for controlling biological growth, such as biocides. Some additives for controlling biological growth are disclosed in U.S. Pat. No. 5,230,833 and U.S. Patent Application Publication No. 2002 / 0025762, which are incorporated herein by reference. Biological growth inhibitors include, but are not limited to, tetramethylammonium chloride, tetraethylammonium chloride, tetrapropylammonium chloride, alkylbenzyldimethylammonium chloride, and alkylbenzyldimethylammonium hydroxide (with alkyl chains ranging from 1 to about 20 carbon atoms), sodium chlorite, sodium hypochlorite, isothiazolinone compounds such as methylisothiazolinone, methylchloroisothiazolinone, and benzisothiazolinone. Some commercially available preservatives include the KATHON® and NEOLENE® product families from Dow Chemicals and the Preventol® family from Lanxess.

[0137] Preferred biocides are isothiozilone compounds such as methylisothiazolinone, methylchloroisothiazolinone and benzisothiazolinone.

[0138] The CMP polishing composition optionally contains a biocide in the range of 0.0001% to 0.10% by weight, preferably 0.0001% to 0.005% by weight, and more preferably 0.0002% to 0.0025% by weight, to prevent bacterial and fungal growth during storage.

[0139] The compositions disclosed herein may be prepared in a concentrated form and then diluted with DI water at the time of use. For example, other components, such as an oxidizer, may be set aside in the form of a concentrate and added at the time of use to minimize incompatibility between components in the form of a concentrate. The compositions disclosed herein may be prepared with two or more components that can be mixed before use. [Example]

[0140] General Experimental Procedures

[0141] All percentages are by weight unless otherwise indicated. Part I. Synthesis of cation-modified water-soluble polysaccharides

[0142] All polysaccharides used in this study are commercially available polymers. Polymer modification can be achieved by adding cations to the polymer backbone. The amount of modification (ion density) can be controlled by the amount of modifier added during the reaction or by the type of ion precursor used (the precursor can contain more than one ion).

[0143] 1-(2-Hydroxy-ethyl)-3-methylimidazolium chloride was purchased from Holland Moran (15 Avraham Giron St., Yehud-Monosson, Israel). Other reagents and dry solvents were purchased from Sigma-Aldrich (3 Plaut St., Rehovot, Israel). All AR-grade solvents were purchased from Bio-Lab (22 HaYettsira St., Jerusalem, Israel). All chemicals were of the highest commercially available grade and were used as received unless otherwise stated.

[0144] All reactions using dextran were carried out using pectin, inulin or pullulan. All reactions carried out using phosphonium salts can be carried out using ammonium salts. Example 1: Chitosan-triphenylphosphonium bromide salt-amine reaction

[0145] Chitosan modification: [ka]

[0146] 4.0 g of chitosan (50-190 kDa) was dissolved in 200 mL of DI water in a flask at 75°C for approximately 1 hour. The solution was cooled to room temperature, and 17.3 mL of triethylamine was added to the flask. The mixture was stirred at room temperature for 5 minutes. 23.77 g of (4-bromobutyl)triphenylphosphanium bromide was then added along with 100 mL of acetonitrile. The reaction mixture was returned to 70°C and heated for 48 hours.

[0147] After cooling to room temperature, a solid precipitated from the solution. The solid was filtered, washed with water, tetrahydrofuran (THF), and dichloromethane (DCM), and dried under vacuum overnight. The ion density was 10-15% (NMR). Example 2: Dextran-triphenylphosphonium bromide salt-hydroxyl reaction

[0148] Dextran modification: [ka]

[0149] 0.5 g of dextran and 3.74 g of NaOH were dissolved in 20 mL of DI water at room temperature. The mixture was stirred at room temperature for several minutes and then heated to 70°C. After 3 hours, the solution was cooled to room temperature and 4.44 g of (4-bromobutyl)triphenylphosphanium bromide was added along with 10 mL of acetonitrile. The reaction mixture was returned to 70°C and heated for 24 hours.

[0150] After cooling to room temperature, 15 mL of 1 M HBr solution was added until the pH reached 6-7. The solvent was evaporated using an evaporator, and the resulting white solid was extracted with approximately 100 mL of water. The water was then evaporated again, and the resulting solid was extracted with DCM. The DCM phase was discarded, and the white solid was dried under vacuum overnight. The ion density was approximately 10% (NMR). Example 3: Imidazolium modification by chitosan-imidazolium chloride salt-tosylation

[0151] Preparation of tosylated imidazolium (Ts-imidazolium): [ka]

[0152] In a 150 mL round-bottom flask, 3.0 g of hydroxyethylmethylimidazolium chloride was dissolved in 30 mL of dimethylformamide (DMF) under an Ar atmosphere (dissolution required heating to approximately 50° C., then cooled to room temperature). The flask was then cooled to 0° C. (using an ice bath) and 3 mL of pyridine was injected.

[0153] A 30 mL solution of TsCl (5.2 g) in THF was placed in a pressure equalizing funnel and added dropwise over approximately 30 minutes with cooling. As the addition continued, a white solid appeared. The reaction mixture was heated at 65°C for 24 hours. When the temperature reached approximately 50°C, the solid dissolved and returned to solution. The color of the solution changed to yellow and then dark green.

[0154] The reaction mixture was cooled to room temperature, concentrated using an evaporator, and passed through column chromatography (silica, chloroform as eluent, then EtOH to extract the product + pyridine).

[0155] Second step - polymer modification: [ka]

[0156] 0.756 g of chitosan, 0.975 g of NaOH, and 2.951 g of Ts-imidazolium chloride were dissolved in 45 mL of DI water and 15 mL of EtOH. The solution was viscous and decreased in viscosity at approximately 50°C. The reaction mixture was heated at 75°C for 24 hours. The solution turned dark brown. The base was neutralized by adding approximately 17 mL of 1.2 M HCl. The solvent was evaporated. The polymer was mixed with 75 mL of EtOH at room temperature overnight. The brown solid was filtered and dried under vacuum.

[0157] The ion density was about 70-80% (NMR). Example 4: Dextran-(2-hydroxy)propyl-triphenylphosphonium chloride salt-modified using epichlorohydrin (hypothetical).

[0158] Dextran is dissolved in deionized water and a mixture of epichlorohydrin and triphenylphosphine is added. The solution is mixed for 6 hours at 70° C. The polymer is precipitated several times with acetone and dialyzed against 0.1 M HCl and water. [ka] Example 5: Pectin-ethylenediaminetriphenylphosphonium bromide salt - Modification of pectin by amidation (hypothetical).

[0159] In the first step, pectin is hydrolyzed to its acid counterpart using the following procedure: Pectin (PT) is dissolved in aqueous NaOH (PT to NaOH molar ratio 1:1). The solution is heated to 50°C for 24 hours. The solid is precipitated from ethanol and dried using a freeze dryer. [ka]

[0160] In the second step, the hydrolyzed pectin is aminated to form PT-NH2 using the following procedure: A 2 wt% aqueous solution of hydrolyzed PT is prepared. Then, ethylenediamine is added with stirring (molar ratio of carboxyl groups of PT to ethylenediamine: 1:50). The pH is adjusted to 5 using 0.2 M HCl. An aqueous solution of 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide (EDC) is added to the PT solution (molar ratio of carboxyl groups of PT to EDC: 1:18). The mixture is mixed at room temperature for 24 hours. PT-NH2 is precipitated from ethanol and extracted with ethanol using a Soxhlet for 12 hours. [ka]

[0161] In the third step, aminated pectin is added along with ionic pendants using the procedure of Example 1. [ka] Example 6: Chitosan-trialkylphosphonium bromide salt (hypothetical)

[0162] Bromoalkylphosphonium synthesis (R can be alkyl or benzyl)

[0163] First step - A trialkylphosphine is dissolved in acetonitrile in a round-bottom flask equipped with a stir bar. Dibromoethane dissolved in acetonitrile is added dropwise to the stirred solution. The resulting solution is heated at 65°C for 48 hours and then concentrated in vacuo. The material is purified using column chromatography (silica, DCM / MeOH). [ka]

[0164] Second step - chitosan modification: as in Example 1. [ka] Example 7: Dextran-trialkylphosphonium bromide salt (hypothetical)

[0165] Same as Example 2 (R can be alkyl or benzyl). [ka] Example 8: Dextran-imidazolium chloride salt (hypothetical) [ka]

[0166] The reaction is the same as in Example 3. Example 9: Pectin-Ethylenediaminetriphenylphosphonium Bromide Salt (hypothetical)

[0167] Synthesis of Aminophosphonium (R can be alkyl or benzyl)

[0168] First step: The alkylphosphine is dissolved in acetonitrile and 2-aminoethyl bromide is added. The reaction mixture is reacted at 25°C for 1.5 hours, followed by stirring under reflux for 20 hours. The temperature is reduced to 25°C, and the solvent is removed by evaporation under reduced pressure at 60°C. The resulting residue is dissolved in water, and the pH is adjusted to 11 by adding a saturated aqueous solution of Na2CO3. The aqueous system is extracted with dichloromethane. The combined organic phases are dried over MgSO4 and, after removing the drying agent, concentrated and dried. Further purification is carried out by column chromatography. [ka]

[0169] The second step is the same as in Example 5. [ka] Example 10: Chitosan-ethyleneguanidinium bromide salt (hypothetical)

[0170] First step - preparation of guanidine - dry 1,2-dichloroethane and tetramethylurea are placed in a two-neck flask. Oxalyl chloride is added at room temperature and the solution is heated at 60°C for 2 hours. The solvent is removed under vacuum and the remaining yellow solid is dissolved in 20 mL of dry ethanol. A 33% by weight solution of methylamine in dry ethanol is added dropwise at 0°C. The reaction mixture is slowly warmed to room temperature and stirred overnight, after which it is refluxed for 4 hours. The solvent is evaporated under vacuum and the residue is treated with 30% aqueous NaOH. The organic layer is extracted with ether and dried over anhydrous magnesium sulfate. The solvent is then evaporated. The final product is distilled under reduced pressure at 100°C. [ka]

[0171] Second step - same as first step of Example 6. [ka]

[0172] Third step - same as in Example 1. [ka] Example 11: Dextran-ethyleneguanidinium bromide salt (hypothetical)

[0173] Same as Example 2. [ka] Example 12: Chitosan-Triazolium Iodide Salt (hypothetical)

[0174] First Step - Alkyl triazolium salt: 1H-1,2,3-triazole-1-ethanol is dissolved in acetonitrile. A solution of methyl iodide in acetonitrile is added dropwise. The reaction is heated to 70°C for 30 hours with continuous stirring. The reaction mixture is then washed with ether and dried in a vacuum oven at room temperature. [ka]

[0175] Second stage - as in Example 3. [ka]

[0176] Third step - same as in Example 3. [ka] Example 13: Dextran-triazolium iodide salt (hypothetical)

[0177] Same as Example 3. [ka] Example 14: Chitosan-guanidinium-triazolium salt (hypothetical)

[0178] First step - guanidinium-triazolium salts: as in Example 6. [ka]

[0179] Second step - chitosan modification: as in Example 3. [ka]

[0180] Similarly, other ion pairs can be synthesized. Example 15: Dextran-phosphonium-triazolium iodide salt (hypothetical)

[0181] First step - as in Example 6. [ka]

[0182] 2nd step - As in Example 10 (using bromoethyl alkyl phosphonium salt instead of methyl iodide). [ka]

[0183] Third step - Dextran modification: As in Example 2. [ka]

[0184] Similarly, other ion pairs can be synthesized. Example 16: Chitosan-Trialkylphosphonium / Triphenylphosphonium Mixed Bromide (hypothetical)

[0185] Same as Example 1 (R can be 1≦n≦6). [ka] Example 17: Dextran-trialkylphosphonium / triphenylphosphonium mixed bromide (hypothetical)

[0186] Same as Example 2 (R can be 1≦n≦6). [ka]

[0187] Similarly, other ion mixtures can be synthesized. Part II CMP Experiments Part I: Using the synthesized cation-modified water-soluble polysaccharides

[0188] The polishing compositions and associated methods described herein are effective for CMP of a wide variety of substrates, including most substrates, and are particularly useful for polishing tungsten substrates.

[0189] In the examples below, CMP experiments were performed using the procedures and experimental conditions set out below. Parameters: Å: Angstrom - unit of length BP: Back pressure, unit is psi CMP: Chemical mechanical planarization = chemical mechanical polishing CS: Carrier Speed DF: Downforce: Pressure applied during CMP, unit is psi min:minutes mL: milliliter mV: millivolt psi: pounds per square inch PS: Polishing tool platen rotation speed, in rpm (revolutions per minute) SF: flow rate of polishing composition, mL / min Chemical vapor deposition using TEOS: tetraethyl orthosilicate as a precursor. (CVD) silicon oxide film Wt%: Weight percentage (of listed ingredient) Removal rate (RR) = (film thickness before polishing - film thickness after polishing) / polishing time. Removal rate and selectivity Tungsten removal rate: Tungsten removal rate measured at 2.5 psi down pressure on the CMP tool. TEOS removal rate: TEOS removal rate measured at a given down pressure. The down pressure of the CMP tool was 2.5 or 3 psi. SiN removal rate: SiN removal rate measured at a given down pressure. The down pressure of the CMP tool was 2.5 or 3 psi.

[0190] The CMP tool used in the examples was an AMAT 200 mm Mirra® manufactured by Applied Materials, Inc. 3050 Bowers Avenue, Santa Clara, California, 95054. An IC1010 polishing pad supplied by Dow Chemicals was used on the platen for the polishing tests.

[0191] 200 mm diameter silicon wafers coated with tungsten, TEOS, SiN, or tungsten-containing SKW patterned structures were obtained from SKW Associate, Inc., 2920 Scott Blvd., Santa Clara, CA 95054. The polishing time for blanket films was 1 minute. Sheet resistance measurement techniques were used to measure tungsten removal rates. Optical techniques were used to measure TEOS removal. The patterned wafers were polished on an Ebara polisher for a predetermined time based on eddy current technology. The polishing time for patterned wafers was 15 seconds past the endpoint identified by eddy current endpoint technology. The patterned wafers were analyzed with a KLA Tencor P15 Profiler (large feature size) or an AFM tool (small feature size).

[0192] Polishing was carried out using a table speed of 111 RPM, a carrier speed of 113 RPM, a slurry flow rate of 200 mL / min, and a downforce of 2.5 psi.

[0193] In the polishing process, a substrate (e.g., a blanket W or patterned W wafer) was placed face down on a polishing pad fixedly mounted on the rotatable platen of a CMP polisher. In this way, the substrate to be polished and planarized was placed in direct contact with the polishing pad. A wafer carrier system or polishing head was used to hold the substrate in a fixed position and apply downward pressure against the backside of the substrate during the CMP process, rotating the platen and substrate. A polishing composition (slurry) was applied (usually continuously) onto the pad during the CMP process to effectively remove material and planarize the substrate.

[0194] In the following examples, a CMP base slurry was prepared containing 0.01 wt % ferric nitrate (iron(III) nitrate), 0.08 wt % malonic acid (a stabilizer), 2.0 wt % hydrogen peroxide, 0.1 wt % glycine, and 0.25 wt % surface-modified silica particles in water whose pH was adjusted to 2.3 with nitric acid.

[0195] The surface-modified silica particles used in Tables 1 and 2 had an average primary particle size (d1) of 69.77 nm and an average secondary particle size (d2) of 89.7 nm, as measured using DLS analysis (dynamic light scattering). The surface-modified silica particles are disclosed in U.S. Provisional Patent Application No. 63 / 269,585, filed 03 / 18 / 2022, which is incorporated herein by reference in its entirety.

[0196] The surface-modified silica particles used in Tables 3-7 were Fuso PL-2C manufactured by Fuso Chemical Co., Ltd., which had an average primary particle size (d1) of approximately 20 nm and an average secondary particle size (d2) of approximately 40 nm, as measured using DLS analysis (dynamic light scattering).

[0197] Various amounts of the cation-modified water-soluble polysaccharides synthesized in Examples 1 and 3 were added to the base slurry as shown in Table 1.

[0198] The effect of cation-modified water-soluble polysaccharides on the removal rates of tungsten, TEOS, and SiN, as well as on W dishing (50 × 50 μm) and erosion (7 × 3 μm) on patterned wafers, was tested using a slurry containing in-house silica particles. The results are summarized in Table 2. [Table 1] [Table 2]

[0199] As shown in Table 1 , surprisingly, the CMP slurry using cation-modified water-soluble polysaccharides increased the RR of W while suppressing the RR of TEOS, thus significantly increasing the removal selectivity of W:TEOS.

[0200] As shown in Table 2, the CMP slurry using the cation-modified water-soluble polysaccharide significantly reduced W dishing.

[0201] The effect of the concentration of chitosan-triphenylphosphonium bromide salt (polymer additive of Example 1) on the TEOS film removal rate was tested, and the results are listed in Table 3. [Table 3]

[0202] As shown in Table 3, when chitosan-triphenylphosphonium bromide salt was used at 10 ppm or 50 ppm, the W film removal rate increased by 38% and 34%, respectively. When used at a concentration of 100 ppm, the W film removal rate decreased by about 10%.

[0203] The effects of the cation-modified water-soluble polysaccharide on the removal rate of tungsten TEOS and SiN, and on W dishing (50 × 50 μm) and erosion (7 × 3 μm) on patterned wafers were tested, and the results are summarized in Tables 4 and 5. [Table 4] [Table 5]

[0204] As shown in Table 4, the CMP slurries using cation-modified water-soluble polysaccharides maintained the removal selectivity of W RR, TEOS RR, or W:TEOS.

[0205] As shown in Table 5, the CMP slurry using the cation-modified water-soluble polysaccharide significantly reduced W dishing. Erosion was also improved.

[0206] The cationic polymer additive of Example 3 was also tested at two concentrations, 15 ppm and 30 ppm, respectively.

[0207] The results for tungsten TEOS and SiN removal rates, W dishing (50×50 μm), and erosion (7×3 μm) on patterned wafers are summarized in Tables 6 and 7. [Table 6]

[0208] Similar to the data shown in Table 4, CMP slurries using cation-modified water-soluble polysaccharides maintained removal selectivity for W RR, TEOS RR, or W:TEOS. [Table 7]

[0209] Similar to the data shown in Table 5, the CMP slurry using the cation-modified water-soluble polysaccharide significantly reduced W dishing. Erosion was also improved.

[0210] While the principles of the present invention have been described above in connection with preferred embodiments, it is to be clearly understood that this description is made by way of example only and is not intended to limit the scope of the invention. Rather, the detailed description of the preferred exemplary embodiments will provide those skilled in the art with an enabling description for practicing the preferred exemplary embodiments of the invention. Various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention, as set forth in the appended claims.

Claims

1. A cation-modified water-soluble polysaccharide, 【Chemistry 1】 [In the formula, The water-soluble polysaccharides were selected from the group consisting of chitosan, pectin, dextran, pullulan, and inulin. The pentagon or hexagon represents the skeleton of a water-soluble polysaccharide. Z is NH, -O-, -S-, -O-(C=O)-, -NH-(C=O)-, -O-(C=O)-, -NH-(C=O)-, NR' (R' is C １ ~C ６ It is an alkyl having a carbon-carbon double bond or triple bond as shown below, 【Chemistry 2】 The two carbon atoms in the double bond structure are two protons, one proton, and one alkyl group R'' (where R'' is C). １ ~C ６ (an alkyl having C) two identical alkyl groups R'', or two different alkyl groups R'' and R'''' (R'''' is C １ ~C ６ It can be connected to an alkyl having Sp indicates the presence of a spacer group having a single or double bond structure at each occurrence. Y ＋ represents N ＋ , P ＋ , and S ＋ represents a cationic functional group selected from the group consisting of, said cationically modified water-soluble polysaccharide comprises a repeating unit that contains no ions or contains at least one ion, X － is F － , Cl － , Br － , I － BF ４ － CF ３ BF ３ － , OH － PF ６ － Carboxylate, malonate, citrate, carbonate, fumarate, MeOSO ３ － MeSO ３ － (Me is methyl), CF ３ COO － CF ３ SO ３ － This represents a counterion selected from the group consisting of cyanates, isothiocyanates, nitrates, phosphates, and sulfates. R is H; CH ３ (R) represents a cationic side group selected from the group consisting of saturated or unsaturated, branched or aliphatic alkyl chains; cyclic rings; and other functional groups selected from the group consisting of amines, carboxylic acids, sulfonates, siloxanes, ethers, and alcohols. ３ It may form a ring selected from the group consisting of imidazolium, triazolium, and tetrazolium, tris-alkylphosphonium, tris-phenylphosphonium, tris-alkylsulfonium, and tris-phenylsulfonium, or it may be alkyl. A cationically modified water-soluble polysaccharide comprising cationic repeating units having a structure selected from the group consisting of n representing the number of repeating units, where 1 < n < 2000.

2. The cation-modified water-soluble polysaccharide according to claim 1, wherein the water-soluble polysaccharide is modified by a method selected from the group consisting of etherification, esterification, amidation, and amination, and has an ion density of 5 to 200%.

3. The aforementioned cation-modified water-soluble polysaccharides are chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, A cation-modified water-soluble polysaccharide according to claim 1, selected from the group consisting of dextran-imidazolium chloride salt, dextran-ethyleneguanidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof.

4. A chemical mechanical planarization composition comprising 0.00001% to 1.0% by weight of the cation-modified water-soluble polysaccharide described in Claim 1, wherein the cation-modified water-soluble polysaccharide has an ion density of 5 to 200%.

5. Abrasives, Activator, Oxidizing agent, Corrosion inhibitors, Dishing reducing agent, Stabilizers, pH adjuster, The chemical mechanical planarization composition according to claim 4, further comprising at least one of the following.

6. The chemical mechanical planarization composition according to claim 5, wherein the abrasive is selected from the group consisting of inorganic oxide particles, metal oxide coated inorganic oxide particles, organic polymer particles, metal oxide coated organic polymer particles, and combinations thereof, and the abrasive is in the range of 0.01% to 30% by weight.

7. The cation-modified water-soluble polysaccharide is: chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt A chemical mechanical planarization composition according to claim 5, selected from the group consisting of dextran-imidazolium chloride salt, dextran-ethyleneguanidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof.

8. The activator is selected from the group consisting of: (1) inorganic oxide particles coated on their surface with a transition metal, wherein the transition metal is selected from the group consisting of Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) a soluble catalyst selected from the group consisting of iron(III) nitrate, iron(III) ammonium oxalate trihydrate, tribasic iron(III) citrate monohydrate, iron(III) acetylacetonate and ethylenediaminetetraacetic acid, and iron(III) sodium salt hydrate; and (3) a metal compound having multiple oxidation states selected from the group consisting of Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, and V, and combinations thereof. The oxidizing agent is selected from the group consisting of peroxy compounds selected from the group consisting of hydrogen peroxide, urea peroxide, peroxyformic acid, peracetic acid, propane peroxoacid, substituted or unsubstituted butane peroxoacid, hydroperoxyacetaldehyde, potassium periodate, and ammonium peroxymonosulfate, as well as non-peroxy compounds selected from the group consisting of ferric nitrite, KClO₄, KBrO₄, and KMnO₄, and combinations thereof. The corrosion inhibitor is selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, 1,2,3-benzotriazole, 5-methylbenzotriazole, benzotriazole, 1-hydroxybenzotriazole, 4-hydroxybenzotriazole, 3-amino-1,2,4-triazole, 4-amino-4H-1,2,4-triazole, 5-aminotriazole, benzimidazole, 2,1,3-benzothiadiazole, triazinethiol, triazinedithiol, and triazinetrithiol, pyrazole, imidazole, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof. The dishing reducing agent is selected from the group consisting of sarcosinates and related carboxylic acid compounds, hydrocarbon-substituted sarcosinates, amino acids, organic polymers and copolymers having molecules containing ethylene oxide repeating units, ethoxylated surfactants, nitrogen-containing heterocycles that do not contain nitrogen-hydrogen bonds, sulfides, oxazolidines, or mixtures of functional groups in one compound, nitrogen-containing compounds having three or more carbon atoms that form alkylammonium ions, aminoalkyls having three or more carbon atoms, polymer corrosion inhibitors containing at least one nitrogen-containing heterocycle or repeating group of tertiary or quaternary nitrogen atoms, polycationic amine compounds, cyclodextrin compounds, polyethyleneimine compounds, glycolic acid, chitosan, sugar alcohols, polysaccharides, alginate compounds, and sulfonic acid polymers, and combinations thereof. The stabilizer is selected from the group consisting of adipic acid, phthalic acid, citric acid, malonic acid, orthophthalic acid, phosphoric acid, substituted or unsubstituted phosphonic acid, nitrile, and combinations thereof, and The pH adjusting agent is selected from the group consisting of (a) nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids, and mixtures thereof for lowering pH, and (b) potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof for raising pH. The chemical mechanical planarizing composition according to claim 5.

9. The chemical mechanical planarization composition comprises silica particles or surface-modified silica particles, and the cation-modified water-soluble polysaccharide is chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, dextran A chemical mechanical planarization composition according to claim 5, selected from the group consisting of trans-imidazolium chloride salt, dextran-ethyleneguanidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof, iron(III) nitrate, malonic acid, hydrogen peroxide, and water, wherein the pH of the composition is 1 to 14.

10. A polishing method for chemical planarization of a semiconductor substrate having at least one surface containing tungsten, a) A process of providing a polishing pad, b) A step of providing a chemical mechanical planarization composition, wherein the chemical mechanical planarization composition is Abrasives, An additive comprising 0.00001% to 1.0% by weight of the cation-modified water-soluble polysaccharide described in claim 1, Water, and optionally, Activator, Oxidizing agent, Corrosion inhibitors, Dishing reducing agent, Stabilizers, pH adjuster It includes at least one of the following: The cation-modified water-soluble polysaccharide has an ion density of 5 to 200%. A step of providing a chemical mechanical planarization composition, c) A polishing method comprising the step of polishing at least one surface containing tungsten with the chemical mechanical planarization composition.

11. The polishing method according to claim 10, wherein the chemical mechanical planarization composition comprises an abrasive selected from the group consisting of inorganic oxide particles, metal oxide coated inorganic oxide particles, organic polymer particles, metal oxide coated organic polymer particles, and combinations thereof, and the abrasive is in the range of 0.01% to 30% by weight.

12. The additive is chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, dextran-imidazolium bromide salt The polishing method according to claim 10, comprising a cation-modified water-soluble polysaccharide selected from the group consisting of dazolium chloride salt, dextran-ethyleneguanidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof.

13. The activator is selected from the group consisting of: (1) inorganic oxide particles coated on their surface with a transition metal, wherein the transition metal is selected from the group consisting of Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) a soluble catalyst selected from the group consisting of iron(III) nitrate, iron(III) ammonium oxalate trihydrate, tribasic iron(III) citrate monohydrate, iron(III) acetylacetonate and ethylenediaminetetraacetic acid, and iron(III) sodium salt hydrate; and (3) a metal compound having multiple oxidation states selected from the group consisting of Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, and V, and combinations thereof. The oxidizing agent is selected from the group consisting of peroxy compounds selected from the group consisting of hydrogen peroxide, urea peroxide, peroxyformic acid, peracetic acid, propane peroxoacid, substituted or unsubstituted butane peroxoacid, hydroperoxyacetaldehyde, potassium periodate, and ammonium peroxymonosulfate, as well as non-peroxy compounds selected from the group consisting of ferric nitrite, KClO₄, KBrO₄, and KMnO₄, and combinations thereof. The corrosion inhibitor is selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, 1,2,3-benzotriazole, 5-methylbenzotriazole, benzotriazole, 1-hydroxybenzotriazole, 4-hydroxybenzotriazole, 3-amino-1,2,4-triazole, 4-amino-4H-1,2,4-triazole, 5-aminotriazole, benzimidazole, 2,1,3-benzothiadiazole, triazinethiol, triazinedithiol, and triazinetrithiol, pyrazole, imidazole, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof. The dishing reducing agent is selected from the group consisting of sarcosinates and related carboxylic acid compounds, hydrocarbon-substituted sarcosinates, amino acids, organic polymers and copolymers having molecules containing ethylene oxide repeating units, ethoxylated surfactants, nitrogen-containing heterocycles that do not contain nitrogen-hydrogen bonds, sulfides, oxazolidines, or mixtures of functional groups in one compound, nitrogen-containing compounds having three or more carbon atoms that form alkylammonium ions, aminoalkyls having three or more carbon atoms, polymer corrosion inhibitors containing at least one nitrogen-containing heterocycle or repeating group of tertiary or quaternary nitrogen atoms, polycationic amine compounds, cyclodextrin compounds, polyethyleneimine compounds, glycolic acid, chitosan, sugar alcohols, polysaccharides, alginate compounds, and sulfonic acid polymers, and combinations thereof. The stabilizer is selected from the group consisting of adipic acid, phthalic acid, citric acid, malonic acid, orthophthalic acid, phosphoric acid, substituted or unsubstituted phosphonic acid, nitrile, and combinations thereof, and The pH adjusting agent is selected from the group consisting of (a) nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids, and mixtures thereof for lowering pH, and (b) potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof for raising pH. The polishing method according to any one of claims 10 to 12.

14. The chemical mechanical planarization composition comprises silica particles or surface-modified silica particles, and the cation-modified water-soluble polysaccharide is chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, dextran-imidazolium chloride salt, dextran-ethyleneguanidinium bromide salt The polishing method according to claim 10, wherein the composition is selected from the group consisting of nidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof, iron(III) nitrate, malonic acid, hydrogen peroxide, poly(vinyl-3-ethyl-1H-imidazole-3-ium-co-tributyl-(4-vinylbenzyl)-phosphonium) bromide chloride, and water, and the pH of the composition is 1 to 7.

15. A system for chemical planarization of a semiconductor substrate having at least one surface containing tungsten, a) Polishing pad and b) Abrasives, An additive comprising 0.00001% to 1.0% by weight of the cation-modified water-soluble polysaccharide described in claim 1, Water, and optionally Activator, Oxidizing agent, Corrosion inhibitors, Dishing reducing agent, Stabilizers, pH adjuster A chemical mechanical planarization composition comprising at least one of the following, The cation-modified water-soluble polysaccharide has an ion density of 5 to 200%, and A system in which at least one surface containing tungsten is in contact with the polishing pad and the chemical mechanical planarization composition, thereby polishing the at least one surface containing tungsten with the chemical mechanical planarization composition.

16. The system according to claim 15, wherein the chemical mechanical planarization composition comprises an abrasive selected from the group consisting of inorganic oxide particles, metal oxide coated inorganic oxide particles, organic polymer particles, metal oxide coated organic polymer particles, and combinations thereof, and the abrasive is in the range of 0.01% to 30% by weight.

17. The additive is chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, dextran-imidazolium bromide salt The system according to claim 15, comprising a cation-modified water-soluble polysaccharide selected from the group consisting of dazolium chloride salt, dextran-ethyleneguanidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof.

18. The activator is selected from the group consisting of: (1) inorganic oxide particles coated on their surface with a transition metal, wherein the transition metal is selected from the group consisting of Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) a soluble catalyst selected from the group consisting of iron(III) nitrate, iron(III) ammonium oxalate trihydrate, tribasic iron(III) citrate monohydrate, iron(III) acetylacetonate and ethylenediaminetetraacetic acid, and iron(III) sodium salt hydrate; and (3) a metal compound having multiple oxidation states selected from the group consisting of Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, and V, and combinations thereof. The oxidizing agent is selected from the group consisting of peroxy compounds selected from the group consisting of hydrogen peroxide, urea peroxide, peroxyformic acid, peracetic acid, propane peroxoacid, substituted or unsubstituted butane peroxoacid, hydroperoxyacetaldehyde, potassium periodate, and ammonium peroxymonosulfate, as well as non-peroxy compounds selected from the group consisting of ferric nitrite, KClO₄, KBrO₄, and KMnO₄, and combinations thereof. The corrosion inhibitor is selected from the group consisting of 1,2,3-triazole, 1,2,4-triazole, 1,2,3-benzotriazole, 5-methylbenzotriazole, benzotriazole, 1-hydroxybenzotriazole, 4-hydroxybenzotriazole, 3-amino-1,2,4-triazole, 4-amino-4H-1,2,4-triazole, 5-aminotriazole, benzimidazole, 2,1,3-benzothiadiazole, triazinethiol, triazinedithiol, and triazinetrithiol, pyrazole, imidazole, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof. The dishing reducing agent is selected from the group consisting of sarcosinates and related carboxylic acid compounds, hydrocarbon-substituted sarcosinates, amino acids, organic polymers and copolymers having molecules containing ethylene oxide repeating units, ethoxylated surfactants, nitrogen-containing heterocycles that do not contain nitrogen-hydrogen bonds, sulfides, oxazolidines, or mixtures of functional groups in one compound, nitrogen-containing compounds having three or more carbon atoms that form alkylammonium ions, aminoalkyls having three or more carbon atoms, polymer corrosion inhibitors containing at least one nitrogen-containing heterocycle or repeating group of tertiary or quaternary nitrogen atoms, polycationic amine compounds, cyclodextrin compounds, polyethyleneimine compounds, glycolic acid, chitosan, sugar alcohols, polysaccharides, alginate compounds, and sulfonic acid polymers, and combinations thereof. The stabilizer is selected from the group consisting of adipic acid, phthalic acid, citric acid, malonic acid, orthophthalic acid, phosphoric acid, substituted or unsubstituted phosphonic acid, nitrile, and combinations thereof, and The pH adjusting agent is selected from the group consisting of (a) nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids, and mixtures thereof for lowering pH, and (b) potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof for raising pH. The system according to claim 15.

19. The chemical mechanical planarization composition comprises silica particles or surface-modified silica particles, and the cation-modified water-soluble polysaccharide is chitosan-triphenylphosphonium bromide salt, dextran-triphenylphosphonium bromide salt, chitosan-imidazolium chloride salt, dextran-(2-hydroxy)propyltriphenylphosphonium chloride salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-trialkylphosphonium bromide salt, dextran-trialkylphosphonium bromide salt, pectin-ethylenediaminetriphenylphosphonium bromide salt, chitosan-ethyleneguanidinium bromide salt, dextran-imidazolium chloride salt, dextran-ethyleneguanidinium bromide salt The system according to claim 15, wherein a composition is selected from the group consisting of nidinium bromide salt, chitosan-triazolium iodide salt, dextran-triazolium iodide salt, chitosan-guanidinium-triazolium salt, dextran-phosphonium-triazolium iodide salt, chitosan-trialkylphosphonium / triphenylphosphonium mixed bromide, dextran-trialkylphosphonium / triphenylphosphonium mixed bromide, and combinations thereof, iron(III) nitrate, malonic acid, hydrogen peroxide, poly(vinyl-3-ethyl-1H-imidazole-3-ium-co-tributyl-(4-vinylbenzyl)-phosphonium) bromide chloride, and water, and the pH of the composition is 1 to 7.

20. The polishing method according to claim 14, wherein the pH of the composition is 1.5 to 4.

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