Method for depositing transition metal chalcogenide film on substrate by cyclic deposition process

Abstract

To provide a method for depositing a transition metal chalcogenide film on a substrate by a cyclic deposition process.SOLUTION: A method can includes steps of: bringing a substrate into contact with at least one transition metal-containing vapor-phase reaction material containing at least either of a hafnium precursor and a zirconium precursor; and bringing the substrate into contact with at least one chalcogen-containing vapor-phase reaction material. A semiconductor device structure including a transition metal chalcogenide film deposited by the disclosed method is also provided.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 was made as a result of activities undertaken within the scope of the Agreement.

[0002] The present disclosure relates generally to methods for depositing transition metal chalcogenide films on substrates by a cyclic deposition process, and specifically to cyclic deposition of transition metal chalcogenides including hafnium or zirconium. The present disclosure also relates to semiconductor device structures including transition metal chalcogenide films deposited by the cyclic deposition process. [Background technology]

[0003] Interest in two-dimensional (2D) materials has increased dramatically in recent years due to their potential to improve the performance of next-generation electronic devices. For example, graphene is the most studied 2D material to date, exhibiting high mobility, transmittance, mechanical strength, and flexibility. However, the lack of a band gap in pure graphene limits its performance in semiconductor device structures, e.g., transistors. Such limitations of graphene have stimulated the study of alternative 2D materials as graphene analogues. Recently, transition metal chalcogenides, specifically transition metal dichalcogenides, have attracted considerable research attention as alternatives to graphene. Transition metal dichalcogenides can have a stoichiometry of MX2, which represents a transition metal (M) sandwiched between two layers of chalcogen atoms (X), with strong in-plane covalent bonds between the metal chalcogens and weak out-of-plane van der Waals bonds between the layers.

[0004] However, there are few scalable low-temperature methods for fabricating 2D materials. Currently, mechanical exfoliation of bulk crystals is the most commonly used formation method, but although this method produces good quality crystals, the method cannot produce continuous films and is very labor intensive, making such methods unfeasible for industrial production. Chemical vapor deposition (CVD) has been used to deposit 2D materials, but current CVD processes for some metal chalcogenides, e.g., hafnium disulfide (HfS2), operate at temperatures between 900°C and 1000°C and are not capable of fabricating continuous, large-area 2D materials.

[0005] Therefore, methods that can fabricate 2D materials with atomic-level control over film thickness at reduced deposition temperatures are desirable. Summary of the Invention

[0006] 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 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.

[0007] In some embodiments, a method is provided for depositing a transition metal chalcogenide film on a substrate by a cyclic deposition process. The method may include contacting the substrate with at least one transition metal-containing gas phase reactant comprising at least one of a hafnium precursor or a zirconium precursor, and contacting the substrate with at least one chalcogen-containing gas phase reactant, wherein the temperature of the substrate during the contacting step is less than about 450° C.

[0008] Embodiments of the present disclosure also provide semiconductor device structures that include a transition metal chalcogenide film deposited by the methods described herein.

[0009] For purposes of summarizing the invention and the advantages achieved over the prior art, certain specific objects and advantages of the invention have been described hereinabove. Of course, it should be understood that not all such objects or advantages may be achieved by any particular embodiment of the invention. Thus, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages, for example, as taught or suggested herein, without necessarily achieving other objects or advantages that may be taught or suggested herein.

[0010] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will be readily apparent to those skilled in the art from the following detailed description of several embodiments, taken in conjunction with the accompanying drawings, and the invention is not limited to any particular embodiment disclosed. [Brief description of the drawings]

[0011] While the 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.

[0012] [Figure 1] FIG. 1 is a process flow diagram illustrating an exemplary cyclic deposition method according to an embodiment of the present disclosure.

[0013] [Diagram 2] FIG. 2 illustrates the growth rate, crystallinity, and composition of exemplary hafnium chalcogenide films deposited at various deposition temperatures according to an embodiment of the present disclosure.

[0014] [Diagram 3] FIG. 3 is a graph of the growth rate, crystallinity, and composition of exemplary zirconium chalcogenide films deposited at various deposition temperatures according to an embodiment of the present disclosure.

[0015] [Figure 4] FIG. 4 is grazing incidence x-ray diffraction (GIXRD) data for exemplary hafnium chalcogenide films deposited at various deposition temperatures according to embodiments of the present disclosure.

[0016] [Diagram 5] FIG. 5 is grazing incidence x-ray diffraction (GIXRD) data for exemplary zirconium chalcogenide films deposited at various deposition temperatures according to embodiments of the present disclosure.

[0017] [Figure 6] FIG. 6 is the environmental stability over time of both bare zirconium chalcogenide films and zirconium chalcogenide films capped with a metal silicate capping layer according to an embodiment of the present disclosure.

[0018] [Figure 7] FIG. 7A is grazing incidence x-ray diffraction (GIXRD) data of exemplary zirconium chalcogenide films without a capping layer deposited using different numbers of deposition cycles deposited on the chalcogenide film in accordance with an embodiment of the present disclosure.

[0019] FIG. 7B is grazing incidence x-ray diffraction (GIXRD) data of exemplary zirconium chalcogenide films having capping layers deposited using different numbers of deposition cycles deposited on the chalcogenide film in accordance with an embodiment of the present disclosure.

[0020] [Figure 8] FIG. 8 is an exemplary semiconductor device structure including a deposited transition metal chalcogenide film according to an embodiment of the present disclosure.

[0021] [Figure 9] FIG. 9 is an exemplary reaction system that can be utilized to deposit transition metal chalcogenide films according to embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Although several embodiments and examples are disclosed below, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments and / or applications of the present 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 described below.

[0023] The figures presented herein are not meant to be actual illustrations of any particular materials, structures or devices, but merely idealized representations used to explain embodiments of the present disclosure.

[0024] As used herein, the term "substrate" may refer to any underlying material or materials that may be used or upon which a device, circuit or film may be formed.

[0025] As used herein, the term "cyclic deposition" refers to the sequential introduction of precursors (reactants) into a reaction chamber to deposit a film on a substrate, and includes deposition techniques such as atomic layer deposition and cyclic chemical vapor deposition.

[0026] The term "atomic layer deposition" (ALD) as used herein can refer to a vapor deposition process in which a deposition cycle, preferably multiple consecutive deposition cycles, are performed in a process chamber. Typically, during each cycle, a precursor chemisorbs to the deposition surface (e.g., the surface of a substrate or a surface of a previously deposited underlayer, such as a material deposited using a previous ALD cycle) and forms a monolayer or submonolayer that does not readily react with additional precursors (i.e., a self-limiting reaction). If necessary, a reactant (e.g., another precursor or a reactant gas) can 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 after conversion of the chemisorbed precursor and / or to remove excess reactants and / or reaction by-products from the process chamber. Additionally, the term "atomic layer deposition" as used herein is also meant to include processes denoted by related terms, such as, for example, chemical vapor deposition atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, or metalorganic MBE, as well as chemical beam epitaxy when performed with alternating pulses of precursor compositions, reactive gases, and purge (e.g., inert carrier) gases.

[0027] As used herein, the term "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.

[0028] As used herein, the term "chalcogen-containing gas-phase reactant" can refer to a reactant (precursor) that contains chalcogen, where chalcogen is an element in Group VI of the periodic table, which includes sulfur, selenium, and tellurium.

[0029] As used herein, the terms "film" and "thin film" are intended to mean any continuous or non-continuous structures and materials deposited by the methods disclosed herein. "Films" and "thin films" can include, for example, 2D materials, nanolaminates, nanorods, nanotubes, or nanoparticles, or partial or complete molecular layers, or partial or complete atomic layers, or clusters of atoms and / or molecules. "Films" and "thin films" can include materials or layers that have pinholes, but are still at least partially continuous.

[0030] As used herein, the term "2D material" or "two-dimensional material" can refer to nanometer-scale crystalline materials with thicknesses of one, two, or three atoms. Additionally, "2D material" or "two-dimensional material" can also refer to ordered nanometer-scale crystalline structures composed of multiple monolayers of crystalline material with thicknesses of approximately three atoms per monolayer.

[0031] As used herein, the term "halide precursor" can refer to a transition metal halide precursor that includes a halide component that includes at least one of chlorine, iodine, or bromine.

[0032] As used herein, the term "organometallic precursor" refers to a transition metal organometallic precursor, and "metal organic" or "organometallic" can be used interchangeably to refer to an organic compound that contains a metal species. Organometallic compounds are considered to be a subclass of organometallic compounds that have a direct metal-carbon bond.

[0033] It should be noted that many example materials are provided throughout the embodiments of this disclosure, and the chemical formulas provided for each of the example materials should not be construed as limiting, nor should the non-limiting example materials provided be limited by certain example stoichiometries.

[0034] The embodiments of the present disclosure may include a method for depositing a transition metal chalcogenide on a substrate by a cyclic deposition process, specifically a method for depositing a transition metal chalcogenide film containing either a hafnium component or a zirconium component by an atomic layer deposition process. As a non-limiting example, hafnium disulfide (HfS2) and zirconium disulfide (ZrS2) are new materials with 2D crystal structures similar to well-known transition metal dichalcogenides (TMDCs), such as molybdenum disulfide (MoS2). Compared to most studied 2D materials, graphene, hafnium disulfide, and zirconium disulfide may have significantly larger band gaps, making such exemplary transition metal chalcogenide films more suitable for semiconductor device structures, such as field effect transistors (FETs).

[0035] Current methods for forming transition metal chalcogenide films are not suitable for forming high quality, conformal, low temperature thin films. Transition metal chalcogenide crystals may be formed by mechanical exfoliation of bulk transition metal chalcogenide crystals, but such methods are not suitable for forming transition metal chalcogenide films with atomic scale thickness precision on suitable substrates. Furthermore, while chemical vapor deposition of some transition metal chalcogenide films has been demonstrated, such processes operate at high deposition temperatures (e.g., over 900°C for HfS2) and are unsuitable for producing nanoscale conformal thin films.

[0036] Cyclic deposition methods, such as cyclic chemical vapor deposition and atomic layer deposition, are inherently scalable and provide atomically precise film thickness control that is essential for the deposition of high quality 2D materials. Furthermore, cyclic deposition methods that involve surface control in the reaction, such as atomic layer deposition, are characteristically conformal, thereby offering the ability to uniformly coat three-dimensional structures.

[0037] Additionally, transition metal chalcogenide films can be susceptible to oxidation, either during the deposition process or when exposed to environmental conditions. Thus, cyclic deposition methods that do not incorporate transition metal oxide phases into the chalcogenide film during deposition may be desirable. Additionally, methods of preventing oxidation of transition metal chalcogenide films when exposed to environmental conditions are highly desirable.

[0038] Therefore, methods are desired that can deposit transition metal chalcogenide films conformally at reduced temperatures and with atomic thickness precision. Additionally, semiconductor device structures comprising transition metal chalcogenide films are desirable.

[0039] Non-limiting exemplary embodiments of cyclic deposition processes include ALD, which is based on a typical self-limiting reaction whereby sequential and alternating pulses of reactants are used to deposit approximately one atomic (or molecular) monolayer of material per deposition cycle. Deposition conditions and precursors are typically selected to provide a self-saturating reaction such that an adsorbed layer of one reactant leaves a surface termination unreactive with the gas-phase reactant of the same reactant. The substrate is then contacted with a different reactant that reacts with the previous termination, allowing for successive depositions. Thus, each cycle of alternating pulsed reactants typically leaves only approximately one monolayer of the desired material. However, as noted above, one skilled in the art will recognize that more than one monolayer of material can be deposited in one or more ALD cycles, for example, if several gas-phase reactions occur despite the alternating nature of the process.

[0040] In an ALD-type process for depositing a transition metal chalcogenide film, one deposition cycle can include exposing a substrate to a first gas-phase reactant, removing any unreacted first reactant and reaction by-products from the reaction space, and exposing the substrate to a second gas-phase reactant, followed by a second removing step. The first reactant can include a transition metal-containing precursor, such as a hafnium precursor or a zirconium precursor, and the second reactant can include a chalcogen-containing precursor.

[0041] The precursors can be separated by an inert gas, e.g., argon (Ar) or nitrogen (N2), to prevent gas-phase reactions between the reactants and to allow self-saturating surface reactions. However, in some embodiments, the substrate can be moved to contact the first and second gas-phase reactants separately. Since the reaction is self-saturating, strict temperature control of the substrate and precise injection rate control of the precursors may not be necessary. However, the substrate temperature is preferably such that the incident gas species do not condense into a monolayer and do not decompose on the substrate surface. Before contacting the substrate with the next reactive chemical, excess chemicals and reaction by-products, if any, are removed from the substrate surface, e.g., by purging the reaction space or by moving the substrate. Undesired gas molecules can be effectively evacuated from the reaction space using an inert purge gas. A vacuum pump can be used to facilitate the purge process.

[0042] Any reactor that can be used to deposit or grow a thin film can be used for deposition. Such reactors include ALD reactors equipped with appropriate devices and means for delivering precursors, as well as CVD reactors. According to some embodiments, a showerhead reactor can be used. In some embodiments, the reactor is a spatial ALD reactor in which the substrate moves or rotates during processing.

[0043] In some embodiments, a batch reactor may be used. In some embodiments, a vertical batch reactor is utilized in which the boat rotates within the reactor during processing. Thus, in some embodiments, the wafers rotate during processing. In other embodiments, the batch reactor comprises a mini-batch reactor configured to accommodate 10 or less wafers, 8 or less wafers, 6 or less wafers, 4 or less wafers, or 2 wafers. In some embodiments where a batch reactor is used, the wafer-to-wafer non-uniformity is less than 3% (1 sigma), less than 2%, less than 1% or even less than 0.5%.

[0044] The deposition methods described herein can optionally be performed in a reactor or reaction chamber that is coupled to a cluster tool. In a cluster tool, the temperature of the reaction chambers in each module can be kept constant because each reaction chamber is dedicated to one type of process, improving throughput compared to reactors that heat the substrate to a process temperature before each run. Additionally, a cluster tool allows for reduced time to evacuate the reaction space to the desired process pressure level between substrates.

[0045] A stand-alone reactor is equipped with a load lock, in which case there is no need to cool the reaction chamber between runs. In some embodiments, a deposition process for depositing a film, including a transition metal chalcogenide film, can include multiple deposition cycles, such as ALD cycles.

[0046] In some embodiments, a cyclic deposition process is used to deposit a transition metal chalcogenide film on a substrate, and the cyclic deposition process may be an ALD type process. In some embodiments, the cyclic deposition can be a hybrid ALD / CVD or cyclic CVD process. For example, in some embodiments, the deposition rate of an ALD process may be low compared to a CVD process. One approach 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 still utilizing sequential introduction of precursors, such a process may be referred to as cyclic CVD. In some embodiments, the cyclic CVD process may include the introduction of two or more precursors into a reaction chamber, with periods 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 cyclic CVD process may include a continuous flow of a first precursor and periodic pulse injection of a second precursor into the reaction chamber.

[0047] According to some embodiments of the present disclosure, an ALD process is used to deposit a transition metal chalcogenide film on a substrate, such as an integrated circuit workpiece. In some embodiments, each ALD cycle may include two distinct deposition steps or phases. In a first phase of the deposition cycle ("metal phase"), the substrate surface on which deposition is desired is contacted with a first gas-phase reactant including at least one of a hafnium precursor or a zirconium precursor that includes a metal precursor that chemisorbs onto the substrate surface and forms no more than about one monolayer of reactant species on the substrate surface. In a second phase of the deposition cycle ("chalcogen phase"), the substrate surface on which deposition is desired is contacted with a second gas-phase reactant including at least one chalcogen-containing gas-phase reactant that reacts with the previously chemisorbed species to form a transition metal chalcogenide film.

[0048] In some embodiments of the present disclosure, the transition metal-containing gas-phase reactant comprises at least one of a hafnium precursor or a zirconium precursor. In some embodiments, the hafnium precursor or zirconium precursor comprises at least one of a halide precursor or an organometallic precursor. In some embodiments, the metal organic precursor may comprise at least one of an alkylamide precursor or a cyclopentadienyl ligand-containing precursor. In some embodiments, the hafnium precursor or zirconium precursor may comprise a heteroleptic precursor.

[0049] In some embodiments, the hafnium precursor may include at least one of a hafnium halide precursor, a hafnium organometallic precursor, or an organometallic hafnium precursor.

[0050] As described later herein, in some embodiments, the hafnium halide precursor may include at least one halogen ligand, while the remaining ligands, e.g., metallo-organic or organometallic ligands, are different, hi some embodiments, the hafnium halide precursor may include one, two, three, or four halide ligands, e.g., chloride ligands.

[0051] In some embodiments, the hafnium halide precursor may include at least one of hafnium chloride, hafnium iodide, or hafnium bromide. In some embodiments, the hafnium chloride may include hafnium tetrachloride (HfCl4). In some embodiments, the hafnium iodide may include hafnium tetraiodide (HfI4). In some embodiments, the hafnium bromide may include hafnium tetrabromide (HfBr4).

[0052] In some embodiments, the hafnium organometallic precursor can include at least one of a hafnium alkylamide precursor, a hafnium cyclopentadienyl ligand-containing precursor, or other organometallic hafnium precursor.

[0053] In some embodiments, the hafnium alkylamide precursor can be selected from the group including tetrakis(ethylmethylamido)hafnium (Hf(NEtMe)4), tetrakis(dimethylamido)hafnium (Hf(NMe2)4), or tetrakis(diethylamido)hafnium (Hf(NEt2)4).

[0054] In some embodiments of the present disclosure, the hafnium cyclopentadienyl ligand-containing precursor may be selected from the group including (tris(alkylamido)cyclopentadienylhafnium, such as (tris(dimethylamido)cyclopentadienylhafnium HfCp(NMe2)3, or bis(methylcyclopentadienyl)methoxymethylhafnium (MeCp)2Hf(CH)3(OCH3), or derivatives thereof, such as those having one or more hydrocarbon, such as alkyl groups, bonded to the cyclopentadienyl ligands of these precursors, or other alkyl groups of the alkylamido ligands.

[0055] In some embodiments, the hafnium precursor has the formula: HfL1L2L3L4 (In the formula, each L ligand from L1 to L4 is a) Halides, such as chloride, bromide, or iodide b) Alkylamides, such as dimethylamide (-NMe2), diethylamide (-NEt2), ethylmethylamide (-NEtMe) c) amidinates, such as N,N'-dimethylformamidinate d) Guanidinates, such as N,N'-diisopropyl-2-ethylmethylamidoguanidinate. e) cyclopentadienyl or derivatives thereof, such as cyclopentadienyl or methylcyclopentadienyl or other alkyl-substituted cyclopentadienyl ligands. f) cycloheptadienyl or cycloheptatrienyl systems, e.g. cycloheptatrienyl or cycloheptadienyl g) Alkyl, e.g., C1-C5 alkyl, e.g., mostly methyl in the case of heteroleptic precursors h) Alkoxides, such as methoxide (-OMe), ethoxide (-OEt), isopropoxide (-O i Pr), n-butoxide (-OBu) or tert-butoxide (-O t Bu) i) Beta-diketonates, such as (2,2,6,6-tetramethyl-3,5-heptanedionate) (THD) j) independently selected to be a donor-functionalized alkoxide, e.g., dimethylethanolamine.

[0056] In some embodiments of the present disclosure, the hafnium precursor comprises one or more bidentate ligands bonded to Hf through nitrogen and / or oxygen atoms, hi some embodiments, the hafnium precursor comprises one or more ligands bonded to Hf through nitrogen, oxygen, and / or carbon.

[0057] In some embodiments, the zirconium precursor may include at least one of a zirconium halide precursor, a zirconium organometallic precursor, or an organometallic zirconium precursor.

[0058] In some embodiments, the zirconium halide precursor may include at least one of zirconium chloride, zirconium iodide, or zirconium bromide. In some embodiments, the zirconium chloride may include zirconium tetrachloride (ZrCl4). As described herein below, in some embodiments, the zirconium halide precursor may include at least one halogen ligand, and the remaining ligands, e.g., metallo-organic or organometallic ligands, are different. In some embodiments, the zirconium halide precursor may include one, two, three, or four halide ligands, e.g., chloride ligands. In some embodiments, the zirconium iodide may include zirconium tetraiodide (ZrI4). In some embodiments, the zirconium bromide may include zirconium tetrabromide (ZrBr4).

[0059] In some embodiments, the zirconium organometallic precursor can include at least one of a zirconium alkylamide precursor, a zirconium cyclopentadienyl ligand-containing precursor, or other organometallic zirconium precursor.

[0060] In some embodiments, the zirconium alkylamide precursor can be selected from the group including tetrakis(ethylmethylamido)zirconium (Zr(NEtMe)4), tetrakis(dimethylamido)zirconium (Zr(NMe2)4), or tetrakis(diethylamido)zirconium (Zr(NEt2)4).

[0061] In some embodiments of the present disclosure, the zirconium cyclopentadienyl ligand-containing precursor may be selected from the group including (tris(alkylamido)cyclopentadienyl zirconium, such as (tris(dimethylamido)cyclopentadienyl zirconium ZrCp(NMe2)3, or bis(methylcyclopentadienyl)methoxymethylzirconium (MeCp)2Zr(CH)3(OCH3), or derivatives thereof, such as those having one or more hydrocarbon, such as alkyl groups, attached to the cyclopentadienyl ligands of these precursors, or other alkyl groups of the alkylamido ligands.

[0062] In some embodiments, the zirconium precursor has the formula: ZrL1L2L3L4 (In the formula, each L ligand from L1 to L4 is k) Halides, such as chloride, bromide, or iodide l) Alkylamides, such as dimethylamide (-NMe2), diethylamide (-NEt2), ethylmethylamide (-NEtMe) m) amidinates, such as N,N'-dimethylformamidinate n) guanidinates, such as N,N'-diisopropyl-2-ethylmethylamidoguanidinate o) cyclopentadienyl or derivatives thereof, such as cyclopentadienyl or methylcyclopentadienyl or other alkyl-substituted cyclopentadienyl ligands. p) cycloheptadienyl or cycloheptatrienyl systems, for example cycloheptatrienyl or cycloheptadienyl q) Alkyl, e.g., C1-C5 alkyl, e.g., mostly methyl in the case of heteroleptic precursors r) Alkoxides, such as methoxide (-OMe), ethoxide (-OEt), isopropoxide (-O i Pr), n-butoxide (-OBu) or tert-butoxide (-O t Bu) s) Beta-diketonates, such as (2,2,6,6-tetramethyl-3,5-heptanedionate) (THD) t) independently selected to be a donor functionalized alkoxide, such as dimethylethanolamine.

[0063] In some embodiments of the present disclosure, the zirconium precursor comprises one or more bidentate ligands bonded to Zr through nitrogen and / or oxygen atoms, hi some embodiments, the zirconium precursor comprises one or more ligands bonded to Zr through nitrogen, oxygen, and / or carbon.

[0064] In some embodiments, exposing the substrate to the transition metal-containing gas phase reactant can include pulsing the transition metal precursor onto the substrate for about 0.01 seconds to about 60 seconds, about 0.05 seconds to about 10 seconds, or about 0.1 seconds to about 5.0 seconds. In addition, during pulsing the transition metal precursor onto the substrate, the flow rate of the transition metal precursor can be less than 2000 sccm, or less than 500 sccm, or even less than 100 sccm. In addition, during pulsing the transition metal precursor onto the substrate, the flow rate of the transition metal precursor can be about 1 to about 2000 sccm, about 5 to about 1000 sccm, or about 10 to about 500 sccm.

[0065] In some embodiments, the purity of the transition metal-containing gas phase reactant can affect the composition of the deposited film, and therefore high purity sources of the transition metal-containing gas phase reactant can be utilized. For example, in some embodiments, the transition metal gas phase reactant may include a hafnium precursor or a zirconium precursor having a purity of 99.99% or greater.

[0066] In some embodiments, the transition metal-containing gas phase reactant may be placed in a vessel, and one or more heaters may be associated with the vessel to control the temperature of the metal precursor and, subsequently, the partial pressure of the metal precursor. In some embodiments of the present disclosure, the metal precursor in the vessel may be heated to a temperature of about 20° C. to about 300° C. For example, in some embodiments, the metal 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 choice of precursor.

[0067] In some embodiments, the vessel containing the metal precursor may be connected to one or more sources of carrier gas. The carrier gas may be introduced into the vessel and drawn over the surface of the metal precursor contained within the vessel or blown through the metal precursor. The resulting evaporation of the metal precursor results in the vapor of the metal precursor being entrained in the carrier gas, thereby generating a transition metal vapor phase reactant that can be injected into the reaction chamber.

[0068] In some embodiments, in addition to utilizing high purity transition metal precursors, the carrier gas can be further purified to remove unwanted impurities. Thus, some embodiments of the present disclosure may further include flowing the carrier gas through a vessel containing a source of transition metal-containing gas phase reactant to transport the transition metal-containing gas phase reactant to the reaction chamber. Further embodiments of the present disclosure may include flowing the carrier through a gas purifier prior to entering the source of transition metal-containing gas phase reactant to reduce the concentration of at least one of water or oxygen in the carrier gas.

[0069] 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.

[0070] 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.

[0071] In some embodiments, the hydrogen (H2) concentration in the carrier gas can be reduced to less than 100 ppt. In some embodiments, the carbon dioxide (CO2) 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.

[0072] In some embodiments, the carrier gas may include nitrogen gas (N2), and the carrier gas purifier may comprise a nitrogen gas purifier.

[0073] In some embodiments of the present disclosure, the transition metal-containing gas-phase reactant may be fed through a gas purifier prior to entering the reaction chamber to reduce the concentration of at least one of water or oxygen in the transition metal-containing gas-phase reactant.

[0074] In some embodiments, the moisture concentration in the transition metal-containing gas phase reactant 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.

[0075] In some embodiments, the oxygen concentration in the transition metal-containing gas phase reactant 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] Without being bound by any theory or mechanism, it is believed that a reduction in at least one of the water concentration or oxygen concentration in the carrier gas and / or the transition metal-containing gas phase reactant allows for the deposition of transition metal chalcogenide films of desired composition while preventing the deposition of transition metal oxide phases at suitable deposition temperatures.

[0077] Excess transition metal vapor phase reactant, e.g., hafnium precursor or zirconium precursor, and reaction by-products, if any, can be removed from the substrate surface, e.g., by pumping with an inert gas. For example, in some embodiments of the present disclosure, the method can include a purge cycle, where the substrate surface is purged for a time period less than about 5.0 seconds, or less than about 2.0 seconds, or even less than about 1.0 seconds. In some embodiments, the substrate surface is purged for a time period between about 0.01 seconds and about 60 seconds, or between about 0.05 seconds and about 10 seconds, or between about 0.1 seconds and about 5 seconds. Excess transition metal vapor phase reactant and any reaction by-products can be removed using a vacuum generated by a pumping device.

[0078] In a second stage of the deposition cycle (the "chalcogen phase"), the substrate is contacted with a second gas phase reactant comprising at least one chalcogen-containing gas phase reactant. In some embodiments of the present disclosure, the at least one chalcogenide-containing gas phase reactant may comprise hydrogen sulfide (H2S), hydrogen selenide (H2Se), dimethyl sulfide ((CH3)2S), or dimethyl telluride ((CH3)2Te).

[0079] It will be appreciated by those skilled in the art that many chalcogen precursors can be used in the cyclic deposition process disclosed herein. In some embodiments, the chalcogen precursor is selected from the following list: H2S, H2Se, H2Te, (CH3)2S, (NH4)2S, dimethylsulfoxide ((CH3)2SO), (CH3)2Se, (CH3)2Te, elemental or atomic S, Se, Te, other precursors containing chalcogen-hydrogen bonds, such as H2S2, H2Se2, H2Te2, or chalcogenols having the formula RYH, where R is 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 precursor is a thiol having the formula RSH, where R can be a substituted or unsubstituted hydrocarbon, preferably a C1-C8 alkyl group, more preferably a linear or branched C1-C5 alkyl group. In some embodiments, the chalcogen precursor has the formula (R3Si)2Y, where R3Si is an alkylsilyl group and Y can be S, Se, or Te. In some embodiments, the chalcogen precursor comprises S or Se. In some embodiments, the chalcogen precursor comprises S. In some embodiments, the chalcogen precursor does not comprise S. In some embodiments, the chalcogen precursor may comprise a chalcogen element, for example, elemental sulfur. In some embodiments, the chalcogen precursor comprises Te. In some embodiments, the chalcogen precursor does not comprise Te. In some embodiments, the chalcogen precursor comprises Se. In some embodiments, the chalcogen precursor does not comprise Se. In some embodiments, the chalcogen precursor is selected from precursors comprising S, Se, or Te. In some embodiments, the chalcogen precursor comprises H2S n (wherein n is 4 to 10).

[0080] In some embodiments, suitable chalcogen precursors may include many chalcogen-containing compounds. In some embodiments, the chalcogen precursor may include at least one chalcogen-hydrogen bond. In some embodiments, the chalcogen precursor may include a chalcogen plasma, a chalcogen atom, or a chalcogen radical. In some embodiments where an excited chalcogen precursor is desired, a plasma may be generated in the reaction chamber or upstream of the reaction chamber. In some embodiments, the chalcogen precursor does not include an excited chalcogen precursor, such as a plasma, an atom, or a radical. In some embodiments, the chalcogen precursor may include a chalcogen plasma, a chalcogen atom, or a chalcogen radical formed from a chalcogen precursor that includes a chalcogen-hydrogen bond, such as H2S. In some embodiments, the chalcogen precursor may include a chalcogen plasma, a chalcogen atom, or a chalcogen radical, such as a plasma that includes sulfur, selenium, or tellurium, preferably a plasma that includes sulfur. In some embodiments, the plasma, atom, or radical includes tellurium. In some embodiments, the plasma, atom, or radical includes selenium. In some embodiments, the chalcogen precursor does not include a tellurium precursor.

[0081] In some embodiments, the purity of the chalcogen-containing gas phase reactant can affect the composition of the deposited film, and therefore a high purity source of the chalcogen-containing gas phase reactant can be utilized. In some embodiments, the chalcogen-containing gas phase reactant can have a purity of 99.5% or greater. As a non-limiting example, the chalcogen-containing gas phase reactant may include hydrogen sulfide (H2S) of 99.5% or greater purity.

[0082] In some embodiments, in addition to utilizing a high purity chalcogen-containing gas-phase reactant, the chalcogen precursor gas can be further purified to remove unwanted impurities. Thus, some embodiments of the present disclosure may further include flowing the chalcogen-containing gas-phase reactant through a gas purifier prior to entering the reaction chamber to reduce the concentration of at least one of water or oxygen in the chalcogen-containing gas-phase reactant.

[0083] In some embodiments, the water or oxygen concentration in the chalcogen-containing gas phase 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.

[0084] Without being bound by any theory or mechanism, it is believed that a reduction in at least one of the water concentration or oxygen concentration in the chalcogen-containing gas phase reactant allows for the deposition of a transition metal chalcogenide film of a desired composition while preventing the deposition of transition metal oxide phases at suitable deposition temperatures.

[0085] In some embodiments, exposing the substrate to the chalcogen-containing gas phase reactant may include pulsing a chalcogen precursor (e.g., hydrogen sulfide) onto the substrate for a time period between 0.1 seconds and 2.0 seconds, or between about 0.01 seconds and about 10 seconds, or less than about 20 seconds, or less than about 10 seconds, or less than about 5 seconds. During pulsing of the chalcogen precursor onto the substrate, the flow rate of the chalcogen precursor may be less than 2000 sccm, or less than 500 sccm, or even less than 100 sccm. Additionally, during pulsing of the chalcogen precursor onto the substrate, the flow rate of the chalcogen precursor may be between about 1 sccm and about 2000 sccm, or between about 5 sccm and about 1000 sccm, or between about 10 sccm and about 500 sccm.

[0086] A second vapor phase reactant comprising a chalcogen-containing precursor can react with the metal-containing molecules remaining on the substrate, in some embodiments, the second phase chalcogen precursor can comprise hydrogen sulfide, and the reaction can deposit a transition metal disulfide on the surface of the substrate.

[0087] For example, excess second source chemical and reaction by-products, if any, may be removed from the surface of the substrate by pulses of purge gas and / or vacuum created by an evacuation system. The purge gas is preferably any inert gas, such as, but not limited to, argon (Ar), nitrogen (N2), or helium (He). One stage is generally considered to follow immediately after another stage if a purge (i.e., purge gas pulse) or other reactant removal step is intervening.

[0088] The deposition cycle of alternately contacting the substrate with a first gas-phase reactant (i.e., a transition metal-containing precursor) and a second gas-phase reactant (i.e., a chalcogen-containing precursor) may be repeated one or more times until a desired thickness of the transition metal chalcogenide is deposited. Of course, in some embodiments of the present disclosure, the order of contacting the substrate with the first and second gas-phase reactants may be such that the substrate is first contacted with the second gas-phase reactant followed by contact with the first gas-phase reactant. Furthermore, in some embodiments, the cyclic deposition process may include contacting the substrate with the first gas-phase reactant (i.e., a transition metal-containing precursor) one or more times before contacting the substrate with the second gas-phase reactant (i.e., a chalcogen-containing precursor) one or more times, or similarly, contacting the substrate with the second gas-phase reactant one or more times before contacting the substrate with the first gas-phase reactant one or more times.

[0089] Additionally, some embodiments of the present disclosure may be free of plasma reactants, e.g., the first and second gas phase reactants are substantially free of ionized reactants. In some embodiments, the first and second gas phase reactants are substantially free of ionized reactants, excited species, and radical species. For example, both the first and second gas phase reactants may be free of plasma reactants to prevent ionization damage of the underlying substrate and associated defects generated thereby.

[0090] The cyclic deposition processes described herein utilizing transition metal-containing and chalcogen-containing precursors to form transition metal chalcogenide films can be carried out in an ALD or CVD deposition system with a heated substrate, i.e., the temperature of the substrate during the process of contacting the substrate with the chemical precursors can be controlled.

[0091] For example, in some embodiments, the method may include heating the substrate to a temperature of about 200° 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, such as an ALD reaction, will depend on the surface termination and reactant species involved, where the temperature varies 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 more. 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 than about 300° C. In some embodiments, for example, when additional reactants or reducing agents are 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 embodiments, the deposition temperature may be greater than about 20° C., greater than about 50° C., and greater than about 75° C. In some embodiments of the present disclosure, the deposition temperature, i.e., the temperature of the substrate during deposition, is about 400° C.

[0092] In some embodiments, the growth rate of the transition metal chalcogenide film is about 0.005 Å / cycle to about 5 Å / cycle, or about 0.01 Å / cycle to about 2.0 Å / cycle. In some embodiments, the growth rate of the film 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 growth rate of the film 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. In some embodiments of the present disclosure, the growth rate of the transition metal chalcogenide is about 0.10 Å / cycle.

[0093] Embodiments of the present disclosure can include a cyclic deposition process, which can be illustrated in more detail by the exemplary method 100 of Figure 1. The exemplary method 100 can begin by process block 110, which includes providing a substrate into a reaction chamber and heating the substrate to a deposition temperature.

[0094] In some embodiments of the present disclosure, the substrate may include a planar substrate or a patterned substrate including high aspect ratio features, such as trench structures and / or fin structures. The substrate may 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 III-V semiconductor materials, such as gallium arsenide (GaAs), gallium phosphide (GaP), or gallium nitride (GaN). In some embodiments, the substrate may include one or more dielectric materials including, but not limited to, oxides, nitrides, or oxynitrides. For example, the substrate may 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 may comprise an engineered substrate, where a surface semiconductor layer is disposed on a bulk support with an intervening buried oxide (BOX) disposed therebetween.

[0095] The patterned substrate may comprise a substrate that may include semiconductor device structures formed in or on a surface of the substrate, for example, the patterned substrate may include partially fabricated semiconductor device structures, such as transistors and / or memory elements. In some embodiments, the substrate may include one or more secondary surfaces that may include single crystal surfaces and / or non-single crystal surfaces, such as polycrystalline surfaces and / or amorphous surfaces. The single crystal surfaces may include, for example, one or more of silicon (Si), silicon germanium (SiGe), germanium tin (GeSn), germanium (Ge), or III-V materials. The polycrystalline or amorphous surfaces may include dielectric materials, such as oxides, oxynitrides, or nitrides, such as silicon oxides and silicon nitrides.

[0096] The reaction chamber utilized in the exemplary cyclical deposition process 100 may be an atomic layer deposition reaction chamber, or a chemical vapor deposition reaction chamber, or any of the reaction chambers previously described herein. In some embodiments of the present disclosure, the reaction chamber may undergo a pre-annealing process prior to introducing the substrate into the reaction chamber, or with the substrate pre-introduced into the reaction chamber. For example, the pre-annealing process may be utilized to reduce the concentration of at least one of water and / or oxygen in the reaction chamber. Thus, some embodiments of the present disclosure may further include pre-annealing the reaction chamber at a temperature of greater than 400° C., or greater than 500° C., or greater than 600° C., or even greater than 700° C. prior to film deposition. In some embodiments, pre-annealing the reaction chamber at high temperature may be performed for a time period of less than 60 minutes, or less than 30 minutes, or less than 15 minutes, or less than 10 minutes, or even less than 5 minutes.

[0097] As previously described herein, process block 110 (of FIG. 1) can continue by heating the substrate to a desired deposition temperature. By way of non-limiting example, the substrate may be heated to a deposition temperature of about 300° C. to about 450° C., or to a temperature of about 400° C.

[0098] The exemplary method 100 can continue with a cyclical deposition phase 140, which can begin with a process block 120 that includes contacting the substrate with a transition metal-containing gas-phase reactant, as previously described herein. As a non-limiting example, the substrate can be contacted with hafnium tetrachloride (HfCl4) or zirconium tetrachloride (ZrCl4) for about 1 second. Once the substrate is contacted with the transition metal-containing precursor, excess transition metal-containing precursor and any by-products can be removed from the reaction chamber by a purge / evacuation process.

[0099] The cyclical deposition phase 140 of the exemplary method 100 may continue with process block 130, which includes contacting the substrate with a chalcogen-containing gas-phase reactant, as previously described herein. As a non-limiting example, the substrate may be contacted with hydrogen sulfide (H2S) for about 1 second. Once the substrate has been contacted with the chalcogen-containing precursor, excess chalcogen-containing precursor and any by-products may be removed from the reaction chamber by a purge / evacuation process.

[0100] A process in which the substrate is alternately and sequentially contacted with at least one transition metal-containing gas-phase reactant and at least one chalcogen-containing gas-phase reactant can constitute one unit deposition cycle. For example, a unit deposition cycle can include contacting the substrate with the transition metal gas-phase reactant, purging the reaction chamber, contacting the substrate with the chalcogen-containing gas-phase reactant, and purging the reaction chamber again.

[0101] In some embodiments of the present disclosure, the method of depositing a transition metal chalcogenide may include repeating a unit deposition cycle one or more times. For example, the cyclical deposition phase 140 of the exemplary method 100 may be continued by a decision gate 150 that determines whether the cyclical deposition phase 140 of the exemplary method 100 continues or ends. The decision gate at process block 150 may be determined based on the thickness of the transition metal chalcogenide film being deposited. For example, if the thickness of the transition metal chalcogenide film is insufficient for a desired application, the cyclical deposition phase 140 of the exemplary method 100 may return to process block 120 and the process of contacting the substrate with a transition metal-containing gas phase reactant and contacting the substrate with a chalcogen-containing gas phase reactant may be repeated one or more times. Once the transition metal chalcogenide film has been deposited to a desired thickness, the exemplary method 100 may end via process block 160, and the transition metal chalcogenide film may undergo additional processing to form a device structure.

[0102] In some embodiments of the present disclosure, the deposition temperature of the transition metal chalcogenide film can affect the growth rate of the chalcogenide film, the crystallinity of the chalcogenide film, and the composition of the chalcogenide film. As a non-limiting example, FIG. 2 shows the growth rate, crystallinity, and composition of an exemplary hafnium disulfide film deposited at various deposition temperatures using hafnium tetrachloride (HfCl4) and hydrogen sulfide (H2S) as precursor chemicals. Examination of FIG. 2 shows that the deposition rate of the exemplary hafnium disulfide film decreases between deposition temperatures of about 200° C. and deposition temperatures of about 350° C., indicating that the crystalline structure of the hafnium disulfide film is amorphous, i.e., lacking the long-range order of the crystalline structure typically associated with crystalline materials. At deposition temperatures between about 350° C. and about 400° C., the growth rate of the exemplary hafnium disulfide film increases and the crystal structure of the hafnium disulfide film becomes crystalline, i.e., there is long-range order in the crystal structure of the chalcogenide film. Additionally, at deposition temperatures between about 350° C. and about 400° C., the exemplary hafnium disulfide film exhibits a composition of hafnium disulfide (HfS2). However, as the deposition temperature is further increased beyond a temperature of about 400° C., the growth rate of the exemplary film decreases again and the composition of the deposited film becomes a mixture of hafnium sulfide and hafnium oxide. The deposition of the hafnium oxide phase above a temperature of about 400° C. may be due to residual oxygen and / or water remaining in the reaction chamber utilized in the non-limiting examples above. In another non-limiting example, the concentration of residual oxygen and / or water in the reaction chamber can be further reduced, and hafnium disulfide (HfS2) films can be deposited without the deposition of hafnium oxide phases upon deposition at temperatures above about 400°C.

[0103] Thus, in some embodiments of the present disclosure, the transition metal chalcogenide film may include hafnium sulfide, specifically hafnium disulfide (HfS2). Furthermore, in some embodiments, the transition metal chalcogenide film may be crystalline having a composition including hafnium disulfide (HfS2) at a deposition temperature of about 350° C. to about 400° C., particularly at a deposition temperature of about 400° C. In some embodiments, the crystalline hafnium disulfide (HfS2) film may be deposited at a deposition temperature greater than 400° C.

[0104] As another non-limiting example, FIG. 3 shows the growth rate, crystallinity, and composition of an exemplary zirconium sulfide film deposited at various deposition temperatures using zirconium tetrachloride (ZrCl4) and hydrogen sulfide (H2S) as precursor chemicals. Examination of FIG. 3 shows that between deposition temperatures of about 200° C. and deposition temperatures of about 350° C., the deposition rate of the exemplary zirconium sulfide film increases and the crystal structure of the zirconium sulfide film is amorphous, i.e., lacks the long-range order of the crystal structure typically associated with crystalline materials. At deposition temperatures between about 350° C. and about 400° C., the growth rate of the exemplary zirconium sulfide film further increases and the crystal structure of the zirconium sulfide film becomes crystalline, i.e., there is long-range order of the crystal structure of a chalcogenide film. Additionally, at deposition temperatures between about 350° C. and about 400° C., the exemplary zirconium sulfide film exhibits a composition of zirconium disulfide (ZrS2). However, as the deposition temperature is further increased above a temperature of about 400° C., the growth rate of the exemplary film initially decreases and then increases again, and the composition of the deposited film is that of a mixture of zirconium sulfide and zirconium oxide. The deposition of a zirconium oxide phase above a temperature of about 400° C. may be due to residual oxygen and / or water remaining in the reaction chamber utilized in the above non-limiting example. In another non-limiting example, the concentration of residual oxygen and / or water in the reaction chamber can be further reduced, and a zirconium disulfide (ZrS2) film can be deposited without the deposition of a zirconium oxide phase by deposition above a temperature of about 400° C.

[0105] Thus, in some embodiments of the present disclosure, the transition metal chalcogenide film can include zirconium sulfide, specifically zirconium disulfide (ZrS2). Further, in some embodiments, the transition metal chalcogenide film can be crystalline having a composition including zirconium disulfide (ZrS2) at a deposition temperature between about 350° C. and about 400° C., specifically at a deposition temperature of about 400° C. In some embodiments, the crystalline zirconium disulfide (ZrS2) film can be deposited at a deposition temperature greater than 400° C.

[0106] As another non-limiting example of transition metal chalcogenide films deposited according to embodiments of the present disclosure, FIGS. 4 and 5 illustrate grazing incidence x-ray diffraction (GIXRD) data for a hafnium sulfide film deposited using hafnium tetrachloride (HfCl4) and hydrogen sulfide (HS) as chemical precursors (FIG. 4) and a zirconium sulfide film deposited utilizing zirconium tetrachloride (ZrCl4) and hydrogen sulfide (HS) as chemical precursors (FIG. 5) deposited at various deposition temperatures from 200° C. to 500° C.

[0107] Examination of FIG. 4 indicates that from a deposition temperature of 200° C. to a deposition temperature of 350° C., the GIXRD data does not include any identifiable peaks in the data, corresponding to a non-crystalline film, i.e., the exemplary hafnium sulfide film is amorphous. From a deposition temperature of 400° C. to a deposition temperature of 450° C., the GIXRD data has an identifiable main peak corresponding to a crystalline hafnium sulfide film, specifically a hafnium disulfide film having the composition (HfS2). Additionally, at deposition temperatures between 400° C. and 450° C., the exemplary hafnium disulfide film has a (001) preferred crystal orientation, as indicated by the location of the peaks in the GIXRD data. For a deposition temperature of 500° C., no peaks in the GIXRD data related to hafnium disulfide are identifiable, however, several minor peaks corresponding to hafnium oxide (e.g., HfO2) are present, indicating that the deposited film includes a hafnium oxide film. As previously discussed herein, the presence of hafnium oxide phases in 500° C. depositions may be due to residual water and / or oxygen in the reaction chamber utilized to deposit the exemplary hafnium sulfide film of Figure 4. In another non-limiting example, a reaction chamber utilized to deposit a hafnium sulfide film may have reduced concentrations of water and / or oxygen, and deposition at temperatures of 500° C. or greater may result in a crystalline hafnium sulfide film that is free of hafnium oxide phases.

[0108] Thus, in some embodiments of the present disclosure, the transition metal chalcogenide film can include hafnium sulfide, specifically hafnium disulfide (HfS2). Further, in some embodiments, the transition metal chalcogenide film can include crystalline hafnium disulfide (HfS2) having a (001) preferred crystal orientation at a deposition temperature between about 350° C. and about 400° C., specifically at a deposition temperature of about 400° C. In some embodiments, the transition metal chalcogenide film can include crystalline hafnium disulfide (HfS2) having a (001) preferred crystal orientation for deposition temperatures greater than 400° C.

[0109] Additionally, GIXRD data from the exemplary zirconium sulfide film is shown in FIG. 5, and examination of FIG. 5 indicates that from a deposition temperature of 200° C. to a deposition temperature of 300° C., the GIXRD data does not include any identifiable peaks in the data, corresponding to a non-crystalline film, i.e., the exemplary zirconium sulfide film is amorphous. From a deposition temperature of 350° C. to a deposition temperature of 450° C., the GIXRD data has a single identifiable peak corresponding to a crystalline zirconium sulfide film, specifically a zirconium disulfide film having the composition (ZrS2). Additionally, at deposition temperatures between 350° C. and 450° C., the exemplary zirconium disulfide film has a (001) preferred crystal orientation, as indicated by the location of the peak in the GIXRD data. For a deposition temperature of 500° C., there are peaks in the GIXRD data associated with zirconium disulfide, but there are also several minor peaks corresponding to zirconium oxide (e.g., ZrO2), indicating that the deposited film includes a mixture of both zirconium sulfide and zirconium oxide. As previously discussed herein, the presence of zirconium oxide phases at a deposition temperature of 500° C. may be due to residual water and / or oxygen in the reaction chamber utilized to deposit the exemplary zirconium sulfide film of Figure 5. In another non-limiting example, the reaction chamber utilized to deposit the zirconium sulfide film may have reduced concentrations of water and / or oxygen, and deposition at temperatures of 500° C. or greater may result in a zirconia sulfide film that is free of zirconium oxide phases.

[0110] Thus, in some embodiments of the present disclosure, the transition metal chalcogenide film can include zirconium sulfide, specifically zirconium disulfide (ZrS2). Further, in some embodiments, the transition metal chalcogenide film can include crystalline zirconium disulfide (ZrS2) having a (001) crystal orientation at a deposition temperature between about 300° C. and about 450° C., specifically at a deposition temperature of about 400° C. In some embodiments, the transition metal chalcogenide film can include crystalline zirconium disulfide (ZrS2) having a (001) preferred crystal orientation at deposition temperatures above 400° C.

[0111] In some embodiments of the present disclosure, the as-deposited transition metal chalcogenide film may be subjected to a post-deposition annealing process to improve the crystallinity of the transition metal chalcogenide thin film. For example, in some embodiments, the method of depositing a transition metal chalcogenide film may further include a post-deposition annealing of the metal chalcogenide at a temperature higher than the deposition temperature of the transition metal chalcogenide film. For example, in some embodiments, the annealing of the transition metal chalcogenide may include heating the transition metal 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, the post-deposition annealing of the transition metal chalcogenide thin film may be performed in an atmosphere containing a chalcogen. For example, the post-deposition annealing process may be performed in an environment containing a chalcogenide compound, such as a sulfur compound, such as hydrogen sulfide (H2S) atmosphere. In some embodiments, the post-deposition anneal of the metal chalcogenide thin film can be performed for a time period of less than 1 hour, or less than 30 minutes, or less than 15 minutes, or even less than 5 minutes. In some embodiments, the post-deposition anneal of the transition metal chalcogenide thin film may be performed in an atmosphere that is free of chalcogens, such as S, Se, Te, for example in an inert gas environment, such as N2, or a noble gas, such as Ar or He, or in a hydrogen-containing environment, such as an H2 or H2 / N2 environment.

[0112] Transition metal chalcogenide films deposited according to some of the embodiments of the present disclosure, such as hafnium disulfide and zirconium disulfide films, may be continuous films including 2D materials. In some embodiments, films including transition metal chalcogenide films deposited according to some of the disclosures of the embodiments 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, or less.

[0113] In some embodiments, transition metal chalcogenide films deposited according to embodiments of the present disclosure can be continuous on substrates having diameters of greater than 100 millimeters, or greater than 200 millimeters, or greater than 300 millimeters, or even greater than 400 millimeters. Continuity as 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, and the thickness at which a film can be electrically continuous may not be the same as the thickness at which the film is physically continuous.

[0114] In some embodiments of the present disclosure, the transition metal chalcogenide films deposited by the methods disclosed herein may include at least one of hafnium sulfide, hafnium selenide, hafnium telluride, zirconium sulfide, zirconium selenide, or zirconium telluride.

[0115] In some embodiments of the present disclosure, the transition metal chalcogenide films deposited by the methods disclosed herein are hafnium chalcogenides, specifically those having the general formula HfS xwhere x may be in the range of about 0.75 to about 2.8, or x may be in the range of about 0.8 to about 2.5, or x may be in the range of 0.9 to about 2.3, or x may be in the range of about 0.95 to about 2.2. x The elemental composition range of Hf 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 % Hf. x % to about 75 atomic % S, or about 30 atomic % to about 60 atomic % S, or even about 35 atomic % to about 55 atomic % S.

[0116] In some embodiments of the present disclosure, the transition metal chalcogenide films deposited by the methods disclosed herein are zirconium chalcogenides, specifically those having the general formula ZrS x ZrS, where x is in the range of about 0.75 to about 2.8, or x is in the range of about 0.8 to about 2.5, or x is in the range of 0.9 to about 2.3, or x is in the range of about 0.95 to about 2.2. x The elemental composition range of ZrS 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 % Zr. x % to about 75 atomic % S, or about 30 atomic % to about 60 atomic % S, or even about 35 atomic % to about 55 atomic % S.

[0117] In further embodiments, the transition metal chalcogenide films of the present disclosure can include less than about 20 atomic % oxygen, or less than about 10 atomic % oxygen, or less than about 5 atomic % oxygen, or even less than about 2 atomic % oxygen. In another embodiment, the transition metal chalcogenide film can include less than about 25 atomic % hydrogen, or less than about 10 atomic % hydrogen, or less than about 5 atomic % hydrogen, or less than about 2 atomic % hydrogen, or even less than about 1 atomic % hydrogen. In yet another embodiment, the transition metal chalcogenide film can include less than about 20 atomic % carbon, or less than about 10 atomic % carbon, or less than about 5 atomic % carbon, or less than about 2 atomic % carbon, or less than about 1 atomic % carbon, or even less than about 0.5 atomic % 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).

[0118] In some embodiments of the present disclosure, the transition metal chalcogenide film may be deposited on a three-dimensional structure. In some embodiments, the step coverage of the transition metal chalcogenide film may be about 50% or more, or about 80% or more, or about 90% or more, or about 95%, or about 98%, or about 99% or more 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.

[0119] In some embodiments, the transition metal chalcogenide films of the present disclosure, such as hafnium and zirconium dichalcogenide films, may be deposited to a thickness of about 20 nanometers to about 100 nanometers. In some embodiments, the transition metal 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 transition metal 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, the transition metal 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.

[0120] In some embodiments, a transition metal chalcogenide film, such as a hafnium or zirconium dichalcogenide film deposited according to some of the embodiments described herein, can have a thickness of no more than about 10 monolayers of transition metal chalcogenide material, or no more than about 7 monolayers of transition metal chalcogenide material, or no more than about 5 monolayers of transition metal chalcogenide material, or no more than about 4 monolayers of transition metal chalcogenide material, or no more than about 3 monolayers of transition metal chalcogenide material, or no more than about 2 monolayers of transition metal chalcogenide material, or even no more than about 1 monolayer of transition metal chalcogenide material.

[0121] In some embodiments of the present disclosure, the transition metal chalcogenide films deposited according to the methods disclosed herein may include a protective capping layer that substantially prevents or even prevents undesired oxidation of the transition metal chalcogenide film. For example, once deposition of the transition metal chalcogenide is complete, the chalcogenide film may be removed from the reaction chamber and exposed to environmental conditions where oxygen and / or water in the surrounding environment may oxidize the deposited transition metal chalcogenide film.

[0122] Thus, in some embodiments, a capping layer may be deposited on the transition metal chalcogenide film, specifically, directly on the transition metal chalcogenide film. Furthermore, the capping layer may be deposited in the same reaction chamber utilized to deposit the transition metal chalcogenide, i.e., the capping layer may be deposited in-situ in the same reaction chamber utilized to deposit the transition metal chalcogenide film, to prevent any oxidation of the transition metal chalcogenide film. Thus, in some embodiments of the present disclosure, the method may further include depositing a capping layer in-situ on the transition metal chalcogenide film to substantially prevent oxidation of the transition metal chalcogenide film when exposed to environmental conditions.

[0123] In some embodiments, the capping layer may comprise a metal silicate film. In some embodiments, the metal silicate film is aluminum silicate (Al x S y O x ), hafnium silicate (Hf x S y O x ), or zirconium silicate (Zr x S y O x) More detailed information regarding 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 entire contents of which are incorporated herein by reference and made a part hereof.

[0124] As previously described herein, in some embodiments, the capping layer may be deposited directly on the transition metal chalcogenide film by a cyclic deposition process, such as an atomic layer deposition process or a cyclic chemical vapor deposition process. As a non-limiting example, the capping layer may include a metal silicate, which may be deposited by a cyclic deposition process, such as an atomic layer deposition process. In some embodiments, the capping layer may be deposited using a process that includes a non-oxidizing reactant / precursor or a process that includes a non-oxygen reactant (e.g., without O2, H2O, O3, H2O2, O-containing plasma, oxygen radicals, or oxygen atoms). Thus, in some embodiments, the capping layer may be deposited without the use of H2O, O3, or H2O2. In some embodiments, the capping layer may be deposited without the use of an oxygen-based plasma, i.e., without an O-containing plasma, oxygen radicals, oxygen atoms, and oxygen excited species. The capping layer may be deposited using a process that includes a non-oxidizing reactant / precursor, or a non-oxygen reactant, to prevent or substantially prevent oxidation of the underlying transition metal chalcogenide film. Thus, in some embodiments, in situ deposition of the capping layer on the transition metal chalcogenide film may be performed without additional oxidation of the transition metal chalcogenide film.

[0125] In other embodiments, the capping layer may comprise a metal, such as a transition metal. In some embodiments, the capping layer may 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 may be a dielectric layer. In other embodiments, the capping layer may be a conductive layer. In other embodiments, the capping layer may be a semiconductor layer.

[0126] 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 that includes both silicon and oxygen components, and purging the reaction chamber again. As a non-limiting example, the capping layer can be an aluminum silicate film (Al x S 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 include a metal silicate that is deposited without the use of an oxidizing precursor, such as O, HO, O, HO, O-containing plasma, oxygen radicals, or oxygen atoms.

[0127] In some embodiments, the capping layer can be deposited at the same temperature utilized to deposit the transition metal chalcogenide film. For example, the capping layer can be deposited at a temperature 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.

[0128] 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.

[0129] As a non-limiting example, FIG. 6 illustrates the environmental stability over time of both bare zirconium chalcogenide films deposited according to embodiments of the present disclosure and zirconium chalcogenide films capped with an aluminum silicate capping layer. More specifically, FIG. 6 illustrates the change in normalized X-ray diffraction (XRD) intensity of the (001) main peak versus time of exposure to environmental conditions for both aluminum silicate capped zirconium disulfide films (indicated by triangular data markers) and uncapped bare zirconium disulfide films (indicated by square data markers). Examination of the bare zirconium disulfide film data shows that the intensity of the (001) peak in the XRD data decreases over time, indicating that the bare zirconium disulfide is exposed to environmental conditions and oxidizes over time. In contrast, examination of the aluminum silicate capped zirconium disulfide film data shows no decrease in the intensity of the (001) peak in the XRD data over time, indicating substantially no oxidation of the capped zirconium disulfide film.

[0130] In some embodiments of the present disclosure, in situ deposition of a capping layer directly onto the surface of the transition metal chalcogenide film can be beneficial in improving the quality of the transition metal chalcogenide thin film because the capping layer may prevent oxidation of the chalcogenide film during cooling of the reaction chamber after deposition.

[0131] More specifically, FIG. 7A illustrates grazing incidence x-ray diffraction (GIXRD) data for exemplary zirconium disulfide films deposited using various numbers of deposition cycles without a capping layer, and FIG. 7B illustrates grazing incidence x-ray diffraction (GIXRD) data for exemplary zirconium chalcogenide films deposited using various numbers of deposition cycles with an in-situ capping layer deposited directly on the chalcogenide film. Examination of FIG. 7A, i.e., uncapped zirconium disulfide, shows that XRD peaks corresponding to crystalline zirconium disulfide do not appear until 1000 deposition cycles have been completed, which corresponds to a thickness of about 8 nanometers. In contrast, examination of FIG. 7B, i.e., capped zirconium disulfide, shows that XRD peaks corresponding to crystalline zirconium disulfide appear at 500 deposition cycles, which corresponds to a thickness of about 4 nanometers. Thus, in some embodiments of the present disclosure, the metal chalcogenide film may be covered with an in-situ capping layer, and the metal chalcogenide film may be crystalline with a thickness of less than about 5 nanometers, or less than about 4 nanometers, or less than about 2 nanometers, or less than about 1.5 nanometers, or even less than 1 nanometer.

[0132] Metal chalcogenide films deposited by the cyclic deposition processes disclosed herein can be utilized in a variety of contexts, for example, in the formation of semiconductor device structures. Those skilled in the art will recognize that the processes described herein are applicable in many contexts, including, but not limited to, the fabrication of transistors.

[0133] As a non-limiting example, referring to FIG. 8, a semiconductor device structure 800 can comprise a field effect transistor (FET) that can include a silicon substrate 802 and a silicon dioxide (SiO2) layer 804 disposed on the silicon substrate 802. The semiconductor device structure 800 can further comprise a source region 806 and a drain region 808. A transition metal chalcogenide film 810 deposited according to an embodiment of the present disclosure is disposed between the source region and the drain region. The transition metal chalcogenide film 810 can comprise a hafnium disulfide or zirconium disulfide film and can comprise a channel region of the FET structure. In some embodiments of the present disclosure, the transition metal chalcogenide film 810 can have a thickness of less than 10 nanometers, or less than 5 nanometers, or even less than 1 nanometer. A capping layer 811 can be disposed directly on the transition metal chalcogenide film 810. For example, the capping layer 811 can include a metal silicate film, specifically an aluminum silicate film. The semiconductor device structure 800 may further comprise a gate dielectric layer 812 disposed on the transition metal chalcogenide film 810, and the gate dielectric layer 812 may comprise hafnium dioxide (HfO2). The semiconductor device structure 800 may further comprise a gate electrode 814 disposed on the transition metal chalcogenide film 810.

[0134] The embodiments of the present disclosure may also include a reaction system configured to deposit the transition metal chalcogenide films of the present disclosure. More specifically, FIG. 9 illustrates a schematic of a reaction system 900 comprising a reaction chamber 902 for holding a substrate (not shown) under predetermined pressure, temperature, and environmental conditions, and further comprising mechanisms for selectively exposing the substrate to various gases. A precursor reactant source 904 may be coupled to the reaction chamber 902 by a conduit or other suitable means 904A, and may further be coupled to a manifold, valve control system, mass flow control system, or mechanism for controlling the gaseous precursors originating from the precursor reactant source 904. The precursors (not shown), reactants (not shown) provided by the precursor reactant source 904 may be liquids or solids under room temperature and standard atmospheric pressure conditions. Such precursors may be vaporized in a vacuum vessel of the reactant source, and the precursors may 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 902 through conduit 904A. In other embodiments, the 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. Conduit 904A may further comprise a gas purifier 905A for substantially removing undesirable contaminants from the vapor delivered to the reaction chamber 902.

[0135] As mentioned above, the reaction system 900 can also include an additional precursor reactant source, such as precursor reactant source 906, which can also be coupled to the reaction chamber 902 by a conduit 906A and an additional gas purifier 905B.

[0136] A purge gas source 908 is also coupled to the reaction chamber 902 through conduit 908A to selectively supply various inert or noble gases to the reaction chamber 902 to assist in the removal of precursor or waste gases from the reaction chamber. The various inert or noble gases that may be supplied may come from solid, liquid or stored gaseous forms.

[0137] The reaction system 900 of FIG. 9 may also include a system operation and control mechanism 910 that provides electronic circuitry and mechanical components for selectively operating the valves, manifolds, pumps, and other devices included in the reaction system 900. Such circuits and components operate to introduce precursors, purge gases from respective precursor sources 904, 906, and purge gas source 908. The system operation and control mechanism 910 also controls the timing of gas pulse sequences, substrate and reaction chamber temperatures, reaction chamber pressure, and various other operations required to properly operate the reaction system 900. The operation and control mechanism 910 may include control software and electrical or pneumatic control valves for controlling the flow of precursors, reactants, and purge gases into and out of the reaction chamber 902. The control system may include software or hardware components, such as modules, such as FPGAs or ASICs, that perform specific tasks. The modules are advantageously configured to reside on addressable storage media of the control system and may be configured to perform one or more processes.

[0138] Those skilled in the relevant art will appreciate that other configurations of the present reaction system are possible, including different numbers and types of precursor reactant and purge gas sources. Moreover, such skilled artisans will also appreciate that there are many 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 902. Moreover, as a simplified illustration of the reaction system, many components are omitted for ease of illustration. Such components may include, for example, various valves, manifolds, purifiers, heaters, reservoirs, vents, and / or bypasses.

[0139] 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, such as alternative useful combinations of the described elements. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

1. 1. A method for depositing a transition metal chalcogenide film on a substrate by a cyclic deposition process, the method comprising: contacting the substrate with at least one transition metal-containing gas phase reactant comprising at least one of a hafnium precursor or a zirconium precursor; contacting the substrate with at least one chalcogen-containing gas phase reactive material, wherein the temperature of the substrate during the contacting step is less than about 450° C.

2. The method of claim 1 , wherein the cyclical deposition process comprises atomic layer deposition.

3. The method of claim 1 , wherein the cyclic deposition process comprises cyclic chemical vapor deposition.

4. 10. The method of claim 1, wherein the hafnium precursor or the zirconium precursor comprises at least one of a halide precursor or a metal organic precursor.

5. The halide precursor is hafnium tetrachloride (HfCl ４ ) or zirconium tetrachloride (ZrCl ４ 5. The method of claim 4, further comprising at least one of:

6. The method of claim 4 , wherein the metallo-organic precursor comprises at least one of an alkylamide precursor or a cyclopentadienyl ligand-containing precursor.

7. The alkylamide precursor is tetrakis(ethylmethylamido)hafnium (Hf(NEtMe) ４ ), or tetrakis(ethylmethylamido)zirconium (Zr(NEtMe) ４ 7. The method of claim 6, comprising at least one of the following:

8. The cyclopentadienyl ligand-containing precursor is tris(dimethylamido)cyclopentadienylhafnium (HfCp(NMe ２ ) ３ ), bis(methylcyclopentadienyl)methoxymethylhafnium ((MeCp) ２ Hf(CH) ３ (O.C.H. ３ )), tris(dimethylamido)cyclopentadienyl zirconium (ZrCp(NMe ２ ) ３ ), or bis(methylcyclopentadienyl)methoxymethylzirconium ((MeCp) ２ Zr(CH) ３ (O.C.H. ３ 7. The method of claim 6, further comprising at least one of the following steps:

9. The at least one chalcogen-containing gas phase reactant is hydrogen sulfide (H ２ S), hydrogen selenide (H ２ Se), dimethyl sulfide ((CH ３ ) ２ S), or dimethyl telluride (CH ３ ) ２ The method of claim 1 comprising Te.

10. 10. The method of claim 1, further comprising flowing the chalcogen-containing gas-phase reactant through a gas purifier prior to entering the reaction chamber to reduce a concentration of at least one of water or oxygen in the chalcogen-containing gas-phase reactant.

11. 11. The method of claim 10, wherein a concentration of at least one of water or oxygen in the chalcogen-containing gas phase reactant is reduced to less than 1 ppm.

12. 10. The method of claim 1, further comprising flowing a carrier gas through a vessel housing a source of the transition metal-containing gas phase reactant to transport the transition metal-containing gas phase reactant to the reaction chamber, and further comprising flowing the carrier gas through a gas purifier prior to entering the source of the transition metal-containing gas phase reactant to reduce a concentration of at least one of water or oxygen in the carrier gas.

13. 13. The method of claim 12, wherein the concentration of at least one of water or oxygen in the carrier gas is reduced to less than 1 ppm.

14. The method of claim 1 , further comprising pre-annealing the reaction chamber at a temperature above 500° C. prior to film deposition.

15. The method of claim 1 , wherein the transition metal chalcogenide film comprises a (001) preferred crystal orientation.

16. 10. The method of claim 1, further comprising in situ depositing a capping layer on said transition metal chalcogenide film to substantially prevent oxidation of said transition metal chalcogenide film when exposed to environmental conditions.

17. 17. The method of claim 16, wherein in situ depositing a capping layer on the transition metal chalcogenide film further comprises depositing the capping layer utilizing a non-oxidizing precursor or a non-oxygen reactant.

18. The method of claim 16 , wherein the capping layer comprises a metal silicate film.

19. The metal silicate film is an aluminum silicate film (Al ｘ S ｙ O ｚ 20. The method of claim 18, comprising:

20. A semiconductor device structure comprising a transition metal chalcogenide film deposited by the method of claim 1.

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