ALD Deposition Using MoO2Cl2 and MoO2Br2

Abstract

The disclosed and claimed subject matter provides a method for growing a Mo precursor using MoO along with alkyl-chalcogenide, alkyl-dichalcogenide, and / or dihydro-chalcogenide precursors while maintaining the process in a self-limiting layer synthesis growth mode or a self-limiting layer synthesis-like growth mode. 2 Cl 2 and MoO 2 Br 2 2D MoX, which utilizes one or more of the following: 2 (X=S, Se or Te) by atomic layer deposition (ALD).

Description

[Technical field]

[0001] The disclosed and claimed subject matter relates to atomic layer deposition (ALD) of 2D MoX2 (X=S, Se, or Te) utilizing one or more of MoO2Cl2 and MoO2Br2 as Mo precursors along with alkyl-chalcogenide, alkyl-dichalcogenide, and / or dihydro-chalcogenide precursors while maintaining the process in a self-limiting layer synthesis growth mode or a self-limiting layer synthesis-like growth mode. [Background technology]

[0002] A variety of precursors may be used to form metal-chalcogenide thin films, and a variety of deposition techniques can be employed. Such techniques include reactive sputtering, ion-assisted deposition, sol-gel deposition, chemical vapor deposition (CVD) (including metalorganic CVD or MOCVD), and atomic layer deposition (ALD). CVD and ALD type processes are increasingly being used because they offer the advantages of improved composition control, high film uniformity, and effective doping control.

[0003] ALD deposition requires a vacuum reaction chamber with precursor lines that can flow into the reaction chamber using (i) vapor pressure ("vapor draw"), (ii) a carrier flowing through a precursor ampoule ("bubbling"), or (iii) a gas flow from a bottle, tank, or other source. In operation, a substrate is placed in the reaction chamber and a first precursor / reactant is flowed into the chamber for a time sufficient to saturate the substrate surface before evacuating the chamber using a purge gas flow ("first precursor pulse"). After the purge is complete, a second precursor / reactant is flowed into the chamber for a time sufficient to saturate the substrate surface previously coated with the first precursor molecules ("second precursor pulse"). This is followed by a second purge step. The second purge step completes the two-precursor reaction cycle. At this point, the cycle is repeated from the beginning and is performed as many times as necessary to meet the desired film thickness. When operating at high pressure, a pressure stabilization step can be added between the end of the purge and the next pressure precursor pulse. In general, ALD mode requires that the precursor does not or cannot decompose. For most precursors, this introduces a CVD component into the ALD process, adversely affecting the ALD properties of the process and the purity of the deposited film. The growth curve (thickness vs. ALD cycle number) is most commonly a linear curve, or if there is some CVD component, it can also be a super-linear growth curve (having quadratic or higher terms in the ALD cycle number in the thickness vs. ALD cycle number fit). It is never asymptotic or sub-linear in nature (at least not intentionally).

[0004] CVD is another chemical process. In this case, precursors are used to form a thin film on the substrate surface. In a typical CVD process with two or more precursors, the precursors are introduced together into the chamber, or at least with a deliberate overlap to react in the gas phase or at the wafer surface. There are CVD processes with one precursor that decomposes to produce a deposited film on the substrate, e.g., SiH4 that decomposes to produce a Si film. In either case, the precursor is delivered to the surface of the substrate (e.g., wafer) in a low-pressure or ambient pressure reactor. The precursor reacts and / or decomposes in the gas phase or on the wafer surface, and this material is deposited on the substrate surface to form a thin film of the deposited material. In CVD, there can be surface reactions, but most CVD is different from ALD in that it involves pre-reactions or pre-decomposition in the gas phase. In ALD, the decomposition reaction is exclusively a surface reaction. Volatile by-products are removed by gas flow through the reactor. The deposited film thickness can be difficult to control. Because the film thickness depends on many parameters, such as temperature, pressure, gas flow and uniformity, chemical depletion effects, and time coordination. CVD processes can be performed thermally or in plasma-enhanced mode, and usually require higher temperatures (at or above the precursor decomposition temperature) and / or activated plasma conditions to ensure decomposition and / or gas-phase reactions. Therefore, CVD processes usually require more complex hardware than thermal ALD processes. In CVD processes, the more precursor (longer pulse or higher flux), the more film. In this case, there is no asymptotic limit to growth or soft saturation (saturation to a significantly slower linear growth) with increasing precursor time or flux.

[0005] The ever-shrinking size of microelectronic components, e.g., semiconductor devices, presents several technological challenges and drives the need for improved thin-film technologies. Specifically, thin, highly mobile semiconductor deposition with self-limiting growth to excellent conformality and uniform thickness is important to enable the enhancement of transistor channels in various devices. Thickness and uniformity control is essential in transistor channels, e.g., 3D NAND cells, as well as advanced logic transistors, including finFET and GAA devices, where Si body thickness reaches 2.5 nm or less. CVD and ALD are particularly attractive for fabricating conformal transition metal dichalcogenide (TMD) films on substrates, e.g., silicon, silicon oxide, metal nitrides, metal oxides, and other layers. As mentioned above, in these techniques, vapors of volatile metal complexes are introduced into a process reactor. In the process reactor, the vapor reacts in the gas phase and upon contact with the surface of the silicon wafer, a chemical reaction occurs that deposits a thin film (e.g., for CVD, disilane+H2 gas can be injected into a thermal CVD chamber with the wafer heated to deposition temperature for as long as desired), or individual precursors react in a reaction sequence on the surface in separate steps (e.g., for ALD, a trimethylaluminum pulse+purge followed by a H2O pulse can be performed and repeated for as many cycles as desired). CVD occurs when the precursor reacts thermally at the wafer surface or with reagents simultaneously added into the process reactor, and film growth occurs in a steady-state deposition. CVD can be applied in a continuous or pulsed mode to achieve the desired film thickness and contamination levels. In ALD, precursors are chemisorbed onto the wafer as a self-saturating monolayer, excess unreacted precursor along with reaction by-products are purged with an inert gas, and then an excess of reactant reagent is added to react with the chemisorbed precursor monolayer to form a material (metal, non-metal, dielectric, etc.).Such an inert gas is understood to be one of nitrogen, argon, neon, helium, krypton, or xenon, or a mixture of any combination of these gases in any ratio. Excess reagents and reaction by-products are then purged with the inert gas. This cycle can then be repeated multiple times to build up the film to the desired thickness with atomic precision, since the chemisorption of the precursors and reagents is self-limiting, producing a linear growth curve of thickness versus number of ALD cycles. ALD offers the deposition of ultra-thin yet continuous films with precise control of film thickness, excellent film thickness uniformity, and remarkably conformal film growth to uniformly cover deeply etched and highly intricate structures, such as interconnect vias and trenches. Therefore, ALD is typically preferred for depositing thin films on high aspect ratio features. However, the well-known ALD growth of MoX2 films could only be achieved at temperatures below about 350° C. (except for MoCl5+H2S), and these low temperatures resulted in poor stoichiometry and / or poor crystallinity, which made these ALD processes unfeasible.

[0006] MoCl5+H2S has been identified in the literature as a process that can be grown in a "self-limiting-layer-synthesis" deposition mode, where the growth curve is not linear or superlinear and the thickness saturates asymptotically with increasing number of ALD cycles of MoCl5+H2S in the ALD mode of operation (DOI:10.1038 / srep1875), but no additional examples of such a process can be found. In addition, if such processes could be identified, they would be expected to be in molybdenum chlorides, fluorides, bromides, or iodides other than molybdenum halide precursors, such as MoO2Cl2, precursors with two-thirds of the Mo bonds captured by oxygen atoms. Thus, until now, the ability to grow self-limiting layer synthesis MoX2 films at higher temperatures has been limited to using MoCl5+H2S→MoS2. This not only limited the X in MoX2, but also resulted in the process being significantly more corrosive / acidic to the ALD or CVD chamber hardware than was the case for MoO2Cl2.

[0007] It would be highly desirable to be able to achieve the growth of Mo-based 2D TMD films (other than MoS2 films) using a new precursor set in an ALD mode of operation. This would allow for the use of higher temperatures than those currently described and known for the deposition of ALD films, while utilizing a wide variety of chalcogenide precursors. Growing Mo-based 2D TMD films in a manner that also allows growth via a "self-limiting-layer-synthesis" or "self-limiting-layer-synthesis-like" deposition mode (where the thickness has a soft saturation state with the ALD cycle rather than a purely asymptotic curve) would allow control over the number of monolayers, as well as improvements in grain size and overall semiconducting quality of the film. The key here is to balance the relative proportions of the deposition and etching components of the growth process. This can be adjusted by varying the chalcogenide precursors. The use of MoO2Cl2 as an ALD molybdenum precursor for 2D TMD growth enables deposition and etch rates that allow any of the chalcogenide precursors described herein to exhibit self-limiting layer synthesis growth or self-limiting layer synthesis-like growth for the resulting 2D TMDs. In addition, the deposited films also exhibit significantly lower etch rates than the MoCl5 precursor previously used in TMD processes.

[0008] In view of the above, the disclosed and claimed subject matter enables self-limiting Mo-based TMD films to be formed at desired operating conditions. Specifically, the subject matter provides methods for growing different Mo films and / or different film thicknesses at deposition conditions (e.g., temperature, pressure, flow rate, ampoule temperature, etc.) that are the same or similar to those used to deposit MoCl5+H2S, without the inherent corrosiveness limitations of molybdenum pentachloride, and without being limited to only MoS2 for TMDs. Summary of the Invention

[0009] In one embodiment, the disclosed and claimed subject matter relates to an ALD deposition method using one or more of MoO2Cl2 and MoO2Br2 and one or more chalcogenide precursors of formula (i) R1XR2 and / or formula (ii) R1XXR2, where X=S, Se, or Te, and R1 and R2 are each independently one of hydrogen, unsubstituted linear C1-C6 alkyl group, linear C1-C6 alkyl group substituted with one or more halogens, linear C1-C6 alkyl group substituted with an amino group, unsubstituted branched C3-C6 alkyl group, branched C3-C6 alkyl group substituted with one or more halogens, branched C3-C6 alkyl group substituted with an amino group, unsubstituted amine, substituted amine, and -Si(CH3)3.

[0010] In one aspect of this embodiment, the ALD deposition is carried out under conditions that result in “self-limiting layer synthesis” and / or “self-limiting layer synthesis-like” conditions for growing a 2D MoS 2 , 2D MoSe 2 , or 2D MoTe 2 layer.

[0011] In another aspect of this embodiment, the ALD deposition provides “self-limiting layer synthesis” or “self-limiting layer synthesis-like” conditions for the deposited MoX2 film that exhibits high quality crystalline order in the grown semiconductor film along with increased electron and / or hole mobility that is beneficial in semiconductors due to the reduction of vacancy sites, particularly chalcogen vacancy sites, in the MoX2 lattice.

[0012] In another aspect of this embodiment, the ALD operating conditions are "balanced" to provide a "self-limiting layer synthesis" or "self-limiting layer synthesis-like" deposition, i.e., the chlorine atoms in the MoO2Cl2 precursor and in the chloride of the ligand of the chalcogenide precursor after the ligand exchange reaction are balanced. In this aspect of the disclosed and claimed subject matter, these chlorine atoms not only add an etching component, but also behave as a mild Cl dopant in the deposited film, helping to improve the electrical properties of the semiconducting MoX2 film.

[0013] In another aspect of this embodiment, the ALD deposition temperature window ranges from about 100° C. to about 650° C. and the pressure ranges from about 0.1 to about 100 Torr. In a further aspect, the deposition temperature and pressure are tailored to the chalcogenide precursor selected.

[0014] In another aspect of this embodiment, the substrate surface is pretreated with one or more chemical recipes and / or plasma process preparations described herein prior to deposition of the MoX2 film.

[0015] This Summary section does not identify any embodiments and / or additional novel aspects of the disclosed and claimed subject matter. Rather, this Summary merely provides a preliminary discussion of various different embodiments and merits of novelty over conventional and known techniques. For further details and / or possible overviews of the disclosed and claimed subject matter and embodiments, the reader is directed to the Detailed Description and corresponding Figures of the Disclosure further below.

[0016] The order of discussion of the different steps described herein is presented for purposes of clarity. In general, the steps disclosed herein can be performed in any suitable order. In addition, although each of the different features, techniques, configurations, etc. disclosed herein may be discussed in different places in this disclosure, it is understood that each of the concepts can be performed independently of each other or in combination with each other as appropriate. Thus, the disclosed and claimed subject matter can be embodied and viewed in many different ways.

[0017] The accompanying drawings, which provide a further understanding of the disclosed subject matter and which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosed subject matter and, together with the description, serve to explain the principles of the disclosed subject matter. [Brief description of the drawings]

[0018] [Figure 1] FIG. 1 illustrates the ALD growth of MoSe2 using MoO2Cl2+iPr2Se at 450° C. in one embodiment (Example 1) of the disclosed and claimed subject matter. [Diagram 2] FIG. 2 illustrates that the disclosed and claimed ALD process exhibits a flat deposition rate throughout the ALD deposition window. [Diagram 3] FIG. 3 illustrates that the disclosed and claimed ALD process exhibits self-limiting layer synthesis behavior in its growth curve. [Figure 4] FIG. 4 shows the Raman spectroscopic characteristics of a MoSe2 film formed according to the disclosed and claimed ALD process. [Diagram 5] FIG. 5 shows Raman FWHM (full width at half maximum of the Raman peak) versus deposition temperature over the entire growth curve (left image shows A1g FWHM versus ALD cycle number at two temperatures, right image shows XPS Se / Mo ratio versus cycle number at two temperatures). [Figure 6] FIG. 6 shows a DEDS saturation curve illustrating the saturation of MoS2 at about 3 s DEDS pulse length using MoO2Cl2+Et2S2 in one embodiment (Example 2) of the disclosed and claimed subject matter. [Figure 7] FIG. 7 shows the saturation curves of Example 2, showing saturation at about 3 s MoO2Cl2 pulse length. [Figure 8] FIG. 8 illustrates the temperature window for Example 2 that results in a relatively constant thickness versus temperature for the saturation process. [Figure 9] FIG. 9 shows that the ALD MoO2Cl2+Et2S2 growth curve of Example 2 exhibits soft saturation behavior, which is a self-limiting layer synthesis-like behavior. [Figure 10] FIG. 10 shows plots of Raman A1g and E2g FWHM versus ALD cycle number for the sample of Example 2, with full spectra displayed at 50 and 500 cycles, demonstrating the improvement in FWHM at the optimal cycle count. [Figure 11] FIG. 11 shows an SEM showing the growth of MoS2 without fins. [Figure 12] FIG. 12 is a TEM image showing the growth of MoS2 without fins. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] definition Unless otherwise stated, the following terms used in the specification and claims shall have the following meanings with respect to this application.

[0020] In this application, the use of the singular includes the plural, and "a," "an," and "the" mean "at least one" unless otherwise specified. Furthermore, the use of the term "including," as well as other forms such as "includes" and "included," is non-limiting. Also, terms such as "element" or "component" include both elements or components that contain one unit and elements or components that contain two or more units, unless otherwise specified. Unless otherwise specified, the conjunction "and" as used herein is intended to be inclusive, and the conjunction "or" is not intended to be exclusive. For example, the phrase "or, alternatively" is intended to be exclusive. As used herein, the term "and / or" refers to any combination of the preceding elements, including the use of a single element.

[0021] The terms "about" or "approximately," when used in connection with a measurable, numerical variable, refer to the indicated value of the variable and all values ​​of the variable that are within experimental error of the indicated value (e.g., within a 95% confidence limit for the mean) or within a percentage of the indicated value (e.g., ±10%, ±5%), whichever is greater.

[0022] As used herein, "C x-y " (x and y are each integers) specifies the number of carbon atoms in the chain. For example, C 1-6 Alkyl means an alkyl chain having from 1 to 6 carbon atoms (e.g., methyl, ethyl, propyl, butyl, pentyl, and hexyl). Unless otherwise specified, the chain can be straight or branched.

[0023] Unless otherwise specified, "alkyl" refers to a hydrocarbon group that may be linear, branched (e.g., methyl, ethyl, propyl, isopropyl, tert-butyl, and the like), cyclic (e.g., cyclohexyl, cyclopropyl, cyclopentyl, and the like), or polycyclic (e.g., norbornyl, adamantly, and the like). Suitable acyclic groups may be methyl, ethyl, n- or iso-propyl, n-, iso, or tert-butyl, linear or branched pentyl, hexyl, heptyl, octyl, decyl, dodecyl, tetradecyl, and hexadecyl. Unless otherwise specified, alkyl is a 1-10 carbon atom moiety. Cyclic alkyl groups may be monocyclic or polycyclic. Suitable examples of monocyclic alkyl groups include substituted cyclopentyl, cyclohexyl, and cycloheptyl groups. As described herein, cyclic alkyl groups may have any of the acyclic alkyl groups as a substituent. The alkyl moieties may be substituted or unsubstituted.

[0024] "Halogenated alkyl" refers to a linear, cyclic, or branched saturated alkyl group, as defined above, in which one or more of the hydrogens have been replaced by a halogen (e.g., F, Cl, Br, and I). Thus, for example, fluorinated alkyl (also known as "fluoroalkyl") refers to a linear, cyclic, or branched saturated alkyl group, as defined above, in which one or more of the hydrogens have been replaced by a fluorine (e.g., trifluoromethyl, perfluoroethyl, 2,2,2-trifluoroethyl, perfluoroisopropyl, perfluorocyclohexyl, and the like). Such haloalkyl moieties (e.g., fluoroalkyl moieties), provided they are not per / polyhalogenated, may be unsubstituted or may be further substituted.

[0025] "Alkoxy" (also known as "alkyloxy") means an alkyl group, as defined above, attached through an oxy (-O-) moiety (e.g., methoxy, ethoxy, propoxy, butoxy, 1,2-isopropoxy, cyclopentyloxy, cyclohexyloxy, and the like). These alkoxy moieties may be substituted or unsubstituted.

[0026] "Alkylcarbonyl" refers to an alkyl group, as defined above, attached through a carbonyl group (-C(=O-)) moiety (e.g., methylcarbonyl, ethylcarbonyl, propylcarbonyl, butylcarbonyl, cyclopentylcarbonyl, and the like). These alkylcarbonyl moieties may be substituted or unsubstituted.

[0027] "Halo" or "halide" means halogen (e.g., F, Cl, Br, and I).

[0028] "Hydroxy" (also known as "hydroxyl") means the --OH group.

[0029] The term "aryl" refers to an aromatic cyclic functional group having 4 to 10 carbon atoms, 5 to 10 carbon atoms, or 6 to 10 carbon atoms. Exemplary aryl groups include, but are not limited to, phenyl, 1-phenylethyl (Ph(Me)CH-), 1-phenyl-1-methyl-ethyl (Ph(Me)2C-), benzyl, chlorobenzyl, tolyl, O-xylyl, 1,2,3-triazolyl, pyrrolyl, and furanyl.

[0030] Unless otherwise noted, the term "substituted" when referring to alkyl, alkoxy, fluorinated alkyl, and the like, means one of these moieties that further contains one or more substituents. These substituents include, but are not limited to, the following substituents: alkyl, substituted alkyl, unsubstituted aryl, substituted aryl, alkyloxy, alkylaryl, haloalkyl, halide, hydroxy, amino, and aminoalkyl. Similarly, the term "unsubstituted" refers to these same moieties in which there are no substituents apart from hydrogen.

[0031] For purposes of this invention and the claims thereto, the numbering of the Periodic Table Groups follows the IUPAC Periodic Table of Elements.

[0032] As used herein, "and / or" in expressions such as "A and / or B" is intended to include "A and B," "A or B," or "A" and "B."

[0033] The terms "substituents," "radicals," "groups," and "moieties" may be used interchangeably.

[0034] As used herein, the terms "metal-containing complex" (or more simply "complex") and "precursor" are used interchangeably and refer to a metal-containing molecule or compound that can be used to prepare a metal-containing film by a vapor deposition process, such as ALD or CVD. The metal-containing complex can be deposited on, adsorbed onto, decomposed on, delivered to, and / or delivered to a substrate or substrate surface to form a metal-containing film. In one or more embodiments, the metal-containing complexes disclosed herein are metal oxyhalide complexes, specifically molybdenum oxychloride complexes.

[0035] The term “ALD” as used herein means a self-limiting deposition process, including, but not limited to, a) a process in which reactants including a vapor containing MoO2Cl2 precursor and a chalcogenide precursor are sequentially introduced into a reactor, such as a single-wafer ALD reactor, a quasi-batch ALD reactor, or a batch furnace ALD reactor, and b) a process in which reactants including a vapor containing MoO2Cl2 precursor and a chalcogenide precursor are exposed to the substrate by moving or rotating the substrate into various sections of the reactor, and the sections are separated by an inert gas curtain, i.e., a spatial ALD reactor or a roll-to-roll ALD reactor.

[0036] The term "metal-containing film" as used herein includes not only elemental metal films, as more fully defined below, but also films that include a metal with one or more elements, such as metal oxide films, metal nitride films, metal silicide films, metal carbide films, metal sulfide films, metal selenide films, metal tellurides, and the like.

[0037] As used herein, the term "vapor deposition process" is used to mean any type of vapor deposition technique, including, but not limited to, CVD and ALD. In various embodiments, CVD may take the form of conventional (i.e., continuous flow) CVD, liquid injection CVD, or light-assisted CVD. CVD may take the form of a pulsed technique, i.e., pulsed CVD. ALD is used to form a metal-containing film by evaporating and / or delivering at least one metal complex disclosed herein to a substrate surface. For conventional ALD processes, see, for example, George SM, et al. J.Phys.Chem., 1996, 100, 13121-13131. In other embodiments, ALD may take the form of conventional (i.e., pulsed injection) ALD, liquid injection ALD, light-assisted ALD, plasma-assisted ALD, or plasma-promoted ALD. The term "vapor deposition process" further includes various vapor deposition techniques described in Chemical Vapour Deposition: Precursors, Processes, and Applications; Jones, AC; Hitchman, ML, Eds. The Royal Society of Chemistry: Cambridge, 2009; Chapter 1, pp. 1-36.

[0038] As used herein, the term "feature" refers to an opening in a substrate that may be defined by one or more sidewalls, a bottom surface, and an upper corner. In various embodiments, a feature may be a via, a trench, a contact, a dual damascene, etc.

[0039] As used herein, the terms "selective growth," "selectively grown," and "selectively grown" may be used interchangeably to mean growth of a film on at least a portion of a first substrate and substantially no growth on the remainder of the first substrate, and a greater amount of film growth on at least a portion of the first substrate compared to the amount of film growth on the remainder of the first substrate. For example, selective growth may include growth of a film on a lower portion of a feature versus less or no film growth occurring on an upper portion of the feature or outside of the feature. In the context of two or more substrates, the terms "selective growth," "selectively grown," and "selectively grown" also include growth of a film on a first substrate and substantially no growth on a second substrate (or a third substrate, or a fourth substrate, or a fifth substrate, etc.) and also include a greater amount of film growth on the first substrate than on the second substrate (or a third substrate, or a fourth substrate, or a fifth substrate, etc.).

[0040] MoO2Cl2 and / or MoO2Br2, and one or more chalcogenide precursors according to the disclosed and claimed subject matter are preferably substantially free of water. As used herein, the term "substantially free" with respect to water means less than 5000 ppm (by weight) as measured by proton NMR or Karl Fischer titration, preferably less than 3000 ppm as measured by proton NMR or Karl Fischer titration, and more preferably less than 1000 ppm as measured by proton NMR or Karl Fischer titration, and most preferably less than 100 ppm as measured by proton NMR or Karl Fischer titration. MoO2Cl2 and one or more chalcogenide precursors also preferably contain metal ions or metals, such as Li + (Li), Na + (Na), K + (K), Mg 2+ (Mg), Ca 2+ (Ca), Al 3+ (Al), Fe 2+ (Fe), Fe 3+ (Fe), Ni 2+(Fe), Cr 3+ The MoO2Cl2 and / or MoO2Br2 are substantially free of Cr, Ti, V, Mn, Co, Co, Ni, Cu, or Zn. These metal ions or metals potentially originate from the starting materials / reactors employed to synthesize MoO2Cl2 and one or more chalcogenide precursors. The term "substantially free" as used herein in relation to Li, Na, K, Mg, Ca, Al, Fe, Ni, Cr, Ti, V, Mn, Co, Ni, Cu, or Zn means less than 5 ppm (by weight), preferably less than 3 ppm, and more preferably less than 1 ppm, and most preferably 0.1 ppm, as measured by ICP-MS. In addition, MoO2Cl2 and / or MoO2Br2, and one or more chalcogenide precursors are preferably substantially free of organic impurities originating from the starting materials employed during the synthesis or from by-products produced during the synthesis. Examples include, but are not limited to, alkanes, alkenes, alkynes, dienes, ethers, esters, acetates, amines, ketones, amides, and aromatic compounds. As used herein, the term "free" of organic impurities means less than 1000 ppm as measured by GC, preferably less than 500 ppm (by weight) as measured by GC, and most preferably less than 100 ppm (by weight) as measured by GC or other analytical methods for assay. What is important is that MoO2Cl2 and one or more chalcogenide precursors preferably have a purity of 98 wt% or more, more preferably 99 wt% or more, as measured by GC when used as precursors to deposit Mo-containing films.

[0041] The section headings used herein are for organizational purposes and should not be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application, including but not limited to patents, patent applications, articles, books, and papers, are expressly incorporated herein by reference in their entirety for all purposes. In the event that the incorporated literature and similar materials define a term in a manner that is inconsistent with the definition of that term in this application, this application will control.

[0042] It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory, and are not intended to limit the subject matter, as claimed. The objects, features, advantages, and ideas of the disclosed subject matter will be apparent to those skilled in the art from the description provided in the specification, and the disclosed subject matter can be readily implemented by those skilled in the art based on the description appearing herein. Any "preferred embodiments" and / or descriptions of examples illustrating a preferred mode for implementing the disclosed subject matter are included for illustrative purposes and are not intended to limit the scope of the claims.

[0043] It will also be apparent to those skilled in the art that various modifications may be made to the disclosed subject matter based on the embodiments described in the specification without departing from the spirit and scope of the subject matter disclosed herein.

[0044] As mentioned above, the disclosed subject matter relates to ALD deposition processes using MoO2Cl2 and / or MoO2Br2 and one or more chalcogenide precursors of (i) RXR2 and / or formula (ii) R1XXR2, where X=S, Se, or Te, and R1 and R2 are each independently one of hydrogen, unsubstituted linear C1-C6 alkyl group, linear C1-C6 alkyl group substituted with one or more halogens, linear C1-C6 alkyl group substituted with an amino group, unsubstituted branched C3-C6 alkyl group, branched C3-C6 alkyl group substituted with one or more halogens, branched C3-C6 alkyl group substituted with an amino group, unsubstituted amine, substituted amine, and -Si(CH3)3. In one embodiment, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl. In one embodiment, the process includes using MoO2Cl2. In one embodiment, the process includes using MoO2Br2. Specific aspects of the disclosed and claimed ALD processes are described below.

[0045] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing a Mo-containing film using MoO2Cl2 and one or more chalcogenide precursors of formula (i) R1XR2 and / or (ii) R1XXR2, where X=S, Se, or Te, and R1 and R2 are each independently one of hydrogen, a linear C1-C6 alkyl group that is unsubstituted, a linear C1-C6 alkyl group that is substituted with one or more halogens, a linear C1-C6 alkyl group that is substituted with an amino group, a branched C3-C6 alkyl group that is unsubstituted, a branched C3-C6 alkyl group that is substituted with one or more halogens, a branched C3-C6 alkyl group that is substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH3)3. In one aspect of this embodiment, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl. The method includes (i) contacting a substrate with MoO2Cl2 vapor in a deposition reactor, (ii) purging any unreacted MoO2Cl2 with an inert gas, (iii) contacting a substrate with a chalcogenide precursor of the above formula in a deposition reactor, and (iv) optionally purging any unreacted chalcogenide precursor with an inert gas. In a further aspect of this embodiment, the method consists essentially of steps (i), (ii), (iii), and (iv). In a further aspect of this embodiment, the method consists of steps (i), (ii), (iii), and (iv).

[0046] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing a Mo-containing film using MoO2Cl2 and one or more chalcogenide precursors of formula (i) R1XR2 and / or (ii) R1XXR2, where X=S, Se, or Te, and R1 and R2 are each independently one of hydrogen, a linear C1-C6 alkyl group that is unsubstituted, a linear C1-C6 alkyl group that is substituted with one or more halogens, a linear C1-C6 alkyl group that is substituted with an amino group, a branched C3-C6 alkyl group that is unsubstituted, a branched C3-C6 alkyl group that is substituted with one or more halogens, a branched C3-C6 alkyl group that is substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH3)3. In one aspect of this embodiment, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl. The method includes (i) contacting a substrate with MoO2Cl2 vapor in a deposition reactor, (ii) purging any unreacted MoO2Cl2 with an inert gas, (iii) contacting a substrate with a chalcogenide precursor of the above formula in a deposition reactor, (iv) optionally purging any unreacted chalcogenide precursor with an inert gas, and (v) treating the substrate with H2S gas and / or H2S plasma to remove residual oxygen. In a further aspect of this embodiment, the method consists essentially of steps (i), (ii), (iii), (iv), and (v). In a further aspect of this embodiment, the method consists of steps (i), (ii), (iii), (iv), and (v).

[0047] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing a Mo-containing film using MoO2Br2 and one or more chalcogenide precursors of formula (i) R1XR2 and / or (ii) R1XXR2, where X=S, Se, or Te, and R1 and R2 are each independently one of hydrogen, a linear C1-C6 alkyl group unsubstituted, a linear C1-C6 alkyl group substituted with one or more halogens, a linear C1-C6 alkyl group substituted with an amino group, a branched C3-C6 alkyl group unsubstituted, a branched C3-C6 alkyl group substituted with one or more halogens, a branched C3-C6 alkyl group substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH3)3. In one aspect of this embodiment, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl. The method includes (i) contacting a substrate with MoO2Br2 vapor in a deposition reactor, (ii) purging any unreacted MoO2Cl2 with an inert gas, (iii) contacting a substrate with a chalcogenide precursor of the above formula in a deposition reactor, and (iv) optionally purging any unreacted chalcogenide precursor with an inert gas. In a further aspect of this embodiment, the method consists essentially of steps (i), (ii), (iii), and (iv). In a further aspect of this embodiment, the method consists of steps (i), (ii), (iii), and (iv).

[0048] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing a Mo-containing film using MoO2Br2 and one or more chalcogenide precursors of formula (i) R1XR2 and / or formula (ii) R1XXR2, where X=S, Se, or Te, and R1 and R2 are each independently one of hydrogen, a linear C1-C6 alkyl group that is unsubstituted, a linear C1-C6 alkyl group that is substituted with one or more halogens, a linear C1-C6 alkyl group that is substituted with an amino group, a branched C3-C6 alkyl group that is unsubstituted, a branched C3-C6 alkyl group that is substituted with one or more halogens, a branched C3-C6 alkyl group that is substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH3)3. In one aspect of this embodiment, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl. The method includes (i) contacting a substrate with MoO2Br2 vapor in a deposition reactor, (ii) purging any unreacted MoO2Br2 with an inert gas, (iii) contacting a substrate with a chalcogenide precursor of the formula above in a deposition reactor, (iv) optionally purging any unreacted chalcogenide precursor with an inert gas, and (v) treating the substrate with H2S gas and / or H2S plasma to remove residual oxygen. In a further aspect of this embodiment, the method consists essentially of steps (i), (ii), (iii), (iv), and (v). In a further aspect of this embodiment, the method consists of steps (i), (ii), (iii), (iv), and (v).

[0049] In one embodiment, the substrate surface can be pretreated with one or more chemical recipes and / or plasma process preparation prior to MoX2 deposition.

[0050] Delivery of MoO2Cl2 and / or MoO2Br2 As mentioned above, step (i) of the disclosed and claimed method includes contacting a substrate with one or more of MoO2Cl2 and MoO2Br2 vapor. MoO2Cl2 and / or MoO2Br2 are eminently suitable for use as volatile precursors for ALD and / or plasma enhanced atomic layer deposition (PEALD). As used herein, the term "atomic layer deposition process" refers to a self-limiting (i.e., film thickness asymptotically saturates after a certain number of cycles) sequential chemistry that deposits material films onto substrates having different compositions.

[0051] As will be apparent to one skilled in the art, when delivering MoO2Cl2 and / or MoO2Br2 precursors, factors such as the pulse time of MoO2Cl2 and / or MoO2Br2 precursors, the vapor pressure of MoO2Cl2 and / or MoO2Br2, and the carrier flow rate of MoO2Cl2 and / or MoO2Br2 to determine the arrival rate of MoO2Cl2 and / or MoO2Br2 molecules entering the chamber, as well as the total dose of MoO2Cl2 and / or MoO2Br2 molecules entering the chamber can be adjusted to balance these factors. For example, increasing the vapor pressure by a factor of two while shortening the pulse time by a factor of two will keep the MoO2Cl2 and / or MoO2Br2 dose constant while still changing the arrival rate of MoO2Cl2 and / or MoO2Br2 molecules. The co-variation of these three variables determines the total dose of MoO2Cl2 and / or MoO2Br2 into the chamber, the flux rate of MoO2Cl2 and / or MoO2Br2 molecules into the chamber, the time each MoO2Cl2 and / or MoO2Br2 molecule is allowed to evaporate within the MoO2Cl2 and / or MoO2Br2 ampoule, and any carrier gas turbulence within the MoO2Cl2 and / or MoO2Br2 ampoule.

[0052] In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 0.1 seconds to about 25 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 0.3 seconds to about 18 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 1 second. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 2 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 3 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 4 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 5 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 6 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 7 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 8 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 10 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 12 seconds. In another embodiment, the vapor pulse time of MoO2Cl2 and / or MoO2Br2 is about 15 seconds.

[0053] The ampoule temperature of MoO2Cl2 and / or MoO2Br2 is used to control the vapor pressure of MoO2Cl2 and / or MoO2Br2. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 55°C to about 300°C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 60°C to about 160°C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 65°C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 75°C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 85°C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 90°C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 115° C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 130° C. In another embodiment, the ampoule temperature of MoO2Cl2 and / or MoO2Br2 is about 150° C.

[0054] In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 5 sccm to about 3000 sccm. In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 30 sccm to about 1000 sccm. In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 50 sccm. In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 75 sccm. In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 100 sccm. In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 150 sccm. In another embodiment, the carrier gas flow rate of MoO2Cl2 and / or MoO2Br2 is about 200 sccm. In another embodiment, the carrier gas flow rate for MoO2Cl2 and / or MoO2Br2 is about 350 sccm. In another embodiment, the carrier gas flow rate for MoO2Cl2 and / or MoO2Br2 is about 500 sccm. In another embodiment, the carrier gas flow rate for MoO2Cl2 and / or MoO2Br2 is about 650 sccm.

[0055] In one embodiment, the MoO2Cl2 and / or MoO2Br2 vapors are separated from the other precursor materials before and / or during their introduction into the reactor. This process avoids pre-reaction of the metal precursor with any other materials.

[0056] In another embodiment, MoO2Cl2 and / or MoO2Br2 vapor is instead exposed to the substrate together with other reactants (e.g., ammonia vapor, and / or other precursors or reagents). This process allows film growth to proceed by self-limiting control of the surface reactions, the pulse length of each precursor or reagent, and the deposition temperature. It should be noted, however, that film growth stops when the surface of the substrate is saturated with MoO2Cl2 and / or MoO2Br2 vapor.

[0057] In another embodiment, a flow of argon and / or other gas is employed as a carrier gas to help deliver MoO2Cl2 and / or MoO2Br2 vapor to the reactor during precursor pulsing.

[0058] MoO2Cl2 and / or MoO2Br2 purging step. Step (ii) of the disclosed and claimed method includes purging any unreacted MoO2Cl2 and / or MoO2Br2 with an inert gas, which removes excess unabsorbed complex from the process reactor.

[0059] In one embodiment, the purge time is from about 1 second to about 90 seconds. In one embodiment, the purge time is from about 10 seconds to about 90 seconds. In one embodiment, the purge time is from about 15 seconds to about 60 seconds. In another embodiment, the purge time is about 20 seconds. In another embodiment, the purge time is about 30 seconds. In another embodiment, the purge time is about 40 seconds. In another embodiment, the purge time is about 60 seconds.

[0060] In one embodiment, the purge gas comprises argon, hi another embodiment, the purge gas comprises nitrogen.

[0061] Chalcogenide Precursors As stated above, step (iii) of the disclosed and claimed method comprises contacting the substrate with a chalcogenide precursor in a deposition reactor for a predetermined time. In one embodiment, the chalcogenide precursor has the formula (i) R1XR2 and / or the formula (ii) R1XXR2, where X=S, Se or Te, and R1 and R2 are each independently one of an unsubstituted linear C1-C6 alkyl group, a linear C1-C6 alkyl group substituted with one or more halogens, a linear C1-C6 alkyl group substituted with an amino group, an unsubstituted branched C3-C6 alkyl group, a branched C3-C6 alkyl group substituted with one or more halogens, a branched C3-C6 alkyl group substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH3)3. In one embodiment, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl. Specific aspects of the disclosed and claimed ALD processes are described below.

[0062] In one aspect of this embodiment, the chalcogenide precursor has the formula (i) R1XR2, where X=S, Se, or Te, and R1 and R2 are each independently one of an unsubstituted linear C1-C6 alkyl group, a linear C1-C6 alkyl group substituted with one or more halogens, a linear C1-C6 alkyl group substituted with an amino group, an unsubstituted branched C3-C6 alkyl group, a branched C3-C6 alkyl group substituted with one or more halogens, a branched C3-C6 alkyl group substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH3)3. In a further aspect, R1 and R2 are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl.

[0063] In another aspect of this embodiment, the chalcogenide precursor has the formula (ii) RXXR, where X=S, Se, or Te, and R and R are each independently one of an unsubstituted linear C-C alkyl group, a linear C-C alkyl group substituted with one or more halogens, a linear C-C alkyl group substituted with an amino group, an unsubstituted branched C-C alkyl group, a branched C-C alkyl group substituted with one or more halogens, a branched C-C alkyl group substituted with an amino group, an unsubstituted amine, a substituted amine, and -Si(CH). In a further aspect, in one embodiment, R and R are each independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl.

[0064] In one aspect of the above embodiment, X is preferably S. In another aspect of the above embodiment, X is preferably Se. In another aspect of the above embodiment, X is preferably Te.

[0065] In one aspect of the above embodiment, one or both of R1 and R2 are preferably hydrogen. In one aspect of the above embodiment, one or both of R1 and R2 are preferably methyl. In one aspect of the above embodiment, one or both of R1 and R2 are preferably ethyl. In one aspect of the above embodiment, one or both of R1 and R2 are preferably n-propyl. In one aspect of the above embodiment, one or both of R1 and R2 are preferably iso-propyl. In one aspect of the above embodiment, one or both of R1 and R2 are preferably n-butyl. In one aspect of the above embodiment, one or both of R1 and R2 are preferably iso-butyl. In one aspect of the above embodiment, one or both of R1 and R2 are preferably tert-butyl.

[0066] As will be apparent to one skilled in the art, when delivering the chalcogenide precursor, factors such as the pulse time of the chalcogenide precursor, the vapor pressure of the chalcogenide precursor, and the carrier flow rate of the chalcogenide precursor to determine the arrival rate of the chalcogenide precursor molecules into the chamber, as well as the total dose of the chalcogenide precursor molecules into the chamber can be adjusted to balance these factors. For example, increasing the vapor pressure by a factor of two while shortening the pulse time by a factor of two will keep the dose of the chalcogenide precursor constant while still changing the arrival rate of the chalcogenide precursor molecules. The co-variation of these three variables determines the total dose of the chalcogenide precursor into the chamber, the flux rate of the chalcogenide precursor molecules into the chamber, the time each chalcogenide precursor molecule is allowed to evaporate in the chalcogenide precursor ampoule, and any carrier gas turbulence in the chalcogenide precursor ampoule.

[0067] In one embodiment, the pulse time of the chalcogenide precursor is about 0.5 seconds to about 25 seconds. In one embodiment, the pulse time of the chalcogenide precursor is about 1 second to about 15 seconds. In one embodiment, the pulse time of the chalcogenide precursor is about 1 second. In one embodiment, the pulse time of the chalcogenide precursor is about 5 seconds. In one embodiment, the pulse time of the chalcogenide precursor is about 10 seconds. In one embodiment, the pulse time of the chalcogenide precursor is about 15 seconds.

[0068] The vapor pressure of the precursor is controlled by selecting the chalcogenide precursor molecule and, if the precursor is a liquid, the temperature of the ampoule. In one embodiment, the vapor pressure of the chalcogenide precursor is about 0.3 Torr to about 15,000 Torr. In one embodiment, the vapor pressure of the chalcogenide precursor is about 2 Torr. In one embodiment, the vapor pressure of the chalcogenide precursor is about 10 Torr. In one embodiment, the vapor pressure of the chalcogenide precursor is about 30 Torr. In one embodiment, the vapor pressure of the chalcogenide precursor is about 90 Torr. In one embodiment, the vapor pressure of the chalcogenide precursor is about 200 Torr. In one embodiment, the chalcogenide precursor is a gas delivered to the chamber (by definition, a gas has a vapor pressure of ≧760 Torr), such as H2S, which has a vapor pressure of about 13,000 Torr at 70° C.

[0069] In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 0 sccm (vapor draw) to about 3000 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 5 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 50 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 100 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 250 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 500 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 750 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 1000 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 1250 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 1500 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 1750 sccm. In one embodiment, the carrier gas flow rate of the chalcogenide precursor is about 2000 sccm.

[0070] Preferred Precursor Population The ALD processes of the disclosed and claimed subject matter can utilize any precursor collection combining MoO2Cl2 and / or MoO2Br2 with one or more of the chalcogenide precursors listed above, as follows:

[0071] In one embodiment, the precursor collection includes MoO2Cl2 and iBu2S. In one embodiment, the precursor collection includes MoO2Br2 and iBu2S.

[0072] In one embodiment, the precursor population includes MoO2Cl2 and iPr2S. In one embodiment, the precursor population includes MoO2Br2 and iPr2S.

[0073] In one embodiment, the precursor population includes MoO2Cl2 and iPr2Se. In one embodiment, the precursor population includes MoO2Br2 and iPr2Se.

[0074] In one embodiment, the precursor collection includes MoO2Cl2 and Et2S2. In one embodiment, the precursor collection includes MoO2Br2 and Et2S2.

[0075] In one embodiment, the precursor collection includes MoO2Cl2 and Et2Se. In one embodiment, the precursor collection includes MoO2Br2 and Et2Se.

[0076] In one embodiment, the precursor collection includes MoO2Cl2 and tBuSH. In one embodiment, the precursor collection includes MoO2Br2 and tBuSH.

[0077] In one embodiment, the precursor collection includes MoO2Cl2 and H2Se. In one embodiment, the precursor collection includes MoO2Br2 and H2Se.

[0078] In one embodiment, the precursor collection includes MoO2Cl2 and H2S. In one embodiment, the precursor collection includes MoO2Br2 and H2S.

[0079] In one embodiment, the precursor collection includes MoO2Cl2 and H2Te. In one embodiment, the precursor collection includes MoO2Br2 and H2Te.

[0080] In one embodiment, the precursor collection includes MoO2Cl2 and Et2Te. In one embodiment, the precursor collection includes MoO2Br2 and Et2Te.

[0081] In one embodiment, the precursor collection includes MoO2Cl2 and iPr2Te. In one embodiment, the precursor collection includes MoO2Br2 and iPr2Te.

[0082] Optional Chalcogenide Precursor Purge Step As noted above, step (iv) of the disclosed and claimed methods optionally includes purging any unreacted chalcogenide precursor with an inert gas. Purging with an inert gas removes any residual chalcogenide precursor from the process reactor. In one embodiment, the purge gas comprises argon. In another embodiment, the purge gas comprises nitrogen. As will be apparent to one of ordinary skill in the art, in many, if not most, instances, the disclosed and claimed processes will include a step of purging unreacted chalcogenide precursor.

[0083] In one embodiment, for example, the purge time of any chalcogenide precursor is about 4 seconds to about 90 seconds. In one embodiment, for example, the purge time of any chalcogenide precursor is about 15 seconds to about 60 seconds. In another embodiment, for example, the purge time of any chalcogenide precursor is about 30 seconds. In another embodiment, for example, the purge time of any chalcogenide precursor is about 60 seconds. In another embodiment, for example, the purge time of any chalcogenide precursor is about 90 seconds.

[0084] Additional Gas and / or Plasma Treatments As noted above, step (v) of the disclosed and claimed method includes treating the substrate with H2S gas and / or H2S plasma to remove residual oxygen from the film formed during the previous step.

[0085] In one embodiment, the use of plasma constitutes a direct plasma generated process, where the plasma is generated directly within the reactor, while in another embodiment, the use of plasma constitutes a remote plasma generated process, where the plasma is generated outside the reactor and fed into the reactor.

[0086] Operating conditions As described above, the disclosed and claimed molybdenum deposition process can be efficiently carried out under extremely favorable ALD conditions to provide highly conformal Mo-containing films.

[0087] temperature In one embodiment, a substrate (e.g., aluminum oxide (Al2O3), aluminum nitride (AlN), silicon oxide (SiO2), silicon oxynitride, silicon nitride (Si3N4), zirconium oxide (ZrO2), and hafnium oxide (HfO2)) is heated on a heater stage in a reactor. The heater stage is exposed to a selected precursor that is initially set to allow the complex to be chemisorbed onto the surface of the substrate. In one embodiment, the substrate temperature is about 100°C to about 650°C. In one embodiment, the substrate temperature is about 200°C to about 650°C. In a further aspect of this embodiment, the substrate temperature is about 250°C to about 600°C. In a further aspect of this embodiment, the substrate temperature is about 300°C to about 550°C. In a further aspect of this embodiment, the substrate temperature is about 450°C to about 525°C.

[0088] In a further aspect of this embodiment, the substrate temperature is about 150° C. In a further aspect of this embodiment, the substrate temperature is about 200° C. In a further aspect of this embodiment, the substrate temperature is about 250° C. In a further aspect of this embodiment, the substrate temperature is about 300° C. In a further aspect of this embodiment, the substrate temperature is about 350° C. In a further aspect of this embodiment, the substrate temperature is about 400° C. In a further aspect of this embodiment, the substrate temperature is about 425° C. In a further aspect of this embodiment, the substrate temperature is about 450° C. In a further aspect of this embodiment, the substrate temperature is about 475° C. In a further aspect of this embodiment, the substrate temperature is about 500° C. In a further aspect of this embodiment, the substrate temperature is about 525° C. In a further aspect of this embodiment, the substrate temperature is about 550° C. In a further aspect of this embodiment, the substrate temperature is about 600° C. In a further aspect of this embodiment, the substrate temperature is about 625° C. In a further aspect of this embodiment, the substrate temperature is about 650° C.

[0089] In one embodiment, the substrate temperature is set to be below the decomposition temperature of each of the precursors utilized in the process. In one embodiment, the substrate temperature is set to be close to, at, or above the decomposition temperature of only one of the precursors utilized in the process if the process still acts as an ALD process (negligible CVD component). In one embodiment, the substrate temperature is set to be close to, at, or above the decomposition temperature of only two or more of the precursors utilized in the process if the process still acts as an ALD process (negligible CVD component). In one embodiment, the substrate temperature is set to be close to, at, or above the decomposition temperature of each of the precursors utilized in the process if the process still acts as an ALD process (negligible CVD component).

[0090] pressure In another embodiment, the reactor pressure for deposition according to the disclosed and claimed subject matter is from about 0.1 to about 100 Torr. In another embodiment, the reactor pressure for deposition according to the disclosed and claimed processes is from about 2 Torr to about 10 Torr.

[0091] In another embodiment, the reactor pressure for deposition according to the disclosed and claimed processes is ≦about 50 Torr. In another embodiment, the reactor pressure for deposition according to the disclosed and claimed processes is ≦about 40 Torr. In another embodiment, the reactor pressure for deposition according to the disclosed and claimed processes is ≦about 30 Torr. In a further aspect of this embodiment, the reactor pressure is ≦about 20 Torr. In a further aspect of this embodiment, the reactor pressure is ≦about 10 Torr. In a further aspect of this embodiment, the reactor pressure is ≦about 5 Torr.

[0092] Process cycle and sequence In the above embodiment, as well as other embodiments described herein, the recited steps (e.g., (i)-(iv) or (i)-(v)) define one cycle of the method. It is noted that the cycles can be repeated until the desired film thickness is obtained. In one embodiment, the ALD method includes about 5 to about 2000 cycles. In one embodiment, the ALD method includes about 20 to about 1000 cycles. In one embodiment, the ALD method includes about 50 to about 500 cycles. In one embodiment, the ALD method includes about 100 to about 300 cycles. In one embodiment, the ALD method includes about 5 cycles. In one embodiment, the ALD method includes about 10 cycles. In one embodiment, the ALD method includes about 15 cycles. In one embodiment, the ALD method includes about 20 cycles. In one embodiment, the ALD method includes about 25 cycles. In one embodiment, the ALD method includes about 50 cycles. In one embodiment, the ALD method includes about 100 cycles. In one embodiment, the ALD method includes about 150 cycles. In one embodiment, the ALD method includes about 200 cycles. In one embodiment, the ALD method includes about 250 cycles. In one embodiment, the ALD method includes about 300 cycles. In one embodiment, the ALD method includes about 350 cycles. In one embodiment, the ALD method includes about 400 cycles. In one embodiment, the ALD method includes about 450 cycles. In one embodiment, the ALD method includes about 500 cycles. In one embodiment, the ALD method includes about 550 cycles. In one embodiment, the ALD method includes about 600 cycles. In one embodiment, the ALD method includes about 650 cycles. In one embodiment, the ALD method includes about 700 cycles. In one embodiment, the ALD method includes about 750 cycles. In one embodiment, the ALD method includes about 1000 cycles. In one embodiment, the ALD method includes about 1250 cycles. In one embodiment, the ALD method includes about 1500 cycles. In one embodiment, the ALD method includes about 1750 cycles. In one embodiment, the ALD method includes about 2000 cycles. In one embodiment, the ALD process includes about 2500 cycles.

[0093] In one embodiment, the ALD method allows for fin-less TMD growth. Fin-less TMD growth (e.g., for a superconducting channel layer in a device, such as a transistor) is performed by limiting the growth cycles to the onset of fin nucleation. These growth cycles are about 400 cycles for MoO2Cl2+H2S. As such, in one embodiment, the ALD method includes 50 cycles. In one embodiment, the ALD method includes about 100 cycles. In one embodiment, the ALD method includes about 150 cycles. In one embodiment, the ALD method includes about 200 cycles. In one embodiment, the ALD method includes about 250 cycles. In one embodiment, the ALD method includes about 300 cycles. In one embodiment, the ALD method includes the maximum number of cycles if fin nucleation has not yet occurred for that particular precursor combination and chamber hardware.

[0094] In the embodiments described herein, the steps of the method may be performed in various orders, sequentially or simultaneously (e.g., between at least a portion of another step), and in any combination thereof. In addition, each step of supplying one or more of MoO2Cl2 and MoO2Br2, and one or more of a nitrogen source, may be performed by varying the time for supplying them to vary the film composition. For example, one embodiment performs the steps in an ALD cycle in the following order: (iii), (iv), (i), (ii) repeated x times, optionally followed by step (iii).

[0095] Exemplary Process film The disclosed and claimed subject matter includes membranes prepared by the methods described herein.

[0096] In one embodiment, the films formed by the methods described herein have trenches, vias, or other topographical features with an aspect ratio of about 1 to about 750. In a further aspect of this embodiment, the aspect ratio is about 5 to about 500. In a further aspect of this embodiment, the aspect ratio is about 10 to about 350. In a further aspect of this embodiment, the aspect ratio is about 15 to about 300. In a further aspect of this embodiment, the aspect ratio is about 1 to about 20. In a further aspect of this embodiment, the aspect ratio is about 15 to about 200. In a further aspect of this embodiment, the aspect ratio is greater than about 5. In a further aspect of this embodiment, the aspect ratio is greater than about 10. In a further aspect of this embodiment, the aspect ratio is greater than about 20. In a further aspect of this embodiment, the aspect ratio is greater than about 30. In a further aspect of this embodiment, the aspect ratio is greater than about 50. In a further aspect of this embodiment, the aspect ratio is greater than about 70. In further aspects of this embodiment, the aspect ratio is greater than about 100. In further aspects of this embodiment, the aspect ratio is greater than about 150. In further aspects of this embodiment, the aspect ratio is greater than about 200. In further aspects of this embodiment, the aspect ratio is greater than about 300. In further aspects of this embodiment, the aspect ratio is greater than about 400. In further aspects of this embodiment, the aspect ratio is greater than about 500.

[0097] In another embodiment, the membrane formed by the method described herein has a mobility of about 1 to about 350. In a further aspect of this embodiment, the membrane has a mobility of about 5 to about 300. In a further aspect of this embodiment, the membrane has a mobility of about 10 to about 250. In a further aspect of this embodiment, the membrane has a mobility of about 20 to about 220. In a further aspect of this embodiment, the membrane has a mobility of about 30 to about 200. In a further aspect of this embodiment, the membrane has a mobility of about 40 to about 180. In a further aspect of this embodiment, the membrane has a mobility of about 15. In a further aspect of this embodiment, the membrane has a mobility of about 30. In a further aspect of this embodiment, the membrane has a mobility of about 50. In a further aspect of this embodiment, the membrane has a mobility of about 80. In a further aspect of this embodiment, the membrane has a mobility of about 100. In a further aspect of this embodiment, the membrane has a mobility of about 125. In a further aspect of this embodiment, the membrane has a mobility of about 150. In a further aspect of this embodiment, the membrane has a mobility of about 175. In a further aspect of this embodiment, the membrane has a mobility of about 200. In a further aspect of this embodiment, the membrane has a mobility of about 250. In a further aspect of this embodiment, the membrane has a mobility of about 300.

[0098] Reference is now made to more specific embodiments of the present disclosure, and test results indicative of such embodiments. The examples are provided below to more fully illustrate the disclosed subject matter, and should not be construed as limiting the disclosed subject matter in any way.

[0099] As will be apparent to those skilled in the art, various modifications and variations can be made to the disclosed subject matter and specific examples provided herein without departing from the spirit or scope of the disclosed subject matter. Thus, the disclosed subject matter, including the description provided by the examples below, is intended to cover modifications and variations of the disclosed subject matter that fall within the scope of any claims and their equivalents.

[0100] Materials and Methods All materials, including MoO2Cl2, were purchased from Versum Materials, and all films were deposited in an Intermolecular A30 chamber. EXAMPLES

[0101] Example 1 In Example 1, ALD 2D TMD growth of MoSe2 was achieved using MoO2Cl2+iPr2Se with MoO2Cl2 pulse length saturation at 450° C. substrate temperature, where the MoO2Cl2 carrier flow rate was set to 50 sccm, the MoO2Cl2 pulse pressure was set to 4 Torr, the MoO2Cl2 purge length was set to 50 s, the iPr2Se pulse time was set to 10 s, the iPr2Se ampoule temperature was set to 29° C., the iPr2Se carrier flow rate was set to 100 sccm, the iPr2Se pulse pressure was set to 5 Torr, the iPr2Se purge length was set to 50 s, and each deposition was performed for 100 ALD cycles. As shown in FIG. 1, the deposited MoSe2 thickness is shown as a function of MoO2Cl2 flux with saturation over an order of magnitude. Note that the XRF Se / Mo ratio is the ratio of raw counts, and a raw count ratio of about 0.6 translates to an XRF Se / Mo ratio of about 2.

[0102] The deposition process exhibits a flat deposition rate over the entire temperature range of the ALD deposition window. As shown in Figure 2, the wafer temperature curves indicate that ALD MoO2Cl2+iPr2Se has an ALD window that extends from about 450°C-475°C to substrate temperatures of at least about 600°C, at a nearly constant temperature, as measured by Mo XRF kCPS. In this case, the MoO2Cl2 ampoule temperature was set to 65°C, the MoO2Cl2 precursor pulse length was set to 5s, the MoO2Cl2 carrier flow rate was set to 50sccm, the MoO2Cl2 pulse pressure was set to 4Torr, the MoO2Cl2 purge length was set to 50s, the iPr2Se pulse time was set to 10s, the iPr2Se ampoule temperature was set to 29°C, the iPr2Se carrier flow rate was set to 100sccm, the iPr2Se pulse pressure was set to 5Torr, the iPr2Se purge length was set to 50s, and each deposition was performed for 100 ALD cycles. Note again that the XRF Se / Mo ratio is the ratio of raw counts, and a raw count ratio of about 0.6 translates to an XRF Se / Mo ratio of about 2.

[0103] The ALD process also exhibits self-limiting layer synthesis behavior in its growth curves. In Figure 3, the ALD deposition of MoO2Cl2+iPr2Se displays self-limiting layer synthesis behavior from about 475 °C to about 600 °C and asymptotically reaches similar thicknesses as measured by Mo XRF kCPS. The MoO2Cl2+iPr2Se growth curve shows thickness saturation at about 500 cycles.

[0104] As shown in Figure 4, Raman spectroscopy indicates that the MoSe2 films are all good quality 2D 2H phase MoSe2 films. In addition, as shown in Figure 5, analysis of the Raman FWHM versus deposition temperature across the illustrated growth curves indicates that the films have narrow FWHM and are stoichiometric or near stoichiometric as measured by XPS. In Figure 5, the left image shows the A 1gThe FWHM versus ALD cycles is shown, and the image on the right shows the XPS Se / Mo ratio versus cycle number at two temperatures.

[0105] Example 2 In Example 2, ALD 2D TMD growth of MoS2 was accomplished using ALD MoO2Cl2+Et2S2 (diethyl disulfide or "DEDS") Figures 6 and 7 show the saturation curves of MoO2Cl2 and Et2S2 measured at 600 °C for this example. Specifically, Figure 6 shows DEDS saturation curves (at a substrate temperature of 600°C with (a) a 5 second MoO2Cl2 pulse time, a 50 sccm MoO2Cl2Ar gas carrier flow rate, (b) a 40 second MoO2Cl2 purge time, (c) a 50 sccm MoO2Cl2Ar gas carrier flow rate, (d) a 40 second MoO2Cl2 purge time, (e) a 100 sccm DEDS Ar gas carrier flow rate, and (f) a 60 second DEDS purge time) showing saturation of MoS2 at about a 3 second DEDS pulse length using MoO2Cl2+Et2S2 in an embodiment (Example 2) of the disclosed and claimed subject matter. Figure 7 shows the MoO2Cl2 saturation curve corresponding to Example 2 showing saturation at about a 3 second MoO2Cl2 pulse length.

[0106] The ALD temperature curves shown in FIG. 8 indicate that the ALD window of ALD MoO2Cl2+Et2S2 from Example 2 is from about 450° C. to at least 625° C. substrate temperature, as measured by Mo XRF kCPS.

[0107] FIG. 9 shows that the ALD MoO2Cl2+Et2S2 growth curve exhibits soft saturation behavior (i.e., sublinear thickness vs. ALD cycle number instead of asymptotic curve vs. ALD cycle number), suggesting that the etch component is not fully balanced with the deposition component up to 500 cycles. This deposition behavior allows for better thickness targeting and better thickness uniformity at right cycle counts compared to linear or superlinear curves (non-self-limiting layer synthesis-like behavior). As shown in FIG. 10, this deposition behavior results in more uniform monolayers at larger thicknesses. FIG. 10 plots Raman A1g and E2g FWHM vs. ALD cycle number for the sample of FIG. 9. This analysis shows that at 300-500 cycles, the Raman reaches an optimally narrow FWHM for the saturated MoO2Cl2+DEDS process. This analysis further includes full Raman spectra for films deposited at 50 and 500 cycles.

[0108] In growing high quality 2D materials, it is desirable to initiate growth at well-isolated nucleation sites and grow laterally from these sites until they coalesce with the surrounding islands to form a continuous 2D layer. It is undesirable to have secondary islands that start growing on top of uncoalesced islands. Figure 11 (SEM) and Figure 12 (TEM) show the growth of small new islands on top of the coalesced layer after 300 ALD cycles, and the emergence of fin growth after 500 ALD cycles. Figure 12 is a TEM image of 100 ALD cycles of MoS2, showing fin-free MoS2 over the entire area where TEM analysis is performed.

[0109] Example 3 Additional exemplary formulations are listed in Table 1, which lists relevant materials and applicable ALD conditions. Abbreviations: Chalcogenides ("CGD").

[0110] [Table 1]

[0111] While the disclosed and claimed subject matter has been described and illustrated with a certain degree of particularity, it will be understood that the disclosure is made by way of example only, and that numerous changes in the conditions and sequence of steps can be made by one skilled in the art without departing from the spirit and scope of the disclosed and claimed subject matter.

Claims

1. 1. A method for depositing a Mo-containing film, comprising: (i) The substrate is heated to MoO in the deposition reactor. ２ Cl ２ and MoO ２ Br ２ contacting the mixture with one or more of the following vapors: (ii) any unreacted MoO ２ Cl ２ or MoO ２ Br ２ purged with inert gas, (iii) treating the substrate in the deposition reactor with a compound of formula (i)R １ XR ２ or formula (ii) R １ XXR ２ with one or more chalcogenide precursors of where: X=S, Se or Te, and R １ and R ２ are each independently hydrogen, unsubstituted linear C １ -C ６ Alkyl groups, linear C substituted with one or more halogens １ -C ６ Linear C substituted with alkyl or amino groups １ -C ６ Alkyl group, unsubstituted branched C ３ -C ６ alkyl group, branched C substituted with one or more halogens ３ -C ６ Branch C substituted with alkyl group or amino group ３ -C ６ Alkyl groups, unsubstituted amines, substituted amines, and —Si(CH ３ ) ３ It is one of the (iv) optionally purging any unreacted chalcogenide precursor with an inert gas; and (v) optionally, treating said substrate with H ２ S gas and H ２ S plasma, 1. A method for depositing a Mo-containing film, comprising:

2. The substrate was heated to 1000°C in a deposition reactor. ２ Cl ２ and MoO ２ Br ２ The step (i) of contacting the MoO ２ Cl ２ and MoO ２ Br ２ The method of claim 1, comprising pulsing one or more of the vapors for about 0.1 seconds to about 25 seconds.

3. The substrate was heated to 1000°C in a deposition reactor. ２ Cl ２ and MoO ２ Br ２ 3. The method of claim 1 or 2, wherein step (i) of contacting with one or more of the steam comprises pulsing at an ampoule temperature of about 55°C to about 300°C.

4. The substrate was heated to 1000°C in a deposition reactor. ２ Cl ２ and MoO ２ Br ２ 3. The method of claim 1, wherein the step (i) of contacting with one or more of the vapors comprises pulsing a gas flow rate of from about 5 sccm to about 3000 sccm.

5. The one or more chalcogenide precursors are represented by the formula (i) R １ XR ２ where X=S, Se or Te and R １ and R ２ The method of claim 1 or 2, wherein each is independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl.

6. The one or more chalcogenide precursors are represented by the formula (ii) R １ XXR ２ where X=S, Se or Te and R １ and R ２ The method of claim 1 or 2, wherein each is independently one of hydrogen, methyl, ethyl, n-propyl, iso-propyl, n-butyl, sec-butyl, iso-butyl, and tert-butyl.

7. 3. The method of claim 1 or 2, wherein X is S.

8. 3. The method of claim 1 or 2, wherein X is Se.

9. 3. The method of claim 1 or 2, wherein X is Te.

10. The one or more chalcogenide precursors may comprise iBu ２ 3. The method of claim 1 or 2, comprising one or more of S, iPr2S, iPr2Se, Et2S2, Et2Se, tBuSH, H2Se, H2S, H2Te, Et2Te and iPr2Te.

11. 3. The method of claim 1, wherein the step (iii) of contacting the substrate in the deposition reactor with one or more chalcogenide precursors comprises pulsing the precursors for about 0.5 seconds to about 25 seconds.

12. 3. The method of claim 1, wherein step (iii) of contacting the substrate in the deposition reactor with one or more chalcogenide precursors comprises pulsing the precursors at a vapor pressure of about 0.3 Torr to about 15,000 Torr.

13. 3. The method of claim 1, wherein step (iii) of contacting the substrate in the deposition reactor with one or more chalcogenide precursors comprises pulsing the precursors at a carrier gas flow rate of about 0 sccm to about 3000 sccm.

14. The substrate is H ２ S gas and H ２ The step (v) of treating with one or more of H ２ S plasma treatment, ２ 3. The method of claim 1, wherein the S plasma is generated directly in the reactor.

15. The substrate is H ２ S gas and H ２ The step (v) of treating with one or more of H ２ S plasma treatment, ２ 3. The method according to claim 1, wherein the S plasma is generated outside the reactor and then fed into the reactor.

16. The substrate is made of aluminum oxide (Al ２ O ３ ), aluminum nitride (AIN), silicon oxide (SiO2), silicon oxynitride, silicon nitride (Si3N4), zirconium oxide (ZrO2), and hafnium oxide (HfO2).

17. The method of claim 1 or 2, wherein the reactor pressure is from about 0.1 to about 100 Torr.

18. A molybdenum-containing film deposited by the process of claim 1 or 2.

19. The substrate is MoO ２ Cl ２ and MoO ２ Br ２ wherein step (i) of contacting the substrate with one or more of MoO ２ Cl ２ 3. The method of claim 1 or 2, comprising contacting the

20. The substrate is MoO ２ Cl ２ and MoO ２ Br ２ wherein step (i) of contacting the substrate with one or more of MoO ２ Br ２ 3. The method of claim 1 or 2, comprising contacting the

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