Wet Etch Formulations and Related Methods

Abstract

Wet etching compositions and related methods are provided herein. A wet etching composition for molybdenum contains phosphoric acid, acetic acid, nitric acid, and MoO. x Additives may be included to reduce the oxidation rate of the layer, and may be present in an amount of 0.01% to 5% by weight, based on the total weight of the wet etching composition.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to the field of wet etching formulations and related methods. [Background technology]

[0002] 3D NAND structures contain molybdenum layers that must be selectively removed by etching. Removing molybdenum in recesses in 3D NAND structures without removing non-molybdenum materials (e.g., tetraethyl orthosilicate (TEOS) and aluminum oxide) remains challenging. Also, lack of uniformity in etch depth remains a challenge, resulting in molybdenum layers etched to varying depths.

[0003] overview Some embodiments relate to a wet etching composition for molybdenum materials. In some embodiments, the wet etching composition comprises a mixture of phosphoric acid, acetic acid, nitric acid, MoO x At least one of, or any combination of, additives for reducing the oxidation rate of the layer, hi some embodiments, the additives are present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition.

[0004] Some embodiments relate to a method for etching a molybdenum material. In some embodiments, the method includes one or more of the following steps: obtaining a structure including a plurality of recesses and a molybdenum material disposed in the plurality of recesses, and contacting the structure with a wet etching composition to remove at least a portion of the molybdenum material. In some embodiments, the wet etching composition includes a compound selected from the group consisting of phosphoric acid, acetic acid, nitric acid, MoO x At least one of, or any combination of, additives for reducing the oxidation rate of the layer, hi some embodiments, the additives are present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition.

[0005]

[0005] Some embodiments of the present disclosure will now be described, by way of example only, with reference to the accompanying drawings. With specific reference to the drawings in detail, it is emphasized that the embodiments shown therein are exemplary and are intended as an illustrative discussion of the disclosed embodiments. In this regard, the description made in the drawings will make apparent to those skilled in the art how the disclosed embodiments may be practiced. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a process flow diagram illustrating a 3D NAND structure with tetraethyl orthosilicate (TEOS), aluminum oxide, and molybdenum, according to some embodiments. [Figure 2] 1 is an illustration of the results of a method for removing molybdenum, in which a 3D NAND structure having molybdenum is subjected to a wet etching composition according to some embodiments. [Figure 3] 1 is a flowchart of a method for removing molybdenum, in which a 3D NAND structure having molybdenum is subjected to a wet etching composition according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0007] 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. Detailed embodiments of the present disclosure are disclosed herein. However, it should be understood that the disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms. Moreover, the examples given with respect to various embodiments of the present disclosure are intended to be illustrative and not limiting.

[0008]

[0010] All prior patents and publications referenced herein are incorporated by reference in their entirety.

[0009] Throughout the specification and claims, the following terms have the meanings explicitly associated therewith unless the context clearly dictates otherwise. As used herein, the phrases "in one embodiment," "in an embodiment," and "in some embodiments" do not necessarily refer to the same embodiment or embodiments, but may. Furthermore, as used herein, the phrases "in another embodiment" and "in some other embodiments" 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.

[0010] As used herein, the term "based on" is not exclusive and allows for based on additional unrecited factors unless the context clearly dictates otherwise. Additionally, throughout the specification, the meanings of "a," "an," and "the" include plural references. The meaning of "in" includes "in" and "on."

[0011] Some embodiments relate to wet etching formulations and related methods for selectively removing molybdenum materials from microelectronic devices, such as, but not limited to, 3D NAND structures. Selective removal of molybdenum can improve the uniformity of feature depth across the 3D NAND structure, maintain yield, and prevent variations in chemical composition and electrical performance. In some embodiments, the wet etching composition comprises a mixture of phosphoric acid (H3PO4), acetic acid (CH3COOH), nitric acid (HNO3), and molybdenum oxide (MoO x The wet etching composition may include an additive to reduce the oxidation rate of the MoO layer. In some embodiments, the additive may be present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition ... x The x in the (molybdenum oxide) layer is 1 to 5.

[0012] The additive of the wet etching composition may be at least one of a nitrogen-containing salt, a nitrogen-containing acid, a nitrogen-containing compound, a phosphorus-containing acid, a phosphorus-containing oxide, and a phosphorus-containing salt, or any combination thereof. In some embodiments, the wet etching composition may be at least one of an ammonium salt, an organic chloride salt, a phosphonic acid, a phosphine oxide, an ammonium salt of phosphoric acid, a benzotriazole, and a citric acid, a quaternary ammonium salt, or any combination thereof. In some embodiments, the quaternary ammonium salt comprises a nitrogen-containing salt having four (quaternary) bonds. In some embodiments, the additive 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 additive can be at least one of n-dodecylphosphonic acid and benzylphosphonic acid, or any combination thereof. In some embodiments, the additive can be at least one of trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphine oxide, triethylamine phosphate, ammonium phosphate monobasic, and 5-methyl-1H-benzotriazole, or any combination thereof.

[0013]

[0015] The wet etching composition can have 1% to 20% by weight phosphoric acid, or any range or subdivision therebetween, based on the total weight of the wet etching composition. For example, in some embodiments, the weight percent of phosphoric acid, based on the total weight of the wet etching composition, can be 1% to 15%, 1% to 10%, or 5% to 20%. In some embodiments, the weight percent of phosphoric acid, based on the total weight of the wet etching composition, can be 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%. In some embodiments, the weight percentage of phosphoric acid based on the total weight of the wet etching composition can be between 1% and 19%, between 1% and 18%, between 1% and 17%, between 1% and 16%, between 1% and 15%, between 1% and 14%, between 1% and 13%, between 1% and 12%, between 1% and 11%, between 1% and 10%, between 1% and 9%, between 1% and 8%, between 1% and 7%, between 1% and 6%, between 1% and 5%, between 1% and 4%, between 1% and 3%, or between 1% and 2%.

[0014] The wet etching composition can have 50% to 90% by weight acetic acid, or any range or subdivision therebetween, based on the total weight of the wet etching composition. For example, in some embodiments, the weight percent of acetic acid, based on the total weight of the wet etching composition, can be 55% to 90%, 60% to 90%, 65% to 90%, 70% to 90%, 75% to 90%, 80% to 90%, or 85% to 90%. In some embodiments, the weight percentage of acetic acid based on the total weight of the wet etching composition is between 51% and 90%, 52% and 90%, 53% and 90%, 54% and 90%, 55% and 90%, 56% and 90%, 57% and 90%, 58% and 90%, 59% and 90%, 60% and 90%, 61% and 90%, 62% and 90%, 63% and 90%, 64% and 90%, 65% and 90%, 66% and 90%, 67% and 90%, 68% and 90%, %, 69% to 90%, 70% to 90%, 71% to 90%, 72% to 90%, 73% to 90%, 74% to 90%, 75% to 90%, 76% to 90%, 77% to 90%, 78% to 90%, 79% to 90%, 80% to 90%, 80% to 95%, 81% to 90%, 82% to 90%, 83% to 90%, 84% to 90%, 85% to 90%, 86% to 90%, 87% to 90%, 88% to 90%, or 89 to 90%. In some embodiments, the weight percentage of acetic acid based on the total weight of the wet etching composition is between 50% and 89%, 50% and 88%, 50% and 87%, 50% and 86%, 50% and 85%, 50% and 84%, 50% and 83%, 50% and 82%, 50% and 81%, 50% and 80%, 50% and 79%, 50% and 78%, 50% and 77%, 50% and 76%, 50% and 75%, 50% and 74%, 50% and 73%, 50% and 85%, 50% and 86%, 50% and 87%, 50% and 88%, 50% and 89%, 50% and 90%, 50% and 91%, 50% and 92%, 50% and 93%, 50% and 94%, 50% and 95%, 50% and 96%, 50% and 97%, 50% and 98%, 50% and 9 ... The range may be % 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%.

[0015] The wet etching composition can have 0.1% to 20% by weight nitric acid, or any range or subdivision therebetween, based on the total weight of the wet etching composition. For example, in some embodiments, the weight percent of nitric acid, based on the total weight of the wet etching composition, can be 1% to 20%, 1% to 15%, 1% to 10%, or 5% to 20%. In some embodiments, the weight percentage of nitric acid based on the total weight of the wet etching composition can be between 1% and 20%, 2% and 20%, 3% and 20%, 4% and 20%, 5% and 20%, 6% and 20%, 7% and 20%, 8% and 20%, 9% and 20%, 10% and 20%, 11% and 20%, 12% and 20%, 13% and 20%, 14% and 20%, 15% and 20%, 16% and 20%, 17% and 20%, 18% and 20%, or 19% and 20%. In some embodiments, the weight percentage of nitric acid based on the total weight of the wet etching composition can be between 0.1% and 19%, between 0.1% and 18%, between 0.1% and 17%, between 0.1% and 16%, between 0.1% and 15%, between 0.1% and 14%, between 0.1% and 13%, between 0.1% and 12%, between 0.1% and 11%, between 0.1% and 10%, between 0.1% and 9%, between 0.1% and 8%, between 0.1% and 7%, between 0.1% and 6%, between 0.1% and 5%, between 0.1% and 4%, between 0.1% and 3%, between 0.1% and 2%, or between 0.1% and 1%. In some embodiments, the weight percentage of nitric acid based on the total weight of the wet etching composition can be 0.1% to 5%, 0.5% to 5%, 1% to 5%, 1.5% to 5%, 2% to 5%, 2.5% to 5%, 3% to 5%, 3.5% to 5%, 4% to 5%, or 4.5% to 5%. In some embodiments, the weight percentage of nitric acid based on the total weight of the wet etching composition can be 0.1% to 5%, 0.1% to 4.5%, 0.1% to 4%, 0.1% to 3.5%, 0.1% to 3%, 0.1% to 2.5%, 0.1% to 2%, 0.1% to 1.5%, 0.1% to 1%, or 0.1% to 0.5%.

[0016] The wet etching composition may further include citric acid in an amount of 0.1% to 10% by weight, or any range or subdivision therebetween, based on the total weight of the wet etching composition. For example, in some embodiments, the weight percentage of citric acid based on the total weight of the wet etching composition may be 1% to 10%, 1% to 5%, 1% to 2.5%, or 2.5% to 5%. In some embodiments, the weight percentage of citric acid based on the total weight of the wet etching composition may be 0.1% to 5%, 0.5% to 5%, 1% to 5%, 1.5% to 5%, 2% to 5%, 2.5% to 5%, 3% to 5%, 3.5% to 5%, 4% to 5%, or 4.5% to 5%. In some embodiments, the weight percentage of citric acid based on the total weight of the wet etching composition can be between 0.1% and 5%, between 0.1% and 4.5%, between 0.1% and 4%, between 0.1% and 3.5%, between 0.1% and 3%, between 0.1% and 2.5%, between 0.1% and 2%, between 0.1% and 1.5%, between 0.1% and 1%, or between 0.1% and 0.5%.

[0017] The wet etching composition may be free of tungsten compounds, hi some embodiments, the tungsten compound comprises at least one of tungsten oxide, tungsten trioxide, tungstic acid, sodium tungstate, ammonium paratungstate, tungsten carbide, and ditungsten carbide, or any combination thereof.

[0018]

[0020] Some embodiments relate to wet etching formulations and related methods for selectively removing molybdenum from three-dimensional NAND structures. In some embodiments, the method may include obtaining a structure including a plurality of recesses and a molybdenum material disposed in the plurality of recesses, and contacting the structure with a wet etching composition to remove at least a portion of the molybdenum material. In some embodiments, the structure may have a plurality of recesses and a molybdenum material disposed in the plurality of recesses. In some embodiments, the wet etching composition may include a mixture of phosphoric acid, acetic acid, nitric acid, and MoO. xAn additive may be included to reduce the oxidation rate of the layer. In some embodiments, the additive may be present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition. In some embodiments, MoO x The x in the (molybdenum oxide) layer is 1 to 5.

[0019] 1 is a diagram of a process flow 100 showing a 3D NAND structure comprising tetraethyl orthosilicate (TEOS) 102, aluminum oxide 112, and molybdenum 104. The first step in removing the molybdenum 104 may be to oxidize 106 the molybdenum 104 to form a molybdenum oxide layer 108. After oxidation 106, the molybdenum oxide layer 108 may be etched 110. After etching 110, the recesses in the 3D NAND structure may be uniform.

[0020] FIG. 2 shows a diagram of the results 200 of a method for removing molybdenum 104. As shown in FIGS. 1-3, a three-dimensional NAND structure having molybdenum 104 is subjected to a wet etching composition 210. In some embodiments, the wet etching composition 210 is a PAN composition (phosphoric acid, acetic acid, and nitric acid). In some embodiments, the PAN composition may include an additive to reduce the oxidation rate of the molybdenum oxide layer 108. In some embodiments, the additive may be present in an amount of 0.01% to 5% by weight, based on the total weight of the wet etching composition 210.

[0021] FIG. 3 shows a flowchart of a method 300 for removing molybdenum. As shown in FIGS. 1-3, a three-dimensional NAND structure having molybdenum 104 is subjected to a wet etching composition 210. In some embodiments, the method 300 can include obtaining a structure including a plurality of recesses and a molybdenum material disposed in the plurality of recesses 310, and contacting the structure with a wet etching composition to remove at least a portion of the molybdenum material 320. In some embodiments, the structure can be a three-dimensional NAND structure. In some embodiments, the wet etching composition 210 can be phosphoric acid, acetic acid, nitric acid, and an additive for reducing the oxidation rate of the molybdenum oxide layer. In some embodiments, the additive can be present in an amount of 0.01% to 5% by weight, based on the total weight of the wet etching composition.

[0022] Example 1 A variety of wet etching compositions were prepared and their performance compared to a control composition. All samples were prepared using nitric acid, glacial acetic acid, phosphoric acid, water, and one or more additives, in that order.

[0023]

[0025] The wet etching composition of sample A contains 1 to 15 wt% phosphoric acid, 80 to 95 wt% acetic acid, 0.1 to 5 wt% nitric acid, 1 to 10 wt% water, and 1 wt% benzyldimethyldodecylammonium chloride. The wet etching composition of sample B contains 1 to 15 wt% phosphoric acid, 80 to 95 wt% acetic acid, 0.1 to 5 wt% nitric acid, 1 to 10 wt% water, and 0.05 wt% 1-dodecylpyridinium chloride. The wet etching composition of sample C contains 1 to 15 wt% phosphoric acid, 80 to 95 wt% acetic acid, 0.1 to 5 wt% nitric acid, 1 to 10 wt% water, and 0.05 wt% 1-methyl-3-N-octylimidazolium chloride. The wet etching composition of Sample D contains 1 to 15 wt% phosphoric acid, 80 to 95 wt% acetic acid, 0.1 to 5 wt% nitric acid, 1 to 10 wt% water, 0.01% to 5 wt% 1-dodecylpyridinium chloride, and 0.01% to 5 wt% citric acid.

[0024] The control composition contains 1-15 wt. % phosphoric acid, 80-95 wt. % acetic acid, 0.1-5 wt. % nitric acid, 1-10 wt. % water, and no additives. All weight percentages are based on the total weight of the composition unless otherwise specified herein.

[0025] Each composition was applied to a structure having a plurality of recesses and a molybdenum material disposed in the plurality of recesses at room temperature for a contact time after which the average depth of the molybdenum material at the top, center, and bottom of the structure was measured and reported in Table 1 below.

[0026] TIFF2026505185000002.tif64170

[0027] As shown, the addition of a small amount of additive to each wet etching composition significantly improved the average recess depth difference, and thus recess depth uniformity, of the molybdenum material compared to the control composition.

[0028]

[0030] Aspects Various embodiments are described below. It should be understood that one or more features mentioned in the following embodiments can be combined with one or more other embodiments.

[0029] Aspect 1 1. A wet etching composition for molybdenum comprising: phosphoric acid, acetic acid, nitric acid, and MoO x Additives to reduce the oxidation rate of the layer Including, A wet etching composition, wherein the additive is present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition.

[0030] Aspect 2 2. The wet etching composition of embodiment 1, wherein the additive comprises at least one of an ammonium salt, an organic chloride salt, a phosphonic acid, a phosphine oxide, an ammonium salt of phosphoric acid, a benzotriazole, and a citric acid, or any combination thereof.

[0031] Aspect 3 2. The wet etching composition of embodiment 1, wherein the additive comprises 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.

[0032] Aspect 4 2. The wet etching composition of embodiment 1, wherein the additive comprises at least one of n-dodecylphosphonic acid, and benzylphosphonic acid, or any combination thereof.

[0033] Aspect 5 2. The wet etching composition of embodiment 1, wherein the additive comprises at least one of trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphine oxide, triethylamine phosphate, monoammonium phosphate, and 5-methyl-1H-benzotriazole, or any combination thereof.

[0034] Aspect 6 2. The wet etching composition of embodiment 1, comprising 1 wt % to 20 wt % phosphoric acid, based on the total weight of the wet etching composition.

[0035] Aspect 7 2. The wet etching composition of embodiment 1, comprising 50% to 90% by weight of acetic acid, based on the total weight of the wet etching composition.

[0036] Aspect 8 2. The wet etching composition of embodiment 1, comprising 0.1 wt % to 20 wt % of nitric acid, based on a total weight of the wet etching composition.

[0037] Aspect 9 10. The wet etching composition of embodiment 1, wherein the wet etching composition is free of a tungsten compound.

[0038] Aspect 10 MoO x 2. The wet etching composition of embodiment 1, wherein x in the layer is 1 to 5.

[0039] Aspect 11 Obtaining a structure including a plurality of recesses and a molybdenum material disposed in the plurality of recesses; and contacting the structure with a wet etching composition to remove at least a portion of the molybdenum material; 1. A method comprising: phosphoric acid, acetic acid, nitric acid, and MoO x Additives to reduce the oxidation rate of the layer Including, The method wherein the additive is present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition.

[0040] Aspect 12 12. The method of embodiment 11, wherein the additive comprises at least one of an ammonium salt, an organic chloride salt, a phosphonic acid, a phosphine oxide, an ammonium salt of phosphoric acid, a benzotriazole, and a citric acid, or any combination thereof.

[0041] Aspect 13 12. The method of embodiment 11, wherein the additive comprises 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.

[0042] Aspect 14 12. The method of embodiment 11, wherein the additive comprises at least one of n-dodecylphosphonic acid and benzylphosphonic acid, or any combination thereof.

[0043] Aspect 15 12. The method of embodiment 11, wherein the additive comprises at least one of trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphine oxide, triethylamine phosphate, monoammonium phosphate, and 5-methyl-1H-benzotriazole, or any combination thereof.

[0044] Aspect 16 12. The method of embodiment 11, wherein the wet etching composition comprises 1 wt % to 20 wt % phosphoric acid, based on the total weight of the wet etching composition.

[0045] Aspect 17 12. The method of embodiment 11, wherein the wet etching composition comprises 50% to 90% by weight of acetic acid, based on the total weight of the wet etching composition.

[0046] Aspect 18 12. The method of embodiment 11, wherein the wet etching composition comprises 0.1 wt % to 20 wt % nitric acid, based on the total weight of the wet etching composition.

[0047] Aspect 19 12. The method of embodiment 11, wherein the wet etching composition does not include a tungsten compound.

[0048] Aspect 20 MoO x 12. The method of embodiment 11, wherein x in the layer is 1 to 5.

[0049] It should be understood that changes may be made in details, particularly in matters of materials of construction employed and shape, size and arrangement of parts, without departing from the scope of the present disclosure. The specification and described embodiments are exemplary, with the true scope and spirit of the present disclosure being indicated by the following claims.

Claims

1. 1. A wet etching composition for molybdenum comprising: phosphoric acid, acetic acid, nitric acid, and MoO ｘ Additives to reduce the oxidation rate of the layer Including, A wet etching composition, wherein the additive is present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition.

2. 10. The wet etching composition of claim 1, wherein the additive comprises at least one of an ammonium salt, an organic chloride salt, a phosphonic acid, a phosphine oxide, an ammonium salt of phosphoric acid, a benzotriazole, and a citric acid, or any combination thereof.

3. 10. The wet etching composition of claim 1, wherein the additive comprises 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.

4. 10. The wet etching composition of claim 1, wherein the additive comprises at least one of n-dodecylphosphonic acid, and benzylphosphonic acid, or any combination thereof.

5. 10. The wet etching composition of claim 1, wherein the additive comprises at least one of trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphine oxide, triethylamine phosphate, monoammonium phosphate, and 5-methyl-1H-benzotriazole, or any combination thereof.

6. 10. The wet etching composition of claim 1, comprising 1% to 20% by weight of phosphoric acid, based on the total weight of the wet etching composition.

7. 10. The wet etching composition of claim 1, comprising 50% to 90% by weight of acetic acid, based on the total weight of the wet etching composition.

8. 10. The wet etching composition of claim 1, comprising 0.1 to 20 wt. % nitric acid, based on the total weight of the wet etching composition.

9. 10. The wet etching composition of claim 1, which is free of tungsten compounds.

10. MoO ｘ 2. The wet etching composition of claim 1, wherein x in the layer is 1-5.

11. Obtaining a structure including a plurality of recesses and a molybdenum material disposed in the plurality of recesses; and contacting the structure with a wet etching composition to remove at least a portion of the molybdenum material; 1. A method comprising: phosphoric acid, acetic acid, nitric acid, and MoO ｘ Additives to reduce the oxidation rate of the layer Including, The method, wherein the additive is present in an amount of 0.01 wt % to 5 wt %, based on the total weight of the wet etching composition.

12. 12. The method of claim 11, wherein the additive comprises at least one of an ammonium salt, an organic chloride salt, a phosphonic acid, a phosphine oxide, an ammonium salt of phosphoric acid, a benzotriazole, and a citric acid, or any combination thereof.

13. 12. The method of claim 11, wherein the additive comprises 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.

14. 12. The method of claim 11, wherein the additive comprises at least one of n-dodecylphosphonic acid, and benzylphosphonic acid, or any combination thereof.

15. 12. The method of claim 11, wherein the additive comprises at least one of trioctylphosphine oxide, triphenylphosphine oxide, triphenylphosphine oxide, triethylamine phosphate, monoammonium phosphate, and 5-methyl-1H-benzotriazole, or any combination thereof.

16. 12. The method of claim 11, wherein the wet etching composition comprises 1% to 20% by weight of phosphoric acid, based on the total weight of the wet etching composition.

17. 12. The method of claim 11, wherein the wet etching composition comprises 50% to 90% by weight of acetic acid, based on the total weight of the wet etching composition.

18. 12. The method of claim 11, wherein the wet etching composition comprises 0.1 to 20 wt. % nitric acid, based on the total weight of the wet etching composition.

19. The method of claim 11 , wherein the wet etching composition does not include a tungsten compound.

20. MoO ｘ The method of claim 11, wherein x in the layer is 1 to 5.

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