Etching solution composition and method

Abstract

A composition and method for selectively etching titanium nitride, cobalt, or combinations thereof. The composition and method generally leave molybdenum and other materials unaffected by the process. The process can achieve high etching rates and can provide uniformly patterned upper and lower layers with a concave shape.

Description

[Technical Field]

[0001] This disclosure relates to the field of semiconductor manufacturing. Specifically, this disclosure relates to etching solution compositions and methods for etching titanium nitride films.

[0002] Priority This disclosure claims priority under U.S. Provisional Patent Application No. 63 / 346,748, filed on 27 May 2022. The priority document is incorporated herein by reference. [Background technology]

[0003] Photoresist masks can be used to pattern materials such as semiconductors or dielectrics. For example, a photoresist mask can be used in a dual damascene process to form interconnects for back-end metallization of microelectronic devices. A dual damascene process may require forming a photoresist mask on a low-k dielectric layer that covers a metallic conductive layer, such as a copper layer. The low-k dielectric layer can be etched according to the photoresist mask to form trenches that expose the metallic conductive layer. The trenches, commonly known as dual damascene structures, are typically defined using two lithography steps. Then, after the photoresist mask is removed from the low-k dielectric layer, the conductive material is deposited in the trenches to form interconnects. [Overview of the project]

[0004] In some embodiments, a metal mask is used to provide better profile control of the trench. The metal hard mask can be made of titanium or titanium nitride, and is removed by a wet etching process after forming the trench of the dual damascene structure. In some embodiments, the wet etching process effectively removes the metal hard mask and / or photoresist etching residue without affecting the underlying metal conductor layer and low-k dielectric material, or other materials on the microelectronic device. Some embodiments of the etchant composition include a metal conductor layer (e.g., molybdenum, AlO x , SiO x , or polysilicon), and can be used in a wet etching process to selectively remove substances such as titanium nitride while being compatible with the foregoing materials.

[0005] In some embodiments, the composition comprises an oxidizing agent, an etchant, a first corrosion inhibitor, and a second corrosion inhibitor comprising an N-heteroatom-containing aromatic compound.

[0006] In some embodiments of the present composition, the first corrosion inhibitor prevents chemical reaction of a first material comprising Cr, Mo, W, or any combination thereof.

[0007] In some embodiments of the present composition, the second corrosion inhibitor prevents chemical reaction of a second material.

[0008] In some embodiments of the present composition, the first corrosion inhibitor comprises 5-methylbenzotriazole.

[0009] In some embodiments of the present composition, the second corrosion inhibitor comprises polyvinylpyrrolidone.

[0010] In some embodiments of the present composition, the first corrosion inhibitor comprises 4-(3-phenylpropyl)pyridine.

[0011] In some embodiments of the present composition, the second corrosion inhibitor comprises polyvinylpyrrolidone.

[0012] In some embodiments, an etching method uses the composition described herein, and the method comprises removing TiN at a TiN removal rate of at least 5.0 nm / min. In some embodiments of the method, the TiN removal rate is at least 10 nm / min.

[0013] In some embodiments, the method further comprises removing Co at a Co removal rate of at least 20 nm / min. In some embodiments of the method, the Co removal rate is at least 25 nm / min.

[0014] In some embodiments of the method, the removal rate of the first material is less than 1.8 nm / min due to protection by the first corrosion inhibitor. In some embodiments of the method, the first material is Cr, Mo, W, or any combination thereof.

[0015] In some embodiments of the method, the removal rate of the second material is less than 0.5 nm / min due to protection by the second corrosion inhibitor. MODE FOR CARRYING OUT THE INVENTION

[0016] Among the benefits and improvements disclosed, other objects and advantages of the present disclosure will become apparent from the following description. While detailed embodiments of the present disclosure are disclosed herein, it should be understood that the embodiments of the present disclosure are merely illustrative of the present disclosure, which may be embodied in various forms. Furthermore, each of the examples given with respect to various embodiments of the present disclosure is intended to be illustrative, not limiting.

[0017] Throughout this specification and the claims, the following terms have the expressly relevant meanings as expressed herein unless the context clearly indicates otherwise. The phrases “in one embodiment,” “in an embodiment,” and “in some embodiments” as used herein may refer to the same embodiment, but not necessarily the same embodiment. Furthermore, the phrases “in another embodiment” and “in some other embodiments” as used herein may refer to different embodiments, but not necessarily different embodiments. All embodiments of this disclosure are intended to be combinatorial without departing from the scope or spirit of this disclosure.

[0018] As used herein, the term “microelectronic device” refers to semiconductor substrates, flat panel displays, phase-change memory devices, solar panels, and other products including photovoltaic devices, photovoltaics, and microelectromechanical systems (MEMS) manufactured for use in microelectronics, integrated circuits, energy collection, or computer chip applications. It should be understood that the terms “microelectronic device,” “microelectronic substrate,” and “microelectronic device structure” are not intended to be limiting and include any substrate or structure that will ultimately become a microelectronic device or microelectronic assembly. Microelectronic devices may be patterned, blanketed, control devices, and / or test devices.

[0019] As used herein, "titanium nitride" and "TiN" x The term "TiO" refers to both pure titanium nitride and impure titanium nitride (i.e., TiO) containing various stoichiometric and oxygen content. x N y ) corresponds to this.

[0020] Where used herein, "about" is intended to correspond to a range of + or -0.5% of the stated value.

[0021] As used herein, the term “low-k dielectric material” refers to any material used as a dielectric material in layered microelectronic devices, having a dielectric constant of less than approximately 3.5. In certain embodiments, the low-k dielectric material is silicon-containing organic polymer, silicon-containing hybrid organic / inorganic material, organosilicate glass (OSG), TEOS, fluorinated silicate glass (FSG), silicon dioxide, aluminum oxide (AlO2). x ), zirconium oxide (ZrO x This includes low-polarity materials such as ), and carbon-doped oxide (CDO) glass. It should also be recognized that low-k dielectric materials can have a variety of densities and porosities.

[0022] As used herein, the term “metallic conductive layer” includes copper, tungsten, cobalt, molybdenum, aluminum, ruthenium, alloys containing them, or combinations thereof.

[0023] As used herein, the term "fluoride" refers to ionic fluoride (F - ) or species having covalently bonded fluorine. Please understand that fluoride species may be included as fluoride species or may be generated in situ.

[0024] The compositions of the present invention can be embodied in a wide variety of specific formulations, as will be described in more detail below.

[0025] In all such compositions, the specific components of the composition are discussed in terms of a weight percentage range including zero, and it will be understood that such components may or may not be present in various specific embodiments of the composition, and that in the present examples, such components may be present at a low concentration of 0.0001 weight percent based on the total weight of the composition in which they are used.

[0026] In some embodiments, the present disclosure relates to compositions and processes for creating recesses in microelectronic device structures, for example, 3D NAND flash memory devices. Some embodiments of the present process can be characterized as including dry or wet etching processes, as well as processes in which a titanium nitride (TiN) layer is selectively etched, leaving some other materials overall unaffected by the present process, and any aluminum oxide, silicon dioxide, and polysilicon can also be present. In some embodiments, the present process can have an improved etching rate and can provide concave upper and lower layers with uniform patterns. In some embodiments, the composition is very stable, for example, the bath life is longer than 24 hours and the shelf life is longer than 6 months.

[0027] According to some embodiments, an exemplary material includes a TiN layer and a cobalt (Co) layer, wherein the TiN layer and the Co layer are selectively removed, leaving some other materials overall unaffected by the chemical etching process using the exemplary composition.

[0028] Some examples of other materials include, but are not necessarily limited to, a first material, a second material, silicon-based materials, and the like. According to some embodiments, examples of the first material include molybdenum (Mo) or Mo-containing alloys. According to some embodiments, examples of the first material are, or include, Cr, Mo, W, Cr-containing alloys, Mo-containing alloys, W-containing alloys, or any combination thereof. According to some embodiments, examples of silicon-based materials include silicon (Si), SiO x , silicon oxide, SiN x , silicon nitride (Si x N y ), polysilicon, or combinations thereof.

[0029] In some embodiments, the exemplary composition comprises an oxidizing agent, an etching solution, a first corrosion inhibitor, and a second corrosion inhibitor. The first corrosion inhibitor prevents a chemical reaction between the oxidizing agent and / or the etching solution and the first material. According to some embodiments, the composition selectively etches TiN and Co, but does not etch (i.e., chemically react with) the first material (e.g., Mo), and the chemical reaction does not etch (i.e., chemically react with) the oxide of the first material (e.g., MoO). x ) neither produce nor form. According to some embodiments, the composition selectively etches TiN and Co, but the first corrosion inhibitor in the composition does not etch (i.e., chemically react with) the first material (e.g., Mo). Therefore, even when using the composition, oxides of the first material (e.g., MoO) are not produced. x ) neither occurs nor is formed.

[0030] In some embodiments, the first corrosion inhibitor includes 5-methylbenzotriazole, benzotriazole, or a combination thereof.

[0031] In some embodiments, the first corrosion inhibitor is 5-methylbenzotriazole.

[0032] In some embodiments, the first corrosion inhibitor is benzotriazole.

[0033] Some embodiments of this composition further include one or more pH adjusters and a solvent (i.e., a solvent solution). In some embodiments, the composition includes a solvent that is a water-miscible solvent. In some embodiments of this composition, it includes water (e.g., deionized water). In some embodiments, the composition includes a water-miscible solvent and water (e.g., deionized water). In some embodiments of this composition, the etching solution is one or more TiN etchants. In some embodiments of this composition, the etching solution is a TiN etchant and a Co etchant, or includes them. In some embodiments of this composition, the etching solution is one or more TiN·Co etchants, or includes them.

[0034] Furthermore, according to some embodiments, for example, the material includes a TiN layer disposed above a Co layer. The Co layer is disposed above a Mo layer (an example of the first material). The Mo layer is Si x N y It is positioned above the material.

[0035] For example, according to some embodiments, the material includes a TiN layer disposed above a Co layer. The Co layer is disposed above a Mo layer (an example of a first material). The Mo layer is SiO x It is positioned above the material.

[0036] For example, according to some embodiments, the material includes a TiN layer disposed above a Co layer. The Co layer is disposed above a Mo layer (an example of a first material). The Mo layer is disposed above a Si material.

[0037] In some embodiments, the composition has a TiN etching rate of 5 nm / min or more (at 60°C).

[0038] In some embodiments, the composition has a Co etching rate of 20 nm / min or more (at 60°C).

[0039] In some embodiments, the composition has a TiN etching rate of 5 nm / min or more and a Co etching rate of 20 nm / min or more (at 60°C).

[0040] Exemplary materials include titanium nitride (TiN) and cobalt (Co) layers, which are selectively removed, leaving some other materials unaffected by the chemical etching process of the exemplary composition.

[0041] Other examples of certain materials include, but are not limited to, the first material, the second material, and silicon-based materials.

[0042] In some embodiments, the second material includes one or more transition metals.

[0043] In some embodiments, the exemplary composition includes an oxidizing agent, an etching solution, a first corrosion inhibitor, and a second corrosion inhibitor. The first corrosion inhibitor prevents a chemical reaction between the oxidizing agent and / or the etching solution and the first material. The second corrosion inhibitor contains an N-heteroatom-containing aromatic compound and prevents a chemical reaction between the oxidizing agent and / or the etching solution and the second material.

[0044] For example, according to some embodiments, the material includes a TiN layer disposed above a Co layer. The Co layer is disposed above a second material. The second material is Si x N y It is positioned above the material.

[0045] For example, according to some embodiments, the material includes a TiN layer disposed above a Co layer. The Co layer is disposed above a second material. The second material is SiO x It is positioned above the material.

[0046] For example, according to some embodiments, the material includes a TiN layer disposed above a Co layer. The Co layer is disposed above a second material. The second material is disposed above a Si material.

[0047] In some embodiments, the composition exhibits very high TiN etching selectivity at 60°C. In some embodiments, the composition has a TiN etching rate of 5 nm / min or more and a Co etching rate of 20 nm / min or more, and the composition contains Mo and Si x N y , and SiO x It is compatible with Mo, Si x N y , and SiO x It does not etch. In some embodiments, this composition contains Mo, Si x N y , and SiO x It doesn't react.

[0048] In some embodiments, at 60°C, the composition has a TiN etching rate of 5 nm / min or more and a Co etching rate of 20 nm / min or more, and the composition contains Mo and Si x N y , and SiO x , or compatibility with any combination thereof. In some embodiments, the composition is Mo, Si x N y , and SiO x , or any combination thereof, is not etched. In some embodiments, the composition contains Mo, Si x N y , and SiO x It does not react with, or with any combination thereof.

[0049] In some embodiments, a portion of the material comprises an exemplary material and another exemplary material, each of which comprises a titanium nitride (TiN) layer and a cobalt (Co) layer. The TiN and Co layers are selectively removed, so that the other portions of the material as a whole remain unaffected by the chemical etching process of the exemplary composition.

[0050] Other examples of certain materials include, but are not limited to, the first material, the second material, and silicon-based materials.

[0051] According to some embodiments, an example of the first material is molybdenum (Mo) or a Mo-containing alloy. According to some embodiments, an example of the first material is Cr, Mo, W, a Cr-containing alloy, a Mo-containing alloy, a W-containing alloy, or any combination thereof, or includes them.

[0052] According to some embodiments, examples of silicon-based materials include silicon (Si), SiO2. x silicon dioxide, SiN x Silicon nitride (Si x N y Examples include polysilicon, or combinations thereof.

[0053] In some embodiments, the exemplary composition includes an oxidizing agent, an etching solution, a first corrosion inhibitor, and a second corrosion inhibitor. The first corrosion inhibitor prevents a chemical reaction between the oxidizing agent and / or the etching solution and the first material.

[0054] In some embodiments, the exemplary composition comprises an oxidizing agent, an etching solution, a first corrosion inhibitor, and a second corrosion inhibitor. The first corrosion inhibitor prevents a chemical reaction between the oxidizing agent and / or the etching solution and the first material. The second corrosion inhibitor contains an N-heteroatom-containing aromatic compound and prevents a chemical reaction between the oxidizing agent and / or the etching solution and the second material. The composition is compatible with or does not react with silicon-based materials. That is, according to some embodiments, the composition reacts with TiN and Co at a rate much faster than the silicon-based material so that TiN and Co are removed much faster than the removal rate of the silicon-based material, or the composition reacts with TiN and Co but substantially does not react with the silicon-based material, and therefore TiN and Co are removed but the silicon-based material is not, or the composition reacts with TiN and Co but does not react with the silicon-based material, and therefore TiN and Co are removed but the silicon-based material is not.

[0055] In some embodiments, the composition is a TiN·Co etching solution composition comprising an oxidizing agent, an etching solution, a first corrosion inhibitor, and a second corrosion inhibitor, wherein the first corrosion inhibitor comprises 5-methylbenzotriazole and 4-(3-phenylpropyl)pyridine, and the second corrosion inhibitor comprises polyvinylpyrrolidone. In some embodiments, the composition further comprises a pH adjuster and deionized water.

[0056] In some embodiments of this composition, the chemical reaction is MoO x It neither causes nor forms.

[0057] According to some embodiments, the intended etching solution may include, but is not limited to, fluoride sources such as HF, ammonium fluoride, tetrafluoroboric acid, hexafluorosilicic acid, other compounds containing B--F or Si--F bonds, strong bases such as tetrabutylammonium tetrafluoroborate (TBA-BF4), tetraalkylammonium fluoride (NR1R2R3R4F), and tetraalkylammonium hydroxide (NR1R2R3R4OH), where R1, R2, R3, and R4 may be the same or different from each other, and are selected from hydrogen, linear or branched C1-C6 alkyl groups (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl), C1-C6 alkoxy groups (e.g., hydroxyethyl, hydroxypropyl), substituted or unsubstituted aryl groups (e.g., benzyl), weak bases, or combinations thereof. In one embodiment, the fluoride source includes HF, tetrafluoroboric acid, hexafluorosilicic acid, H2ZrF6, H2TiF6, HPF6, ammonium fluoride, tetramethylammonium fluoride, tetramethylammonium hydroxide, ammonium hexafluorosilicate, ammonium hexafluorotiatanate, or a combination of ammonium fluoride and tetramethylammonium fluoride. In another embodiment, the etching solution includes HF, hexafluorosilicic acid, or tetrafluoroboric acid. In yet another embodiment, the etching solution is HF.

[0058] According to some embodiments, TiN x Ca in the film 3+Oxidizing agents included for etching or oxidation. Oxidizing agents as intended herein include hydrogen peroxide (H2O2), FeCl3, FeF3, Fe(NO3)3, Sr(NO3)2, CoF3, MnF3, Oxone® (2KHSO5·KHSO4·K2SO4 - CAS number 70693-62-8), periodic acid, iodic acid, t-butyl hydroperoxide, vanadium(V) oxide, vanadium(IV,V) oxide, ammonium vanadate, and polyatomic ammonium salts. salt) (e.g., ammonium peroxomonosulfate, ammonium chlorite (NH4ClO2), ammonium chlorate (NH4ClO3), ammonium iodate (NH4IO3), ammonium nitrate (NH4NO3), ammonium perborate (NH4BO3), ammonium perchlorate (NH4ClO4), ammonium periodate (NH4IO4), ammonium persulfate ((NH4)2S2O8), ammonium hypochlorite (NH4ClO)), ammonium tungstate ((NH4) 10H2(W2O7)), sodium polyatomic salts (e.g., sodium persulfate (Na2S2O8), sodium hypochlorite (NaClO), sodium perborate), potassium polyatomic salts (e.g., potassium iodate (KIO3), potassium permanganate (KMnO4), potassium persulfate, nitric acid (HNO3), potassium persulfate (K2S2O8), potassium hypochlorite (KClO)), tetramethylammonium polyatomic salts (e.g., tetramethylammonium chlorite ((N(CH3)4)ClO2), tetramethylammonium chlorate ((N(CH3)4)ClO3), tetramethylammonium iodate ((N(CH3)4)IO3), tetramethylammonium perborate) Examples of oxidizing agents include, but are not limited to, nium ((N(CH3)4)BO3), tetramethylammonium perchlorate ((N(CH3)4)ClO4), tetramethylammonium periodate ((N(CH3)4)IO4), tetramethylammonium persulfate ((N(CH3)4)S2O8)), tetrabutylammonium polyatomic salts (e.g., tetrabutylammonium peroxomonosulfate), peroxomonosulfate, ferric nitrate (Fe(NO3)3), urea hydrogen peroxide ((CO(NH2)2)H2O2), peracetic acid (CH3(CO)OOH), 1,4-benzoquinone, tolquinone, dimethyl-1,4-benzoquinone, chloranil, alloxane, or combinations thereof. If the oxidizing agent is a salt, it may be hydrated or anhydrous. The oxidizing agent may be introduced into the composition by the manufacturer before introducing the composition onto the device wafer, or alternatively, on the device wafer, i.e., in situ. In one embodiment, the oxidizing agent includes periodic acid.

[0059] The pH of this composition can be adjusted using any suitable compound capable of adjusting its pH. The pH adjuster is preferably water-soluble and compatible with the other components of the composition. Typically, the composition has a pH of approximately -1 to 5, 0 to 4, or 2 to 4 at the time of use. Non-limiting examples of pH adjusters include mineral and organic acids, such as methanesulfonic acid, ethanesulfonic acid phosphoric acid, sulfuric acid, and hydrogen chloride.

[0060] In some embodiments, the solvent may include water, at least one water-miscible organic solvent, or a combination thereof, wherein the at least one water-miscible organic solvent is of formula R 1 R 2 R 3 Selected from the group consisting of C(OH) compounds, where R 1 , R 2 , and R 3 They are independent of each other, and hydrogen, C2~C 30 Alkyl, C2~C 30 Alkenes, cycloalkyls, C2-C 30The solvent is selected from the group consisting of alkoxys and combinations thereof. For example, at least one solvent is water, methanol, ethanol, isopropanol, butanol, and higher alcohols (tetrahydrofurfuryl alcohol (THFA), 3-chloro-1,2-propanediol, 3-chloro-1-propanthol, 1-chloro-2-propanol, 2-chloro-1-propanol, 3-chloro-1-propanol, 3-bromo-1,2-propanediol, 1-bromo-2-propanol, 3-bromo-1-propanol, 3-iodo-1-propanol, 4-chloro-1-butanol, 2-chloroethanol), dichloromethane, chloroform, acetic acid, propionic acid, triglycerides. Fluoroacetic acid, tetrahydrofuran (THF), N-methylpyrrolidinone (NMP), cyclohexylpyrrolidinone, N-octylpyrrolidinone, N-phenylpyrrolidinone, methyldiethanolamine, methyl formate, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), tetramethylene sulfone (sulfolane), diethyl ether, phenoxy-2-propanol (PPh), propriophenone, ethyl lactate, ethyl acetate, ethyl benzoate, acetonitrile, acetone, ethylene glycol, propylene glycol (PG), 1,3-propanediol, 1,4-Propanediol, dioxane, butyryl lactone, butylene carbonate, ethylene carbonate, propylene carbonate, dipropylene glycol, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether, diethylene glycol monoethyl ether, triethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether (i.e., butyl carbitol), triethylene glycol monobutyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, ethylene glycol phenyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPGME), It may contain at least one species selected from the group consisting of tripropylene glycol methyl ether (TPGME), dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, propylene glycol n-propyl ether, dipropylene glycol n-propyl ether (DPGPE), tripropylene glycol n-propyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, dipropylene glycol methyl ether acetate, tetraethylene glycol dimethyl ether (TEGDE), dibasic esters, glycerin carbonate, N-formylmorpholine, triethyl phosphate, or combinations thereof. In one embodiment, at least one solvent includes water, for example, deionized water. In one embodiment, the water-miscible solvent is selected from ethylene glycol and propylene glycol.

[0061] Non-limiting and illustrative compositions are listed below.

[0062] Composition example TIFF0007918289000001.tif47170

[0063] Using the above example composition (etching at 60°C), a TiN etching rate exceeding 10 nm / min was achieved. Using the same example composition, a Co etching rate of 28.9 nm / min or higher was also obtained. Furthermore, a Mo etching rate of less than 1.8 nm / min was achieved. Under some conditions, a Mo etching rate of less than 1.5 nm / min was achieved. Under some conditions, a Mo etching rate of less than 0.7 nm was achieved. SiN etching rate of less than 0.1 nm / min x The etching speed was also achievable.

Claims

1. Oxidizing agent, Etching solution and A first corrosion inhibitor that prevents chemical reactions of a first material containing Cr, Mo, W, or any combination thereof, The second corrosion inhibitor and Includes, A composition comprising a second corrosion inhibitor containing an N-heteroatom-containing aromatic compound, The second corrosion inhibitor contains polyvinylpyrrolidone. The composition has a Co removal rate of at least 20 nm / min. composition.

2. The composition according to claim 1, wherein the first corrosion inhibitor comprises 5-methylbenzotriazole.

3. The composition according to claim 2, wherein the first corrosion inhibitor further comprises 4-(3-phenylpropyl)pyridine.

4. A method of etching using the composition described in claim 1, Remove TiN at a TiN removal rate of at least 5.0 nm / min. To remove Co at a Co removal rate of at least 20 nm / min, and 1. Remove the first material at a removal rate of less than 1.8 nm / min. A method that includes this.

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