Guanidine-based polymer liquids and their use as additives for chemical mechanical planarization slurries

Abstract

Synthesis of guanidino polymers is disclosed. A chemical mechanical planarization (CMP) slurry includes an abrasive; an activator; an oxidant; an additive comprising a guanidino polymer; and water. The use of synthetic guanidino polymers in CMP slurries reduces sagging and erosion in high selectivity tungsten slurries.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Application No. 63 / 377,626, filed on September 29, 2022, the entire content of which is incorporated herein by reference for all permitted purposes. Background of the Invention

[0004] This disclosure relates to a chemical mechanical planarization or polishing (“CMP”) slurry (or composition or formulation), a polishing method, and a polishing system for use in the production of semiconductor devices. In particular, this disclosure relates to a polishing slurry suitable for polishing patterned semiconductor wafers comprising tungsten-containing metal materials.

[0005] Integrated circuits are interconnected by using well-known multi-level interconnections. The interconnect structure typically has a first metallization layer, an interconnect layer, a second metallization layer, and usually 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 by using metallization vias, particularly tungsten vias. U.S. Patent No. 4,789,648 describes a method for fabricating multiple metallization layers and metallization vias in an insulating film. In a similar manner, metal contacts are used to form electrical connections between the interconnect layer and devices formed in the well. Metal vias and contacts are typically filled with tungsten, and an adhesion layer such as titanium nitride (TiN) and / or titanium is typically employed to adhere a metal layer (such as a tungsten metal layer) to the dielectric material.

[0006] In one semiconductor manufacturing process, metallization vias or contacts are formed by blanket tungsten deposition followed by a CMP step. In a typical process, a via hole is etched through an interlayer dielectric (ILD) to an interconnect line or a semiconductor substrate. Next, a thin adhesion layer such as titanium nitride and / or titanium is typically formed on the ILD and guided into the etched via hole. Then, a tungsten film is blanket deposited on the adhesion layer and into the via. Deposition continues until the via hole is filled with tungsten. Finally, excess tungsten is removed by CMP to form a metal via.

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

[0008] For decades, chemical mechanical polishing or planarization (CMP) has been successfully used in the manufacturing process of integrated circuits. It is considered a key and enabling technology for miniaturization requirements. Reducing defects during the CMP process has always been important, but the smaller feature sizes and devices at the 7nm node and higher have even more stringent requirements for the acceptable level of defects during polishing.

[0009] In a typical CMP process, the substrate makes 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, a grinding and chemically reactive solution, commonly referred to as 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 brings 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 / pad interface, the polishing process is facilitated by the rotational movement of the pad relative to the substrate. Polishing continues in this manner until the desired film on the insulator is removed. The removal of tungsten in CMP is believed to be due to the synergistic effect between mechanical abrasion and tungsten oxidation and subsequent dissolution.

[0010] Despite its relatively simple external appearance, chemical mechanical planarization (CMP) is a highly complex process, as described by Lee Cook in the digital Encyclopedia of Applied Physics, 2019, DOI: 10.1002 / 3527600434.eap847. Most of the time, CMP technology has evolved faster than can be understood from what is described in Seo, J. A review on chemical and mechanical phenomena at the wafer interface during chemical mechanical planarization. Journal of Materials Research 2021, 36(1), 235.

[0011] As a technology to meet the requirements for device size scaling in the past and future and the new trends in the semiconductor industry, its importance is indisputable. A large number of interactions between the wafer, slurry, and pad, as well as general process parameters, determine the result of CMP. Finally, material removal in CMP is the result of a complex interaction between chemical and mechanical forces, as described by Lee, D.; Lee, H.; Jeong, H. in Slurry components in metal chemical mechanical planarization (CMP) process: A review. International Journal of Precision Engineering and Manufacturing 2016, 17, 1751. A large number of materials are used in semiconductor device manufacturing, and all of these require an optimized CMP process. Simultaneously polishing a combination of completely different materials, such as dielectric materials, barrier layers, and metal layers, is a real challenge for CMP.

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

[0013] In CMP, especially in metal applications such as tungsten, one of the problems often encountered is how to control topographical defects such as erosion and dishing.

[0014] The CMP process performance with a reduced defect rate can be controlled by intelligent slurry design. Specifically designed water-based slurries are considered the main driving factor for improving CMP performance for future devices. The development of slurries not only affects the removal rate and selectivity between different layers but also controls defects during the polishing process. Generally speaking, the slurry composition is a complex combination of abrasives and chemical components with different functions. Polymer additives play a key role in minimizing surface defects by interacting with certain materials. For example, positively charged polymers inhibit the removal of tungsten and can be used to reduce the dishing effect in the tungsten CMP process.

[0015] US 5,876,490 describes the use of a polishing slurry that contains abrasive particles and exhibits a normal stress effect, and further contains a polyelectrolyte with a charged ionic moiety, the charge being different from the charge associated with the abrasive particles, and wherein the concentration of the polyelectrolyte is about 5 to about 50 wt% of the abrasive particles, and wherein the molecular weight of the polyelectrolyte is about 500 to about 10,000.

[0016] US2010 / 0075501A1 describes a chemical mechanical polishing aqueous dispersion for polishing a polishing target including a tungsten-containing interconnect layer. The chemical mechanical polishing aqueous dispersion includes: (A) a cationic water-soluble polymer; (B) an iron(III) compound; and (C) colloidal silica particles. The content (M A )(mass %) of the cationic water-soluble polymer (A) and the content (M B )(mass %) of the iron(III) compound (B) satisfy the relationship "M A / M B = 0.004 to 0.1". The pH of the chemical mechanical polishing aqueous dispersion is 1 to 3.

[0017] 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 includes: (A) a cationic water-soluble polymer; (B) an iron(III) compound; and (C) colloidal silica having an average particle size of 10 to 60 nm calculated from the specific surface area measured by the BET method. The content (M A )(mass %) of the cationic water-soluble polymer (A) and the content (M C )(mass %) of the colloidal silica (C) satisfy the relationship "M A / M C = 0.0001 to 0.003".

[0018] US2009 / 0081871A1 discloses a method that includes chemically mechanically polishing a substrate with the inventive polishing composition that includes a liquid carrier, a cationic polymer, an acid, and abrasive particles that have been treated with an aminosilane compound.

[0019] US2014 / 0248823A1 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 ζ potential Za measured in the absence of the polymer, and the abrasive particles have a ζ potential Zb measured in the presence of the polymer, wherein the ζ potential Za is a value having the same sign as the overall charge of the polymer, and (iii) |zeta potential Zb| > |zeta potential Za|. The invention also provides a method of polishing a substrate with the polishing composition.

[0020] In a previous patent (US5,876,490), the use of polyelectrolytes such as poly(acrylic acid), poly(methacrylic acid), poly(vinylsulfonic acid), poly(acrylic acid-co-maleic acid), poly(vinylamine), poly(ethyleneimine), and poly(4-vinylpyridine) as slurry components to achieve a higher degree of planarization was described. Other published works generally reported on "cationic water-soluble polymers" such as polyvinylpyrrolidone, polyallylamine, polyvinylpiperazine, or polylysine and their positive effects in tungsten CMP (US2010 / 0075501A1 and US2010 / 0252774A1).

[0021] Typically, the polyelectrolytes described inherently contain ammonium-type nitrogen-containing cations. Imidazolium-type cationic polymers, phosphonium group-based polyionic liquids, guanidine- or triazolium-based polymers, or the synergistic effects of different cation types in the copolymer backbone were identified in U.S. Provisional Application 63 / 191,047, filed May 20, 2021; U.S. Provisional Application 63 / 209,306, filed Jun. 10, 2021; U.S. Provisional Application 63 / 251,127, filed Oct. 1, 2021; and U.S. Provisional Application 63 / 362,810, filed Apr. 11, 2022, each of which is incorporated herein by reference in its entirety, and are used in CMP slurries.

[0022] In CMP, particularly in metal (such as tungsten) applications, one of the problems frequently encountered is the dishing of tungsten lines and the erosion of metal line arrays. Dishing and erosion are key CMP parameters that define the planarity of the polished wafer. For wider lines, the dishing of the line typically increases. The erosion of the array generally increases with increasing pattern density.

[0023] In addition, metal CMP is based on the Fenton reaction, which converts a hard metal layer into a soft oxide layer that can be easily removed by mechanical abrasion. However, these oxidative conditions can lead to corrosion defects that limit the overall CMP results.

[0024] Tungsten CMP slurries must be formulated such that dishing, erosion, and corrosion can be minimized to meet certain design goals critical to functional devices.

[0025] Finding solutions to control topography defects such as erosion and dishing is key to future CMP requirements. There is still a need for novel tungsten CMP slurries that can reduce dishing and erosion while maintaining a desired removal rate during polishing. Summary of the Invention

[0027] The present invention meets the need by providing an intelligently designed tungsten CMP slurry, system, and method of using the CMP slurry to minimize the dishing and erosion problems described in highly selective tungsten slurries while maintaining the desired polishing of metal layers, particularly tungsten films.

[0028] Polymer additives play a key role as dispersants and passivators in slurry development in order to obtain the desired removal rate, selectivity, and degree of defects.

[0029] The present invention discloses the synthesis of guanidine-based multi-ionic liquids; and demonstrates the use of the synthesized guanidine-based multi-ionic liquids in CMP slurries to reduce the problems described by regulating the removal rate and selectivity and controlling the overall topography with reduced dishing and erosion.

[0030] A guanidine-based polymer or copolymer is formed by more than one monomer having at least one guanidine group; or a cationic polymer or copolymer having more than one repeating unit with at least one guanidine group.

[0031] In addition, several specific aspects of the present invention are outlined below.

[0032] Aspect 1: A guanidine-based polymer or copolymer formed by more than one monomer having more than one guanidine group with the following structure:

[0033]

[0034] Wherein:

[0035] P 1 represents a polymerizable group,

[0036] Sp 1 represents a spacer group; preferably Sp 1 has a substituted or unsubstituted aliphatic moiety with single bonds at both of its ends;

[0037] R 1 is H or a substituted or unsubstituted aliphatic moiety, wherein CH 2 can be replaced by O, S, or N in a manner that no heteroatoms are connected to each other; preferably R 1 is H, CH3 or CH 2 -CH 3 ;

[0038] R 2 is H or a substituted or unsubstituted aliphatic moiety; preferably R 2 is H or CH 3 ;

[0039] R 3 is H or a substituted or unsubstituted aliphatic moiety, and two R 3 groups may form a bridge between the nitrogen atoms to form a five-membered, six-membered or seven-membered ring; preferably R 3 is H or CH 3 , or two R 3 groups form a bridge between the nitrogen atoms to form a five-membered ring;

[0040] and

[0041] X - represents an anionic counterion.

[0042] Aspect 2: The guanidine polymer or copolymer according to Aspect 1, wherein the polymerizable group P 1 includes but is not limited to styryl (or vinylbenzene), acrylic acid or methacrylic acid, vinyl ether, allyl ether, acrylamide or methacrylamide, ethylene oxide, propylene oxide, maleimides, siloxanes, norbornene, groups containing a C═C double bond, and combinations thereof, and preferably a group containing a C═C double bond.

[0043] Aspect 3: A guanidine polymer or copolymer comprising more than one repeating unit having the following structure:

[0044]

[0045] wherein:

[0046] n represents an integer, and 1 < n < 4000, 50 < n < 2000 or 75 < n < 1000;

[0047] R 1 is H or a substituted or unsubstituted aliphatic moiety, preferably R 1 is H, CH 3 or CH 2 -CH 3 ;

[0048] R 2 is H or a substituted or unsubstituted aliphatic moiety, and two R 2 groups may also form a bridge between the nitrogen atoms to form a five-membered, six-membered or seven-membered ring; preferably R 2 is H or CH3 , or two R 2 groups form a bridge between the nitrogen atoms to form a five-membered ring;

[0049] and

[0050] X - represents an anion counterion.

[0051] Aspect 4: The guanidine polymer or copolymer according to Aspects 1 to 3, wherein the anion counterion X - is selected from halide ions (F - , Cl - , Br - or I - ), BF 4 - , PF 6 - , carboxylate, malonate, citrate, carbonate, fumarate, MeOSO 3 - , MeSO 3 - , CF 3 COO - , CF 3 SO 3 - , nitrate and sulfate, where Me is methyl.

[0052] Aspect 5: The guanidine polymer or copolymer according to Aspects 1 to 4, wherein the guanidine polymer or copolymer is formed by a polymerization method selected from free radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), atom transfer reaction polymerization (ATRP), ring-opening polymerization (ROMP) or polycondensation reaction.

[0053] Aspect 6: The guanidine polymer or copolymer according to Aspects 1 to 5, wherein the copolymer has block copolymer characteristics.

[0054] Aspect 7: The guanidine polymer or copolymer according to Aspects 1 to 5, wherein the guanidine polymer or copolymer is poly(vinylbenzyl-N-(bis(dimethylamino)methylene-N-methyl)methanaminium chloride), poly(3-acrylamido-N-(bis(dimethylamino)methylene-N-methylpropane-1-aminium bromide), poly(N-(1,3-dimethylimidazolidin-2-ylidene)-N-methyl-1-(4-vinylphenyl)methanaminium chloride); or poly(1-(bis(dimethylamino)methylene)-3,4-ethylenepyrrolidin-1-ium bromide).

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

[0056] Abrasive;

[0057] Activator;

[0058] Oxidizing agent;

[0059] An additive comprising a guanidine polymer or copolymer of aspects 1 to 7;

[0060] Water; and optionally

[0061] Corrosion inhibitor;

[0062] Dent reducer;

[0063] Stabilizer;

[0064] pH regulator.

[0065] Aspect 9: A system for chemical mechanical planarization, comprising:

[0066] A semiconductor substrate comprising at least one tungsten-containing surface;

[0067] A polishing pad; and

[0068] The chemical mechanical planarization composition of aspect 8;

[0069] Wherein the at least one tungsten-containing surface is in contact with the polishing pad and the chemical mechanical planarization composition.

[0070] Aspect 10: A polishing method for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten-containing surface, comprising the steps of:

[0071] a) Contacting the at least one tungsten-containing surface with a polishing pad;

[0072] b) Providing the chemical mechanical planarization composition of aspect 8; and

[0073] c) Polishing the at least one tungsten-containing surface with the chemical mechanical planarization composition.

[0074] The abrasive includes, but is not limited to, inorganic oxide particles, inorganic oxide particles coated with metal oxides, organic polymer particles, organic polymer particles coated with metal oxides, surface-modified inorganic oxide particles, and combinations thereof.

[0075] The inorganic oxide particles include, but are not limited to, cerium dioxide, colloidal silica, high-purity colloidal silica, fumed silica, colloidal cerium oxide, alumina, titanium dioxide, zirconia particles.

[0076] The metal oxide-coated inorganic oxide particles include, but are not limited to, cerium dioxide-coated inorganic oxide particles such as cerium dioxide-coated colloidal silica, cerium dioxide-coated high-purity colloidal silica, cerium dioxide-coated alumina, cerium dioxide-coated titanium dioxide, cerium dioxide-coated zirconia, or any other cerium dioxide-coated inorganic oxide particles.

[0077] The organic polymer particles include, but are not limited to, polystyrene particles, polyurethane particles, polyacrylate particles, or any other organic polymer particles.

[0078] The metal oxide-coated organic polymer particles include, but are not limited to, cerium dioxide-coated organic polymer particles, zirconia-coated organic polymer particles.

[0079] The surface-modified inorganic oxide particles include, but are not limited to, SiO 2 -R-NH 2 、-SiO-R-SO 3 M; where R can be, for example, (CH2) n group, where n ranges from 1 to 12, and M can be, for example, sodium, potassium, or ammonium. Examples of such surface-chemically modified silica particles include, but are not limited to, Fuso PL-2C from Fuso Chemical Company.

[0080] 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 to about 10 wt%, and most preferably from 0.1 wt% to 2 wt%. The weight percentages are relative to the composition.

[0081] The activator includes, but is not limited to: (1) inorganic oxide particles coated with a transition metal on the surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) soluble catalysts selected from iron(III) nitrate, ammonium iron(III) oxalate trihydrate, iron(III) citrate monohydrate, iron(III) acetylacetonate, and ethylenediaminetetraacetic acid, iron(III) sodium hydrate; (3) metal compounds having multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V; and combinations thereof.

[0082] The range of the activator is from 0.00001 wt% to 5.0 wt%, from 0.0001 wt% to 2.0 wt%, from 0.0005 wt% to 1.0 wt%, or from 0.001 wt% to 0.5 wt%.

[0083] The oxidizing agent includes, but is not limited to, peroxides selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted perbutyric acid, hydroperoxy-acetaldehyde, potassium periodate, ammonium peroxymonosulfate; and non-peroxides selected from ferrous nitrite, KClO 4 , KBrO 4 , KMnO 4 .

[0084] The concentration of the oxidizing agent can range from about 0.01 wt% to 30 wt%, preferably from about 0.1 wt% to 20 wt%, and more preferably from about 0.5 wt% to about 10 wt%. The weight percentage is relative to the composition.

[0085] The total amount of the additive containing the guanidine polymer or copolymer ranges from 0.00001 wt% to 1.0 wt%, 0.0001 wt% to 0.5 wt%, 0.0002 wt% to 0.1 wt%, or 0.0005 wt% to 0.05 wt%.

[0086] Suitable pH regulators 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 regulators for increasing 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.

[0087] 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.

[0088] The CMP slurry may further comprise a surfactant; a dispersant; a chelating agent; a film-forming corrosion inhibitor; and a biocide.

[0089] Other aspects, features, and embodiments of the present invention will become more apparent from the following disclosure and the appended claims.

[0090] Embodiments of the present invention can be used alone or in combination with each other. Detailed Description of the Invention

[0092] The present invention meets the need by providing an intelligently designed tungsten CMP slurry, system, and method of using the CMP slurry to reduce the dishing and erosion problems described in high-selectivity slurries while maintaining the desired polishing of the metal layer, particularly the tungsten film.

[0093] More specifically, the present invention discloses the synthesis of guanidine polymers or copolymers; and it has been demonstrated that the use of the synthesized guanidine polymers or copolymers in CMP slurries alleviates the described problems by modulating the removal rate and selectivity and controlling the overall topography with reduced dishing and erosion.

[0094] Highly selective slurries (which have a large difference between the metal removal rate and the dielectric removal rate) are of great interest for future industrial requirements. Most of the time, due to the need for long over-polishing times, the use of these slurries is associated with high levels of CMP defects such as metal dishing or oxide erosion.

[0095] In addition, metal CMP is based on the Fenton reaction, which transforms the hard metal layer into a soft oxide layer that can be easily removed by mechanical abrasion. However, these oxidative conditions can lead to corrosion defects that limit the overall CMP results.

[0096] Topographical defects such as metal dishing or oxide erosion make it very difficult to meet the performance and selectivity goals of many CMP applications and pose a major challenge in the development of increasingly smaller integrated circuits.

[0097] Specific water-soluble cationic polymers are key elements in specialty slurry formulations for reducing defects while achieving the desired removal rate and selectivity. These polymer additives play a key role as dispersants and passivators in slurry development in order to obtain the desired removal rate, selectivity, and degree of defects.

[0098] Negatively charged polymers are generally able to electrostatically interact with oppositely charged surfaces such as positively charged tungsten surfaces. Therefore, using optimized amounts and customized polymers can significantly increase the selectivity between metal removal and oxide layer removal while reducing the dishing effect.

[0099] You, K. et al. (ECS Journal of Solid State Science and Technology 2017, 6(12), P822) teach that at low pH values < 2.5, the SiO 2 layer, as a classical standard oxide material, is not partially negatively charged. In other words, in order to prevent oxide erosion while having metal dishing, the polymers used require a more customized design, which goes beyond the pure cationic approach.

[0100] The guanidine or guanidinium cation group is a unique functional group with unique properties, mainly characterized by their ability to strongly interact with various anionic functional groups by forming ion pairs in combination with strong hydrogen bonds. The positive charge at the guanidinium cation can be evenly distributed among the three nitrogens by resonance. Many key mechanisms of life and biochemistry are based on these special properties in principle, as proteins and enzymes often use the guanidinium cation functional group to recognize and bind anions, as taught by Hannon, C.L. et al. (Bioorganic Chemistry Frontiers; Dugas, H.; Schmidtchen, F.P., Eds.; Springer Berlin Heidelberg: Berlin, Heidelberg, 1993, DOI: 10.1007 / 978-3-642-78110-0_6).

[0101] Among the polymers for CMP slurries, guanidine polymers have surprisingly not been described as additives for CMP slurries.

[0102] A guanidine-based polymer or copolymer is a cationic polymer or copolymer formed from more than one monomer having at least one guanidine group; or having more than one repeating unit having at least one guanidine group. Guanidine-based polymers or copolymers include homopolymers, random copolymers, and block copolymers.

[0103] Polymers having a guanidine structure are not only characterized by their interaction with metal atoms. In addition, due to their cationic nature, they can electrostatically interact with several oppositely charged surfaces and result in a positive effect on the removal rate, selectivity, and CMP defects.

[0104] A comparative study of different cationic polyvinylbenzene polymers in current applications shows very low dishing and erosion properties for guanidine-based polymers over all other tested cationic types. In short, guanidine-based polymers can be a new tool in advanced slurry design, which expands the existing toolbox of topography control polymers.

[0105] All references cited herein, including published publications, patent applications, and patents, are hereby incorporated by reference as if each reference had been individually and specifically indicated to be incorporated by reference and were set forth in full herein.

[0106] In the context of describing the present invention (especially in the context of the appended claims), the use of the terms "a", "an", "the", and similar indicative words shall be construed to cover the singular and the plural, unless otherwise stated herein or clearly contradicted by the context. Unless otherwise stated, the terms "comprising", "having", "including", and "containing" are construed as open-ended terms (i.e., meaning "including, but not limited to"). Unless otherwise stated herein, the recitation of numerical ranges herein is merely intended to be a shorthand method for separately referring to each individual value falling within the range, and each individual value is incorporated into the specification as if it were recited herein individually. Unless otherwise stated herein or clearly contradicted by the context, all methods described herein can be performed in any suitable order. The use of any and all examples or exemplary language (e.g., "such as") provided herein is merely for the purpose of better illustrating the present invention and does not constitute a limitation on the scope of the present invention, unless otherwise stated. No language in the specification should be construed as indicating that any non-claimed element is essential for the practice of the present invention. The use of the term "comprising" in the specification and claims includes the narrower language of "consisting essentially of" and "consisting of".

[0107] Embodiments are described herein, including the best mode known to the inventors for practicing the present invention. Variations of those embodiments may become apparent to those of ordinary skill in the art after reading the foregoing description. The inventors expect skilled artisans to appropriately employ those variations, and the inventors intend for the present invention to be practiced otherwise than as specifically described herein. Accordingly, the present invention includes all modifications and equivalents of the subject matter recited in the appended claims as permitted by applicable law. In addition, the present invention includes any combination of the above elements in all possible variations, unless otherwise stated herein or clearly contradicted by the context.

[0108] 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 microelectromechanical 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 may 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 ultimately become a microelectronic device or microelectronic component.

[0109] "Substantially free of" is defined herein as less than 0.001 wt%. "Substantially free of" also includes 0.000 wt%. The term "free of" means 0.000 wt%.

[0110] As used herein, "about" is intended to correspond to ±5%, preferably ±2%, of the stated value.

[0111] In all such compositions where the specific components of the composition are discussed with reference to weight percentage ranges including a zero lower limit, it should be understood that such components may or may not be present in various specific embodiments of the composition, and in the case where such components are present, they may be present at a concentration as low as 0.00001% by weight based on the total weight of the composition in which such components are used.

[0112] The present invention has several specific aspects.

[0113] One aspect is the synthesis of a guanidyl polymer or copolymer by a polymerization method selected from free radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), atom transfer reaction polymerization (ATRP), ring-opening metathesis polymerization (ROMP), or polycondensation reaction.

[0114] Another aspect is a CMP slurry comprising an abrasive, an oxidizing agent (i.e., an oxidizing agent that is not a free radical generator), an activator or catalyst, an additive comprising a guanidyl cationic polymer or copolymer, and water; optionally a corrosion inhibitor, a dishing reducer, a stabilizer, and a pH regulator. 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.

[0115] 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.

[0116] Yet another aspect is a system for chemical mechanical planarization, comprising:

[0117] a semiconductor substrate comprising at least one tungsten-containing surface;

[0118] a polishing pad; and

[0119] a chemical mechanical planarization composition;

[0120] wherein the at least one tungsten-containing surface is in contact with the polishing pad and the chemical mechanical planarization composition.

[0121] Moreover, yet another aspect is a polishing method for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten-containing surface, comprising the steps of:

[0122] bringing the at least one tungsten-containing surface into contact with a polishing pad;

[0123] delivering a chemical mechanical planarization composition; and

[0124] The at least one tungsten-containing surface is polished with a chemical mechanical planarization composition.

[0125] Abrasive

[0126] 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.

[0127] The abrasive used in the CMP slurry can be activator-containing particles (i.e., abrasives having an activator coating); or non-activator-containing particles.

[0128] Inorganic oxide particles include, but are not limited to, cerium dioxide, silica, alumina, titanium dioxide, germanium oxide, spinel, tungsten oxides or nitrides, zirconia particles, or any of the foregoing doped with one or more other minerals or elements, and any combination thereof. Oxide abrasives can be produced by any of a variety of techniques, including sol-gel, hydrothermal, hydrolysis, plasma, pyrolysis, aerogel, fuming, and precipitation techniques, and any combination thereof.

[0129] Precipitated inorganic oxide particles can be obtained by known methods through the reaction of metal salts with acids or other precipitating agents. Pyrolytic metal oxide and / or metalloid oxide particles are obtained by hydrolysis of suitable vaporizable feedstocks in an oxygen / hydrogen flame. An example is pyrolytic silica from silicon tetrachloride. Pyrolytic oxides of alumina, titanium dioxide, zirconia, silica, cerium dioxide, germanium oxide, and vanadium oxide, and their chemical and physical mixtures are suitable.

[0130] Metal oxide-coated inorganic oxide particles include, but are not limited to, cerium dioxide-coated or alumina-coated inorganic oxide particles, such as cerium dioxide-coated colloidal silica, alumina-coated colloidal silica, cerium dioxide-coated high-purity colloidal silica, alumina-coated high-purity colloidal silica, cerium dioxide-coated alumina, cerium dioxide-coated titanium dioxide, alumina-coated titanium dioxide, cerium dioxide-coated zirconia, alumina-coated zirconia, or any other cerium dioxide-coated or alumina-coated inorganic oxide particles.

[0131] Metal oxide-coated organic polymer particles are selected from cerium dioxide-coated organic polymer particles and zirconia-coated organic polymers.

[0132] Organic polymer particles include, but are not limited to, polystyrene particles, polyurethane particles, polyacrylate particles, or any other organic polymer particles.

[0133] Colloidal silica particles and high-purity colloidal silica particles are preferred abrasive particles. The silica can be any one of precipitated silica, fumed silica, pyrogenic silica, doped silica with one or more additives, or any other silica-based compound.

[0134] The colloidal silica particles and high-purity colloidal silica particles used as abrasives also include silica particles surface chemically modified by a chemical coupling reaction, which makes the surface of such silica particles carry different chemical functional groups and have a positive or negative charge under different applied pH conditions in the CMP slurry. Examples of such surface chemically modified silica particles include, but are not limited to, SiO 2 -R-NH 2 、-SiO-R-SO 3 M; where R can be, for example, a (CH 2 ) n group, where n ranges from 1 to 12, and M can be, for example, sodium, potassium, or ammonium.

[0135] Examples of such surface chemically modified silica particles include, but are not limited to, Fuso PL-2C from Fuso Chemical Company.

[0136] In an alternative embodiment, silica can be produced, for example, by a method selected from the sol-gel method, hydrothermal method, plasma method, fuming method, precipitation method, and any combination thereof.

[0137] The abrasive is typically in the form of abrasive particles of one material or a combination of different materials, usually many abrasive particles. Although the size of individual particles can vary, suitable abrasive particles are generally more or less spherical and have an effective diameter of about 10 to 700 nanometers, about 20 to 500 nanometers, or about 30 to 300 nanometers (nm). Abrasives in the form of aggregated or agglomerated particles are preferably further processed to form individual abrasive particles.

[0138] The abrasive particles can be purified by a suitable method such as ion exchange to remove metal impurities, which may help improve the colloidal stability. Alternatively, high-purity abrasive particles are used.

[0139] Generally, the above 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 excellent performance.

[0140] The concentration of the abrasive can range from 0.01 wt% to 30 wt%. Preferably, it is about 0.05 wt% to about 20 wt%, more preferably about 0.01 wt% to about 10 wt%, and most preferably 0.1 wt% to 2 wt%. The weight percentage is relative to the composition.

[0141] Additive

[0142] The CMP slurry of the present invention contains an additive which is a guanidine polymer or copolymer.

[0143] The guanidine polymer or copolymer is formed by a polymerization method selected from free radical polymerization, reversible addition-fragmentation chain transfer polymerization (RAFT), nitroxide-mediated polymerization (NMP), atom transfer reaction polymerization (ATRP), ring-opening metathesis polymerization (ROMP), or polycondensation reaction.

[0144] The guanidine polymer or copolymer is a cationic polymer or copolymer formed from more than one monomer having at least one guanidine group, wherein the monomer contains the following structure:

[0145]

[0146] Wherein:

[0147] P 1 represents a polymerizable group,

[0148] Sp 1 represents a spacer group; preferably Sp 1 has a substituted or unsubstituted aliphatic moiety with single bonds at its two ends;

[0149] R 1 is H or a substituted or unsubstituted aliphatic moiety, wherein CH 2 can be replaced by O, S or N in a manner that no heteroatoms are connected to each other, preferably R 1 is CH 3 or CH 2 -CH 3 ;

[0150] R 2 is H or a substituted or unsubstituted aliphatic moiety, preferably R 2 is H, CH 3 or CH 2 -CH 3 ;

[0151] R 3 is H or a substituted or unsubstituted aliphatic moiety, and two R 3 groups can form a bridge between the nitrogen atoms to construct a five-membered, six-membered or seven-membered ring; preferably R 3 is H or CH3 , or two R 3 groups form a bridge between the nitrogen atoms to form a five-membered ring;

[0152] and

[0153] X - represents an anion counterion.

[0154] The polymerizable group P 1 includes but is not limited to styryl (or vinylbenzene), acrylic acid or methacrylic acid, vinyl ether, allyl ether, acrylamide or methacrylamide, ethylene oxide, propylene oxide, maleimide, siloxane, norbornene, groups containing a C═C double bond, and combinations thereof, and preferably groups containing a C═C double bond.

[0155] The anion counterion X - includes but is not limited to halide ions (F - , Cl - , Br - or I - ), BF 4 - , PF 6 - , carboxylate, malonate, citrate, carbonate, fumarate, MeOSO 3 - , MeSO 3 - , CF 3 COO - , CF 3 SO 3 - , nitrate or sulfate, where Me is methyl.

[0156] The guanidine polymer or copolymer is a cationic polymer or copolymer having repeating units with the following structure:

[0157]

[0158] wherein:

[0159] n is an integer, and 1 < n < 4000, 50 < n < 2000 or 75 < n < 1000;

[0160] R 1 is H or a substituted or unsubstituted aliphatic moiety, preferably R 1 is H, CH 3 or CH 2 -CH 3 ;

[0161] R 2is H or a substituted or unsubstituted aliphatic moiety, and two R 2 groups may also form a bridge between the nitrogen atoms to form a five-membered, six-membered or seven-membered ring; preferably R 2 is H or CH 3 or two R 2 groups form a bridge between the nitrogen atoms to form a five-membered ring;

[0162] and

[0163] X - represents an anionic counterion.

[0164] The anionic counterion X - includes, but is not limited to, halide ions (F - , Cl - , Br - or I - ), BF 4 - , PF 6 - , carboxylate, malonate, citrate, carbonate, fumarate, MeOSO 3 - , MeSO 3 - , CF 3 COO - , CF 3 SO 3 - , nitrate or sulfate.

[0165] The concentration of the guanidine polymer or copolymer additive ranges from about 0.00001 wt% to 1.0 wt%, 0.0001 wt% to 0.5 wt%, 0.0002 wt% to 0.1 wt% or 0.0005 wt% to 0.05 wt%.

[0166] Oxidizing agent

[0167] The CMP slurry of the present invention contains an oxidizing agent or oxidation reagent for chemical etching of materials.

[0168] The oxidizing agent of the CMP slurry is in the fluid composition in contact with the substrate and helps to chemically remove the target material on the substrate surface. Therefore, the oxidizing agent component is considered to increase or enhance the material removal rate of the composition. Preferably, the amount of the oxidizing agent in the composition is sufficient to assist the chemical removal process while minimizing as much as possible processing, environmental or similar or related issues such as cost.

[0169] Advantageously, in one embodiment of the present invention, the oxidizer is a component that generates free radicals when exposed to at least one activator, thereby creating an increased etch rate on at least selected structures. The free radicals described below will oxidize most metals and make the surface more susceptible to oxidation by other oxidizers. However, the oxidizer is listed separately from the "free radical generating compounds" discussed below because some oxidizers do not readily form free radicals when exposed to an activator, and in some embodiments, it is advantageous to have one or more oxidizers that provide a matched etch or preferential etch rate on the various combinations of metals that may be present on the substrate.

[0170] As is known in the art, some oxidizers are more suitable for certain components than for others. 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, a combination of oxidizers is selected to provide substantially similar CMP rates (as opposed to simple etch rates) for a conductor and barrier layer combination.

[0171] In one embodiment, the oxidizer is an inorganic or organic per-compound.

[0172] Per-compounds are generally defined as compounds that contain an element in its highest oxidation state, such as perchloric acid; or compounds that contain at least one peroxide group (-O-O-), such as peracetic acid and perchromic acid.

[0173] Suitable per-compounds that contain 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 peroxide, and / or di-tert-butyl peroxide.

[0174] Suitable per-compounds that contain at least one peroxide group include peroxides. As used herein, the term "peroxide" includes R-O-O-R′, where R and R′ are each independently H, C 1 to C 6 straight-chain or branched alkyl, alkanol, carboxylic acid, ketone (e.g.), or amine, and each of the foregoing may independently be substituted by one or more benzyl groups (such as benzoyl peroxide), which itself may be substituted by OH or C 1 -C 5 alkyl, and their salts and adducts. Thus, the term includes common examples such as hydrogen peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted perbutyric acid, hydroperoxide-acetaldehyde, and the term also includes complexes of common peroxides such as urea peroxide.

[0175] Suitable percompounds containing at least one peroxy group include persulfates. As used herein, the term "persulfate" includes monopersulfates, diperoxysulfates, and their acids, salts, and adducts. This includes, for example, peroxydisulfates, peroxymonosulfuric acid and / or peroxymonosulfate salts, Caro's acid, including salts such as potassium peroxymonosulfate, but preferably non-metallic salts such as ammonium peroxymonosulfate.

[0176] Suitable percompounds containing at least one peroxy group include perphosphates as defined above and include peroxydiphosphates.

[0177] In addition, ozone is a suitable oxidizing agent, either alone or in combination with one or more other suitable oxidizing agents.

[0178] Suitable percompounds that do not contain a peroxy group include, but are not limited to, periodic acid and / or any salt of periodic acid (hereinafter referred to as "periodate"), perchloric acid and / or any salt of perchloric acid (hereinafter referred to as "perchlorate"), perbromic acid and / or any salt of perbromic acid (hereinafter referred to as "perbromate"), and perboric acid and / or any salt of perboric acid (hereinafter referred to as "perborate").

[0179] Other oxidizing agents are also suitable components of the compositions of the present invention. Iodates are useful oxidizing agents.

[0180] Two or more oxidizing agents can be combined to obtain synergistic performance benefits.

[0181] In most embodiments of the present invention, the oxidizing agent is selected from percompounds 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-percompounds selected from ferrous nitrite, KClO 4 、KBrO 4 、KMnO 4 。

[0182] In some embodiments, the preferred oxidizing agent is hydrogen peroxide.

[0183] The oxidizing agent concentration can range from about 0.01 wt% to 30 wt%, while the preferred concentration of the oxidizing agent is from about 0.1 wt% to 20 wt%, and the more preferred concentration of the oxidizing agent is from about 0.5 wt% to about 10 wt%. The weight percentages are relative to the composition.

[0184] Activator

[0185] An activator or catalyst is a material that interacts with the oxidizing agent and promotes the formation of free radicals through at least one free radical-generating compound present in the fluid.

[0186] The activator can be a metal-containing compound, particularly a metal selected from the group consisting of metals known to activate the Fenton reaction process in the presence of an oxidizing agent such as hydrogen peroxide.

[0187] The activator can be a non-metal-containing compound. Iodine can be used, for example, with hydrogen peroxide to form free radicals.

[0188] If the activator is a metal ion or a metal-containing compound, it is a thin layer associated with the solid surface in contact with the fluid. If the activator is a non-metal-containing substance, it can be dissolved in the fluid. Preferably, the activator is present in an amount sufficient to promote the desired reaction.

[0189] Activators include, but are not limited to: (1) inorganic oxide particles coated with a transition metal on the surface, where the transition metal is selected from iron, copper, manganese, cobalt, cerium, and combinations thereof; (2) soluble catalysts including, but not limited to, iron(III) nitrate, ammonium iron(III) oxalate trihydrate, iron(III) citrate monohydrate, iron(III) acetylacetonate, and ethylenediaminetetraacetic acid, iron(III) sodium hydrate, metal compounds of Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, V having multiple oxidation states; and combinations thereof.

[0190] The amount of activator in the slurry ranges from about 0.00001 wt% to 5 wt%, preferably from about 0.0001 wt% to 2.0 wt%, more preferably from about 0.0005 wt% to 1.0 wt%; and most preferably from 0.001 wt% to 0.5 wt%.

[0191] Water

[0192] The polishing composition is water-based and thus contains water. In the composition, water acts in various ways, such as, for example, dissolving one or more solid components of the composition, serving as a carrier for the components, serving as an aid for removing polishing residues, and serving as a diluent. Preferably, the water used in the cleaning composition is deionized (DI) water.

[0193] It is believed that for most applications, water contains, for example, from about 10 to about 90 wt% or 90 wt% of water. Other preferred embodiments may contain from about 30 to about 95 wt% of water. Still other preferred embodiments may contain from about 50 to about 90 wt% of water. Yet other preferred embodiments may include an amount of water to achieve the desired weight percentage of the other components.

[0194] Corrosion inhibitor (optional)

[0195] The 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, triazinethiols, triazinedithiols and triazinetrithiols, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl) ester and mixtures thereof. Preferred inhibitors are 1,2,4-triazole, 5-aminotriazole and 1,3,5-tris(2-hydroxyethyl) isocyanurate.

[0196] The amount of the 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%.

[0197] Dishing reducer (optional)

[0198] The CMP composition may further comprise a dishing reducer or a dishing reducing agent selected from sarcosinates and related carboxylic acid compounds; hydrocarbon-substituted sarcosinates; amino acids; organic polymers and copolymers having molecules with 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 a compound; nitrogen-containing compounds having three or more carbon atoms that form alkylammonium ions; aminoalkyls having three or more carbon atoms; polymeric corrosion inhibitors comprising at least one nitrogen-containing heterocycle or repeating groups of tertiary or quaternary nitrogen atoms; polycationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; sulfonic acid polymers. Glycine is a preferred dishing reducer.

[0199] When a dishing reducer is present, the amount of the dishing reducer ranges 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 by weight.

[0200] Stabilizer (optional)

[0201] The composition may 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 stabilization of the composition against settling, flocculation (including precipitation, aggregation or agglomeration of particles, etc.) and decomposition. Stabilizers can be used to extend the storage period of oxidants (including compounds that generate free radicals) by sequestering activator materials, by quenching free radicals, or by otherwise stabilizing compounds that form free radicals.

[0202] 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 present invention, a small amount of tin may be present, generally less than about 25 ppm, for example, about 3 to about 20 ppm. Similarly, zinc is also commonly used as a stabilizer. In some embodiments of the present invention, a small amount of zinc may be present, generally less than about 20 ppm, for example, between about 1 and 20 ppm. In another preferred embodiment, the fluid composition in contact with the substrate has less than 500 ppm, for example, less than 100 ppm of dissolved metals having multiple oxidation states (other than tin and zinc). In the most preferred commercial embodiments of the present invention, the fluid composition in contact with the substrate has less than 9 ppm of dissolved metals having multiple oxidation states, for example, less than 2 ppm of dissolved metals having multiple oxidation states, other than tin and zinc. In some preferred embodiments of the present invention, the fluid composition in contact with the substrate has less than 50 ppm, preferably less than 20 ppm, more preferably less than 10 ppm of total dissolved metals, other than tin and zinc.

[0203] Since metals in solution are generally disadvantageous, preferred are those non-metal-containing oxidants that are typically present in the form of salts (such as persulfates), in acid form and / or in the form of ammonium salts (such as ammonium persulfate).

[0204] Other stabilizers include free radical quenchers. As discussed, these will attenuate the effectiveness of the generated free radicals. Therefore, if present, it is preferred that they be present in small amounts. Most antioxidants, namely 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 chelating agent oxalic acid, and the non-free radical scavenging chelating agent gallic acid.

[0205] In addition, it is believed that carbonates and phosphates bind to the activator and impede the access of the fluid. Carbonates are particularly useful because they can be used to stabilize the slurry, but a small amount of acid can quickly remove the stabilizing ions. The stabilizing agent for the activator that can be used for adsorption can be a film-forming agent to form a film on the silica particles.

[0206] 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., phosphonate compounds; nitriles; and other ligands, such as those that bind to activator materials and thereby reduce reactions that degrade oxidants, and any combination of the foregoing agents. As used herein, an acid stabilizing agent refers to an acid stabilizer and its conjugate base. That is, various acid stabilizing agents may also be used in their conjugated form. For example, in this article for the above-mentioned acid stabilizing agents, adipic acid stabilizing agents include adipic acid and / or its conjugate base, carboxylic acid stabilizing agents include carboxylic acids and / or its conjugate base, 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.

[0207] On the other hand, the presence of stabilizers in the composition may impair the efficacy of the activator. Its amount should be adjusted to match the desired stability with the minimum adverse effect 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 varies 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 has 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 floccules to form in the composition.

[0208] Typically, suitable amounts of these stabilizers are in the range of about 0.0001 to 5 wt %, preferably about 0.00025 to 2 wt %, more preferably about 0.0005 to about 1 wt % relative to the composition. The stabilizer can be added directly to the composition or applied to the surface of the abrasive component of the composition.

[0209] pH adjuster (optional)

[0210] The compositions disclosed herein include a pH adjusting agent. A pH adjusting agent is generally 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.

[0211] Suitable pH adjusters for lowering the pH of the polishing composition include, but are not limited to, nitric acid, sulfuric acid, tartaric acid, succinic acid, citric acid, malic acid, malonic acid, various fatty acids, various polycarboxylic acids, and mixtures thereof. Suitable pH adjusters for increasing 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.

[0212] When in use, the amount of the pH regulator is preferably in the range of about 0.01 wt% to about 5.0 wt% relative to the total weight of the polishing composition. Preferred ranges are about 0.01 wt% to about 1 wt% or about 0.05 wt% to about 0.15 wt%.

[0213] 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.

[0214] Surfactant (optional)

[0215] The compositions disclosed herein optionally contain surfactants that in part help to 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.

[0216] Nonionic surfactants can be selected from a range of chemical types including, but not limited to, long-chain alcohols, ethoxylated alcohols, ethoxylated acetylenic diol surfactants, polyethylene glycol alkyl ethers, propylene glycol alkyl ethers, glucoside alkyl ethers, polyethylene glycol octyl phenyl ethers, polyethylene glycol alkyl phenyl ethers, glycerol alkyl esters, polyethylene glycol sorbitan alkyl esters, sorbitan alkyl esters, coconut monoethanolamide, coconut diethanolamide, dodecyldimethylamine oxide, block copolymers of polyethylene glycol and polypropylene glycol, polyethoxylated tallow amine, fluorinated surfactants.

[0217] The molecular weight range of surfactants can range from several hundred to over one million. The viscosities of these materials also have a very wide distribution.

[0218] Anionic surfactants include, but are not limited to, salts with a suitable hydrophobic tail 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 counterions 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 ranges from several hundred to several hundred thousand.

[0219] Cationic surfactants carry a positive charge on the main part of the molecular framework. Cationic surfactants are usually halides of molecules containing a hydrophobic chain and a cationic charge center (such as amines, quaternary ammonium, benzyalkonium, and alkylpyridinium ions).

[0220] On the other hand, the surfactant can be an amphoteric surfactant, which has positive (cationic) and negative (anionic) charges on the main molecular chain and has their relative counterions. The cationic part is based on primary, secondary, or tertiary amines or quaternary ammonium cations. The anionic part can be more variable and includes sulfonates, such as in sulfobetaines like CHAPS (3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate) and cocamidopropyl hydroxysulfobetaine. Betaines like cocamidopropyl betaine have carboxylic acid and ammonium. Some amphoteric surfactants can have phosphate anions with amines or ammonium, such as phospholipids like phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, and sphingomyelin.

[0221] Examples of surfactants also include, but are not limited to, sodium dodecyl sulfate, sodium lauryl sulfate, ammonium dodecyl 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 families and SURFYNOL manufactured by Air Products and Chemicals TM , DYNOL TM , Zetasperse TM , Nonidet TM and Tomadol TM various surfactants in the surfactant families. Suitable surfactants in the surfactant can also include polymers containing ethylene oxide (EO) and propylene oxide (PO) groups. An example of an EO-PO polymer is Tetronic TM 90R4.

[0222] When used, the amount of the surfactant is usually in the range of 0.0001% by weight to about 1.0% by weight relative to the total weight of the barrier CMP composition. When used, the preferred range is from about 0.010% by weight to about 0.1% by weight.

[0223] Chelating agent (optional)

[0224] Chelating agents can optionally be used in the compositions disclosed herein to enhance the affinity of chelating ligands for metal cations. Chelating agents can also be used to prevent the accumulation of metal ions on the polishing pad, which can lead to polishing pad contamination and instability of 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-diaminobenzenesulfonic 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 their salts; various amino acids and their derivatives such as glycine, serine, proline, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, ornithine, selenocysteine, tyrosine, sarcosine, N-bis(hydroxyethyl)glycine, N-tris(hydroxymethyl)glycine, acetylglutamine, n-acetylaspartic acid, acetylcarnitine, acetylcysteine, n-acetylglutamic acid, acetyll leucine, asivicin, s-adenosyl-l-homocysteine, agaritine, alanosine, aminohippuric acid, l-arginine ethyl ester, aspartame, asparagine glucosamine, benzyl mercapturic acid, ε-N-biotinyl-L-lysine, brinzolamide alanine ester, carboxymethylcysteine, n(6)-carboxymethyllysine, cargluonic acid, cilastatin, citalopram, coprine, dibromotyrosine, dihydroxyphenylglycine, eflornithine, fenclonine, 4-fluoro-l-threonine, n-formylmethionine, γ-l-glutamyl-l-cysteine, 4-(γ-glutamylamino)butyric acid, glutaurine, guanidinoacetic acid, hadacidin, hepapressin, lisinopril, lysyltetracycline, n-methyl-d-aspartic acid, n-methyl-l-glutamic acid, milacemide, nitrosoproline, nocardicin a, nopaline, octopine, ombrabulin, crown gall amino acid, anthranilic acid, oxaceprol, polylysine, remacemide, salicyluric acid, serino, stampidine, pyrenophorin, tetrazolylglycine, theophrine, thymectacin, tiopronin, tryptophan tryptophylquinone, valacyclovir, valganciclovir and phosphonic acid, and their derivatives such as, for example, octylphosphonic acid, aminobenzylphosphonic acid, and their combinations and salts.

[0225] In cases where chemical bonding of, for example, copper cations and tantalum cations is desired, chelating agents can be used to accelerate the dissolution of copper oxide and tantalum oxide to produce the desired removal rate of copper wires, vias or trenches, and barrier layers or barrier films.

[0226] When in use, the amount of the chelating agent preferably ranges from about 0.01 wt% to about 3.0 wt%, more preferably about 0.4 wt% to about 1.5 wt%, based on the total weight of the composition.

[0227] Biocide (optional)

[0228] The CMP formulations disclosed herein may also contain additives for controlling biological growth, such as biocides. Some additives for controlling 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 TM and NEOLENE TM product families and Preventol TM families from Lanxess.

[0229] Preferred biocides are isothiazolinone compounds such as methylisothiazolinone, methylchloroisothiazolinone, and benzisothiazolinone.

[0230] The CMP polishing composition optionally contains a biocide in the 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 the growth of bacteria and fungi during storage.

[0231] The compositions disclosed herein can be manufactured in concentrated form and subsequently diluted with deionized water at the time of use. Other components, such as, for example, oxidants, can be kept in concentrated form and added at the time of use to minimize incompatibilities between the components in concentrated form. The compositions disclosed herein can be manufactured from two or more components, which can be mixed prior to use.

[0232] Working Examples

[0233] General experimental procedures

[0234] Unless otherwise specified, all percentages are weight percentages.

[0235] Part I Synthesis of guanidine polymers and copolymers

[0236] Unless otherwise stated, all reagents and solvents were purchased from Sigma-Aldrich (Merck) at the highest commercial grade and used as received.

[0237] Characterization methods

[0238] 1H NMR spectra were recorded on a 500 MHz Bruker Avance II+ spectrometer using deuterated solvents from Sigma-Aldrich (Merck). Chemical shifts were reported in δ values (ppm) and calibrated according to the internal standard Si(OMe) 4 (0.00 ppm).

[0239] The polymers were analyzed by size exclusion chromatography (SEC) (flow rate: 0.5 mL / min) run at 40 °C in H 2 2O / MeOH / EtOAc (54 / 23 / 23, v / v / v) containing 10 mM sodium acetate. Measurements were performed on an Agilent 1260 HPLC equipped with a column set consisting of a PSS Novema pre-column and a PSS Novema MAX ultra-high column. At 50 °C, the samples were dissolved in the eluent containing 0.1% ethylene glycol as the internal standard. The average molar mass of the polymers was derived from the refractive index signal based on a poly(2-vinylpyridine) calibration curve.

[0240] Example 1

[0241] Synthesis of poly(vinylbenzyl-N-(bis(dimethylamino)methylene-N-methyl)methanaminium chloride):

[0242]

[0243] 1. Synthesis of monomers

[0244] (1) Synthesis of 1,1,2,3,3-pentamethylguanidine

[0245]

[0246] Tetramethylurea (CAS: 632-22-4, 4.6 g, 40 mmol) was dissolved in 50 mL of dichloroethane. Oxalyl chloride (CAS: 79-37-8, 8.2 g, 64.8 mmol) was added at room temperature and the mixed solution was heated at 60 °C for 2 h. After removing the solvent, the remaining yellow solid was dissolved in 20 mL of absolute ethanol, and a methylamine solution (CAS: 74-89-5, 33 wt% in absolute ethanol, 33 g, 355 mmol) was added dropwise at 0 °C. The reaction mixture was slowly warmed to room temperature and then refluxed for 4 h. The solvent was evaporated under vacuum, and the residue was treated with 30% aqueous sodium hydroxide solution. The organic layer was extracted with methyl tert-butyl ether (MTBE), dried over anhydrous magnesium sulfate, filtered and evaporated to give 4.6 g (89%) of a pale yellow oil.

[0247] 1 H NMR (500 MHz, CDCl 3 ) δ: 2.89 (s, 3H), 2.71 (s, 6H), 2.59 (s, 6H) ppm.

[0248] (2) Synthesis of N-(bis(dimethylamino)methylene)-N-methyl-1-(4-vinylphenyl)methanaminium chloride

[0249]

[0250] 4-Vinylbenzyl chloride (CAS: 1592-20-7, 4.5 g, 29.5 mmol) was dissolved in 50 mL of acetonitrile. 1,1,1,2,3,3-Pentamethylguanidine (4.2 g, 32.3 mmol) was added, and the reaction mixture was stirred under reflux for 18 h. The product was precipitated by adding THF to the cooled solution. The solid was filtered, washed twice with THF and dried under vacuum to give a white solid (7.4 g, 89% yield).

[0251] 1 H NMR (500 MHz, DMSO-d 6 ): δ = 7.56 - 7.46 (m, 2H), 7.39 - 7.28 (m, 2H), 6.76 (dd, J = 17.7, 10.9 Hz, 1H), 5.87 (dd, J = 17.6, 1.0 Hz, 1H), 5.30 (dd, J = 11.0, 0.9 Hz, 1H), 4.51 (d, J = 13.9 Hz, 1H), 4.22 (d, J = 13.9 Hz, 1H), 3.01 (s, 3H), 2.91 (s, 6H), 2.77 (s, 3H), 2.70 (s, 3H) ppm.

[0252] 2. Polymerization

[0253]

[0254] Charge a Schlenk flask with guanidine-containing styrene (6 g, 21.3 mmol), AIBN (CAS: 78-67-1, 3.7 mg, 0.023 mmol), and 2-(dodecylthiocarbamothioylthio)-2-methylpropanoic acid (DDMAT, CAS: 461642-78-4, 26 mg, 0.07 mmol). Dissolve the mixture in acetonitrile / water (50 mL, 1:1 v / v), purge with Ar for 30 min, and then heat at 65 °C for 18 h. Cool the solution to room temperature, remove the acetonitrile, and dissolve the residue in 10 mL of dichloromethane. Finally, precipitate the polymer by adding 100 mL of THF, wash twice with THF, and dry in vacuo to obtain 5.5 g of a yellow solid (92% yield).

[0255] 1 H NMR (500 MHz, DMSO-d 6 ) δ: 7.09 (broad s), 6.33 (broad s), 4.33 (broad s), 2.94 (broad s), 2.51 (broad s), 1.30 (broad s) ppm.

[0256] SEC: Mn: 22.6 kDa; Mw: 44.6 kDa; PDI: 2.0.

[0257] Example 2

[0258] Synthesis of ammonium-based material (prior art)

[0259] Synthesize poly(tributyl-(4-vinylbenzyl)ammonium chloride) using the method described in Biomacromolecules (2012), 13(1), 231-238.

[0260]

[0261] 1 H NMR (500 MHz, methanol-d 4 ) δ: 7.32 (broad s), 6.64 (broad s), 4.62 (broad s), 3.21 (broad s), 1.81 (broad s), 1.40 (broad s), 1.08 - 1.00 (broad m) ppm.

[0262] SEC: Mn: 22.6 kDa; Mw: 44.6 kDa; PDI: 2.0.

[0263] Example 3

[0264] Synthesis of phosphonium-based material (prior art)

[0265] Synthesize poly(tributyl(4-vinylbenzyl)phosphonium chloride) using the method described in U.S. Provisional Application 63 / 209,306 filed on June 10, 2021.

[0266]

[0267] 1 H NMR (500 MHz, methanol-d 4 ) δ: 7.29 (broad s), 6.54 (broad s), 4.04 (broad s), 2.32 (broad s), 1.49 (broad s), 0.96 (broad s) ppm.

[0268] SEC: Mn: 90 kDa; Mw: 352 kDa; PDI: 3.9.

[0269] Example 4

[0270] Synthesis of imidazole-based materials (prior art)

[0271] Poly(vinylbenzyl-1-butyl-1H-imidazol-3-ium) chloride was synthesized using the method described in U.S. Provisional Application 63 / 191,047 filed on May 20, 2021.

[0272]

[0273] 1 H NMR (500 MHz, methanol-d 4 ) δ: 9.52 (broad s), 7.70 (broad s), 7.32 (broad s), 6.42 (broad s), 5.52 (broad s), 4.29 (broad s), 2.04 - 1.71 (broad m), 1.37 (broad s), 0.97 (broad s) ppm.

[0274] SEC: Mn: 35 kDa; Mw: 106 kDa; PDI: 3.0.

[0275] Example 5

[0276] Synthesis of poly(3-acrylamido-N-(bis(dimethylamino)methylene-N-methylpropan-1-aminium bromide)):

[0277]

[0278] 1. Synthesis of monomers

[0279] (1) Synthesis of N-(3-bromopropyl)-2-propenamide

[0280]

[0281] 3-Bromopropylamine hydrobromide (CAS: 5003-71-4, 9.9 g, 45 mmol) was dissolved in 150 mL of chloroform and mixed with triethylamine (TEA, CAS: 121-44-8, 14 mL, 100 mmol) and 4-(dimethylamino)pyridine (DMAP, CAS: 1122-58-3, 288 mg, 2.3 mmol). The solution was cooled to 0 °C and acryloyl chloride (CAS: 814-68-6, 4.2 mL, 50 mmol) was added dropwise. The mixture was stirred at room temperature for 4 h and washed with saturated NaHCO 3 (2 x 100 mL) and water (2 x 100 mL), dried over MgSO 4 , filtered and the solvent was removed (6.45 g, 75% brown oil) after adding 2,6-di-tert-butyl-4-methylphenol (BHT, CAS: 128-37-0, 6.3 mg) as a stabilizer.

[0282] 1 1H NMR (500 MHz, CDCl 3 ) δ: 6.30 (d, J = 16.8 Hz, 1H), 6.15 (d, J = 10.0 Hz, 1H), 6.07 (s, 1H), 6.66 (dd, J = 16.8, 10.0 Hz, 1H), 3.51–3.41 (m, 4H), 2.17–2.09 (m, 2H) ppm.

[0283] (2) Synthesis of 3-acrylamido-N-(bis(dimethylamino)methylene)-N-methylpropan-1-aminium bromide

[0284]

[0285] N-(3-Bromopropyl)-2-propenamide (CAS: 108595-90-0, 5 g, 26 mmol) was dissolved in 50 mL of acetonitrile. 1,1,2,3,3-Pentamethylguanidine (3.7 g, 28.5 mmol) was added and the reaction mixture was stirred at room temperature overnight. The product was precipitated by adding THF to the solution. The solid was filtered, washed twice with THF and dried in vacuo to give a yellow solid (5.7 g, 68% yield).

[0286] 2. Polymerization

[0287]

[0288] Charge a Schlenk flask with guanidine-containing acrylamide (5 g, 15.6 mmol) and AIBN (CAS: 78-67-1, 3.7 mg, 0.023 mmol). Dissolve the mixture in acetonitrile / water (30 mL, 1:1 v / v), purge with Ar for 30 min and heat at 70 °C for 18 h. Cool the solution to room temperature, remove the acetonitrile, and dissolve the residue in 10 mL of dichloromethane. Finally, precipitate the polymer by adding 100 mL of THF, wash twice with THF and dry in vacuo to obtain 4.8 g of a yellow oil (96% yield).

[0289] Example 6

[0290] Synthesis of poly(N-(1,3-dimethylimidazolidin-2-ylidene)-N-methyl-1-(4-vinylphenyl)methanaminium chloride):

[0291]

[0292] 1. Synthesis of monomers

[0293] (1) Synthesis of N-1,3-trimethylimidazolidin-2-imine

[0294]

[0295] 1,3-Dimethyl-2-imidazolidinone (CAS: 80-73-9, 4.6 g, 40 mmol) is dissolved in 50 mL of dichloroethane. Oxalyl chloride (CAS: 79-37-8, 8.2 g, 64.8 mmol) is added at room temperature and the solution is heated at 60 °C for 2 h. After removing the solvent, the remaining yellow solid is dissolved in 20 mL of absolute ethanol, and a methylamine solution (CAS: 74-89-5, 33 wt% in absolute ethanol, 33 g, 355 mmol) is added dropwise at 0 °C. The reaction mixture is slowly warmed to room temperature and then refluxed for 4 h. The solvent is evaporated under vacuum, and the residue is treated with 30% aqueous sodium hydroxide solution. The organic layer is extracted with MTBE, dried over anhydrous magnesium sulfate, filtered and evaporated to obtain 4.6 g (90%) of a pale yellow oil.

[0296] (2) Synthesis of N-(1,3-dimethylimidazolidin-2-ylidene)-N-methyl-1-(4-vinylphenyl)methanaminium chloride

[0297]

[0298] 4-Vinylbenzyl chloride (CAS: 1592-20-7, 4.5 g, 29.5 mmol) was dissolved in 50 mL of acetonitrile. N-1,3-Trimethylimidazolidin-2-imine (4.1 g, 32.3 mmol) was added, and the reaction mixture was stirred under reflux for 18 h. The product was precipitated by adding THF to the cooled solution. The solid was filtered, washed twice with THF and dried in vacuo to give a white solid (5.8 g, 70% yield).

[0299] 2. Polymerization:

[0300]

[0301] A Schlenk flask was charged with guanidine-containing styrene (6 g, 21.3 mmol), AIBN (CAS: 78-67-1, 3.7 mg, 0.023 mmol) and 2-(dodecylthiocarbonothioylthio)-2-methylpropanoic acid (DDMAT, CAS: 461642-78-4, 26 mg, 0.07 mmol). The mixture was dissolved in acetonitrile / water (50 mL, 1:1 v / v), purged with Ar for 30 min, and then heated at 65 °C for 18 h. The solution was cooled to room temperature, the acetonitrile was removed, and the residue was dissolved in 10 mL of dichloromethane. Finally, the polymer was precipitated by adding 100 mL of THF, washed twice with THF and dried in vacuo to give 5.5 g of a yellow solid (92% yield).

[0302] Example 7

[0303] Synthesis of poly(1-(bis(dimethylamino)methylene)-3,4-ethylenepyrrolidin-1-ium bromide):

[0304]

[0305] 1. Synthesis of monomers

[0306] (1) Synthesis of 2-allyl-1,1,3,3-tetramethylguanidine

[0307]

[0308] Tetramethylurea (CAS: 632-22-4, 4.6 g, 40 mmol) was dissolved in 50 mL of dichloroethane. Oxalyl chloride (CAS: 79-37-8, 8.2 g, 64.8 mmol) was added at room temperature, and the solution was heated at 60 °C for 2 h. After removing the solvent, the remaining yellow solid was dissolved in 20 mL of absolute ethanol, and allylamine (CAS: 107-11-9, 20 g, 355 mmol) was added dropwise at 0 °C. The reaction mixture was slowly warmed to room temperature and then refluxed for 4 h. The solvent was evaporated in vacuo, and the residue was treated with 30% aqueous sodium hydroxide solution. The organic layer was extracted with MTBE, dried over anhydrous magnesium sulfate, filtered and evaporated to give 5 g (80.6%) of a pale yellow oil.

[0309] (2) Synthesis of N-(allyl-N-(bis(dimethylamino)methylene)prop-2-en-1-ammonium bromide

[0310]

[0311] Allyl bromide (CAS: 106-95-6, 3.6 g, 29.5 mmol) was dissolved in 50 mL of acetonitrile. 2-Allyl-1,1,3,3-tetramethylguanidine (5.0 g, 32.3 mmol) was added, and the reaction mixture was stirred at room temperature for 18 h. The product was precipitated by adding THF to the solution. The solid was filtered, washed twice with THF and dried in vacuo to give a white solid (7.4 g, 90% yield).

[0312] 2. Polymerization

[0313]

[0314] N-(allyl-N-(bis(dimethylamino)methylene)prop-2-en-1-ammonium bromide (5.9 g, 21.3 mmol), AIBN (CAS: 78-67-1, 3.7 mg, 0.023 mmol) and 2-(dodecylthiocarbonothioylthio)-2-methylpropanoic acid (DDMAT, CAS: 461642-78-4, 26 mg, 0.07 mmol) were added to a Schlenk flask. The mixture was dissolved in acetonitrile / water (50 mL, 1:1 v / v), purged with Ar for 30 min and then heated at 65 °C for 18 h. The solution was cooled to room temperature, the acetonitrile was removed, and the residue was dissolved in 10 mL of dichloromethane. Finally, the polymer was precipitated by adding 100 mL of THF, washed twice with THF and dried in vacuo to give 4.5 g of a yellow oil (76% yield).

[0315] Partial IICMP experiment

[0316] 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.

[0317] The polishing composition uses the guanidine polymer or copolymer synthesized in Part I.

[0318] In the examples presented below, CMP experiments were conducted using the procedures and experimental conditions given below.

[0319] Parameters:

[0320] Å - length unit

[0321] BP: Back pressure, in psi

[0322] CMP: Chemical mechanical planarization = Chemical mechanical polishing

[0323] CS: Carrier speed

[0324] DF: Downward force: Pressure applied during CMP, in psi

[0325] min: Minute

[0326] ml: Milliliter

[0327] mV: Millivolt

[0328] psi: Pounds per square inch

[0329] PS: Platen rotation speed of the polishing equipment, in rpm (revolutions per minute)

[0330] SF: Polishing composition flow rate, ml / min

[0331] TEOS: Silicon oxide film using tetraethyl orthosilicate as a precursor by chemical vapor deposition (CVD)

[0332] wt%: Weight percentage (of the listed components)

[0333] Removal rate (RR) = (Film thickness before polishing - Film thickness after polishing) / Polishing time.

[0334] Removal rate and selectivity

[0335] Tungsten removal rate: Tungsten removal rate measured at a pressure of 2.5 psi in the CMP equipment.

[0336] TEOS removal rate: TEOS removal rate measured at a given downward pressure. The downward pressure of the CMP equipment is 2.5 psi.

[0337] SiN removal rate: The SiN removal rate measured at a given down pressure. The down pressure of the CMP equipment is 2.5 psi.

[0338] TiN removal rate: The TiN removal rate measured at a given down pressure. The down pressure of the CMP equipment is 2.5 psi.

[0339] The CMP equipment used in the examples is AMAT 200mm It is manufactured by Applied Materials, Inc., 3050 Bowers Avenue, Santa Clara, California, 95054. The IC1010 polishing pad provided by Dow Chemicals is used on the platen for polishing research.

[0340] 200 mm diameter silicon wafers coated with tungsten film, TEOS film, SiN film or tungsten-containing SKW patterned structures are obtained from SKW Associate, Inc., 2920 Scott Blvd, Santa Clara, CA 95054. The polishing time for the blanket film is one minute. The tungsten removal rate is measured using sheet resistance measurement techniques. The removal of TEOS is measured using optical techniques. The patterned wafers are polished on an Ebara polishing machine based on eddy current technology for a period of time. The polishing time of the patterned wafers exceeds the endpoint determined by the eddy current endpoint technology by 15 seconds. The patterned wafers are analyzed using a KLA Tencor P15 profiler (large feature size) or an AFM tool (small feature size).

[0341] Polishing is carried out using a platen speed of 111 RPM, a carrier speed of 113 RPM, a slurry flow rate of 200 ml / min and a down pressure of 2.5 psi.

[0342] During polishing, the substrate (e.g., blanket W or patterned W wafer) is placed face down on the polishing pad, which is fixedly attached to the rotatable platen of the CMP polishing machine. In this way, the substrate to be polished and planarized is in direct contact with the polishing pad. The substrate is held in place using a wafer carrier system or a polishing head, and a downward pressure is applied to the back of the substrate while the platen and the substrate are rotating during the CMP process. During the CMP process, the polishing composition (slurry) is applied (usually continuously) to the pad to effectively remove material and planarize the substrate.

[0343] The PL-2C silica abrasive was purchased from Fuso Chemical Company (Ogura Bldg. 6-6, Nihonbashi-kobuna-cho, Chuo-ku, Tokyo, Japan 103-0024). Unless otherwise specified, all reagents and solvents were purchased from Sigma-Aldrich (Merck) at the highest commercial grade and used as received.

[0344] In the following working examples, a base (matrix) CMP slurry was prepared with 0.01 wt% iron nitrate (iron(III) nitrate), 0.08 wt% malonic acid (stabilizer), 2.0 wt% hydrogen peroxide, 0.1 wt% glycine, and 0.25 wt% Fuso PL-2C silica particles in water, and the pH was adjusted to 2.3 with nitric acid.

[0345] The effects of the guanidine-based polymers on the tungsten removal rate, erosion, and dishing were tested.

[0346] Example 1

[0347] A working CMP slurry was prepared by adding the guanidine-based polymers and copolymers described in Part I to the base CMP slurry.

[0348] The tungsten, TEOS, and SiN removal rates using the guanidine-based polymer (Example 1) were tested relative to the base slurry without added polymer and relative to other existing cationic polyelectrolytes (Examples 2-4).

[0349] The results are shown in Table 1.

[0350] Table 1. Film removal rates and film selectivities

[0351]

[0352] Compared to the base slurry, all examples containing polycationic polymers improved the selectivity between the tungsten removal rate relative to TEOS and / or the tungsten removal rate relative to SiN under the stated conditions.

[0353] Testing the tungsten dishing under the same conditions as the baseline slurry test: On different arrays including 50×50 micron arrays (tungsten line width / dielectric line width / grooves separated by spacers in microns) (50 / 50μm), 1×1 micron (1 / 1μm), 0.5×0.5 micron (0.5 / 0.5μm), 0.25×0.25 micron (0.25 / 0.25μm), and 0.18×0.18 micron arrays (0.18 / 0.18μm), when the wafer is re-polished for 15 seconds or the over-polish (OP) time after detecting the pattern wafer polish endpoint by using eddy current measurement (W line dishing data is shown in Table 2; the baseline slurry value is the average of 8 different measurements).

[0354] Table 2. W line dishing

[0355]

[0356] For wider lines, the dishing of the lines generally increases. The negative value of the W line dishing basically means that no W line dishing (protrusion of the W line) is observed.

[0357] In a typical tungsten CMP process, it is desired that the tungsten dishing for wider line features is less than 1500 angstroms

[0358] Testing the erosion under the same conditions as the baseline slurry test: For various formulations, on 7 / 3μm, 1 / 1μm, 0.5 / 0.5μm, 0.25 / 0.25μm, 0.18 / 0.18μm arrays, with 20% over-polish (Table 3).

[0359] Table 3. Erosion

[0360]

[0361]

[0362] The erosion of the arrays generally increases with the increase in the pattern density. The negative value of the erosion describes the protrusion. Basically, no erosion is observed.

[0363] In a typical tungsten CMP process, it is desired to have erosion on high-density features (such as 70% and 90% density),

[0364] As shown in Tables 2 and 3, the working CMP slurry with a small amount of synthetic guanidine polymers and copolymers (about 15 ppm) provides a high tungsten removal rate, and the increase in the concentration inhibits the effect on the tungsten removal.

[0365] As can be seen from the results given separately in Tables 2 and 3, the use of guanidine polymers can reduce both erosion and dents (high-density features). Other cationic counterparts did not show such beneficial properties. In summary, all cationic polymers used sharply increased the selectivity of the corresponding slurries, but only the guanidine materials additionally showed a beneficial effect on the erosion and dent effects.

[0366] Although the principles of the present invention have been described above in connection with preferred embodiments, it should be clearly understood that such description is merely exemplary and not a limitation on the scope of the present invention. On the contrary, the following detailed description of 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 can be made to the functions and arrangements of the elements without departing from the spirit and scope of the present invention as set forth in the appended claims.

Claims

1. A guanidine polymer or copolymer comprising more than one monomer containing at least one guanidine group having the following structure: Wherein: P 1 represents a polymerizable group, Sp 1 represents a spacer group; preferably Sp 1 has a substituted or unsubstituted aliphatic moiety having single bonds at both ends; R 1 is H or a substituted or unsubstituted aliphatic moiety, wherein CH 2 may be replaced by O, S or N in a manner that no heteroatoms are linked to each other; preferably R 1 is CH 3 or CH 2 -CH 3 ; R 2 is H or a substituted or unsubstituted aliphatic moiety; preferably R 2 is H, CH 3 or CH 2 -CH 3 ; R 3 is H or a substituted or unsubstituted aliphatic moiety; where two R 3 groups may form a bridge between the nitrogen atoms to form a five-membered, six-membered or seven-membered ring; And preferably R 3 is H, CH 3 , or two R 3 groups form a bridge between the nitrogen atoms to form a five-membered ring; And X - represents an anionic counterion.

2. The guanidine polymer or copolymer according to claim 1, wherein the polymerizable group P 1 is selected from styrene (or vinylbenzene), acrylate or methacrylate, vinyl ether, allyl ether, acrylamide or methacrylamide, ethylene oxide, propylene oxide, maleimide, siloxane, norbornene, a group containing a C═C double bond, and combinations thereof; and preferably the polymerizable group P 1 is a group containing a C═C double bond.

3. A guanidine polymer or copolymer comprising more than one repeating unit having structure (A): Wherein: n represents the number of repeating units, and 1 < n < 4000, 50 < n < 1500 or 75 < n < 1000; R 1 is H or a substituted or unsubstituted aliphatic moiety; and preferably R 1 is H, CH 3 or CH 2 -CH 3 ; R 2 is H or a substituted or unsubstituted aliphatic moiety; where two R 2 groups may form a bridge between the nitrogen atoms to form a five-membered, six-membered or seven-membered ring; And preferably R 3 is H, CH 3 , or two R 2 groups form a bridge between the nitrogen atoms, thereby constructing a five-membered ring; And X - represents an anionic counterion.

4. The guanidine polymer or copolymer according to any one of claims 1-3, wherein the anionic counterion X - is selected from halide ions (F - , Cl - , Br - or I - ), BF 4 - , PF 6 - , carboxylate, malonate, citrate, carbonate, fumarate, MeOSO 3 - , MeSO 3 - , CF 3 COO - , CF 3 SO 3 - , nitrate and sulfate, where Me is methyl.

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

6. The guanidine polymer or copolymer according to any one of claims 1 - 5, wherein the copolymer has block copolymer characteristics.

7. The guanidine polymer or copolymer according to any one of claims 1 - 6, wherein the guanidine polymer is poly(vinylbenzyl - N - (bis(dimethylamino)methylene - N - methyl)methanaminium chloride), poly(3 - acrylamido - N - (bis(dimethylamino)methylene - N - methylpropane - 1 - ammonium bromide); poly(N - (1,3 - dimethylimidazolidin - 2 - ylidene)-N - methyl - 1 - (4 - vinylphenyl)methanaminium chloride); or poly(1 - (bis(dimethylamino)methylene)-3,4 - ethylenepyrrolidin - 1 - ium bromide).

8. The guanidine polymer or copolymer according to any one of claims 1 - 7, wherein the guanidine polymer or copolymer is water - soluble.

9. A chemical - mechanical planarization composition comprising the guanidine polymer or copolymer according to any one of claims 1 - 8.

10. A chemical - mechanical planarization composition comprising: Abrasive; The guanidine polymer or copolymer according to any one of claims 1 - 8; Water; and optionally Activator; Oxidizing agent; Corrosion inhibitor; Dishing reducer; Stabilizer; and pH regulator.

11. The chemical - mechanical planarization composition according to claim 10, wherein the abrasive is selected from inorganic oxide particles, inorganic oxide particles coated with metal oxides, organic polymer particles, organic polymer particles coated with metal oxides, surface - modified abrasive particles, and combinations thereof, and the abrasive is in the range of 0.01 wt% - 30 wt%, 0.05 wt% - 20 wt%, 0.01 wt% - 10 wt% or 0.1 wt% - 2 wt%.

12. The chemical - mechanical planarization composition according to any one of claims 10 - 11, wherein the guanidine polymer or copolymer is in the range of 0.00001 wt% - 1.0 wt%, 0.0001 wt% - 0.5 wt%, 0.0002 wt% - 0.1 wt% or 0.0005 wt% - 0.05 wt%.

13. The chemical - mechanical planarization composition according to any one of claims 10 - 12, wherein the abrasive is silica particles.

14. The chemical mechanical planarization composition according to any one of claims 10-13, wherein the oxidizing agent is selected from peroxides, which are selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted perbutyric acid, hydroperoxy-acetaldehyde, potassium periodate, and ammonium monopersulfate; and non-peroxides, which are selected from ferrous nitrite, KClO 4 , KBrO 4 and KMnO 4 ; and combinations thereof; and the oxidizing agent is in the range of 0.01 wt% - 30 wt%, 0.1 wt% - 20 wt% or 0.5 wt% - 10 wt%.

15. The chemical mechanical planarization composition according to any one of claims 10-14, wherein the activator is selected from (1) inorganic oxide particles coated with a transition metal on the surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) soluble catalysts selected from iron(III) nitrate, ammonium iron(III) oxalate trihydrate, iron(III) citrate monohydrate, iron(III) acetylacetonate, and sodium iron(III) ethylenediaminetetraacetate hydrate; (3) metal compounds having multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, and V; and combinations thereof; and the activator is in the range of 0.00001 wt% - 5.0 wt%, 0.0001 wt% - 2.0 wt%, 0.0005 wt% - 1.0 wt%, or 0.001 wt% to 0.5 wt%.

16. The chemical mechanical planarization composition according to any one of claims 10-15, 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) ester, and combinations thereof; and the corrosion inhibitor is in the range of less than 1.0 wt%, less than 0.5 wt%, or less than 0.25 wt%.

17. The chemical mechanical planarization composition according to any one of claims 10-16, wherein the pH regulator 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.

18. The chemical mechanical planarization composition according to any one of claims 10-17, wherein the pH of the composition is 1-14, 1-7, 1-6, or 1.5-4.

19. The chemical mechanical planarization composition according to any one of claims 10 - 18, wherein the dishing reducer is selected from sarcosinates and related carboxylic acid compounds; hydrocarbon - substituted sarcosinates; amino acids; organic polymers and copolymers having molecules with ethylene oxide repeat units, such as polyethylene oxide (PEO); ethoxylated surfactants; nitrogen - containing heterocycles without N - H bonds; sulfides; oxazolidines or mixtures of functional groups in a compound; nitrogen - containing compounds having three or more carbon atoms that form alkylammonium ions; aminoalkyls having three or more carbon atoms; polymer corrosion inhibitors having repeating groups containing at least one nitrogen - containing heterocycle or tertiary or quaternary nitrogen atoms; polycationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; and sulfonic acid polymers; and combinations thereof; 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%.

20. The chemical mechanical planarization composition according to any one of claims 10 - 19, wherein the stabilizer is selected from adipic acid, phthalic acid, citric acid, malonic acid, phthalic acid; phosphoric acid; substituted or unsubstituted phosphonic acids; nitriles; and combinations thereof; and the stabilizer is in the range of 0.0001 to 5 wt%, 0.00025 to 2 wt% or 0.0005 to 1 wt%.

21. The chemical mechanical planarization composition according to any one of claims 10 - 20, wherein the chemical mechanical planarization composition comprises silica particles or surface - modified silica particles; the guanidine polymer or copolymer selected from poly(vinylbenzyl - N - (bis(dimethylamino)methylene - N - methyl)methanaminium chloride), poly(3 - acrylamido - N - (bis(dimethylamino)methylene - N - methylpropane - 1 - ammonium bromide), poly(N - (1,3 - dimethylimidazolidin - 2 - ylidene)-N - methyl - 1 - (4 - vinylphenyl)methanaminium chloride), poly(1 - (bis(dimethylamino)methylene)-3,4 - ethylenepyrrolidin - 1 - ium bromide) and combinations thereof; iron(III) nitrate; malonic acid; hydrogen peroxide; and water; and the pH of the composition is 1.5 - 4.

22. A polishing method for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten - containing surface, which comprises the following steps: a) providing a polishing pad; b) providing a chemical mechanical planarization composition comprising: abrasive; the guanidine polymer or copolymer according to any one of claims 1 - 8; water; and optionally activator; oxidizing agent; corrosion inhibitor; dishing reducer; stabilizer; and pH regulator; and c) polishing the at least one tungsten - containing surface with the chemical mechanical planarization composition.

23. The polishing method according to claim 22, wherein the abrasive is selected from inorganic oxide particles, inorganic oxide particles coated with metal oxides, organic polymer particles, organic polymer particles coated with metal oxides, and combinations thereof; and the abrasive is in the range of 0.01 wt% - 30 wt%, 0.05 wt% - 20 wt%, 0.01 wt% - 10 wt% or 0.1 wt% - 2 wt%.

24. The polishing method according to any one of claims 22 - 23, wherein the guanidine polymer or copolymer is in the range of 0.00001 wt% - 1.0 wt%, 0.0001 wt% - 0.5 wt%, 0.0002 wt% - 0.1 wt% or 0.0005 wt% - 0.05 wt%.

25. The polishing method according to any one of claims 22 - 24, wherein the abrasive is silica particles or surface - modified silica particles.

26. The polishing method according to any one of claims 22-25, wherein the oxidizing agent is selected from peroxides, which are selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted peroxybutyric acid, hydroperoxy-acetaldehyde, potassium periodate, and ammonium monopersulfate; and non-peroxides, which are selected from ferrous nitrite, KClO 4 , KBrO 4 and KMnO 4 ; and combinations thereof; and the oxidizing agent is in the range of 0.01 wt% - 30 wt%, 0.1 wt% - 20 wt% or 0.5 wt% - 10 wt%.

27. The polishing method according to any one of claims 22 - 26, wherein the activator is selected from (1) inorganic oxide particles coated with a transition metal on the surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) soluble catalysts selected from iron(III) nitrate, ammonium iron(III) oxalate trihydrate, iron(III) citrate monohydrate, iron(III) acetylacetonate, and sodium iron(III) ethylenediaminetetraacetate hydrate; (3) metal compounds having multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, and V; and combinations thereof; and the activator is in the range of 0.00001 wt% - 5.0 wt%, 0.0001 wt% - 2.0 wt%, 0.0005 wt% - 1.0 wt% or 0.001 wt% to 0.5 wt%.

28. The polishing method according to any one of claims 22 - 27, 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) ester, and combinations thereof; and the corrosion inhibitor is in the range of less than 1.0 wt%, less than 0.5 wt% or less than 0.25 wt%.

29. The polishing method according to any one of claims 22-28, wherein the pH regulator 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.

30. The polishing method according to any one of claims 22-29, wherein the pH of the composition is 1-14, 1-7, 1-6, or 1.5-4.

31. The polishing method according to any one of claims 22-30, wherein the dishing reducer is selected from sarcosinates and related carboxylic acid compounds; hydrocarbon-substituted sarcosinates; amino acids; organic polymers and copolymers having molecules with ethylene oxide repeat units such as polyethylene oxide (PEO); ethoxylated surfactants; nitrogen-containing heterocycles without nitrogen-hydrogen bonds; sulfides; oxazolidines, or mixtures of functional groups in a compound; nitrogen-containing compounds having three or more carbon atoms that form alkylammonium ions; aminoalkyls having three or more carbon atoms; polymer corrosion inhibitors having repeating groups containing at least one nitrogen-containing heterocycle or tertiary or quaternary nitrogen atoms; polycationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; and sulfonic acid polymers; and combinations thereof; 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%.

32. The polishing method according to any one of claims 22-31, wherein the stabilizer is selected from adipic acid, phthalic acid, citric acid, malonic acid, phthalic acid; phosphoric acid; substituted or unsubstituted phosphonic acids; nitriles; and combinations thereof; and the stabilizer is in the range of 0.0001 to 5 wt%, 0.00025 to 2 wt%, or 0.0005 to 1 wt%.

33. The polishing method according to any one of claims 22-32, wherein the chemical mechanical planarization composition comprises silica particles or surface-modified silica particles; the guanidine polymer or copolymer selected from poly(vinylbenzyl-N-(bis(dimethylamino)methylene-N-methyl)methanaminium chloride), poly(3-acrylamido-N-(bis(dimethylamino)methylene-N-methylpropane-1-ammonium bromide), poly(N-(1,3-dimethylimidazolidin-2-ylidene)-N-methyl-1-(4-vinylphenyl)methanaminium chloride), poly(1-(bis(dimethylamino)methylene)-3,4-ethylenepyrrolidin-1-ium bromide), and combinations thereof; iron(III) nitrate; malonic acid; hydrogen peroxide; and water; and the pH of the composition is 1.5-4.

34. A system for chemical mechanical planarization of a semiconductor substrate comprising at least one tungsten-containing surface, which comprises: a) a polishing pad; and b) a chemical mechanical planarization composition, which comprises: Abrasive; The guanidine polymer or copolymer according to any one of claims 1-8; Water; and optionally Activator; Oxidizing agent; Corrosion inhibitor; Dent reducer; Stabilizer; and pH regulator; and wherein the at least one tungsten-containing surface is in contact with the polishing pad and the chemical mechanical planarization composition.

35. The system according to claim 34, wherein the chemical mechanical planarization composition has an abrasive selected from inorganic oxide particles, metal oxide-coated inorganic oxide particles, organic polymer particles, metal oxide-coated organic polymer particles, and combinations thereof, and ranges from 0.01 wt% - 30 wt%, 0.05 wt% - 20 wt%, 0.01 wt% - 10 wt%, or 0.1 wt% - 2 wt%.

36. The system according to any one of claims 34-35, wherein the guanidine polymer or copolymer ranges from 0.00001 wt% - 1.0 wt%, 0.0001 wt% - 0.5 wt%, 0.0002 wt% - 0.1 wt%, or 0.0005 wt% - 0.05 wt%.

37. The system according to any one of claims 34-36, wherein the abrasive is silica particles or surface-modified silica particles.

38. The system according to any one of claims 34-37, wherein the oxidizing agent is selected from peroxides, which are selected from hydrogen peroxide, urea peroxide, performic acid, peracetic acid, perpropionic acid, substituted or unsubstituted perbutyric acid, hydroperoxy-acetaldehyde, potassium periodate, and ammonium monopersulfate; and non-peroxides, which are selected from ferrous nitrite, KClO 4 , KBrO 4 and KMnO 4 ; and combinations thereof; and the oxidizing agent is in the range of 0.01 wt% - 30 wt%, 0.1 wt% - 20 wt% or 0.5 wt% - 10 wt%.

39. The system according to any one of claims 34-38, wherein the activator is selected from (1) inorganic oxide particles coated with a transition metal on the surface; and the transition metal is selected from Fe, Cu, Mn, Co, Ce, and combinations thereof; (2) soluble catalysts selected from iron(III) nitrate, ammonium iron(III) oxalate trihydrate, iron(III) citrate monohydrate, iron(III) acetylacetonate, and ethylenediaminetetraacetic acid, and iron(III) sodium hydrate; (3) metal compounds having multiple oxidation states selected from Ag, Co, Cr, Cu, Fe, Mo, Mn, Nb, Ni, Os, Pd, Ru, Sn, Ti, and V; and combinations thereof; and the activator ranges from 0.00001 wt% - 5.0 wt%, 0.0001 wt% - 2.0 wt%, 0.0005 wt% - 1.0 wt%, or 0.001 wt% to 0.5 wt%.

40. The system according to any one of claims 34-39, 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 triazinethioltriol, pyrazoles, imidazoles, isocyanurates such as 1,3,5-tris(2-hydroxyethyl) ester, and combinations thereof; and the corrosion inhibitor ranges from less than 1.0 wt%, less than 0.5 wt%, or less than 0.25 wt%.

41. The system according to any one of claims 34 - 40, wherein the pH regulator 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.

42. The system according to any one of claims 34 - 41, wherein the pH of the composition is 1 - 14, 1 - 7, 1 - 6, or 1.5 - 4.

43. The system according to any one of claims 34 - 42, wherein the dent reducer is selected from sarcosinates and related carboxylic acid compounds; hydrocarbon - substituted sarcosinates; amino acids; organic polymers and copolymers having molecules with ethylene oxide repeat units such as polyethylene oxide (PEO); ethoxylated surfactants; nitrogen - containing heterocycles without N - H bonds; sulfides; oxazolidines, or mixtures of functional groups in a compound; nitrogen - containing compounds having three or more carbon atoms that form alkylammonium ions; aminoalkyls having three or more carbon atoms; polymeric corrosion inhibitors having repeating groups containing at least one nitrogen - containing heterocycle or tertiary or quaternary nitrogen atoms; polycationic amine compounds; cyclodextrin compounds; polyethyleneimine compounds; glycolic acid; chitosan; sugar alcohols; polysaccharides; alginate compounds; and sulfonic acid polymers; and combinations thereof; and the dent 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%.

44. The system according to any one of claims 34 - 43, wherein the stabilizer is selected from adipic acid, phthalic acid, citric acid, malonic acid, phthalic anhydride; phosphoric acid; substituted or unsubstituted phosphonic acids; nitriles; and combinations thereof; and the stabilizer is in the range of 0.0001 to 5 wt%, 0.00025 to 2 wt%, or 0.0005 to 1 wt%.

45. The system according to any one of claims 34 - 44, wherein the chemical - mechanical planarization composition comprises silica particles or surface - modified silica particles; iron(III) nitrate; malonic acid; hydrogen peroxide; the guanidine polymer or copolymer selected from poly(vinylbenzyl - N - (bis(dimethylamino)methylene - N - methyl)methanaminium chloride), poly(3 - acrylamido - N - (bis(dimethylamino)methylene - N - methylpropane - 1 - ammonium bromide), poly(N - (1,3 - dimethylimidazolidin - 2 - ylidene)-N - methyl - 1 - (4 - vinylphenyl)methanaminium chloride), poly(1 - (bis(dimethylamino)methylene)-3,4 - ethylenepyrrolidin - 1 - ium bromide), and combinations thereof; and water; the pH of the composition is 1.5 - 4.

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