Dicationic polymers or copolymers and their use for chemical mechanical planarization

Abstract

Synthesis of dicationic polymers or copolymers is disclosed. The dicationic polymer or copolymer is formed from at least one dicationic (or dicationic) monomer. A chemical mechanical planarization (CMP) slurry includes an abrasive; an activator; an oxidant; an additive comprising a dicationic polymer or copolymer; and water. The use of synthetic dicationic polymers or copolymers in CMP slurries reduces sagging and erosion in high selectivity tungsten slurries.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 387,137, filed December 13, 2022, which is incorporated herein by reference as if not set forth in its entirety. Background Art

[0003] The present disclosure relates to chemical mechanical planarization or polishing ("CMP") slurries (or compositions or formulations), polishing methods, and polishing systems for chemical mechanical planarization in the production of semiconductor devices. In particular, the present disclosure relates to polishing slurries suitable for polishing patterned semiconductor wafers including tungsten-containing metal materials.

[0004] Chemical mechanical polishing or planarization (CMP) has been successfully used in the manufacturing process of integrated circuits for decades. It is considered a key and enabling technology for the demand for miniaturization.

[0005] Integrated circuits are interconnected using well-known multi-layer interconnects. The interconnect structure typically has a first metallization layer, an interconnect layer, a second metallization layer, and typically a third and subsequent metallization layers. Interlayer dielectric materials such as silicon dioxide and sometimes low-k materials are used to electrically isolate different metallization layers in a silicon substrate or well. Electrical connections between different interconnect layers are formed using metallized vias, particularly tungsten vias. U.S. Patent No. 4,789,648 describes a method for preparing multiple metallization layers and metallized vias in an insulating film. In a similar manner, metal contacts are used to form electrical connections between devices formed in the interconnect layers and wells. The metal vias and contacts are typically filled with tungsten, and an adhesion layer such as titanium nitride (TiN) and / or titanium is typically used to adhere the metal layer (such as the tungsten metal layer) to the dielectric material.

[0006] 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 is etched through the interlayer dielectric (ILD) to the interconnect or semiconductor substrate. Next, a thin adhesion layer, such as titanium nitride and / or titanium, is typically formed over the ILD and directed into the etched via. A tungsten film is then blanket deposited over the adhesion layer and into the via. Deposition continues until the via is filled with tungsten. Finally, CMP is performed to remove the excess tungsten to form the metal via.

[0007] In another semiconductor manufacturing process, tungsten is used as the gate electrode material in transistors because its electrical properties are superior to polysilicon, which is traditionally used as the gate electrode material, as taught in A. Yagishita et al., IEEE TRANSACTIONS ON ELECTRON DEVICES, Vol. 47, No. 5, May 2000.

[0008] In a typical CMP process, a substrate comes into direct contact with a rotating polishing pad. A carrier applies pressure to the backside of the substrate. During polishing, the polishing pad and platen rotate while maintaining a downward force on the backside of the substrate. During polishing, an abrasive and chemically reactive solution, often referred to as a polishing "slurry," polishing "composition," or polishing "formulation," is deposited onto the pad, where the rotation and / or movement of the pad relative to the wafer carries 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. As the slurry is supplied to the wafer / polishing pad interface, the polishing process is facilitated by the rotational motion of the pad relative to the substrate. Polishing continues in this manner until the desired film on the insulator is removed. Tungsten removal in CMP is believed to be due to a synergy between mechanical wear and tungsten oxidation and subsequent dissolution.

[0009] Despite its relatively simple outward 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 10.1002 / 3527600434.eap847; and most of the time, CMP technology evolves faster than Seo, J described in Journal of Materials Research 2021, 36(1), 235.1 based on his understanding.

[0010] Its importance as a technology for achieving past and future device scaling requirements and emerging trends in the semiconductor industry is undisputed. Numerous interactions between the wafer, slurry, and pad, as well as general process parameters, determine the outcome of CMP. Ultimately, 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. A vast array of materials are used in semiconductor device manufacturing, all of which require optimized CMP processes. Simultaneously polishing a combination of disparate materials, such as dielectric materials, barrier layers, and metal layers, presents a real challenge for CMP.

[0011] One of the common problems encountered in CMP, especially in metal applications such as tungsten, is how to control topographic defects such as erosion and dishing. Smaller feature sizes and devices at the 7nm node and above place even stricter requirements on acceptable defect levels during polishing.

[0012] Highly selective slurries (which have a large difference between metal removal rates and dielectric removal rates) are of great significance for future industry needs. However, there are also drawbacks associated with the use of these highly selective slurries. The metal layer can easily be over-polished, resulting in a "dimpling" effect. Another unacceptable defect is called "erosion," which describes the difference in topography between areas with dielectrics and dense arrays of metal vias or trenches.

[0013] Specially designed water-based slurries are considered a major driver for improving CMP performance for future devices. Slurry development not only influences removal rates and selectivity between different layers, but also controls defects during the polishing process. Generally speaking, slurry compositions are complex combinations of abrasives and chemical components with different functionalities. Polymer additives, acting as dispersants, passivators, or generally as topography control additives, play a key role in slurry development to achieve the desired removal rates, selectivity, and minimize surface defects by interacting with certain materials. For example, positively charged polymers inhibit tungsten removal and can be used to reduce dishing during tungsten CMP.

[0014] US 5,876,490 describes the use of a polishing slurry comprising abrasive particles and exhibiting a normal stress effect, and further comprising a polyelectrolyte having an ionic portion having a charge different from the charge associated with the abrasive particles, wherein the concentration of the polyelectrolyte is from about 5 to about 50 weight percent of the abrasive particles, and wherein the molecular weight of the polyelectrolyte is from about 500 to about 10,000.

[0015] US6776810 describes a chemical-mechanical polishing system and a method of polishing a substrate using the polishing system, the system comprising (a) an abrasive, (b) a liquid carrier, and (c) a positively charged polyelectrolyte having a molecular weight of about 15,000 or greater, wherein the abrasive comprises particles electrostatically associated with the positively charged electrolyte.

[0016] US Pat. No. 7,247,567 provides a method for chemically-mechanically polishing a tungsten-containing substrate using a composition comprising a tungsten etchant, a tungsten etch inhibitor, and water, wherein the tungsten polish inhibitor is a polymer, copolymer, or polymer blend comprising at least one repeating group containing at least one nitrogen-containing heterocycle or a tertiary or quaternary nitrogen atom. The present invention also provides a chemical-mechanical polishing composition particularly useful for polishing tungsten-containing substrates.

[0017] US2010075501A1 describes a chemical mechanical polishing aqueous dispersion for polishing a polishing target including a tungsten-containing interconnect layer. The chemical mechanical polishing aqueous dispersion comprises: (A) a cationic water-soluble polymer; (B) an iron (III) compound; and (C) colloidal silica particles. The content (M) of the cationic water-soluble polymer (A) is A ) (mass %) and the content of the iron (III) compound (B) (M B (mass %) satisfies the relationship "M A / M B =0.004 to 0.1". The pH of the chemical mechanical polishing aqueous dispersion is 1 to 3.

[0018] US2010 / 0252774 A1 describes a chemical mechanical polishing aqueous dispersion for polishing a polishing target including a tungsten-containing wiring layer. The chemical mechanical polishing aqueous dispersion comprises: (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 a specific surface area measured by the BET method. The content (M) of the cationic water-soluble polymer (A) is A ) (mass %) and the content of colloidal silica (C) (M C (mass %) satisfies the relationship "M A / M C =0.0001 to 0.003". The chemical mechanical polishing aqueous dispersion.

[0019] US Pat. No. 10,604,678 B1 discloses a method and composition for polishing tungsten, comprising a low concentration of a quaternary phosphonium compound selected to at least reduce the corrosion rate of the tungsten. The method and composition comprise providing a tungsten-containing substrate, providing a stable polishing composition comprising, as initial components: water, an oxidizing agent; a low concentration of a quaternary phosphonium compound selected to at least reduce the corrosion rate; a dicarboxylic acid; a source of iron ions; a colloidal silica abrasive; and optionally, a pH adjuster; providing a chemical mechanical polishing pad having a polishing surface; establishing dynamic contact at an interface between the polishing pad and the substrate; and dispensing the polishing composition onto the polishing surface at or near the interface between the polishing pad and the substrate; wherein some tungsten is polished away from the substrate and the corrosion rate of the tungsten is reduced.

[0020] US 2009 / 0081871 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 that have been treated with an aminosilane compound.

[0021] US2014 / 0248823 describes a chemical-mechanical polishing composition comprising (a) abrasive particles, (b) a polymer, and (c) water, wherein (i) the polymer has an overall charge, (ii) the abrasive particles have a zeta potential Za measured in the absence of the polymer, and the abrasive particles have a zeta potential Zb measured in the presence of the polymer, wherein the zeta potential Za is a value of the same sign as the overall charge of the polymer, and (iii) the Izeta potential Z bI >Izeta potential Z aI The invention also provides a method for polishing a substrate using the polishing composition.

[0022] WO9905706 describes chemical mechanical polishing compositions and slurries comprising a composition capable of etching tungsten and at least one tungsten etching inhibitor, and methods of polishing tungsten-containing substrates using the compositions and slurries.

[0023] US20150259573 describes a chemical mechanical polishing composition for polishing a substrate having a tungsten layer, comprising an aqueous liquid carrier, a colloidal silica abrasive dispersed in the liquid carrier and having a permanent positive charge of at least 6 mV, and a polycationic amine compound in solution in the liquid carrier. The method for chemical mechanical polishing a substrate comprising a tungsten layer comprises contacting the substrate with the polishing composition, moving the polishing composition relative to the substrate, and grinding the substrate to remove a portion of the tungsten from the substrate, thereby polishing the substrate.

[0024] Imidazolium-type cationic polymers, phosphonium group-based polyionic liquids, and triazole- or triazolium-based polymers are identified and used in CMP slurries in WO2022 / 246381, WO2022 / 261614, and WO2023 / 056324, respectively; which are incorporated herein by reference in their entirety.

[0025] One of the common problems encountered in CMP, particularly in metal applications such as tungsten, is dishing of tungsten lines and erosion of metal line arrays. Dishevel and erosion are key CMP parameters that define the planarity of polished wafers. Line dishing typically increases with wider lines, while array erosion typically increases with increasing pattern density.

[0026] Tungsten CMP slurries must be formulated so that dishing and erosion can be minimized to meet certain design goals that are critical to functional devices.

[0027] Finding solutions to control topographic defects such as erosion and dishing is key to future CMP needs. There remains a need for novel tungsten CMP slurries that can reduce dishing and erosion while maintaining desired removal rates during polishing. Summary of the Invention

[0028] The present invention addresses this need by providing intelligently designed tungsten CMP slurries, systems, and methods of using the same to minimize the described dishing and erosion problems in highly selective tungsten slurries while maintaining the desired polish of metal layers, particularly tungsten films.

[0029] More specifically, the present invention discloses the synthesis of dicationic or dual cationic polymers or copolymers.

[0030] The dicationic polymer or copolymer is formed from at least one first dicationic monomer. CMP slurries using dicationic polymers have been shown to reduce dishing and erosion and provide high selectivity in removal rates of tungsten phase over TEOS or SiN.

[0031] Furthermore, several specific aspects of the present invention are summarized below.

[0032] Aspect 1: A dicationic polymer or copolymer formed from at least one dicationic monomer comprising the structure of (I) below;

[0033]

[0034] in:

[0035] P1 represents a polymerizable group;

[0036] Sp1 and Sp2 independently represent a spacer group or a single bond at each occurrence;

[0037] R1, R2 and R3 are each independently H or a substituted or unsubstituted aliphatic or aromatic moiety selected from (1) an alkyl group having <12 C atoms, <6 C atoms, <4 C atoms or <2 C atoms, preferably CH3 or CH2-CH3; (2) a phenyl group, a pyridyl group, a pyrimidyl group, a furanyl group or a nitrogen-containing five-membered ring; preferably a pyridyl group or a pyrimidinyl group; and (3) a combination of (1) and (2).

[0038] Cat represents a cationic group at each occurrence; preferably an ammonium-, guanidinium-, triazolium-, phosphonium-, pyridinium- or triazolium-type group.

[0039] X - represents anionic counter ions.

[0040] Aspect 2: A dicationic polymer or copolymer according to aspect 1, wherein the polymerizable group P1 is selected from groups containing a C=C double bond.

[0041] Aspect 3: A dicationic polymer or copolymer according to aspects 1-2, wherein the anionic counterion is selected from halide (F-, Cl-, Br-, I-), BF4-, PF6-, carboxylate, malonate, citrate, carbonate, fumarate, MeOSO3-, MeSO3-, CF3COO-, CF3SO3-, nitrate or sulfate.

[0042] Aspect 4: The dicationic polymer or copolymer according to aspects 1-3, wherein the dicationic polymer or copolymer is formed by a polymerization method selected from the group consisting of free radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), atom transfer polymerization (ATRP), ring-opening polymerization (ROMP) and condensation polymerization.

[0043] Aspect 5: The dicationic polymer or copolymer according to aspects 1 to 4, wherein the dicationic polymer or copolymer has block copolymer characteristics.

[0044] Aspect 6: A chemical mechanical planarization composition comprising the dicationic polymer or copolymer according to aspects 1-5.

[0045] Aspect 7: A chemical mechanical planarization composition comprising:

[0046] 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;

[0047] Activator;

[0048] oxidants;

[0049] The dicationic polymer or copolymer according to aspects 1-5;

[0050] water; and optionally

[0051] corrosion inhibitors;

[0052] sag reducers;

[0053] stabilizers;

[0054] pH adjuster.

[0055] Aspect 8: A system for chemical mechanical planarization, comprising:

[0056] a semiconductor substrate comprising at least one tungsten-containing surface;

[0057] polishing pads; and

[0058] The chemical mechanical planarization composition according to aspects 6-7;

[0059] Wherein the at least one tungsten-containing surface is in contact with a polishing pad and a chemical mechanical planarization composition.

[0060] Aspect 9: A polishing method for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten-containing surface, comprising the steps of:

[0061] a) contacting at least one tungsten-containing surface with a polishing pad;

[0062] b) delivering a chemical mechanical planarization composition according to aspects 6-7;

[0063] c) polishing the at least one tungsten-containing surface with a chemical mechanical planarization composition.

[0064] 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, and combinations thereof.

[0065] 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.

[0066] 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.

[0067] Organic polymer particles include, but are not limited to, polystyrene particles, polyurethane particles, polyacrylate particles, or any other organic polymer particles.

[0068] The metal oxide-coated organic polymer particles are selected from ceria-coated organic polymer particles and zirconia-coated organic polymer particles.

[0069] The concentration of the abrasive can be in the range of 0.01 wt % to 30 wt %, preferably about 0.05 wt % to about 20 wt %, more preferably about 0.01 to about 10 wt %, and most preferably 0.1 wt % to 2 wt %. The weight percentages are relative to the composition.

[0070] Activators include, but are not limited to (1) inorganic oxide particles coated with a transition metal on their surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce and combinations thereof; (2) a soluble catalyst selected from iron (III) nitrate, iron (III) ammonium oxalate trihydrate, iron (III) citrate monohydrate, iron (III) acetylacetonate and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate; (3) a metal compound with multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V; and combinations thereof.

[0071] The range of the activator is 0.00001 wt% to 5.0 wt%, 0.0001 wt% to 2.0 wt%, 0.0005 wt% to 1.0 wt%, or 0.001 wt% to 0.5 wt%.

[0072] Oxidizing agents include, but are not limited to, peroxy compounds selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted perbutyric acid, hydroperoxide-acetaldehyde, potassium periodate, ammonium peroxymonosulfate; and non-peroxy compounds selected from ferric nitrite, KClO4, KBrO4, KMnO4.

[0073] The oxidizing agent concentration may range from about 0.01 wt% to 30 wt%, with a preferred concentration of the oxidizing agent being from about 0.1 wt% to 20 wt%, and a more preferred concentration of the oxidizing agent being from about 0.5 wt% to about 10 wt%. The weight percentages are relative to the composition.

[0074] Examples of dicationic polymers or copolymers include, but are not limited to, poly(3-ethyl-1-(3-(1-vinyl-1H-imidazol-3-yl)propyl)-1H-imidazol-3-ium dibromide), poly(3-(tributylphosphino)propyl)-1-vinyl-1H-imidazol-3-ium dibromide), poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide), and poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium-co-N-vinyl-pyrrolidone dibromide).

[0075] Typical amounts of additives comprising dicationic polymers or copolymers range from 0.00001 wt% to 1 wt%, 0.0001 wt% to 0.5 wt%, 0.0005 wt% to 0.1 wt%, or 0.001 wt% to 0.06 wt%.

[0076] Suitable pH adjusting agents 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 adjusting agents 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.

[0077] The pH of the slurry is between 1 and 14, preferably between 1 and 7, more preferably between 1 and 6, and most preferably between 1.5 and 4.

[0078] The CMP slurry may further comprise a surfactant; a dispersant; a chelating agent; a film-forming anti-corrosion agent; and a biocide.

[0079] Other aspects, features and embodiments of the present invention will be more fully apparent from the ensuing disclosure and appended claims.

[0080] The embodiments of the present invention may be used alone or in combination with each other. DETAILED DESCRIPTION

[0081] The present invention addresses this need by providing intelligently designed tungsten CMP slurries, systems, and methods of using the same to reduce the described problems of dishing and erosion in highly selective slurries while maintaining the desired polish of metal layers, particularly tungsten films.

[0082] Specific water-soluble cationic polymers have been used in customized slurry formulations to reduce defects while achieving desired removal rates and selectivities.

[0083] The present invention extends the general application range of cationic polymers to dicationic polymers or copolymers. Surprisingly, dicationic polymers or copolymers show significantly better erosion and pitting inhibition while achieving the desired high removal rates and selectivities.

[0084] Among the polymers used in CMP slurries, the disclosed dicationic polymers or copolymers are surprisingly not described as additives for use in CMP slurries.

[0085] The present invention discloses the synthesis of dicationic polymers or copolymers and demonstrates the use of the synthesized dicationic polymers or copolymers in CMP slurries to reduce the dishing and erosion problems described in highly selective tungsten slurries.

[0086] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0087] In the context of describing the present invention (especially in the context of the appended claims), the use of the terms "one" and "an" and "the" and similar indicators should be interpreted as covering the singular and plural, unless otherwise stated herein or clearly contradictory to the context. Unless otherwise stated, the terms "comprise", "have", "include" and "contain" should be interpreted as open terms (that is, meaning "including, but not limited to"). Unless otherwise stated herein, the description of numerical ranges herein is only intended to be used as a shorthand method for individually referring to each individual value falling within the range, and each individual value is incorporated into the specification as if it were individually stated in this article. Unless otherwise stated herein or clearly contradictory to the context, all methods described herein can be performed in any appropriate order. The use of any and all examples or exemplary languages (e.g., "such as") provided herein is merely to better illustrate the present invention, rather than to limit the scope of the present invention, unless otherwise stated. Any language in the specification should not be interpreted as indicating that any unclaimed element is essential for the implementation of the present invention. Use of the term "comprising" in the specification and claims includes the narrower terms "consisting essentially of and "consisting of.

[0088] Embodiments are described herein, including the best mode known to the inventor for carrying out the present invention. After reading the foregoing description, variations of those embodiments may become apparent to those of ordinary skill in the art. The inventors expect that a skilled person will appropriately adopt these variations, and the inventors intend to implement the present invention in a manner different from that specifically described herein. Therefore, the present invention includes all modifications and equivalents of the subject matter described in the appended claims as permitted by applicable law. In addition, the present invention encompasses any combination of the above-mentioned elements in all possible variations, unless otherwise indicated herein or clearly contradicted by the context.

[0089] For ease of reference, "microelectronic device" corresponds to semiconductor substrates, flat panel displays, phase change memory devices, solar panels and other products, including solar substrates, photovoltaic devices and micro-electromechanical systems (MEMS), which are manufactured for microelectronics, integrated circuit 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 can be doped or undoped. It should be understood that the term "microelectronic device" is not meant to be limiting in any way, but includes any substrate that will eventually become a microelectronic device or microelectronic assembly.

[0090] "Substantially free" is defined herein as less than 0.001% by weight. "Substantially free" also includes 0.000% by weight. The term "free" refers to 0.000% by weight.

[0091] As used herein, "about" is intended to correspond to ±5%, preferably ±2% of the stated value.

[0092] In all such compositions where a particular component of the composition is discussed with reference to a weight percent range including a lower limit of zero, it is understood that such components may or may not be present in various embodiments of the composition, and where such components are present, they may be present in concentrations as low as 0.00001 weight percent based on the total weight of the composition in which such components are used.

[0093] The CMP slurry of the present invention comprises a dicationic polymer or copolymer.

[0094] More specifically, the CMP slurry comprises an abrasive, a dicationic polymer or copolymer, an oxidizing agent (i.e., an oxidizing agent that is not a free radical generator), an activator or catalyst, additives, and water; optionally, a corrosion inhibitor, a dishing reducer, a stabilizer, and a pH adjuster. The pH of the slurry is 1-14, preferably 1-7, more preferably 1-6, and most preferably 1.5-4.

[0095] The CMP slurry may further comprise a surfactant; a dispersant; a chelating agent; a film-forming anti-corrosion agent; a biocide; and a polishing enhancer.

[0096] abrasive

[0097] 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, and combinations thereof.

[0098] The abrasive used in the CMP slurry can be an activator-containing particle (ie, an abrasive having an activator coating); or a non-activator-containing particle.

[0099] Inorganic oxide particles include, but are not limited to, ceria, silica, alumina, titania, germania, spinel, tungsten oxide or nitride, zirconium oxide particles, or any of the foregoing doped with one or more other minerals or elements, and any combination thereof. Oxide abrasives may be produced by any of a variety of techniques, including sol-gel, hydrothermal, hydrolytic, plasma, pyrolytic, aerogel, fuming, and precipitation techniques, and any combination thereof.

[0100] Precipitated inorganic oxide particles can be obtained by known methods by reacting metal salts with acids or other precipitants. Pyrogenic metal oxide and / or metalloid oxide particles are obtained by hydrolysis of suitable gasifiable raw materials in an oxygen / hydrogen flame. An example is pyrogenic silica from silicon tetrachloride. Pyrogenic oxides of aluminum oxide, titanium oxide, zirconium oxide, silicon dioxide, cerium oxide, germanium oxide, and vanadium oxide, and chemical and physical mixtures thereof, are suitable.

[0101] 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.

[0102] The metal oxide coated organic polymer particles are selected from ceria coated organic polymer particles and zirconium oxide coated organic polymer particles.

[0103] Organic polymer particles include, but are not limited to, polystyrene particles, polyurethane particles, polyacrylate particles, or any other organic polymer particles.

[0104] Colloidal silica particles and high purity colloidal silica particles are preferred abrasive particles. The silica can be any of precipitated silica, fumed silica, fumed silica, pyrogenic silica, silica doped with one or more additives, or any other silica-based compound.

[0105] Colloidal silica particles and high-purity colloidal silica particles used as abrasives also include silica particles with surface chemical modifications through chemical coupling reactions, which allow such silica particles to have different chemical functional groups on their surfaces and have positive or negative charges under different applied pH conditions in the CMP slurry. For example, aminopolyorganosiloxane-coated silica particles, such as disclosed in US63 / 269,585 filed on March 18, 2022. Examples of such surface chemically modified silica particles include, but are not limited to, SiO2-R-NH2, -SiO-SO3M; wherein R can be, for example, (CH2) n A group wherein n ranges from 1 to 12 and M can be, for example, sodium, potassium or ammonium.

[0106] In an alternative embodiment, the silica may be produced, for example, by a method selected from the group consisting of a sol-gel method, a hydrothermal method, a plasma method, a fuming method, a precipitation method, and any combination thereof.

[0107] Abrasive is generally the form of the abrasive grain of a combination of a kind of material or different materials, usually many abrasive grains.Usually, suitable abrasive grain is more or less spherical, and effective diameter is about 10 to 700 nanometers, about 20 to 500 nanometers or about 30 to 300 nanometers (nm), although the size of single particle may be different.Particle size can be measured by dynamic light scattering (DLS).Abrasive of aggregation or agglomeration particle form is preferably further processed to form single abrasive grain.

[0108] The abrasive grains can be purified using suitable methods such as ion exchange to remove metallic impurities, which may help to improve colloidal stability. Alternatively, high purity abrasive grains are used.

[0109] In general, the above-mentioned abrasives can be used alone or in combination with each other. It may be advantageous to combine two or more abrasive particles of different sizes or different types of abrasives to obtain superior performance.

[0110] The concentration of the abrasive can range from 0.01 wt % to 30 wt %, preferably from about 0.05 wt % to about 20 wt %, more preferably from about 0.01 wt % to about 10 wt %, and most preferably from 0.1 wt % to 2 wt %. The weight percentages are relative to the composition.

[0111] 0.05 wt% to about 10 wt%, more preferably about 0.1 to about 2 wt%.

[0112] additive

[0113] The CMP slurry of the present invention comprises an additive which is a dicationic polymer or copolymer.

[0114] Yin, K. et al. describe batteries using polyelectrolytes: “Polymer electrolytes based ondicationic polymeric ionic liquids: application in lithium metal batteries”, Journal of Materials Chemistry A 2015, 3(1), 170.

[0115] Cao, W. et al. described porous membranes using polyelectrolytes: “Dual-Cationic Poly(ionicliquid)s Carrying 1,2,4-Triazolium and Imidazolium Moieties: Synthesis and Formation of a Single-Component Porous Membrane” ACS Macro Letters 2021, 10(1), 161.

[0116] Compared to polymers from the prior art, dual or dicationic polymers or copolymers have an increased charge density per molecular weight of the repeat unit and incorporate different types of cations in the repeat unit, which opens up new design possibilities.

[0117] Thus, the dicationic polymers or copolymers of the present invention possess unique properties that help reduce corrosion in highly selective metal CMP slurries.

[0118] Negatively charged polymers are generally able to electrostatically interact with oppositely charged surfaces, such as the positively charged tungsten surface. Therefore, using optimized amounts and tailored polymers can greatly improve the selectivity between metal removal and oxide layer removal while reducing the dishing effect.

[0119] At low pH values <2.5, the SiO2 layer as a classic standard oxide material is by no means partially negatively charged. 5 In other words, to simultaneously block oxide attack while recessing the metal, the polymers used require a more tailored design that goes beyond purely cationic approaches.

[0120] Surprisingly, specially designed dicationic polymers or copolymers exhibit very low dishing and erosion behavior. This unique class of polymers can be used as topography control additives and are valuable tools for designing next generation slurries.

[0121] The dicationic polymer or copolymer formed from at least one dicationic monomer comprises the structure of (I):

[0122]

[0123] in:

[0124] P1 represents a polymerizable group;

[0125] Sp1 and Sp2 independently represent a spacer group or a single bond at each occurrence;

[0126] R1, R2 and R3 are each independently H; or a substituted or unsubstituted aliphatic or aromatic moiety selected from (1) an alkyl group having <12 C atoms, <6 C atoms, <4 C atoms or <2 C atoms, preferably CH3 or CH2-CH3; and (2) phenyl, pyridyl, pyrimidinyl, furanyl or a nitrogen-containing five-membered ring; preferably pyridyl or pyrimidinyl; and (3) a combination of (1) and (2);

[0127] Cat represents a cationic group at each occurrence; preferably an ammonium, guanidinium, triazolium, phosphonium, pyridinium, or triazolium group;

[0128] X - represents anionic counter ions.

[0129] The polymerizable group P1 is selected from groups containing a C=C double bond.

[0130] The anionic counterion is selected from halide (F-, Cl-, Br-, I-), BF4-, PF6-, carboxylate, malonate, citrate, carbonate, fumarate, MeOSO3-, MeSO3-, CF3COO-, CF3SO3-, nitrate or sulfate.

[0131] The dicationic polymer or copolymer is formed by a polymerization process selected from free radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), atom transfer polymerization (ATRP), ring opening polymerization (ROMP) and polycondensation.

[0132] The dicationic polymer or copolymer according to aspects 1-4; wherein the dicationic polymer or copolymer has block copolymer characteristics.

[0133] Examples of dicationic polymers or copolymers include, but are not limited to, poly(3-ethyl-1-(3-(1-vinyl-1H-imidazol-3-yl)propyl)-1H-imidazol-3-ium dibromide), poly(3-(tributylphosphino)propyl)-1-vinyl-1H-imidazol-3-ium dibromide), poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide), and poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium-co-N-vinyl-pyrrolidone dibromide).

[0134] The concentration of the additive ranges from about 0.00001 wt% to 1.0 wt%, about 0.0001 wt% to 0.5 wt%, about 0.00025 wt% to 0.1 wt%, or about 0.0005 wt% to 0.05 wt%.

[0135] oxidants

[0136] The CMP slurries of the present invention contain an oxidizing agent or oxidizing agent for chemical etching of materials.

[0137] The oxidant of the CMP slurry is present in the fluid composition that contacts the substrate and aids in the chemical removal of the target material from the substrate surface. Thus, the oxidant component is believed to enhance or increase the material removal rate of the composition. Preferably, the amount of oxidant in the composition is sufficient to aid the chemical removal process while minimizing operational, environmental, or similar or related issues, such as cost, as much as possible.

[0138] Advantageously, in one embodiment of the present invention, the oxidizing agent is a component that generates free radicals when exposed to at least one activator, thereby generating an increased etch rate on at least selected structures. The free radicals described below oxidize most metals and make the surface more susceptible to oxidation by other oxidizing agents. However, the oxidizing agents are listed separately from the "free radical generating compounds" discussed below because some oxidizing agents do not readily form free radicals when exposed to an activator, and in some embodiments, it is advantageous to have one or more oxidizing agents that provide matched or preferential etch rates on various metal combinations that may be present on the substrate.

[0139] As is known in the art, some oxidants are more suitable for certain components than for other components. In some embodiments of the present invention, the selectivity of the CMP system for one metal relative to another is maximized, as is known in the art. However, in certain embodiments of the present invention, the combination of oxidants is selected to provide substantially similar CMP rates (as opposed to simple etch rates) for the conductor and barrier layer combination.

[0140] In one embodiment, the oxidizing agent is an inorganic or organic per-compound.

[0141] Percompounds are generally defined as compounds containing an element in its highest oxidation state, such as perchloric acid; or compounds containing at least one peroxide group (-OO-), such as peracetic acid and perchromic acid.

[0142] Suitable percompounds containing at least one peroxide group include, but are not limited to, peracetic acid or its salts, percarbonates, and organic peroxides such as benzoyl peroxide, urea hydrogen peroxide, and / or di-tert-butyl peroxide.

[0143] Suitable percompounds containing at least one peroxide group include peroxides. As used herein, the term "peroxide" includes ROOR', wherein R and R' are each independently H, C1 to C6 linear or branched alkyl, alkanol, carboxylic acid, ketone (for example) or amine, and each of the above may be independently substituted with one or more benzyl groups (for example benzoyl peroxide), which itself may be substituted with OH or C1-C5 alkyl, as well as salts and adducts thereof. Thus, the term includes common examples such as hydrogen peroxide, peroxyformic acid, peroxyacetic acid, peroxypropionic acid, substituted or unsubstituted peroxybutyric acid, hydroperoxide-acetaldehyde, and the term also encompasses complexes of common peroxides such as urea peroxide.

[0144] Suitable percompounds containing at least one peroxide group include persulfates. As used herein, the term "persulfate" includes monopersulfates, dipersulfates, and acids, salts, and adducts thereof. Examples include peroxodisulfates, peroxymonosulfuric acid, and / or peroxymonosulfate, peroxo acid, including salts such as potassium peroxymonosulfate, but preferably non-metallic salts such as ammonium peroxymonosulfate.

[0145] Suitable percompounds containing at least one peroxy group include perphosphates as defined above, and include peroxydiphosphates.

[0146] Additionally, ozone is a suitable oxidizing agent, alone or in combination with one or more other suitable oxidizing agents.

[0147] Suitable percompounds that do not contain a peroxide group include, but are not limited to, periodic acid and / or any salts of periodic acid (hereinafter referred to as "periodates"), perchloric acid and / or any salts of perchloric acid (hereinafter referred to as "perchlorates"), perbromic acid and / or any salts of perbromic acid (hereinafter referred to as "perbromates"), and perboric acid and / or any salts of perboric acid (hereinafter referred to as "perborates").

[0148] Other oxidizing agents are also suitable components of the compositions of the present invention. Iodates are useful oxidizing agents.

[0149] Two or more oxidizing agents may be combined to obtain synergistic performance benefits.

[0150] In most embodiments of the present invention, the oxidizing agent is selected from peroxy compounds selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted peroxybutyric acid, hydroperoxide-acetaldehyde, potassium periodate, ammonium peroxymonosulfate; and non-peroxy compounds selected from ferric nitrite, KClO4, KBrO4, KMnO4.

[0151] In some embodiments, the preferred oxidizing agent is hydrogen peroxide.

[0152] The oxidizing agent concentration may range from about 0.01 wt % to 30 wt %, with a preferred concentration of the oxidizing agent being from about 0.1 wt % to 20 wt %, and a more preferred concentration of the oxidizing agent being from about 0.5 wt % to about 10 wt %. The weight percentages are relative to the composition.

[0153] Activator

[0154] An activator or catalyst is a material that interacts with the oxidant and promotes the formation of free radicals by at least one free radical generating compound present in the fluid.

[0155] The activator may be a metal-containing compound, in particular a metal selected from metals known to activate the Fenton reaction process in the presence of an oxidizing agent such as hydrogen peroxide.

[0156] The activator may be a non-metal containing compound. Iodine may be used, for example, with hydrogen peroxide to form free radicals.

[0157] If the activator is a metal ion or metal-containing compound, it is a thin layer associated with the solid surface in contact with the fluid. If the activator is a non-metallic substance, it can be dissolved in the fluid. It is preferred that the activator be present in an amount sufficient to promote the desired reaction.

[0158] Activators include, but are not limited to (1) inorganic oxide particles coated with a transition metal on the surface thereof, wherein the transition metal is selected from iron, copper, manganese, cobalt, cerium and combinations thereof; (2) soluble catalysts include, but are not limited to, iron (III) nitrate, iron (III) ammonium oxalate trihydrate, iron (III) citrate monohydrate, iron (III) acetylacetonate and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate, metal compounds with multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V; and combinations thereof.

[0159] The amount of activator in the slurry is in the range of about 0.00001 wt% to 5 wt%, about 0.0001 wt% to 2.0 wt%, about 0.0005 wt% to 1.0 wt%; or about 0.001 wt% to 0.5 wt%.

[0160] water

[0161] The polishing composition is water-based and thus contains water. Water functions in various ways within the composition, such as, for example, dissolving one or more solid components of the composition, acting as a carrier for the components, aiding in the removal of polishing residues, and acting as a diluent. Preferably, the water used in the cleaning composition is deionized (DI) water.

[0162] It is believed that for most applications, water comprises, for example, about 10 to about 90 weight % or 90 weight % water. Other preferred embodiments may comprise about 30 to about 95 weight % water. Still other preferred embodiments may comprise about 50 to about 90 weight % water. Still other preferred embodiments may include water in an amount to achieve the desired weight percentages of the other ingredients.

[0163] Corrosion inhibitor (optional)

[0164] Corrosion inhibitors used 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, triazinethiol, triazinedithiol and triazinetrithiol, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof. Preferred inhibitors are 1,2,4-triazole, 5-aminotriazole, and 1,3,5-tris(2-hydroxyethyl)isocyanurate.

[0165] 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%.

[0166] Sag reducer (optional)

[0167] The CMP composition may further comprise a dishing reducing agent or dishing reducing agent 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, 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 having three or more carbon atoms that form alkylammonium ions; aminoalkyl groups having three or more carbon atoms; polymeric corrosion inhibitors containing at least one nitrogen-containing heterocycle or a repeating group of tertiary or quaternary nitrogen atoms; dicationic 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.

[0168] When present, the dishing reducer is present in an amount ranging from about 0.001 wt% to 2.0 wt%, preferably 0.005 wt% to 1.5 wt%, more preferably 0.01 wt% to 1.5 wt%, based on the weight of the entire CMP composition.

[0169] Stabilizer (optional)

[0170] The composition can also include one or more of various optional additives. Suitable optional additives include stabilizing agents. These optional additives are generally used to promote or enhance the stability of the composition for sedimentation, flocculation (including precipitation, aggregation or agglomeration of particles, etc.) and decomposition. Stabilizers can be used to extend the pot life of oxidants (including compounds that generate free radicals) by isolating activator materials, by quenching free radicals, or by stabilizing compounds that form free radicals.

[0171] Some materials can be used to stabilize hydrogen peroxide. An exception to metal contamination is the presence of selected stabilizing metals, such as tin. In some embodiments of the invention, a small amount of tin may be present, typically less than about 25 ppm, for example, between about 3 and about 20 ppm. Similarly, zinc is also commonly used as a stabilizer. In some embodiments of the invention, zinc may be present in a small amount, typically less than about 20 ppm, for example, between about 1 and about 20 ppm. In another preferred embodiment, the fluid composition contacting the substrate has less than 500 ppm, for example, less than 100 ppm of dissolved metals with multiple oxidation states, excluding tin and zinc. In the most preferred commercial embodiment of the invention, the fluid composition contacting the substrate has less than 9 ppm of dissolved metals with multiple oxidation states, for example, less than 2 ppm of dissolved metals with multiple oxidation states, excluding tin and zinc. In some preferred embodiments of the 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).

[0172] Because metals in solution are generally discouraged, preferred are those non-metal-containing oxidants that are typically present in salt form (eg, persulfates), acid form, and / or ammonium salt form (eg, ammonium persulfate).

[0173] Other stabilizers include free radical quenchers. As discussed, these will diminish the effectiveness of the free radicals generated. Therefore, if present, it is preferred that they be present in small amounts. Most antioxidants, i.e., vitamin B, vitamin C, citric acid, etc., are free radical quenchers. Most organic acids are free radical quenchers, but three organic acids that are effective and have other beneficial stabilizing properties are phosphonic acid, the binder oxalic acid, and the non-radical scavenging chelating agent gallic acid.

[0174] Additionally, it is believed that carbonates and phosphates bind to the activator and prevent fluid contact. Carbonates are particularly useful because they can be used to stabilize the slurry, but small amounts of acid can quickly remove the stabilizing ions. Stabilizers that can be used for adsorbed activators can be film-forming agents that form a film on the silica particles.

[0175] Suitable stabilizers include organic acids such as adipic acid, phthalic acid, citric acid, malonic acid, phthalic acid; and phosphoric acid; substituted or unsubstituted phosphonic acids, i.e., phosphonic acid compounds; nitriles; and other ligands, such as those that bind to activator materials and thereby reduce reactions that degrade oxidants, as well as any combination of the foregoing agents. As used herein, acid stabilizing agents refer to acid stabilizers and their conjugate bases. That is, the various acid stabilizing agents can also be used in their conjugated forms. For example, herein, with respect to the above-mentioned acid stabilizing agents, adipic acid stabilizing agents include adipic acid and / or its conjugate base, and carboxylic acid stabilizing agents include carboxylic acids and / or their conjugate bases, carboxylates, and the like. Suitable stabilizers, used alone or in combination with one or more other stabilizers, reduce the rate at which oxidants, such as hydrogen peroxide, decompose when mixed into the CMP slurry.

[0176] On the other hand, the presence of stabilizers in the composition may impair the effectiveness of the activator. Their amount should be adjusted to match the desired 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 necessary amount will vary depending on the specific additive selected and the specific composition of the CMP composition, such as the surface properties of the abrasive component. If too little additive is used, the additive may have little or no effect on the stability of the composition. On the other hand, if too much additive is used, the additive may cause undesirable foam and / or flocculants to form in the composition.

[0177] Typically, suitable amounts of these stabilizers range from about 0.0001 to 5 weight percent, preferably about 0.00025 to 2 weight percent, and more preferably about 0.0005 to about 1 weight percent of the composition. The stabilizer can be added directly to the composition or applied to the surface of the abrasive component of the composition.

[0178] pH adjuster (optional)

[0179] The compositions disclosed herein include a pH adjusting agent. A pH adjusting agent is typically used in the compositions disclosed herein to increase or decrease the pH of the polishing composition. The pH adjusting agent can be used to improve the stability of the polishing composition, adjust the ionic strength of the polishing composition, and improve the safety of handling and use, as needed.

[0180] Suitable pH adjusting agents 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 adjusting agents 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.

[0181] When used, the amount of pH adjuster is preferably in the range of about 0.01 wt.% to about 5.0 wt.% relative to the total weight of the polishing composition. A preferred range is about 0.01 wt.% to about 1 wt.% or about 0.05 wt.% to about 0.15 wt.%.

[0182] The pH of the slurry is between 1 and 14, preferably between 1 and 7, more preferably between 1 and 6, most preferably between 1.5 and 4.

[0183] Surfactant (optional)

[0184] The compositions disclosed herein optionally include surfactants, which in part help protect the wafer surface during and after polishing to reduce defects in the wafer surface. Surfactants can also be used to control the removal rate of some films (such as low-K dielectrics) used in polishing. Suitable surfactants include nonionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants, and mixtures thereof.

[0185] The nonionic surfactant can be selected from a range of chemical types including, but not limited to, long chain alcohols, ethoxylated alcohols, ethoxylated acetylenic glycol 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 sorbitan alkyl esters, sorbitan alkyl esters, cocamide monoethanolamine, cocamide diethanolamine dodecyldimethylamine oxide, block copolymers of polyethylene glycol and polypropylene glycol, polyethoxylated tallow amine, fluorosurfactants.

[0186] The molecular weight of surfactants can range from a few hundred to over a million. These materials also have a very wide distribution of viscosities.

[0187] Anionic surfactants include, but are not limited to salts with suitable hydrophobic tails, such as alkyl carboxylates, alkyl polyacrylates, alkyl sulfates, alkyl phosphates, alkyl dicarboxylates, alkyl hydrogen sulfates, alkyl hydrogen phosphates, such as alkoxy carboxylates, alkoxy sulfates, alkoxy phosphates, alkoxy dicarboxylates, alkoxy hydrogen sulfates, alkoxy hydrogen phosphates, such as substituted aryl carboxylates, substituted aryl sulfates, substituted aryl phosphates, substituted aryl dicarboxylates, substituted aryl hydrogen sulfates and substituted aryl hydrogen phosphates etc. The counter ions of this type of surfactant include, but are not limited to potassium, ammonium and other positive ions. The molecular weight range of these anionic surface wetting agents is from several hundred to several hundred thousand.

[0188] Cationic surfactants carry a net positive charge over the major part of the molecular framework. Cationic surfactants are generally halides of molecules containing a hydrophobic chain and a cationic charge center such as amine, quaternary ammonium, benzyldimethylammonium (benzyalkonium) and alkylpyridinium ions.

[0189] On the other hand, the surfactant can be an amphoteric surfactant, which has a positive (cationic) and a negative (anionic) charge on the main molecular chain and carries their relative counterions. The cationic portion is based on a primary, secondary or tertiary amine or a quaternary ammonium cation. The anionic portion can be more variable and includes sulfonates, such as in sulfobetaine CHAPS (3-[(3-cholamidopropyl)dimethylammonium]-1-propanesulfonate) and cocamidopropyl hydroxysulfobetaine. Betaines such as cocamidopropyl betaine have carboxylic acid and ammonium. Some amphoteric surfactants can have a phosphate anion and an amine or ammonium, such as the phospholipids phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine and sphingomyelin.

[0190] Examples of surfactants also include, but are not limited to, sodium lauryl sulfate, sodium lauryl sulfate, ammonium lauryl sulfate, secondary alkyl sulfonates, alcohol ethoxylates, acetylenic surfactants, and any combination thereof. Examples of suitable commercially available surfactants include TRITON manufactured by Dow Chemicals. TM 、Tergitol TM 、DOWFAX TM Surfactant family and SURFYNOL manufactured by Air Products and Chemicals TM 、DYNOL TM , Zetasperse TM Nonidet TM and Tomadol TM Various surfactants in the surfactant family. Suitable surfactants among surfactants may also include polymers containing ethylene oxide (EO) and propylene oxide (PO) groups. Examples of EO-PO polymers are Tetronic from BASFChemicals. TM 90R4.

[0191] When used, the amount of surfactant is generally in the range of 0.0001 wt % to about 1.0 wt % relative to the total weight of the barrier CMP composition. When used, the preferred range is from about 0.010 wt % to about 0.1 wt %.

[0192] Chelating agent (optional)

[0193] The compositions disclosed herein may optionally include chelating agents to enhance the affinity of the chelating ligand for the metal cation. Chelating agents may also be used to prevent the accumulation of metal ions on the pad (which leads to pad contamination and instability in the removal rate). Suitable chelating agents include, but are not limited to, for example, amine compounds such as ethylenediamine, aminopolycarboxylic acids such as ethylenediaminetetraacetic acid (EDTA), nitrilotriacetic acid (NTA); aromatic acids such as benzenesulfonic acid, 4-toluenesulfonic acid, 2,4-diamino-benzenesulfonic acid, etc.; 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 such as glycine, serine, proline, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, arginine, threonine ... Asparagine, aspartic acid, cysteine, glutamic acid, glutamine, ornithine, selenocysteine, tyrosine, sarcosine, N-bicine, N-tricine, acetylglutamine, N-acetylaspartic acid, acetylcarnitine, acetylcysteine, N-acetylglutamic acid, acetylleucine, acivicin, S-adenosyl-L-homocysteine, agar-acid, alanosine, aminohippuric acid, L-arginine ethyl ester, aspartame, aspartylglucosamine, benzylmercaptouric acid, ε-N-biotinyl-L-lysine, brivanib alanine ester, carboxymethylcysteine, N (6)-Carboxymethyllysine, carbomer, cilastatin, cetirizine, coprine, dibromotyrosine, dihydroxyphenylglycine, eflornithine, phenclonin, 4-fluoro-L-threonine, N-formylmethionine, γ-L-glutamyl-L-cysteine, 4-(γ-glutamylamino)butyric acid, glutaurine, guanidine acetic acid, sodium ethylamine (Hadacidin), hepapressin, lisinopril, lymecycline, N-methyl-D-aspartic acid, N-methyl-L-glutamyl

[00145] The present invention also includes but is not limited to the following: amino acid, milacamide, nitrosoproline, nocardin A, nopaline, octopine, ombrabulin, opine, anthranilic acid, oxacerol, polylysine, remacemide, salicylic acid, serine, stampidine, pyrogallol, tetrazolylglycine, thiophene, thymectacin, tiopronin, tryptophan tryptoquinone, valacyclovir, valganciclovir and phosphonic acid, and derivatives thereof, such as, for example, octylphosphonic acid, aminobenzylphosphonic acid, and combinations and salts thereof.

[0194] Where chemical bonding is desired, for example, of copper and tantalum cations, chelating agents may be used to accelerate the dissolution of copper and tantalum oxides to produce desired removal rates of copper lines, vias or trenches, and barrier layers or films.

[0195] When used, the amount of chelating agent preferably ranges from about 0.01 wt% to about 3.0 wt%, more preferably from about 0.4 wt% to about 1.5 wt%, relative to the total weight of the composition.

[0196] Biocide (optional)

[0197] The CMP formulations disclosed herein may also contain additives to control biological growth, such as biocides. Some additives to control biological growth are disclosed in U.S. Patent 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, wherein the alkyl chain ranges from 1 to about 20 carbon atoms, sodium chlorite, sodium hypochlorite, isothiazolinone compounds such as methylisothiazolinone, methylchloroisothiazolinone and benzisothiazolinone. Some commercially available preservatives include KATHON from Dow Chemicals TM and NEOLENE TM Product family and Preventol from Lanxess TM family.

[0198] Preferred biocides are isothiazolinone compounds such as methylisothiazolinone, methylchloroisothiazolinone and benzisothiazolinone.

[0199] The CMP polishing composition optionally comprises a biocide in a range of 0.0001 wt.% to 0.10 wt.%, preferably 0.0001 wt.% to 0.005 wt.%, more preferably 0.0002 wt.% to 0.0025 wt.% to prevent bacterial and fungal growth during storage.

[0200] The compositions disclosed herein can be manufactured in a concentrated form and subsequently diluted with deionized water at the time of use. Other components, such as, for example, oxidants, can be retained in the form of a concentrate and added at the time of use to minimize incompatibilities between the components in the concentrate form. The compositions disclosed herein can be manufactured in two or more components, which can be mixed before use.

[0201] Working Examples

[0202] General experimental process

[0203] Unless otherwise indicated, all percentages are by weight.

[0204] Part I. Synthesis of dicationic polymers or copolymers

[0205] Unless otherwise stated, all reagents and solvents were purchased from Sigma-Aldrich (Merck) of the highest commercial grade and used as received.

[0206] Characterization methods

[0207] NMR spectra were recorded on a 500 MHz Bruker Avance II+ spectrometer using deuterated solvents from Sigma-Aldrich (Merck). Chemical shifts are reported in d values (ppm) and calibrated against the internal standard Si(OMe)4 (0.00 ppm).

[0208] The polycationic polymers were analyzed by size exclusion chromatography (SEC) at 40°C in H O / MeOH / EtOAc (54 / 23 / 23, v / v / v) containing 10 mM sodium acetate (flow rate: 0.5 mL / min). Measurements were performed on an Agilent 1260 HPLC equipped with a column set consisting of a PSS Novema precolumn and a PSS Novema MAX ultraheight column. The samples were dissolved in an eluent containing 0.1% ethylene glycol as an internal standard at 50°C. The average molar mass of the polymer was derived from the refractive index signal based on a poly(2-vinylpyridine) calibration curve.

[0209] Example 1:

[0210] Poly(3-ethyl-1-(3-(1-vinyl-1H-imidazol-3-yl)propyl)-1H-imidazol-3-ium dibromide)

[0211]

[0212] Monomer synthesis:

[0213] Synthesis of 3-(3-bromopropyl)-1-vinyl-1H-imidazol-3-ium

[0214]

[0215] 1,3-Dibromopropane (CAS: 109-64-8, 107 mL, 1.06 mol) was dissolved in acetonitrile (300 mL), and then 1-vinylimidazole (CAS: 1072-63-5, 10 g, 0.105 mol, dissolved in 40 mL of acetonitrile) was added dropwise at room temperature while stirring. The reaction mixture was heated at 65°C overnight, allowed to cool to room temperature, and ethyl acetate (1 L) was added, whereupon the crude product precipitated as an oil. The mixture was concentrated in vacuo and finally purified by column chromatography (silica gel, DCM / MeOH 95:5) to give 21.7 g (70%) of a light yellow solid.

[0216] 1 H NMR (500MHz, DMSO-d6) δ=9.62(t,J=1.6Hz,1H),8.25(t,J=1.9Hz,1H),7.98(t,J=1.9Hz,1H),7.32(dd,J=15.6,8.7Hz,1H),5.9 9(dd,J=15.6,2.4Hz,1H), 5.43(dd,J=8.8,2.4Hz,1H), 4.34(t,J=7.0Hz,2H), 3.58(t,J=6.6Hz,2H), 2.41(p,J=6.8Hz,2H)ppm.

[0217] Synthesis of 3-ethyl-1-(3-(1-vinyl-1H-imidazol-3-yl)propyl)-1H-imidazol-3-ium dibromide)

[0218]

[0219] 3-(3-Bromopropyl)-1-vinyl-1H-imidazol-3-ium (4.7 g, 16 mmol) was dissolved in 40 mL of acetonitrile and N-ethylimidazole (CAS: 7098-07-9; 1.9 g, 19 mmol, dissolved in 10 mL of acetonitrile) was added dropwise at room temperature with stirring. The reaction mixture was heated at 60°C overnight, allowed to cool to room temperature, and mixed with ethyl acetate (500 mL), whereupon an oil precipitated. The oil was washed with ethyl acetate, dissolved in water, and freeze-dried to yield 5.7 g (92%) of a solid.

[0220] 1 H NMR (500MHz, DMSO-d6) δ = 9.75 (d, J = 1.6Hz, 1H), 9.40 (t, J = 1.7Hz, 1H), 8.28 (t, J = 1.9Hz,1H),8.03(t,J=1.8Hz,1H),7.88(d,J=1.6Hz,2H),7.35(dd,J=15.7,8.7Hz ,1H),6.02(dd,J=15.6,2.4Hz,1H),5.45(dd,J=8.8,2.4Hz,1H),4.31(dt,J=12.2 ,6.9Hz,4H),4.23(q,J=7.3Hz,2H),2.53–2.45(m,2H),1.44(t,J=7.3Hz,3H)ppm.

[0221] polymerization:

[0222]

[0223] 3-Ethyl-1-(3-(1-vinyl-1H-imidazol-3-ium-3-yl)propyl)-1H-imidazol-3-ium dibromide) (5.7 g, 14.5 mmol) was dissolved in water (30 mL), 1,2′-azobis(2-methylpropionamidine) dihydrochloride (V50, CAS: 2997-92-4, 18.5 mg, 0.068 mmol) was added, and the mixture was purged with argon for 30 min and then heated under reflux overnight. The solution was allowed to cool to room temperature and then mixed with THF (250 mL) to precipitate an oil, which was dissolved in water and purified by cross-flow filtration (MWCO: 5 kDa). The purified polymer was freeze-dried to give 3.15 g (55%) of a white solid.

[0224] 1 H NMR (500 MHz, DMSO-d6) δ = 10.00 (broad s), 9.68 (broad s), 8.07 (broad s), 7.96 (broad s), 4.69 (broad s), 4.42 (broad s), 4.26 (broad s), 2.63 (broad s), 2.05 (broad s), 1.46 (broad s) ppm.

[0225] SEC: Mn: 19.0kDa; Mw: 41.1kDa; PDI: 2.1

[0226] Example 2:

[0227] Poly(3-(tributylphosphino)propyl)-1-vinyl-1H-imidazol-3-ium dibromide)

[0228]

[0229] Monomer synthesis:

[0230] 3-(3-Bromopropyl)-1-vinyl-1H-imidazol-3-ium was synthesized according to the same method described for Example 1.

[0231]

[0232] Synthesis of 3-(tributylphosphino)propyl-1-vinyl-1H-imidazol-3-ium dibromide

[0233]

[0234] 3-(3-Bromopropyl)-1-vinyl-1H-imidazol-3-ium (5.5 g, 18.6 mmol) was dissolved in 40 mL of acetonitrile and tributylphosphine (CAS: 998-40-3; 4.1 g, 20 mmol, dissolved in 10 mL of acetonitrile) was added dropwise with stirring at room temperature. The reaction mixture was heated at 60°C overnight, allowed to cool to room temperature, and mixed with tert-butyl methyl ether (MTBE, 500 mL), whereupon a solid precipitated. The crude product was washed with MTBE and dried under vacuum to yield 8 g (71%) of a colorless solid.

[0235] 1 H NMR(500MHz, DMSO-d6)δ=9.76(t,J=1.6Hz,1H),8.29(t,J=1.9Hz,1H),8.06(t,J=1 .8Hz,1H),7.37(dd,J=15.6,8.8Hz,1H),6.03(dd,J=15.6,2.4Hz,1H),5.46(dd,J=8 .7,2.4Hz,1H),4.35(t,J=6.9Hz,2H),2.38–2.26(m,1H),2.32(s,1H),2.29–2.21( m, 6H), 2.16 (dq, J = 12.4, 7.4Hz, 2H), 1.53–1.36 (m, 12H), 0.92 (t, J = 7.1Hz, 9H) ppm.

[0236] polymerization:

[0237]

[0238] 3-(Tributylphosphino)propyl-1-vinyl-1H-imidazol-3-ium dibromide (6 g, 12.4 mmol) was dissolved in water (30 mL), and 1,2′-azobis(2-methylpropionamidine) dihydrochloride (V50, CAS: 2997-92-4, 13.9 mg, 0.05 mmol) was added. The mixture was purged with argon for 30 minutes and then heated under reflux overnight. The solution was cooled to room temperature and then purified by cross-flow filtration (MWCO: 3 kDa). The purified polymer was freeze-dried to yield 2.1 g (35%) of a white solid.

[0239] 1 H NMR (500 MHz, DMSO-d6) δ = 10.00 (broad s), 8.44 (broad s), 4.54 (broad s), 2.22 (broad s), 1.54 (broad s), 1.43 (broad s), 0.93 (broad s) ppm.

[0240] SEC: Mn: 11.0kDa; Mw: 22.3kDa; PDI: 2.0.

[0241] Example 3:

[0242] Poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide)

[0243]

[0244] Monomer synthesis:

[0245] Synthesis of 3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide

[0246]

[0247] (2-Bromoethyl)trimethylammonium bromide (CAS: 2758-06-7, 25 g, 101 mmol) was dissolved in 150 mL of acetonitrile and 1-vinylimidazole (CAS: 1072-63-3; 10.7 g, 112.5 mmol) was added dropwise with stirring at room temperature. The reaction mixture was heated at 60° C. overnight, allowed to cool to room temperature, and mixed with ethyl acetate (500 mL), whereupon oil precipitated. The crude product was washed with ethyl acetate, dissolved in water, and freeze-dried to yield 32.7 g (85%) of a colorless solid.

[0248] 1 H NMR (500MHz, DMSO-d6) δ=9.60(t,J=1.6Hz,1H),8.18(t,J=1.9Hz,1H),8.00(t,J=1.9Hz,1H),7.29(dd,J=15.6,8.6Hz,1H) ,5.95(dd,J=15.6,2.6Hz,1H),5.46(dd,J=8.7,2.6Hz,1H),4.82(t,J=7.1Hz,2H),3.98(t,J=7.1Hz,2H),3.19(s,9H)ppm.

[0249] polymerization:

[0250]

[0251] 3-(2-(Trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide (5 g, 14.8 mmol) was dissolved in water (30 mL), 1,2'-azobis(2-methylpropionamidine) dihydrochloride (V50, CAS: 2997-92-4, 13.6 mg, 0.05 mmol) was added, and the mixture was purged with argon for 30 min and then heated under reflux overnight. The solution was allowed to cool to room temperature and then mixed with THF (250 mL). Oil precipitated, which was dissolved in water and purified by cross-flow filtration (MWCO: 5 kDa). The purified polymer was freeze-dried to obtain 4.7 g (94%) of a white solid.

[0252] 1 H NMR (500 MHz, DMSO-d6) δ = 9.79 (broad s), 8.15 (broad s), 8.01 (broad s), 4.88 (broad s), 4.29 (broad s), 3.3 (broad s), 2.63 (broad s) ppm.

[0253] SEC: Mn: 24kDa; Mw: 73kDa; PDI: 3.0.

[0254] Example 4:

[0255] Poly(3-(2-(trimethylammonium)ethyl)-1-vinyl-1H-imidazol-3-ium-co-N-vinyl-pyrrolidone dibromide)

[0256]

[0257] Monomer synthesis:

[0258] Synthesis of 3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide

[0259]

[0260] The same procedure as described in Example 3 was used.

[0261] Polymerization Example 4-1:

[0262]

[0263] 3-(2-(Trimethylammonium)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide (4 g, 11.7 mmol) and 1-vinyl-2-pyrrolidone (CAS: 88-12-0, 3.9 g, 35.2 mmol) were dissolved in DMF / water (1:1, 60 mL) and mixed with 2,2'-azobisisobutyronitrile (AIBN, CAS: 78-67-1, 13.3 mg, 0.08 mmol). The mixture was purged with argon for 30 min and then heated under reflux overnight. The solution was cooled to room temperature and mixed with ethyl acetate (500 mL), and an oil precipitated, which was dissolved in water and purified by cross-flow filtration (MWCO: 10 kDa). The purified polymer was freeze-dried to give 3.8 g (48%) of a white solid.

[0264] 1 H NMR (500 MHz, DMSO-d6) δ = 9.71 (broad s), 8.13 (broad s), 4.84 (broad s), 4.03 (broad s), 3.61 (broad s), 3.26 (broad s), 2.37 (broad s), 1.90 (broad s) ppm.

[0265] SEC: Mn: 35kDa; Mw: 119kDa; PDI: 3.4.

[0266] Polymerization Example 4-2:

[0267] The same procedure as described in Example 4-1 was used except that 11.7 g (105.5 mmol) of 1-vinyl-2-pyrrolidone (CAS: 88-12-0) was used. The purified polymer was freeze-dried to obtain 8.8 g (56%) of a white solid.

[0268] 1 H NMR (500 MHz, DMSO-d6) δ: 9.71 (broad s), 8.05 (broad s), 7.76 (broad s), 4.80 (broad s), 4.01 (broad s), 3.74 (broad s), 3.54 (broad s), 3.22 (broad s), 2.27 (broad s), 2.09 (broad s), 1.90 (broad s), 1.62 (broad s), 1.31 (broad s) ppm.

[0269] SEC: Mn: 41kDa; Mw: 272kDa; PDI: 6.6.

[0270] Polymerization Example 4-3:

[0271] The same method as described in Example 4-1 was used, except that 2 g (5.9 mmol) of 3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium and 12.4 g (111 mmol) of 1-vinyl-2-pyrrolidone (CAS: 88-12-0) were used. The purified polymer was freeze-dried to obtain 10.3 g (72%) of a white solid.

[0272] 1 H NMR (500 MHz, DMSO-d6) δ: 9.46 (broad s), 8.01 (broad s), 7.70 (broad s), 4.78 (broad s), 3.95 (broad s), 3.75 (broad s), 3.56 (broad s), 3.19 (broad s), 2.07 (broad s), 1.87 (broad s), 1.63 (broad s), 1.32 (broad s) ppm.

[0273] SEC: Mn: 29kDa; Mw: 207kDa; PDI: 7.0.

[0274] Some IICMP experiments

[0275] Use the phosphonium-based polymer synthesized in Part I

[0276] The polishing compositions and related methods described herein are effective for CMP of a wide variety of substrates, including most substrates, and are particularly useful for polishing tungsten substrates.

[0277] In the examples given below, CMP experiments were carried out using the procedures and experimental conditions given below.

[0278] parameter:

[0279] Angstrom - unit of length

[0280] BP: back pressure, in psi

[0281] CMP: Chemical Mechanical Planarization = Chemical Mechanical Polishing

[0282] CS: Carrier speed

[0283] DF: Downforce: The pressure applied during CMP, in psi

[0284] min: minutes

[0285] ml: milliliters

[0286] mV: millivolt

[0287] psi: pounds per square inch

[0288] PS: The platen speed of the polishing equipment, unit rpm (revolutions per minute)

[0289] SF: polishing composition flow rate, ml / min

[0290] TEOS: Silicon oxide film obtained by chemical vapor deposition (CVD) using tetraethyl orthosilicate as a precursor

[0291] wt%: weight percentage (of the listed components)

[0292] Removal rate (RR) = (film thickness before polishing - film thickness after polishing) / polishing time.

[0293] Removal rate and selectivity

[0294] Tungsten removal rate: Tungsten removal rate measured at a down pressure of 3.0 psi in the CMP apparatus.

[0295] TEOS removal rate: TEOS removal rate measured at a given downforce. The downforce of the CMP apparatus was 3.0 psi.

[0296] SiN removal rate: The SiN removal rate measured at a given downforce. The downforce of the CMP apparatus was 3.0 psi.

[0297] The CMP equipment used in the examples is AMAT 200mm It is 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 studies.

[0298] 200 mm diameter silicon wafers coated with tungsten films, TEOS films, SiN films or SKW patterned structures containing tungsten were obtained from SKW Associate, Inc. 2920 Scott Blvd, Santa Clara, CA 95054. The polishing time for the blanket film was one minute. The tungsten removal rate was measured using a sheet resistance measurement technique. The removal of TEOS was measured using an optical technique. The patterned wafers were polished on an Ebara polisher for a period of time based on eddy current technology. The polishing time for the patterned wafers exceeded the endpoint determined by the eddy current endpoint technique by 15 seconds. The patterned wafers were analyzed using a KLA Tencor P15 profiler (large feature size) or an AFM tool (small feature size).

[0299] Polishing was performed using a platen speed of 111 RPM, a carrier speed of 113 RPM, a slurry flow rate of 200 ml / min, and a down force of 3.0 psi.

[0300] During the polishing process, a substrate (e.g., a blanket W or patterned W wafer) is placed face down on a polishing pad that is fixedly attached to a rotatable platen of a CMP polisher. In this way, the substrate to be polished and planarized is in direct contact with the polishing pad. A wafer carrier system or polishing head is used to hold the substrate in place and apply downward pressure to the back of the substrate while the platen and substrate rotate during the CMP process. During the CMP process, a polishing composition (slurry) is applied (usually continuously) to the polishing pad to effectively remove material and planarize the substrate.

[0301] In the following working examples, four base CMP slurries (without the dicationic polymer) were prepared in water with 0.01 wt% ferric nitrate (iron (III) nitrate), 0.08 wt% malonic acid (stabilizer), 2.0 wt% hydrogen peroxide, 0.1 wt% glycine, and 0.25 wt%, and 0.3 wt% of one of the following abrasive particles: Fuso PL-2C silica particles (base 1), silica particles coated with amino-polyorganosiloxane (particularly 3-aminopropyl-methyldimethoxysilane) as disclosed in WO 2023 / 178286 A1 in base 2 (20 mmol / g functionalization degree and matrix particle size 80 nm), base 3 (48 mmol / g functionalization degree and matrix particle size 80 nm), and base 4 (48 mmol / g functionalization degree and matrix particle size 90 nm), and the pH was adjusted to 2.3 with nitric acid.

[0302] Various dicationic polymers were added to the base slurry to obtain the working slurry.

[0303] The effects of dicationic polymers on tungsten, TEOS, and SiN removal rates, erosion, and dishing were tested.

[0304] The removal rates and selectivities of W:TEOS are shown in Table 1.

[0305] Table 1. Membrane removal rate and membrane selectivity

[0306]

[0307]

[0308] As shown in Table 1, the addition of a small amount of the synthesized dicationic polymer provides a high tungsten removal rate and a very low TEOS removal rate, resulting in a high selectivity.

[0309] Tungsten dishing was tested on various arrays, including a 0.18 x 0.18 micron array (tungsten line width / trench separated by dielectric line width / spacer, in microns) (0.18 / 0.18 μm), a 7 x 3 micron array (7 / 3 μm), and a 1 x 1 micron array (1 / 1 μm). After the patterned wafer polish endpoint was detected using eddy current measurement, the wafer was polished for an additional 20 seconds, or the overpolish (OP) time. The W line dishing data is shown in Table 2.

[0310] Table 2. W line depression

[0311]

[0312]

[0313] For wider lines, line dishing generally increases. In a typical tungsten CMP process, it is expected that the tungsten dishing for wider line features is less than 1500 angstroms.

[0314] As shown in Table 2, the addition of a small amount of the synthetic dicationic polymer provides low W line depression.

[0315] As shown in Table 3, erosion was tested on 7 / 3 μm, 1 / 1 μm, and 50 / 50 μm arrays with a 20 second overpolish.

[0316] Table 3. Erosion

[0317]

[0318]

[0319] Erosion of an array generally increases as pattern density increases. In a typical tungsten CMP process, it is desirable to have erosion on high density features, such as 70% and 90%.

[0320] As shown in Table 3, the addition of a small amount of a synthetic dicationic polymer provides low erosion.

[0321] Although the principles of the present invention have been described above in conjunction with preferred embodiments, it should be clearly understood that this description is merely exemplary and not intended to limit the scope of the invention. Instead, the subsequent detailed description of the preferred exemplary embodiments will provide those skilled in the art with a description of implementing the preferred exemplary embodiments of the present invention. Various changes may be made to the function and arrangement of the elements without departing from the spirit and scope of the invention as set forth in the appended claims.

Claims

1. A dicationic polymer or copolymer formed from at least one dicationic monomer comprising a structure of formula (I) below; in: P1 represents a polymerizable group; Sp1 and Sp2 independently represent a spacer group or a single bond at each occurrence; R1, R2 and R3 are each independently H; or a substituted or unsubstituted aliphatic or aromatic moiety selected from (1) an alkyl group having <12 C atoms, <6 C atoms, <4 C atoms or <2 C atoms, preferably CH3 or CH2-CH3; and (2) phenyl, pyridyl, pyrimidinyl, furanyl or a nitrogen-containing five-membered ring; preferably pyridyl or pyrimidinyl; and (3) a combination of (1) and (2); Cat represents a cationic group at each occurrence; preferably an ammonium, guanidinium, triazolium, phosphonium, pyridinium or triazolium group; X - represents anionic counter ions. 2 . The dicationic polymer or copolymer according to claim 1 , wherein the polymerizable group P1 is selected from groups containing a C═C double bond.

3. The dicationic polymer or copolymer according to claims 1-2, wherein the anionic counterion is selected from halides selected from F-, Cl-, Br- and I-; BF4-; PF6-; carboxylates; malonates; citrates; carbonates; fumarates; MeOSO3-; MeSO3-; CF3COO-; CF3SO3-; nitrates; and sulfates.

4. The dicationic polymer or copolymer according to claims 1-3, wherein the dicationic polymer or copolymer is formed by a polymerization method selected from the group consisting of free radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), atom transfer reaction polymerization (ATRP), ring-opening polymerization (ROMP), and polycondensation.

5. The dicationic polymer or copolymer according to claims 1-4, wherein the dicationic polymer or copolymer has block copolymer characteristics.

6. The dicationic polymer or copolymer according to claims 1-5, wherein the dicationic polymer or copolymer is selected from the group consisting of poly(3-ethyl-1-(3-(1-vinyl-1H-imidazol-3-yl)propyl)-1H-imidazol-3-ium dibromide), poly(3-(tributylphosphino)propyl)-1-vinyl-1H-imidazol-3-ium dibromide), poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium dibromide), poly(3-(2-(trimethylammonio)ethyl)-1-vinyl-1H-imidazol-3-ium-co-N-vinyl-pyrrolidone dibromide), and combinations thereof.

7. A chemical mechanical planarization composition comprising the dicationic polymer or copolymer according to any one of claims 1 to 6.

8. 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; Activator; oxidants; An additive comprising a dicationic polymer or copolymer according to any one of claims 1 to 6; water; and optionally corrosion inhibitors; sag reducers; stabilizers; pH adjuster.

9. The chemical mechanical planarization composition of claim 8, wherein the abrasive is in a range of 0.01 wt% to 30 wt%, 0.05 wt% to 20 wt%, 0.01 wt% to 10 wt%, or 0.1 wt% to 2 wt%.

10. The chemical mechanical planarization composition of any one of claims 8-9, wherein the additive comprising a dicationic polymer or copolymer is in a range of 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%.

11. The chemical mechanical planarization composition according to any one of claims 8 to 10, wherein the oxidizing agent is selected from peroxy compounds selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted peroxybutyric acid, hydroperoxide-acetaldehyde, potassium periodate, ammonium peroxymonosulfate; and non-peroxy compounds selected from ferric nitrite, KClO4, KBrO4, KMnO4; and combinations thereof; and the range of the oxidizing agent is 0.01 wt%-30 wt%, 0.1 wt%-20 wt% or 0.5 wt%-10 wt%.

12. The chemical mechanical planarization composition according to any one of claims 8 to 11, wherein the activator is selected from (1) inorganic oxide particles having a transition metal coated on their surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce and combinations thereof; (2) a soluble catalyst selected from iron (III) nitrate, iron (III) ammonium oxalate trihydrate, iron (III) citrate monohydrate, iron (III) acetylacetonate and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate; (3) a metal compound with multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V; and combinations thereof; and the range of the activator is 0.00001 wt%-5.0 wt%, 0.0001 wt%-2.0 wt%, 0.0005 wt%-1.0 wt% or 0.001 wt%-0.5 wt%.

13. The chemical mechanical planarization composition of any one of claims 8 to 12, wherein the corrosion inhibitor is selected from 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, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof; and the corrosion inhibitor is present in an amount of less than 1.0 wt%, less than 0.5 wt%, or less than 0.25 wt%.

14. The chemical mechanical planarization composition of any one of claims 8 to 13, wherein the pH adjuster 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, to lower the pH; and (b) potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof, to increase the pH.

15. The chemical mechanical planarization composition of any one of claims 8 to 14, wherein the pH of the composition is 1-14, 1-7, 1-6, or 1.5-4.

16. A chemical mechanical planarization composition according to any one of claims 8 to 15, wherein the dishing reducer 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, 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; aminoalkyl groups with three or more carbon atoms; polymeric corrosion inhibitors containing at least one nitrogen-containing heterocycle or a repeating group of a tertiary or quaternary nitrogen atom; dicationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; and sulfonic acid polymers; and combinations thereof; and the dishing reducer is in the range of 0.001 wt% to 2.0 wt%, 0.005 wt% to 1.5 wt% or 0.01 wt% to 1.0 wt%.

17. The chemical mechanical planarization composition of any one of claims 8 to 16, wherein the stabilizer is selected from adipic acid, phthalic acid, citric acid, malonic acid, phthalic acid; phosphoric acid; substituted or unsubstituted phosphonic acid; nitriles; and combinations thereof; and the stabilizer is present in an amount ranging from 0.0001 to 5 wt%, 0.00025 to 2 wt%, or 0.0005 to 1 wt%.

18. The chemical mechanical planarization composition of any one of claims 8-17, wherein the abrasive is silica particles.

19. The chemical mechanical planarization composition of any one of claims 8 to 18, wherein the chemical mechanical planarization composition comprises silica particles; poly(vinyl-3-ethyl-1H-imidazol-3-ium-co-tributyl-(4-vinylbenzyl)-phosphonium) bromide chloride, iron (III) nitrate, malonic acid, hydrogen peroxide, and water; and the pH of the composition is 1.5 to 4.

20. A polishing method for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten-containing surface, comprising the steps of: a) providing a polishing pad; b) providing a chemical mechanical polishing 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; Activator; oxidants; An additive comprising a dicationic polymer or copolymer according to any one of claims 1 to 6; water; and optionally corrosion inhibitors; sag reducers; stabilizers; pH adjusters; and c) polishing the at least one tungsten-containing surface with the chemical mechanical planarization composition.

21. The polishing method of claim 20, wherein the chemical mechanical planarization composition has the abrasive in a range of 0.01 wt%-30 wt%, 0.05 wt%-20 wt%, 0.01 wt%-10 wt%, or 0.1 wt%-2 wt%.

22. The polishing method of any one of claims 20-21, wherein the additive comprising a dicationic polymer or copolymer is in a range of 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.%.

23. The polishing method according to any one of claims 20 to 22, wherein the oxidizing agent is selected from a peroxy compound selected from hydrogen peroxide, urea peroxide, peroxyformic acid, peroxyacetic acid, peroxypropionic acid, substituted or unsubstituted peroxybutyric acid, hydroperoxide-acetaldehyde, potassium periodate, ammonium peroxymonosulfate; and a non-peroxy compound selected from ferric nitrite, KClO4, KBrO4, KMnO4; and combinations thereof; and the oxidizing agent is in the range of 0.01 wt% to 30 wt%, 0.1 wt% to 20 wt% or 0.5 wt% to 10 wt%.

24. The polishing method according to claim 20 , wherein the activator is selected from (1) inorganic oxide particles coated with a transition metal on the surface thereof; and the transition metal is selected from Fe, Cu, Mn, Co, Ce and combinations thereof; (2) a soluble catalyst selected from iron (III) nitrate, iron (III) ammonium oxalate trihydrate, iron (III) citrate monohydrate, iron (III) acetylacetonate and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate; (3) a metal compound with multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V; and combinations thereof; and the range of the activator is 0.00001 wt%-5.0 wt%, 0.0001 wt%-2.0 wt%, 0.0005 wt%-1.0 wt% or 0.001 wt%-0.5 wt%.

25. The polishing method according to any one of claims 20 to 24, wherein the corrosion inhibitor is selected from 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, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof; and the corrosion inhibitor is present in an amount of less than 1.0 wt%, less than 0.5 wt%, or less than 0.25 wt%.

26. The polishing method according to any one of claims 20 to 25, wherein the pH adjuster is selected from (a) nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids and mixtures thereof to lower the pH; and (b) potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine and mixtures thereof to increase the pH.

27. The polishing method according to any one of claims 20 to 26, wherein the pH of the composition is 1-14, 1-7, 1-6, or 1.5-4.

28. The polishing method of any one of claims 20 to 27, wherein 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, 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 having three or more carbon atoms that form alkylammonium ions; aminoalkyl groups having three or more carbon atoms; polymeric corrosion inhibitors containing at least one nitrogen-containing heterocycle or a repeating group of a tertiary or quaternary nitrogen atom; dicationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; and sulfonic acid polymers; and combinations thereof; and the dishing-reducing agent is present in a range of 0.001 wt% to 2.0 wt%, 0.005 wt% to 1.5 wt%, or 0.01 wt% to 1.0 wt%.

29. The polishing method according to any one of claims 20 to 28, wherein the stabilizer is selected from adipic acid, phthalic acid, citric acid, malonic acid, phthalic acid; phosphoric acid; substituted or unsubstituted phosphonic acid; nitriles; and combinations thereof; and the range of the stabilizer is 0.0001-5 wt%, 0.00025-2 wt% or 0.0005-1 wt%.

30. The polishing method according to any one of claims 20 to 29, wherein the abrasive is silica particles.

31. The polishing method of any one of claims 20 to 30, wherein the chemical mechanical planarization composition comprises silicon dioxide particles; iron (III) nitrate; malonic acid; hydrogen peroxide; poly(vinyl-3-ethyl-1H-imidazol-3-ium-co-tributyl-(4-vinylbenzyl)-phosphonium) bromide chloride, and water; and the pH of the composition is 1.5 to 4.

32. The polishing method of any one of claims 20-31, wherein at least one tungsten-containing surface comprises a recessed topography of less than 2000 angstroms or less than 1000 angstroms and an eroded topography of less than 2000 angstroms or less than 1000 angstroms.

33. A system for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten-containing surface, comprising: a) polishing pad; and b) a chemical mechanical polishing 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; Activator; oxidants; An additive comprising a cationic polymer or copolymer according to any one of claims 1 to 6; water; and optionally corrosion inhibitors; sag reducers; stabilizers; pH adjuster; and The at least one tungsten-containing surface is contacted with the polishing pad and the chemical mechanical planarization composition, thereby polishing the at least one tungsten-containing surface with the chemical mechanical planarization composition.

34. The system of claim 33, wherein the chemical mechanical planarization composition has a range of 0.01 wt%-30 wt%, 0.05 wt%-20 wt%, 0.01 wt%-10 wt%, or 0.1 wt%-2 wt% of the abrasive.

35. The system of any one of claims 33-34, wherein the additive comprising a dicationic polymer or copolymer is in a range of 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%.

36. The system of any one of claims 33-35, wherein the abrasive is silica particles.

37. The system of any one of claims 33-36, wherein the oxidant is selected from a peroxy compound selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted peroxybutyric acid, hydroperoxide-acetaldehyde, potassium periodate, ammonium peroxymonosulfate; and a non-peroxy compound selected from ferric nitrite, KClO4, KBrO4, KMnO4; and combinations thereof; and the oxidant is in the range of 0.01 wt%-30 wt%, 0.1 wt%-20 wt% or 0.5 wt%-10 wt%.

38. The system of any one of claims 33-37, wherein the activator is selected from (1) inorganic oxide particles having a transition metal coated on their surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) a soluble catalyst selected from iron (III) nitrate, iron (III) ammonium oxalate trihydrate, iron (III) citrate monohydrate, iron (III) acetylacetonate, and ethylenediaminetetraacetic acid, iron (III) sodium salt hydrate; (3) a metal compound having multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V, and combinations thereof; and the range of the activator is 0.00001 wt%-5.0 wt%, 0.0001 wt%-2.0 wt%, 0.0005 wt%-1.0 wt%, or 0.001 wt%-0.5 wt%.

39. The system of any one of claims 33-38, wherein 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, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl)isocyanurate, and combinations thereof; and the corrosion inhibitor is present in a range of less than 1.0 wt%, less than 0.5 wt%, or less than 0.25 wt%.

40. The system of any one of claims 33-39, wherein 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, to lower the pH; and (b) potassium hydroxide, sodium hydroxide, ammonia, tetraethylammonium hydroxide, ethylenediamine, piperazine, polyethyleneimine, modified polyethyleneimine, and mixtures thereof, to increase the pH.

41. The system of any one of claims 33-40, wherein the pH of the composition is 1-14, 1-7, 1-6, or 1.5-4.

42. The system of any one of claims 33-41, wherein the sinking reducer 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, 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 having three or more carbon atoms that form alkylammonium ions; aminoalkyl groups having three or more carbon atoms; polymeric corrosion inhibitors containing at least one nitrogen-containing heterocycle or a repeating group of a tertiary or quaternary nitrogen atom; dicationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; and sulfonic acid polymers; and combinations thereof; and the sinking reducer is in the range of 0.001 wt%-2.0 wt%, 0.005 wt%-1.5 wt% or 0.01 wt%-1.0 wt%.

43. The system of any one of claims 33-42, wherein the stabilizer is selected from the group consisting of adipic acid, phthalic acid, citric acid, malonic acid, phthalic acid; phosphoric acid; substituted or unsubstituted phosphonic acids; nitriles; and combinations thereof; and the stabilizer ranges from 0.0001-5 wt%, 0.00025-2 wt%, or 0.0005-1 wt%.

44. The system of any one of claims 33-43, wherein the chemical mechanical planarization composition comprises silicon dioxide particles; iron (III) nitrate; malonic acid; hydrogen peroxide; poly(vinyl-3-ethyl-1H-imidazol-3-ium-co-tributyl-(4-vinylbenzyl)-phosphonium) bromide chloride, and water; and the pH of the composition is 1.5-4.

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