Nitride etchant compositions and methods

Abstract

A method for selectively etching titanium nitride compositions is provided that generally leave the molybdenum present and any aluminum oxide, silicon dioxide, and polysilicon that may be present on the device unaffected by the process. The compositions of the invention are generally capable of achieving titanium nitride etch rates exceeding 1000 Å / min, thereby providing uniform recessed top and bottom layers in the pattern.

Description

Technical Field

[0001] The present invention relates generally to the field of semiconductor manufacturing and more particularly to a method for etching titanium nitride films on microelectronic devices. Background Art

[0002] Photoresist masks are commonly used in the semiconductor industry to pattern materials such as semiconductors or dielectrics. In one application, photoresist masks are used in a dual damascene process to form interconnects in a back-end metal process of a microelectronic device. The dual damascene process involves forming a photoresist mask on a low-k dielectric layer overlying a metal conductor layer (such as a copper layer). The low-k dielectric layer is then etched according to the photoresist mask to form vias and / or trenches that expose the metal conductor layer. The vias and trenches, commonly referred to as dual damascene structures, are typically defined using two photolithography steps. The photoresist mask is then removed from the low-k dielectric layer, after which a conductive material is deposited into the vias and / or trenches to form interconnects.

[0003] As the size of microelectronic devices decreases, it becomes increasingly difficult to achieve critical dimensions of through holes and trenches. Therefore, metal hard masks are used to provide optimal profile control of through holes and trenches. The metal hard mask can be made of titanium or titanium nitride and is removed by a wet etching process after forming the through holes and / or trenches of the dual damascene structure. The wet etching process must use a removal chemistry that effectively removes the metal hard mask and / or photoresist etch residue without affecting the underlying metal conductor layer and low-k dielectric material or other materials on the microelectronic device. Specifically, there is a need for a composition that can be used in a wet etching process that selectively removes substances such as titanium nitride while being compatible with metal conductive layers such as molybdenum, AlOx, SiOx, and polysilicon that may also be present on the microelectronic device. Summary of the invention

[0004] The present invention generally provides a method for producing a composition of molybdenum recesses in a microelectronic device structure, such as a 3D NAND flash memory device. In this method, a first step involves removing a molybdenum layer using a high selectivity molybdenum etchant that exhibits a higher selectivity to molybdenum than titanium nitride also present on the microelectronic device. This first step is known and can be characterized as a dry or wet etching process (see, for example, IEEE Transactions on Electronic Devices, Vol. 51, No. 12, December 2004). In a second step, in one embodiment of the present invention, the titanium nitride layer is selectively etched, typically leaving the molybdenum present and any aluminum oxide, silicon dioxide, and polysilicon that may be present on the device unaffected by the process. The present compositions are typically capable of achieving over 100% etching. / min titanium nitride etch rate, thereby providing uniform recessed top and bottom layers in the pattern. In addition, the composition is very stable, for example, bath life exceeds 24 hours and shelf life exceeds 6 months.

[0005] Therefore, in a first aspect, the present invention provides a composition comprising:

[0006] a.water;

[0007] b. at least one oxidizing agent;

[0008] c. at least one fluoride-containing etchant;

[0009] d. at least one metal corrosion inhibitor;

[0010] e. at least one pH adjusting agent; and optionally

[0011] f. at least one water-miscible solvent.

[0012] The composition is suitable for selectively etching titanium nitride. The selectivity of the composition depends on the process temperature and time (ie, exposure). In one embodiment, the selectivity of titanium nitride etching relative to molybdenum is about 5 to 25 when measured at about 50° C. for 5 minutes. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 Flow chart of the method of the present invention. Starting with a device structure having a gate material comprising tungsten and molybdenum, the device structure is subjected to, for example, a dry etching (or wet etching) technique to provide a gate metal recess. Subsequently, a barrier metal such as titanium nitride and / or tantalum nitride is etched. This selectivity for removing titanium nitride and tantalum nitride is compatible with existing gate materials (such as tungsten or molybdenum) and high-k materials (such as AlOx or ZrOx). DETAILED DESCRIPTION

[0014] In a first aspect, the present invention provides a composition comprising:

[0015] a.water;

[0016] b. at least one oxidizing agent;

[0017] c. at least one fluoride-containing etchant;

[0018] d. at least one metal corrosion inhibitor;

[0019] e. at least one pH adjusting agent; and optionally

[0020] f. at least one water-miscible solvent.

[0021] As used herein, the term "microelectronic device" corresponds to semiconductor substrates, flat panel displays, phase change memory devices, solar panels, and other products (including solar cell devices, photovoltaic devices, and microelectromechanical systems (MEMS)) manufactured for use in microelectronics, integrated circuits, energy harvesting, or computer chip applications. It should be understood that the terms "microelectronic device," "microelectronic substrate," and "microelectronic device structure" are not meant to be limiting in any way and include any substrate or structure that will eventually become a microelectronic device or microelectronic assembly. The microelectronic device may be patterned, covered, a control, and / or a test device.

[0022] As used herein, the terms "titanium nitride" and "TiN x " corresponds to pure titanium nitride and impure titanium nitride (i.e., TiO x N y ).

[0023] As used herein, "about" means corresponding to + or - 0.5% of the stated value.

[0024] As used herein, the term "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. In certain embodiments, the low-k dielectric material includes a low polarity material such as silicon-containing organic polymers, silicon-containing organic / inorganic hybrid materials, organosilicate glass (OSG), TEOS, fluorinated silicate glass (FSG), silicon dioxide, aluminum oxide (AlO x )、ZrO x ) and carbon doped oxide (CDO) glass. It should also be understood that low-k dielectric materials may have different densities and different porosities.

[0025] As used herein, the term "metal conductor layer" includes copper, tungsten, cobalt, molybdenum, aluminum, ruthenium, alloys thereof, and combinations thereof.

[0026] As used herein, a "fluoride" species corresponds to a compound including the fluoride ion (F - ) or covalently bonded fluorine species. It should be understood that the fluoride species can be included in the fluoride species or generated in situ.

[0027] As described more fully below, the compositions of the present invention may be embodied in a wide variety of specific formulations.

[0028] In all such compositions, where specific components of the composition are discussed with reference to weight percent ranges (including a lower limit of zero), it is understood that such components may or may not be present in various specific embodiments of the composition, and where such components are present, they may be present at a concentration as low as 0.0001 weight percent, based on the total weight of the composition in which such components are employed.

[0029] Etching agents are added to increase the etching rate of titanium nitride. Etching agents considered include, but are not limited to, fluoride sources such as HF, ammonium fluoride, tetrafluoroboric acid, hexafluorosilicic acid, other compounds containing B--F or Si--F bonds, tetrabutylammonium tetrafluoroborate (TBA-BF 4 ), tetraalkylammonium fluoride (NR 1 R 2 R 3 R 4 F); strong bases, such as tetraalkylammonium hydroxide (NR 1 R 2 R 3 R 4 OH), where R 1 , R 2 , R 3 , R 4 may be the same as or different from each other and are selected from hydrogen, linear or branched C 1 -C 6 Alkyl (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl), C 1 -C 6 Alkoxy (e.g., hydroxyethyl, hydroxypropyl), substituted or unsubstituted aryl (e.g., benzyl); weak base; and combinations thereof. In one embodiment, the fluoride source comprises HF, tetrafluoroboric acid, hexafluorosilicic acid, H 2 ZF 6 , H 2 TiF 6 , HPF 6 , ammonium fluoride, tetramethylammonium fluoride, ammonium hexafluorosilicate, ammonium hexafluorotitanate, or a combination of ammonium fluoride and tetramethylammonium fluoride. In another embodiment, the etchant comprises HF, hexafluorosilicic acid, or tetrafluoroboric acid. In yet another embodiment, the etchant is HF.

[0030] An oxidizing agent is included to etch or oxidize TiN x Ti in the film 3+ The oxidizing agents contemplated herein include, but are not limited to, hydrogen peroxide (H 2 O 2 ), FeCl 3 , FeF 3 、Fe(NO 3 ) 3 、Sr(NO 3 ) 2 , CoF 3 、MnF 3 , (2KHSO 5 ·KHSO 4 ·K 2 SO4 -CAS No. 70693-62-8), periodic acid, iodic acid, tert-butyl hydroperoxide, vanadium (V) oxide, vanadium (IV, V) oxide, ammonium vanadate, polyatomic ammonium salts (e.g., ammonium peroxymonosulfate, ammonium chlorite (NH 4 C1O 2 ), ammonium chlorate (NH 4 C1O 3 ), ammonium iodate (NH 4 IO 3 ), ammonium nitrate (NH 4 NO 3 ), ammonium perborate (NH 4 BO 3 ), ammonium perchlorate (NH 4 C1O 4 ), ammonium periodate (NH 4 IO 4 ), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), ammonium hypochlorite (NH 4 ClO)), ammonium tungstate ((NH 4 ) 10 H 2 (W 2 O 7 )), polyatomic sodium salts (e.g. sodium persulfate (Na 2 S 2 O 8 ), sodium hypochlorite (NaClO), sodium perborate), polyatomic potassium salts (e.g. potassium iodate (KIO 3 ), potassium permanganate (KMnO 4 ), potassium persulfate, nitric acid (HNO 3 ), potassium persulfate (K 2 S 2 O 8 ), potassium hypochlorite (KClO), polyatomic tetramethylammonium salts (e.g., tetramethylammonium chlorite ((N(CH 3 ) 4 )ClO 2 ), tetramethylammonium chlorate ((N(CH 3 ) 4 )ClO 3 ), tetramethylammonium iodide ((N(CH 3 ) 4 )IO 3 ), tetramethylammonium perborate ((N(CH 3 ) 4 )BO 3 ), tetramethylammonium perchlorate ((N(CH 3 )4 )ClO 4 ), tetramethylammonium periodate ((N(CH 3 ) 4 )IO 4 ), tetramethylammonium persulfate ((N(CH 3 ) 4 )S 2 O 8 )), polyatomic tetrabutylammonium salts (e.g., tetrabutylammonium peroxymonosulfate), peroxymonosulfuric acid, ferric nitrate (Fe(NO 3 ) 3 ), carbamide peroxide ((CO(NH 2 ) 2 )H 2 O 2 ), peracetic acid (CH 3 (CO)OOH), 1,4-benzoquinone, toluenequinone, dimethyl-1,4-benzoquinone, chloranil, alloxan, and combinations thereof. When the oxidant is a salt, it may be hydrated or anhydrous. The oxidant may be introduced into the composition at the manufacturer, before the composition is introduced into the device wafer, or alternatively at the device wafer (i.e., in situ). In one embodiment, the oxidant comprises periodic acid.

[0031] Metal corrosion inhibitors are added to block the oxidizing activity of the oxidant. Metal corrosion inhibitors contemplated herein include, but are not limited to, 5-amino-1,3,4-thiadiazole-2-thiol (ATDT), benzotriazole (BTA), 1,2,4-triazole (TAZ), tolyltriazole, 5-methyl-benzotriazole (MBTA), 5-phenyl-benzotriazole, 5-nitro-benzotriazole, benzotriazole carboxylic acid, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 2-(5-amino-pentyl)-benzotriazole, 1-amino-1,2,3-triazole, 1-amino-5-methyl-1,2,3-triazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 3-isopropyl-1,2,4-triazole, 5-benzenethiol-benzotriazole, Halogenated-benzotriazole (halogen = F, Cl, Br or I), naphthotriazole, 2-mercaptobenzimidazole (MBI), 2-mercaptobenzothiazole, 4-methyl-2-phenylimidazole, 2-mercaptothiazoline, 5-aminotetrazolyl, pentene tetrazole, 5-phenyl-1H-tetrazole, 5-benzyl-1H-tetrazole, succinimide, 2,4-diamino-6-methyl-1,3,5-triazine, thiazole, triazine, methyltetrazole, 1,3-dimethyl-2-imidazolidinone, 1,5-pentamethylenetetrazole, 1-phenyl-5-mercaptotetrazole, diaminomethyltriazine, imidazolinethione, 4-methyl-4H-1,2,4-triazole-3-thiol, benzothiazole, imidazole, indiazole, adenosine, carbazole, o-sulfonylbenzoimide, benzoin oxime and combinations thereof.Additional corrosion inhibitors include cationic quaternary salts such as benzalkonium chloride, benzyldimethyldodecyl ammonium chloride, myristyltrimethylammonium bromide, dodecyltrimethylammonium bromide, cetylpyridinium chloride, Aliquat 336 (Cognis), benzyldimethylphenylammonium chloride, Crodaquat TES (Croda Inc.), Rewoquat CPEM (Witco), cetyltrimethylammonium p-toluenesulfonate, cetyltrimethylammonium hydroxide, 1-methyl-1'-tetradecyl-4,4'-bipyridinium dichloride, alkyltrimethylammonium bromide, amprolium hydrochloride, benzethonium hydroxide hydroxide), benzethonium chloride, benzyldimethylhexadecyl ammonium chloride, benzyldimethyltetradecyl ammonium chloride, benzyldodecyldimethyl ammonium bromide, benzyldodecyldimethyl ammonium chloride, cetylpyridinium chloride, choline p-toluenesulfonate, dimethyldi(octadecyl)ammonium bromide, dodecylethyldimethylammonium bromide, dodecyltrimethylammonium chloride (DTAC), ethylhexadecyldimethylammonium bromide, dodecyl(2-hydroxyethyl)dimethylammonium bromide, hexadecyl(2-hydroxyethyl)dimethylammonium chloride, cetyltrimethylammonium p-toluenesulfonate, dodecylpyridinium chloride (laurylpyridinium chloride), dodecyltrimethylammonium methanesulfonate, dodecyltrimethylammonium p-toluenesulfonate, [9-(2-carboxyphenyl)-6-diethylamino-3-xanthenyl]-diethylammonium chloride (Rhodamine B) Girard's reagent reagent), hexadecyl (2-hydroxyethyl) dimethyl ammonium dihydrogen phosphate, hexadecyl pyridinium bromide, hexadecyl trimethyl ammonium bromide, hexadecyl trimethyl ammonium chloride, methyl benzethonium chloride,. 1622、Luviquatw M, N,N',N'-polyoxyethylene (10)-N-tallow-1,3-diaminopropane liquid, oxyphenonium bromide, tetraheptyl ammonium bromide, tetra(decyl)ammonium bromide, thonzonium bromide, tri(dodecyl)ammonium chloride, trimethyloctadecyl ammonium bromide, 1-methyl-3-n-octyl imidazolium tetrafluoroborate, 1-decyl-3-methyl imidazolium tetrafluoroborate, 1-decyl-3-methyl imidazolium chloride, tri(dodecyl)methyl ammonium bromide, dimethyl distearyl ammonium chloride and hexahydroxyquaternary ammonium chloride. Other corrosion inhibitors include nonionic surfactants such as PolyFox PF-159 (OMNOVA Solutions), poly(ethylene glycol) ("PEG"), poly(propylene glycol) ("PPG"), PEG-PPG copolymers such as Pluronic F-127 (BASF), anionic surfactants such as dodecylbenzene sulfonic acid, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, and combinations thereof. Quaternary salts can act as both corrosion inhibitors (especially for copper and tungsten) and wetting agents. Preferred tungsten corrosion inhibitors include Ether amines, including but not limited to: ether quaternary amines (e.g., Q series, such as isodecyloxypropyl bis-(2-hydroxyethyl) methyl ammonium chloride, isotridecyloxypropyl bis-(2-hydroxyethyl) methyl ammonium chloride, monosoy methyl ammonium chloride, tallow diamine diquaternary ammonium salt, coconut oil poly (15) oxyethylene methyl ammonium chloride), oxide ether amines (e.g., AO series, such as bis-(2-hydroxyethyl) isodecyloxypropyl amine oxide, linear alkoxypropyl amine oxide, low foam alkoxypropyl amine oxide (AO-405 and AO-455)), and combinations thereof. Other amine oxide surfactants will also be suitable tungsten corrosion inhibitors, including but not limited to: dodecyl dimethyl amine oxide, bis-(2-hydroxyethyl) coconut alkyl amine oxide ( C / 12W, Akzo Nobel), dimethyl coconut alkyl amine oxide ( DMC), 4-(benzyloxy)pyridine N-oxide, 4-(3-phenylpropyl)pyridine N-oxide, and combinations thereof. Other suitable tungsten corrosion inhibitors include heterocyclics (such as pyridine, quinoline, quinazoline, isoquinoline, pyrazine, pyrimidine, pyridazine, quinoxaline, phenazine, phenanthridine, 2,2'-pyridine, 1,4'-pyridine, 4,4'-pyridine and acridine), and C 1-6Derivatives of said heterocycles of at least one of alkyl, phenyl, benzyl, phenethyl, 3-phenylpropyl, benzyloxy, carboxyl, chloro, bromo, methoxy, nitro and cyano, including but not limited to 2-benzylpyridine and 4-(4-nitrobenzyl)pyridine. It will be apparent to those skilled in the art that although quaternary salts are most commonly available as chlorides or bromides, they are readily ion exchanged with halide anions using non-halide anions such as sulfate, methanesulfonate, nitrate, hydroxide, etc. The converted quaternary salts are also contemplated and preferred herein. In one embodiment, the corrosion inhibitor comprises a cationic quaternary salt, more preferably myristyltrimethylammonium bromide, benzalkonium chloride, cetyltrimethylammonium p-toluenesulfonate, DTAC and cetyltrimethylammonium hydroxide, wherein the chloride has been ion exchanged prior to use.

[0032] In one embodiment, the corrosion inhibitor is selected from the group consisting of benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, 4-(3-phenylpropyl)pyridine, and 5-methyl-benzotriazole.

[0033] The present composition may include one or more compounds (i.e., pH adjusting agents) capable of regulating (i.e., adjusting) the pH of the composition. The pH of the composition can be regulated using any suitable compound capable of regulating the pH of the composition. The pH adjusting agent is preferably water-soluble and compatible with the other components of the composition. Typically, the composition has a pH of about -1 to 5, or 0 to 4, or 2 to 4 at the point of use. Non-limiting examples of pH adjusting agents include inorganic acids and organic acids, including methanesulfonic acid, ethanesulfonic acid, phosphoric acid, sulfuric acid, hydrogen chloride, etc.

[0034] The at least one solvent may comprise water, at least one water-miscible organic solvent, or a combination thereof, wherein the at least one water-miscible organic solvent is selected from the group consisting of: 1 R 2 R 3 C(OH) compounds, wherein R 1 , R 2 and R 3 are independent of each other and are selected from the group consisting of: hydrogen, C 2 -C 30 Alkyl, C 2 -C 30 Olefins, cycloalkyls, C 2 -C 30Alkoxy and combinations thereof. For example, the at least one solvent may include at least one species selected from the group consisting of water, methanol, ethanol, isopropanol, butanol and higher alcohols, tetrahydrofurfuryl alcohol (THFA), 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 (THF), N-methylpyrrolidone (NMP), cyclohexylpyrrolidone, N-octylpyrrolidone, N-phenylpyrrolidone, methyldiethanolamine, methyl formate, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetramethylene sulfone (cyclopentane), ether, phenoxy-2-propanol (PPh), ethyl phenyl ketone (propriophenone), ethyl lactate, acetic acid Ethyl ester, ethyl benzoate, acetonitrile, acetone, ethylene glycol, propylene glycol (PG), 1,3-propylene glycol, 1,4-propylene 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 (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), dibasic ester, glycerol carbonate, N-formyl morpholine, triethyl phosphate and combination thereof. In one embodiment, at least one solvent comprises water, for example deionized water. In one embodiment, the solvent miscible with water is selected from ethylene glycol and propylene glycol.

[0035] Optionally, the composition may contain at least one complexing agent / chelating agent. However, when the oxidizing agent is a peroxy compound (such as hydrogen peroxide), the complexing agent is an essential component of the composition. The complexing agent (if present) is added to reduce particle generation and growth and improve the shelf life of the composition. Complexing agents contemplated include, but are not limited to, β-diketone compounds such as 2,4-pentanedione, acetylacetonate, 1,1,1-trifluoro-2,4-pentanedione, and 1,1,1,5,5,5-hexafluoro-2,4-pentanedione; amino acids such as glycine, serine, proline, leucine, alanine, asparagine, aspartic acid, glutamine, histidine, glutamic acid, arginine, cysteine, valine, and lysine; polyprotic acids and aminopolycarboxylic acids selected from the group consisting of iminodiacetic acid (IDA), malonic acid, oxalic acid, succinic acid, boric acid, nitrilotriacetic acid, malic acid, citric acid, acetic acid, maleic acid, ethylenediaminetetraacetic acid (EDTA), ethylenediaminetetraacetic acid diammonium salt (EDTA-2NH 3 ), (1,2-cyclohexylenediazolyl)tetraacetic acid (CDTA), diethylenetriaminepentaacetic acid (DTPA), 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA), ethylenediaminedisuccinic acid and propylenediaminetetraacetic acid; phosphonic acid; phosphonic acid derivatives, such as hydroxyethylidenediphosphonic acid (HEDP) (Dequest 2010), 1-hydroxyethane-1,1-diphosphonic acid, nitrogen-tris(methylenephosphonic acid) (NTMP), aminotris(methylenephosphonic acid) (Dequest 2000), diethylenetriaminepenta(methylenephosphonic acid) (Dequest 2060S), ethylenediaminetetra(methylenephosphonic acid) (EDTMPA); and combinations thereof. Alternatively or in addition, the at least one complexing agent may include an anionic surfactant, which includes, but is not limited to, sodium alkyl sulfates (such as sodium ethylhexyl sulfate ( 08)), alkyl ammonium sulfate, alkyl (C 10 -C 18 ) carboxylic acid ammonium salt, sodium sulfosuccinate and its esters (e.g. sodium sulfosuccinate dioctyl ester), alkyl (C 6 -C 18 ) sulfonate sodium salt and di-anionic sulfonate surfactant. Preferred anionic surfactants include oxidized diphenyl disulfonate, such as the DOWFAX series of anionic surfactants available from Dow Chemical, which include DOWFAX 2A1 (sodium oxidized tetrapropyl diphenyl disulfonate), DOWFAX 3A2, DOWFAX 8390 and DowFax TMC6L (oxyalkylene diphenyl disulfonate), and RHODACAL DSB from Rhone-Poulenc, POLY-TERGENT 2A1, POLY-TERGENT 2EP from Olin, AEROSOL DPOS-45 from Cytec, CALFAX DBA-40, CALFAX 16L-35 from Pilot Chemicals, etc. Oxyalkylene disulfonate surfactants represent a class of highly anionic surfactants consisting of disulfonated oxyalkylene diphenyl molecules in which the charge is generated by two sulfonate groups and provide excellent emulsion stability. Alternatively or additionally, at least one complexing agent may include a scale inhibitor polymer including, but not limited to, polyaminoamide (PAMAM) dendrimers, poly(2-ethyl-2-oxazoline), polyethyleneimine (PEI), hydroxylated polyethyleneimine, modified polyethyleneimine, polyallylamine hydrochloride (PALAM), poly(acrylamide), poly(acrylic acid), poly(diallyldimethylammonium chloride), diallyldimethylammonium chloride, acrylamide, acetoguanamine, poly(acrylamide-co-diallyldimethylammonium chloride) (PAMALAM), and combinations thereof. Alternatively or additionally, the complexing agent includes a salt comprising an ammonium cation or a tetraalkylammonium cation ([NR 1 R 2 R 3 R 4 ] + , where R 1 , R 2 , R 3 and R 4 may be the same as or different from each other and are selected from hydrogen and C 1 -C 6 The salt may include ammonium bromide and / or ammonium chloride. In one embodiment, the complexing agent includes at least one of an oxyalkylene diphenyl disulfonate, 2,4-pentanedione, serine, and any combination thereof.

[0036] In another embodiment, any of the compositions of the present invention may further comprise titanium nitride and / or photoresist etch material residues, wherein the residues are suspended and / or dissolved in the aqueous composition.

[0037] In one embodiment, the composition of the first aspect comprises, consists of, or consists essentially of at least one oxidizing agent, at least one fluoride-containing etchant, at least one pH adjuster, at least one metal corrosion inhibitor, and optionally at least one water-miscible solvent, wherein components a to f (if present) are present in the following ratios:

[0038] a. 50 to (balance of material) weight percent (water);

[0039] b. 0.001 to 5 weight percent (oxidant);

[0040] c. 0.001 to 5 weight percent (fluoride etchant);

[0041] d. 0.001 to 5 weight percent (metal corrosion inhibitor);

[0042] e. 0.1 to 10 weight percent (pH adjuster); and optionally

[0043] f. 1 to 30 weight percent (water-miscible solvent).

[0044] In another aspect, the present invention provides a composition comprising:

[0045] a.water;

[0046] b. at least one oxidizing agent selected from periodic acid; hydrogen peroxide, hydrogen peroxide-urea, ammonium persulfate, peracetic acid, tert-butyl hydroperoxide and potassium permanganate;

[0047] c. at least one etchant selected from HF, tetrafluoroboric acid, hexafluorosilicic acid, H 2 ZF 6 , H 2 TiF 6 , HPF 6 , ammonium fluoride, tetramethylammonium fluoride, tetramethylammonium hydroxide, ammonium hexafluorosilicate and ammonium hexafluorotitanate;

[0048] d. at least one metal corrosion inhibitor selected from the group consisting of benzyldimethyloctylammonium chloride, benzyldimethyldodecylammonium chloride, benzyldimethyltetradecylammonium chloride, benzyldimethyloctadecylammonium chloride, 4-(3-phenylpropyl)pyridine, 4-(3-phenylpropyl)pyridine n-oxide, 3-benzylpyridine N-oxide, benzotriazole, 5-methylbenzotriazole, tolyltriazole, 1,2,4-triazole, and combinations thereof;

[0049] e. at least one pH adjusting agent selected from methanesulfonic acid, sulfuric acid, hydrochloric acid, nitric acid, acetic acid and phosphoric acid; and optionally

[0050] f. at least one water-miscible solvent.

[0051] Certain compositions suitable for etching or removing titanium nitride utilize passivating agents, which are used to reduce chemical attack on the low-k dielectric layer and protect the wafer from additional oxidation. (See, for example, U.S. Patent No. 10,138,117, which is incorporated herein by reference.) Among such compositions are low-k passivating agents, such as boric acid, borates, alkoxysilanes, sodium silicate, tetramethylammonium silicate, 3-hydroxy-2-naphthoic acid, malonic acid, and iminodiacetic acid. It has been found that the compositions of the present invention do not require such passivating agents to effectively and selectively remove titanium nitride. Therefore, in another embodiment, the compositions of the present invention do not contain a low-k passivating agent.

[0052] It will be appreciated that it is customary to prepare a concentrated form of the composition to be diluted prior to use. For example, the composition may be made in a more concentrated form and thereafter diluted with at least one solvent at the manufacturer, prior to use, and / or during factory use. The dilution ratio may range from about 0.1 part diluent: 1 part composition concentrate to about 100 parts diluent: 1 part composition concentrate. It will be further appreciated that the compositions described herein include an oxidant that may be unstable over time. Thus, the concentrated form may be substantially free of an oxidant, and the oxidant may be introduced by the manufacturer into the concentrate or diluted composition prior to use and / or during factory use.

[0053] By simply adding the corresponding ingredients and mixing to a homogeneous condition, it is easy to formulate the compositions described herein. In addition, the composition can be easily formulated as a single package formulation or a multi-part formulation that is mixed at the time of use or before, preferably a multi-part formulation. The individual parts of the multi-part formulation can be mixed in a tool or in a mixing zone / domain (such as an inline mixer or in a storage tank upstream of the tool). It is contemplated that the parts of the multi-part formulation can contain any combination of ingredients / components that form the desired composition when mixed together. The concentration of the corresponding ingredients can vary widely with a specific multiple of the composition, i.e., more dilute or more concentrated, and it should be understood that the composition can be variously and alternatively comprised of any combination of ingredients consistent with the disclosure herein, composed of any combination of ingredients consistent with the disclosure herein, or substantially composed of any combination of ingredients consistent with the disclosure herein.

[0054] Therefore, in another aspect, the present invention provides a kit comprising, in one or more containers, one or more components suitable for forming the compositions described herein. The containers of the kit must be suitable for storing and transporting the removal composition components, e.g. Containers (Advanced Technology Materials, Danbury, Conn., USA). The one or more containers containing the components of the composition preferably include means for placing the components in the one or more containers in fluid communication for blending and dispensing. For example, reference Containers, gas pressure can be applied to the exterior of the liner in the one or more containers to cause at least a portion of the contents of the liner to be expelled 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 composition to a processing tool.

[0055] Substantially chemically inert, impurity-free, flexible and elastic polymeric film materials (such as high density polyethylene) can be used to make the liner of the one or more containers. The liner that is suitable for processing does not require a co-extruded layer or a barrier layer, and does not require any pigments, UV inhibitors or treatment agents that may adversely affect the purity requirements of the components to be placed in the liner. A list of ideal liners includes films comprising virgin (i.e., additive-free) polyethylene, virgin polytetrafluoroethylene (PTFE), polypropylene, polyurethane, polyvinylidene chloride, polyvinyl chloride, polyacetal, polystyrene, polyacrylonitrile, polybutylene, etc. The preferred thickness of such liners is in the range of about 5 mils (0.005 inches) to about 30 mils (0.030 inches), for example, a thickness of 20 mils (0.020 inches).

[0056] With respect to containers for use in the kits, the disclosures of the following patents and patent applications are hereby incorporated by reference in their respective entireties: U.S. Patent No. 7,188,644, entitled "APPARATUS AND METHOD FOR MINIMIZING THE GENERATION OF PARTICLES IN ULTRAPURE LIQUIDS"; U.S. Patent No. 6,698,619, entitled "RETURNABLE AND REUSABLE, BAG-IN-DRUM FLUID STORAGE AND DISPENSING CONTAINER SYSTEM"; and PCT / US08 / 63276, filed May 9, 2008, entitled "SYSTEMS AND METHODS FOR MATERIAL BLENDING AND DISTRIBUTION", each of which is hereby incorporated by reference.

[0057] In another aspect, the present invention provides a method of etching titanium nitride material from the surface of a microelectronic device having titanium nitride material thereon using the compositions described herein. For example, the titanium nitride material can be removed without substantially destroying / removing metal conductors and insulator materials present on the microelectronic device. Thus, in another embodiment, a method is described for selectively and substantially removing titanium nitride from the surface of a microelectronic device having titanium nitride thereon using the compositions described herein relative to molybdenum, aluminum oxide, silicon dioxide, polysilicon. In another embodiment, a method is described for selectively and substantially removing titanium nitride from the surface of a microelectronic device having titanium nitride thereon using the compositions described herein relative to metal conductors (e.g., copper), tungsten, and insulator materials.

[0058] In etching applications, the composition is applied to the surface of a microelectronic device having titanium nitride and / or photoresist etch residue material thereon in any suitable manner, for example, by spraying the composition onto the surface of the device; by immersing (in a static or dynamic volume of the composition) a device comprising titanium nitride; by contacting the device with another material having the composition absorbed thereon (e.g., a pad or fibrous sorbent applicator element); by contacting the device comprising titanium nitride and / or photoresist etch residue material with a circulating composition; or by any other suitable means, manner, or technique, the composition is brought into contact with the titanium nitride film for removal. Coating may be performed in batch or single wafer equipment for dynamic or static cleaning. Advantageously, the compositions described herein achieve at least partial removal of titanium nitride in an efficient and highly selective manner by virtue of their selectivity for titanium nitride films relative to other materials that may be present on the microelectronic device structure and exposed to the composition, such as metals and insulating materials (i.e., low-k dielectrics) and high-k materials (e.g., hafnium oxide, zirconium oxide, titanium oxide).

[0059] When using the compositions described herein to remove titanium nitride from a microelectronic device structure having titanium nitride thereon, the composition is typically contacted with the device structure in a single wafer tool for a sufficient time of about 0.3 minutes to about 30 minutes or about 0.5 minutes to about 3 minutes at a temperature in the range of about 20° C. to about 100° C. or about 30° C. to about 60° C. Such contact times and temperatures are illustrative, and any other suitable time and temperature conditions that are effective to at least partially remove the titanium nitride film from the device structure may be employed.

[0060] After achieving the desired etching / removal effect, the composition can be easily removed from the microelectronic device to which it was previously applied, such as by rinsing, washing or other removal steps, as may be desired and effective in a given end-use application of the composition described herein. For example, the device can be rinsed with a rinse solution including deionized water and / or dehydrated (e.g., centrifugal dehydration, N 2 , steam dehydration, etc.). Thus, in another aspect, the present invention provides a method for selectively etching titanium nitride on a microelectronic device in the presence of molybdenum, comprising exposing the microelectronic device to a composition of the present invention at a temperature of about 20°C to about 70°C for a period of about 30 seconds to about 10 minutes, followed by washing the microelectronic device with deionized water.

[0061] In another aspect, the present invention provides improved microelectronic devices made according to the methods described herein and products containing such microelectronic devices.

[0062] In another aspect, the present invention provides a method of making an article comprising a microelectronic device, the method comprising contacting the microelectronic device with a composition for a sufficient time to etch away titanium nitride from a surface of the microelectronic device having titanium nitride thereon, and incorporating the microelectronic device into the article, wherein the composition comprises, consists of, or consists essentially of at least one oxidizing agent, at least one etchant, at least one corrosion inhibitor, optionally at least one complexing agent, and optionally at least one water-miscible solvent.

[0063] Certain specific microelectronic devices involving gate etching in 3D NAND flash memory structures involve a first step of making a molybdenum recess with a high selectivity etchant via a dry etching process as described above. In a second step, the methods and compositions of the present invention are implemented to selectively etch titanium. Therefore, in another aspect, the present invention provides a method for selectively etching molybdenum and titanium nitride in sequential steps, comprising:

[0064] a. Etch molybdenum using dry etching method, then

[0065] b. Selectively etching titanium nitride on a microelectronic device in the presence of molybdenum, comprising exposing the microelectronic device to a composition according to the present invention at a temperature of about 20° C. to about 70° C. for a period of about 30 seconds to about 10 minutes, followed by washing the microelectronic device with deionized water.

[0066] In another aspect, the present invention provides an article comprising, consisting of, or consisting essentially of: a microelectronic device substrate, a titanium nitride layer on the substrate, and a composition as described herein. In one embodiment, the present invention provides a composition consisting of or consisting essentially of components a. to f. listed above.

[0067] The present invention can be further illustrated by the following examples of preferred embodiments thereof, but it should be understood that these examples are included for illustrative purposes only and are not intended to limit the scope of the present invention unless specifically indicated otherwise.

[0068] Examples

[0069] symbol:

[0070] MSA: Methanesulfonic acid

[0071] 12C: Benzyldimethyldodecylammonium chloride

[0072] 14C: Benzyldimethyltetradecylammonium chloride

[0073] PPP: 4-(3-phenylpropyl)pyridine

[0074] DIW: Deionized water

[0075] 5m-BTA: 5-methylbenzotriazole

[0076] RPM - refers to the revolutions per minute of the magnetic stir bar used in the experiment.

[0077] 1. Oxidant test (periodic acid)

[0078] 1) Formulation and test conditions

[0079]

[0080] 2) Etching results:

[0081]

[0082] In these experiments, it was noted that the higher the periodic acid concentration, the higher the Mo etch rate. In addition, the higher the periodic acid concentration, the lower the TiN etch rate. Therefore, in order to improve the TiN / Mo selectivity, it is advisable to reduce the periodic acid concentration. If the formulation does not have periodic acid, the TiN etch rate is very low.

[0083] 2. Other oxidant tests (periodic acid vs. hydrogen peroxide)

[0084] 1) Formulation and test conditions

[0085]

[0086]

[0087] 2) Etching rate results

[0088]

[0089] It can be observed that when hydrogen peroxide is used as the oxidant, the Mo etch rate increases significantly with concentration.

[0090] 3. HF analysis test (etchant)

[0091] 1) Formulation and test conditions

[0092]

[0093] 2) Test results:

[0094]

[0095] In these experiments, it was noted that the higher the HF concentration, the higher the TiN and Mo etch rates. The TEOS etch rate also increased at higher HF concentrations, but not to an excessive degree. The formulation without HF had a very low TiN etch rate.

[0096] 4.C12 concentration analysis test (Mo inhibitor)

[0097] 1) Formulation and test conditions:

[0098]

[0099]

[0100] 2) Etching rate results:

[0101]

[0102] In these experiments, it was noted that 12C (benzyldimethyldodecylammonium chloride) was effective as a Mo inhibitor. Additionally, the higher the 12C concentration, the lower the molybdenum etch rate. The higher the 12C concentration, the lower the titanium nitride etch rate. Finally, the 12C concentration did not seem to affect the etch rates of other materials such as AlOx, TEOS, and poly-Si.

[0103] 5. Other Mo inhibitor tests (12C, 14C, 5m-BTA, PPP, glycine)

[0104] 1) Formulation and test conditions

[0105]

[0106] 2) Test results:

[0107]

[0108] In these experiments, it is noted that 12C exhibits a higher TiN / Mo selectivity than 14C (benzyldimethyltetradecylammonium chloride). In addition, when the 12C concentration increases, both Mo and TiN etch rates decrease. Each of 12C, PPP (4-(3-phenylpropyl)pyridine), and 5m-BTA (5-methyl-benzotriazole) acts as a Mo inhibitor, which helps to improve the TiN / Mo selectivity. Finally, the inhibitor combination formulation can help reduce the Mo etch rate. When comparing compositions 15 to 17, composition 17 has the lowest Mo etch rate, which produces the highest TiN / Mo selectivity.

[0109] 6. pH adjuster test

[0110] 1) Formulation and test conditions

[0111]

[0112] 2) Etching rate results:

[0113]

[0114] Observations:

[0115] (1) The formulations containing pH adjusters have similar TiN / Mo selectivities.

[0116] (2) The formulation without pH adjuster has a lower Mo etch rate, which results in a higher TiN / Mo selectivity, but has the disadvantage of showing a higher TEOS Mo etch rate.

[0117] 7.Solvent test

[0118] 1) Formulation and test conditions:

[0119]

[0120] 2) Etching rate results:

[0121]

[0122] Observations:

[0123] (1) Ethylene glycol helps dissolve 5m-BTA in the formulation.

[0124] (2) However, the formulation containing EG has a lower TiN / Mo selectivity.

[0125] The invention has been described in detail with particular reference to certain embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.

Claims

1. A composition comprising: a.water; b. 0.001 to 5 weight percent of at least one oxidizing agent; c. at least one fluoride-containing etchant; d. at least one platinum corrosion inhibitor, wherein the at least one platinum corrosion inhibitor comprises 4-(3-phenylpropyl)pyridine and 5-methylbenzotriazole; e. at least one pH adjusting agent; The pH of the composition is between -1 and 5.

2. The composition according to claim 1, wherein the pH is 0 to 4.

3. The composition of claim 1, wherein the fluoride-containing etchant is selected from HF, tetrafluoroboric acid, hexafluorosilicic acid, H2ZrF6, H2TiF6, HPF6, ammonium fluoride, tetramethylammonium fluoride, ammonium hexafluorosilicate, ammonium hexafluorotitanate, or a combination thereof. The composition of claim 1 , wherein the fluoride-containing etchant is HF.

5. The composition of claim 1, wherein the composition comprises a water-miscible solvent selected from ethylene glycol and propylene glycol.

6. The composition of claim 1, wherein the oxidizing agent is periodic acid, the etchant is HF, and wherein the molybdenum corrosion inhibitor further comprises dodecyltrimethylammonium chloride or benzyldimethyltetradecylammonium chloride.

7. A method for selectively etching titanium nitride on a microelectronic device in the presence of molybdenum comprising exposing the microelectronic device to the composition of claim 1 at a temperature of 20°C to 70°C for a period of 30 seconds to 10 minutes, followed by washing the microelectronic device with deionized water.

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