Post-chemical mechanical polishing cleaning composition

Abstract

The present application relates to a post-chemical mechanical polishing cleaning composition. The invention provides a removal composition and method for cleaning ceria particles and post-chemical mechanical polishing (CMP) contaminants from a microelectronic device having the same thereon. The composition achieves highly effective removal of the ceria particles and CMP byproduct contaminant materials from the surface of the microelectronic device without damaging low-k dielectric materials, silicon nitride materials, or tungsten-containing materials.

Description

[0001] This application is a divisional application of the invention patent application filed on November 20, 2019, with application number 201980079664.2 and invention title "Cleaning Composition after Chemical Mechanical Polishing". Technical Field

[0002] This invention generally relates to compositions for removing cerium oxide particles and other chemical mechanical polishing slurry contaminants from microelectronic devices. Background Technology

[0003] Microelectronic device wafers are used to form integrated circuits. Microelectronic device wafers include a substrate, such as silicon, in which regions are patterned to deposit different materials having insulating, conductive, or semiconductive properties.

[0004] To achieve proper patterning, excess material used to form layers on the substrate must be removed. Furthermore, for the fabrication of functional and reliable circuits, it is important to prepare a flat or planar microelectronic wafer surface before subsequent processing. Therefore, certain surfaces of the microelectronic device wafer must be removed and / or polished.

[0005] Chemical mechanical polishing or planarization (“CMP”) is a method in which material is removed from the surface of a microelectronic device wafer and the surface is polished (e.g., planarized) by a combination of physical methods (e.g., abrasion) and chemical methods (e.g., oxidation or chelation). In its most basic form, CMP involves applying a polishing slurry containing active chemicals to a polishing pad that abrades the surface of the microelectronic device wafer during the removal, planarization, and polishing processes. For rapid and uniform removal, removal or polishing methods using purely physical or purely chemical operations are not as effective as using a synergistic combination of both. Furthermore, in the fabrication of integrated circuits, CMP slurries should also be able to preferentially remove films containing complex layers of metals and other materials, thereby producing highly flat surfaces for subsequent photolithography, patterning, etching, and thin-film processing.

[0006] In a front-end-of-the-line (FEOL) process for forming isolation regions in a silicon substrate using shallow trench isolation (STI), a pad oxide film and a pad nitride film are deposited on a semiconductor substrate and patterned to expose portions of the substrate corresponding to the isolation regions. The exposed regions of the substrate are then etched to form trenches. Subsequently, the substrate is subjected to a sacrificial oxidation process to remove damage caused by the substrate etching, followed by the formation of a wall oxide film on the surface of the trench. Next, an oxide film for the embedded trench (e.g., an oxide film formed by high-density plasma chemical vapor deposition, referred to as an HDP-oxide film) is deposited on the surface of the substrate in a manner similar to embedding the trench. The surface of the HDP-oxide film is then chemically mechanically polished until the pad nitride film is exposed. The resulting substrate is then cleaned and the pad nitride film, which served as an etch barrier during trench etching, is removed, thus completing the formation of the isolation regions.

[0007] For insulators, CMP pastes using cerium oxide particles typically achieve faster polishing speeds compared to silicon-based pastes. Furthermore, cerium oxide-based pastes are most commonly used due to their ability to achieve STI pattern planarization with minimal oxidation erosion. A disadvantage is that cerium oxide-based pastes are difficult to remove from STI structures because cerium oxide particles carry an opposite zeta potential to the silicon oxide and silicon nitride surfaces. If devices are fabricated with these residues remaining on the wafer, these residues will cause short circuits and increased resistance. Cerium oxide particles also pose a problem for FinFET structures after CMP processing using cerium oxide paste.

[0008] Currently, the most effective wet cleaning formulation for removing cerium oxide particles is dilute hydrofluoric acid (DHF). However, DHF is detrimental to etching silicon oxide and other low-k dielectric materials.

[0009] Therefore, there remains a need for a cerium oxide particle removal composition and method that can effectively remove cerium oxide particles from the surface of microelectronic devices without damaging underlying materials such as silicon nitride layers, low-k dielectric (e.g., silicon oxide) layers, and tungsten-containing layers. The cerium oxide particle removal composition should also effectively remove CMP slurry contaminants from the surface of microelectronic devices. Summary of the Invention

[0010] This invention generally relates to a removal composition and method, particularly suitable for cleaning cerium oxide particles and CMP contaminants from microelectronic devices, especially those with PETEOS, silicon nitride, and polycrystalline silicon substrates. In one aspect, an aqueous removal composition is described, comprising a nucleophile or reducing agent (effectively promoting cerium removal), certain surfactants and complexing agents, and optionally other components. In another aspect, a method is provided for removing cerium oxide particles and CMP contaminants from a microelectronic device, the method comprising contacting the microelectronic device with a removal composition for a time sufficient to at least partially clean the particles and composition from the microelectronic device, wherein the removal composition comprises a reducing agent or nucleophile, certain surfactants, complexing agents, and optionally other components. The surfactant is used to prevent redeposition of cerium oxide on the device surface and, in some cases, promotes removal due to a shift in reaction equilibrium towards complexation of cerium oxide species. Attached Figure Description

[0011] Figure 1 A scanning electron micrograph (SEM) of a polycrystalline silicon substrate after chemical mechanical polishing (CMP) but before treatment with the composition of the present invention.

[0012] Figure 2 SEM image of a polycrystalline silicon substrate after CMP treatment with the composition of Example 9.

[0013] Figure 3 SEM image of a polycrystalline silicon substrate after CMP treatment with the composition of Example 17.

[0014] Figure 4 SEM image of a polycrystalline silicon substrate after CMP treatment with the composition of Example 19.

[0015] Figure 5 SEM image of a PETEOS substrate after chemical mechanical polishing but before treatment with the composition of the present invention.

[0016] Figure 6 SEM image of a PETEOS substrate after CMP following treatment with the composition of Example 14.

[0017] Figure 7 SEM image of a PETEOS substrate after CMP following treatment with the composition of Example 25.

[0018] Figure 8 SEM image of a silicon nitride substrate after chemical mechanical polishing but before treatment with the composition of the present invention.

[0019] Figure 9SEM image of a silicon nitride substrate after CMP following treatment with the composition of Example 7.

[0020] Figure 10 SEM image of a silicon nitride substrate after CMP following treatment with the composition of Example 24. Detailed Implementation

[0021] This invention generally relates to compositions suitable for removing one or more of these materials from microelectronic devices containing cerium oxide particles and CMP contaminants. Advantageously, the compositions effectively remove cerium oxide particles and CMP contaminants, and additionally, the compositions are compatible with silicon nitride and low-k dielectric (e.g., silicon oxide) layers. At lower pH values, a reducing agent is used to break the cerium-oxygen bonds, and at higher pH values, a nucleophilic reagent is used to break the cerium-oxygen bonds.

[0022] For ease of reference, "microelectronic device" refers to semiconductor substrates, flat panel displays, phase-change memory devices, solar panels, and other products including solar substrates, photovoltaics, and microelectromechanical systems (MEMS) manufactured for microelectronic applications, integrated circuit applications, or computer chip applications. Solar substrates include, but are not limited to, silicon, amorphous silicon, polycrystalline silicon, monocrystalline silicon, CdTe, copper indium selenide, copper indium sulfide, and gallium arsenide on gallium. Solar substrates may be doped or undoped. It should be understood that the term "microelectronic device" is not intended to be limited in any way and includes any substrate that will ultimately become a microelectronic device or microelectronic assembly.

[0023] As used herein, “cerium oxide particles” corresponds to cerium-based polishing particles that can be used in chemical mechanical polishing slurries, including, for example, cerium oxide having the formulas Ce₂O₃ and CeO₂. It should be understood that “cerium oxide particles” may comprise cerium oxide, consist of cerium oxide, or consist substantially of cerium oxide.

[0024] As used herein, “contaminant” refers to chemicals present in CMP slurries, reaction byproducts of polishing slurries, post-CMP residues, chemicals present in wet etching compositions, reaction byproducts of wet etching compositions, and any other material that is a byproduct of CMP processes, wet etching, plasma etching, or plasma ashing processes.

[0025] As used herein, “post-CMP residue” refers to particles from the polishing slurry, such as chemicals present in the slurry, reaction byproducts of the polishing slurry, carbon-rich particles, polishing pad particles, brush-loaded particles, equipment materials used to build the particles, metals, organic residues, and any other materials that are byproducts of the CMP process. Furthermore, if tungsten is removed during the CMP process, the post-CMP residue may further contain tungsten-containing particles.

[0026] As defined herein, “low-k dielectric material” refers to any material used as a dielectric material in layered microelectronic devices, wherein the material has a dielectric constant of less than about 3.5. Generally, low-k dielectric materials include low-polarity materials such as silicon-containing organic polymers, silicon-containing hybrid organic / inorganic materials, organosilicon glasses (OSG), TEOS, fluorinated silicate glasses (FSG), silicon dioxide, and carbon-doped oxide (CDO) glasses. It should be understood that low-k dielectric materials can have different densities and different porosities.

[0027] As defined herein, "complexing agent" includes compounds that are understood by those skilled in the art to be complexing agents, chelating agents, and / or clamping agents. A complexing agent chemically combines with or physically clamps said metal atoms and / or metal ions to be removed using the composition described herein.

[0028] "Very largely free of" is defined in this document as less than 2 wt.%, less than 1 wt.%, less than 0.5 wt.%, or less than 0.1 wt.%. "Free of" is intended to correspond to less than 0.001 wt% to take into account environmental pollution.

[0029] As used in this article, “about” is intended to correspond to + / - 0.5% of the stated value.

[0030] As used herein, “oxidizing agent” refers to a compound that oxidizes exposed metal, causing corrosion or the formation of oxides on the metal. Oxidizing agents include (but are not limited to): hydrogen peroxide; other peroxide compounds, such as salts and acids containing peroxymonosulfate, perborate, perchlorate, periodate, persulfate, permanganate, and peracetic acid anions; and amine-N-oxides.

[0031] As used herein, "fluoride-containing compounds" refers to compounds containing fluoride ions (F ions) that are ionicly bonded to another atom. - ) salts or acid compounds.

[0032] As defined herein, the term "barrier material" refers to any material in the art used to seal metal wires (e.g., copper interconnects) to minimize the diffusion of the metal (e.g., copper) into the dielectric material. Preferred barrier layer materials include tantalum, titanium, ruthenium, hafnium, tungsten, and other refractory metals and their nitrides and silicides.

[0033] As used herein, “surfactant” corresponds to an amphiphilic species having both hydrophobic and hydrophilic groups, as will be readily understood by one of skill in the art, but does not include polymeric surfactants. As defined herein, “polymer” corresponds to a species having repeating monomer groups and may be natural or synthetic. It should be understood that a “polymer” may be a homopolymer having only one type of repeating monomer or a copolymer having more than one type of repeating monomer. Surfactants used in the compositions described herein include (but are not limited to) amphoteric salts, cationic surfactants, anionic surfactants, amphoteric surfactants, nonionic surfactants, and combinations thereof, including (but not limited to) decylphosphonic acid, dodecylphosphonic acid (DDPA), tetradecylphosphonic acid, hexadecylphosphonic acid, bis(2-ethylhexyl) phosphate, octadecylphosphonic acid, perfluoroheptanoic acid, perfluorodecanoic acid, trifluoromethanesulfonic acid, phosphonoacetic acid, dodecylbenzenesulfonic acid (DDBSA), other R1-benzenesulfonic acids or salts thereof (wherein R1 is a straight-chain or branched C8-C1 chain). 18Alkyl), dodecenyl succinic acid, di(octadecyl) hydrogen phosphate, octadecyl dihydrogen phosphate, dodecylamine, dodecenyl succinic acid monodiethanolamide, lauric acid, palmitic acid, oleic acid, juniperic acid, 12-hydroxystearic acid, octadecylphosphonic acid (ODPA), dodecyl phosphate. The nonionic surfactants covered include (but are not limited to) polyethylene lauryl ether, dodecenyl succinic acid monodiethanolamide, ethylenediaminetetra(ethoxylate-block-propoxylate)tetraol, polyethylene glycol, polypropylene glycol, polyethylene or polypropylene glycol ethers, block copolymers based on ethylene oxide and propylene oxide, polyoxypropylene sucrose ether, tert-octylphenoxypolyethoxyethanol, 10-ethoxy-9,9-dimethyldecyl-1-amine, branched polyoxyethylene (9) nonylphenyl ether, branched polyoxyethylene (40) nonylphenyl ether, dinonyl... Ethylphenyl oxide, nonylphenol alkoxylate, polyethylene oxide sorbitol hexaoleate, polyethylene oxide sorbitol tetraoleate, polyethylene glycol dehydrated sorbitol monooleate, dehydrated sorbitol monooleate, alcohol alkoxylate, alkyl-polyglucoside, perfluorobutyrate ethyl ester, 1,1,3,3,5,5-hexamethyl-1,5-bis[2-(5-norbornene-2-yl)ethyl]trisiloxane, monooctadecylsilane derivatives, siloxane-modified polysilazane, siloxane-polyether copolymers, and ethoxylated fluorinated surfactants. The cationic surfactants covered include (but are not limited to) cetyltrimethylammonium bromide (CTAB), heptadecanofluorooctane sulfonic acid, tetraethylammonium, stearyltrimethylammonium chloride, 4-(4-diethylaminophenylaza)-1-(4-nitrobenzyl)pyridinium bromide, hexadecylpyridinium chloride monohydrate, benzalkonium chloride, benzyltrimethylammonium chloride, benzyldimethyldodecylammonium chloride, benzyldimethylhexadecylammonium chloride, hexadecyltrimethylammonium bromide, dimethyldi(octadecyl)ammonium chloride, and decadecylamine chloride. Dialkyltrimethylammonium, hexadecyltrimethylammonium p-toluenesulfonate, di(dodecyl)dimethylammonium bromide, di(hydrogenated tallow)dimethylammonium chloride, tetra(heptyl)ammonium bromide, tetra(decyl)ammonium bromide, and olfenammonium bromide, guanidine hydrochloride (C(NH2)3Cl), or trifluoromethanesulfonates (e.g., tetrabutyltrifluoromethanesulfonate), dimethyl di(octadecyl)ammonium chloride, dimethyl di(hexadecyl)ammonium bromide, di(hydrogenated tallow)dimethylammonium chloride, and polyoxyethylene (16) tallow ethylammonium ethyl sulfate. The anionic surfactants covered include (but are not limited to) sodium poly(acrylate), ammonium polyacrylate, sodium polyoxyethylene lauryl ether, sodium dihexyl sulfosuccinate, sodium dodecyl sulfate, dioctyl sulfosuccinate, 2-sulfosuccinate, 2,4,7,9-tetramethyl-5-decyn-4,7-diol and its ethoxy derivatives, 2,3-dimercapto-1-propanesulfonate, sodium dicyclohexyl sulfosuccinate, sodium 7-ethyl-2-methyl-4-undecyl sulfate, fluorinated phosphate surfactants, fluorinated surfactants and polyacrylates.Amphoteric surfactants include (but are not limited to) acetylenic diols or modified acetylenic diols, ethylene oxide alkylamines, N,N-dimethyldodecylamine N-oxides, sodium cocoamine propionate, 3-(N,N-dimethylmyristylammonium)propane sulfonate and (3-(4-heptyl)phenyl-3-hydroxypropyl)dimethylammonium propane sulfonate.

[0034] As used herein, the “suitability” for removing cerium oxide particles and CMP contaminants from a microelectronic device corresponds to at least partial removal of the particles / contaminants from the microelectronic device. Cleaning effectiveness is assessed by the reduction of objects on the microelectronic device. For example, atomic force microscopy can be used for pre-cleaning and post-cleaning analyses. Particles on the sample can be recorded as pixel ranges. Histograms (e.g., Sigma Scan Pro) can be applied to filter pixels at a specific intensity (e.g., 231-235) and count the number of particles. Particle reduction can be calculated using the following:

[0035]

[0036] It is important to note that the methods for measuring cleaning efficacy are provided as examples only and are not intended to limit us to these examples. Alternatively, cleaning efficacy can be considered as the percentage of the total surface covered by particulate matter. For example, an AFM can be programmed to perform a z-plane scan to identify areas of surface morphology of interest above a certain height threshold, and the total surface area covered by said areas of interest can then be calculated. Those skilled in the art will readily understand that the smaller the area covered by said areas of interest after cleaning, the more effective the removal composition. In some embodiments, using the compositions described herein, at least 75% of particles / contaminants are removed from microelectronic devices, at least 90%, at least 95%, or at least 99% of particles / contaminants are removed.

[0037] As described more fully below, the compositions described herein can be manifested in a wide variety of specific formulations.

[0038] In all the compositions described, wherein the reference weight percentage range (including the lower limit of zero) refers to a particular component of the composition, it should be understood that the component may be present or absent in various specific embodiments of the composition, and in instances where the component is present, it may be present at a concentration as low as 0.00001 weight percentage based on the total weight of the composition employing the component.

[0039] In a first aspect, the present invention provides a composition comprising

[0040] (i) at least one surfactant;

[0041] (ii) at least one pH adjuster;

[0042] (iii) at least one complexing agent;

[0043] (iv) at least one organic additive; and

[0044] (v) Alternatively, at least one nucleophilic compound or reducing agent is present when the composition has a pH of about 11 to 13.7, and the reducing agent is present when the composition has a pH of less than 6.

[0045] In another embodiment, the present invention provides a composition comprising

[0046] (i) at least one surfactant;

[0047] (ii) at least one pH adjuster;

[0048] (iii) at least one complexing agent;

[0049] (iv) at least one organic additive; and

[0050] (v) at least one nucleophilic compound, wherein the composition has a pH of about 11 to 13.7.

[0051] In another embodiment, the present invention provides a composition comprising

[0052] (i) at least one surfactant;

[0053] (ii) at least one pH adjuster;

[0054] (iii) at least one complexing agent;

[0055] (iv) at least one organic additive; and alternatively

[0056] (v) at least one reducing agent, wherein the composition has a pH of about 4 to 6.

[0057] As used herein, the term "nucleophile" is understood to be a compound that acts as a nucleophile in a chemical reaction. In other words, a nucleophile is a chemical species that can donate electron pairs to an electrophile to form a reaction-related chemical bond. In the present invention, at a relatively high pH range of about 11 to 13.7, a nucleophile is utilized and used to break the cerium-oxygen bond; the accompanying complexation of cerium oxide particles is used to facilitate their removal from the surface of the microelectronic device.

[0058] In one embodiment, the nucleophile is an amine. Examples include monoethanolamine (MEA), morpholine, isopropylamine, diisopropanolamine, diethylene glycolamine, triethylamine, N-methylmorpholine, methylethanolamine, N-aminopropylmorpholine, and 3-aminopropanol.

[0059] Other nucleophilic compounds include those with the general formula NR 1 R 2 R 3 Species, of which R 1 R 2 and R 3 C1-C6 alkyl ethers, which may be the same as or different from each other and selected from hydrogen, straight-chain or branched C1-C6 alkyl (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl), straight-chain or branched C1-C6 hydroxyalkyl (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, and hydroxyhexyl), and straight-chain or branched C1-C6 hydroxyalkyl, as defined above. In some embodiments, R 1 R 2 and R 3 At least one of them is a straight-chain or branched C1-C6 hydroxyalkyl group. Examples include (but are not limited to) alkanolamines, such as aminoethylethanolamine, N-methylaminoethanol, aminoethoxyethanol, dimethylaminoethoxyethanol, diethanolamine, N-methyldiethanolamine, monoethanolamine (MEA), triethanolamine (TEA), 1-amino-2-propanol, 2-amino-1-butanol, isobutanolamine, triethylenediamine, triethylenetetramine, diethylenetriamine, methylmorpholine, ethylmorpholine, morpholine, 3-aminopropanol, dimethylaminoprop-3-ol, diethylene glycolamine, triethylamine, benzylmethylamine, aminomethylpropanol, dimethylaminopropanolamine, other C1-C8 alkanolamines and combinations thereof. When the amine includes an alkyl ether component, the amine may be considered an alkoxyamine, such as 1-methoxy-2-aminoethane.

[0060] In the present invention, at a lower pH range below 6, and this may be in the range of 1 to 3 or 1 to 6, a reducing agent is used to break the cerium-oxygen bond; the accompanying complexation of cerium oxide particles is used to facilitate their removal from the surface of the microelectronic device. As used herein, the reducing agents covered include compounds selected from: hypophosphorous acid (H3PO2), ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives, DEHA (diethylhydroxylamine), sulfurous acid, sodium thiosulfate, potassium thiosulfate, ammonium thiosulfate, potassium dithionite, and combinations thereof.

[0061] In one embodiment, the composition is substantially free of fluorine compounds and oxidants.

[0062] In one embodiment, the composition further comprises a solvent comprising water. Organic additives may also be present. Examples of organic additives include glycols and glycol ethers, including but not limited to methanol, ethanol, isopropanol, butanol, and higher alcohols (e.g., C2-C4 glycols and C2-C4 triols), tetrahydrofurfuryl alcohol (THFA), and halogenated alcohols (e.g., 3-chloro-1,2-propanediol, 3-chloro-1-propanethiol, 1-chloro-2-propanol, 2-chloro-1-propanol, 3-chloro-1-propanol, 3-bromo-1,2-propanediol, 1-bromo-2-propanol, 3-bromo-1-propanol, 3-iodo-1-propanol). 4-Chloro-1-butanol, 2-chloroethanol), dichloromethane, chloroform, acetic acid, propionic acid, trifluoroacetic acid, tetrahydrofuran, N-methylpyrrolidone (NMP), cyclohexylpyrrolidone, N-octylpyrrolidone, N-phenylpyrrolidone, methyl diethanolamine, methyl formate, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetramethylene sulfone (sulfolane), diethyl ether, phenoxy-2-propanol (PPh), phenylacetone, ethyl lactate, ethyl acetate, ethyl benzoate Ester, Acetonitrile, Acetone, Ethylene Glycol, Propylene Glycol (PG), 1,3-Propane Glycol, Dioxane, Butyryl Lactone, Butylene Carbonate, Ethylene Carbonate, Propylene Carbonate, Dipropylene Glycol, Diethylene Glycol Monomethyl Ether, Triethylene Glycol Monomethyl Ether, Diethylene Glycol Monoethyl Ether, Triethylene Glycol Monoethyl Ether, Ethylene Glycol Monopropyl Ether, Ethylene Glycol Monobutyl Ether, Diethylene Glycol Monobutyl Ether (i.e., Butyl Carbitol), Triethylene Glycol Monobutyl Ether, Ethylene Glycol Monohexyl Ether, Diethylene Glycol Monohexyl Ether, Ethylene Glycol phenyl Ether, Propylene Glycol Methyl Ether, Dipropylene Glycol Methyl Ether Ethers (DPGME), tripropylene glycol methyl ether (TPGME), dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, dipropylene glycol methyl ether acetate, tetraethylene glycol dimethyl ether (TEGDE), diesters, glycerol carbonates, N-formylmorpholine, triethyl phosphate, polystyrene sulfonic acid (PSSA), and combinations thereof.

[0063] In various embodiments, the removal composition may substantially be free of at least one of the following: oxidizing agents; fluoride sources; tetramethylammonium hydroxide; chemical mechanical polishing abrasives (e.g., silica, alumina, etc.); and corrosion inhibitors selected from the group consisting of: cyanuric acid, barbituric acid and its derivatives, glucuronic acid, squaric acid, α-keto acid, adenosine and its derivatives, ribosylpurine and its derivatives, purine compounds and their derivatives, degradation products of adenosine and its derivatives, triaminopyrimidine and other substituted pyrimidines, purine-glycoside complexes, phenobarbital, glycine, nicotinamide and its derivatives, flavonoids (e.g., flavonols and anthocyanins and their derivatives), quercetin and its derivatives, and combinations thereof, subsequently removing residual substances from the microelectronic device. Additionally, the removal composition should not be cured to form a polymeric solid.

[0064] The complexing agent may be a polyfunctional amine, including (but not limited to) amines. 4-(2-hydroxyethyl)morpholine (HEM), 1,2-cyclohexanediamine-N,N,N',N'-tetraacetic acid (CDTA), hydroxyethyl ethylenediamine triacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), m-xylenediamine (MXDA), iminodiacetic acid (IDA), trimethylamine, isopropanolamine, diisopropanolamine, piperazine, hydroxyethyl piperazine, dihydroxyethyl piperazine, reduced glucosamine, N-methyl reduced glucosamine, 2-(hydroxyethyl)iminodiacetic acid (HIDA), nitrotriacetic acid, thiourea, 1,1,3,3-tetramethylurea, urea, urea derivatives, uric acid, alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, taurine, betaine, and combinations thereof.

[0065] Alternatively, or in addition to the aforementioned complexing agents, other complexing agents may include phosphonates (e.g., 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), 1,5,9-triazacyclododecane-N,N',N''-tris(methylenephosphonic acid) (DOTRP), 1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetra(methylenephosphonic acid) (DOTP), azoxytris(methylene)triphosphonic acid, diethylenetriaminepenta(methylenephosphonic acid) (DETAP), aminotris(methylenephosphonic acid), bis(hexamethylene)triaminepentamethylenephosphonic acid, 1,4,7-triazacyclononane-N,N',N''-tris(methylenephosphonic acid) (NOTP), hydroxyethyl diphosphate, azirmonotris(methylene)phosphonic acid, 2-phosphono-butane-1,2,3,4-tetracarboxylic acid, carboxyethylphosphonic acid, aminoethylphosphonic acid, glyphosate, ethylenediaminetetra(methylenephosphonic acid)phenylphosphonic acid, its salts and derivatives) and / or carboxylic acids (e.g., oxalic acid, succinic acid, maleic acid, malic acid, malonic acid, adipic acid, phthalic acid, citric acid, sodium citrate, potassium citrate, ammonium citrate, tricarboxylic acid, trimethylolpropionic acid, pyridinecarboxylic acid, dipyridinecarboxylic acid, salicylic acid sulfosalicylic acid, sulfophthalic acid, sulfosuccinic acid, anhydrous betaine, gluconic acid, tartaric acid, glucuronic acid, 2-carboxypyridine) and / or sulfonic acids, such as trion (disodium salt of 4,5-dihydroxy-1,3-benzenedisulfonic acid). In some embodiments, the complexing agent comprises a nitrogen group (tris-methylenephosphonic acid) and iminodiacetic acid. In some embodiments, at least one complexing agent comprises a species selected from monoethanolamine, triethanolamine, sulfuric acid, citric acid, and combinations thereof. In one embodiment, the amount of one or more complexing agents removed from the composition is in the range of about 0.01 wt% to about 10 wt% based on the total weight of the removed composition.

[0066] Suitable pH adjusters include acids and / or bases. Bases include (but are not limited to) potassium hydroxide, ammonium hydroxide (i.e., ammonia), and substances with the formula NR. 4 R 5 R 6 R 7 OH tetraalkylammonium hydroxide compounds, wherein R 4 R 5 R 6 and R 7 They may be the same as or different from each other and are selected from the group consisting of: hydrogen, straight-chain or branched C1-C6 alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl), C1-C6 hydroxyalkyl groups (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, and hydroxyhexyl), and substituted or unsubstituted C6-C groups. 10 Aryl (e.g., benzyl). Commercially available tetraalkylammonium hydroxides include tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), tributylmethylammonium hydroxide (TBMAH), benzyltrimethylammonium hydroxide (BTMAH), choline hydroxide, ethyltrimethylammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide, diethyldimethylammonium hydroxide, and combinations thereof. Alternatively or additionally, pH adjusters may be those having the formula (PR... 8 R 9 R 10 R 11 )OH quaternary base, of which R 8 R 9 R 10 and R 11 They may be the same as or different from each other and are selected from the group consisting of: hydrogen, straight-chain C1-C6 alkyl (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl), branched-chain C1-C6 alkyl, C1-C6 hydroxyalkyl (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, and hydroxyhexyl), and substituted C6-C 10 Aryl, unsubstituted C6-C 10Aryl groups (e.g., benzyl) and any combination thereof, such as tetrabutylphosphonium hydroxide (TBPH), tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrapropylphosphonium hydroxide, benzyltriphenylphosphonium hydroxide, methyltriphenylphosphonium hydroxide, ethyltriphenylphosphonium hydroxide, and N-propyltriphenylphosphonium hydroxide. Acids include (but are not limited to) nitric acid, sulfuric acid, phosphoric acid, hydrochloric acid, hydrobromic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, acetic acid, lactic acid, glycolic acid, and any combination thereof. In one embodiment, the pH adjuster is selected from at least one of KOH and CsOH. In another embodiment, the pH adjuster comprises choline hydroxide. In another embodiment, the pH adjuster comprises ammonium hydroxide. In another embodiment, the pH adjuster comprises KOH and at least one additional hydroxide listed herein. In yet another embodiment, the pH adjuster comprises KOH and at least one of choline hydroxide and ammonium hydroxide. For any of these enumerated embodiments, the pH adjuster may further comprise at least one acid, such as nitric acid, sulfuric acid, phosphoric acid, or a combination thereof.

[0067] In one embodiment of the invention, the pH value will be adjusted to be higher than about 9, and in another embodiment, higher than 13 or about 13.1. In one embodiment of the invention, the pH value will be adjusted to be lower than 6, or from about 4 to about 6, and in another embodiment about 6.

[0068] Polymers (if present) include (but are not limited to) homopolymers of methacrylic acid and copolymers with, for example, acryloylaminomethylpropanesulfonic acid and maleic acid; maleic acid / vinyl ether copolymers; poly(vinylpyrrolidone) / vinyl acetate; homopolymers such as phosphonated polyethylene glycol oligomers, poly(acrylic acid) (PAA), poly(acrylamide), poly(vinyl acetate), poly(ethylene glycol) (PEG), and polypropylene glycol. (PPG), poly(styrene sulfonic acid), poly(vinyl sulfonic acid), poly(vinyl phosphonic acid), poly(vinyl phosphate), poly(ethylene imine), poly(propylene imine), polyallylamine, polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), PPG-PEG-PPG block copolymer, PEG-PPG-PEG block copolymer, poly(vinyl alcohol), poly(hydroxyethyl) acrylate, poly(hydroxyethyl) methacrylate, hydroxyethyl cellulose, methyl hydroxyethyl cellulose, hydroxypropyl cellulose, methyl hydroxypropyl cellulose, succinate, potassium alginate, pectin, carboxymethyl cellulose, glucosamine, poly(diallyl dimethyl ammonium) chloride, polyAMPS, PVA AMPS copolymers (where "AMPS" represents poly(2-acryloylamino-2-methyl-1-propanesulfonic acid), PEGylated (i.e., PEGylated) methacrylate / acrylate copolymers, polyMADQuat and its copolymers, dimethylamino methacrylate polymers and their copolymers, trimethylammonium methacrylate polymers and their copolymers, and combinations thereof. These copolymers may be random copolymers or block copolymers. If present, the amount of one or more polymers in the composition ranges from about 0.0001% by weight to about 5% by weight based on the total weight of the composition.

[0069] The composition can be readily formulated by simply adding the appropriate ingredients and mixing until homogeneous. Furthermore, the composition can be readily formulated as a single-package formulation or as a multi-part formulation to be mixed at or before use; for example, individual portions of a multi-part formulation may be mixed at the tool or in a reservoir upstream of the tool. The concentration of the appropriate ingredients can vary widely across specific multiples of the composition, i.e., becoming more dilute or more concentrated, and it should be understood that the compositions described herein may differently and alternatively comprise, consist of, or substantially consist of any combination of ingredients consistent with the disclosure herein.

[0070] Regarding the composition ratio, in some embodiments, the surfactant is present in an amount of about 0.01 to 0.5% by weight, and the sum of (i), (ii), (iii), (iv), and (v) equals 100% by weight. In some embodiments, the complexing agent is present in an amount of about 1 to 5% by weight, and the sum of (i), (ii), (iii), (iv), and (v) equals 100% by weight. In some embodiments, the organic additive is present in an amount of about 0.5% to 2.5% by weight. In some embodiments, component (v) is present in an amount of about 1 to 5% by weight, and the sum of (i), (ii), (iii), (iv), and (v) equals 100% by weight.

[0071] Based on the pH values ​​disclosed herein and the knowledge of those skilled in the art, the amount of pH adjuster depends on the final pH sought when preparing the removal composition for use.

[0072] The range of weight percentages of the components will cover all embodiments in which the composition may be concentrated or diluted. For this purpose, in one embodiment, a concentrated removal composition is provided, which can be diluted for use as a cleaning solution. The concentrated composition or “concentrate” advantageously allows users (e.g., CMP process engineers) to dilute the concentrate to the desired strength and pH during use. Dilution of the concentrated aqueous removal composition may range from about 1:1 to about 2500:1, about 5:1 to about 200:1, or about 20:1 to about 120:1, wherein the aqueous removal composition is diluted with a solvent (e.g., deionized water) at or just before the tool. Those skilled in the art will understand that the range of weight percentages of the components disclosed herein should remain unchanged after dilution.

[0073] The applications of the compositions described herein include, but are not limited to, post-etching residue removal, post-ashing residue removal surface treatments, post-electroplating cleaning, and post-CMP residue removal. Additionally, the aqueous cleaning compositions described herein are intended for use in cleaning and protecting other metal (e.g., copper-containing and tungsten-containing) products, including (but not limited to) decorative metals using metals or metal alloys, wire bonding, printed circuit boards, and other electronic packages.

[0074] In yet another embodiment, the removal composition described herein further comprises cerium oxide particles and / or CMP contaminants. The cerium oxide particles and contaminants become components of the removal composition after cleaning has commenced and will dissolve and / or suspend in the composition.

[0075] The removal composition can be easily formulated by simply adding the appropriate ingredients and mixing until homogeneous. Furthermore, the composition can be readily formulated as a single-package formulation or as a multi-part formulation to be mixed at or before use; for example, individual portions of a multi-part formulation can be mixed at the tool or in a reservoir upstream of the tool. The concentration of the appropriate ingredients can vary widely across specific multiples of the composition, i.e., becoming more dilute or more concentrated, and it should be understood that the compositions described herein may differently and alternatively comprise, consist of, or substantially consist of any combination of ingredients consistent with the disclosure herein.

[0076] Therefore, another aspect relates to a kit comprising, in one or more containers, one or more components adapted to form the compositions described herein. The kit may comprise, in one or more containers, (i) at least one surfactant; (ii) at least one pH adjuster; (iii) at least one complexing agent; (iv) at least one organic additive; and alternatively (v) at least one nucleophilic compound or reducing agent for use in combination with additional solvents (e.g., water). The containers of the kit must be suitable for storing and shipping the compositions and may be, for example, NOWPak® containers (Entegris, Inc., Billerica, Mass., USA).

[0077] In one embodiment, one or more containers containing components of an aqueous removal composition include means for fluidly communicating the components in the one or more containers for blending and dispensing. For example, referring to the NOWPak® container, gas pressure can be applied to the outside of the liner in the one or more containers to release at least a portion of the contents of the liner and thus enable fluid communication for blending and dispensing. Alternatively, gas pressure can be applied to the top space of a conventional pressurized container or pump that can be used to enable fluid communication. Additionally, in some embodiments, the system includes a dispensing port for dispensing the blended removal composition to a treatment tool.

[0078] When applied in microelectronics manufacturing operations, the removal compositions described herein are effective for cleaning cerium oxide particles and / or CMP contaminants (e.g., post-CMP residues and contaminants) from the surfaces of microelectronic devices. The removal compositions do not impair low-k dielectric materials (e.g., silicon oxide), silicon nitride layers, or tungsten-containing layers on the device surface. In one embodiment, the aqueous removal composition removes at least 85%, at least 90%, at least 95%, or at least 99% of the cerium oxide particles present on the device prior to particle removal.

[0079] Therefore, in another aspect, the present invention provides a method for removing cerium oxide particles and chemical mechanical polishing contaminants from a microelectronic device, the method comprising:

[0080] (i) bringing a microelectronic device into contact with the composition of the present invention; and

[0081] (ii) At least partially removing the particles and contaminants from the microelectronic device, wherein the microelectronic device comprises a substrate selected from polysilicon, PETEOS and silicon nitride.

[0082] In post-CMP particle and contaminant removal applications, the aqueous removal compositions described herein can be used with a variety of conventional cleaning tools, such as mega-sonic ultrasonic and brush scrubbing, including (but not limited to) the Verteq single-crystal mega-sonic ultrasonic Goldfinger, the OnTrak system DDS (dual-sided scrubber), SEZ or other single-crystal spray rinsing, Applied Materials Mirra-Mesa™ / Reflexion™ / Reflexion LK™, and Megasonic batch wet cleaning station systems.

[0083] When using the compositions described herein to remove cerium oxide particles and CMP contaminants from a microelectronic device, the aqueous removal composition is typically contacted with the device for a period of about 5 seconds to about 10 minutes, or about 1 second to 20 minutes, or about 15 seconds to about 5 minutes at a temperature typically ranging from about 20°C to about 90°C or from about 20°C to about 50°C. These contact times and temperatures are illustrative, and any other suitable time and temperature conditions may be used to effectively remove at least partially cerium oxide particles and CMP contaminants from the device within the broad practice of the method. "At least partially cleaned" and "substantially removed" in some embodiments correspond to the removal of at least 85%, at least 90%, at least 95%, or at least 99% of the cerium oxide particles present on the device prior to particle removal.

[0084] After the desired particle removal operation is achieved, the aqueous removal composition can be readily removed from the apparatus to which it was previously applied, as is desirable and effective in the intended end-use application of the composition described herein. In one embodiment, the rinsing solution comprises deionized water. Subsequently, the apparatus can be dried using nitrogen or a rotary drying cycle.

[0085] On the other hand, it relates to improved microelectronic devices made according to the methods described herein and to products containing such microelectronic devices.

[0086] On the other hand, it relates to a recirculating aqueous removal composition, wherein, as readily determined by those skilled in the art, the removal composition can be recycled until the particle and / or contaminant load reaches the maximum amount that the aqueous removal composition can accommodate.

[0087] Another aspect relates to a method of manufacturing an article comprising a microelectronic device, the method comprising contacting the microelectronic device with an aqueous removal composition for a duration sufficient to remove the particles and contaminants from the microelectronic device having cerium oxide particles and CMP contaminants thereon, and incorporating the microelectronic device into the article using the removal composition described herein.

[0088] In another aspect, a method for removing cerium oxide particles and CMP contaminants from a microelectronic device is described. The method includes polishing the microelectronic device with a CMP slurry containing cerium oxide particles; contacting the microelectronic device with an aqueous removal composition comprising at least one pH adjuster, at least one reducing agent, at least one organic additive, water, optionally at least one complexing agent, optionally at least one polymer, and optionally at least one oxygen scavenger for a duration sufficient to remove the cerium oxide particles and CMP contaminants from the microelectronic device to form a post-CMP particle-containing composition; and continuing to contact the microelectronic device with the post-CMP particle-containing composition for a duration sufficient to achieve substantial cleaning of the microelectronic device. Any of the components described above can be used in the method of removing cerium oxide particles and CMP contaminants of the present invention.

[0089] The invention can be further illustrated by the following examples of its preferred embodiments, but unless otherwise specifically indicated, it should be understood that these examples are included for illustrative purposes only and are not intended to limit the scope of the invention.

[0090] Experimental Section

[0091] In Examples 1 to 28 below, in addition to the nucleophilic compound (morpholine) used as a cerium-oxygen bond disruptor in these examples, choline hydroxide was used to adjust the pH of each composition to about 13.1.

[0092] Table 1

[0093]

[0094]

[0095] In the following examples, substrate samples were placed in a cerium oxide slurry for 5 minutes, followed by immersion in deionized water (DIW) for 30 seconds to remove any adsorbed or loosely bound species. The DIW-treated samples were then placed in a cleaning solution for 1 minute, followed by rinsing with DIW for 30 seconds. The substrates were air-dried, and the remaining areas covered by cerium oxide were calculated using scanning electron microscopy (SEM). In these examples, choline hydroxide was used to adjust the pH of the aqueous composition to approximately 6.1.

[0096] Table 2

[0097]

[0098]

[0099]

[0100] In the following example, defects were determined by polishing a TEOS wafer with a commercially available cerium oxide slurry on an AMAT Mirra tool using a polishing blanket, followed by brush cleaning with an Entegris Planarcore® brush. Total defects at the 110 nm threshold were then analyzed on a KLA-Tencore SP1.

[0101] Table 3

[0102]

[0103] Therefore, based on the described illustrative embodiments of the invention, those skilled in the art will readily understand that other embodiments can be made and used within the scope of the appended claims. Many advantages of the invention as covered herein have been set forth in the foregoing description. However, it should be understood that the invention is illustrative in many respects only. Changes may be made, particularly in the shape, size, and arrangement of components, without departing from the scope of the invention. Of course, the scope of the invention is defined by the language of the appended claims.

Claims

1. A method for removing cerium oxide particles and chemical mechanical polishing contaminants from a microelectronic device, the method comprising: (i) bringing the microelectronic device into contact with the composition, the composition comprising: The composition comprises at least one surfactant; at least one pH adjuster; at least one complexing agent; at least one organic additive, wherein the at least one organic additive comprises at least one of triethylene glycol monobutyl ether and propylene glycol methyl ether; and at least one nucleophilic compound, wherein the at least one nucleophilic compound is morpholine; wherein the composition has a pH greater than 13; and wherein the composition is substantially free of oxidants.

2. The method according to claim 1, wherein the pH adjuster is choline hydroxide.

3. The method according to any one of claims 1 to 2, wherein the complexing agent is 1-hydroxyethylidene-1,1-diphosphonic acid.

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