Method for forming molybdenum silicide layer on surface of substrate

Abstract

Methods of forming a molybdenum silicide layer on a surface of a substrate are disclosed. The method includes disposing a substrate within a reaction chamber, depositing a molybdenum metal layer on a surface of the substrate, and contacting the surface of the molybdenum metal layer with a silicon-containing gas, thereby converting at least a portion of the molybdenum metal layer to a molybdenum silicide layer.

Description

Technical Field

[0001] The present disclosure generally relates to the field of semiconductor processing methods and systems, and the field of device and integrated circuit fabrication. In particular, the present disclosure generally relates to a method of forming a molybdenum silicide layer on a substrate surface. Background Art

[0002] Recently, molybdenum has attracted interest as a metal for forming conductive layers during electronic device manufacturing. For some applications, molybdenum may work well. However, in some cases, device structures with deposited molybdenum may exhibit undesirably high contact resistance. Therefore, there is a need for improved methods of forming conductive layers suitable for electronic device manufacturing.

[0003] Any discussion set forth in this section, including discussion of problems and solutions, has been included in the present disclosure merely to provide context for the present disclosure. Such discussion should not be construed as an admission that any or all information was known at the time the present invention was made, or constitutes prior art. Summary of the invention

[0004] This Summary may introduce some concepts in a simplified form that are further described below. This Summary is not intended to necessarily identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0005] Various embodiments of the present disclosure relate to methods for forming a molybdenum silicide layer on a substrate surface. As described in more detail below, the methods described herein can be used in the manufacture of electronic devices. This method can reduce the complexity and / or cost of manufacturing devices and provide a conductive layer with reduced contact resistance. For example, the methods described herein can be used to form memory, logic, other gate electrode devices, organic light emitting diodes, liquid crystal displays, thin film solar cells, other photovoltaic devices, etc.

[0006] According to an example of the present disclosure, a method for forming a molybdenum silicide layer on a substrate surface is provided. The exemplary method includes placing a substrate in a reaction chamber, depositing a molybdenum metal layer on the surface of the substrate, and contacting the molybdenum metal layer with a silicon-containing gas to convert at least a portion of the molybdenum metal layer into a molybdenum silicide layer. According to an example of the present disclosure, the step of depositing the molybdenum metal layer may include a chemical vapor deposition process. According to a further example of the present disclosure, the step of depositing the molybdenum metal layer may include a thermal cycle deposition process. In this case, the thermal cycle deposition process may include an atomic layer deposition process, and each deposition cycle of the atomic layer process includes: providing a molybdenum precursor to form an adsorbed molybdenum substance on the substrate surface, and providing a reactant to react with the molybdenum substance to form a molybdenum metal layer on the substrate surface. According to an example of the present disclosure, the step of depositing a molybdenum metal layer on the substrate surface may be performed at a substrate temperature between 150°C and 400°C. According to an example of the present disclosure, the molybdenum precursor may include an oxygen-free molybdenum precursor. In this case, the oxygen-free molybdenum precursor includes molybdenum atoms and bis(ethylbenzene) ligands. In this case, the oxygen-free molybdenum precursor may include Mo(EtBz)2. According to an example of the present disclosure, the reactant includes a compound including a halogen atom and a hydrocarbon group. In this case, the halogen atom may include iodine or bromine. In addition, in this case, the reactant may include iodobenzene or 1-iodobutane. In addition, in this case, the reactant may include bromobenzene or 1-bromobutane. According to an example of the present disclosure, the silicon-containing gas has a general formula R a SiX b or R c X d Si-SiR c X d , wherein each X can be independently selected from H, halogen or other ligands, wherein each R can be a C1-C12 organic group, and wherein a is 0, 1, 2 or 3, b is 4-a, c is 0, 1 or 2, and d is 3-c. According to an example of the present disclosure, the step of contacting the molybdenum metal layer with the silicon-containing gas is performed at a substrate temperature between 400°C and 700°C. In this case, the step of contacting the molybdenum metal layer with the silicon-containing gas is performed for a time period between 5 seconds and 600 seconds. According to an example of the present disclosure, the method may also include the step of depositing an additional molybdenum metal layer on the molybdenum silicide layer. According to an example of the present disclosure, the method may also include the step of cleaning the substrate surface before the step of depositing the molybdenum metal layer. In this case, the step of cleaning the substrate surface may include contacting the substrate surface with a first active substance formed using a fluorine-containing gas and a second active substance formed using a hydrogen-containing or NH3-containing gas. In addition, in this case, the first active substance formed using a fluorine-containing gas and the second active substance formed using a hydrogen-containing gas are formed using a remote plasma device.

[0007] According to an additional example of the present disclosure, another method for forming a molybdenum silicide layer on a substrate surface is provided. The method includes placing a substrate in a reaction chamber, the substrate including a contact region of a semiconductor device structure. The method also includes cleaning the surface of the contact region using a first active substance formed using a fluorine-containing gas and a second active substance formed using a hydrogen-containing or NH3-containing gas to form a clean contact surface. The method may also include directly depositing a molybdenum metal layer on the clean contact surface by a cyclic deposition process, the cyclic deposition process including: heating the substrate to a substrate temperature between 150°C and 400°C, providing an oxygen-free molybdenum precursor to the reaction chamber, providing a reactant to the reaction chamber, and contacting the molybdenum metal layer with a silicon-containing gas, thereby converting at least a portion of the molybdenum metal layer into a molybdenum silicide layer, and directly depositing an additional molybdenum metal layer on the molybdenum silicide layer. According to an example of the present disclosure, the step of contacting the molybdenum metal layer with the silicon-containing gas is performed at a substrate temperature between 400°C and 700°C.

[0008] These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying figures.The present invention is not limited to any particular embodiment disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] A more complete understanding of embodiments of the present disclosure may be obtained by referring to the detailed description and claims when considered in conjunction with the following illustrative drawings.

[0010] Figure 1 A method according to an exemplary embodiment of the present disclosure is shown.

[0011] Figures 2 to 5 A structure according to an example of the present disclosure is shown.

[0012] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure. DETAILED DESCRIPTION

[0013] The descriptions of exemplary embodiments of methods, structures, devices, and apparatus provided below are merely exemplary and are for illustrative purposes only; the following descriptions are not intended to limit the scope of the present disclosure or the claims. Furthermore, the recitation of multiple embodiments having the described features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the described features. For example, various embodiments are set forth as exemplary embodiments and may be recited in dependent claims. Unless otherwise indicated, the exemplary embodiments or components thereof may be combined or may be applied separately from each other.

[0014] As described in more detail below, various embodiments of the present disclosure provide methods for forming a molybdenum silicide layer on a substrate surface. The exemplary method can be used to form a molybdenum silicide layer on a substrate surface using a gas-solid reaction. For example, an exemplary method of the present disclosure may include depositing a molybdenum metal layer on a substrate surface, and then contacting the deposited molybdenum metal layer with a silicon-containing gas, which reacts with the molybdenum metal layer through a gas-solid reaction to form a molybdenum silicide layer.

[0015] Compared to other methods, forming a molybdenum silicide layer by adopting a gas-solid reaction can result in a formation process with a reduced thermal budget. For example, directly depositing a molybdenum silicide layer by a chemical vapor deposition process or an atomic layer deposition process may require a high temperature deposition process. As a further example, forming a molybdenum silicide film by a high temperature reaction between a deposited molybdenum layer and an underlying silicon substrate causes a portion of the silicon substrate to be consumed during the reaction, which can change the thickness of the underlying silicon substrate and change the doping profile of the silicon substrate. When a molybdenum silicide layer is used as a constituent layer of an electrical contact stack of a semiconductor device structure, such as on a source / drain region of a transistor, such changes in the thickness and / or doping profile of the source / drain region can have a negative impact on device performance, uniformity, and yield.

[0016] Additionally or alternatively, the exemplary methods can be used to form a molybdenum silicide layer on a clean surface (e.g., from which (e.g., native) oxides have been removed). The methods described herein can be used to form a molybdenum silicide layer to reduce the contact resistance of a contact stack comprising molybdenum. Additionally or alternatively, the methods can be used to form a molybdenum silicide layer using a relatively simple process and / or reduced equipment requirements. Furthermore, in at least some cases, the molybdenum silicide layer can be formed at a relatively low temperature.

[0017] Molybdenum silicide formed according to the methods described herein may be particularly suitable for back-end and middle-end processing of electronic devices such as semiconductor devices. By way of specific example, the methods described herein may be used during the formation of logic devices and memory devices, such as dynamic random access memory (DRAM) devices.

[0018] In the present disclosure, the gas may include a material that is a gas at normal temperature and pressure (NTP), a vaporized solid, and / or a vaporized liquid, and may be composed of a single gas or a gas mixture according to circumstances.

[0019] The terms precursor and reactant may refer to molecules (compounds or molecules containing a single element) that participate in a chemical reaction that produces another compound. A precursor typically comprises a portion that is at least partially incorporated into a compound or element produced by the chemical reaction. The compound or element thus obtained may be deposited on a substrate. A reactant may be an element or compound that is not incorporated into the resulting compound or element to a significant extent. In some cases, the term reactant may be used interchangeably with the term precursor.

[0020] As used herein, the molybdenum precursor includes a gas or a material that can be changed into a gaseous state, and may be represented by a chemical formula including molybdenum. The oxygen-free molybdenum precursor includes a molybdenum compound that does not contain oxygen in its chemical formula.

[0021] As used herein, the silicon-containing gas includes a gas or a material that can be changed into a gaseous state, and may be represented by a chemical formula including silicon.

[0022] As used herein, the term "substrate" may refer to any one or more underlying materials that can be used to form or on which a device, circuit or film can be formed by a method according to an embodiment of the present invention. The substrate may include a bulk material, such as silicon (e.g., single crystal silicon), other IV group materials, such as germanium, or other semiconductor materials, such as II-VI or III-V semiconductor materials, and may include one or more layers covering or located below the bulk material. In addition, the substrate may include various features, such as depressions, protrusions, etc. formed in or on at least a portion of the substrate layer. For example, the substrate may include a bulk semiconductor material and an insulating or dielectric material layer covering at least a portion of the bulk semiconductor material. In addition, the term "substrate" may refer to any one or more underlying materials that can be used or on which a device, circuit or film can be formed. "Substrate" may be continuous or discontinuous; rigid or flexible; solid or porous. "Substrate" may be in any form, such as a powder, a plate or a workpiece. Plate-shaped substrates may include wafers of various shapes and sizes. The substrate may be made of materials such as silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride and silicon carbide. The continuous substrate can extend beyond the boundary of the processing chamber where the deposition process occurs, and can be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate can be provided by a continuous substrate feeding system, which allows the continuous substrate to be manufactured and output in any suitable form. Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, nets, flexible materials, a bundle of continuous filaments or fibers (i.e., ceramic fibers or polymer fibers). The continuous substrate may also include a carrier or thin sheet on which a discontinuous substrate is mounted. For example, the substrate may include a semiconductor material. The semiconductor material may include or be used to form one or more of the source, drain or channel regions of the device. The substrate may also include an interlayer dielectric (e.g., silicon oxide) and / or a high dielectric constant material layer covering the semiconductor material. In this article, a high dielectric constant material or a high-k dielectric material is a material whose dielectric constant is greater than the dielectric constant of silicon dioxide.

[0023] As used herein, the term "layer" may refer to any continuous or non-continuous structure and material, such as a material formed and / or deposited by the methods disclosed herein. For example, a layer may include a two-dimensional material, a three-dimensional material, nanoparticles, or even a partial or complete molecular layer or a partial or complete atomic layer or clusters of atoms and / or molecules. A layer may include a material or layer having pinholes. A layer may be at least partially continuous. A layer may be patterned, such as subdivided, and may be composed of multiple semiconductor devices.

[0024] As used herein, a structure may be or include a substrate as described herein. A structure may include a substrate and one or more layers covering the substrate, such as one or more layers formed by a method according to the present disclosure. The structure may include or be used to form, for example, a via or line in BEOL processing, or a contact or local interconnect in MEOL processing. The structure may also be used to form layers in gate electrodes, to form buried power rails in logic applications, and to form word lines or bit lines in advanced memory applications.

[0025] As used herein, cyclic deposition process and cyclic deposition may refer to the sequential introduction of precursors (and / or reactants) into a reaction chamber to deposit a layer on a substrate, and include process techniques such as atomic layer deposition (ALD), spatial ALD, cyclic chemical vapor deposition (cyclic CVD), and hybrid cyclic deposition processes including an ALD component and a cyclic CVD component. In some cases, a cyclic deposition process may include continuous flow of one or more precursors, reactants, or inert gases, as well as pulsing other precursors or reactants. In addition, the term thermal cyclic deposition process may refer to the sequential introduction of precursors (and / or reactants) into a reaction chamber in a plasma-free environment, i.e., plasma-activated species are not used in a deposition cycle including a thermal cyclic deposition process.

[0026] As used herein, the term "purge" may refer to the process of providing an inert or substantially inert gas to a reaction chamber between two gas pulses that would otherwise react with each other. For example, a purge may be provided between a precursor pulse and a reactant pulse, for example using an inert gas, such as a rare gas, to reduce gas phase interactions that may occur between the precursor and the reactant. It should be understood that the purge may be performed in time or space, or both. For example, in the case of a time purge, a purge step may be used, for example in a time sequence of providing a precursor to a reaction chamber, providing a purge gas to the reaction chamber, and providing a reactant or another precursor to the reaction chamber, wherein the substrate on which the layer is deposited does not move. In the case of a space purge, the purge step may take the form of moving the substrate from a first position where a precursor is (e.g., continuously) supplied to a second position where a reactant or other precursor is (e.g., continuously) supplied via a purge gas curtain.

[0027] In addition, in the present disclosure, any two numbers of a variable may constitute a feasible range for the variable, and any range indicated may include or exclude endpoints. In addition, any values ​​of the variables indicated (regardless of whether they are expressed with the term "about") may refer to exact values ​​or approximate values, and include equivalents, and may refer to average values, medians, representative values, multiple values, etc. In addition, in the present disclosure, the terms including, consisting of, and having independently refer to generally or broadly including, comprising, essentially consisting of, or consisting of in some embodiments.

[0028] In this disclosure, in some embodiments, any defined meaning does not necessarily exclude the ordinary and customary meaning.

[0029] Turning now to the accompanying drawings, Figure 1 Method 100 is shown. Method 100 includes the steps of placing a substrate in a reaction chamber (step 102), depositing a molybdenum metal layer on a surface of the substrate (step 104), contacting the molybdenum metal layer with a silicon-containing gas (step 106), and optionally depositing an additional molybdenum metal layer (step 108). In addition, method 100 may optionally include the step of cleaning the surface of the substrate (step 110).

[0030] During step 102, the substrate is positioned within a reaction chamber. The reaction chamber used during step 102 may be or include a reaction chamber of a chemical vapor deposition reactor system configured to perform a chemical vapor deposition process or a cyclic deposition process. In some embodiments, the reaction chamber used during step 102 may be or include a reaction chamber of an atomic layer deposition reactor system configured to perform a cyclic deposition process.

[0031] The reaction chamber may be a stand-alone reaction chamber or part of a combined tool. The reaction chamber may include a substrate heater to heat the substrate to the substrate temperature mentioned herein. Additionally or alternatively, the reaction chamber may include a thermal treatment device, such as a lamp, to heat the substrate.

[0032] The substrate located within the reaction chamber during step 102 may include one (or more) contact regions of the semiconductor device structure. The contact region may include a source / drain region of the semiconductor device structure. In some embodiments, the substrate includes a plurality of partially fabricated semiconductor device structures, the semiconductor device structure including one or more contact regions, such as one or more source / drain regions. For example, the source / drain region may include doped (p-type or n-type) silicon, germanium, silicon germanium, and may also include a surface layer (e.g., its native oxide). The source / drain region may include a source region and a drain region on which electrical contacts are formed. For example, one or more electrical contact layers formed on the surface of the source / drain region (or directly thereon) may include a molybdenum silicide layer (and optional additional layers) formed by the methods described herein.

[0033] Figure 2 A portion of a substrate suitable for use as a substrate during step 102 is shown. The substrate 200 includes a semiconductor body 202 and a contact region 204 disposed on the semiconductor body. The contact region 204 may include a source / drain region of a semiconductor device structure. For example, the contact region 204 may include doped (p-type or n-type) silicon, germanium, silicon germanium, and may also include a surface 206, which may include, for example, a native oxide. In this case, the contact region 204 may form a portion of a semiconductor device structure, such as a wrap-around gate transistor, a nanosheet transistor, a fork-sheet transistor, a complementary FET (CFET) device, and / or a memory device (e.g., a DRAM). As shown Figure 2 As shown, there may be no liner or barrier layer present, so that the molybdenum silicide layer and subsequently formed additional molybdenum metal layer may be in direct contact with the contact region 204. This allows for low contact resistance and / or relatively less complex manufacturing compared to typical processes that require a barrier layer between the metal and, for example, an interlayer dielectric layer.

[0034] Before depositing the molybdenum metal layer on the substrate surface (step 104), the substrate surface may undergo an optional cleaning step to remove surface contaminants, such as a native oxide layer. Therefore, in some embodiments, method 100 may also include an optional step 110 of cleaning the substrate surface before the step of depositing the molybdenum metal layer (step 104). Step 110 may be performed in a reaction chamber or in another reaction chamber—for example, in the same system module. According to an example of the present disclosure, when the substrate surface is optionally cleaned in another reaction chamber (step 110), the optional cleaning of the substrate surface may be performed before the substrate is placed in the reaction chamber for depositing the molybdenum metal layer.

[0035] During the optional cleaning step 110, a first active material formed using a fluorine-containing gas and a second active material formed using a hydrogen-containing or NH3-containing gas are formed or provided to the reaction chamber to form a clean surface. The surface cleaned according to the examples described herein can produce a higher quality (e.g., less oxygen at the interface) molybdenum silicide compared to molybdenum silicide formed using (e.g.) HF as an etchant. According to examples of the present disclosure, Figure 2 The surface 206 of the contact region 204 shown may be cleaned during a cleaning step 110 to remove any contaminants, such as native oxides, from the surface 206. In this case, step 110 may include cleaning the surface of the contact region 204 using a first reactive species formed using a fluorine-containing gas and a second reactive species formed using a hydrogen-containing or NH3-containing gas to form a clean contact surface.

[0036] According to an example of the present disclosure, an indirect or remote plasma device is used to form a first active material formed using a fluorine-containing gas and a second active material formed using a hydrogen-containing or NH3-containing gas to form a clean surface. The power used to form the plasma can be about 10 to about 1000 W or about 20 to about 200 W for a 300 mm diameter substrate. The plasma on duration can be about 1 to about 60 seconds or about 2 to about 10 seconds.

[0037] The fluorine-containing gas may be or include, for example, one or more of NF3, XeF3, F2, etc. The flow rate of the fluorine-containing gas to the remote or indirect plasma device may be about 1 to about 100 sccm or about 2 to about 100 sccm.

[0038] The hydrogen-containing gas may be or include one or more of NH3, N2 / H2 (e.g., 10-90 vol. % H2), hydrazine, substituted hydrazine, and / or triazine described herein, etc. The flow rate of the hydrogen-containing gas to the remote or indirect plasma device may be about 1 to about 200 sccm or about 10 to about 200 sccm.

[0039] The fluorine-containing gas and the hydrogen-containing or NH3-containing gas can be supplied sequentially to the plasma device and / or to separate plasma devices or different regions of the plasma device. The plasma device may include one or more dedicated regions or units, which may be dedicated to forming respective active species. Alternatively, the first active species formed using the fluorine-containing gas and the second active species formed using the hydrogen-containing gas can be formed using the same plasma unit or region.

[0040] Once the substrate is positioned within the reaction chamber (step 102), and optionally undergoes a cleaning process (step 110), the method 100 may continue with the step of depositing a molybdenum metal layer on the surface of the substrate (step 104).

[0041] The step of depositing a molybdenum metal layer (step 104) can be performed at a substrate temperature between 100° C. and 500° C., or between 150° C. and 400° C., or between 250° C. and 350° C., or between 275° C. and 325° C., or between 280° C. and 320° C. In some embodiments, the step of depositing a molybdenum metal layer (step 104) can be performed at a substrate temperature below 500° C., or below 400° C., or below 300° C., or below 200° C., or below 100° C.

[0042] In addition to controlling the temperature of the substrate, the pressure in the reaction chamber may also be adjusted. For example, in some embodiments of the present disclosure, during step 102, the pressure in the reaction chamber may be less than 760 Torr, or between 0.2 Torr and 760 Torr, between about 1 Torr and 100 Torr, or between about 1 Torr and 10 Torr.

[0043] According to an example of the present disclosure, the step of depositing a molybdenum metal layer (step 104 ) may include a chemical vapor deposition process.

[0044] According to a further example of the present disclosure, the step of depositing a platinum metal layer on the substrate surface (step 104) can include a thermal deposition process, such as a thermal cycle deposition process. In the thermal deposition process, the temperature increased relative to the ambient temperature promotes chemical reactions. Typically, in the absence of other external energy sources (such as plasma, free radicals or other forms of radiation), the temperature increase provides energy for the formation of the platinum metal layer and the subsequent formation of the molybdenum silicide layer. In some embodiments, the cleaning step 110 includes forming a plasma to form an active species as described above.

[0045] According to further examples of the present disclosure, and with reference to Figure 1 , the step of depositing the molybdenum metal layer (step 104) may include a cyclic deposition process. According to examples of the present disclosure, the step of depositing the molybdenum metal layer (step 104) may include a thermal cyclic deposition process. In these examples of the present disclosure, reference Figure 1 , the step of depositing a molybdenum metal layer 104 on the substrate surface includes a cyclic deposition process 112, such as an atomic layer deposition process, which includes providing a molybdenum precursor to form an adsorbed molybdenum species on the substrate surface (step 114), and providing a reactant to react with the molybdenum species to form a molybdenum metal layer on the substrate surface (step 116). As shown in cycle 118, steps 114 and 116 can be repeated, and each cycle includes a separate deposition cycle of the cyclic deposition process 112, such as an atomic layer deposition process. In addition, steps 114 and 116 can be started and / or terminated in any order. In addition, the cyclic deposition process 112 may include one or more (e.g., 1-10 or 1-5) steps 114 and / or 116, and then proceed to the other of steps 114 or 116.

[0046] During step 114, a molybdenum precursor is provided to the reaction chamber. The temperature and pressure within the reaction chamber may be as described above in connection with step 104.

[0047] In some embodiments, the molybdenum precursor is provided as a single compound or a mixture of two or more compounds. In the mixture, the other compounds besides the molybdenum compound may be one or more inert compounds or elements, i.e., inert gases. In some embodiments, the molybdenum precursor is provided in the form of a composition. Compositions suitable for use as compositions may include a molybdenum compound and an effective amount of one or more stabilizers and / or inert gases or carrier gases, such as argon, nitrogen, and / or hydrogen. The composition may be a solution or a gas at NTP.

[0048] According to an example of the present disclosure, the molybdenum precursor may include a molybdenum halide precursor. In a further example, the molybdenum halide precursor may include a molybdenum chalcogenide, and in some embodiments, the molybdenum halide precursor may include a molybdenum chalcogenide halide. For example, the molybdenum chalcogenide halide precursor may include a molybdenum oxyhalide selected from molybdenum oxychloride, molybdenum oxyiodide, and molybdenum oxybromide. In an example embodiment, the molybdenum halide precursor may include molybdenum oxychloride, including but not limited to molybdenum trichloride (V) (MoOCl3), molybdenum tetrachloride (VI) (MoOCl4), and molybdenum dichloride (IV) (MoO2Cl2).

[0049] According to further examples of the present disclosure, the molybdenum precursor may include an oxygen-free molybdenum precursor. In this case, the oxygen-free molybdenum compound contains a molybdenum atom and an organic (e.g., hydrocarbon) ligand. In some embodiments, the molybdenum precursor includes a metal organic compound containing molybdenum. In this case, the molybdenum precursor may be referred to as a metal organic molybdenum precursor. An oxygen-free metal organic molybdenum precursor refers herein to a molybdenum compound containing a molybdenum atom and a hydrocarbon ligand, wherein the molybdenum atom is not directly bonded to a carbon atom. In some embodiments, the oxygen-free metal organic molybdenum precursor contains a molybdenum atom that is not directly bonded to a carbon atom. In some embodiments, the oxygen-free metal organic molybdenum precursor contains two or more molybdenum atoms, none of which is directly bonded to a carbon atom. In some embodiments, the oxygen-free metal organic molybdenum precursor contains two or more metal atoms, wherein at least one metal atom is not directly bonded to a carbon atom.

[0050] In some embodiments, the oxygen-free molybdenum precursor includes an oxygen-free organometallic molybdenum compound containing molybdenum. The oxygen-free organometallic molybdenum precursor refers herein to a molybdenum compound containing a molybdenum atom and an organic (e.g., hydrocarbon) ligand, wherein the molybdenum atom is directly bonded to a carbon atom. In embodiments where the oxygen-free molybdenum organometallic precursor includes two or more metal atoms, one or more (e.g., all) metal atoms may be directly bonded to a carbon atom. In some embodiments, the oxygen-free molybdenum organometallic precursor includes only molybdenum, carbon, and hydrogen. In other words, the oxygen-free molybdenum organometallic precursor does not contain oxygen, nitrogen, or other additional elements. In some embodiments, the oxygen-free molybdenum organometallic precursor includes at least two hydrocarbon ligands. In some embodiments, the oxygen-free molybdenum organometallic precursor includes at least three hydrocarbon ligands. In some embodiments, the oxygen-free molybdenum organometallic precursor includes four hydrocarbon ligands. In some embodiments, the oxygen-free molybdenum organometallic precursor includes hydrocarbon ligands and hydride ligands. In some embodiments, the oxygen-free molybdenum organometallic precursor includes hydrocarbon ligands and two or more hydride ligands. In some embodiments, the oxygen-free molybdenum organometallic precursor includes two hydrocarbon ligands and two hydride ligands. The hydrocarbon ligand described herein may be or include, for example, a C1-C10 hydrocarbon.

[0051] In some embodiments, the oxygen-free platinum precursor comprises one or more cyclic moieties. For example, the oxygen-free platinum precursor may comprise one or more benzene rings. In some embodiments, the oxygen-free platinum precursor comprises two benzene rings. One or both benzene rings may comprise (e.g., C1-C6) hydrocarbon substituents. In some embodiments, each benzene ring of the oxygen-free platinum precursor comprises an alkyl substituent. The alkyl substituent may be a methyl, ethyl, or a straight or branched alkyl group comprising three, four, five, or six carbon atoms. For example, the alkyl substituent of the benzene ring may be an n-propyl or isopropyl group. In addition, the alkyl substituent may be a n-, iso-, tert-, or sec-form of a butyl, pentyl, or hexyl moiety. In some embodiments, the platinum precursor comprises bis(ethylbenzene) platinum, is essentially composed of bis(ethylbenzene) platinum, or is composed of bis(ethylbenzene) platinum.

[0052] In some embodiments, the oxygen-free molybdenum precursor includes a cyclopentadienyl (Cp) ligand. For example, the oxygen-free molybdenum precursor may include, or consist essentially of, MoCp2Cl2 or MoCp2H2, Mo(iPrCp)2Cl2, Mo(iPrCp)2H2, Mo(EtCp)2H2.

[0053] In some embodiments, the oxygen-free molybdenum precursor includes a molybdenum halide compound, which includes or is composed of molybdenum and one or more halogen atoms. The oxygen-free molybdenum precursor may include one or more of the above-mentioned ligands and one or more halogen atoms. Alternatively, the oxygen-free molybdenum precursor compound may be composed of molybdenum and one or more halogen atoms. In some embodiments, the oxygen-free molybdenum precursor includes a molybdenum chloride compound, a molybdenum iodide compound, or a molybdenum bromide compound. As a non-limiting example, the molybdenum halide precursor may include at least one of: molybdenum pentachloride (MoCl5), molybdenum hexachloride (MoCl6), molybdenum hexafluoride (MoF6), molybdenum triiodide (MoI3) or molybdenum dibromide (MoBr2). In some embodiments, the molybdenum halide precursor may include a molybdenum sulfide, and in a specific embodiment, the molybdenum halide precursor may include an oxygen-free molybdenum sulfide halide. Exemplary chalcogenides include sulfur, selenium, and tellurium.

[0054] The duration of step 114 may be between about 0.1 seconds and about 60 seconds, between about 0.1 seconds and about 10 seconds, or between about 0.5 seconds and about 5.0 seconds during each deposition cycle of the cyclic deposition process 112. The flow rate of the oxygen-free molybdenum precursor to the reaction chamber may be less than 1000 sccm, or less than 500 sccm, or less than 100 sccm, or less than 10 sccm, or even less than 1 sccm, or range from about 1 to 2000 sccm, from about 5 to 1000 sccm, or from about 10 to about 500 sccm.

[0055] During step 116, reactants are provided to the reaction chamber. Exemplary reactants suitable for step 116 may include a reducing agent. Exemplary reducing agents include one or more of the following: forming gas (H2+N2), ammonia (NH3), hydrazine (N2H4), alkyl hydrazines (e.g., tert-butyl hydrazine (C4H4), 12 N2)), molecular hydrogen (H2), hydrogen atom (H), (e.g. C1C4) alcohol, (e.g. C1-C4) aldehyde, (e.g. C1-C4) carboxylic acid, (e.g. B1-B12) borane or amine.

[0056] According to further examples of the present disclosure, reactants may include halogen reactants. In certain embodiments, halogen reactants include halogenated hydrocarbons containing only one halogen atom. Halogen reactants may include two or three carbon atoms. In addition, halogen reactants may include four, five, six, seven or eight carbon atoms. Halogen reactants may include straight, branched, cyclic and / or aromatic carbon chains. For example, halogen reactants may include ethane halides, propane, benzene, 2-methylpropane, 2,2-dimethylpropane (neopentane), n-butane, 2-methylbutane, 2,2-dimethylbutane, n-pentane, 2-methylpentane, 3-methylpentane or n-hexane. In certain embodiments, hydrocarbons include aryls. In certain embodiments, halogen reactants include halogenated benzenes.

[0057] In certain embodiments, the halogen reactant comprises only one halogen atom. The halogen atom is selected from bromine, iodine, fluorine or chlorine. The position of the one carbon atom in the carbon chain can vary. In certain embodiments, it is located at the end of the carbon chain, but in certain embodiments, it is away from the end of the carbon chain. In the case of cyclic hydrocarbons, the halogen can be located at any carbon atom. It will be apparent to those skilled in the art that the position of a given carbon atom in the carbon chain limits the number of available potential substituents. In certain embodiments, the halogen reactant comprises iodobenzene or 1-iodobutane, or is substantially composed of or is composed of. In certain embodiments, the halogen reactant comprises bromobenzene or 1-bromobutane, or is substantially composed of or is composed of.

[0058] In some embodiments, the halogen reactant includes an allylic halide. The halogen reactant may include a halogen atom attached to a corresponding amount of an allylic carbon in the allylic halide.

[0059] In some embodiments, the halogen reactant includes a vinyl halide. The halogen reactant may include a halogen atom attached to a corresponding amount of a vinyl carbon in the vinyl halide.

[0060] During step 116, the flow rate of the reactant to the reaction chamber can be greater than zero and less than 30 slm, or less than 15 slm, or less than 10 slm, or less than 5 slm, or less than 1 slm, or even less than 0.1 slm. For example, the flow rate can be between about 0.1 and 30 slm, from about 5 to 15 slm, or equal to or greater than 10 slm. In the case of a cyclic deposition process, the reactant can be pulsed—for example, for a duration between about 0.01 seconds and about 180 seconds, between about 0.05 seconds and about 60 seconds, or between about 0.1 seconds and about 30 seconds.

[0061] The oxygen-free molybdenum precursor and / or reactant can be purged from the reaction chamber—for example, after each pulse and / or upon completion of steps 114, 116, and / or each deposition cycle of the cyclic deposition process (step 112). The purging can be performed in time or space, or both. The purge time can be, for example, from about 0.01 seconds to about 20 seconds, from about 0.05 seconds to about 20 seconds, or from about 1 second to about 20 seconds, or from about 0.5 seconds to about 10 seconds, or from about 1 second to about 7 seconds. The flow rate of the purge gas to the reaction chamber can be less than 1000 sccm, or less than 500 sccm, or less than 100 sccm, or less than 10 sccm, or even less than 1 sccm, or ranges from about 1 to 2000 sccm, from about 5 to 1000 sccm, or from about 10 to about 500 sccm.

[0062] In some embodiments, the oxygen-free molybdenum precursor may be pulsed more than once, for example, twice, three times, or four times, before the reactant is pulsed into the reaction chamber. Similarly, the reactant may have more than one pulse, for example, two, three, or four pulses, before the oxygen-free molybdenum precursor is pulsed (i.e., provided) into the reaction chamber.

[0063] The cyclic deposition process (step 112) is repeated until an end criterion is met. For example, the end criterion can be based on the number of deposition cycles performed, or the desired thickness of the deposited molybdenum metal film.

[0064] Figure 3 The structure 300 is shown after completing step 104. As shown, a molybdenum metal layer 302 is deposited on the cleaned contact surface 206 of the contact area 204.

[0065] The molybdenum metal layer 302 may be at least partially in elemental form. Therefore, the oxidation state of the molybdenum metal layer may be zero. Therefore, the molybdenum metal layer 302 may include molybdenum, or may be substantially composed of or composed of it. According to an example of the present disclosure, the molybdenum metal layer 302 includes, for example, about 60 to about 99 atomic percent (atomic %) of molybdenum, or about 75 to about 99 atomic % of molybdenum, or about 75 to about 95 atomic % of molybdenum, or about 80 to about 95 atomic % of molybdenum. The molybdenum layer 302 deposited by the method according to the present disclosure may include, for example, about 80 atomic %, about 83 atomic %, about 85 atomic %, about 87 atomic %, about 90 atomic %, about 95 atomic %, about 9 atomic % or about 99 atomic % of molybdenum. The molybdenum metal layer composed of molybdenum may include an acceptable amount of impurities, such as carbon, chlorine or other halogens and / or hydrogen, which may be derived from one or more precursors used to deposit the molybdenum layer.

[0066] In some embodiments, the molybdenum metal layer 302 may include less than about 20 atomic %, less than about 15 atomic %, less than about 10 atomic %, less than about 8 atomic %, less than about 6 atomic %, less than about 5 atomic %, less than about 4.5 atomic % or less than about 3 atomic % carbon.

[0067] According to an example of the present disclosure, the cyclic deposition process 112 may include depositing a molybdenum metal layer 302 (eg, a clean contact surface 206) on a surface of the substrate. Figure 3 ) to an average layer thickness between 1 nm and 50 nm, or between 2 nm and 25 nm, or between 3 nm and 15 nm. According to an example of the present disclosure, the molybdenum metal layer is deposited to an average layer thickness between 1 nm and 10 nm, or between 2 nm and 8 nm, or between 3 nm and 5 nm. According to an example of the present disclosure, the molybdenum metal layer is deposited to an average layer thickness of less than 10 nm, or less than 8 nm, or less than 6 nm, or less than 4 nm, or less than 2 nm, or less than 1 nm.

[0068] After completing the deposition of the molybdenum metal layer (step 104), the method 100 proceeds to step 106, which includes contacting the molybdenum metal layer with a silicon-containing gas, thereby converting at least a portion of the molybdenum metal layer into a molybdenum silicide layer. The step of contacting the molybdenum metal layer with the silicon-containing gas (step 106) includes providing a silicon-containing gas to the reaction chamber, wherein the silicon-containing gas contacts the molybdenum metal layer disposed on the substrate. According to an example of the present disclosure, the contact of the molybdenum metal layer with the silicon-containing gas results in a gas-solid reaction between the molybdenum metal layer and the silicon-containing gas. In this case, the gas-solid reaction causes the molybdenum metal layer to be converted into a metal silicide layer. In this case, parameters including but not limited to substrate temperature, pressure, selection of silicon-containing gas, and contact duration between silicon-containing gas and the molybdenum metal layer can be adjusted to convert at least a portion of the molybdenum metal layer into a metal silicide layer. In addition, in this case, the substrate temperature and the contact duration between the silicon-containing gas and the molybdenum metal layer can be adjusted to convert the total thickness of the molybdenum metal layer into a molybdenum silicide layer. The term "total thickness" as used herein refers to the total volume of the molybdenum metal layer, and similarly "converting the total thickness of the molybdenum metal layer into the molybdenum silicide layer" means that the molybdenum metal layer is completely converted into the molybdenum silicide layer.

[0069] The step of contacting the molybdenum metal layer with the silicon-containing gas (step 106) can be performed at a substrate temperature between 300° C. and 800° C., or between 350° C. and 750° C., or between 400° C. and 700° C. In some embodiments, the step of contacting the molybdenum metal layer with the silicon-containing gas (step 114) can be performed at a substrate temperature below 800° C., or below 700° C., or below 600° C., or below 500° C., or below 400° C.

[0070] According to an example of the present disclosure, a molybdenum metal layer may be deposited on a substrate including a memory device structure, such as a dynamic random access memory (DRAM) device structure. In this case, the step of contacting the molybdenum metal layer with a silicon-containing gas (step 106) may be performed at a substrate temperature of less than 700°C, or less than 600°C, or less than 500°C, or less than 400°C, or between 400°C and 700°C.

[0071] According to a further example of the present disclosure, a molybdenum metal layer may be deposited on a substrate including a logic device such as a transistor device structure. In this case, the step of contacting the molybdenum metal layer with a silicon-containing gas (step 106) may be performed at a substrate temperature of less than 450°C, or less than 400°C, or less than 350°C, or less than 300°C, or less than 200°C, or between 200°C and 450°C.

[0072] In addition to controlling the temperature of the substrate, the pressure in the reaction chamber may also be adjusted. For example, in some embodiments of the present disclosure, during step 106, the pressure in the reaction chamber may be less than 760 Torr, or between 0.2 Torr and 760 Torr, between about 1 Torr and 100 Torr, or between about 1 Torr and 10 Torr. In some embodiments, during step 106, the pressure in the reaction chamber is less than atmospheric pressure, or between 0.1 mTorr and 10 Torr, or between 0.1 Torr and 5 Torr, or between 1 Torr and 2 Torr.

[0073] During step 106, a silicon-containing gas is provided to the reaction chamber, wherein the gas contacts the molybdenum metal layer. In some cases, the silicon-containing gas includes a silicon-containing gas having the general formula R a SiX b or R c X d Si-SiR c X d Compounds wherein each X can be independently selected from H, halogen or other ligands, wherein each R can be a C1-C12 organic group, and wherein a is 0, 1, 2 or 3, b is 4-a, c is 0, 1 or 2, and d is 3-c. If a is two or three, or c is two, each R can be independently selected. In certain embodiments, each R is selected from alkyl and aryl. For the sake of clarity, X can represent different (e.g., independently selected) ligands. Therefore, in certain embodiments, the auxiliary reaction product can be, for example, SiH2Br2, SiH2I2 or SiH2Cl2.

[0074] In some embodiments, X is hydrogen, substituted or unsubstituted alkyl or aryl, or halogen. In some embodiments, X is H. In some embodiments, X is alkyl or aryl. In some embodiments, X is C1 to C4 alkyl. In some embodiments, X is substituted alkyl or aryl. In some embodiments, X is substituted alkyl or aryl, wherein the substituent includes silicon. In some embodiments, X is selected from H, Me, Et, nPr, iPr, nBu, tBu, M'Me3, M'Et3, M'Pr3, M'Bu3, Cl, Br or I, wherein M' is Si.

[0075] In some embodiments, the silicon-containing gas may have the formula R3Si X ,R2SiX2,R S In some embodiments, the silicon-containing gas is not SiH4. In some embodiments, the silicon-containing gas is not SiH2Me2. In some embodiments, the silicon-containing gas is not SiH2Et2. In some embodiments, the silicon-containing gas is not Si2H2.

[0076] In some cases, an exemplary silicon-containing gas suitable for use during step 106 may be composed of silicon and hydrogen. For example, the silicon-containing gas may include silanes, such as silane (SiH4), disilane (Si2H6), trisilane (Si3H8), tetrasilane (Si4H 10 ) or with the general empirical formula Si x H (2x+2) of higher silanes.

[0077] In some cases, the silicon-containing gas may include aminosilanes, such as silanediamine N,N,N′,N-tetraethyl(C8H 22 N2Si), BTBAS (bis(tert-butylamino)silane), BDEAS (bis(diethylamino)silane) or TDMAS (tris(dimethylamino)silane), hexa(ethylamino)disilane (Si2(NHC2H5)6.

[0078] According to further examples of the present disclosure, the silicon-containing gas does not include oxygen-containing compounds. In some cases, step 106 includes providing another gas, such as a hydrogen-containing gas (eg, H2, NH3, etc.), within the reaction chamber.

[0079] The duration of step 106 of contacting the molybdenum metal layer with the silicon-containing gas may be between 0.1 seconds and 600 seconds, between 10 seconds and 300 seconds, or between 60 seconds and 180 seconds.

[0080] According to a further example of the present disclosure, the step of depositing a molybdenum metal layer (step 104) and the step of contacting the molybdenum metal layer with a silicon-containing gas (step 106) can be repeated in a cyclic process to form a molybdenum silicide layer of a desired thickness. When a molybdenum silicide layer with an increased thickness is required, repeated cycles between steps 104 and 106 can be performed. For example, repeated cycles between steps 104 and 106 in a cyclic process can be performed to form a molybdenum silicide layer with a thickness greater than 10 nm, or greater than 20 nm, or greater than 30 nm, or greater than 40 nm, or greater than 50 nm, or between 10 nm and 50 nm.

[0081] Figure 4 4 shows a structure 400 after completing step 106. As shown, a molybdenum silicide layer 402 is formed on the contact area 204. As shown, the molybdenum silicide layer 402 is formed directly on the contact area 204 without any remaining portion of the previous molybdenum metal layer 302 ( Figure 3 As previously mentioned, existing methods of forming a molybdenum silicide layer result in variations in the thickness / doping profile of the layer directly below the metal silicide. Figure 4As shown, when forming the overlying metal silicide layer 402, the underlying contact region 204 maintains its original thickness, so there is no detrimental thickness variation or change in the doping profile of the contact region 204. For example, the contact region 204 has an initial thickness before forming the molybdenum silicide layer, and maintains the initial thickness after converting the entire thickness of the molybdenum metal layer into the molybdenum silicide layer 402. Similarly, the contact region 204 has an initial doping concentration profile before forming the molybdenum silicide layer 402, and maintains the initial doping concentration profile after converting the entire thickness of the molybdenum metal layer into the molybdenum silicide layer 402.

[0082] The molybdenum silicide layer 402 may include, consist essentially of, or consist of molybdenum silicide. The layer consisting of molybdenum silicide may include acceptable amounts of impurities, such as carbon, chlorine or other halogens, and / or hydrogen, which may originate from one or more precursors used to deposit the molybdenum metal layer and convert the molybdenum metal layer into a molybdenum metal silicide layer by providing a silicon-containing gas into the reaction chamber.

[0083] The average layer thickness of the molybdenum silicide layer 402 can be, for example, between 1 nm and 50 nm, or between 2 nm and 25 nm, or between 3 nm and 15 nm. According to a further example of the present disclosure, the average layer thickness of the molybdenum silicide layer 402 is between 1 nm and 10 nm, or between 2 nm and 8 nm, or between 3 nm and 5 nm. According to a further example of the present disclosure, the molybdenum silicide layer is deposited to an average layer thickness of less than 10 nm, or less than 8 nm, or less than 6 nm, or less than 4 nm, or less than 2 nm, or less than 1 nm.

[0084] Method 100( Figure 1 ) may include an optional step 108 for depositing an additional metal layer on the molybdenum silicide layer. During step 108, an additional metal layer is deposited on the molybdenum silicide layer. According to an example of the present disclosure, the additional metal layer may include an additional molybdenum metal layer and is deposited directly on the molybdenum silicide layer. Optional step 108 may be the same or similar to step 104, except that step 112 is not required, but may be cyclic. In particular, step 108 may include using any oxygen-free molybdenum precursor and reactant mentioned above in conjunction with steps 114 and / or 116. Step 108 may be continuous (e.g., a CVD process) or may be a cyclic process as described above in conjunction with step 112. In addition, the oxygen-free molybdenum precursor, the oxygen-free molybdenum precursor flow rate, and the oxygen-free molybdenum precursor flow duration during step 108 may be as described above in conjunction with step 104. Similarly, the reactants, reactant flow rates, and reactant flow duration during step 108 may be as described above in conjunction with step 104. Similarly, the temperature and pressure in the reaction chamber may be as described above in conjunction with step 104.

[0085] Figure 5The structure 500 after completing step 108 is shown. As shown, the additional metal layer 502 is deposited on the metal silicide layer 402. The additional metal layer 502 may include an additional molybdenum metal layer directly deposited on the metal silicide layer 402, thereby forming a contact stack 504 including the metal silicide layer 402 and the additional molybdenum metal layer 502. As shown, the metal silicide layer 402 is directly disposed between the contact region 204 and the additional molybdenum metal layer 502, without any additional intermediate layer contacting the contact region 204 and potentially affecting the contact resistance of the contact stack 504. According to an example of the present disclosure, the contact region 204 may include a source / drain region of a semiconductor device structure, and as shown, the contact stack 504 may be directly formed on the source / drain region of the semiconductor device structure. In this case, the molybdenum silicide layer is directly disposed between the source / drain region and the additional molybdenum metal layer 502, and the molybdenum silicide layer 402 thus forms an interface layer between the source / drain region and the additional molybdenum metal layer 502. According to an example of the present disclosure, before the contact stack 504 is formed directly on the source / drain region, the source / drain has an initial thickness, and after the contact stack 504 is formed directly on the source / drain region, the source / drain region maintains the initial thickness. Similarly, before the contact stack 504 is formed directly on the source / drain region, the source / drain region has an initial doping concentration profile, and after the contact stack 504 is formed directly on the source / drain region, the source / drain region maintains the initial doping profile.

[0086] The additional molybdenum metal layer 502 may have an average layer thickness between 1 nm and 200 nm, or between 10 nm and 150 nm, or between 25 nm and 100 nm, or between 25 nm and 50 nm. According to an example of the present disclosure, the additional molybdenum metal layer 502 may have an average layer thickness of less than 250 nm, or less than 150 nm, or less than 100 nm, or less than 50 nm, or less than 25 nm.

[0087] According to a further example of the present disclosure, the additional metal layer 502 may include an additional tungsten layer or an additional cobalt layer having an average layer thickness between 1 nm and 200 nm or between 10 nm and 150 nm or between 25 nm and 100 nm or between 25 nm and 50 nm. According to an example of the present invention, the additional tungsten or cobalt metal layer may have an average layer thickness of less than 250 nm or less than 150 nm or less than 100 nm or less than 50 nm or less than 25 nm.

[0088] The exemplary embodiments disclosed above do not limit the scope of the present invention, as these embodiments are merely examples of embodiments of the present invention, and the scope of the present invention is defined by the appended claims and their legal equivalents. Any equivalent embodiments are within the scope of the present invention. In fact, various modifications of the present disclosure, such as alternative useful combinations of the described elements, in addition to those shown and described herein, will become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

1. A method for forming a molybdenum silicide layer on a substrate surface, the method comprising: placing a substrate in a reaction chamber; depositing a molybdenum metal layer on a surface of a substrate; as well as The molybdenum metal layer is contacted with a silicon-containing gas to convert at least a portion of the molybdenum metal layer into a molybdenum silicide layer.

2. The method according to claim 1, wherein: The step of depositing the molybdenum metal layer includes a chemical vapor deposition process.

3. The method according to claim 1, wherein: The step of depositing the molybdenum metal layer includes a thermal cycle deposition process.

4. The method according to claim 3, wherein: The thermal cycle deposition process includes an atomic layer deposition process, and each deposition cycle of the atomic layer deposition process includes: providing a molybdenum precursor to form an adsorbed molybdenum species on the substrate surface; and A reactant is provided to react with the molybdenum species to form a molybdenum metal layer on the surface of the substrate.

5. The method according to claim 4, wherein: The molybdenum precursor includes an oxygen-free molybdenum precursor.

6. The method according to claim 5, wherein: The oxygen-free molybdenum precursor comprises molybdenum atoms and bis(ethylbenzene) ligands.

7. The method according to claim 6, wherein: The oxygen-free molybdenum precursor includes Mo(EtBz)2.

8. The method according to any one of claims 4 to 7, wherein: The reactants include compounds consisting of halogen atoms and hydrocarbon groups.

9. The method according to claim 8, wherein: The halogen atom is iodine or bromine.

10. The method according to claim 9, wherein: The reactants include iodobenzene or 1-iodobutane.

11. The method according to claim 9, wherein: The reactants include bromobenzene or 1-bromobutane.

12. The method according to any one of claims 1 to 11, wherein: The step of depositing the molybdenum metal layer is performed at a substrate temperature between 150°C and 400°C.

13. The method according to any one of claims 1 to 12, wherein: The silicon-containing gas has the general formula R a SiX b or R c X d Si-SiR c X d , wherein each X can be independently selected from H, halogen or other ligands, wherein each R can be a C1-C12 organic group, and wherein a is 0, 1, 2 or 3, b is 4-a, c is 0, 1 or 2, and d is 3-c.

14. The method according to any one of claims 1 to 13, wherein: The step of contacting the molybdenum metal layer with a silicon-containing gas is performed at a substrate temperature between 400°C and 700°C.

15. The method according to any one of claims 1 to 14, further comprising the step of depositing an additional molybdenum metal layer on the molybdenum silicide layer.

16. The method according to any one of claims 1 to 15, further comprising the step of cleaning the surface of the substrate before the step of depositing the molybdenum metal layer.

17. The method according to claim 16, wherein: The step of cleaning the substrate surface includes contacting the substrate surface with a first active material formed using a fluorine-containing gas and a second active material formed using a hydrogen-containing or NH 3 -containing gas.

18. A semiconductor device structure formed according to any one of claims 1 to 17.

19. A method for forming a molybdenum silicide layer on a substrate surface, the method comprising: placing a substrate in a reaction chamber, the substrate including a contact region of a semiconductor device structure; cleaning the surface of the contact region using a first active material formed using a fluorine-containing gas and a second active material formed using a hydrogen-containing or NH 3 -containing gas to form a clean contact surface; The molybdenum metal layer is deposited directly on the clean contact surface by a cyclic deposition process comprising: heating the substrate to a substrate temperature between 150° C. and 400° C.; providing an oxygen-free molybdenum precursor to a reaction chamber; providing reactants to the reaction chamber; contacting the molybdenum metal layer with a silicon-containing gas to convert at least a portion of the molybdenum metal layer into a molybdenum silicide layer; and An additional molybdenum metal layer is deposited directly on the molybdenum silicide layer.

20. The method according to claim 19, wherein: The step of contacting the molybdenum metal layer with a silicon-containing gas is performed at a substrate temperature between 400°C and 700°C.

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