Etchant compositions and related methods

Abstract

An etchant composition is provided for selectively etching silicon nitride in the presence of silicon oxide and polysilicon. The etchant composition can achieve passivation of at least one of silicon oxide, polysilicon, or any combination thereof while selectively etching silicon nitride in a single step by applying the etchant composition to a substrate. The etchant composition may include at least 60 wt. % phosphoric acid based on the total weight of the etchant composition, at least 1 wt. % water based on the total weight of the etchant composition, and no more than 2 wt. % metal oxidizer based on the total weight of the etchant composition.

Description

[Technical Field]

[0001] The present disclosure relates to etchant compositions and related methods for selective etching. [Background technology]

[0002] The fabrication of microelectronic devices involves the removal of materials by etching, which may also result in the undesired removal of other materials. Summary of the Invention

[0003] Some embodiments relate to an etchant composition. In some embodiments, the etchant composition comprises at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition. In some embodiments, the etchant composition comprises at least 3 wt. % water, based on the total weight of the etchant composition. In some embodiments, the etchant composition comprises 2 wt. % or less of a metal oxidizing agent, based on the total weight of the etchant composition.

[0004] Some embodiments relate to methods for selectively etching silicon nitride. In some embodiments, the method includes obtaining a substrate. In some embodiments, the substrate includes a surface comprising silicon nitride. In some embodiments, the substrate includes a surface comprising silicon oxide. In some embodiments, the substrate includes a surface comprising polysilicon. In some embodiments, the method includes obtaining an etchant composition. In some embodiments, the etchant composition includes at least 60 wt.% phosphoric acid, based on the total weight of the composition. In some embodiments, the etchant composition includes at least 3 wt.% water, based on the total weight of the composition. In some embodiments, the etchant composition includes 2 wt.% or less of a metal oxidant, based on the total weight of the composition. In some embodiments, the method includes contacting a substrate with the etchant composition.

[0005] Some embodiments relate to methods for preparing an etchant composition. In some embodiments, the method includes obtaining at least one of a metal oxidizing agent, phosphoric acid, and water. In some embodiments, the method includes contacting the metal oxidizing agent, phosphoric acid, and water to form the etchant composition. In some embodiments, the etchant composition includes at least 60 wt.% phosphoric acid based on the total weight of the composition. In some embodiments, the etchant composition includes at least 3 wt.% water based on the total weight of the composition. In some embodiments, the etchant composition includes 2 wt.% or less of a metal oxidizing agent based on the total weight of the composition.

[0006] Some embodiments of the present disclosure are described herein, by way of example only, with reference to the accompanying drawings. Referring now in detail and specifically to the drawings, it is emphasized that the illustrated embodiments are by way of example and for illustrative purposes of illustrating embodiments of the present disclosure. In this regard, the description made with the drawings will make apparent to those skilled in the art how embodiments of the present disclosure may be practiced. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a flowchart of a method for selective etching of silicon nitride, according to some embodiments. [Figure 2] 1 is a schematic diagram of a method for selective etching of silicon nitride, according to some embodiments. [Figure 3] 1 is a flowchart of a method for selective etching of silicon nitride, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0008] Among these disclosed benefits and improvements, other objects and advantages of the present disclosure will become apparent from the following description taken in conjunction with the accompanying drawings. While detailed embodiments of the present disclosure are disclosed herein, it should be understood that the disclosed embodiments are merely exemplary of the present disclosure, which may be embodied in various forms. Moreover, each of the examples provided with respect to various embodiments of the present disclosure is intended to be illustrative and not limiting.

[0009] All prior patents and publications referenced herein are incorporated by reference in their entirety.

[0010] Throughout the specification and claims, the following terms take the meanings expressly associated therewith herein, unless the context clearly dictates otherwise. The phrases "in one embodiment," "in an embodiment," and "in some embodiments," when used herein, do not necessarily refer to the same embodiment, but may. Additionally, the phrases "in another embodiment" and "in some other embodiments," when used herein, do not necessarily refer to different embodiments, but may. It is intended that all embodiments of the present disclosure be combinable without departing from the scope or spirit of the disclosure.

[0011] As used herein, the term "alkyl" refers to a hydrocarbon compound having 1 to 30 carbon atoms. An alkyl having n carbon atoms is referred to as "C n For example, "C alkyl" may include n-propyl and isopropyl. Alkyl having a range of carbon atoms, such as 1 to 30 carbon atoms, may be specified as C1-C 30 In some embodiments, alkyl is linear. In some embodiments, alkyl is branched. In some embodiments, alkyl is substituted. In some embodiments, alkyl is unsubstituted. In some embodiments, alkyl is C1-C 10Alkyl, C1-C9 alkyl, C1-C8 alkyl, C1-C7 alkyl, C1-C6 alkyl, C1-C5 alkyl, C1-C4 alkyl, C1-C3 alkyl, C2-C 10 Alkyl, C3-C 10 Alkyl, C4-C 10 Alkyl, C5-C 10 Alkyl, C6-C 10 Alkyl, C7-C 10 Alkyl, C8-C 10 In some embodiments, the alkyl comprises or is selected from the group consisting of at least one of methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, isobutyl, sec-butyl, n-pentyl, 1,1-dimethylethyl (t-butyl), n-pentyl, isopentyl, n-hexyl, isohexyl, 3-methylhexyl, 2-methylhexyl, heptyl, octyl, nonyl, decyl, dodecyl, octadecyl, or any combination thereof.

[0012] As used herein, the term "alkenyl" refers to a hydrocarbon chain radical having 1 to 10 carbon atoms and at least one carbon-carbon double bond. Examples of alkenyl groups include, but are not limited to, vinyl, allyl, 1-methylvinyl, 1-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1,3-pentadienyl, 2,4-pentadienyl, 1,4-pentadienyl, 3-methyl-2-butenyl, At least one of 1-hexenyl, 2-hexenyl, 3-hexenyl, 1,3-hexadienyl, 1,4-hexadienyl, 2-methylpentenyl, 1-heptenyl, 3-heptenyl, 1-octenyl, 1,3-octadienyl, 1-nonenyl, 2-nonenyl, 3-nonenyl, 1-decenyl, 3-decenyl, 1-undecenyl, oleyl, linoleyl, linolenyl, or any combination thereof.

[0013] As used herein, the term "alkynyl" refers to a hydrocarbon chain radical having 1 to 10 carbon atoms and at least one carbon-carbon triple bond. Examples of alkynyl groups include, but are not limited to, at least one of ethynyl, propynyl, n-butynyl, n-pentynyl, 3-methyl-1-butynyl, n-hexynyl, methyl-pentynyl, or any combination thereof.

[0014] As used herein, the term "alkoxy" refers to a radical of the formula -OR, where R is alkyl as defined herein. In some embodiments, the alkoxy may comprise, consist essentially of, or be selected from the group consisting of at least one of methoxy, ethoxy, methoxy, ethoxy, n-propoxy, 1-methylethoxy (isopropoxy), n-butoxy, iso-butoxy, sec-butoxy, tert-butoxy, or any combination thereof.

[0015] As used herein, the terms “amine,” “alkylamino,” and the like refer to a group having the formula —N(R a R b R c ) in which R a , R b , and R cis each independently hydrogen or alkyl, as defined herein. In some embodiments, the term "amine" includes amino, as defined herein. In some embodiments, the amine may comprise, consist of, or consist essentially of a primary amine, a secondary amine, a tertiary amine, or a quaternary amine. In some embodiments, the amine may comprise, consist of, or consist essentially of an alkyl amine, a dialkyl amine, or a trialkyl amine. In some embodiments, the amine may comprise, consist of, or consist essentially of at least one of, or may be selected from the group consisting of, methylamine, dimethylamine, ethylamine, diethylamine, isopropylamine, di-isopropylamine, butylamine, sec-butylamine, tert-butylamine, di-sec-butylamine, isobutylamine, di-isobutylamine, di-tert-pentylamine, ethylmethylamine, isopropyl-n-propylamine, or any combination thereof.Examples of alkylamines include, but are not limited to, one or more of the following: primary alkylamines such as, but not limited to, methylamine, ethylamine, n-propylamine, isopropylamine, n-butylamine, sec-butylamine, isobutylamine, t-butylamine, pentylamine, 2-aminopentane, 3-aminopentane, 1-amino-2-methylbutane, 2-amino-2-methylbutane, 3-amino-2-methylbutane, 4-amino-2-methylbutane, hexylamine, 5-amino-2-methylpentane, heptylamine, octylamine, nonylamine, decylamine, undecylamine, dodecylamine, tridecylamine, tetradecylamine, pentadecylamine, hexadecylamine, heptadecylamine, and octadecylamine; primary alkylamines such as, but not limited to, dimethylamine, diethylamine, dipropylamine, diisopropylamine, dibutylamine, diisobutylamine, di-s- ... secondary alkylamines such as ec-butylamine, di-t-butylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dinonylamine, didecylamine, methylethylamine, methylpropylamine, methylisopropylamine, methylbutylamine, methylisobutylamine, methyl-sec-butylamine, methyl-t-butylamine, methylamylamine, methylisoamylamine, ethylpropylamine, ethylisopropylamine, ethylbutylamine, ethylisobutylamine, ethyl-sec-butylamine, ethylamine, ethylisoamylamine, propylbutylamine, and propylisobutylamine; and tertiary alkylamines such as, but not limited to, trimethylamine, triethylamine, tripropylamine, tributylamine, tripentylamine, dimethylethylamine, methyldiethylamine, and methyldipropylamine.Examples of polyamines may include, but are not limited to, one or more of the following: ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, 1,3-diaminobutane, 2,3-diaminobutane, pentamethylenediamine, 2,4-diaminopentane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, N-methylethylenediamine, N,N-dimethylethylenediamine, trimethylethylenediamine, N-ethylethylenediamine, N,N-diethylethylenediamine, triethylethylenediamine, 1,2,3-triaminopropane, hydrazine, tris(2-aminoethyl)amine, tetra(aminomethyl)methane, diethylenetriamine, triethylenetetramine, tetraethylpentamine, heptaethyleneoctamine, nonaethylenediamine, and diazabicycloundecene.

[0016] As used herein, the term "cycloalkyl" refers to a non-aromatic carbocyclic ring attached through a single bond and having 3 to 8 carbon atoms in the ring. The term includes monocyclic non-aromatic carbocyclic rings and polycyclic non-aromatic carbocyclic rings. Two or more cycloalkyls can be fused, bridged, or fused and bridged to give, for example, a polycyclic non-aromatic carbocyclic ring. In some embodiments, a cycloalkyl can comprise, consist of, consist essentially of, or be selected from the group consisting of at least one of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, or any combination thereof.

[0017] As used herein, the term "aryl" refers to a monocyclic or polycyclic aromatic hydrocarbon compound. The number of carbon atoms in an aryl can range from 5 to 100 carbon atoms. In some embodiments, an aryl has 5 to 20 carbon atoms. For example, in some embodiments, an aryl has 6 to 8 carbon atoms, 6 to 10 carbon atoms, 6 to 12 carbon atoms, 6 to 15 carbon atoms, or 6 to 20 carbon atoms. The term "monocyclic," when used as a modifier, refers to an aryl having a single aromatic ring structure. The term "polycyclic," when used as a modifier, refers to an aryl having two or more aromatic ring structures that may be fused, bridged, spiro, or otherwise linked ring structures. Examples of aryls include, but are not limited to, phenyl, biphenyl, naphthyl, and the like. In some embodiments, at least one carbon atom in an aryl's aromatic ring structure is substituted with a heteroatom, including, but not limited to, at least one of O, N, and the like.

[0018] As used herein, the term "microelectronic device" (or "microelectronic device substrate," or simply "substrate") is used in a manner consistent with the commonly understood meaning of the term in the arts of electronics, microelectronics, and semiconductor fabrication, and refers to, for example, any of a variety of different types: semiconductor substrates; integrated circuits; solid-state memory devices; hard memory disks; read, write, and read-write heads and their mechanical or electronic components; flat panel displays; phase-change memory devices; solar panels and other products containing one or more solar cell devices; photovoltaic cells; and microelectromechanical systems (MEMS) manufactured for use in microelectronics, integrated circuit, energy harvesting, or computer chip applications. It should be understood that the term "microelectronic device" can refer to any in-process microelectronic device or microelectronic device substrate that contains, or is being prepared to contain, functional electronic (current-carrying), functional semiconductor, and insulating structures for ultimate electronic use in a microelectronic device or microelectronic assembly.

[0019] As used herein, the term "silicon nitride" is given a meaning consistent with that of the term as used in the microelectronics and semiconductor fabrication industries. Consistently, silicon nitride refers to materials including thin films made of amorphous silicon nitride having commercially available low levels of other materials or impurities, and potentially variations on the nominal stoichiometry of Si3N4. Silicon nitride may be present as a functional feature of a device, e.g., as a barrier or insulating layer, as part of a microelectronic device substrate, or to function as a material that facilitates multi-step fabrication processes for preparing microelectronic devices.

[0020] As used herein, the term "silicon oxide" is given a meaning consistent with that used in the microelectronics and semiconductor fabrication industries. Consistently, silicon oxide refers to a thin film made of silicon oxide (SiOx), e.g., SiO2, "thermal oxide" (ThOx), or the like. The silicon oxide can be disposed on the substrate by any method, for example, by chemical vapor deposition from tetraethoxysilane (TEOS) or another source, or by thermal deposition. The silicon oxide can advantageously contain commercially useful low levels of other materials or impurities. Silicon oxide may be present as a feature of a microelectronic device, for example, as an insulating layer, or as part of a microelectronic device substrate.

[0021] As used herein, the term "polysilicon" or polycrystalline Si or poly-Si is understood by those skilled in the art to be a polycrystalline form of silicon containing multiple small silicon crystals. It is typically deposited using low pressure chemical vapor deposition (LPCVD) and is often doped n-type or p-type polysilicon. As will be readily understood by those skilled in the art, the degree of doping can vary from lightly doped (e.g., 10 cm -3 ~1018cm -3 range) to highly doped (e.g., 1018 cm -3 The doping concentration can vary from 0.01 to 0.01 (exceeding 0.01). Examples of p-doped materials include polysilicon doped with a dopant species from Group IIIA of the periodic table, such as at least one of boron, aluminum, gallium, indium, or any combination thereof. An n-doped material can be, for example, polysilicon doped with a dopant species from Group IV of the periodic table (silicon, germanium, or tin) or a dopant species from Group V of the periodic table (phosphorus, arsenic, antimony, or bismuth).

[0022] As used herein, the term "based on" is not exclusive and allows for the basis of additional unrecited factors unless the context clearly dictates otherwise. Furthermore, throughout this specification, the meanings of "a," "an," and "the" include plural referents. The meaning of "in" includes "in" and "on."

[0023] Microelectronic device fabrication and semiconductor fabrication can involve material removal by etching. Silicon nitride is an example of a material that is removed during the fabrication of microelectronic devices. For example, silicon nitride can be deposited by chemical vapor deposition onto a substrate as a thin, optionally patterned, layer. During the manufacturing or fabrication process, the silicon nitride layer must be at least partially removed. Etchants can be useful for removing at least a portion of the silicon nitride layer. However, current etchants, in addition to removing silicon nitride, also remove or otherwise damage other materials present, such as, but not limited to, silicon oxide and polysilicon. Removal of or damage to these other materials, including silicon oxide and polysilicon, is undesirable.

[0024] Some embodiments relate to etchant compositions useful in microelectronics manufacturing, including semiconductor fabrication. The etchant compositions disclosed herein exhibit high selectivity for silicon nitride over other materials, including silicon oxide and polysilicon. That is, for example, the etchant compositions disclosed herein can remove silicon nitride without removing or otherwise damaging layers or surfaces containing at least one of silicon oxide, polysilicon, or any combination thereof. The etchant compositions can also exhibit dual functionality in a single application. That is, for example, a single application of the etchant compositions disclosed herein can passivate polysilicon and simultaneously etch silicon nitride at a sufficiently high etch rate while preserving silicon oxide. In other words, the passivation and etching processes can be accomplished in a single process step. These and other advantages will be apparent from the disclosure herein.

[0025] The etchant compositions disclosed herein may include one or more components. In some embodiments, the etchant composition is the result of a combination of one or more components. In some embodiments, the etchant composition is a composition including one or more components. In some embodiments, the etchant composition is a mixture of one or more components. In some embodiments, the etchant composition is derived from a formulation. In some embodiments, the etchant composition is a reaction product of a formulation, where the formulation includes one or more components that undergo a reaction. In some embodiments, the etchant composition is a dissolution product of a formulation, where the formulation includes one or more components that undergo dissolution or solubilization (e.g., dissolving). In some embodiments, the formulation includes one or more components that are inert, where the one or more inert components do not undergo any physical or chemical change.

[0026] The etchant composition may comprise a solution. In some embodiments, the etchant composition comprises a liquid solution. In some embodiments, the etchant composition comprises a liquid solution and at least one solid component. In some embodiments, the etchant composition comprises a slurry. In some embodiments, the etchant composition comprises a suspension. In some embodiments, the etchant composition comprises an emulsion. In some embodiments, the etchant composition comprises a solution of at least one dissolved component. In some embodiments, the etchant composition comprises any combination of the foregoing.

[0027] In some embodiments, one or more components may comprise a metal oxidizer, which may include at least one of the following metals: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, or any combination thereof. In some embodiments, the metal oxidizer comprises at least one of a metal sulfate, a metal oxysulfate, a metal oxide, a metal phosphate, a metal dihydrogen phosphate, a metal halide, a metal hydroxide, a metal acid, a metal nitrate, a metal ammonium nitrate, a metal carbonate, any hydrate thereof, or any combination thereof. Examples of metal oxidizers include, but are not limited to, at least one of titanium(IV) oxysulfate, titanium(IV) sulfate hydrate, phosphomolybdic acid hydrate, silicomolybdic acid, molybdenum(VI) oxide, molybdic acid, lanthanum oxide, cerium(IV) sulfate, cerium ammonium nitrate, phosphotungstic acid, vanadium pentoxide, cobalt(III) acetylacetonate, or any combination thereof.

[0028] The metal oxidizing agent may be present in the etchant composition as a dissolved product. For example, in some embodiments, the metal oxidizing agent dissociates into metal oxidizing agents in the etchant composition. In some embodiments, the metal oxidizing agent dissociates into metal cations and anions. In some embodiments, the metal oxidizer comprises at least one cation of the following metals: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, or any combination thereof. In some embodiments, the metal oxidizer comprises a metal cation in its highest oxidation state. In some embodiments, the metal oxidizer comprises a metal cation that is not in its highest oxidation state. Examples of metal oxidants include, but are not limited to, the following: Ti +3、 Ti +4 , V +2 , V +3 , V +4 , V +5 , Co +2 , Co +3 , Ni +2 , Ni +3 , Ni +4 , Mo + , Mo +2 , Mo +3 , Mo +4 , Mo +5 , Mo +6 , Ce + , Ce +2 , Ce +3 , Ce +4 , W +6 , Pt +4 , Rh + , Rh +2 , Rh +3 , Rh +4 , Rh +5 , Gd +3 or any combination thereof.

[0029] The etchant composition may include 0.001 wt. % to 2 wt. % of the metal oxidizing agent, based on the total weight of the etchant composition, or any range or subrange between 0.001% and 2%. For example, in some embodiments, the etchant composition may include 0.02 wt. % to 2 wt. %, 0.03 wt. % to 2 wt. %, 0.04 wt. % to 2 wt. %, 0.05 wt. % to 2 wt. %, 0.06 wt. % to 2 wt. %, 0.07 wt. % to 2 wt. %, 0.08 wt. % to 2 wt. %, 0.09 wt. % to 2 wt. %, 0.1 wt. % to 2 wt. %, 0.2 wt. % to 2 wt. %, 0.3 wt. % to 2 wt. %, 0.4 wt. % to 2 wt. %, 0.5 wt. % to 2 wt. %, 0.6 wt. % to 2 wt. %, 0.7 wt. % to 2 wt. %, 0.8 wt. % to 2 wt. %, 0.9 wt. % to 2 wt. %, 0.1 wt. % to 2 wt. %, 0.2 wt. % to 2 wt. %, 0.3 wt. % to 2 wt. %, 0.4 wt. % to 2 wt. %, 0.5 wt. % to 2 wt. %, 0.6 wt. % to 2 wt. %, 0.7 wt. % to 2 wt. %, 0.8 wt. % to 2 wt. .5wt%~2wt%, 0.6wt%~2wt%, 0.7wt%~2wt%, 0.8wt%~2wt%, 0.9wt%~2wt%, 1wt%~2wt%, 1.1wt%~2wt%, 1.2wt%~2wt%, 1.3wt%~ 2wt%, 1.4wt%~2wt%, 1.5wt%~2wt%, 1.6wt%~2wt%, 1.7wt%~2wt%, 1.8wt%~2wt%, 1.9wt%~2wt%, 0.01wt%~1.9wt%, 0.01wt%~ 1.8wt%, 0.01wt%~1.7wt%, 0.01wt%~1.6wt%, 0.01wt%~1.5wt%, 0.01wt%~1.4wt%, 0.01wt%~1.3wt%, 0.01wt%~1.2wt%, 0.0 1wt%~1.1wt%, 0.01wt%~1wt%, 0.01wt%~0.9wt%, 0.01wt%~0.8wt%, 0.01wt%~0.7wt%, 0.01wt%~0.6wt%, 0.01wt%~0.5wt%, 0.01 wt% to 0.4 wt%, 0.01 wt% to 0.3 wt%, 0.01 wt% to 0.2 wt%, 0.01 wt% to 0.1 wt%, 0.01 wt% to 0.09 wt%, 0.01 wt% to 0.08 wt%, 0.01 wt% to 0.07 wt%, 0.01 wt% to 0.06 wt%, 0.01 wt% to 0.05 wt%, 0.01 wt% to 0.04 wt%, 0.01 wt% to 0.03 wt%, or 0.01 wt% to 0.02 wt% metal oxidizer. In some embodiments, the weight percentages are based on the total weight of the formulation.

[0030] The etchant composition may comprise 0.01 wt. % to 0.5 wt. % of the metal oxidizing agent, based on the total weight of the etchant composition, or any range or subrange between 0.01% and 0.5%. In some embodiments, the etchant composition may comprise 0.01 wt. % to 0.5 wt. %, 0.01 wt. % to 0.45 wt. %, 0.01 wt. % to 0.4 wt. %, 0.01 wt. % to 0.35 wt. %, 0.01 wt. % to 0.3 wt. %, 0.01 wt. % to 0.25 wt. %, 0.01 wt. % to 0.2 wt. %, 0.01 wt. % to 0.15 wt. %, 0.01 wt. % to 0.1 wt. %, 0.01 wt. % to 0.05 wt. %, 0.02 wt. % to 0.5 wt. %, 0.03 wt. % to 0.5 wt. %, based on the total weight of the etchant composition. %, 0.04% to 0.5%, 0.05% to 0.5%, 0.06% to 0.5%, 0.07% to 0.5%, 0.08% to 0.5%, 0.09% to 0.5%, 0.1% to 0.5%, 0.15% to 0.5%, 0.2% to 0.5%, 0.25% to 0.5%, 0.3% to 0.5%, 0.35% to 0.5%, 0.4% to 0.5%, or 0.45% to 0.5% by weight of metal oxidizer. In some embodiments, the weight percentages are based on the total weight of the formulation.

[0031] The etchant composition may comprise 2 wt% or less of a metal oxidant, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition may comprise 1.9 wt% or less, 1.8 wt% or less, 1.7 wt% or less, 1.6 wt% or less, 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, 0.2 wt% or less, or 1.9 wt% or less, 1.8 wt% or less, 1.7 wt% or less, 1.6 wt% or less, 1.5 wt% or less, 1.4 wt% or less, 1.3 wt% or less, 1.2 wt% or less, 1.1 wt% or less, 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.4 wt% or less, 0.3 wt% or less, 0.2 wt% or less, based on the total weight of the etchant composition. % or less, 0.1% or less, 0.09% or less, 0.08% or less, 0.07% or less, 0.06% or less, 0.05% or less, 0.04% or less, 0.03% or less, 0.02% or less, 0.01% or less, 0.009% or less, 0.008% or less, 0.007% or less, 0.006% or less, 0.005% or less, 0.004% or less, 0.003% or less, 0.002% or less by weight of a metal oxidizer.

[0032] The etchant composition may comprise 0.001 wt. % to 2 wt. % of the metal oxidizer, or any range or subrange between 0.001% and 2%, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition may comprise 0.001 wt. % to 1 wt. %, 0.02 wt. % to 2 wt. %, 0.03 wt. % to 2 wt. %, 0.04 wt. % to 2 wt. %, 0.05 wt. % to 2 wt. %, 0.06 wt. % to 2 wt. %, 0.07 wt. % to 2 wt. %, 0.08 wt. % to 2 wt. %, 0.09 wt. % to 2 wt. %, 0.1 wt. % to 2 wt. %, 0.2 wt. % to 2 wt. %, 0.3 wt. % to 2 wt. %, 0.4 wt. % to 2 wt. %, 0.5 wt. % to 2 wt. %, 0.6 wt. % to 2 wt. %, 0.7 wt. % to 2 wt. %, 0.8 wt. % to 2 wt. %, 0.09 wt. % to 2 wt. %, 0.1 wt. % to 2 wt. %, 0.2 wt. % to 2 wt. %, 0.3 wt. % to 2 wt. %, 0.4 wt. % to 2 wt. %, 0.5 wt. % to 2 wt. %, 0.6 wt. % to 2 wt. %, 0.7 wt. % to 2 wt wt%~2wt%, 0.5wt%~2wt%, 0.6wt%~2wt%, 0.7wt%~2wt%, 0.8wt%~2wt%, 0.9wt%~2wt%, 1wt%~2wt%, 1.1wt%~2wt%, 1.2wt%~2wt %, 1.3wt%~2wt%, 1.4wt%~2wt%, 1.5wt%~2wt%, 1.6wt%~2wt%, 1.7wt%~2wt%, 1.8wt%~2wt%, 1.9wt%~2wt%, 0.01wt%~1.9wt%, 0 .01wt%~1.8wt%, 0.01wt%~1.7wt%, 0.01wt%~1.6wt%, 0.01wt%~1.5wt%, 0.01wt%~1.4wt%, 0.01wt%~1.3wt%, 0.01wt%~1.2wt Amount%, 0.01wt%~1.1wt%, 0.01wt%~1wt%, 0.01wt%~0.9wt%, 0.01wt%~0.8wt%, 0.01wt%~0.7wt%, 0.01wt%~0.6wt%, 0.01wt%~0.5 %, 0.01 wt % to 0.4 wt %, 0.01 wt % to 0.3 wt %, 0.01 wt % to 0.2 wt %, 0.01 wt % to 0.1 wt %, 0.01 wt % to 0.09 wt %, 0.01 wt % to 0.08 wt %, 0.01 wt % to 0.07 wt %, 0.01 wt % to 0.06 wt %, 0.01 wt % to 0.05 wt %, 0.01 wt % to 0.04 wt %, 0.01 wt % to 0.03 wt %, or 0.01 wt % to 0.02 wt % metal oxidizer. In some embodiments, the weight percentages are based on the total weight of the formulation.

[0033] The etchant composition may comprise 0.01 wt. % to 0.5 wt. % of the metal oxidizer, or any range or subrange between 0.01% and 0.5%, based on the total weight of the etchant composition. In some embodiments, the etchant composition may comprise 0.01 wt. % to 0.5 wt. %, 0.01 wt. % to 0.45 wt. %, 0.01 wt. % to 0.4 wt. %, 0.01 wt. % to 0.35 wt. %, 0.01 wt. % to 0.3 wt. %, 0.01 wt. % to 0.25 wt. %, 0.01 wt. % to 0.2 wt. %, 0.01 wt. % to 0.15 wt. %, 0.01 wt. % to 0.1 wt. %, 0.01 wt. % to 0.05 wt. %, 0.02 wt. % to 0.5 wt. %, 0.03 wt. % to 0.5 wt. % based on the total weight of the etchant composition. %, 0.04% to 0.5%, 0.05% to 0.5%, 0.06% to 0.5%, 0.07% to 0.5%, 0.08% to 0.5%, 0.09% to 0.5%, 0.1% to 0.5%, 0.15% to 0.5%, 0.2% to 0.5%, 0.25% to 0.5%, 0.3% to 0.5%, 0.35% to 0.5%, 0.4% to 0.5%, or 0.45% to 0.5% by weight of metal oxidizer. In some embodiments, the weight percentages are based on the total weight of the formulation.

[0034] The etchant composition may comprise 0.001 wt. % to 2 wt. % of the metal oxidant, or any range or subrange between 0.001% and 2%, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition may comprise 0.02 wt. % to 2 wt. %, 0.03 wt. % to 2 wt. %, 0.04 wt. % to 2 wt. %, 0.05 wt. % to 2 wt. %, 0.06 wt. % to 2 wt. %, 0.07 wt. % to 2 wt. %, 0.08 wt. % to 2 wt. %, 0.09 wt. % to 2 wt. %, 0.1 wt. % to 2 wt. %, 0.2 wt. % to 2 wt. %, 0.3 wt. % to 2 wt. %, 0.4 wt. % to 2 wt. %, 0.5 wt. % to 2 wt. %, 0.6 wt. % to 2 wt. %, 0.7 wt. % to 2 wt. %, 0.8 wt. % to 2 wt. %, 0.9 wt. % to 2 wt. %, 0.1 wt. % to 2 wt. %, 0.2 wt. % to 2 wt. %, 0.3 wt. % to 2 wt. %, 0.4 wt. % to 2 wt. %, 0.5 wt. % to 2 wt. %, 0.6 wt. % to 2 wt. %, 0.7 wt. % to 2 wt. %, 0.8 wt. % to 2 wt. %, .5wt%~2wt%, 0.6wt%~2wt%, 0.7wt%~2wt%, 0.8wt%~2wt%, 0.9wt%~2wt%, 1wt%~2wt%, 1.1wt%~2wt%, 1.2wt%~2wt%, 1.3wt%~ 2wt%, 1.4wt%~2wt%, 1.5wt%~2wt%, 1.6wt%~2wt%, 1.7wt%~2wt%, 1.8wt%~2wt%, 1.9wt%~2wt%, 0.01wt%~1.9wt%, 0.01wt%~ 1.8wt%, 0.01wt%~1.7wt%, 0.01wt%~1.6wt%, 0.01wt%~1.5wt%, 0.01wt%~1.4wt%, 0.01wt%~1.3wt%, 0.01wt%~1.2wt%, 0.0 1wt%~1.1wt%, 0.01wt%~1wt%, 0.01wt%~0.9wt%, 0.01wt%~0.8wt%, 0.01wt%~0.7wt%, 0.01wt%~0.6wt%, 0.01wt%~0.5wt%, 0.01 wt% to 0.4 wt%, 0.01 wt% to 0.3 wt%, 0.01 wt% to 0.2 wt%, 0.01 wt% to 0.1 wt%, 0.01 wt% to 0.09 wt%, 0.01 wt% to 0.08 wt%, 0.01 wt% to 0.07 wt%, 0.01 wt% to 0.06 wt%, 0.01 wt% to 0.05 wt%, 0.01 wt% to 0.04 wt%, 0.01 wt% to 0.03 wt%, or 0.01 wt% to 0.02 wt% metal oxidizer. In some embodiments, the weight percentages are based on the total weight of the formulation.

[0035] The etchant composition may comprise 0.001 wt. % to 0.5 wt. % of the metal oxidant, or any range or subrange between 0.001% and 0.5%, based on the total weight of the etchant composition. In some embodiments, the etchant composition may comprise 0.002 wt. % to 0.5 wt. %, 0.004 wt. % to 0.5 wt. %, 0.005 wt. % to 0.5 wt. %, 0.006 wt. % to 0.5 wt. %, 0.008 wt. % to 0.5 wt. %, 0.01 wt. % to 0.5 wt. %, 0.01 wt. % to 0.45 wt. %, or 0.01 wt. % to 0.4 wt. % based on the total weight of the etchant composition. , 0.01wt%~0.35wt%, 0.01wt%~0.3wt%, 0.01wt%~0.25wt%, 0.01wt%~0.2wt%, 0.01wt%~0.15wt%, 0.01 Weight%~0.1wt%, 0.001wt%~0.05wt%, 0.002wt%~0.5wt%, 0.003wt%~0.5wt%, 0.004wt%~0.5wt%, 0.005wt% ~0.5wt%, 0.006wt%~0.5wt%, 0.007wt%~0.5wt%, 0.008wt%~0.5wt%, 0.009wt%~0.5wt%, 0.01wt%~0.0 5wt%, 0.02wt%~0.5wt%, 0.03wt%~0.5wt%, 0.04wt%~0.5wt%, 0.05wt%~0.5wt%, 0.06wt%~0.5wt%, 0.07 % to 0.5 wt%, 0.08 wt% to 0.5 wt%, 0.09 wt% to 0.5 wt%, 0.1 wt% to 0.5 wt%, 0.15 wt% to 0.5 wt%, 0.2 wt% to 0.5 wt%, 0.25 wt% to 0.5 wt%, 0.3 wt% to 0.5 wt%, 0.35 wt% to 0.5 wt%, 0.4 wt% to 0.5 wt%, or 0.45 wt% to 0.5 wt% metal oxidizer. In some embodiments, the weight percentages are based on the total weight of the formulation.

[0036] In some embodiments, one or more components may include phosphoric acid or any derivative thereof. In some embodiments, phosphoric acid is an active component for etching silicon nitride. In some embodiments, phosphoric acid includes solid phosphoric acid. In some embodiments, phosphoric acid is provided in an aqueous phosphoric acid solution. In some embodiments, the aqueous phosphoric acid solution includes at least one of solid phosphoric acid, water, at least one additional component, or any combination thereof. In some embodiments, the aqueous phosphoric acid solution includes 50% to 99% by weight phosphoric acid, based on the total weight of the aqueous phosphoric acid solution, or any range or subrange therebetween. In some embodiments, the aqueous phosphoric acid solution includes 80% to 90% by weight phosphoric acid, based on the total weight of the aqueous phosphoric acid solution. In some embodiments, the aqueous phosphoric acid solution includes 80% to 85% by weight phosphoric acid, based on the total weight of the aqueous phosphoric acid solution. In some embodiments, the remainder of the aqueous phosphoric acid solution includes water or at least one additional component.

[0037] The etchant composition may comprise at least 50 wt% phosphoric acid, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition comprises at least 60 wt%, at least 65 wt%, at least 70 wt%, at least 75 wt%, at least 80 wt%, at least 85 wt%, at least 90%, or at least 95 wt% phosphoric acid, based on the total weight of the etchant composition. In some embodiments, the etchant composition comprises 50 wt% to 99 wt%, 55 wt% to 99 wt%, 60 wt% to 99 wt%, 65 wt% to 99 wt%, 70 wt% to 99 wt%, 75 wt% to 99 wt%, 80 wt% to 99 wt%, 85 wt% to 99 wt%, 90 wt% to 99 wt%, 95 wt% to 99 wt%, 50 wt% to 95 wt%, 50 wt% to 90 wt%, 50 wt% to 85 wt%, 50 wt% to 80 ... The phosphoric acid content may be 75% by weight, 50% by weight to 70% by weight, 50% by weight to 65% by weight, 50% by weight to 60% by weight, 50% by weight to 55% by weight, 70% by weight to 95% by weight, 75% by weight to 95% by weight, 80% by weight to 95% by weight, 85% by weight to 95% by weight, 90% by weight to 95% by weight, 70% by weight to 90% by weight, 70% by weight to 85% by weight, 70% by weight to 80% by weight, 75% by weight to 90% by weight, 75% by weight to 85% by weight, 80% by weight to 90% by weight, or 85% by weight to 90% by weight.

[0038] In some embodiments, one or more components may include water or any derivative thereof. In some embodiments, water is added to adjust silicon nitride selectivity, increase the silicon nitride etch rate, or any combination thereof. The etchant composition may include at least 5 wt.% water, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition includes at least 1 wt.%, at least 3 wt.%, at least 5 wt.%, at least 10 wt.%, at least 15 wt.%, at least 20 wt.%, at least 25 wt.%, at least 30 wt.%, at least 35 wt.%, at least 40 wt.%, or at least 40% water, based on the total weight of the etchant composition. In some embodiments, the etchant composition includes 50 wt.% or less water, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition includes 45 wt.% or less, 40 wt.% or less, 35 wt.% or less, 30 wt.% or less, 25 wt.% or less, 20 wt.% or less, 15 wt.% or less, 10 wt.% or less, or 5 wt.% or less water, based on the total weight of the etchant composition.

[0039] The etching solution composition may comprise 1 wt% to 50 wt% water, or any range or subrange between 1% and 50%, based on the total weight of the etching solution composition. For example, in some embodiments, the etching solution composition may comprise 1 wt% to 45 wt%, 1 wt% to 40 wt%, 1 wt% to 35 wt%, 1 wt% to 30 wt%, 1 wt% to 25 wt%, 1 wt% to 20 wt%, 1 wt% to 15 wt%, 1 wt% to 10 wt%, 1 wt% to 5 wt%, 5 wt% to 45 wt%, 5 wt% to 40 wt%, 5 wt% to 35 wt%, 5 wt% to 30 wt%, 5 wt% to 25 wt%, 5 wt% to 20 wt%, 5 wt% to 15 wt%, 5 wt% to 10 wt%, 10 wt% to 50 wt%, 15 wt% Contains up to 50% by weight, 20% by weight to 50% by weight, 25% by weight to 50% by weight, 30% by weight to 50% by weight, 35% by weight to 50% by weight, 40% by weight to 50% by weight, 45% by weight to 50% by weight, 5% by weight to 25% by weight, 6% by weight to 25% by weight, 8% by weight to 25% by weight, 10% by weight to 25% by weight, 12% by weight to 25% by weight, 14% by weight to 25% by weight, 15% by weight to 25% by weight, 16% by weight to 25% by weight, 18% by weight to 25% by weight, 20% by weight to 25% by weight, 22% by weight to 25% by weight, 24% by weight to 25% by weight, 5% by weight to 24% by weight, 5% by weight to 22% by weight, 5% by weight to 18%, 5% by weight to 16% by weight, 5% by weight to 14% by weight, 5% by weight to 5% by weight water.

[0040] In some embodiments, one or more components may include a fluoride compound or any derivative thereof. In some embodiments, the fluoride compound is added to adjust silicon nitride selectivity, increase the silicon nitride etch rate, or any combination thereof. In some embodiments, the fluoride compound includes at least one of hydrogen fluoride (HF), ammonium fluoride, tetrafluoroboric acid, hexafluorosilicic acid, a compound containing a boron fluoride bond, a compound containing a silicon fluoride bond, tetrabutylammonium tetrafluoroborate (TBA-BF), tetraalkylammonium fluoride, or any combination thereof.

[0041] The etchant composition may include 0.0005% (5 ppm) to 5% by weight of the fluoride compound, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition may include 0.0005% to 0.2%, 0.0006% to 0.2%, 0.0008% to 0.2%, 0.001% to 0.2%, 0.002% (20 ppm) to 0.2%, 0.004% to 0.2%, 0.006% to 0.2%, 0.008% to 0.2%, 0.01% to 0.2%, 0.02% to 0.2%, or 0.02%. %~0.2%, 0.0%~0.2%, 0.05%~0.2%, 0.06%~0.2%, 0.08%~0.2%, 0.1%~0.2%, 0.12%~0.2%, 0.14%~0.2%, 0.15%~0.2%, 0.16%~0.2%, 0.18%~0.2%, 0.0005%~4.5%, 0.0005%~4%, 0.0005%~3 0.5%, 0.0005%~3%, 0.0005%~2.5%, 0.0005%~2%, 0.0005%~1.5%, 0.0005%~1%, 0.0005%~0.5%, 0.0005%~0.4%, 0.0005%~0.3%, 0.0005%~0.2%, 0.0005%~1%, 0.0005%~0.9%, 0.0005%~0 Including 0.8%, 0.0005% to 0.6%, 0.0005% to 0.5%, 0.0005% to 0.4%, 0.0005% to 0.2%, 0.0005% to 0.1%, 0.0005% to 0.05%, 0.0005% to 0.01%, 0.0005% to 0.005%, 0.0005% to 0.001%, or 0.0005% to 0.0009%.

[0042] In some embodiments, the etchant composition does not contain any detectable amount of fluoride compounds.

[0043] In some embodiments, one or more components may include a silicon-containing compound or any derivative thereof. In some embodiments, the silicon-containing compound is added to adjust the selectivity of the etchant composition relative to silicon nitride, to increase the etching rate of the etchant composition relative to silicon nitride, or any combination thereof. In some embodiments, the silicon-containing compound dissolves in the etchant composition and reacts with phosphoric acid to form a silicon-containing compound dissolved in the etchant composition, or any combination thereof. In some embodiments, the silicon-containing compound comprises at least one of silica, tetramethylammonium silicate (TMAS), tetraacetoxysilane, tetraalkoxysilane, tetramethylammonium silicate, N-(3-trimethoxysilylpropyl)diethylenetriamine, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N-(2-aminoethyl)-3-aminopropylsilanetriol, N-(3-trimethoxysilylpropyl)diethylenetriamine, N-(6-aminohexyl)aminopropyltrimethoxysilane, (3-aminopropyl)triethoxysilane, (3-aminopropyl)silanetriol, 3-aminopropylsilanetriol, tetramethoxysilane, tetraethoxysilane, any phosphate ester thereof, or any combination thereof. The amount of silicon-containing compound added to the etching solution composition may include an amount that does not cause the silicon-containing compound to become supersaturated under etching conditions.

[0044] The etching solution composition may contain 0.0005 wt % (5 ppm) to 1 wt % of the silicon-containing compound, based on the total weight of the etching solution composition. For example, in some embodiments, the etchant composition may contain from 0.0006% to 1%, 0.0008% to 1%, 0.001% to 1%, 0.002% to 1%, 0.004% to 1%, 0.005% to 1%, 0.006% to 1%, 0.008% to 1%, 0.01% to 1%, 0.02% to 1%, 0.04% to 1%, 0.05% to 1%, 0.06% to 1%, 0.08% to 1%, 0.1% to 1%, 0.2% to 1%, 0.4% to 1%, 0.5% to 1%, 0.6% to 1%, 0.8% to 1%, 0.0005% to 0.8%, 0.0005% to 0.6%, based on the total weight of the etchant composition. 0.0005%~0.5%, 0.0005%~0.4%, 0.0005%~0.2%, 0.0005%~0.1%, 0.0005%~0.08%, 0.0005%~0.06%, 0.0005%~0.05%, 0.0005%~0.04%, 0.0005%~0.02%, 0.0005 % to 0.01%, 0.0005% to 0.008%, 0.0005% to 0.006%, 0.0005% to 0.005%, 0.0005% to 0.004%, 0.0005% to 0.002%, 0.0005% to 0.001%, or 0.0005% to 0.0008% of silicon-containing compounds.

[0045] The etchant composition may comprise 0.1 wt. % to 10 wt. % of the silicon-containing compound, based on the total weight of the etchant composition. For example, in some embodiments, the etchant composition 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%, 0.1% to 1%, 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%, 9% to 10%, or any combination thereof.

[0046] In some embodiments, one or more components have the formula: Compound TIFF2025534745000002.tif32170 or any derivative thereof, During the ceremony: A is aryl; Each R 1 are independently hydrogen, hydroxyl, hydroxy, alkyl, alkylamino, phenyl, benzyl, alkoxy, phenoxy, or cycloalkyl; x is 0 or 1; y is 0 or 1 to 5; y' is 0 or 1 to 5; z is 1 to 3; m is 1 to 3; w is 0 or 1 to 4.

[0047] In some embodiments, each R 1 are independently hydrogen, hydroxyl, hydroxy, C1-C 20 Alkyl, C1-C 20 Alkylamino, phenyl, benzyl, C1-C 20 It is alkoxy, phenoxy, or C3-C8 cycloalkyl.

[0048] In some embodiments, each R 1 are the same. In some embodiments, at least one R 1 In some embodiments, each R 1 is different.

[0049] In some embodiments, y and y' are the same. In some embodiments, y and y' are different.

[0050] In some embodiments, m+z is equal to 4.

[0051] In some embodiments, one or more components have the formula: Compound TIFF2025534745000003.tif32170 or any derivative thereof, During the ceremony: Each R 2are independently hydrogen, hydroxyl, hydroxy, alkyl, alkylamino, phenyl, benzyl, alkoxy, phenoxy, or cycloalkyl; -M- is -NH- or -O-.

[0052] In some embodiments, each R 2 are independently hydrogen, hydroxyl, hydroxy, C1-C 20 Alkyl, C1-C 20 Alkylamino, phenyl, benzyl, C1-C 20 It is alkoxy, phenoxy, or C3-C8 cycloalkyl.

[0053] In some embodiments, each R 2 are the same. In some embodiments, at least one R 2 In some embodiments, each R 2 is different.

[0054] In some embodiments, one or more components have the formula: Compound TIFF2025534745000004.tif48170 or any derivative thereof, During the ceremony: Q is O or N; R 3 ~R 8 are each independently hydrogen, alkyl, alkoxy, alkenyl, cycloalkyl, aminoalkyl, aryl, alkylcarbonyl, alkylcarbonyloxy, or cyanoalkyl; z is 0 or 1, provided that when z is 0, R 3 ~R 7 At least two of the are alkoxy.

[0055] In some embodiments, R 3 ~R 8 are each independently hydrogen, C1 to C 20 Alkyl, C1-C 20 Alkoxy, C2-C 20Alkenyl, C3-C 20 Cycloalkyl, C1-C 20 Aminoalkyl, C6-C 20 Aryl, C1-C 20 Alkylcarbonyl, C1-C 20 Alkylcarbonyloxy or C1-C 10 It is a cyanoalkyl.

[0056] In some embodiments, one or more of the components may be alkylbenzene sulfonic acids; alkyldiphenyloxide disulf ... x ] n (OR) m wherein n is 1 to 3, m is 1 to 3, x is 0 or 1 to 3, m+n=4, and each R is independently hydrogen or alkyl; Compound TIFF2025534745000005.tif69170 or any derivative thereof (In the formula: R is alkyl (e.g., C1-C4 alkyl); or any combination thereof. The alkylbenzene sulfonic acid may be linear or branched. The alkyldiphenyloxide disulfonic acid may be C8-C 16 The alkylbenzene sulfonic acid may be an alkyldiphenyloxide disulfonic acid. 12 It may be an alkyldiphenyloxide disulfonic acid. In some embodiments, the one or more components include at least one of dodecylbenzenesulfonic acid, 4-octylbenzenesulfonic acid, hexyldiphenyloxide disulfonic acid, tetrapropyl-(sulfophenoxy)-benzenesulfonic acid, or any combination thereof.

[0057] In some embodiments, one or more of the components may include a pyridine compound or any derivative thereof. In some embodiments, the pyridine compound includes 4-(3-phenylpropyl)pyridine.

[0058] 1 is a flowchart of a method 100 for selectively etching silicon nitride, according to some embodiments. As shown in FIG. 1, in some embodiments, the method 100 may include at least one of the following steps: obtaining a substrate 102; obtaining an oxide removal composition 104; obtaining an etchant composition 106; contacting the substrate with the oxide removal composition 108; contacting the substrate with the etchant composition 110; or any combination thereof.

[0059] In step 102, in some embodiments, a substrate is obtained. The substrate may include at least one of silicon nitride, silicon oxide, polysilicon, or any combination thereof. In some embodiments, the substrate includes a surface including silicon nitride. In some embodiments, the substrate includes a surface including silicon oxide. In some embodiments, the substrate includes a surface including polysilicon. The substrate may include other materials, including surfaces including other materials. The substrate may contain other materials useful in microelectronic devices, such as one or more of insulating materials, barrier layers, conductive materials, semiconducting materials, metal silicides, or materials useful in microelectronic device processing (e.g., photoresist, masks, among others). Examples of substrates include those having a surface including at least one of silicon nitride, thermal oxide (ThOx), PETEOS (oxide deposited using plasma-enhanced tetraethyl orthosilicate), polysilicon, or any combination thereof.

[0060] In some embodiments, the substrate comprises alternating thin film layers of silicon nitride. In some embodiments, the substrate comprises layers of silicon nitride layers alternating with at least one of layers of silicon oxide, layers of polysilicon, layers of conductive metal silicide, layers of dielectric (such as zirconium oxide or aluminum oxide), or any combination thereof. Prior to contact with the etchant composition, the substrate comprises alternating layers of silicon nitride disposed within openings between high aspect ratio silicon oxide structures.

[0061] In step 104, in some embodiments, an oxide removal composition is obtained. The oxide removal composition may include hydrogen fluoride (HF). In some embodiments, the hydrogen fluoride is present in a dilute hydrogen fluoride solution.

[0062] In step 106, in some embodiments, an etchant composition is obtained. Any of the etchant compositions disclosed herein can be used. For example, in some embodiments, the etchant composition includes at least 60 wt. % phosphoric acid, based on the total weight of the composition; at least 5 wt. % water, based on the total weight of the composition; and 2 wt. % or less of a metal oxidizing agent, based on the total weight of the composition. It will be understood that other etchant compositions disclosed herein may be used without departing from the present disclosure.

[0063] In step 108, in some embodiments, the substrate is contacted with an oxide removal composition. The oxide removal composition can be useful for removing surface oxides from the substrate, particularly from silicon nitride surfaces. That is, in some embodiments, a thin oxide surface is present on the silicon nitride surface or film. The presence of surface oxides can reduce the etch rate of silicon nitride. Therefore, in some embodiments, the substrate is contacted with the oxide removal composition. As described above, in some embodiments, the oxide removal composition comprises hydrogen fluoride. In some embodiments, the oxide removal composition comprises dilute hydrogen fluoride. After contacting the substrate with the oxide removal composition, excess oxide removal composition and other materials may be rinsed, washed, or otherwise removed from the surface using water (e.g., deionized water) at a temperature ranging from 20°C to 90°C, or any range or subrange therebetween, followed by drying (e.g., spin drying, contact with nitrogen (N), air drying, etc.).

[0064] In step 110, in some embodiments, the substrate is contacted with the etchant composition. Contacting may include applying the etchant composition to the surface by at least one of spraying the etchant composition onto the surface; immersing the substrate in the etchant composition (in a static or dynamic volume of the etchant composition); contacting the surface with another material (e.g., a pad absorbed with the etchant composition, or a fibrous adsorbent applicator element); contacting the substrate with a volume of the etchant composition in a circulating pool; immersing the substrate in the etchant composition, or any combination thereof, among other techniques for bringing the etchant composition into removal contact with the surface of the silicon-containing microelectronic substrate. Application may be in a batch or single-wafer system for dynamic or static cleaning.

[0065] The selective etching of silicon nitride using the etchant composition may proceed in the presence of silicon oxide and polysilicon, as described above. In addition to silicon oxide and polysilicon, the selective etching of silicon nitride using the etchant composition may proceed in the presence of other materials while maintaining selectivity to silicon nitride. Examples of these other materials include, but are not limited to, at least one of a conductive material, a semiconductor material, an insulating material, a processing material, or any combination thereof. In some embodiments, a metal silicide is present during the selective etching of silicon nitride. In some embodiments, a metal silicide is present but not exposed during the selective etching of silicon nitride.

[0066] The contacting conditions may include at least one of duration, temperature, or any combination thereof. The duration should be sufficient to selectively remove silicon nitride. The exposure time to the etchant composition and the temperature of the etchant composition can be selected based on the desired amount of silicon nitride removed from the surface of the substrate. The duration of contact should balance process control and quality with the process efficiency and throughput of the etching process and semiconductor fabrication line. Examples of suitable durations can range from 5 minutes to 300 minutes, or any range or subrange therebetween, e.g., 10 minutes to 60 minutes. Examples of suitable temperatures are temperatures in the range of 100°C to 250°C (e.g., 100°C to 180°C, 150°C to 180°C), or any range or subrange therebetween. Such contacting times and temperatures are exemplary, and other suitable contacting time and temperature conditions may be used herein without departing from the present disclosure.

[0067] By contacting a substrate with the etchant composition, the etchant composition may passivate at least one of a surface comprising polysilicon, a surface comprising silicon oxide, or any combination thereof. In some embodiments, passivating a surface includes modifying the surface to reduce its reactivity, for example, in the presence of a substance that etches silicon nitride. In some embodiments, the metal oxidizer is configured to modify or alter a surface comprising polysilicon, if present, to reduce its reactivity. In some embodiments, the metal oxidizer is configured to modify or alter a surface comprising silicon oxide, if present, to reduce its reactivity. In some embodiments, the etchant composition passivates surfaces other than silicon nitride.

[0068] The etchant composition may exhibit a selectivity of silicon nitride over polysilicon of at least 150, at least 200, at least 500, at least 1000, at least 2000, at least 4000, or more. In some embodiments, for example, the etchant composition exhibits a selectivity of silicon nitride over polysilicon of 10:1 to 7000:1, or any range or subrange therebetween. The etchant composition may exhibit a selectivity of silicon nitride over silicon oxide of at least 150, at least 200, at least 500, at least 1000, at least 2000, at least 4000, or more. In some embodiments, for example, the etchant composition exhibits a selectivity of silicon nitride over silicon oxide of 10:1 to 7000:1, or any range or subrange therebetween. In some embodiments, the selectivity of the etchant composition for silicon nitride relative to polysilicon and silicon oxide is the same or similar. In some embodiments, the selectivity of the etchant composition for silicon nitride relative to polysilicon and silicon oxide is different.

[0069] After contacting the substrate with the etchant composition, excess etchant composition and other materials may be rinsed, washed, or otherwise removed from the surface using water (e.g., deionized water) at a temperature ranging from 20°C to 90°C, or any range or subrange therebetween, followed by drying (e.g., spin drying, contact with nitrogen (N), air drying, etc.).

[0070] 2 is a schematic diagram of a method 200 for selectively etching silicon nitride, according to some embodiments. As shown in FIG. 2, in some embodiments, a substrate 202 includes silicon nitride 204, polysilicon 206, and silicon oxide 208. The substrate 202 also includes a surface oxide 210. In step 220, the surface oxide 210 is removed. In step 240, the polysilicon 206 is passivated and the silicon nitride 204 is etched without etching the polysilicon 206 (e.g., passivated polysilicon) or without etching at least less than 5% of the surface of the polysilicon 206.

[0071] 3 depicts a process flow diagram showing a structure having polysilicon at the bottom of the via, but also containing silicon oxide and silicon nitride surfaces. A combined passivation and etching process according to the present disclosure involves incorporating cerium sulfate, Ce(IV)SO4, into an etchant composition such as Entegris PlanarEX 2155.

[0072] FIG. 3 is a flowchart of a method 300 for forming an etchant composition according to some embodiments. As shown in FIG. 3, in some embodiments, the method 300 for forming an etchant composition includes at least one of the following steps: step 302 of obtaining a metal oxidant, phosphoric acid, and water; step 304 of contacting the metal oxidant, phosphoric acid, and water to form an etchant composition; or any combination thereof. In some embodiments, the contacting is performed while heating to a temperature in the range of 20° C. to 200° C., or any range or subrange therebetween. In some embodiments, the contacting includes mixing, combining, adding, or otherwise bringing into close proximity or direct proximity to form the etchant composition. It will be understood that any one or more components disclosed herein may be included in the etchant composition without departing from the present disclosure.

[0073] Example 1 Base Formulation A base formulation was prepared containing approximately 82 wt. % phosphoric acid, approximately 14 wt. % water, approximately 4 wt. % 3-aminopropylsilanetriol, and approximately 0.1 wt. % tetramethylammonium silicate. The weight percentages are based on the total weight of the base formulation.

[0074] Example 2 Comparative formulation (no metal oxidizer) The base formulation of Example 1 was exposed to blanket silicon nitride (SiN) and phosphorus-doped polysilicon films at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) and phosphorus-doped polysilicon films were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below.

[0075] Example 3 Formulation A Approximately 0.1 wt. % of phosphomolybdic acid hydrate was added to the base formulation of Example 1 to form Formulation A. Formulation A was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation.

[0076] Example 4 Formulation B Approximately 0.1 wt. % silicomolybdic acid was added to the base formulation of Example 1 to form Formulation B. Formulation B was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation.

[0077] Example 5 Formulation C Approximately 0.1 wt. % molybdenum (VI) oxide was added to the base formulation of Example 1 to form Formulation C. Formulation C was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation.

[0078] Example 6 Formulation D Approximately 0.1 wt. % cerium (IV) sulfate was added to the base formulation of Example 1 to form Formulation D. Formulation D was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation.

[0079] Example 7 Formulation E Approximately 0.05% by weight of cerium (IV) sulfate was added to the base formulation of Example 1 to form Formulation E. Formulation E was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation.

[0080] Example 8 Formulation F Approximately 0.05 wt. % La2O3 was added to the base formulation of Example 1 to form Formulation F. Formulation F was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation.

[0081] Example 9 Formulation G Approximately 0.25 wt. % nitric acid was added to the base formulation of Example 1 to form Formulation G. Formulation G was exposed to a blanket silicon nitride (SiN) film and a phosphorus-doped polysilicon film at a temperature of 160°C. The thickness changes of the blanket silicon nitride (SiN) film and the phosphorus-doped polysilicon film were measured by spectroscopic ellipsometry. The SiN etch rate and polysilicon etch rate were calculated from the measured thickness changes over periods of 10 and 120 minutes, respectively. The results are summarized in Table 1 below. Weight percentages are based on the total weight of the base formulation. TIFF2025534745000006.tif71170

[0082] Aspects Various aspects are described below. It should be understood that any one or more of the features listed in the following aspects can be combined with any one or more of the other aspects.

[0083] Embodiment 1. An etchant composition comprising: at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition; At least 1 wt. % water, based on the total weight of the etchant composition; and 2% by weight or less of a metal oxidizer based on the total weight of the etchant composition Including, The etchant composition, wherein the metal oxidant is configured to modify the polysilicon-containing surface, if present, to reduce the reactivity of the polysilicon-containing surface with phosphoric acid.

[0084] Aspect 2. The etching solution composition according to Aspect 1, comprising 80% to 95% by weight of phosphoric acid based on the total weight of the etching solution composition.

[0085] Aspect 3 The etching solution composition according to any one of Aspects 1 and 2, comprising 1 wt % to 25 wt % of water based on the total weight of the etching solution composition.

[0086] Aspect 4. The etching solution composition according to any one of Aspects 1 to 3, comprising 0.001 wt % to 1 wt % of the metal oxidizing agent, based on the total weight of the etching solution composition.

[0087] Aspect 5. The etching solution composition according to any one of Aspects 1 to 4, comprising 0.001 wt % to 0.1 wt % of a metal oxidizing agent, based on the total weight of the etching solution composition.

[0088] Embodiment 6. The etching solution composition of any one of embodiments 1-5, wherein the metal oxidizer comprises at least one cation of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, or any combination thereof.

[0089] Aspect 7. The metal oxidant is Ce +3 , Ce +4 , V +2 , V +3 , V +4 , V +5 , Mo +2 , Mo +3 , Mo +4 , Mo +5 , Mo +6 or any combination thereof.

[0090] Embodiment 8. The etching solution composition according to any one of embodiments 1 to 7, wherein the metal oxidizing agent is a dissolution product of a metal oxidizing agent.

[0091] Embodiment 9. The etching solution composition of embodiment 8, wherein the metal oxidizing agent comprises at least one of titanium(IV) oxysulfate, titanium(IV) sulfate hydrate, phosphomolybdic acid hydrate, silicomolybdic acid, molybdenum(VI) oxide, molybdic acid, lanthanum oxide, cerium(IV) sulfate, cerium ammonium nitrate, phosphotungstic acid, vanadium pentoxide, cobalt(III) acetylacetonate, or any combination thereof.

[0092] Embodiment 10. The etching solution composition of any one of embodiments 1-8, further comprising at least one of a fluoride compound, a silicon-containing compound, an alkylbenzene sulfonic acid, an alkyldiphenyloxide disulfonic acid, a pyridine compound, or any combination thereof.

[0093] Embodiment 11. The etchant composition of any one of Embodiments 1-9, exhibiting a selectivity of silicon nitride to polysilicon in the range of 10:1 to 7000:1.

[0094] Embodiment 12. Obtaining a substrate, a surface comprising silicon nitride; a surface comprising silicon oxide, and including polysilicon-containing surfaces Obtaining a substrate; Obtaining an etchant composition, comprising: at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition; At least 1 wt. % water, based on the total weight of the etchant composition; and 2% by weight or less of a metal oxidizer based on the total weight of the etchant composition obtaining an etching solution composition comprising: contacting the substrate with an etchant composition; Including, the etchant composition removes at least a portion of the surface comprising silicon nitride; The method, wherein the etchant composition removes less than 5% of the surface comprising polysilicon.

[0095] Embodiment 13. The method of embodiment 12, wherein the etchant composition comprises 80% to 95% by weight of phosphoric acid, based on the total weight of the etchant composition.

[0096] Embodiment 14. The method of any one of Embodiments 12-13, wherein the etchant composition comprises 1 wt % to 25 wt % water, based on the total weight of the etchant composition.

[0097] Embodiment 15. The method of any one of embodiments 12 to 14, wherein the etchant composition comprises 0.001 wt % to 1 wt % of the metal oxidant, based on the total weight of the etchant composition.

[0098] Embodiment 16. The method of any one of embodiments 12 to 15, wherein the etchant composition comprises 0.001 wt % to 0.1 wt % of the metal oxidizing agent, based on the total weight of the etchant composition.

[0099] Embodiment 17. The method of any one of embodiments 12-16, wherein the metal oxidizer comprises at least one cation of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, or any combination thereof.

[0100] Embodiment 18. The method of any one of embodiments 12-17, wherein the etchant composition further comprises at least one of a fluoride compound, a silicon-containing compound, an alkylbenzene sulfonic acid, an alkyldiphenyloxide disulfonic acid, a pyridine compound, or any combination thereof.

[0101] Embodiment 19. The method of any one of embodiments 12 to 18, wherein the etchant composition exhibits a selectivity of silicon nitride to polysilicon in the range of 10:1 to 7000:1.

[0102] 20. A method comprising: Obtaining phosphoric acid; Getting water and obtaining a metal oxidant; and contacting phosphoric acid, water, and a metal oxidizing agent to form an etchant composition, wherein the etchant composition comprises: at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition; At least 1 wt. % water, based on the total weight of the etchant composition; and containing 2 wt. % or less of a metal oxidizer based on the total weight of the etching solution composition; The method, wherein the metal oxidizing agent is configured to modify the polysilicon-containing surface, if present, to reduce the reactivity of the polysilicon-containing surface with phosphoric acid.

Claims

1. An etchant composition comprising: at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition; At least 1 wt. % water, based on the total weight of the etchant composition; and 2 wt. % or less of a metal oxidizer, based on the total weight of the etchant composition, a metal oxidizing agent configured to modify a polysilicon-containing surface, if present, to reduce the reactivity of the polysilicon-containing surface with phosphoric acid; An etching solution composition comprising:

2. 10. The etching solution composition of claim 1, comprising 80% to 95% by weight of phosphoric acid, based on the total weight of the etching solution composition.

3. 10. The etching solution composition of claim 1, comprising 1 wt % to 25 wt % water, based on the total weight of the etching solution composition.

4. 10. The etching solution composition of claim 1, comprising 0.001 wt % to 1 wt % of the metal oxidizing agent, based on the total weight of the etching solution composition.

5. 10. The etching solution composition of claim 1, comprising 0.001 wt % to 0.1 wt % of the metal oxidizing agent, based on the total weight of the etching solution composition.

6. 2. The etchant composition of claim 1, wherein the metal oxidizer comprises at least one cation of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, or any combination thereof.

7. The metal oxidizing agent is Ce ＋３ , Ce ＋４ , V ＋２ , V ＋３ , V ＋４ , V ＋５ , Mo ＋２ , Mo ＋３ , Mo ＋４ , Mo ＋５ , Mo ＋６ 10. The etching solution composition of claim 1, wherein the etchant composition is at least one of:

8. 10. The etching solution composition of claim 1, wherein the metal oxidizer is a dissolution product of a metal oxidizer.

9. 9. The etchant composition of claim 8, wherein the metal oxidizer comprises at least one of titanium (IV) oxysulfate, titanium (IV) sulfate hydrate, phosphomolybdic acid hydrate, silicomolybdic acid, molybdenum (VI) oxide, molybdic acid, lanthanum oxide, cerium (IV) sulfate, cerium ammonium nitrate, phosphotungstic acid, vanadium pentoxide, cobalt (III) acetylacetonate, or any combination thereof.

10. 10. The etchant composition of claim 1, further comprising at least one of a fluoride compound, a silicon-containing compound, an alkylbenzene sulfonic acid, an alkyldiphenyloxide disulfonic acid, a pyridine compound, or any combination thereof.

11. 10. The etchant composition of claim 1, which exhibits a selectivity of silicon nitride to polysilicon in the range of 10:1 to 7000:

1.

12. 1. A method comprising: Obtaining a substrate, a surface comprising silicon nitride; a surface comprising silicon oxide, and Polysilicon-containing surfaces obtaining a substrate comprising Obtaining an etchant composition, comprising: at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition; At least 1 wt. % water, based on the total weight of the etchant composition; and 2% by weight or less of a metal oxidizer based on the total weight of the etchant composition obtaining an etching solution composition comprising: contacting the substrate with an etchant composition; Including, the etchant composition removes at least a portion of the surface comprising silicon nitride; the etchant composition removes less than 5% of the surface containing polysilicon; method.

13. 13. The method of claim 12, wherein the etchant composition comprises 80% to 95% by weight of phosphoric acid, based on the total weight of the etchant composition.

14. 13. The method of claim 12, wherein the etchant composition comprises 1 wt % to 25 wt % water, based on the total weight of the etchant composition.

15. 13. The method of claim 12, wherein the etchant composition comprises 0.001 wt % to 1 wt % of the metal oxidizing agent, based on the total weight of the etchant composition.

16. 13. The method of claim 12, wherein the etchant composition comprises 0.001 wt % to 0.1 wt % of the metal oxidizing agent, based on the total weight of the etchant composition.

17. 13. The method of claim 12, wherein the metal oxidizer comprises at least one cation of Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Re, Os, Ir, Pt, Au, Hg, Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr, Rf, Db, Sg, Bh, Hs, Mt, Ds, Rg, Cn, or any combination thereof.

18. 13. The method of claim 12, wherein the etchant composition further comprises at least one of a fluoride compound, a silicon-containing compound, an alkylbenzene sulfonic acid, an alkyldiphenyloxide disulfonic acid, a pyridine compound, or any combination thereof.

19. 13. The method of claim 12, wherein the etchant composition exhibits a selectivity of silicon nitride to polysilicon in the range of 10:1 to 7000:

1.

20. 1. A method comprising: Obtaining phosphoric acid; Getting water and obtaining a metal oxidant; and contacting phosphoric acid, water, and a metal oxidizing agent to form an etchant composition, wherein the etchant composition comprises: at least 60 wt. % phosphoric acid, based on the total weight of the etchant composition; At least 1 wt. % water, based on the total weight of the etchant composition; and 2 wt. % or less of a metal oxidizer, based on the total weight of the etchant composition, a metal oxidizing agent configured to modify a polysilicon-containing surface, if present, to reduce the reactivity of the polysilicon-containing surface with phosphoric acid; A method comprising:

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