Method and apparatus for depositing chalcogenide films and film-containing structures

Abstract

To provide a method for depositing a group 5 chalcogenide on a base material.SOLUTION: The method for depositing a structure comprises: supplying a base material to a reaction chamber; supplying a group 5 precursor to the reaction chamber; supplying a chalcogen reactant to the reaction chamber; and a periodic deposition process, for example, periodic chemical vapor deposition (CVD) and / or atomic layer deposition (ALD); and additionally or alternatively forming a layer including a 2D group 5 chalcogenide on the base material and / or forming a layer including a group 5 metal chalcogenide on the base material. The group 5 chalcogenide material can be a group 5 dichalcogenide material or can include the same.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] Parties to the Joint Research Agreement The invention claimed in this application was made by, for, and / or in connection with a Joint Research Agreement between the University of Helsinki and ASM Microchemistry Oy, which was in effect on or before the date the claimed invention was made, and which resulted from activities undertaken within the scope of the Agreement.

[0002] The present disclosure generally relates to methods and systems for depositing chalcogenide films on substrates. The present disclosure also relates to structures including chalcogenide films. [Background technology]

[0003] Group 5 and other transition metal dichalcogenides (TMDCs) can be represented by the formula MX2, where M represents a transition metal (e.g., a Group 5 metal) and X represents a chalcogenide, such as sulfur, selenium, or tellurium. Exemplary TMDCs include MOS2 and WSe2. TMDCs include semiconductor, semimetal, and metallic materials.

[0004] Most research has investigated the properties of semiconducting TMDCs, particularly those of group 6 disulfides and selenides, such as MoS2, MoSe2, WS2, and WSe2. Semiconducting TMDCs are very important in practice and perform well in some applications, such as field-effect transistors and photodetectors. However, for other applications, more conductive films are desirable. Some examples of such applications include various energy applications, such as water splitting catalysts (hydrogen evolution reaction (HER) and oxygen evolution reaction (OER)), supercapacitors, and batteries. Furthermore, forming electrical contacts to semiconducting TMDCs using conventional metals with 3D crystalline structures, such as gold and tungsten, has proven extremely challenging.

[0005] The Group 5 dichalcogenides, i.e., VS2, VSe2, VTe2, NbS2, NbSe2, NbTe2, TaS2, TaSe2, and TaTe2, are considered to be either metals or semimetals with high electrical conductivity. Many of the Group 5 dichalcogenides exhibit phase changes, either becoming superconducting at low temperatures and / or exhibiting different charge density wave (CDW) phases at different temperatures, both of which properties are beneficial in a variety of electronic devices.

[0006] For many applications, it may be desirable to deposit dichalcogenide materials in a two-dimensional (2D) (layered crystalline structure) form. Currently, there are few, if any, methods for depositing uniform films of Group 5 dichalcogenides in ultrathin (e.g., less than 10 nm or less than 5 nm) 2D form.

[0007] Although mechanical exfoliation of bulk crystals has been used for fundamental research, such processes are very difficult to scale up for manufacturing. Physical vapor deposition (PVD) methods, including evaporation and molecular beam epitaxy (MBE), have been reported primarily for the deposition of group 5 sulfides and selenides, respectively. Unfortunately, deposition of films using MBE requires very expensive UHV equipment. Chemical vapor deposition (CVD) is perhaps the most commonly applied technique for depositing group 5 dichalcogenides. However, CVD typically requires high temperatures, from approximately 600 °C to approximately 1000 °C, and it can be difficult to deposit thin, continuous dichalcogenide films using CVD.

[0008] Chalcogenization of metal or metal oxide films to form dichalcogenide materials has also been reported. Chalcogenization may be more scalable and better at producing continuous films than previously reported CVD processes, but the resulting chalcogen films may be limited by grain size, and chalcogenization methods use relatively high reaction temperatures similar to those used for CVD of dichalcogenide materials. While several CVD processes operating at low temperatures have been reported, most of these reports deal with films at least a few hundred nanometers thick, which would not be considered 2D.

[0009] Therefore, improved methods for fabricating chalcogenide materials, such as 2D chalcogenide materials, are desired. Improved systems for forming chalcogenide materials and structures including chalcogenide materials are also desired.

[0010] All descriptions, including descriptions of problems and solutions described in this section, are included in this disclosure solely for the purpose of providing a context for the disclosure and should not be construed as an admission that any or all of the descriptions were known or constitute prior art at the time the invention was made. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] U.S. Patent No. 6,632,279 Summary of the Invention [Means for solving the problem]

[0012] This Summary is provided to introduce a selection of concepts in a simplified form. These concepts are described in more detail below in the Detailed Description of Exemplary Embodiments of this Disclosure. This Summary is not necessarily intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0013] According to exemplary embodiments of the present disclosure, methods are provided for forming structures including layers comprising chalcogenide materials, e.g., dichalcogenide materials. While various drawbacks of the prior art methods are described in more detail below, generally, exemplary methods involve techniques suitable for forming 2D (e.g., metallic or conductive) films of dichalcogenide materials. (e.g., 2D or metallic) dichalcogenide materials can be used to overcome the Fermi level pinning problem observed in 3D metals, significantly reduce contact resistance to other materials, and for several other applications. Another exemplary embodiment relates to structures including layers comprising chalcogenide materials, e.g., dichalcogenide materials, and / or systems for performing the methods described herein and / or forming structures.

[0014] According to an exemplary embodiment of the present disclosure, a method for forming a structure includes providing a substrate in a reaction chamber, providing a Group 5 precursor in the reaction chamber, and providing a chalcogen reactant in the reaction chamber. The method can include a cyclic deposition process, such as cyclic chemical vapor deposition (CVD) and / or atomic layer deposition (ALD). Additionally or alternatively, the method can include forming a layer on the substrate including a 2D Group 5 chalcogenide and / or forming a layer on the substrate including a Group 5 metal chalcogenide. The Group 5 chalcogenide material can be or can include a Group 5 dichalcogenide material. The temperature in the reaction chamber during one or more of the steps can be about 50°C to about 500°C, about 100°C to about 600°C, or about 300°C to about 500°C. The pressure in the reaction chamber during one or more of the steps can be about 10 -7 ~approx. 1000 mbar, approx. 10 -4 ~approx. 100 mbar, approx. 10 -2 ~ about 50 mbar, or about 10 -1The pressure can be up to about 10 mbar. The Group 5 precursor can be or include one or more of a tantalum precursor, a niobium precursor, and a vanadium precursor. The Group 5 precursor can be or include a nitrogen coordination compound, such as a compound containing one or more of an amide ligand and an amido ligand. Additionally or alternatively, the Group 5 precursor can be or include a homoleptic compound or a heteroleptic compound. Exemplary chalcogen reactants can be or include one or more of a sulfur reactant, a selenium reactant, and a tellurium reactant. For example, the chalcogen reactant can include one or more of H2S, S(SiMe3)2, Se(SiEt3)2, alkyl substituents on alkylsilyl groups (SiR3), H2Se, and / or other precursors described herein. Exemplary methods can further include an annealing step, e.g., at a temperature less than 800°C, or less than 600°C, or less than 500°C, or even less than 400°C, or between about 400°C and about 500°C. The annealing step can be carried out in a chalcogen-containing (e.g., elemental S, Se, Te, or H2S) environment. Additionally or alternatively, the environment can include H2 or an inert atmosphere (e.g., N2, Ar, He) atmosphere, e.g., for less than 1 hour, less than 30 minutes, less than 15 minutes, or less than 5 minutes.

[0015] According to another embodiment of the present disclosure, a structure is provided. The structure can include a substrate and a layer including a Group 5 chalcogenide overlying the substrate. The layer can be a 2D Group 5 chalcogenide, a Group 5 metal chalcogenide, and / or a dichalcogenide material. The substrate can include a layer of a semiconductor material (e.g., a semiconductor material including a chalcogenide material), and the layer including the Group 5 chalcogenide can form a contact layer with the semiconductor material.

[0016] According to another exemplary embodiment of the present disclosure, a device includes the structure described herein. Exemplary devices can include semiconductor devices, supercapacitors, batteries, electrochemical devices, etc.

[0017] According to yet another embodiment of the present disclosure, there is provided a system for depositing chalcogenide materials, which can be used to perform methods and / or form structures as described herein.

[0018] These and other embodiments will be readily apparent from the following detailed description of several embodiments, which refers to the accompanying drawings, and the invention is not limited to any particular embodiment disclosed.

[0019] While this specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present disclosure, the advantages of the presently disclosed embodiments may be more readily ascertained from the following description of certain specific examples of the presently disclosed embodiments when read in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0020] [Figure 1] A method according to at least one embodiment of the present disclosure. [Figure 2] 1 is a structure according to at least one embodiment of the present disclosure. [Figure 3] 1 is an exemplary system in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0021] It should be understood that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the illustrated embodiments of the present disclosure. Furthermore, the figures shown herein are not necessarily intended to be actual views of particular materials, structures, systems, or devices, but rather may be idealized representations used to facilitate description of exemplary embodiments of the present disclosure.

[0022] Although certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, as well as obvious modifications and equivalents thereof. Therefore, it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments set forth below.

[0023] The present disclosure generally relates to methods for forming structures including layers containing five chalcogenides, structures formed using the methods, and systems for performing the methods and / or forming the structures. Using the exemplary methods described herein, structures including dichalcogenides, 2D Group 5 chalcogenides, and / or Group 5 metal chalcogenides can be formed on a substrate. The structures can be used to form various devices, such as semiconductor devices (e.g., as contact layers to semiconductor layers), supercapacitors, (e.g., lithium ion) batteries, electrochemical (e.g., water splitting catalyst) devices, etc.

[0024] As used herein, the term "structure" can include substrates and layers. The structure can form part of a device, such as a device described herein. The structure can be subjected to further processing, such as deposition, etching, cleaning, and similar process steps, to form a device.

[0025] As used herein, the term "substrate" can refer to any underlying material or materials upon which a layer can be deposited. The substrate can include a bulk material, such as silicon (e.g., monocrystalline silicon), or other semiconductor material, and can include one or more layers, such as a native oxide or another layer, above or below the bulk material. Furthermore, the substrate can include various topologies, such as recesses, lines, etc., formed within or on at least a portion of the layer and / or bulk material of the substrate. As specific examples, the substrate can include one or more materials, including, but not limited to, silicon (Si), germanium (Ge), germanium tin (GeSn), silicon germanium (SiGe), silicon germanium tin (SiGeSn), silicon carbide (SiC), or a III-V semiconductor material, such as gallium arsenide (GaAs), gallium phosphide (GaP), or gallium nitride (GaN). In some embodiments, the substrate can include one or more dielectric materials, including, but not limited to, an oxide, a nitride, or an oxynitride. For example, the substrate can include silicon oxide (e.g., SiO), metal oxide (e.g., AlO), silicon nitride (e.g., SiN), or silicon oxynitride. In some embodiments of the present disclosure, the substrate can include a processed substrate having a surface semiconductor layer disposed on a bulk support with an intervening buried oxide (BOX) disposed therebetween. The patterned substrate can include features formed in or on the surface of the substrate; for example, the patterned substrate can include partially fabricated semiconductor device structures, such as transistors and / or memory elements. In some embodiments, the substrate can include one or more second surfaces that can include a single crystalline surface and / or an amorphous surface, such as a polycrystalline surface and / or a non-crystalline surface. The single crystalline surface can include, for example, one or more of silicon, silicon germanium, germanium tin, germanium, or a III-V material. The polycrystalline or amorphous surface can include a dielectric material, such as an oxide, oxynitride, or nitride, such as silicon oxide and silicon nitride.

[0026] In this disclosure, the term "gas" can refer to a material that is a gas, vaporized solid, and / or vaporized liquid at room temperature and atmospheric pressure, and may be composed of a single gas or a mixture of gases, depending on the context. Gases other than process gases, such as gases introduced without passing through a gas distribution assembly, e.g., a showerhead, other gas distribution device, etc., may be used, for example, to seal the reaction space, and the reaction space may contain a sealing gas, e.g., a noble gas. In some embodiments, the term "precursor" generally refers to a compound that participates in a chemical reaction to produce another compound, particularly a compound that constitutes the membrane matrix or the main framework of the membrane, and the term "reactant" refers to a compound that activates, modifies, or catalyzes the reaction of a precursor; reactants provide elements (e.g., chalcogens) to the membrane matrix and can become part of the membrane matrix. In some cases, the terms "precursor" and "reactant" can be used interchangeably. The term "inert gas" can refer to a gas that does not participate in a chemical reaction and / or a gas that excites a precursor when (e.g., RF) power is applied, but, unlike reactants, may not become part of the membrane to a significant extent.

[0027] As used herein, the term "cyclic deposition" can refer to a process of depositing a film on a substrate using the sequential introduction of precursors (and / or reactants) into a reaction chamber, and includes deposition techniques such as atomic layer deposition (ALD), cyclic chemical vapor deposition, and hybrid atomic layer deposition, and chemical vapor deposition processes.

[0028] As used herein, the term "atomic layer deposition" can refer to a vapor deposition process in which deposition cycles, e.g., multiple consecutive deposition cycles, are performed in a reaction chamber. Typically, during each cycle, a precursor is chemisorbed to the deposition surface (e.g., the surface of a substrate or a previously deposited underlying surface, e.g., material from a previous ALD cycle), forming a monolayer or submonolayer that does not readily react with another precursor (i.e., a self-limiting reaction). A reactant may then be introduced into the process chamber for use in converting the chemisorbed precursor to the desired material on the deposition surface. Typically, this reactant can further react with the precursor. Additionally, a purge step can be utilized during each cycle to remove excess precursor from the process chamber and / or to remove excess reactants and / or reaction by-products from the process chamber. As used herein, the term "ALD" is also meant to include processes denoted by related terms, such as chemical vapor atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, or metalorganic MBE, and chemical beam epitaxy, when carried out with alternating pulses of precursor and reactant, and optionally purge (e.g., inert) gases.

[0029] As used herein, the terms "cyclical chemical vapor deposition" or "cyclic chemical vapor deposition" can refer to any process in which a substrate is sequentially exposed to two or more volatile precursors that react and / or decompose on the substrate to produce a desired deposit.

[0030] As used herein, the term "film" can refer to any continuous or discontinuous structure and material, such as materials deposited by the methods disclosed herein. For example, a "film" can include a 2D material, or a partial or complete molecular layer, or a partial or complete atomic layer, or a cluster of atoms and / or molecules. A film can include materials with pinholes, but is at least partially continuous. The terms "film" and "layer" can be used interchangeably.

[0031] As used herein, the terms "2D material," "two-dimensional material," or simply "2D" can refer to nanometer-scale crystalline materials with thicknesses of about 1, 2, or 3 atoms. Such terms can also refer to ordered nanometer-scale crystalline structures composed of multiple monolayers of crystalline material with thicknesses of about 3 atoms per monolayer.

[0032] As used herein, the term "chalcogen reactant" can refer to a reactant containing chalcogen, where chalcogen is an element in Group 16 of the periodic table. According to various embodiments of the present disclosure, the chalcogen is selected from the group consisting of sulfur, selenium, and tellurium.

[0033] As used herein, the term "Group 5 chalcogenide" can refer to a material that can be represented by a chemical formula that includes one or more elements from Group 5 of the periodic table and one or more chalcogen elements. As a specific example, the chemical formula of a Group 5 chalcogenide can include one or more of vanadium, niobium, and tantalum.

[0034] As used herein, the term "Group 5 precursor" can refer to a precursor that includes at least one of the Group 5 metals, such as tantalum, niobium, and vanadium.

[0035] As used herein, the term "halide precursor" can refer to a halide precursor that includes a halide component, such as at least one of fluorine, chlorine, iodine, and bromine.

[0036] As used herein, the term "metal organic precursor" can refer to a metal organic precursor of a Group 5 metal. The terms "metal organic" or "organometallic" can be used interchangeably to refer to an organic compound containing a metal species. Organometallic compounds can be considered a subclass of metal organic compounds that have a direct metal-carbon bond.

[0037] As used herein, the term "tantalum precursor" can refer to a precursor that can be represented by a chemical formula that includes tantalum. Similarly, the term "niobium precursor" can refer to a precursor that can be represented by a chemical formula that includes niobium, and the term "vanadium precursor" can refer to a precursor that can be represented by a chemical formula that includes vanadium.

[0038] It should be noted that many example materials are provided throughout this disclosure and the chemical formula provided for each example material should not be construed as limiting, nor should the non-limiting example materials provided be limited by any example stoichiometry.

[0039] As described above, typical methods for forming layers of chalcogenide materials include mechanical exfoliation of bulk chalcogenide crystals, physical vapor deposition, chemical vapor deposition, and chalcogenization. While such methods can be used to deposit or form some chalcogenide films for some applications, such methods are generally not suitable for forming layers containing Group 5 chalcogenides with desired thicknesses and / or precision. Furthermore, such techniques may require undesirably high temperatures to deposit or form the chalcogenide material and / or cannot be used to form 2D and / or Group 5 metal chalcogenides.

[0040] In contrast, exemplary methods of the present disclosure can be used to form structures that include metal layers that include Group 5 chalcogenides, such as Group 5 dichalcogenides, 2D and / or Group 5 chalcogenides.

[0041] Referring now to the figures, Figure 1 illustrates a method 100 according to an exemplary embodiment of the present disclosure. Method 100 includes providing a substrate into a reaction chamber (step 102), providing a Group 5 precursor into the reaction chamber (step 104), providing a chalcogen reactant into the reaction chamber (step 106), and forming a layer comprising a Group 5 chalcogenide on the substrate (step 108). Although illustrated as separate steps, at least a portion of the layer comprising a Group 5 chalcogenide can begin to form when the chalcogen reactant is introduced into the reaction chamber, as described in more detail below.

[0042] According to exemplary embodiments of the present disclosure, method 100 includes a cyclic deposition technique, such as cyclic chemical vapor deposition, ALD, or a hybrid ALD / CVD technique. Such techniques are generally scalable and can provide atomic-level film thickness control, which is desirable for forming high-quality 2D and / or Group 5 metal chalcogenide (e.g., dichalcogenide) materials. Furthermore, cyclic deposition techniques, such as ALD, that provide surface control in the reaction are generally conformal, allowing three-dimensional structures to be uniformly coated with the desired material.

[0043] Group 5 chalcogenide films can be susceptible to oxidation either during the deposition process or when exposed to environmental conditions. Therefore, cyclic deposition methods that do not incorporate oxide phases into the chalcogenide film during deposition and / or that mitigate oxidation of Group 5 chalcogenide films when exposed to ambient conditions may be desirable.

[0044] In a cyclic process, one deposition cycle can include exposing a substrate to a first vapor-phase reactant, removing any unreacted first reactant and reaction by-products from the reaction space, and exposing the substrate to a second vapor-phase reactant, followed by a second removal step. The first reactant can include a Group 5 precursor, and the second reactant can include a chalcogen-containing precursor (chalcogen reactant).

[0045] In some embodiments, the cyclical deposition can be a hybrid ALD / CVD or cyclical CVD process. For example, in some embodiments, the deposition rate of an ALD process may be low compared to a CVD process. One way to increase the deposition rate is to operate at a higher substrate temperature than typically used in an ALD process, resulting in a chemical vapor deposition process, but also utilizing sequential introduction of precursors; such a process may be referred to as cyclical CVD. In some embodiments, the cyclical CVD process can include the introduction of two or more precursors into a reaction chamber, with a period of overlap between the two or more precursors in the reaction chamber resulting in both the ALD component of the deposition and the CVD component of the deposition. For example, a cyclical CVD process can include a continuous flow of a first precursor and periodic pulses of a second precursor into the reaction chamber.

[0046] The reaction chamber of the exemplary cyclical deposition process 100 may be part of a system described below, such as system 300. Exemplary reactors, including reaction chambers, suitable for use in method 100 include ALD reactors and CVD reactors equipped with appropriate equipment and means for providing precursors / reactants. According to some embodiments, the reactor is equipped with a showerhead for distributing one or more gases within the reaction chamber. In some embodiments, the reactor is a spatial ALD reactor, in which reactants / precursors are spatially separated by moving the substrate during processing.

[0047] In some embodiments, a batch reactor can be used. In some embodiments, a vertical batch reactor is utilized in which a boat carrying the substrates can rotate during processing. In some embodiments, the substrates can rotate during processing. In other embodiments, the batch reactor comprises a mini-batch reactor configured to accommodate 10 or fewer wafers, 8 or fewer wafers, 6 or fewer wafers, 4 or fewer wafers, or 2 wafers. In some embodiments in which a batch reactor is used, wafer-to-wafer non-uniformity is less than 3% (1 sigma), less than 2%, less than 1%, or even less than 0.5%.

[0048] The deposition processes described herein can be performed in reactors or reaction chambers connected to a cluster tool, if desired. In a cluster tool, each reaction chamber can be dedicated to one type of process, allowing the reaction chamber temperature within each module to be kept constant, improving throughput compared to reactors that heat substrates to process temperature before each run. Additionally, a cluster tool can reduce the time it takes to evacuate the reaction space to the desired process pressure level between substrates.

[0049] A stand-alone reactor is equipped with a load lock, in which case it is not necessary to cool the reaction chamber between runs.

[0050] In some embodiments of the present disclosure, the reaction chamber may undergo a pre-annealing process before introducing the substrate into the reaction chamber or after the substrate has been introduced into the reaction chamber. For example, the pre-annealing process may be used to reduce the concentration of at least one of water and / or oxygen in the reaction chamber. Accordingly, some embodiments of the present disclosure may further include pre-annealing the reaction chamber at a temperature greater than 400°C, greater than 500°C, greater than 600°C, or even greater than 700°C prior to film deposition. In some embodiments, pre-annealing the reaction chamber at high temperatures may be performed for less than 60 minutes, less than 30 minutes, less than 15 minutes, less than 10 minutes, or even less than 5 minutes.

[0051] 1, step 102 involves providing a substrate within a reaction chamber. During step 102, the substrate can be heated to a deposition temperature and the reaction chamber can be brought to a desired operating pressure.

[0052] As a non-limiting example, the substrate may be heated to a deposition temperature. For example, in some embodiments, the method can include heating the substrate (and / or reaction chamber) to a temperature of about 50°C to about 500°C, about 100°C to about 600°C, about 300°C to about 500°C, or further heating the substrate to a temperature of about 350°C to about 450°C. Of course, the suitable temperature window for any given cyclic deposition process, e.g., an ALD reaction, will depend on the surface termination and the reactant species involved. Here, the temperature will vary depending on the precursors used and is generally about 700°C or less. In some embodiments, for vapor deposition processes, the deposition temperature is generally about 100°C or greater. In some embodiments, the deposition temperature is about 100°C to about 600°C, and in some embodiments, the deposition temperature is about 300°C to about 500°C. In some embodiments, the deposition temperature is less than about 500°C, or less than about 475°C, or less than about 450°C, or less than about 425°C, or less than about 400°C, or less than about 375°C, or less than about 350°C, or less than about 325°C or less, or less than about 300°C. In some embodiments, for example, when another reactant or reducing agent is used in the process, the deposition temperature may be less than about 250°C, or less than about 200°C, or less than about 150°C, or less than about 100°C. In some cases, the deposition temperature can be greater than about 20°C, greater than about 50°C, and greater than about 75°C. The pressure in the reaction chamber is about 10 -7 ~approx. 1000 mbar, approx. 10 -4 ~approx. 100 mbar, approx. 10 -2 ~ about 50 mbar, or about 10 -1 It can be up to about 10 mbar.

[0053] During step 104, a Group 5 precursor is provided into the reaction chamber. According to various embodiments of the present disclosure, the Group 5 precursor includes one or more of a tantalum precursor, a niobium precursor, and a vanadium precursor. In some embodiments, the Group 5 precursor includes at least one of a metal organic compound, an organometallic compound, and a metal halide compound. According to exemplary embodiments, the Group 5 precursor includes a nitrogen coordination compound. In some embodiments of the present disclosure, the Group 5 precursor includes one or more bidentate ligands bonded to the Group 5 element through nitrogen and / or oxygen atoms. In some embodiments, the Group 5 precursor includes one or more ligands bonded to the Group 5 atom through nitrogen, oxygen, and / or carbon.

[0054] In some embodiments, the metal organic precursor may be nitrogen-coordinated, for example, comprising one or more of an amide ligand, an amido ligand, or an imido ligand. In some embodiments, the Group 5 precursor comprises a heteroleptic compound. In other embodiments, the Group 5 precursor comprises a homoleptic compound.

[0055] By way of example, the tantalum precursor can be or include one or more of a tantalum metal organic compound, a tantalum organometallic compound, and a tantalum halide compound. According to exemplary embodiments, the tantalum precursor includes one or more of nitrogen coordination compounds, such as amides, imides, and amidinates. In some embodiments, the tantalum metal organic precursor includes amide ligands (e.g., Ta(NEtMe)5 and Ta(NMe2)5) and imide ligands (e.g., both types of ligands, e.g., Ta(N tBu)(NEt2)3). In some embodiments, the tantalum precursor comprises a heteroleptic compound. The heteroleptic compound can include Cp and a halogen, such as chloride, or Cp and an alkylamine, or an amide and a halogen, such as chloride. In other embodiments, the tantalum precursor comprises a homoleptic compound. As described herein, in some embodiments, the tantalum halide precursor can include at least one halogen ligand, while the remaining ligands, such as metallo-organic or organometallic ligands, are different. In some embodiments, the tantalum halide precursor can include one, two, three, four, or five halogen ligands. In some embodiments, the tantalum metallo-organic precursor can include at least one of a tantalum alkylamide precursor, a tantalum cyclopentadienyl ligand-containing precursor, or another metallo-organic tantalum precursor. In some embodiments of the present disclosure, the tantalum precursor includes one or more bidentate ligands bonded to the tantalum through a nitrogen and / or oxygen atom. In some embodiments, the tantalum precursor comprises one or more ligands bonded to the tantalum via nitrogen, oxygen, and / or carbon. In some embodiments, the tantalum precursor is not a halide. In some embodiments, the tantalum precursor does not contain a halogen. In some embodiments, the ligands may comprise one or more of an alkoxo, amidinate, and / or pyrazolate group.

[0056] In some embodiments, the tantalum halide can include at least one of tantalum chloride, tantalum iodide, tantalum bromide, and tantalum fluoride. In some embodiments, the tantalum chloride can include tantalum pentachloride (TaCl5). In some embodiments, the tantalum iodide can include tantalum pentaiodide (TaI5). In some embodiments, the tantalum bromide can include tantalum pentabromide (TaBr5). In some embodiments, the tantalum fluoride can include tantalum pentafluoride (TaF5). Suitable tantalum halide precursors can be selected from any combination or subset of the exemplary tantalum halide precursors listed above.

[0057] As specific examples, tantalum precursors include pentakis(dimethylamido)tantalum (Ta(NMe)2)5), pentakis(diethylamido)tantalum (Ta(NEt)2)5), tris(diethylamido)(tert-butylimido)tantalum (Ta(N t Bu)(NEt2)3), tris(dimethylamido)(tert-butylimido)tantalum (Ta(N t Bu)(NMe2)3), tris(ethylmethylamido)(tert-butylimido)tantalum (Ta(N t Bu)(NEtMe)3), tris(diethylamido)(ethylimido)tantalum (Ta(NEt)(NEt2)3), tris(dimethylamido)(tert-amylimido)tantalum (Ta(N t Amyl)(NMe2)3), bis(diethylamido)cyclopentadienyl(tert-butylimido)tantalum (TaCp(N t Bu)(NEt2)2), (dimethylamido)bis(N,N'-isopropylacetamidinato)(tert-butylimido)tantalum (Ta(N t Bu)( i PrAMD)2(NMe2)), (tert-butylimido)tris(3,5-di-tert-butylpyrazolate)tantalum (Ta(N t Bu)( t Bu2pz)3), (isopropylimido)tris(tert-butoxy)tantalum (Ta(Ni Pr)(O t Bu)3), and (tert-butylimido)tris(tert-butoxy)tantalum (Ta(N t Bu)(O t The tantalum precursor may be or may include one or more of tantalum pentachloride (TaCl), tantalum pentaiodide (TaI), tantalum pentabromide (TaBr), and tantalum pentaethoxide (Ta(OEt)). Other suitable compounds include varying the alkyl substituents in the amide or imide ligands of any of the above compounds. Suitable tantalum precursors may be selected from any combination or subset (e.g., one or more, two or more, etc.) of the above exemplary tantalum precursors.

[0058] The niobium precursor can be or include one or more of a niobium metallo-organic compound, a niobium organometallic compound, and a niobium halide compound. According to exemplary embodiments, the niobium precursor includes one or more of nitrogen coordination compounds, such as amides, imides, and amidinates. In some embodiments, the niobium metallo-organic precursor includes amide ligands (e.g., Nb(NEtMe)5 and Nb(NMe2)5) and imide ligands (e.g., both types of ligands, such as Nb(N tBu)(NEt2)3). In some embodiments, the niobium precursor comprises a heteroleptic compound. The heteroleptic compound can include Cp and a halogen, such as chloride, or Cp and an alkylamine, or an amide and a halogen, such as chloride. In another embodiment, the niobium precursor comprises a homoleptic compound. As described herein, in some embodiments, the niobium halide precursor can include at least one halogen ligand, while the remaining ligands, such as metallo-organic or organometallic ligands, are different. In some embodiments, the niobium halide precursor can include one, two, three, four, or five halide ligands. In some embodiments, the niobium metallo-organic precursor can include at least one of a niobium alkylamide precursor, a niobium cyclopentadienyl ligand-containing precursor, or other metallo-organic niobium precursor. In some embodiments of the present disclosure, the niobium precursor includes one or more bidentate ligands bonded to the niobium through nitrogen and / or oxygen atoms. In some embodiments, the niobium precursor comprises one or more ligands bonded to the niobium through nitrogen, oxygen, and / or carbon. In some embodiments, the niobium precursor is not a halide. In some embodiments, the niobium precursor does not contain a halogen. In some embodiments, the ligands may comprise one or more of an alkoxo, amidinate, and / or pyrazolate group.

[0059] In some embodiments, the niobium halide precursor may include at least one of niobium chloride, niobium iodide, niobium bromide, and niobium fluoride. In some embodiments, the niobium chloride may include niobium pentachloride (NbCl). In some embodiments, the niobium iodide may include niobium pentaiodide (NbI). In some embodiments, the niobium bromide may include niobium pentabromide (NbBr). In some embodiments, the niobium fluoride may include niobium pentafluoride (NbF). Suitable niobium halide precursors may be selected from any combination or subset of the exemplary niobium halide precursors listed above.

[0060] As specific examples, niobium precursors include tetrakis(2,2,6,6-tetramethylheptane-3,5-dionato)niobium (Nb(thd)), pentakis(dimethylamido)niobium (Nb(NMe)), pentakis(diethylamido)niobium (Nb(NEt)), tris(diethylamido)(tert-butylimido)niobium (Nb(N t BU)(NEt2)3), tris(dimethylamido)(tert-butylimido)niobium (Nb(N t Bu)(NMe2)3), tris(ethylmethylamido)(tert-butylimido)niobium (Nb(N t BU)(NEtMe)3), (tert-amyrimido)tris(tert-butoxy)niobium (Nb(N t Amyl)(O t The niobium precursor may be or include one or more of niobium pentafluoride (NbF), niobium pentachloride (NbCl), niobium pentiodide (NbI), niobium pentabromide (NbBr), or niobium pentaethoxide (Nb(OEt)). Other suitable compounds include varying the alkyl substituents in the amido or imido ligands of any of the above compounds. Suitable niobium precursors may be selected from any combination or subset of the above exemplary niobium precursors.

[0061] The vanadium precursor can be or can include one or more of a vanadium metallo-organic compound, a vanadium organometallic compound, and a vanadium halide compound. According to exemplary embodiments, the vanadium precursor includes one or more nitrogen coordination compounds, such as amides, imides, and amidinates. In some embodiments, the vanadium metallo-organic precursor includes one or more amide and amido ligands (e.g., both types of ligands). In some embodiments, the vanadium precursor includes a heteroleptic compound. The heteroleptic compound can include Cp and a halogen, such as chloride, or Cp and an alkylamine, or an halogen, such as chloride. In another embodiment, the vanadium precursor includes a homoleptic compound. As described herein, in some embodiments, the vanadium halide precursor can include at least one halogen ligand, while the remaining ligands, such as metallo-organic or organometallic ligands, are different. In some embodiments, the vanadium halide precursor can include one, two, three, four, or five halide ligands. In some embodiments, the vanadium metalorganic precursor can include at least one of a vanadium alkylamide precursor, a vanadium cyclopentadienyl ligand-containing precursor, or other metalorganic vanadium precursor. In some embodiments of the present disclosure, the vanadium precursor includes one or more bidentate ligands bonded to the vanadium through nitrogen and / or oxygen atoms. In some embodiments, the vanadium precursor includes one or more ligands bonded to the vanadium through nitrogen, oxygen, and / or carbon. In some embodiments, the vanadium precursor is not a halide. In some embodiments, the vanadium precursor does not include a halogen. In some embodiments, the ligand can include one or more alkoxo, amidinate, and / or pyrazolate groups.

[0062] In some embodiments, the vanadium halide precursor can include at least one of vanadium chloride, niobium iodide, and vanadium bromide. In some embodiments, the vanadium chloride can include vanadium tetrachloride (VCl4). In some embodiments, the vanadium iodide can include vanadium triiodide (VI3). In some embodiments, the vanadium bromide can include vanadium tribromide (VBr3). In some embodiments, the vanadium fluoride can include vanadium pentafluoride (VF5). Suitable vanadium halide precursors can be selected from any subset of the exemplary vanadium halide precursors described above.

[0063] As specific examples, vanadium precursors include tetrakis(ethylmethylamido)vanadium (V(NEtMe)4), tetrakis(dimethylamido)vanadium (V(NMe2)4), tetrakis(diethylamido)vanadium (V(NEt2)4), tris(N,N'-diisopropylacetamidinato)vanadium (V( i The vanadium precursor may be or may include one or more of vanadium tris(acetylacetonato)vanadium (V(acac)), vanadium pentafluoride (VF), and vanadium tetrachloride (VCl). Other suitable compounds include varying the alkyl substituents in the amide or imide ligands of any of the above compounds. Suitable vanadium precursors may be selected from any subset of the exemplary vanadium precursors listed above.

[0064] In some embodiments, step 104 includes pulsing the Group 5 precursor in the reaction chamber for between about 0.01 seconds and about 60 seconds, between about 0.05 seconds and about 10 seconds, or between about 0.1 seconds and about 5.0 seconds. Further, during pulsing of the Group 5 precursor in the reaction chamber, the flow rate of the Group 5 precursor can be less than 2000 sccm, or less than 500 sccm, or even less than 100 sccm, or between about 1 and about 2000 sccm, between about 5 and about 1000 sccm, or between about 10 and about 500 sccm.

[0065] According to some embodiments of the present disclosure, etching of material can occur during step 104, particularly when the Group 5 precursor includes a metal halide. The amount of etching can be manipulated by controlling one or more of the temperature, pressure, flow rate, precursor dose, and selection / composition of the Group 5 precursor.

[0066] In some embodiments, the purity of the Group 5 precursor can affect the composition of the deposited film, and therefore a high purity source of the Group 5 precursor can be utilized. For example, in some embodiments, the Group 5 precursor can include a Group 5 precursor having a purity of 99.99% or greater.

[0067] In some embodiments, the Group 5 precursor may be contained in a container, and one or more heaters may be associated with the container to control the temperature of the Group 5 precursor, and subsequently the partial pressure of the Group 5 precursor. In some embodiments of the present disclosure, the Group 5 precursor in the container may be heated to a temperature of about 20° C. to about 300° C. For example, in some embodiments, the Group 5 precursor may be heated to a temperature of about 30° C. to about 250° C., or about 40° C. to about 225° C., or about 50° C. to about 150° C., depending on the precursor.

[0068] In some embodiments, the vessel containing the Group 5 precursor can be connected to one or more sources of carrier gas. The carrier gas can be introduced into the vessel and drawn over the surface of the metal precursor contained within the vessel, or can be blown through the metal precursor. The resulting evaporation of the Group 5 precursor entrains the Group 5 precursor vapor into the carrier gas, thereby distributing the Group 5 precursor to the reaction chamber.

[0069] In some embodiments, in addition to utilizing a high-purity Group 5 precursor, the carrier gas can be further purified to remove unwanted impurities. Accordingly, some embodiments of the present disclosure can further include flowing the carrier gas through a vessel containing a source of Group 5 precursor to transport the Group 5 precursor to the reaction chamber. Another embodiment of the present disclosure can include flowing the carrier gas through a gas purifier before entering the source of Group 5 precursor to reduce the concentration of at least one of water and oxygen in the carrier gas.

[0070] In some embodiments, the moisture concentration in the carrier gas can be reduced to less than 10 ppm, or less than 1 ppm, or less than 100 ppb, or less than 10 ppb, or less than 1 ppb, or even less than 100 ppt.

[0071] In some embodiments, the oxygen concentration in the carrier gas can be reduced to less than 10 ppm, or 1 ppm, or less than 100 ppb, or less than 10 ppb, or less than 1 ppb, or even less than 100 ppt.

[0072] In some embodiments, the hydrogen (H) concentration in the carrier gas can be reduced to less than 100 ppt. In some embodiments, the carbon dioxide (CO) concentration in the carrier gas can be reduced to less than 100 ppt. In some embodiments, the carbon monoxide (CO) concentration in the carrier gas can be reduced to less than 100 ppt.

[0073] In some embodiments, the carrier gas may include nitrogen gas (N2), and the carrier gas purifier may comprise a nitrogen gas purifier.

[0074] In some embodiments of the present disclosure, the Group 5 precursor can be fed through a gas purifier before entering the reaction chamber to reduce the concentration of at least one of water or oxygen in the Group 5 precursor.

[0075] In some embodiments, the water concentration in the Group 5 precursor can be reduced to less than 1 atomic %, or less than 1000 ppm, or less than 100 ppm, or less than 10 ppm, or less than 1 ppm, or less than 100 ppb, or even less than 100 ppt.

[0076] In some embodiments, the oxygen concentration in the Group 5 precursor can be reduced to less than 1 atomic %, or less than 1000 ppm, or less than 100 ppm, or less than 10 ppm, or less than 1 ppm, or less than 100 ppb, or even less than 100 ppt.

[0077] Without being bound by any theory or mechanism, it is believed that reducing at least one of the water and oxygen concentrations in the carrier gas and / or Group 5 precursor allows for the deposition of Group 5 chalcogenide films of desired composition while preventing the deposition of oxide phases at the desired deposition temperature.

[0078] As part of step 104, the reaction chamber is purged using vacuum and / or one or more of an inert gas, such as argon (Ar) and nitrogen (N), to mitigate gas-phase reactions between reactants and allow self-saturating surface reactions, e.g., in the case of ALD. Additionally or alternatively, the substrate can be moved to separately contact a first gas-phase reactant with a second gas-phase reactant. Any excess chemicals and reaction by-products can be removed from the surface of the substrate before contacting the substrate with the next reactive chemical, e.g., by purging the reaction space or by moving the substrate (step 106).

[0079] For example, in some embodiments of the present disclosure, the method can include a purge cycle, in which the substrate surface is purged for less than about 5.0 seconds, or less than about 2.0 seconds, or even less than about 1.0 second. In some embodiments, the substrate surface is purged for about 0.01 seconds to about 60 seconds, or about 0.05 seconds to about 10 seconds, or about 0.1 seconds to about 5 seconds. Excess Group 5 precursor and any reaction by-products can be removed using a vacuum generated by an exhaust system.

[0080] Step 106 includes providing a chalcogen reactant into the reaction chamber. Any number of chalcogen reactants can be used in the cyclic deposition processes disclosed herein. In some embodiments, the chalcogen reactant is selected from the following list: H2S, H2Se, H2Te, (CH3)2S, (NH4)2S, dimethyl sulfoxide ((CH3)2SO), (CH3)2Se, (CH3)2Te, elemental or atomic S, Se, Te, other precursors containing chalcogen-hydrogen bonds, such as H2S2, H2Se2, H2Te2, or a chalcogenol having the formula R-Y-H, where R can be a substituted or unsubstituted hydrocarbon, preferably a C1-C8 alkyl or substituted alkyl, such as an alkylsilyl group, more preferably a linear or branched C1-C5 alkyl group, and Y can be S, Se, or Te. In some embodiments, the chalcogen reactant is a thiol having the formula R—S—H, where R can be a substituted or unsubstituted hydrocarbon, preferably a C1-C8 alkyl group, more preferably a straight or branched C1-C5 alkyl group. In some embodiments, the chalcogen reactant has the formula (RSi)Y, where Rsi is an alkylsilyl group and Y can be S, Se, or Te. In some embodiments, the chalcogen reactant includes S or Se. In some embodiments, the chalcogen precursor includes S. In some embodiments, the chalcogen precursor does not include S. In some embodiments, the chalcogen precursor may include a chalcogen element, for example, elemental sulfur. In some embodiments, the chalcogen precursor includes Te. In some embodiments, the chalcogen precursor does not include Te. In some embodiments, the chalcogen precursor includes Se. In some embodiments, the chalcogen precursor does not include Se. In some embodiments, the chalcogen precursor is selected from precursors including S, Se, and Te. In some embodiments, the chalcogen precursor is H2S n, where n is 4 to 10. By way of example, the chalcogen reactant can include one or more of the following reactants, which can include hydrogen sulfide (HS), hydrogen selenide (HSe), dimethyl sulfide ((CH)S), tert-butyl thiol ((CH)CSH), and / or 2-methylpropane-2-thiol, and dimethyl telluride ((CH)Te).

[0081] In some embodiments, suitable chalcogen reactants can include many chalcogen-containing compounds. In some embodiments, the chalcogen reactant can include at least one chalcogen-hydrogen bond. In some embodiments, the chalcogen precursor can include chalcogen plasma, chalcogen atoms, or chalcogen radicals. In some embodiments where an excited chalcogen reactant is desired, a plasma can be generated within the reaction chamber or upstream of the reaction chamber. In some embodiments, the chalcogen reactant does not include an excited chalcogen precursor, e.g., a plasma, atoms, or radicals. In some embodiments, the chalcogen reactant can include a chalcogen reactant containing a chalcogen-hydrogen bond, e.g., a chalcogen plasma, chalcogen atoms, or chalcogen radicals formed from H2S. In some embodiments, the chalcogen reactant can include a chalcogen plasma, chalcogen atoms, or chalcogen radicals, e.g., a plasma containing sulfur, selenium, or tellurium, preferably a sulfur-containing plasma. In some embodiments, the plasma, atoms, or radicals include tellurium. In some embodiments, the plasma, atoms, or radicals include selenium. In some embodiments, the chalcogen precursor does not include a tellurium precursor.

[0082] In some embodiments, the purity of the chalcogen reactant can affect the composition of the deposited film, and therefore, high purity sources of chalcogen-containing gas-phase reactants may be utilized. In some embodiments, the chalcogen reactant can have a purity of 99.5% or greater. As a non-limiting example, the chalcogen reactant may include hydrogen sulfide (HS) of 99.5% or greater purity.

[0083] In some embodiments, in addition to utilizing a high-purity chalcogen reactant, the chalcogen precursor gas can be further purified to remove unwanted impurities. Accordingly, some embodiments of the present disclosure may further include flowing the chalcogen reactant through a gas purifier before entering the reaction chamber to reduce the concentration of at least one of water or oxygen in the chalcogen-containing gas-phase reactant.

[0084] In some embodiments, the water or oxygen concentration in the chalcogen reactant can be reduced to less than 5 atomic %, or less than 1 atomic %, or less than 1000 ppm, or less than 100 ppm, or less than 10 ppm, or less than 1 ppm, or less than 100 ppb, or less than 10 ppb, or even less than 1 ppb.

[0085] Without being bound by any theory or mechanism, it is believed that reducing the water concentration and / or oxygen concentration in the chalcogen reactant allows for the deposition of Group 5 chalcogenide films of desired composition while preventing the deposition of Group 5 oxide phases at the desired deposition temperature.

[0086] Step 106 can include a purge that can be the same as or similar to the purge associated with step 104 above.

[0087] Steps 104 and 106 can comprise one unit deposition cycle, for example, a unit deposition cycle can include delivering a Group 5 precursor into the reaction chamber, purging the reaction chamber, delivering a chalcogen reactant into the reaction chamber, and purging the reaction chamber again.

[0088] In some embodiments of the present disclosure, method 100 includes repeating the unit deposition cycle one or more times, for example, based on the desired thickness of the Group 5 chalcogenide. For example, if the thickness of the Group 5 chalcogenide film is insufficient for a desired application, steps 104 and 106 of method 100 may be repeated one or more times. Once the Group 5 chalcogenide film is deposited to the desired thickness (step 108), exemplary method 100 may end, and the Group 5 chalcogenide film may be subjected to another process to form a device structure.

[0089] Although not specifically illustrated, in some embodiments of the present disclosure, a layer including a Group 5 chalcogenide may undergo a post-deposition annealing process to improve the crystallinity of the layer. For example, in some embodiments, a method, e.g., method 100, further includes post-deposition annealing of the Group 5 chalcogenide, e.g., at a temperature higher than the deposition temperature of the Group 5 chalcogenide film. For example, in some embodiments, annealing the Group 5 chalcogenide may include heating the Group 5 chalcogenide film to a temperature less than about 800°C, or less than about 600°C, or less than about 500°C, or even less than about 400°C. In some embodiments, post-deposition annealing of the Group 5 chalcogenide thin film may be performed in a chalcogen-containing atmosphere. For example, the post-deposition annealing process may be performed in an atmosphere including a chalcogenide compound, e.g., a sulfur compound, e.g., a hydrogen sulfide (HS) atmosphere. In some embodiments, post-deposition annealing of Group 5 chalcogenide thin films can be performed for less than 1 hour, or less than 30 minutes, or less than 15 minutes, or even less than 5 minutes. In some embodiments, post-deposition annealing of Group 5 chalcogenide thin films may be performed in an atmosphere that does not contain any chalcogens, such as S, Se, and Te, for example, in an inert gas atmosphere, such as N, or a noble gas, such as Ar or He, or in a hydrogen-containing atmosphere, such as H or H / N.

[0090] It should be understood that in some embodiments of the present disclosure, the order in which the substrate is contacted with the Group 5 precursor and the chalcogen reactant may be such that the substrate is first contacted with the chalcogen reactant and then with the Group 5 precursor. Furthermore, in some embodiments, the cyclic deposition process may include contacting the substrate one or more times with a first gas-phase reactant (i.e., Group 5 precursor) before contacting the substrate one or more times with a second gas-phase reactant (i.e., chalcogen reactant), or similarly, contacting the substrate one or more times with a second gas-phase reactant before contacting the substrate one or more times with the first gas-phase reactant.

[0091] Additionally, some embodiments of the present disclosure may include non-plasma reactants, such as Group 5 precursors, where the chalcogen reactant is substantially free of ionized reactants. In some embodiments, the Group 5 precursor and the chalcogen reactant are substantially free of ionized reactants, excited species, and radical species. For example, both the Group 5 precursor and the chalcogen reactant may include non-plasma reactants to prevent ionization damage to the underlying substrate and the associated defects generated thereby.

[0092] In some embodiments, the growth rate of the Group 5 chalcogenide film is between about 0.005 Å / cycle and about 5 Å / cycle, or between about 0.01 Å / cycle and about 2.0 Å / cycle. In some embodiments, the film growth rate is greater than about 0.05 Å / cycle, or greater than about 0.1 Å / cycle, or greater than about 0.15 Å / cycle, or greater than about 0.20 Å / cycle, or greater than about 0.25 Å / cycle, or even greater than about 0.3 Å / cycle. In some embodiments, the film growth rate is less than about 2.0 Å / cycle, or less than about 1.0 Å / cycle, or less than about 0.75 Å / cycle, or less than about 0.5 Å / cycle, or less than 0.2 Å / cycle.

[0093] In some embodiments of the present disclosure, Group 5 chalcogenides deposited according to the methods disclosed herein may include a protective capping layer that substantially prevents or even prevents undesired oxidation of the Group 5 chalcogenide film. For example, once deposition of the Group 5 chalcogenide is complete, the chalcogenide film may be removed from the reaction chamber and exposed to atmospheric conditions where oxygen and / or water in the surrounding environment can oxidize the deposited Group 5 chalcogenide.

[0094] Thus, in some embodiments, the capping layer can be deposited on the Group 5 chalcogenide film, specifically, directly on the Group 5 chalcogenide film. Furthermore, to prevent any potential oxidation of the Group 5 chalcogenide film, the capping layer can be deposited in the same reaction chamber utilized to deposit the Group 5 chalcogenide, i.e., the capping layer can be deposited in situ in the same reaction chamber utilized to deposit the Group 5 chalcogenide film. Thus, in some embodiments of the present disclosure, the method can further include depositing the capping layer in situ on the Group 5 chalcogenide film to substantially prevent oxidation of the Group 5 chalcogenide film when exposed to ambient conditions. In some embodiments, the capping layer is deposited using a non-oxidizing process or a process that does not use an oxygen source, such as HO, O, HO, O, and oxygen plasma, radicals, or excited species.

[0095] In some embodiments, the capping layer may comprise a metal silicate film. In some embodiments, the metal silicate film is aluminum silicate (Al x Si y O x ), hafnium silicate (Hf x Si y O x ), or zirconium silicate (Zr x Si y O x ) More detailed information regarding the deposition of metal silicate films is provided in U.S. Patent No. 6,632,279, filed October 13, 2000, entitled "METHOD FOR GROWING THIN OXIDE FILMS," the contents of which are incorporated herein by reference.

[0096] As previously described herein, in some embodiments, the capping layer can be deposited directly on the Group 5 chalcogenide film by a cyclic deposition process, such as an atomic layer deposition process or a cyclic chemical vapor deposition process. For example, and without limitation, the capping layer can include a metal silicate, which can be deposited by a cyclic deposition process, such as atomic layer deposition. In some embodiments, the capping layer can be deposited using a process including a non-oxidizing reactant / precursor or a process including a non-oxygen reactant (e.g., without O2, HO, O3, HO2, O-containing plasma, oxygen radicals, or oxygen atoms). Thus, in some embodiments, the capping layer can be deposited without the use of HO, O3, or HO2. In some embodiments, the capping layer can be deposited without the use of an oxygen-based plasma, i.e., without the use of an O-containing plasma, oxygen radicals, oxygen atoms, or oxygen excited species. The capping layer can be deposited using a process that includes non-oxidizing reactants / precursors or non-oxygen reactants to prevent or substantially prevent oxidation of the underlying Group 5 chalcogenide film. Thus, in some embodiments, in situ deposition of a capping layer on a Group 5 chalcogenide film can be performed without further oxidation of the Group 5 chalcogenide film.

[0097] In other embodiments, the capping layer can comprise a metal, such as a Group 5 metal. In some embodiments, the capping layer can comprise a nitride, a sulfide, a carbide, or a mixture thereof, or a silicon-containing layer, such as an amorphous silicon layer. In other embodiments, the capping layer can be a dielectric layer. In other embodiments, the capping layer can be a conductive layer. In other embodiments, the capping layer can be a semiconductor layer.

[0098] An exemplary ALD process for depositing a capping layer can include one or more repeated unit deposition cycles, where a unit deposition cycle can include contacting a substrate with a metal vapor-phase reactant, purging the reaction chamber of excess metal precursor and reaction by-products, contacting the substrate with a precursor containing both silicon and oxygen components, and purging the reaction chamber a second time. As a non-limiting example, the capping layer can be an aluminum silicate film (Al x Si y O z ), and the metal vapor-phase reactant may include aluminum trichloride (AlCl3). Meanwhile, a precursor containing both silicon and oxygen components may be tetra-n-butoxysilane Si(O n In some embodiments of the present disclosure, the capping layer may comprise a metal silicate deposited without the use of an oxidizing precursor, such as O, HO, O, HO, O-containing plasma, oxygen radicals, and oxygen atoms.

[0099] In some embodiments, the capping layer can be deposited at the same temperature utilized to deposit the Group 5 chalcogenide film. For example, the capping layer can be deposited at a temperature of less than 500° C., or less than 450° C., or less than 400° C., or less than 300° C., or less than 200° C. In some embodiments, the capping layer can be deposited at a temperature between about 200° C. and 500° C., specifically at a deposition temperature of about 400° C.

[0100] In some embodiments, the capping layer may be deposited to a thickness of less than 50 nanometers, or less than 40 nanometers, or less than 30 nanometers, or less than 20 nanometers, or less than 10 nanometers, or less than 7 nanometers, or less than 5 nanometers, or less than 3 nanometers, or less than 2 nanometers, or even less than 1 nanometer. In some embodiments, the capping layer is a continuous film and is disposed directly on the metal chalcogenide film to substantially prevent oxidation of the metal chalcogenide film.

[0101] According to yet another embodiment, a seed layer can be deposited prior to depositing a layer comprising a Group 5 chalcogenide. For example, a sacrificial layer comprising, for example, silicon can be deposited (e.g., on a silicon oxide layer). Such a sacrificial layer can be particularly useful with highly reactive precursors, such as Group 5 fluoride precursors.

[0102] According to yet another embodiment of the present disclosure, a metal or metal layer can be deposited on the Group 5 chalcogenide and / or capping layer (if present). By way of example, the metal layer can include a 3D metal, such as a transition metal, e.g., gold, tungsten, a metal nitride or transition metal nitride, e.g., TiN, a metal carbide, a metal alloy, and mixtures thereof.

[0103] 2 illustrates a structure 200 according to another embodiment of the present disclosure. The structure 200 comprises a substrate 202 and a layer comprising a Group 5 chalcogenide 204 overlying the substrate. The structure according to the present disclosure may further comprise a capping layer, a metal layer, or other suitable layer.

[0104] According to some embodiments of the present disclosure, the Group 5 chalcogenide-containing layer 204 includes a Group 5 disulfide. Furthermore, in some embodiments, the Group 5 chalcogenide-containing layer 204 may be crystalline, having a composition that includes a 2D disulfide. The Group 5 disulfide may be metallic.

[0105] A Group 5 chalcogenide-containing layer 204 can be deposited according to method 100. According to some embodiments of the present disclosure, the Group 5 chalcogenide-containing layer 204 can be a continuous film comprising a 2D material. In some embodiments, a Group 5 chalcogenide-containing film deposited according to some embodiments of the present disclosure can be continuous with a thickness of less than about 100 nanometers, or less than about 60 nanometers, or less than about 50 nanometers, or less than about 40 nanometers, or less than about 30 nanometers, or less than about 25 nanometers, or less than about 20 nanometers, or less than about 15 nanometers, or less than about 10 nanometers, or less than about 5 nanometers.

[0106] In some embodiments, Group 5 chalcogenide films deposited according to embodiments of the present disclosure can be continuous on substrates having diameters greater than 100 millimeters, or greater than 200 millimeters, or greater than 300 millimeters, or even greater than 400 millimeters. Continuity referred to herein can be physical continuity or electrical continuity. In some embodiments, the thickness at which a film can be physically continuous may not be the same as the thickness at which the film is electrically continuous.

[0107] In some embodiments of the present disclosure, the Group 5 chalcogenide films deposited by the methods disclosed herein can include at least one of tantalum sulfide, tantalum selenide, tantalum telluride, niobium sulfide, niobium selenide, niobium telluride, vanadium sulfide, vanadium selenide, and vanadium telluride.

[0108] In some embodiments of the present disclosure, the Group 5 chalcogenides deposited by the methods disclosed herein have the general formula MS xwhere M is Ta, Nb, or V, and x can range from about 0.75 to about 2.8, or where x can range from about 0.8 to about 2.5, or where x can range from about 0.9 to about 2.3, or where x can range from about 0.95 to about 2.2. x The elemental composition range of may include about 30 atomic % to about 60 atomic %, or about 35 atomic % to about 55 atomic %, or even about 40 atomic % to about 50 atomic % Ta, Nb, and / or V. Alternatively, MS x The elemental composition range can include about 25 atomic % to about 75 atomic % S, or about 30 atomic % to about 60 atomic % S, or even about 35 atomic % to about 55 atomic % S.

[0109] In other embodiments, the Group 5 chalcogenides of the present disclosure can contain less than about 20 atomic percent oxygen, or less than about 10 atomic percent oxygen, or less than about 5 atomic percent oxygen, or even less than about 2 atomic percent oxygen. In other embodiments, the Group 5 chalcogenides can contain less than about 25 atomic percent hydrogen, or less than about 10 atomic percent hydrogen, or less than about 5 atomic percent hydrogen, or less than about 2 atomic percent hydrogen, or even less than about 1 atomic percent hydrogen. In yet other embodiments, the Group 5 chalcogenides can contain less than about 20 atomic percent carbon, or less than about 10 atomic percent carbon, or less than about 5 atomic percent carbon, or less than about 2 atomic percent carbon, or less than about 1 atomic percent carbon, or even less than about 0.5 atomic percent carbon. In the embodiments outlined herein, the atomic concentrations of elements can be measured using Rutherford backscattering (RBS) and / or elastic recoil detection analysis (ERDA).

[0110] In some embodiments of the present disclosure, Group 5 chalcogenides may be deposited on three-dimensional structures. In some embodiments, the step coverage of the Group 5 chalcogenides can be about 50% or greater, or about 80% or greater, or about 90% or greater, or about 95%, or about 98%, or about 99% or greater in structures with aspect ratios (height / width) greater than about 2, greater than about 5, greater than about 10, greater than about 25, greater than about 50, or even greater than about 100.

[0111] In some embodiments, the Group 5 chalcogenides of the present disclosure, such as Ta, Nb, and / or V dichalcogenides, can be deposited to a thickness of about 20 nanometers to about 100 nanometers. In some embodiments, the Group 5 chalcogenide thin films deposited according to some of the embodiments described herein can have a thickness of about 20 nanometers to about 60 nanometers. In some embodiments, the Group 5 chalcogenide thin films deposited according to some of the embodiments described herein can have a thickness of greater than about 20 nanometers, or greater than about 30 nanometers, or greater than about 40 nanometers, or greater than about 50 nanometers, or greater than about 60 nanometers, or greater than about 100 nanometers, or greater than about 250 nanometers, or greater than about 500 nanometers, or even greater. In some embodiments, Group 5 chalcogenide thin films deposited according to some of the embodiments described herein can have a thickness of less than about 50 nanometers, or less than about 30 nanometers, or less than about 20 nanometers, or less than about 15 nanometers, or less than about 10 nanometers, or less than about 5 nanometers, or less than about 3 nanometers, or less than about 2 nanometers, or less than about 1.5 nanometers, or even less than about 1 nanometer.

[0112] In some embodiments, Group 5 chalcogenide films, such as Ta, Nb, and / or V dichalcogenide films deposited according to some of the embodiments described herein, can have a thickness of no more than about 10 monolayers of Group 5 chalcogenide material, or no more than about 7 monolayers of Group 5 chalcogenide material, or no more than about 5 monolayers of Group 5 chalcogenide material, or no more than about 4 monolayers of Group 5 chalcogenide material, or no more than about 3 monolayers of Group 5 chalcogenide material, or no more than about 2 monolayers of Group 5 chalcogenide material, or even no more than about 1 monolayer of Group 5 chalcogenide material.

[0113] The Group 5 metal chalcogenides and / or structures deposited by the (e.g., cyclic) deposition processes disclosed herein may be utilized in a variety of contexts, such as contact and / or conductive layers in semiconductor device structures, catalysts for water splitting, supercapacitors, batteries, low temperature superconductors, and devices that exhibit different charge density waves at different temperatures.

[0114] Embodiments of the present disclosure may also include a system configured to deposit the Group 5 chalcogenide films of the present disclosure. More specifically, FIG. 3 schematically illustrates a system 300 including a reaction chamber 302 that holds a substrate (e.g., a susceptor, not shown) under a predetermined pressure and temperature and further includes a mechanism for selectively exposing the substrate to various gases. The reaction chamber 302 may include any suitable reaction chamber, such as an ALD or CVD reaction chamber. A Group 5 precursor source 306 may be connected to the reaction chamber 302 by a conduit or other suitable means 306A and may further be connected to a manifold, valve control system, mass flow control system, or mechanism to control the gaseous precursor from the Group 5 precursor source 306. The precursors supplied by the Group 5 precursor source 306 can be liquid or solid under room temperature and standard atmospheric pressure conditions. Such precursors can be vaporized in a vacuum vessel of the reactant source, and the precursors can be maintained above the vaporization temperature in the precursor source chamber. In such embodiments, the vaporized precursor may be transported in a carrier gas (e.g., an inactive or inert gas) and delivered into the reaction chamber 302 through conduit 306A. In other embodiments, the Group 5 precursor may be gaseous under standard conditions. In such embodiments, the precursor does not need to be vaporized and does not require a carrier gas. For example, in one embodiment, the precursor may be stored in a gas cylinder. The Group 5 precursor may include one or more Group 5 precursors (individually or mixed), such as one or more of the Group 5 precursors listed above. Conduit 306A may further include a gas purifier 305B for substantially removing undesired contaminants from the vapor delivered to the reaction chamber 302.

[0115] System 300 may also include a chalcogen reactant source 304, which may be coupled to reaction chamber 302 by a conduit 304A and another gas purifier 305A, which may be the same as or similar to the corresponding components described above. Chalcogen reactant source 304 may include one or more chalcogen reactants (individually or mixed), such as one or more of the chalcogen reactants described above. The chalcogen reactant may be supplied to reaction chamber 302 with or without the aid of a carrier gas.

[0116] A purge gas source 308 can also be coupled to the reaction chamber 302 via conduit 308A. The purge gas source 308 can also selectively supply various inert or noble gases to the reaction chamber 302 to assist in removing precursor or waste gases from the reaction chamber 302. The inert or noble gases can come from solid, liquid, or stored gaseous form.

[0117] A vacuum source 314, such as a vacuum pump, can be used to maintain a desired pressure within the reaction chamber 302. Additionally or alternatively, the vacuum source 314 can be used to easily purge the reaction chamber 302.

[0118] The system 300 may also include a system operation and control mechanism 310, which provides electronic circuitry and mechanical components for selectively operating the valves, manifolds, pumps, and other devices included in the system 300. Such circuits and components operate to introduce precursor and purge gases from the respective precursor sources 304, 306, and purge gas source 308. The system operation and control mechanism 310 may also control the timing of gas pulse sequences, substrate and reaction chamber temperatures, and reaction chamber pressure, as well as various other operations for proper operation of the reaction system 300. The operation and control mechanism 310 may include control software and electrical or pneumatic control valves for controlling the flow of precursor, reactant, and purge gases into and out of the reaction chamber 302. The control system may include software or hardware components, such as modules, such as FPGAs or ASICs, that perform specific tasks. The modules may advantageously be configured to reside on addressable storage media in the control system and may be configured to perform one or more processes. For example, the operation and control mechanism 310 can control gas flow rates, reaction chamber pressure, reaction chamber and / or susceptor temperature, etc., as described above.

[0119] Other configurations of the system are possible, including different numbers and types of precursor and reactant sources and purge gas sources. It will be appreciated that there are numerous arrangements of valves, conduits, precursor sources, and purge gas sources that can be used to achieve the goal of selectively delivering gases into the reaction chamber 302. Furthermore, as a schematic representation of the system, many components have been omitted for ease of illustration. Such components may include, for example, various valves, manifolds, purifiers, heaters, reservoirs, vents, and / or bypasses.

[0120] The exemplary embodiments of the present disclosure described above are merely examples of embodiments of the present invention, as defined by the appended claims and their legal equivalents, and therefore do not limit the scope of the present invention. Any equivalent embodiments are intended to be within the scope of the present invention. Indeed, various modifications of the present disclosure in addition to those shown and described herein may become apparent to those skilled in the art from the description, including alternative useful combinations of the described elements. Such modifications and embodiments are also intended to be included within the scope of the appended claims.

Claims

1. 1. A method of forming a structure, comprising: providing a substrate into a reaction chamber; providing a Group 5 precursor into the reaction chamber; providing a chalcogen reactant into the reaction chamber; forming a two-dimensional Group 5 chalcogenide-containing layer on the substrate using chemical vapor deposition or atomic layer deposition; forming a capping layer directly on the two-dimensional Group 5 chalcogenide-containing layer using chemical vapor deposition or atomic layer deposition; The Group 5 precursors include heteroleptic compounds containing amide and imido ligands; the Group 5 precursor comprises one or more of a tantalum precursor, a niobium precursor, and a vanadium precursor; The method, wherein the chalcogen reactant comprises one or more of a sulfur reactant, a selenium reactant, and a tellurium reactant.

2. 1. A method of forming a structure, comprising: providing a substrate into a reaction chamber; providing a Group 5 precursor into the reaction chamber; providing a chalcogen reactant into the reaction chamber; forming a layer comprising a metallic two-dimensional Group 5 chalcogenide on the substrate using chemical vapor deposition or atomic layer deposition; forming a capping layer directly on the two-dimensional Group 5 chalcogenide-containing layer using chemical vapor deposition or atomic layer deposition; The Group 5 precursors include heteroleptic compounds containing amide and imido ligands; the Group 5 precursor comprises one or more of a tantalum precursor, a niobium precursor, and a vanadium precursor; The method, wherein the chalcogen reactant comprises one or more of a sulfur reactant, a selenium reactant, and a tellurium reactant.

3. 3. The method of claim 1 or 2, further comprising purging the reaction chamber.

4. 4. The method of any one of claims 1 to 3, wherein the temperature in the reaction chamber is from about 50°C to about 500°C, from about 100°C to about 600°C, or from about 300°C to about 500°C.

5. The pressure in the reaction chamber is about 10 －７ ~ about 1000 mbar, about 10 －４ ~ about 100 mbar, about 10 －２ to about 50 mbar, or about 10 －１ The method according to any one of claims 1 to 4, wherein the pressure is from about 10 mbar to about 10 mbar.

6. 6. The method of claim 1, wherein the Group 5 precursor comprises a nitrogen coordination compound.

7. The tantalum precursor is tris(diethylamido)(tert-butylimido)tantalum (Ta(N ｔ Bu)(NEt ２ ) ３ ), tris(dimethylamido)(tert-butylimido)tantalum (Ta(N ｔ Bu)(NMe ２ ) ３ ), tris(ethylmethylamido)(tert-butylimido)tantalum (Ta(N ｔ Bu) (NEtMe) ３ ), tris(diethylamido)(ethylimido)tantalum (Ta(NEt)(NEt ２ ) ３ ), tris(dimethylamido)(tert-amylimido)tantalum (Ta(N ｔ Amyl)(NMe ２ ) ３ ), bis(diethylamido)cyclopentadienyl(tert-butylimido)tantalum (TaCp(N ｔ Bu)(NEt ２ ) ２ ), (dimethylamido)bis(N,N'-isopropylacetamidinato)(tert-butylimido)tantalum (Ta(N ｔ Bu) ( ｉ PrAMD) ２ (NMe ２ )), (tert-butylimido)tris(3,5-di-tert-butylpyrazolate)tantalum (Ta(N ｔ Bu) ( ｔ Bu ２ pz) ３ ), (isopropylimido)tris(tert-butoxy)tantalum (Ta(N ｉ Pr) (O ｔ Bu) ３ ), and (tert-butylimido)tris(tert-butoxy)tantalum (Ta(N ｔ Bu) (O ｔ Bu) ３ 6. The method of claim 1, further comprising one or more of the following:

8. The niobium precursor is pentakis(dimethylamido)niobium (Nb(NMe) ２ ) ５ ), pentakis(diethylamido)niobium (Nb(NEt) ２ ) ５ ), tris(diethylamido)(tert-butylimido)niobium (Nb(N ｔ BU) (NEt ２ ) ３ ), tris(dimethylamido)(tert-butylimido)niobium (Nb(N ｔ Bu)(NMe ２ ) ３ ), tris(ethylmethylamido)(tert-butylimido)niobium (Nb(N ｔ BU) (NEtMe) ３ ), and (tert-amirimido)tris(tert-butoxy)niobium (Nb(N ｔ Amyl) (O ｔ Bu) ３ 6. The method of claim 1, further comprising one or more of the following:

9. The vanadium precursor is tetrakis(ethylmethylamido)vanadium (V(NEtMe) ４ ), tetrakis(dimethylamido)vanadium (V(NMe ２ ) ４ ), and tetrakis(diethylamido)vanadium (V(NEt ２ ) ４ 6. The method of claim 1, further comprising one or more of the following:

10. The chalcogen reactant is H ２ S, H ２ Se, H ２ Te, (CH ３ ) ２ S, (NH ４ ) ２ S, dimethyl sulfoxide ((CH ３ ) ２ SO), (CH ３ ) ２ Se, (CH ３ ) ２ Te, element or atom S, element or atom Se, element or atom Te, H ２ S ２ , H ２ Se ２ , H ２ Te ２ , formula R-Y-H (wherein R is C １ ~C ８ a substituted or unsubstituted hydrocarbon selected from alkyl or substituted alkyl of the formula R—S—H, where R is a substituted or unsubstituted hydrocarbon; or a thiol having the formula R—S—H, where R is a substituted or unsubstituted hydrocarbon; ３ Si) ２ Y (wherein, R ３ 10. The method of claim 1, wherein Si is an alkylsilyl group and Y is S, Se, or Te.

11. 11. The method of claim 1, wherein the chalcogen reactant is exposed to one or more of a direct plasma and a remote plasma to form activated reactant species.

12. 12. The method of claim 1, wherein the Group 5 chalcogenide-containing layer comprises a dichalcogenide material.

13. 13. The method of any one of claims 1 to 12, further comprising an annealing step.

14. 14. The method of claim 13, wherein the temperature in the reaction chamber during the annealing step is less than 800°C, or less than 600°C, or less than 500°C, or less than 400°C, or from about 400°C to about 500°C.

15. 15. The method of any one of claims 1 to 14, further comprising etching the Group 5 chalcogenide layer with an etchant comprising a metal halide.

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