Molybdenum(0) Precursor for Deposition of Molybdenum Films

Abstract

Molybdenum(0) and coordination complexes are described. Methods of depositing molybdenum-containing films on substrates are described. The substrates are exposed to molybdenum precursors and reactants to form molybdenum-containing films (e.g., elemental molybdenum, molybdenum oxide, molybdenum carbide, molybdenum silicide, molybdenum disulfide, molybdenum nitride). Exposure can be sequential or simultaneous.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to molybdenum precursors and methods for depositing molybdenum-containing films. More particularly, embodiments of the present disclosure are directed to molybdenum(0) complexes containing 2n electron donor neutral mono-, bi-, and tridentate ligands, and methods of using the same.

Background Art

[0002] The semiconductor processing industry continues to strive for higher production yields while improving the uniformity of layers deposited on substrates having larger surface areas. The combination of these same elements with new materials also results in an increase in the integration density of circuits per unit area of the substrate. As the integration density of circuits increases, the need for uniformity and process control with respect to the thickness of the layers is increasing. As a result, various techniques have been developed for depositing layers on substrates in a cost-effective manner while maintaining control over the properties of the layers.

[0003] Chemical vapor deposition (CVD) is one of the most common deposition processes used to deposit layers on substrates. CVD is a flux-dependent deposition technique, which requires precise control of the substrate temperature and the precursors introduced into the processing chamber to produce a desired layer of uniform thickness. These requirements become more important as the substrate size increases, resulting in the need for more complex chamber designs and gas flow techniques to maintain appropriate uniformity.

[0004] A variant of CVD that exhibits excellent step coverage is cyclic deposition or atomic layer deposition (ALD). Cyclic deposition is based on atomic layer epitaxy (ALE) and uses chemisorption techniques to supply precursor molecules to the substrate surface in successive cycles. The cycles expose the substrate surface to a first precursor, a purge gas, a second precursor, and a purge gas. The first precursor and the second precursor react to form a product compound as a film on the substrate surface. This cycle is repeated to form the layer to the desired thickness.

[0005] As the complexity of advanced microelectronic devices progresses, stringent requirements are imposed on the deposition techniques currently in use. Unfortunately, the number of available and viable chemical precursors with the essential properties of robust thermal stability, high reactivity, and a vapor pressure suitable for film growth is limited. Furthermore, precursors that often meet these requirements still lack long-term stability and lead to the formation of thin films containing high concentrations of contaminants that are often harmful to the intended film applications, such as oxygen, nitrogen, and / or halides.

[0006] Molybdenum films and molybdenum-based films have attractive material and conductive properties. These films have been proposed and tested for various applications from the front-end to the back-end of semiconductor and microelectronic devices. The processing of molybdenum precursors often involves the use of halogen-based and carbonyl-based substituents. These ligands provide sufficient stability at the expense of reduced reactivity and increased process temperature. Therefore, there is a need in the art for molybdenum precursors that react to form molybdenum metal and molybdenum-based films and do not contain halogen groups. SUMMARY OF THE INVENTION

[0007] One or more embodiments of the present disclosure are directed to metal coordination complexes. In one or more embodiments, the metal coordination complex includes molybdenum(0) and has the structure of Formula (I), Formula (II), or Formula (III): TIFF0007714679000001.tif48170[wherein L is one or more of a 2n-electron donor neutral monodentate ligand, a 2n-electron donor neutral bidentate ligand, and a 2n-electron donor neutral tridentate ligand], and the metal coordination complex is substantially free of halogen and substantially free of Mo—O bonds.

[0008] One or more embodiments of the present disclosure are directed to a method of depositing a film. In one or more embodiments, the method of depositing a film includes exposing a substrate to a molybdenum(0) precursor; and exposing the substrate to a reactant to form a substantially halogen-free molybdenum-containing film on the substrate surface.

[0009] Further embodiments of the present disclosure are directed to a method of depositing a film. In one or more embodiments, the method of depositing a film includes forming a molybdenum-containing film in a process cycle that includes continuous exposure of a molybdenum(0) precursor, a purge gas, a reactant, and the substrate to the purge gas.

[0010] To gain a more detailed understanding of the above features of the present disclosure, a more detailed description of the present disclosure, briefly summarized above, can be obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings show only typical embodiments of the present disclosure, and thus the present disclosure may admit other equally effective embodiments and should not be considered as limiting its scope.

Brief Description of the Drawings

[0011]

Figure 1

Modes for Carrying Out the Invention

[0012] Before describing some exemplary embodiments of the present invention, it should be understood that the present invention is not limited to the details of the structures or process steps described in the following description. The present invention is capable of other embodiments and can be practiced or carried out in various ways.

[0013] Embodiments of the present disclosure provide a precursor and a process for depositing a molybdenum-containing film. These metal coordination complexes of one or more embodiments substantially do not contain halogen and molybdenum-oxygen bonds. The ligands can be 2n-electron donor neutral monodentate, bidentate, and tridentate ligands. The bonds between the ligands provide further stability under ALD and CVD conditions. The processes of various embodiments provide molybdenum films using vapor deposition techniques such as atomic layer deposition (ALD) or chemical vapor deposition (CVD). The molybdenum precursor of one or more embodiments is volatile and thermally stable and is thus suitable for vapor deposition.

[0014] In one or more embodiments, the molybdenum precursor does not contain halogen. In other embodiments, the molybdenum precursor does not contain molybdenum-oxygen (Mo-O) bonds. In one or more embodiments, the molybdenum precursor does not contain halogen and does not contain molybdenum-oxygen (Mo-O) bonds.

[0015] As used herein, the term "substantially does not contain" means that there is less than about 5% halogen, including less than about 4%, less than about 3%, less than about 2%, less than about 1%, and less than about 0.5% on an atomic basis in the molybdenum-containing film. In some embodiments, the molybdenum-containing film substantially does not contain molybdenum-oxygen (Mo-O) bonds, and there are less than about 10%, less than about 9%, less than about 8%, less than about 7%, less than about 6%, less than about 5% molybdenum-oxygen bonds on an atomic basis in the molybdenum-containing film, including less than about 4%, less than about 3%, less than about 2%, less than about 1%, and less than about 0.5%.

[0016] As used herein, the "substrate" refers to any substrate or the surface of a material formed on a substrate on which film processing is performed during the manufacturing process. For example, as the substrate surface on which processing can be performed, depending on the application, materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal oxides, metal nitrides, metal alloys, and other conductive materials can be mentioned. The substrate includes, but is not limited to, semiconductor wafers. The substrate may be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to the direct film processing on the surface of the substrate itself, in the present invention, any of the disclosed film processing steps can also be performed on the underlying layer formed on the substrate as disclosed in more detail below, and the term "substrate surface" is intended to include such an underlying layer as the context indicates. Thus, for example, when a film / layer or a partial film / layer is deposited on the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0017] According to one or more embodiments, the method uses an atomic layer deposition (ALD) process. In such embodiments, the substrate surface is continuously or substantially continuously exposed to a precursor (or reactive gas). As used throughout this specification, "substantially continuous" means that there may be some overlap, but most of the precursor exposure period does not overlap with the exposure to the co-reactant.

[0018] As used in this specification and the appended claims, terms such as "precursor", "reactant", "reactive gas", etc. are used interchangeably to refer to any gaseous species that can react with the substrate surface.

[0019] As used herein, "atomic layer deposition" or "cyclic deposition" refers to the sequential exposure to two or more reactive compounds to deposit a layer of material on a substrate surface. As used in this specification and the appended claims, terms such as "reactive compound", "reactive gas", "reactive species", "precursor", "process gas", etc. are used interchangeably to mean a substance having a species capable of reacting with the substrate surface or a material on the substrate surface in a surface reaction (e.g., chemisorption, oxidation, reduction). The substrate or a portion of the substrate is sequentially exposed to two or more reactive compounds introduced into the reaction zone of the processing chamber. In a time-domain ALD process, the exposure to each reactive compound is separated by a time delay to allow each compound to adhere to and / or react with the substrate surface. In a spatial ALD process, different portions of the substrate surface or materials on the substrate surface are exposed to two or more reactive compounds simultaneously such that any given point on the substrate is not substantially exposed to more than one reactive compound at the same time. As used in this specification and the appended claims, the term "substantially" used in this context means that, as would be understood by one of ordinary skill in the art, although a small portion of the substrate may potentially be exposed to multiple reactive gases simultaneously by diffusion, such simultaneous exposure is not intended.

[0020] In one aspect of a time-domain ALD process, a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, followed by a first time delay. Next, a second precursor or compound B is pulsed into the reaction zone, followed by a second delay. During each time delay, a purge gas, such as argon, is introduced into the processing chamber to purge the reaction zone or otherwise remove any residual reactive compounds or by-products from the reaction zone. Alternatively, the purge gas may be continuously flowed throughout the deposition process such that only the purge gas flows during the time delay between pulses of the reactive compounds. Alternatively, the reactive compounds are pulsed until the desired film or film thickness is formed on the substrate surface. In any scenario, the ALD process that pulses compound A, the purge gas, compound B, and the purge gas is one cycle. The cycle can start with either compound A or compound B and can continue in each sequence of the cycle until the desired thickness of the film is achieved. In some embodiments, there may be two reactants A and B that are pulsed and purged alternately. In other embodiments, there may be three or more reactants A, B, and C that are pulsed and purged alternately.

[0021] In an aspect of a spatial ALD process, a first reactive gas and a second reactive gas (e.g., hydrogen radicals) are supplied to the reaction zone simultaneously but are separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas supply device such that any given point on the substrate is exposed to the first reactive gas and the second reactive gas.

[0022] Without being bound by theory, it is believed that the presence of halogen in the structure of a molybdenum (Mo) precursor can cause problems because halogen contamination can affect the performance of the device and thus additional removal procedures may be required.

[0023] Molybdenum (Mo) can be grown by atomic layer deposition or chemical vapor deposition for many applications. One or more embodiments of the present disclosure advantageously provide a process of atomic layer deposition or chemical vapor deposition for forming a molybdenum-containing film. As used herein and in the appended claims, the term "molybdenum-containing film" includes molybdenum atoms and has about 1 atomic % or more of molybdenum, about 2 atomic % or more of molybdenum, about 3 atomic % or more of molybdenum, about 4 atomic % or more of molybdenum, about 5 atomic % or more of molybdenum, about 10 atomic % or more of molybdenum, about 15 atomic % or more of molybdenum, about 20 atomic % or more of molybdenum, about 25 atomic % or more of molybdenum, about 30 atomic % or more of molybdenum, about 35 atomic % or more of molybdenum, about 40 atomic % or more of molybdenum, about 45 atomic % or more of molybdenum, about 50 atomic % or more of molybdenum, about 60 atomic % or more of molybdenum, about 70 atomic % or more of molybdenum, about 80 atomic % or more of molybdenum, about 90 atomic % or more of molybdenum, or about 95 atomic % or more of molybdenum. In some embodiments, the molybdenum-containing film includes one or more of molybdenum metal (elemental molybdenum), molybdenum oxide (MoO x ), molybdenum carbide (MoC x ), molybdenum silicide (MoSi x ), molybdenum sulfide (MoS x ), or molybdenum nitride (MoN x ).

[0024] One of ordinary skill in the art will recognize that the use of a chemical formula such as MoSi x does not imply a specific stoichiometric relationship between the elements, but merely indicates the identity of the major components of the film. For example, MoSi x refers to a film having molybdenum atoms and silicon atoms as the major components. In some embodiments, the major composition of a given film (i.e., the sum of the atomic percentages of the given atoms) is about 95%, 98%, 99%, or 99.5% or more of the film on an atomic basis.

[0025] Referring to FIG. 1, one or more embodiments of the present disclosure are directed to a method 100 of depositing a film. The method shown in FIG. 1 represents an atomic layer deposition (ALD) process of continuously exposing a substrate or a substrate surface to a reactive gas in a manner that prevents or minimizes the gas-phase reaction of the reactive gas. In some embodiments, the method includes a chemical vapor deposition (CVD) process in which the reactive gas is mixed in a processing chamber to enable the gas-phase reaction of the reactive gas and the deposition of a thin film.

[0026] In some embodiments, method 100 optionally includes a pretreatment operation 105. The pretreatment can be any suitable pretreatment known to those skilled in the art. Suitable pretreatments include, but are not limited to, preheating, cleaning, dipping, removal of native oxides, or deposition of an adhesion layer (e.g., titanium nitride (TiN)). In one or more embodiments, an adhesion layer such as titanium nitride is deposited in operation 105. In other embodiments, no adhesion layer is deposited.

[0027] In deposition 110, a process for depositing a molybdenum-containing film on a substrate (or substrate surface) is performed. The deposition process can include one or more operations for forming a film on the substrate. In operation 112, the substrate (or substrate surface) is exposed to a molybdenum precursor to deposit a film on the substrate (or substrate surface). The molybdenum precursor can be any suitable molybdenum-containing compound that can react (i.e., adsorb or chemisorb) with the substrate surface to leave molybdenum-containing species on the substrate surface.

[0028] Current molybdenum precursors for ALD of metal films use halogen- and carbonyl-based substituents, sacrificing reduced reactivity and increased process temperature to provide sufficient stability. Other molybdenum precursors contain anionic nitrogen ligands that can lead to the formation of nitride impurities. Thus, one or more embodiments use 2n-electron donor neutral monodentate ligands, 2n-electron donor neutral bidentate ligands, and 2n-electron donor neutral tridentate ligands to form thermally stable complexes. Hydrogen bonding between the ligands provides further stability. This combination results in a molybdenum precursor with improved thermal stability while maintaining high volatility.

[0029] In one or more embodiments, the molybdenum precursor, specifically the molybdenum(0) precursor, has a structure of formula (I), formula (II), or formula (III): TIFF0007714679000002.tif48170

[0030] [wherein L is one or more of a 2n-electron donor neutral monodentate ligand, a 2n-electron donor neutral bidentate ligand, and a 2n-electron donor neutral tridentate ligand]. In some embodiments, L is independently selected from the group consisting of alkenes, amines, carbonyls, phosphines, and crown sulfurs. The metal coordination complex may be substantially free of halogen and may be substantially free of Mo-O bonds.

[0031] Unless otherwise specified, the terms "lower alkyl", "alkyl", or "alk" as used herein alone or as part of another group include straight-chain hydrocarbons and branched-chain hydrocarbons containing from 1 to 20, or from 1 to 10 carbon atoms in a straight chain, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethyl-pentyl, nonyl, decyl, undecyl, dodecyl, and their various branched-chain isomers. Such groups may optionally contain up to 1 to 4 substituents. Alkyl may be substituted or unsubstituted.

[0032] In one or more embodiments, the metal coordination complex comprises a structure of formula (I), formula (II), or formula (III). The structures of formula (I), formula (II), and formula (III) can be selected from the group consisting of: Mo(CO) n (PMe3) (6-n) [where n is from 1 to 3], Mo(CO) n (CNMe) (6-n) [where n is from 1 to 3], Mo(CO) n (Py) (6-n) [where n is from 1 to 3], Mo(CO) n (SMe2) (6-n) [where n is from 1 to 3], TIFF0007714679000003.tif104170[where n is from 1 to 3], and TIFF0007714679000004.tif31170[where n is from 1 to 3].

[0033] As used herein, "substrate surface" refers to any substrate surface on which a layer can be formed. The substrate surface can have one or more features formed therein, one or more layers formed thereon, and combinations thereof. The substrate (or substrate surface) can be pretreated, for example, by polishing, etching, reduction, oxidation, halogenation, hydroxylation, annealing, baking, etc. prior to the deposition of the molybdenum-containing layer.

[0034] The substrate can be any substrate on which a material can be deposited, such as a silicon substrate, a III-V compound substrate, a silicon germanium (SiGe) substrate, an epi-substrate, a silicon-on-insulator (SOI) substrate, a display substrate, such as a liquid crystal display (LCD), a plasma display, an electroluminescence (EL) lamp display, a solar array, a solar panel, a light-emitting diode (LED) substrate, a semiconductor wafer, etc. In some embodiments, one or more additional layers can be disposed on the substrate such that a molybdenum-containing layer can be at least partially formed thereon. For example, in some embodiments, a layer containing a metal, a nitride, an oxide, etc., or a combination thereof can be disposed on the substrate, and a molybdenum-containing layer can be formed on one or more such layers.

[0035] In operation 114, the processing chamber is optionally purged to remove unreacted molybdenum precursors, reaction products, and by-products. When used in this way, the term "processing chamber" includes the portion of the processing chamber adjacent to the substrate surface without encompassing the entire internal volume of the processing chamber. For example, in a spatially separated sector of the processing chamber, it includes moving the substrate through a gas curtain to a portion or sector of the processing chamber that contains no or substantially no molybdenum precursor, and purging the molybdenum precursor from the portion of the processing chamber adjacent to the substrate surface by any suitable technique, which is not limited to this. In one or more embodiments, purging the processing chamber includes applying a vacuum. In some embodiments, purging the processing chamber includes flowing a purge gas over the substrate. In some embodiments, a portion of the processing chamber refers to a microvolume or small-volume processing station within the processing chamber. The term "adjacent" when referring to the substrate surface means the physical space next to the surface of the substrate that can provide sufficient space for surface reactions (e.g., precursor adsorption) to occur. In one or more embodiments, the purge gas is selected from one or more of nitrogen (N2), helium (He), and argon (Ar).

[0036] In operation 116, the substrate (or substrate surface) is exposed to reactants to form one or more molybdenum films on the substrate. The reactants can react with molybdenum-containing species on the substrate surface to form a molybdenum-containing film. In some embodiments, the reactants include a reducing agent. In one or more embodiments, the reducing agent can include any reducing agent known to those skilled in the art. In other embodiments, the reactants include an oxidizing agent. In one or more embodiments, the oxidizing agent can include any oxidizing agent known to those skilled in the art. In further embodiments, the reactants include one or more of an oxidizing agent and a reducing agent.

[0037] In certain embodiments, the reactant is selected from one or more of 1,1-dimethylhydrazine (DMH), alkylamine, hydrazine, alkylhydrazine, allylhydrazine, hydrogen (H2), ammonia (NH3), alcohol, water (H2O), oxygen (O2), ozone (O3), nitrous oxide (N2O), nitrogen dioxide (NO2), peroxide, N-oxides (e.g., Me3NO, TEMPO), P-oxide (e.g., Et3PO), S-oxides, and their plasmas. In some embodiments, the alkylamine is selected from one or more of tert-butylamine (tBuNH2), isopropylamine (iPrNH2), ethylamine (CH3CH2NH2), diethylamine ((CH3CH2)2NH), or butylamine (BuNH2). In some embodiments, the reactant comprises one or more of the compounds having the formula R’NH2, R’2NH, R’3N, R’2SiNH2, (R’3Si)2NH, (R’3Si)3N; wherein each R’ is independently H or an alkyl group having 1 to 12 carbon atoms. In some embodiments, the alkylamine consists essentially of one or more of tert-butylamine (tBuNH2), isopropylamine (iPrNH2), ethylamine (CH3CH2NH2), diethylamine ((CH3CH2)2NH), butylamine (BuNH2).

[0038] In operation 118, the processing chamber is optionally purged after exposure to the reactant. The purge of the processing chamber in operation 118 may be the same or different from the purge in operation 114. By purging the processing chamber, a portion of the processing chamber, the region adjacent to the substrate surface, etc., unreacted reactants, reaction products, and by-products are removed from the region adjacent to the substrate surface.

[0039] In determination 120, the thickness of the deposited film or the number of cycles of the molybdenum precursor and the reactant are considered. When the deposited film reaches a predetermined thickness or a predetermined number of processing cycles are performed, method 100 proceeds to an optional post-treatment operation 130. If the thickness of the deposited film or the number of processing cycles has not reached a predetermined threshold, method 100 returns to operation 110, exposes the substrate surface to the molybdenum precursor again in operation 112, and continues the subsequent operations.

[0040] The optional post-treatment operation 130 can be, for example, a process to change the film characteristics (e.g., annealing), or a further film deposition process to grow an additional film (e.g., an additional ALD or CVD process). In some embodiments, the optional post-treatment operation 130 can be a process to change the characteristics of the deposited film. In some embodiments, the optional post-treatment operation 130 includes annealing the as-deposited film. In some embodiments, the annealing is performed at a temperature in the range of about 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C, or 1000°C. The annealing environment of some embodiments includes an inert gas (e.g., molecular nitrogen (N2), argon (Ar)), or a reducing gas (e.g., molecular hydrogen (H2) or ammonia (NH3)), or an oxidizing agent, e.g., but not limited to, one or more of oxygen (O2), ozone (O3), or peroxide. The annealing can be performed over any suitable time. In some embodiments, the film is annealed for a predetermined time in the range of about 15 seconds to about 90 minutes, or in the range of about 1 minute to about 60 minutes. In some embodiments, by annealing the as-deposited film, the density increases, the resistivity decreases, and / or the purity of the film increases.

[0041] Method 100 can be performed at any suitable temperature, for example, depending on the molybdenum precursor, reactants, or the heat balance of the device. In one or more embodiments, the use of high-temperature processing may not be desirable for temperature-sensitive substrates such as logic devices. In some embodiments, the exposure to the molybdenum precursor (operation 112) and the reactants (operation 116) is performed at the same temperature. In some embodiments, the substrate is maintained at a temperature in the range of about 20°C to about 400°C, or about 50°C to about 650°C.

[0042] In some embodiments, the exposure to the molybdenum precursor (operation 112) is performed at a different temperature than the exposure to the reactants (operation 116). In some embodiments, the substrate is maintained at a first temperature in the range of about 20°C to about 400°C, or about 50°C to about 650°C for the exposure to the molybdenum precursor and at a second temperature in the range of about 20°C to about 400°C, or about 50°C to about 650°C for the exposure to the reactants.

[0043] In the embodiment shown in FIG. 1, in deposition operation 110, the substrate (or substrate surface) is continuously exposed to the molybdenum precursor and the reactants. In another embodiment (not shown), the substrate (or substrate surface) is simultaneously exposed to the molybdenum precursor and the reactants in a CVD reaction. In a CVD reaction, the substrate (or substrate surface) can be exposed to a gaseous mixture of the molybdenum precursor and the reactants to deposit a molybdenum-containing film having a predetermined thickness. In a CVD reaction, the molybdenum-containing film may be deposited by a single exposure to the mixed reactive gas, or may be exposed to the mixed reactive gas multiple times while purging in between.

[0044] In some embodiments, the formed molybdenum-containing film contains elemental molybdenum. In other words, in some embodiments, the molybdenum-containing film comprises a metal film containing molybdenum. In some embodiments, the metal film consists essentially of molybdenum. As used herein, the term "consisting essentially of molybdenum" means that the molybdenum-containing film is, on an atomic basis, about 80%, 85%, 90%, 95%, 98%, 99%, or 99.5% or more molybdenum. The measurement of the composition of the molybdenum-containing film refers to the bulk portion of the film, excluding the interfacial region where diffusion of elements from adjacent films may occur.

[0045] In other embodiments, the molybdenum-containing film contains molybdenum oxide (MoO x ) with an oxygen content of about 5%, 7.5%, 10%, 12.5%, or 15% or more on an atomic basis. In some embodiments, the molybdenum-containing film contains an oxygen content in the range of about 2% to about 30%, or about 3% to about 25%, or about 4% to about 20% on an atomic basis.

[0046] In other embodiments, the molybdenum-containing film contains molybdenum carbide (MoC x ) with a carbon content of about 5%, 7.5%, 10%, 12.5, or 15% or more on an atomic basis. In some embodiments, the molybdenum-containing film contains a carbon content in the range of about 2% to about 30%, or about 3% to about 25%, or about 4% to about 20% on an atomic basis.

[0047] The deposition operation 110 can be repeated to form one or more of a molybdenum oxide film, a molybdenum carbide film, a molybdenum silicide film, a molybdenum disulfide film, and a molybdenum nitride film having a desired thickness. In some embodiments, the deposition operation 110 is repeated to provide one or more of a molybdenum oxide film, a molybdenum carbide film, a molybdenum silicide film, and a molybdenum nitride film having a thickness in the range of about 0.3 nm to about 100 nm, or about 30 Å to about 10 μM.

[0048] One or more embodiments of the present disclosure are directed to a method of depositing a molybdenum-containing film on a high aspect ratio feature. A high aspect ratio feature is a trench, via, or pillar having a height:width ratio of about 10, 20, or 50 or more, or greater. In some embodiments, the molybdenum-containing film is deposited conformally on the high aspect ratio feature. When used in this way, the conformal film has a thickness in the range of about 80-120% of the thickness at the bottom of the feature, near the top of the feature.

[0049] Some embodiments of the present disclosure are directed to a method of bottom-up gap filling of features. A bottom-up gap filling process fills the feature from the bottom, whereas a conformal process fills the feature from the bottom and the sides. In some embodiments, the feature has a first material (e.g., nitride) at the bottom and a second material (e.g., oxide) on the sidewalls. The molybdenum-containing film is selectively deposited on the first material relative to the second material such that the molybdenum film fills the feature in a bottom-up manner.

[0050] According to one or more embodiments, the substrate is subjected to processing before and / or after the formation of the layer. This processing can be performed in the same chamber or in one or more separate processing chambers. In some embodiments, the substrate is transferred from a first chamber to a separate second chamber for further processing. The substrate may be transferred directly from the first chamber to a separate processing chamber, or may be transferred from the first chamber to one or more transfer chambers and then to a separate processing chamber. Thus, the processing apparatus can include a plurality of chambers in communication with a transfer station. This type of apparatus may be referred to as a "cluster tool" or "cluster system", etc.

[0051] Generally, a cluster tool is a modular system having a plurality of chambers that perform various functions including substrate center detection and orientation, degassing, annealing, deposition, and / or etching. According to one or more embodiments, the cluster tool includes at least a first chamber and a central transfer chamber. The central transfer chamber can store a robot capable of reciprocally transporting substrates between a processing chamber and a load lock chamber. The transfer chamber is typically maintained under reduced pressure conditions and provides an intermediate stage for reciprocating substrates from one chamber to another and / or to a load lock chamber disposed at the front end of the cluster tool. Two well-known cluster tools that can be adapted to the present disclosure are Centura® and Endura®, both of which are available from Applied Materials, Inc., located in Santa Clara, California, USA. However, the exact arrangement and combination of the chambers can be varied for the purpose of performing specific steps of the processes described herein. Other processing chambers that can be used include, but are not limited to, thermal processes such as cyclic layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, chemical cleaning, RTP, plasma nitridation, degassing, orientation, hydroxylation, and other substrate processing. By performing processes within the chambers on the cluster tool, surface contamination of the substrate by impurities in the air can be avoided without oxidizing prior to depositing subsequent films.

[0052] According to one or more embodiments, the substrate is under continuous vacuum or in a "load lock" state and is not exposed to ambient air when moving from one chamber to the next. Thus, the transfer chamber is under vacuum and is "pumped down" under vacuum. An inert gas may be present in the processing chamber or the transfer chamber. In some embodiments, an inert gas is used as a purge gas to remove some or all of the reactants (e.g., one reactant). According to one or more embodiments, a purge gas is injected at the exit of the deposition chamber to prevent reactants (e.g., one reactant) from moving from the deposition chamber to the transfer chamber and / or additional processing chambers. Thus, a flow of inert gas forms a curtain at the exit of the chamber.

[0053] The substrate can be processed in a single substrate deposition chamber where, after a single substrate is loaded, processed, and unloaded, another substrate is processed. The substrate can also be processed in a continuous manner, similar to a conveyor system where multiple substrates are individually loaded into a first portion of the chamber, move through the chamber, and are unloaded from a second portion of the chamber. The shape of the chamber and associated conveyor system can form a linear or curved path. Additionally, the processing chamber can be a carousel where multiple substrates move around a central axis and are exposed to processes such as deposition, etching, annealing, cleaning, etc. throughout the carousel path.

[0054] During processing, the substrate can be heated or cooled. Such heating or cooling can be achieved by any suitable means including, but not limited to, changing the temperature of the substrate support and flowing heated or cooled gas over the substrate surface. In some embodiments, the substrate support includes a heater / cooler that can be controlled to conductively change the substrate temperature. In one or more embodiments, the gas (reactive or inert) used to locally change the substrate temperature is heated or cooled. In some embodiments, a heater / cooler is disposed within the chamber adjacent to the substrate surface to change the substrate temperature by convection.

[0055] The substrate may also be stationary or rotating during processing. A rotating substrate can be rotated (about the substrate axis) continuously or in individual steps. For example, the substrate can be rotated throughout the process, or the substrate can be rotated incrementally between exposures to different reactive or purge gases. Rotating the substrate during processing (either continuously or in steps) can help achieve more uniform deposition or etching, for example, by minimizing the effects of local variations in the geometry of the gas flow.

[0056] Next, the present disclosure will be described with reference to the following examples. Before describing some exemplary embodiments of the present disclosure, it should be understood that the present disclosure is not limited to the details of the configurations or process steps described in the following description. The present disclosure is capable of other embodiments and can be implemented or executed in various ways.

Example

[0057] Example 1: Preparation of Mo(CO)3(PMe3)3 Mo(CO)3(PMe3)3 was prepared by reacting Mo(CO)6 with 3 equivalents of trimethylphosphine in acetonitrile at 90 °C for 3 hours. Removal of acetonitrile under vacuum gave the desired precursor Mo(CO)3(PMe3)3 as a solid with a purity of 98% and a yield of 88%. Melting point 35 °C.

[0058] 1 H NMR (C6D6, 500 MHz, ppm): δ 0.76 - 0.74 (d, CH3, J P-H = 10Hz)

[0059] 13 C NMR (C6D6, 500 MHz, ppm): δ 206.0 (s, CO), 19.3 (s, CH3)

[0060] 311H NMR (C6D6, 500 MHz, ppm): δ -16.9

[0061] Example 2: Preparation of Additional Molybdenum Precursors Similar to Mo(CO)3(PMe3)3, other precursors would be prepared by reacting Mo(CO)6 with the corresponding ligands.

[0062] Example 3: Atomic Layer Deposition of Molybdenum-Containing Films General Procedure: A silicon substrate was placed inside the processing chamber. A molybdenum precursor was flowed into the processing chamber over the silicon substrate in a nitrogen (N2) gas atmosphere, leaving a surface terminated with the molybdenum precursor. Next, the unreacted precursor and by-products were purged out of the chamber. Then, a co-reactant was introduced into the chamber and reacted with the molybdenum species bonded to the surface. Again, the excess co-reactant and by-products were removed from the chamber. The material obtained on the substrate was a molybdenum-containing film.

[0063] For ease of explanation, spatially relative terms such as "directly below," "below," "lower," "above," "upper," etc. can be used to describe the relationship of one element or feature shown in the figures to another (one or more) element or (one or more) feature. It will be understood that the spatially relative terms are intended to encompass different directions of the device in use or operation in addition to the directions shown in the figures. For example, if the device in the figures is turned over, an element described as "below" or "directly below" another element or feature would be oriented "above" the other element or feature. Thus, the exemplary term "below" can encompass both orientations, above and below. The device may be oriented in another direction (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein are to be interpreted accordingly.

[0064] As used in the context of describing the materials and methods discussed in this specification (notably, in the context of the following claims), the terms "a", "an", and "the", and the use of similar designations, should be construed to cover both the singular and the plural forms, unless the specification indicates otherwise or the context clearly contradicts it. The recitation of a range of values in this specification is merely intended to serve as a convenient method of referring individually to each separate value falling within the range, and each separate value is incorporated herein as if it were individually set forth herein. All methods described in this specification can be performed in any suitable order, unless the specification indicates otherwise or the context clearly contradicts it. The use of any and all examples, or exemplary language (e.g., "such as") provided herein is merely intended to make the materials and methods more apparent, and does not impose a limitation on the claims unless otherwise specified. No language in the specification should be construed as indicating that any non-claimed element is essential for the practice of the disclosed materials and methods.

[0065] References throughout this specification to "one embodiment", "a particular embodiment", "one or more embodiments", or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "one or more embodiments", "a particular embodiment", "one embodiment", or "an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the present disclosure. In one or more embodiments, the particular features, structures, materials, or characteristics are combined in any suitable manner.

[0066] The disclosure of this specification has been described with reference to specific embodiments, but these embodiments should be understood to be merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatuses of the present disclosure without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and variations that are within the scope of the appended claims and their equivalents.

Claims

1. A metal coordination complex containing molybdenum(0) and having a structure selected from the group consisting of Mo(CO)n(CNMe)(6−n) [where n is from 1 to 3], Mo(CO)n(Py)(6−n) [where n is from 1 to 3], Mo(CO)n(SMe2)(6−n) [where n is from 1 to 3], [where n is from 1 to 3], and [where n is from 1 to 3].

2. A method for depositing a film, comprising: exposing a substrate to a molybdenum(0) precursor having a structure selected from the group consisting of Mo(CO)n(CNMe)(6−n) [where n is from 1 to 3], Mo(CO)n(Py)(6−n) [where n is from 1 to 3], Mo(CO)n(SMe2)(6−n) [where n is from 1 to 3], [where n is from 1 to 3], and [where n is from 1 to 3], and exposing the substrate to a reactant to form a substantially halogen-free molybdenum-containing film on the surface of the substrate.

3. The method according to claim 2, wherein the reactant comprises one or more of an oxidizing agent and a reducing agent.

4. The method according to claim 2, wherein the molybdenum-containing film comprises one or more of a molybdenum metal (element Mo) film, a molybdenum oxide film, a molybdenum carbide film, a molybdenum silicide film, a molybdenum disulfide film, and a molybdenum nitride film.

5. The method according to claim 2, wherein the substrate is continuously exposed to the molybdenum(0) precursor and the reactant.

6. The method according to claim 2, wherein the substrate is simultaneously exposed to the molybdenum(0) precursor and the reactant.

7. The method according to claim 2, further comprising purging the surface of the substrate of the molybdenum(0) precursor before exposing the substrate to the reactant.

8. The method according to claim 7, wherein purging comprises one or more of applying a vacuum or flowing a purge gas over the surface of the substrate. [where n is from 1 to 3], and ​ ​ ​ The purge gas is nitrogen (N ２ 9. The method of claim 8, wherein the gas comprises one or more of: nitrogen (N), helium (He), and argon (Ar). ​ ​ ​ ​ wherein n is 1 to 3. forming a molybdenum-containing film by a process cycle comprising sequentially exposing a substrate to a molybdenum(0) precursor having a structure selected from the group consisting of: A method comprising:

11. The method of claim 10 , wherein purging comprises one or more of applying a vacuum or flowing a purge gas over the substrate.

12. The purge gas is nitrogen (N ２ 12. The method of claim 11, wherein the gas comprises one or more of: helium (He), and argon (Ar).

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