SOLVENT-BASED COMPOSITIONS AND RELATED METHODS FOR MOLYBDENUM ETCHING

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 USC 119 of U.S. Provisional Patent Application No. 63/640,401, filed Apr. 30, 2024, the disclosure of which is hereby incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to solvent-based molybdenum etching compositions and related methods.

BACKGROUND

Few solvents are compatible with nitric acid in PAN (phosphoric acid, acetic acid, and nitric acid mixture)-based formulations. Conventional PAN use a high ratio of acetic acid in the formulation, resulting in a low flash point.

SUMMARY

Some embodiments relate to solvent-based molybdenum etching compositions and related methods. In some embodiments, a composition for etching molybdenum comprises a phosphorus oxoacid, an oxidant, and at least 50% by weight of a solvent based on a total weight of the composition. In some embodiments, the solvent comprises a compound having at least one sulfur-oxygen double bond.

Some embodiments relate to a composition. In some embodiments, the composition comprises a phosphorus oxoacid, an oxidant, and a solvent. In some embodiments, the solvent comprises a compound having at least one sulfur-oxygen double bond. In some embodiments, the composition when tested according to American Society for Testing and Materials (ASTM) D93-20: Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, has a flash point of at least 100° C.

Some embodiments relate to a method. In some embodiments, the method comprises one or more of the following steps: obtaining a structure comprising a plurality of recesses, and a molybdenum material located in the plurality of recesses; and contacting the structure with a composition to remove at least a portion of the molybdenum material. In some embodiments, the composition comprises a phosphorus oxoacid, an oxidant, and at least 50% by weight of a solvent based on a total weight of the composition. In some embodiments, the solvent comprises a compound having at least one sulfur-oxygen double bond.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart of a method for the removal of molybdenum, where a 3D NAND structure with molybdenum is subjected to a wet etch composition, according to some embodiments.

FIG. 2 is an illustration of the results of a method for the removal of molybdenum, where a 3D NAND structure with molybdenum is subjected to a solvent-based composition, according to some embodiments.

DETAILED DESCRIPTION

Among those benefits and improvements that have been disclosed, other objects and advantages of this disclosure will become apparent from the following description taken in conjunction with the accompanying figures. Detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely illustrative of the disclosure that may be embodied in various forms. In addition, each of the examples given regarding the various embodiments of the disclosure which are intended to be illustrative, and not restrictive.

Any prior patents and publications referenced herein are incorporated by reference in their entireties.

Throughout the specification and claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise. The phrases “in one embodiment,” “in an embodiment,” and “in some embodiments” as used herein do not necessarily refer to the same embodiment(s), though it may. Furthermore, the phrases “in another embodiment” and “in some other embodiments” as used herein do not necessarily refer to a different embodiment, although it may. All embodiments of the disclosure are intended to be combinable without departing from the scope or spirit of the disclosure.

As used herein, the term “based on” is not exclusive and allows for being based on additional factors not described, unless the context clearly dictates otherwise. In addition, throughout the specification, the meaning of “a,” “an,” and “the” include plural references. The meaning of “in” includes “in” and “on.”

Some embodiments relate to solvent-based compositions and related methods for molybdenum etching from a microelectronic device, such as, for example and without limitation, a 3D NAND structure. The solvent-based composition may comprise a higher flash point compared to the flash point of a conventional PAN composition (phosphoric acid, acetic acid, and nitric acid) during molybdenum etching. In some embodiments, the composition may achieve improved etching uniformity compared to etching uniformity using conventional PAN composition.

The composition for etching molybdenum may comprise a phosphorus oxoacid. Phosphorus oxoacid may comprise acids. The acids may comprise a phosphorus and an oxygen. In some embodiments, phosphorus oxoacid may comprise phosphorus and oxygen in different proportions. In some embodiments, for example, the phosphorus oxoacid comprises at least one of Hypophosphoric acid, Metaphosphoric acid, Pyrophosphoric acid, Hypophosphorous acid, Phosphorous acid, Peroxophosphoric acid, Orthophosphoric acid, or any combination thereof.

Phosphorus oxoacid may comprise at least one of Phosphoric acid, Pyrophosphoric acid, Etidronic acid, Triphosphoric acid, Hypophosphorous acid, Phosphorous acid, Tetrapolyphosphoric acid, Trimetaphosphoric acid, phosphoric anhydride, Phenylphosphonic Acid, n-Octylphosphonic acid, n-Octadecylphosphonic acid, Decylphosphonic acid, Benzylphosphonic acid, 2-Phosphonobutane-1,2,4-tricarboxylic acid, Polyphosphoric acid, Tris(2-ethylhexyl) phosphate, Diphenyl hydrogen phosphate, 2-Ethylhexyl diphenyl phosphate, Hexadecyl dihydrogen phosphate, Bis(2-ethylhexyl) phosphate, 2-ethylhexyl dihydrogen phosphate, Trimethyl phosphate, Diethyl phosphate, Triethyl phosphate, Tripropyl phosphate, Dibutyl phosphate, Tributyl phosphate, Trioctyl phosphate, Triisobutyl phosphate, Tris(2-isopropylphenyl) Phosphate, Triphenyl phosphate, Diphenyl methyl phosphate, Tricresyl phosphate, Trioctylphosphine oxide, Triethyl phosphate, Tri-n-butyl phosphate, Pyridoxal phosphate, Glycerophosphoric acid, [(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl) oxan-2-yl] dihydrogen phosphate, Tris(2,3-dichloropropyl) phosphate, Tris(2-butoxyethyl) phosphate, Tris(2-chloroethyl)phosphate, O-Phospho-L-serine, Fructose-1,6-Bisphosphate, Fructose 6-phosphate, Phenyl dihydrogen phosphate, methyl phosphate, Diphenyl phosphate, Tetrabenzyl Pyrophosphate, O-Phosphorylethanolamine, Aminopropyl dihydrogen phosphate, Aminopropyl dihydrogen phosphate, 2-Ethylhexyl diphenyl phosphate, Dibenzyl phosphate, Dibenzyl phosphate, Amphisol A, Tris(4-nitrophenyl)phosphate, (1-Oxido-2,6,7-trioxa-1-phosphabicyclo [2.2.2] oct-4-yl) methanol, Tris(trimethylsilyl) phosphate, Tris(1-chloro-2-propanyl) phosphate, methyl (4-nitrophenyl) hydrogen phosphate, Alkyl diphenyl phosphate, Choline glycerophosphate, 4-Aminophenylphosphorylcholine, di-tert-butyl(chloromethyl) phosphate, (2S)-2-amino-3-(phosphonooxy) propanoic acid, diethoxyphosphinic acid, dimethoxyphosphinic acid, diphenoxyphosphinic acid, (2-aminoethoxy) phosphonic acid, bis(benzyloxy) phosphinic acid, bis(octyloxy) phosphinic acid, 2-(phosphonooxy)benzoic acid, [2-(N-methylcarbamimidamido) ethoxy] phosphonic acid, 2-(phosphonooxy) acetic acid, (2S)-2-amino-3-[4-(phosphonooxy)phenyl] propanoic acid, 4-hydroxyphenyl diphenyl phosphate, {2-[(2-amino-6-oxo-6,9-dihydro-1H-purin-9-yl) methoxy]ethoxy} phosphonic acid, (2R)-2-amino-3-(phosphonooxy) propanoic acid, diethyl 4-oxo-3,4-dihydro-1,2,3-benzotriazin-3-yl phosphate, {[(2R,3S)-2,3-dihydroxy-4-oxopentyl]oxy} phosphonic acid, di-tert-butyl chloromethyl phosphate, [(2R)-2,3-dihydroxypropoxy] [2-(trimethylazaniumyl) ethoxy] phosphinic acid and combinations thereof. Preferably, the etchant comprises Phosphoric acid, Pyrophosphoric acid, polyphosphoric acid, or combinations thereof.

The composition for etching molybdenum may comprise 1% to 30% by weight of the phosphorus oxoacid based on the total weight of the composition, or any range or subrange between 1% to 30%. For example, in some embodiments, the percent by weight of phosphorus oxoacid based on the total weight of the composition may be 1% to 15%, 1% to 10%, or 5% to 30%. In some embodiments, the percent by weight of phosphorus oxoacid based on the total weight of the composition may be 2% to 30%, 3% to 30%, 4% to 30%, 5% to 30%, 6% to 30%, 7% to 30%, 8% to 30%, 9% to 30%, 10% to 30%, 11% to 30%, 12% to 30%, 13% to 30%, 14% to 30%, 15% to 30%, 16% to 30%, 17% to 30%, 18% to 30%, 19% to 30%, 20% to 30%, or 20% to 25%. In some embodiments, the percent by weight of phosphorus oxoacid based on the total weight of the composition may be 1% to 19%, 1% to 18%, 1% to 17%, 1% to 16%, 1% to 15%, 1% to 14%, 1% to 13%, 1% to 12%, 1% to 11%, 1% to 10%, 1% to 9%, 1% to 8%, 1% to 7%, 1% to 6%, 1% to 5%, 1% to 4%, 1% to 3%, or 1% to 2%.

The composition for etching molybdenum may comprise an oxidant. The oxidant may oxidize the surface of a molybdenum material. In some embodiments, the oxidant is a strong oxidant. In some embodiments, the oxidant may be compatible with a solvent described herein.

The oxidant may comprise at least one of hydrogen peroxide (H₂O₂), FeCl₃, FeF₃, Fe(NO₃)³, Sr(NO₃)², CoF₃, MnF₃, oxone, (2KHSO₅·KHSO₄·K₂SO₄), nitric acid (HNO₃), ammonium peroxomonosulfate, ammonium chlorite (NH₄ClO₂), ammonium chlorate (NH₄ClO₃), ammonium iodate (NH₄IO₃), ammonium nitrate (NH₄NO₃), ammonium perborate (NH₄BO₃), ammonium perchlorate (NH₄ClO₄), ammonium periodate (NH₄IO₄), ammonium persulfate ((NH₄)2S₂O₈), ammonium hypochlorite (NH₄ClO), ammonium tungstate ((NH₄)10H₂ (W₂O₇)), sodium persulfate (Na₂S₂O₈), sodium hypochlorite (NaClO), sodium perborate, potassium iodate (KIO₃), potassium permanganate (KMnO₄), potassium persulfate (K₂S₂O₈), potassium hypochlorite (KClO), tetramethylammonium chlorite ((N(CH₃)₄)ClO₂), tetramethylammonium chlorate ((N(CH₃)₄) ClO₃), tetramethylammonium iodate ((N(CH₃)₄) IO₃), tetramethylammonium perborate ((N(CH₃)₄) BO₃), tetramethylammonium perchlorate ((N(CH₃)₄) ClO₄), tetramethylammonium periodate ((N(CH₃)₄) IO₄), tetramethylammonium persulfate ((N(CH₃)₄) S₂O₈), tetrabutylammonium peroxomonosulfate, peroxomonosulfuric acid, urea hydrogen peroxide ((CO(NH₂)₂) H₂O₂), peracetic acid (CH₃ (CO) OOH), t-butyl hydroperoxide, nitrobenzenesulfonate, 1,4-benzoquinone, toluquinone, dimethyl-1,4-benzoquinone, chloranil, alloxan, periodic acid, and combinations thereof. Preferably, the oxidant comprises nitric acid, ammonium persulfate, periodic acid, or combinations thereof.

In some embodiments, the composition comprises 0.1% to 20% by weight of the oxidant based on the total weight of the composition, or any range or subrange between 0.1% to 20%. For example, in some embodiments, the weight of the oxidant based on the total weight of the composition may be 0.1% to 15%, 0.1% to 10%, 0.1% to 5%, or 5% to 20%. In some embodiments, the weight of the nitric acid based on the total weight of the composition may be 0.5% to 20%, 1% to 20%, 1.5% to 20%, or 2% to 20%, 2.5% to 20%, 3% to 20%, 3.5% to 20%, 4% to 20%, 4.5% to 20%, 5% to 20%, 5.5% to 20%, 6% to 20%, 6.5% to 20%, 7% to 20%, 7.5% to 20%, 8% to 20%, 8.5% to 20%, 9% to 20%, 9.5% to 20%, 10% to 20%, 10.5% to 20%, 11% to 20%, 11.5% to 20%, 12% to 20%, 12.5% to 20%, 13% to 20%, 13.5% to 20%, 14% to 20%, 14.5% to 20%, 15% to 20%, 15.5% to 20%, 16% to 20%, 16.5% to 20%, 17% to 20%, 17.5% to 20%, 18% to 20%, 18.5% to 20%, 19% to 20%, or 19.5% to 20%. In some embodiments, the weight of the oxidant based on the total weight of the composition may be 0.1% to 19%, 0.1% to 18%, 0.1% to 17%, 0.1% to 16%, 0.1% to 15%, 0.1% to 14%, 0.1% to 13%, 0.1% to 12%, 0.1% to 11%, 0.1% to 10%, 0.1% to 9%, 0.1% to 8%, 0.1% to 7%, 0.1% to 6%, 0.1% to 5%, 0.1% to 4%, 0.1% to 3%, 0.1% to 2%, or 0.1% to 1%.

The composition for etching molybdenum may comprise at least 50% by weight of a solvent based on a total weight of the composition. The solvent may inhibit molybdenum etching. In some embodiments, the solvent may reduce metal-containing residues on molybdenum slits. In some embodiments, the solvent may reduce the generation of metal-containing residues on molybdenum slits. In some embodiments, the solvents may increase the flash point of the composition. In some embodiments, the solvent when combined with other composition components, for example, an oxidant, an phosphorus oxoacid, an inhibitor, and a stabilizer, may maintain a low top-to-bottom recess depth difference in a 3D NAND structure. The solvent may comprise a compound having at least one sulfur-oxygen double bond. In some embodiments, the solvent may be compatible with a strong oxidant.

For example, in some embodiments, the weight of a solvent based on a total weight of the composition may be at least 55%, at least 60%, at least 65%, at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 99%. In some embodiments, the weight of a solvent based on a total weight of the composition may be at least 50% to 99%, at least 55% to 99%, at least 60% to 99%, at least 65% to 99%, at least 70% to 99%, at least 75% to 99%, at least 80% to 99%, at least 85% to 99%, at least 90% to 99%, or at least 95% to 99%. In some embodiments, the weight of a solvent based on a total weight of the composition may be at least 50% to 95%, at least 50% to 90%, at least 50% to 85%, at least 50% to 80%, at least 50% to 75%, at least 50% to 70%, at least 50% to 65%, at least 50% to 60%, or at least 50% to 55%.

In some embodiments, the composition comprises 50% to 95% by weight of the solvent based on the total weight of the composition, or any range or subrange between 50% to 95%. For example, in some embodiments, the weight of the solvent based on the total weight of the composition may be 55% to 90%, 60% to 85%, 65% to 80%, or 70% to 75%. In some embodiments, the weight of the solvent based on the total weight of the composition may be 51% to 95%, 52% to 95%, 53% to 95%, 54% to 95%, 55% to 95%, 56% to 95%, 57% to 95%, 58% to 95%, 59% to 95%, 60% to 95%, 61% to 95%, 62% to 95%, 63% to 95%, 64% to 95%, 65% to 95%, 66% to 95%, 67% to 95%, 68% to 95%, 69% to 95%, 70% to 95%, 71% to 95%, 72% to 95%, 73% to 95%, 74% to 95%, 75% to 95%, 76% to 95%, 77% to 95%, 78% to 95%, 79% to 95%, 80% to 95%, 81% to 95%, 82% to 95%, 83% to 95%, 84% to 95%, 85% to 95%, 86% to 95%, 87% to 95%, 88% to 95%, 89% to 95%, 90% to 95%, 91% to 95%, 92% to 95%, 93% to 95%, 94% to 95%. In some embodiments, the weight of the solvent based on the total weight of the composition may be 50% to 94%, 50% to 93%, 50% to 92%, 50% to 91%, 50% to 90%, 50% to 89%, 50% to 88%, 50% to 87%, 50% to 86%, 50% to 85%, 50% to 84%, 50% to 83%, 50% to 82%, 50% to 81%, 50% to 80%, 50% to 79%, 50% to 78%, 50% to 77%, 50% to 76%, 50% to 75%, 50% to 74%, 50% to 73%, 50% to 72%, 50% to 71%, 50% to 70%, 50% to 69%, 50% to 68%, 50% to 67%, 50% to 66%, 50% to 65%, 50% to 64%, 50% to 63%, 50% to 62%, 50% to 61%, 50% to 60%, 50% to 59%, 50% to 58%, 50% to 57%, 50% to 56%, 50% to 55%, 50% to 54%, 50% to 53%, 50% to 52%, or 50% to 51%.

In some embodiments, the solvent may be an organosulfuric compound. The solvent may comprise at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof. In some embodiments, the solvent may comprise sulfolane. In some embodiments, the solvent may comprise methanesulfonic acid (MSA). In some embodiments, the composition comprising sulfolane, may achieve improved etching uniformity compared to etching uniformity using MSA. In some embodiments, the composition comprising sulfolane, may achieve improved etching uniformity compared to etching uniformity using conventional PAN. In some embodiments, the composition comprising MSA, may achieve improved etching uniformity compared to etching uniformity using conventional PAN.

In some embodiments, the solvent is selected from the group consisting of methanol, ethanol, isopropanol, butanol, pentanol, hexanol, 2-ethyl-1-hexanol, heptanol, octanol, ethylene glycol, propylene glycol, butylene glycol, butylene carbonate, ethylene carbonate, propylene carbonate, dipropylene glycol, diethylene 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, 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, 2,3-dihydrodecafluoropentane, ethyl perfluorobutylether, methyl perfluorobutylether, dimethyl sulfoxide (DMSO), sulfolane, 4-methyl-2-pentanol, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, 3-methyl-2-oxazolidone, N-methylmorpholine N-oxide, trimethylamine N-oxide and combinations thereof. Preferably, the at least one solvent comprises water, most preferably deionized water. When present, preferably the at least one organic solvent comprises at least one species selected from the group consisting of a glycol ether (e.g., diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether), DMSO, sulfolane, methanesulfonic acid, or combinations thereof.

In some embodiments, the composition comprises less than 50% by weight of an acetic acid based on a total weight of the composition. For example, in some embodiments, the composition comprises less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, less than 20%, less than 15%, less than 10%, less than 5% by weight of an acetic acid based on a total weight of the composition. In some embodiments, the composition comprises 1% to 50%, 1% to 45%, 1% to 40%, 1% to 35%, 1% to 30%, 1% to 25%, 1% to 20%, 1% to 15%, 1% to 10%, or 1% to 5% by weight of an acetic acid based on a total weight of the composition. The acetic acid may suppress the galvanic reaction between molybdenum and other non-molybdenum materials. In some embodiments, the composition does not comprise an acetic acid.

In some embodiments, the composition further comprises 0.1% to 20% by weight of a stabilizer based on the total weight of the composition, or any range or subrange between 0.1% and 20%. For example, in some embodiments, the composition comprises 1% to 20%, 1% to 15%, 1% to 10%, or 5% to 20% by weight of a stabilizer based on the total weight of the composition. In some embodiments, the composition comprises 1% to 20%, 2% to 20%, 3% to 20%, 4% to 20%, 5% to 20%, 6% to 20%, 7% to 20%, 8% to 20%, 9% to 20%, 10% to 20%, 11% to 20%, 12% to 20%, 13% to 20%, 14% to 20%, 15% to 20%, 16% to 20%, 17% to 20%, 18% to 20%, or 19% to 20% by weight of a stabilizer based on the total weight of the composition. In some embodiments, the composition comprises 0.1% to 19%, 0.1% to 18%, 0.1% to 17%, 0.1% to 16%, 0.1% to 15%, 0.1% to 14%, 0.1% to 13%, 0.1% to 12%, 0.1% to 11%, 0.1% to 10%, 0.1% to 9%, 0.1% to 8%, 0.1% to 7%, 0.1% to 6%, 0.1% to 5%, 0.1% to 4%, 0.1% to 3%, 0.1% to 2%, or 0.1% to 1% by weight of a stabilizer based on the total weight of the composition. The stabilizer may reduce or prevent the decomposition of an oxidant. The stabilizer may remove or otherwise trap metal impurities resulting from the removal of the molybdenum material.

The stabilizer may comprise at least one of an organic acid, a nitrogen-containing heterocycle, an amine compound, or any combination thereof. Non-limiting examples of the stabilizer include, for example and without limitation, at least one of aminoethylethanolamine, N-methylaminoethanol, aminoethoxyethanol, dimethylaminoethoxyethanol, diethanolamine, N-methyldiethanolamine, monoethanolamine (MEA), triethanolamine (TEA), 1-amino-2-propanol, 2-amino-1-butanol, isobutanolamine, triethylenediamine, 4-(2-hydroxyethyl) morpholine (HEM), ethylenediamine tetraacetic 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, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine, valine, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), 1,5,9-triazacyclododecane-N,N′,N″-tris(methylenephosphonic acid) (DOTRP), 1,4,7,10-tetraazacyclododecane-N,N′,N″,N′″-tetrakis(methylenephosphonic acid) (DOTP), nitrilotris(methylene)triphosphonic acid, diethylenetriaminepentakis(methylene phosphonic acid) (DETAP), aminotri(methylene phosphonic acid), bis(hexamethylene)triamine pentamethylene phosphonic acid, 1,4,7-triazacyclononane-N,N′,N″-tris(methylenephosphonic acid (NOTP), hydroxyethyldiphosphonate, nitrilotris(methylene)phosphonic acid, 2-phosphono-butane-1,2,3,4-tetracarboxylic, carboxyethyl phosphonic acid, aminoethyl phosphonic acid, glyphosate, ethylene diamine tetra(methylenephosphonic acid) phenylphosphonic acid, oxalic acid, succinnic acid, maleic acid, malic acid, malonic acid, adipic acid, phthalic acid, lactic acid, citric acid, sodium citrate, potassium citrate, ammonium citrate, tricarballylic acid, trim ethylolpropionic acid, tartaric acid, glucuronic acid, 2-carboxypyridine, 4,5-dihydroxy-1,3-benzenedisulfonic acid disodium salt, lysine, poly-L-lysine (PLL), poly-D-lysine (PDL), ε-poly-L-lysine (EPL), Aspartame, Gly-His-Lys (CAS: 49557-75-7), Carnosine, Anserine, L-Glutathione oxidized or Glutathionesulfonic acid and combinations thereof. Preferably, the complexing agent comprises benzotriazole, 1-hydroxyethylidene-1,1-diphosphonic acid (HEDP), lactic acid, citric acid, benzotriazole, lysine, poly-L-lysine (PLL), poly-D-lysine (PDL), ¿-poly-L-lysine (EPL), Gly-His-Lys (CAS: 49557-75-7), benzaor any combination thereof.

The stabilizer may comprise at least one of a citric acid, a benzotriazole (BTA), poly-L-lysine (PLL), poly-D-lysine (PDL), ¿-poly-L-lysine (EPL), Aspartame, Gly-His-Lys (CAS: 49557-75-7), Carnosine, Anserine, L-Glutathione oxidized, Glutathionesulfonic, or any combination thereof. In some embodiments, the stabilizer comprises a citric acid. In some embodiments, the stabilizer comprises a benzotriazole. In some embodiments, the stabilizer comprises poly-L-lysine (PLL). In some embodiments, the stabilizer comprises poly-D-lysine (PDL). In some embodiments, the stabilizer comprises ε-poly-L-lysine (EPL). In some embodiments, the stabilizer comprises Aspartame. In some embodiments, the stabilizer comprises Gly-His-Lys (CAS: 49557-75-7). In some embodiments, the stabilizer comprises Carnosine. In some embodiments, the stabilizer comprises Anserine. In some embodiments, the stabilizer comprises L-Glutathione oxidized. In some embodiments, the stabilizer comprises Glutathionesulfonic.

The composition may further comprise 0.1% to 10% by weight of an inhibitor based on the total weight of the composition, or any range or subrange between 0.1% and 10%. For example, in some embodiments, the composition further comprises 0.1% to 9%, 1% to 8%, 2% to 7%, 3% to 6%, or 4% to 5% by weight of an inhibitor based on the total weight of the composition. In some embodiments, the composition further comprises 0.1% to 9%, 0.1% to 8%, 0.1% to 7%, 0.1% to 6%, 0.1% to 5%, 0.1% to 4%, 0.1% to 3%, 0.1% to 2%, or 0.1% to 1% by weight of an inhibitor based on the total weight of the composition. In some embodiments, the composition further comprises 0.5% to 10%, 1% to 10%, 2% to 10%, 3% to 10%, 4% to 10%, 5% to 10%, 6% to 10%, 7% to 10%, 8% to 10%, or 9% to 10% by weight of an inhibitor based on the total weight of the composition.

The inhibitor may be used to protect a top layer of the molybdenum material during the molybdenum layer removal. To achieve uniformity, the inhibitor may protect molybdenum oxide on the top layer of the molybdenum material. In some embodiments, to achieve uniformity molybdenum oxide may be etched on the top layer of molybdenum material.

The inhibitor may comprise a quaternary ammonium compound. In some embodiments, a quaternary ammonium compound comprises a nitrogen-containing salt having four (4) bonds. The quaternary ammonium compound may be a base. Non-limiting examples of the quaternary ammonium compound include, for example and without limitation, at least one of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), tributylmethylammonium hydroxide (TBMAH), benzyltrimethylammonium hydroxide (BTMAH), or any combination thereof. In some embodiments, the quaternary ammonium compound may be at least one of, benzyldimethyldodecylammonium chloride, 1-dodecylpyridinium chloride, 1-methyl-3-N-octylimidazolium chloride, 1-methyl-3-N-octylimidazolium chloride, and 1-decyl-3-methylimidazolium chloride, or any combination thereof.

In some embodiments, the inhibitor comprises at least one of a tetraalkyl ammonium hydroxide, a tributylmethylammonium hydroxide (TBMAH), a benzyltrimethylammonium hydroxide (BTMAH), a choline hydroxide, an ethyltrimethylammonium hydroxide, a tris(2-hydroxyethyl)methyl ammonium hydroxide, a diethyldimethylammonium hydroxide, or any combination thereof.

The composition when tested according to ASTM D93: 20 Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, 2020, may have a flash point of at least 100° C. For example, in some embodiments, the flash point may be at least 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., or 200° C.

In some embodiments, the composition may comprise a phosphorus oxoacid, an oxidant, and a solvent. The solvent may comprise a compound having at least one sulfur-oxygen double bond. In some embodiments, the sulfur-oxygen double bond may be polar. The solvent may comprise at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof. In some embodiments, the solvent may comprise sulfolane. In some embodiments, the solvent may comprise methanesulfonic acid (MSA).

In some embodiments, the composition comprises 50% to 95% by weight of the solvent based on a total weight of the composition. For example, in some embodiments, the weight of the solvent based on a total weight of the composition may be 55% to 90%, 60% to 85%, 65% to 80%, or 70% to 75%. In some embodiments, the weight of the solvent based on a total weight of the composition may be 51% to 95%, 52% to 95%, 53% to 95%, 54% to 95%, 55% to 95%, 56% to 95%, 57% to 95%, 58% to 95%, 59% to 95%, 60% to 95%, 61% to 95%, 62% to 95%, 63% to 95%, 64% to 95%, 65% to 95%, 66% to 95%, 67% to 95%, 68% to 95%, 69% to 95%, 70% to 95%, 71% to 95%, 72% to 95%, 73% to 95%, 74% to 95%, 75% to 95%, 76% to 95%, 77% to 95%, 78% to 95%, 79% to 95%, 80% to 95%, 81% to 95%, 82% to 95%, 83% to 95%, 84% to 95%, 85% to 95%, 86% to 95%, 87% to 95%, 88% to 95%, 89% to 95%, 90% to 95%, 91% to 95%, 92% to 95%, 93% to 95%, or 94% to 95%. In some embodiments, the weight of the solvent based on a total weight of the composition may be 50% to 94%, 50% to 93%, 50% to 92%, 50% to 91%, 50% to 90%, 50% to 89%, 50% to 88%, 50% to 87%, 50% to 86%, 50% to 85%, 50% to 84%, 50% to 83%, 50% to 82%, 50% to 81%, 50% to 80%, 50% to 79%, 50% to 78%, 50% to 77%, 50% to 76%, 50% to 75%, 50% to 74%, 50% to 73%, 50% to 72%, 50% to 71%, 50% to 70%, 50% to 69%, 50% to 68%, 50% to 67%, 50% to 66%, 50% to 65%, 50% to 64%, 50% to 63%, 50% to 62%, 50% to 61%, 50% to 60%, 50% to 59%, 50% to 58%, 50% to 57%, 50% to 56%, 50% to 55%, 50% to 54%, 50% to 53%, 50% to 52%, or 50% to 51%.

The composition when tested according to ASTM D93: 20, may have a flash point of at least 100° C. For example, in some embodiments, the flash point may be at least 110° C., 120° C., 130° C., 140° C., 150° C., 160° C., 170° C., 180° C., 190° C., or 200° C.

FIG. 1 is a flow diagram of a method for molybdenum etching. As shown in FIG. 1, the method 100 include one or more of the following steps: obtaining 102 a structure comprising a plurality of recesses and a molybdenum material located in the plurality of recesses; and contacting 104 the structure with a composition to remove at least a portion of the molybdenum material.

At step 102, in some embodiments, the method 100 comprises obtaining a structure. In some embodiments, the structure comprises a plurality of recesses. In some embodiments, the structure comprises a molybdenum material located in the plurality of recesses. In some embodiments, the structure may be a 3D NAND structure.

At step 104, in some embodiments, the method 100 comprises contacting the structure with a composition to remove at least a portion of the molybdenum material. In some embodiments, the composition comprises a phosphorus oxoacid, an oxidant, and at least 50% by weight of a solvent based on a total weight of the composition. The solvent may comprise a compound having at least one sulfur-oxygen double bond. The solvent may comprise at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof. In some embodiments, the composition comprises 50% to 95% by weight of the solvent based on the total weight of the composition, described herein.

In some embodiments, the composition comprises a phosphorus oxoacid, an oxidant, and a solvent. The solvent may comprise a compound having at least one sulfur-oxygen double bond. The composition when tested according to ASTM D93: 20, may have a flash point of at least 100° C. In some embodiments, the composition comprises 50% to 95% by weight of the solvent based on the total weight of the composition, described herein. The solvent may comprise at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof.

In some embodiments, the composition comprises C₁₂-pyrolytic carbon. In some embodiments, the composition comprises 0.01% to 0.1% by weight of the C₁₂-pyrolytic carbon based on the total weight of the composition, or any range or subrange between 0.01% and 0.1%. For example, in some embodiments, the weight of the C₁₂-pyrolytic carbon based on the total weight of the composition may be 0.01% to 0.09%, 0.01% to 0.08%, 0.01% to 0.07%, 0.01% to 0.06%, 0.01% to 0.05%, 0.01% to 0.04%, 0.01% to 0.03%, or 0.01% to 0.02%. In some embodiments, the weight of the C₁₂-pyrolytic carbon based on the total weight of the composition may be 0.02% to 0.1%, 0.03% to 0.1%, 0.04% to 0.1%, 0.05% to 0.1%, 0.06% to 0.1%, 0.07% to 0.1%, 0.08% to 0.1%, or 0.09% to 0.1%.

In some embodiments, the composition comprises benzethonium chloride. In some embodiments, the composition comprises 0.01% to 0.1% by weight of the benzethonium chloride based on the total weight of the composition, or any range or subrange between 0.01% and 0.1%. For example, in some embodiments, the weight of the benzethonium chloride based on the total weight of the composition may be 0.01% to 0.09%, 0.01% to 0.08%, 0.01% to 0.07%, 0.01% to 0.06%, 0.01% to 0.05%, 0.01% to 0.04%, 0.01% to 0.03%, or 0.01% to 0.02%. In some embodiments, the weight of the benzethonium chloride based on the total weight of the composition may be 0.02% to 0.1%, 0.03% to 0.1%, 0.04% to 0.1%, 0.05% to 0.1%, 0.06% to 0.1%, 0.07% to 0.1%, 0.08% to 0.1%, or 0.09% to 0.1%.

In some embodiments, the composition has a pH of 0 to 7, or any range or subrange between 0 and 7. For example, in some embodiments, the composition has a pH of 0 to 7, 0 to 6, 0 to 5, 0 to 4, 0 to 3, 0 to 2, 0 to 1, 1 to 7, 2 to 7, 3 to 7, 4 to 7, 5 to 7, or 6 to 7.

In some embodiments, the contacting comprises bringing the structure and the composition into close or immediate proximity. In some embodiments, the contacting comprises bringing the plurality of recesses and the composition into close or immediate proximity. In some embodiments, the contacting comprises bringing the molybdenum material and the composition into close or immediate proximity. In some embodiments, the contacting comprises bringing the structure and the composition into direct physical contact. In some embodiments, the contacting comprises bringing the plurality of recesses into direct physical contact. In some embodiments, the contacting comprises bringing the molybdenum materials into direct physical contact. In some embodiments, the contacting comprises adding the structure to the composition, or vice versa. In some embodiments, the contacting comprises mixing the structure and the composition. In some embodiments, the contacting comprises stirring the structure and the composition. In some embodiments, the contacting comprises agitating the structure and the composition. In some embodiments, the contacting comprises flowing the composition through a vessel containing the structure. In some embodiments, the contacting comprises flowing the composition over the structure. In some embodiments, the contacting comprises shaking the composition on the structure. In some embodiments, the contacting proceeds under conditions sufficient for removing at least a portion of the molybdenum material located in the plurality of recesses.

In some embodiments, the contacting comprises removing the molybdenum material from the structure. In some embodiments, the contacting comprises displacing the molybdenum material from the structure. In some embodiments, the contacting comprises disassociating the molybdenum material from the structure. In some embodiments, the contacting comprises breaking a bond located between the molybdenum material from the structure. In some embodiments, the contacting comprises extracting the molybdenum material from the structure. In some embodiments, the contacting comprises releasing the molybdenum material from the structure.

FIG. 2 is an illustration of the results of a method for the removal of molybdenum, where a 3D NAND structure with molybdenum is subjected to a solvent-based composition. The deviation line 208 represents a target of 0%. After contacting the structure 200 with the composition, the top layer 202, middle layer 204, and bottom layer 208 is shown with a balance recess difference.

Any one or more of the embodiments disclosed herein shall be understood to be combinable without departing from the scope or spirit of the disclosure.

Example 1

Various compositions for etching molybdenum were prepared and the performance of each was compared to a conventional PAN composition. All samples were prepared with the following reported in Table 1 below:

Each of the compositions had a pH ranging from 0 to 7. More specifically, the pH ranged from 0 to 2.

Each of the compositions were applied to a structure comprising a plurality of recesses, and a molybdenum material disposed in the plurality of recesses, at 30° C. for 5 minutes and 10 minutes contact period as reported in Table 2 below.

After the contact period, the variation of average depth of the molybdenum material in a top portion, a middle portion, and a bottom portion of the structure was measured and is reported in Table 3 below.

The top, middle, or bottom shift characterizes a structure (e.g., a molybdenum structure in FIG. 2) that is treated with the compositions disclosed herein (e.g., compositions found in Table 1) for a specific duration. Each of the designations (e.g., low, medium, and high) is calculated by taking the difference between the etching depth at the top, middle, or bottom portion of the structure and the average etching depth across the structure. The difference is then divided by the average etching depth of the structure and one of the low, medium, and high designations is assigned.

As shown, the control had a higher molybdenum recess on the top layer, represented as the top shift*. Formulations that included the solvents sulfolane or MSA, resulted in an improved top-to-bottom uniformity compared to the control. Overall, Sample 4 which included 80% sulfolane, had the best top-to-bottom recess difference represented by a low variance.

Aspects

Various Aspects are described below. It is to be understood that any one or more of the features recited in the following Aspect(s) can be combined with any one or more other Aspect(s).

Aspect 1. A composition for etching molybdenum, the composition comprising:

• • a phosphoric acid;
  • a nitric acid; and
  • at least 50% by weight of a solvent based on a total weight of the composition,
    • wherein the solvent comprises a compound having at least one sulfur-oxygen double bond.
      Aspect 2. The composition according to Aspect 1, wherein the composition comprises 1% to 30% by weight of the phosphoric acid based on the total weight of the composition.
      Aspect 3. The composition according to any one of Aspects 1-2, wherein the composition comprises 0.1% to 20% by weight of the nitric acid based on the total weight of the composition.
      Aspect 4. The composition according to any one of Aspects 1-3, wherein the composition comprises 50% to 95% by weight of the solvent based on the total weight of the composition.
      Aspect 5. The composition according to any one of Aspects 1-4, wherein the composition comprises less than 50% by weight of an acetic acid based on a total weight of the composition.
      Aspect 6. The composition according to any one of Aspects 1-5, wherein the composition does not comprise an acetic acid.
      Aspect 7. The composition according to any one of Aspects 1-6, wherein the composition further comprises:

0.1% to 20% by weight of a stabilizer based on the total weight of the composition.

Aspect 8. The composition according to any one of Aspects 1-7, wherein the stabilizer comprises at least one of an organic acid, a nitrogen-containing heterocycle, an amine compound, or any combination thereof.
Aspect 9. The composition according to any one of Aspects 1-8, wherein the stabilizer comprises at least one of a citric acid, a benzotriazole, or any combination thereof.
Aspect 10. The composition according to any one of Aspects 1-9, wherein the composition further comprises:

• • 0.1% to 10% by weight of an inhibitor based on the total weight of the composition.
    Aspect 11. The composition according to any one of Aspects 1-10, wherein the inhibitor comprises a quaternary ammonium compound.
    Aspect 12. The composition of claim 10, wherein the inhibitor comprises at least one of a tetraalkyl ammonium hydroxide, a tributylmethylammonium hydroxide (TBMAH), a benzyltrimethylammonium hydroxide (BTMAH), a choline hydroxide, an ethyltrimethylammonium hydroxide, a tris(2-hydroxyethyl)methyl ammonium hydroxide, a diethyldimethylammonium hydroxide, or any combination thereof.
    Aspect 13. The composition according to any one of Aspects 1-12, wherein the solvent comprises at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof.
    Aspect 14. The composition according to any one of Aspects 1-13, wherein the composition, when tested according to ASTM D93-20: Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, has a flash point of at least 100° C.
    Aspect 15. A composition comprising:
  • a phosphorous oxoacid;
  • an oxidant; and
  • a solvent,
    • wherein the solvent comprises a compound having at least one sulfur-oxygen double bond;
    • wherein the composition, when tested according to ASTM D93-20: Standard Test Methods for Flash Point by Pensky-Martens Closed Cup Tester, has a flash point of at least 100° C.
      Aspect 16. The composition according to Aspect 15, wherein the composition comprises 50% to 95% by weight of the solvent based on a total weight of the composition.
      Aspect 17. The composition according to any one of Aspects 15-16, wherein the solvent comprises at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof.
      Aspect 18. A method comprising:
  • obtaining a structure,
    • wherein the structure comprises:
      • a plurality of recesses; and
      • a molybdenum material located in the plurality of recesses; and
  • contacting the structure with a composition to remove at least a portion of the molybdenum material,
    • wherein the composition comprises:
      • a phosphoric acid;
      • a nitric acid; and
      • at least 50% by weight of a solvent based on a total weight of the composition,
        • wherein the solvent comprises a compound having at least one sulfur-oxygen double bond.
          Aspect 19. The method according to Aspect 18, wherein the composition comprises 50% to 95% by weight of the solvent based on the total weight of the composition.
          Aspect 20. The method according to any one of Aspects 18-19, wherein the solvent comprises at least one of sulfolane, methanesulfonic acid (MSA), or any combination thereof.