Compositions and methods for removing cerium oxide particles from surfaces

Abstract

The present application relates to compositions and methods for removing cerium oxide particles from a surface. The present invention relates to a removal composition and process for cleaning chemical mechanical polishing (CMP) post-contaminants and cerium oxide particles from a microelectronic device having the particles and contaminants thereon. The composition enables highly effective removal of the cerium oxide particles and CMP contaminant material from the surface of the microelectronic device without damaging low-k dielectric materials, silicon nitride or tungsten-containing materials.

Description

[0001] Information about divisional applications

[0002] This application is a divisional application of an invention patent application with an application date of January 17, 2018, an application number of 201880007539.6, and an invention name of “Compositions and methods for removing cerium oxide particles from a surface”.

[0003] Related Applications

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 447,729, filed on January 18, 2017, the entire disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0005] The present invention generally relates to compositions for removing cerium oxide particles and other chemical mechanical polishing slurry contaminants from microelectronic devices having such particles and contaminants thereon. Background Art

[0006] Microelectronic device wafers are used to form integrated circuits.Microelectronic device wafers include a substrate, such as silicon, into which a plurality of regions are patterned for the deposition of different materials having insulating, conducting or semiconducting properties.

[0007] To achieve correct patterning, excess material used to form the layers on the substrate must be removed. In addition, to produce functional and reliable circuits, it is critical to prepare a smooth or flat microelectronic wafer surface prior to subsequent processing. Therefore, it is necessary to remove and / or polish certain surfaces of the microelectronic device wafer.

[0008] Chemical mechanical polishing or planarization ("CMP") is a process that removes material from the surface of a microelectronic device wafer and polishes (e.g., planarizes) the surface by coupling a physical process (e.g., abrasion) with a chemical process (e.g., oxidation or chelation). In its most basic form, CMP involves applying an abrasive slurry with active chemistry to a polishing pad that polishes the surface of the microelectronic device wafer during the removal, planarization, and polishing processes. Removal or polishing processes that utilize purely physical or purely chemical action are not as effective as a synergistic combination of the two in achieving rapid, uniform removal. Additionally, in the manufacture of integrated circuits, CMP slurries should also be able to preferentially remove films that include composite layers of metals and other materials so that a highly planar surface can be produced for subsequent photolithography or patterning, etching, and thin film processing.

[0009] In a front-end process (FEOL) method of forming an isolation region in a silicon substrate using a shallow trench isolation (STI) process, a pad oxide film and a pad nitride film are deposited on a semiconductor substrate and patterned to expose a portion of the substrate corresponding to the isolation region. Then, the exposed area of ​​the substrate is etched to form a trench. Thereafter, the substrate is subjected to a sacrificial oxidation process to remove damage caused by substrate etching, and a wall oxide film is subsequently formed on the surface of the trench. Then, a trench-buried oxide film (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 such a manner that it is buried in the trench. Then, the surface of the HDP-oxide film is subjected to chemical mechanical polishing until the pad nitride film is exposed. The resulting substrate is then cleaned and the pad nitride film used as an etching barrier during trench etching is removed, thereby completing the formation of the isolation region.

[0010] CMP slurries using cerium oxide particles achieve faster polishing rates for insulators relative to slurries containing silicon dioxide. In addition, cerium oxide-based slurries are most commonly used due to their ability to achieve STI pattern planarization and minimal oxide corrosion. Disadvantageously, cerium oxide-based slurries are difficult to remove from STI structures due to the zeta potential of the cerium oxide particles, which is electrically opposite to silicon oxide and silicon nitride surfaces. If a device is fabricated and these residues remain on the wafer, the residues will cause short circuits and increased resistance. Cerium oxide particles also have the problem of having a FinFET structure after CMP processing using cerium oxide slurries.

[0011] The most effective wet cleaning formulation currently used to remove cerium oxide particles is dilute hydrofluoric acid (DHF). However, DHF adversely etches silicon oxide and other low-k dielectric materials.

[0012] Therefore, there is still a need in the industry for a cerium oxide particle removal composition and process that can effectively remove cerium oxide particles from the surface of a microelectronic device without damaging underlying materials such as silicon nitride, low-k dielectrics (such as silicon oxide), and tungsten-containing layers. The cerium oxide particle removal composition should also effectively remove CMP slurry contaminants from the surface of a microelectronic device. Summary of the invention

[0013] The present invention generally relates to removal compositions and processes, and in particular, can be used to clean cerium oxide particles and CMP contaminants from microelectronic devices having the particles thereon.

[0014] In one aspect, an aqueous removal composition is described that includes at least one pH adjuster, at least one reducing agent, at least one organic additive, water, optionally at least one complexing agent, and optionally at least one oxygen scavenger.

[0015] In another aspect, a method of removing cerium oxide particles and CMP contaminants from a microelectronic device having the particles and contaminants thereon is described, the method comprising contacting the microelectronic device with a removal composition for a sufficient time to at least partially clean the particles and contaminants from the microelectronic device, wherein the removal composition comprises at least one pH adjuster, at least one reducing agent, at least one organic additive, water, optionally at least one complexing agent, and optionally at least one oxygen scavenger.

[0016] In another aspect, an article is described that includes an aqueous removal composition, a microelectronic device wafer, and a material selected from the group consisting of cerium oxide particles, CMP contaminants, and combinations thereof, wherein the cleaning composition includes at least one pH adjuster, at least one reducing agent, at least one organic additive, water, optionally at least one complexing agent, and optionally at least one oxygen scavenger.

[0017] Other aspects, features and advantages will be more fully apparent from the ensuing disclosure and appended claims. DETAILED DESCRIPTION

[0018] The present invention generally relates to compositions that can be used to remove cerium oxide particles and CMP contaminants from microelectronic devices having the materials thereon. Advantageously, cerium oxide particles and CMP contaminants are effectively removed using the compositions, and further the compositions are compatible with silicon nitride and low-k dielectric (eg, silicon oxide) layers.

[0019] For ease of reference, "microelectronic devices" correspond 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 microelectronic, 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-on-gallium arsenide. Solar substrates may be doped or undoped. It should be understood that the term "microelectronic device" is not intended to be limiting in any way and includes any substrate that will eventually become a microelectronic device or microelectronic assembly.

[0020] As used herein, "cerium oxide particles" correspond to cerium-based abrasive particles that can be used in chemical mechanical polishing slurries, including, for example, cerium oxides having the formula Ce2O3 and CeO2. It should be understood that "cerium oxide particles" may include, consist of, or consist essentially of cerium oxide.

[0021] As used herein, "contaminants" correspond 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 materials that are byproducts of a CMP process, wet etching, plasma etching, or plasma ashing processes.

[0022] As used herein, "post-CMP residue" corresponds 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-load-relief particles, equipment materials from which particles are constructed, metals, organic residues, and any other materials that are byproducts of the CMP process. Additionally, if tungsten is removed during the CMP process, the post-CMP residue may additionally include tungsten-containing particles.

[0023] As defined herein, "low-k dielectric material" corresponds to any material used as a dielectric material in a layered microelectronic device, wherein the material has a dielectric constant of less than about 3.5. Preferably, the low-k dielectric material comprises a low polarity material such as silicon-containing organic polymers, silicon-containing hybrid organic / inorganic materials, organosilicate glass (OSG), TEOS, fluorinated silicate glass (FSG), silicon dioxide, and carbon-doped oxide (CDO) glass. It should be understood that the low-k dielectric material can have different densities and different porosities.

[0024] "Complexing agents" as defined herein include those compounds that are understood by those skilled in the art to be complexing agents, chelating agents and / or chelating agents. Complexing agents will chemically combine with or physically grab the metal atoms and / or metal ions to be removed using the compositions described herein.

[0025] "Substantially free" is defined herein as less than 2 wt.%, preferably less than 1 wt.%, more preferably less than 0.5 wt.%, and most preferably less than 0.1 wt.%. "Free" is intended to correspond to less than 0.001 wt% to take environmental contamination into account.

[0026] As used herein, "about" is intended to correspond to ±5% of the stated value.

[0027] As used herein, "oxidizing agent" corresponds to a compound that oxidizes the exposed metal to corrode the metal or form an oxide on the metal. Oxidizing agents include, but are not limited to: hydrogen peroxide; other per compounds, such as salts and acids containing peroxymonosulfate, perborate, perchlorate, periodate, persulfate, permanganate, and peracetate anions; and amine-N-oxides.

[0028] As used herein, a "fluorine-containing compound" corresponds to a compound comprising a fluoride ion (F) ionically bonded to another atom. -) salt or acid compound.

[0029] The term "barrier material" as defined herein corresponds to any material used in the industry to seal metal lines (e.g., copper interconnects) to minimize diffusion of the metal (e.g., copper) into dielectric materials. Preferred barrier layer materials include tantalum, titanium, ruthenium, hafnium, tungsten, and other refractory metals and their nitrides and silicides.

[0030] For the purposes of the present invention, “degradation products of adenosine and adenosine derivatives” include, but are not limited to, adenine (C5H5N5), methylated adenine (e.g., N-methyl-7H-purin-6-amine, C6H7N5), dimethylated adenine (e.g., N,N-dimethyl-7H-purin-6-amine, C7H9N5), N4,N4-dimethylpyrimidine-4,5,6-triamine (C6H 11 N5), 4,5,6-triaminopyrimidine, allantoin (C4H6N4O3), hydroxylated COOC dimer ((C5H4N5O2)2), CC bridged dimer ((C5H4N5)2 or (C5H4N5O)2), ribose (C5H 10 O5), methylated ribose (e.g. 5-(methoxymethyl)tetrahydrofuran-2,3,4-triol, C6H 12 O5), tetramethylated ribose (e.g. 2,3,4-trimethoxy-5-(methoxymethyl)tetrahydrofuran, C9H 18 O5), and other ribose derivatives (e.g., methylated hydrolyzed diribose compounds).

[0031] As used herein, "surfactant" corresponds to an amphiphilic species having a hydrophobic group and a hydrophilic group, as is readily understood by those skilled in the art, but does not include a polymer. A "polymer" as defined herein corresponds to a species having a repeating monomer group 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.

[0032] As used herein, "suitability" for removing cerium oxide particles and CMP contaminants from a microelectronic device having the particles and contaminants thereon corresponds to at least partial removal of the particles / contaminants from the microelectronic device. Cleaning effectiveness is rated by the reduction of objects on the microelectronic device. For example, pre-cleaning and post-cleaning analysis can be implemented using an atomic force microscope. The particles on the sample can be recorded as a series of pixels. A histogram (e.g., Sigma Scan Pro) can be applied to filter pixels of a certain intensity (e.g., 231-235) and count the number of particles. Particle reduction can be calculated using the following formula:

[0033]

[0034] It should be noted that the method for determining cleaning efficiency is provided for example only and is not intended to be limited to this method. Alternatively, cleaning efficiency can be regarded as the percentage of the total surface covered by particulate matter. For example, the AFM can be programmed to perform a z-plane scan to identify the topographic area of ​​interest above a certain height threshold and then calculate the area of ​​the total surface covered by the area of ​​interest. It will be readily understood by those skilled in the art that the smaller the area covered by the area of ​​interest after cleaning, the more effective the removal composition. Preferably, at least 75% of the particles / contaminants are removed from the microelectronic device using the composition described herein, more preferably at least 90%, even more preferably at least 95%, and most preferably at least 99% of the particles / contaminants are removed.

[0035] The compositions described herein may be embodied in a wide variety of specific formulations, as more fully described below.

[0036] In all of the described compositions, where a specific component of the composition is discussed with reference to a weight percent range that includes a lower limit of zero, it is understood that the component may or may not be present in various specific embodiments of the composition and where the component is present, it may be present in a concentration as low as 0.00001 weight percent based on the total weight of the composition in which the component is employed.

[0037] In a first aspect, a removal composition is described, which in some embodiments is preferably an aqueous removal composition, comprising, consisting of, or consisting essentially of at least one pH adjuster, at least one reducing agent, at least one organic additive, optionally at least one complexing agent, optionally at least one polymer, and optionally at least one oxygen scavenger. In one embodiment of the first aspect, the removal composition comprises, consists of, or consists essentially of at least one pH adjuster, at least one reducing agent, and at least one organic additive. In another embodiment of the first aspect, the removal composition comprises, consists of, or consists essentially of at least one pH adjuster, at least one reducing agent, at least one organic additive, and at least one complexing agent. In another embodiment of the first aspect, the removal composition comprises, consists of, or consists essentially of at least one pH adjuster, at least one reducing agent, at least one organic additive, and at least one polymer. In another embodiment of the first aspect, the removal composition comprises, consists of, or consists essentially of at least one pH adjuster, at least one reducing agent, at least one organic additive, and at least one oxygen scavenger. In another embodiment of the first aspect, the removal composition comprises, consists of, or consists essentially of at least one pH adjuster, at least one reducing agent, at least one organic additive, and at least one complexing agent. In another embodiment of the first aspect, the removal composition comprises, consists of or consists essentially of at least one pH adjusting agent, at least one reducing agent, at least one organic additive, at least one complexing agent and at least one polymer. In another embodiment of the first aspect, the removal composition comprises, consists of or consists essentially of at least one pH adjusting agent, at least one reducing agent, at least one organic additive, at least one polymer and at least one oxygen scavenger. In another embodiment of the first aspect, the removal composition comprises, consists of or consists essentially of at least one pH adjusting agent, at least one reducing agent, at least one organic additive, at least one complexing agent, at least one polymer and at least one oxygen scavenger. It will be appreciated by those skilled in the art that the aqueous cleaning composition described herein further comprises water, preferably deionized water.

[0038] In each embodiment, before the residual material is removed from the microelectronic device, the removal composition may be substantially free of at least one of the following: an oxidant; a fluorine-containing source; a surfactant; tetramethylammonium hydroxide; a chemical mechanical polishing abrasive material (e.g., silicon dioxide, aluminum oxide, etc.); and a corrosion inhibitor selected from the group consisting of cyanuric acid, barbituric acid and its derivatives, glucuronic acid, squaric acid, α-keto acid, adenosine and its derivatives, ribosyl purine and its derivatives, purine compounds and its derivatives, degradation products of adenosine and adenosine derivatives, triaminopyrimidine and other substituted pyrimidines, purine-sugar complexes, phosphonic acid and its derivatives, phenanthroline, glycine, nicotinamide and its derivatives, flavonoids (e.g., flavonols and anthocyanins and their derivatives), quercetin and its derivatives, and combinations thereof. In addition, the removal composition should not cure to form a polymeric solid, including, for example, a photoresist.

[0039] The complexing agent, if present, comprises a compound having the general formula NR 1 R 2 R 3 species, among which R 1 , R 2 and R 3 The radicals R and R are identical or different from each other and are selected from the group consisting of hydrogen, linear or branched C1-C6 alkyl (e.g., methyl, ethyl, propyl, butyl, pentyl and hexyl), linear or branched C1-C6 hydroxyalkyl (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl and hydroxyhexyl), and C1-C6 alkyl ethers of linear or branched C1-C6 hydroxyalkyl as defined above. Most preferably, R 1 , R 2 and R 3 At least one of is a linear or branched C1-C6 hydroxyalkyl. 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, other C1-C8 alkanolamines, and combinations thereof. When the amine comprises an alkyl ether component, the amine may be considered an alkoxyamine, such as 1-methoxy-2-aminoethane. Alternatively or in addition to NR 1 R 2 R 3In addition to amines, the complexing agent can be a multifunctional amine, including (but not limited to) 4-(2-hydroxyethyl)morpholine (HEM), 1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid (CDTA), ethylenediaminetetraacetic acid (EDTA), m-xylenediamine (MXDA), iminodiacetic acid (IDA), 2-(hydroxyethyl)iminodiacetic acid (HIDA), nitrilotriacetic 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, and combinations thereof. Alternatively or in addition to the complexing agents mentioned above, other complexing agents may include phosphonic acids (e.g., 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), 1,5,9-triazacyclododecane-N,N',N"-tri(methylenephosphonic acid) (DOTRP), 1,4,7,10-tetraazacyclododecane-N,N',N",N'"-tetra(methylenephosphonic acid) (DOTP), nitrogen tris(methylene) triphosphonic acid, diethylenetriamine penta(methylenephosphonic acid) (DETAP), aminotris(methylenephosphonic acid), bis(hexamethylene) triamine penta(methylenephosphonic acid), 1,4,7-triazacyclononane-N,N',N"-tris ... (methylenephosphonic acid) (NOTP), bisphosphonic acid hydroxyethyl ester, nitrogen tris (methylene) phosphonic acid, 2-phosphono-butane-1,2,3,4-tetracarboxylic acid, carboxyethylphosphonic acid, aminoethylphosphonic acid, glyphosate, ethylenediamine tetra (methylenephosphonic acid) phenylphosphonic acid, its salts and derivatives thereof) 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, trimethylol propionic acid, tartaric acid, glucuronic acid, 2-carboxypyridine) and / or sulfonic acids (e.g., tryptone (4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt)). Preferably, at least one complexing agent comprises a species selected from the group consisting of monoethanolamine, triethanolamine, sulfuric acid, citric acid and combinations thereof. If present, the amount of complexing agent in the removal composition ranges from about 0.01 wt % to about 10 wt % based on the total weight of the removal composition.

[0040] The pH adjuster includes an acid and / or a base. The base includes, but is not limited to, an alkali metal hydroxide (e.g., LiOH, KOH, RbOH, CsOH), an alkaline earth metal hydroxide (e.g., Be(OH)2, Mg(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2), ammonium hydroxide (i.e., ammonia), and a base having the formula NR 1 R 2 R 3 R 4 OH tetraalkylammonium hydroxide compounds, wherein R1 , R 2 , R 3 and R 4 The alkyl radicals may be the same as or different from each other and are selected from the group consisting of hydrogen, a linear or branched C1-C6 alkyl radical (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl), a C1-C6 hydroxyalkyl radical (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, and hydroxyhexyl), and a substituted or unsubstituted C6-C 10 Aryl (e.g., benzyl). Commercially available tetraalkylammonium hydroxides can be used, including 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, the pH adjuster may be a compound having the formula (PR 1 R 2 R 3 R 4 )OH quaternary base, where R 1 , R 2 , R 3 and R 4 The alkyl radicals 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 C1-C6 alkyl, C1-C6 hydroxyalkyl (e.g., hydroxymethyl, hydroxyethyl, hydroxypropyl, hydroxybutyl, hydroxypentyl, and hydroxyhexyl), substituted C6-C 10 Aryl, unsubstituted C6-C 10Aryl (e.g., benzyl) and any combination thereof, such as tetrabutylphosphonium hydroxide (TBPH), tetramethylphosphonium hydroxide, tetraethylphosphonium hydroxide, tetrapropylphosphonium hydroxide, benzyltriphenylphosphonium hydroxide, methyltriphenylphosphonium hydroxide, ethyltriphenylphosphonium hydroxide, 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 includes KOH. In another embodiment, the pH adjuster includes choline hydroxide. In another embodiment, the pH adjuster includes ammonium hydroxide. In another embodiment, the pH adjuster includes at least one alkali metal hydroxide and at least one other hydroxide listed herein. In another embodiment, the pH adjuster includes KOH and at least one other hydroxide listed herein. In another embodiment, the pH adjuster includes KOH and at least one of choline hydroxide and ammonium hydroxide. With regard to any of the enumerated embodiments, the pH adjuster can further comprise at least one acid, such as sulfuric acid, citric acid, or a combination of citric acid and sulfuric acid.

[0041] Contemplated organic additives include, but are not limited to, 2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone (HEP), glycerol, 1,4-butanediol, tetrahydrothiophene sulfolane (sulfolane), dimethyl sulfone, ethylene glycol, propylene glycol, dipropylene glycol, tetraglycinyl dimethyl ether, diglycinyl dimethyl ether, methyl isobutyl ketone, methyl ethyl ketone, acetone, isopropanol, octanol, ethanol, butanol, methanol, isophorone, glycol ethers (e.g., diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropylene glycol, propylene glycol monomethyl ether, propylene ... ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (DEGBE), triethylene glycol monobutyl ether (TEGBE), ethylene glycol monohexyl ether (EGHE), diethylene glycol monohexyl ether (DEGHE), ethylene glycol phenyl ether, diethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (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 (e.g. DOWANOL PnB), dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, dipropylene glycol phenyl ether, propylene glycol phenyl ether (PPh, e.g. DOWANOL PPh), 4-methyl-2-pentanone, 2,4-dimethyl-3-pentanone, cyclohexanone, 5-methyl-3-heptanone, 3-pentanone, 5-hydroxy-2-pentanone, 2,5-hexanedione, 4-hydroxy-4-methyl-2-pentanone, acetone, butanone, 2-methyl-2-butanone, 3,3-dimethyl-2-butanone, 4-hydroxy-2-butanone, cyclopentanone, 2-pentanone, 3-pentanone, 1-phenylacetone, acetophenone, benzophenone , 2-hexanone, 3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 4-octanone, dicyclohexyl ketone, 2,6-dimethylcyclohexanone, 2-acetylcyclohexanone, 2,4-pentanedione, menthone, monoethanolamine (MEA), and combinations thereof. In a preferred embodiment, the at least one organic additive in the removal composition comprises at least one glycol ether, including propylene glycol phenyl ether.

[0042] The polymer, if present, includes, but is not limited to, homopolymers and copolymers of methacrylic acid with, for example, acrylamidomethylpropanesulfonic acid and maleic acid; maleic acid / vinyl ether copolymers; poly(vinyl pyrrolidone) / vinyl acetate; homopolymers, such as phosphonated polyethylene glycol oligomers, poly(acrylic acid) (PAA), poly(acrylamide), poly(vinyl acetate), poly(ethylene glycol) (PEG), poly(propylene glycol) (PPG), poly(styrene sulfonic acid), poly(vinyl sulfonic acid), poly(vinyl phosphonic acid), poly(vinyl phosphoric acid), poly(ethylene imine), poly(propylene imine), polyallylamine, polyethylene oxide (PEO), polyvinyl pyrrolidone (PVP); PPG-PEG-PPG block copolymers; PEG-PPG-PEG block copolymers; and combinations thereof. If present, the amount of polymer in the removal composition ranges from about 0.0001 wt % to about 1 wt % based on the total weight of the removal composition.

[0043] Oxygen scavengers, if present, include, but are not limited to, dialkylhydroxylamines, hydroxyalkylhydroxylamines, carbohydrazides, 2-aminoethylpiperazine (AEP), methylethylketoxime, hydroquinone, hydrazine, 1,3-cyclohexanedione, 1,4-cyclohexanedione and 2,5-cyclohexanedione, alone or in combination with 3-methoxypropylamine, aminophenols, linear water-soluble polyethyleneamines (e.g., triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine), sodium sulfite, ammonium sulfite, potassium sulfite, and combinations thereof. Preferably, the oxygen scavenger includes carbohydrazides, 2-aminoethylpiperazine (AEP), methylethylketoxime, hydroquinone, hydrazine, 1,3-cyclohexanedione, 1,4-cyclohexanedione and 2,5-cyclohexanedione, alone or in combination with 3-methoxypropylamine, aminophenols, linear water-soluble polyethyleneamines (e.g., triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine), and combinations thereof. Without being bound by theory, it is believed that the oxygen scavenger helps stabilize the reducing agent.If present, the amount of oxygen scavenger in the removal composition ranges from about 0.0001 wt% to about 1 wt% based on the total weight of the removal composition.

[0044] Reducing agents include, but are not limited to, ascorbic acid, L(+)-ascorbic acid, isoascorbic acid, ascorbic acid derivatives, sulfurous acid, ammonium sulfite, potassium sulfite, sodium sulfite, dopamine HCl, phosphoric acid, phosphinic acid, potassium pyrosulfite, sodium pyrosulfite, ammonium pyrosulfite, hydroxylamine, reducing sugars (e.g., galactose, ribose, arabinose, xylose, fucose, rhamnose, mannose, fructose, sorbose, galacturonic acid, glucosamine, maltose, lactose), potassium pyruvate, sodium pyruvate, ammonium pyruvate, formic acid, sodium formate, potassium formate, ammonium formate, dopamine, sulfur dioxide solution, and any combination thereof. Preferably, at least one reducing agent includes at least one sulfite ion and at least one other listed reducing agent, such as sulfurous acid, potassium sulfite, ammonium sulfite, phosphinic acid, and any combination thereof. It should be appreciated that when ammonium sulfite is present, the ammonium sulfite may be generated in situ, wherein a combination of specific components form the ammonium sulfite to aid in the removal of residues, such as cerium oxide particles and other post-CMP residues.

[0045] The aqueous removal compositions comprising the components described above are particularly useful for removing cerium oxide particles and contaminants (e.g., post-CMP residues and contaminants) from microelectronic device structures. The pH of the aqueous removal compositions described herein may range from about 1 to about 13.9. In one embodiment, the pH is in the range of about 3 to about 13.9, preferably about 3.5 to about 13.9. In another embodiment, the pH is in the range of about 3.5 to about 5.5. In another embodiment, the pH is in the range of about 4.5 to about 8.5, preferably about 7.5 to 8.5. In another embodiment, the pH is in the range of about 9 to about 13.7.

[0046] In a particularly preferred embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a reducing agent, at least one pH adjusting agent, at least one organic additive, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a compound comprising sulfite ions, at least one pH adjusting agent, at least one organic additive, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a reducing agent, at least one pH adjusting agent, propylene glycol phenyl ether, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a compound comprising sulfite ions, at least one pH adjusting agent, propylene glycol phenyl ether, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a reducing agent, at least one complexing agent, at least one pH adjusting agent, at least one organic additive, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a compound comprising sulfite ions, at least one complexing agent, at least one pH adjusting agent, at least one organic additive, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a compound comprising a sulfite ion, citric acid, at least one pH adjuster, at least one organic additive, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a compound comprising a sulfite ion, citric acid, at least one pH adjuster, propylene glycol phenyl ether, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a reducing agent (e.g., a compound comprising a sulfite ion), at least one pH adjuster, at least one organic additive, at least one oxygen scavenger, and water. In another embodiment, the aqueous removal composition comprises, consists of, or consists essentially of a reducing agent (e.g., a compound comprising a sulfite ion), at least one pH adjuster, at least one organic additive, at least one complexing agent (e.g., citric acid), at least one oxygen scavenger, and water.

[0047] Regarding composition amounts, the weight % ratio of the organic additive to the reducing agent ranges from about 0.001: 1 to about 10: 1, preferably from about 0.1: 1 to about 5: 1. Based on the pH values ​​disclosed herein and the knowledge of those skilled in the art, the amount of pH adjuster is determined according to the final pH sought when preparing the removal composition for use.

[0048] The range of weight % ratios of the components will cover all possible concentrated or dilute embodiments of the composition. To this end, in one embodiment, a concentrated removal composition is provided that can be diluted for use as a cleaning solution. A concentrated composition or "concentrate" advantageously allows a user (e.g., a CMP process engineer) to dilute the concentrate to a desired strength and pH at the time of use. The dilution of the concentrated aqueous removal composition can range from about 1:1 to about 2500:1, preferably about 5:1 to about 200:1, and most preferably about 20:1 to about 120:1, wherein the aqueous removal composition is diluted with a solvent (e.g., deionized water) at or slightly before the tool. It should be understood by those skilled in the art that the range of weight % ratios of the components disclosed herein should remain unchanged after dilution.

[0049] The compositions described herein can be used in a variety of applications, including but not limited to post-etch residue removal, post-ash residue removal surface preparation, post-plating cleaning, and post-CMP residue removal. In addition, it is contemplated that the aqueous cleaning compositions described herein can be used to clean and protect other metal (e.g., copper-containing and tungsten-containing) products, including but not limited to decorative metals, metal bonding, printed circuit boards, and other electronic packaging using metals or metal alloys.

[0050] In another preferred embodiment, the aqueous 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 begins and will be dissolved and / or suspended in the composition.

[0051] The aqueous removal compositions are readily formulated by simply adding the respective ingredients and mixing to a homogeneous state. In addition, the compositions can be readily formulated as single-package formulations or multi-part formulations that are mixed at the time of use or prior to use, for example, the individual parts of the multi-part formulation can be mixed at the tool or in a storage tank upstream of the tool. The concentrations of the respective ingredients can vary widely in a variety of specific compositions, i.e., more dilute or more concentrated, and it should be understood that the compositions described herein can variably and alternatively comprise, consist of, or consist essentially of any combination of ingredients consistent with the disclosure herein.

[0052] Therefore, another aspect relates to a kit comprising one or more components suitable for forming the compositions described herein in one or more containers. The kit may comprise 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 in one or more containers for combination with other solvents (e.g., water) at a wafer fabrication plant (fab) or at the time of use. Alternatively, the kit may comprise 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 in one or more containers for combination with at least one pH adjuster and other solvents (e.g., water) at a wafer fabrication plant or at the time of use. The container of the kit must be suitable for storing and transporting the composition and may be, for example Container (Entegris, Inc., Billerica, Mass., USA).

[0053] The one or more containers containing the components of the aqueous removal composition preferably include means for fluidly connecting the components in the one or more containers for mixing and dispensing. When a container is used, gas pressure can be applied to the exterior of the liner in the one or more containers to discharge at least a portion of the contents of the liner and thereby achieve fluid communication for blending and dispensing. Alternatively, gas pressure can be applied to the headspace of a conventional pressurizable container or a pump can be used to achieve fluid communication. In addition, the system preferably includes a dispensing port for dispensing the blended removal composition to a process tool.

[0054] When applied to microelectronic manufacturing operations, the aqueous removal compositions described herein can be used to clean cerium oxide particles and / or CMP contaminants (e.g., post-CMP residues and contaminants) from the surface of a microelectronic device. The aqueous removal compositions do not damage low-k dielectric materials (e.g., silicon oxide), silicon nitride layers, or tungsten-containing layers on the surface of the device. Preferably, the aqueous removal composition removes at least 85% of the cerium oxide particles present on the device prior to removing the particles, more preferably at least 90%, even more preferably at least 95%, and most preferably at least 99%.

[0055] In post-CMP particle and contaminant removal applications, the aqueous removal compositions described herein can be used with a wide variety of conventional cleaning tools such as megasonic and brush cleaning, including but not limited to Verteq single wafer megasonic gold fingers, OnTrak system DDS (double-sided scrubber), SEZ or other single wafer spray cleaning, Applied Materials Mirra-Mesa TM / Reflexion TM / Reflexion LK TMand Megasonic batch wet cleaning benchtop systems.

[0056] In removing cerium oxide particles and CMP contaminants from a microelectronic device having the particles and contaminants thereon using the compositions described herein, the aqueous removal composition is typically contacted with the device at a temperature ranging from about 20° C. to about 90° C., preferably from about 20° C. to about 50° C., for a time of about 5 seconds to about 10 minutes, preferably from about 1 second to 20 minutes, preferably from about 15 seconds to about 5 minutes. The contact times and temperatures are illustrative, and any other suitable time and temperature conditions that are effective within the broad practice of the method to at least partially remove cerium oxide particles and CMP contaminants from the device may be employed. "At least partially cleaning" and "substantially removing" correspond only to removing at least 85% of the cerium oxide particles present on the device prior to particle removal, more preferably at least 90%, even more preferably at least 95%, and most preferably at least 99%.

[0057] After achieving the desired particle removal effect, the aqueous removal composition can be easily removed from the device to which it has been previously applied, as may be necessary and effective in a given end-use application of the composition described herein. Preferably, the cleaning solution comprises deionized water. Thereafter, the device can be dried using nitrogen or a spin-dry cycle.

[0058] Another aspect relates to improved microelectronic devices made according to the methods described herein and products containing the same.

[0059] Another aspect involves recycling the aqueous removal composition, wherein the removal composition can be recirculated until the particle and / or contaminant load reaches a maximum amount that the aqueous removal composition can accommodate, as readily determined by one skilled in the art.

[0060] Another aspect relates to a method of making an article including a microelectronic device, the method comprising contacting the microelectronic device with an aqueous removal composition for a sufficient time to remove cerium oxide particles and CMP contaminants from the microelectronic device having thereon the particles and contaminants using the removal composition described herein and incorporating the microelectronic device into the article.

[0061] In another aspect, a method of removing cerium oxide particles and CMP contaminants from a microelectronic device having the particles and contaminants thereon is described. The method comprises polishing the microelectronic device with a CMP slurry, wherein the CMP slurry comprises cerium oxide particles; contacting the microelectronic device with an aqueous removal composition for a sufficient time to remove the cerium oxide particles and CMP contaminants from the microelectronic device to form a composition containing post-CMP particles, the 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; and contacting the microelectronic device with the composition containing post-CMP particles continuously for a sufficient amount of time to achieve substantial cleaning of the microelectronic device. Any of the components described above may be used in the present method of removing cerium oxide particles and CMP contaminants.

[0062] Another aspect relates to an article comprising an aqueous removal composition, a microelectronic device wafer, and a material selected from the group consisting of cerium oxide particles, CMP contaminants, and combinations thereof, wherein the removal composition comprises 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.

[0063] The features and advantages of the present invention are more fully illustrated by the following non-limiting examples, in which all parts and percentages are by weight unless otherwise expressly stated.

[0064] Example 1

[0065] The removal compositions shown below were prepared (the balance in each formulation was DI water) and diluted 100:1 with water. The process involved immersing the TEOS substrate in a slurry containing ceria for 5 minutes, rinsing the substrate in DI water for 30 seconds, immersing the substrate in the removal composition for 60 seconds, and then rinsing with DI water for 30 seconds. The temperature during immersion was room temperature. The extent of cleaning was determined using scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and dark field microscopy (DFM), and compared with Comparative Formulation 1.

[0066] Formulation A: 2 wt% citric acid, 2 wt% propylene glycol phenyl ether, balance water. pH after adjustment and 1:100 dilution = 2.5

[0067] Formulation B: 2 wt% citric acid, 2 wt% sodium sulfite, balance water. pH after adjustment and 1:100 dilution = 2.6

[0068] Formulation C: 2 wt% citric acid, 2 wt% propylene glycol phenyl ether, 2 wt% sodium sulfite, balance water. pH after adjustment and 1:100 dilution = 2.6

[0069] Comparative formulation 1: NH4OH:H2O2:H2O=1:1:5

[0070] The DFM data indicates the total area of ​​cerium oxide contamination after cleaning. Formulations AC were all found to be more effective at cleaning than Comparative Formulation 1. Specifically, Formulation C was found to be 3.5× more effective than the Comparative Formulation and 2× more effective than Formulation A.

[0071] Based on the effectiveness of Formulation C, other compositions were prepared and DFM data were determined as shown in Table 1. The balance in each formulation was DI water. KOH was added to adjust the pH to the target pH. The formulations were diluted 100:1 with water and a TEOS substrate including a cerium oxide slurry was immersed therein for 5 minutes at room temperature.

[0072] Table 1: Formulation and DFM data

[0073]

[0074] Formulation J was found to have a 150x improved performance over Comparative Formulation 1. Formulations D, F, H, I and NR were also more effective at cleaning than the Comparative Formulation. It should be noted that these formulations have a higher pH ranging from 4-6.

[0075] Example 2

[0076] The removal compositions shown below were prepared (the balance in each formulation was DI water) and diluted 100:1 with water. The process involved immersing the TEOS substrate in a slurry containing cerium oxide for 5 minutes, rinsing the substrate in DI water for 30 seconds, immersing the substrate in the removal composition for 60 seconds, and then rinsing it with DI water for 30 seconds. The temperature during immersion was room temperature. The degree of cleaning was determined using scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and dark field microscopy (DFM). Specifically, Table 2 shows the DMF data for each removal composition.

[0077] Table 2: Formulation and DFM data

[0078]

[0079]

[0080] Although the illustrative embodiments and features of the present invention have been disclosed herein, it should be understood that the embodiments and features described above are not intended to limit the present invention, and other variations, modifications and other embodiments will be apparent to those skilled in the art based on the disclosure herein. Therefore, the present invention should be broadly understood to include all such variations, modifications and alternative embodiments within the spirit and scope of the appended claims.

Claims

1. An aqueous removal composition for removing cerium oxide particles from the surface of a microelectronic device after chemical mechanical polishing (CMP), the aqueous removal composition comprising at least one pH adjuster, at least one reducing agent, at least one organic additive, water and at least one oxygen scavenger, wherein the aqueous removal composition contains less than 0.001 wt.% of a surfactant, wherein the at least one organic additive and the at least one reducing agent are present in a weight percent ratio of from 0.1:1 to 5:1, and The at least one organic additive is 2-pyrrolidone, 1-(2-hydroxyethyl)-2-pyrrolidone (HEP), tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, methyl isobutyl ketone, methyl ethyl ketone, acetone, isopropanol, octanol, ethanol, butanol, methanol, isophorone, 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 (DEGBE), triethylene glycol monobutyl ether (TEGBE), ethylene glycol monohexyl ether (EGHE), diethylene glycol monohexyl ether (DEGHE), ethylene glycol phenyl ether, diethylene glycol phenyl ether, 4-methyl-2-pentanone, 2,4- dimethyl-3-pentanone, cyclohexanone, 5-methyl-3-heptanone, 3-pentanone, 5-hydroxy-2-pentanone, 2,5-hexanedione, 4-hydroxy-4-methyl-2-pentanone, acetone, butanone, 2-methyl-2-butanone, 3,3-dimethyl-2-butanone, 4-hydroxy-2-butanone, cyclopentanone, 2-pentanone, 3-pentanone, 1-phenylacetone, acetophenone, benzophenone, 2-hexanone, 3-hexanone, 2-heptanone, 3-heptanone, 4-heptanone, 2,6-dimethyl-4-heptanone, 2-octanone, 3-octanone, 4-octanone, dicyclohexanone, 2,6-dimethylcyclohexanone, 2-acetylcyclohexanone, 2,4-pentanedione, menthone, or a combination thereof, The pH value of the aqueous removal composition is 4 to 6.

2. The aqueous removal composition according to claim 1, further comprising at least one complexing agent for complexing metal atoms or metal ions.

3. The aqueous removal composition of claim 1 or 2, further comprising at least one polymer.

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