Plasma enhanced molybdenum deposition

Abstract

Embodiments of the present disclosure relate to methods of depositing a molybdenum film directly on a substrate surface (e.g., a low-kappa dielectric material) by exposing the substrate surface to a molybdenum-containing precursor and an organosilane reducing agent at a temperature of less than or equal to 450 DEG C. The molybdenum-containing precursor comprises one or more of molybdenum pentachloride (MoCl5), molybdenum dioxide dichloride (MoO2Cl2), molybdenum tetrachloride (MoOCl4), molybdenum hexafluoride (MoF6), molybdenum hexacarbonyl, bis (tertiary butyl imino)-bis (dimethylamino) molybdenum or bis (ethylbenzene) molybdenum. In some embodiments, the organosilane reducing agent includes a trimethylsilyl compound, such as 1, 4-bis (trimethylsilyl)-2-methyl-2, 5-cyclohexadiene.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to the field of electronic device fabrication, and in particular to integrated circuit (IC) fabrication. In particular, embodiments of the present disclosure relate to plasma-enhanced deposition of molybdenum at reduced temperatures. Background Art

[0002] As circuit integration increases, there is a growing demand for greater consistency and process control over layer thickness. Consequently, various techniques have been developed to cost-effectively deposit layers onto substrates while maintaining control over the layer's properties. Chemical vapor deposition (CVD) is one of the most common deposition processes used to deposit layers onto substrates.

[0003] A variation of CVD that exhibits excellent step coverage is cyclic deposition or atomic layer deposition (ALD). ALD utilizes a chemical adsorption technique to transfer precursor molecules onto a substrate surface in sequential cycles. An ALD cycle involves exposing the substrate surface to a first precursor, a purge gas, a second precursor, and a purge gas. The first and second precursors react to form a product compound, such as a film, on the substrate surface. The ALD cycle is repeated to build the layer to the desired thickness.

[0004] The increasing complexity of advanced microelectronic devices places stringent demands on currently used deposition technologies. Molybdenum and molybdenum-based films possess attractive material and conductive properties. These films have been proposed and tested for applications ranging from front-end to back-end of semiconductor and microelectronic device fabrication.

[0005] While not wishing to be bound by any particular theory or principle, it is believed that molybdenum cannot be deposited and grown directly on dielectric surfaces, and that molybdenum can be deposited and grown on metallic surfaces.

[0006] Molybdenum films can be used as low-resistivity electrical connections in the form of vertical and / or horizontal interconnects through which current flows, as vias between adjacent metal layers, and as contacts between the first metal layer on the substrate and the device. For example, in both full coverage and gap fill applications, a liner film (e.g., a TiN liner film) is typically deposited on the dielectric surface to achieve repeatable molybdenum deposition. In gap fill applications, TiN is deposited in the gap to achieve both low resistivity and conformal deposition. Conformal deposition is often required to uniformly deposit metal films over three-dimensional structures including high aspect ratio features.

[0007] There is a continuing need for improved metal liners or metal layers to provide lower resistivity molybdenum films. Consequently, there is a need for improved materials and methods for depositing molybdenum films on dielectric surfaces to provide conformal molybdenum deposition with improved film properties. Summary of the Invention

[0008] One or more embodiments relate to a deposition method comprising depositing a molybdenum film directly on a substrate surface by exposing the substrate surface to a molybdenum-containing precursor and an organosilane reducing agent at a temperature less than or equal to 450°C, the molybdenum film having a molybdenum-carbon (Mo-C) bond; and treating the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film.

[0009] Additional embodiments relate to a method for filling a feature formed on a surface of a substrate. The method for filling the feature comprises: conformally depositing a first molybdenum film directly on the feature by exposing the feature to a molybdenum-containing precursor at a temperature of less than or equal to 450° C. and an organosilane reducing agent, the first molybdenum film having a molybdenum-silicon (Mo-C) bond, the feature comprising a surface defining a trench, the trench comprising a top surface, a bottom surface comprising a metal material, and two opposing sidewalls comprising a low-K dielectric material; treating the first molybdenum film with a plasma to remove carbon and form a substantially carbon-free first molybdenum film; and depositing a second molybdenum film on the substantially carbon-free first molybdenum film to fill the feature. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In order to be able to understand in detail the manner in which the features described above of the present disclosure are described, a more particular description of the present disclosure, briefly summarized above, may be made with reference to embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of the present disclosure and, therefore, should not be considered as limiting the scope of the present disclosure, as the present disclosure may admit to other equally effective embodiments. The embodiments as described herein are illustrated by way of example and not by way of limitation in the figures of the accompanying drawings, in which like reference numerals indicate similar elements.

[0011] Figure 1 A process flow diagram illustrating a method according to one or more embodiments;

[0012] Figure 2 illustrates a cross-sectional isometric view of a processing chamber according to one or more embodiments;

[0013] Figure 3 illustrates a cross-sectional view of a processing chamber according to one or more embodiments;

[0014] Figure 4A illustrates a diagrammatic cross-sectional view of a dielectric layer on a substrate surface according to one or more embodiments;

[0015] Figure 4B Illustrated is a diagram showing a method of performing a multi-step process according to one or more embodiments. Figure 4A A diagrammatic cross-sectional view of a molybdenum-containing liner on a dielectric layer on a substrate surface in FIG;

[0016] Figure 4C Deposition according to one or more embodiments is illustrated in FIG. Figure 4B A diagrammatic cross-sectional view of a molybdenum film on a molybdenum liner in FIG.

[0017] Figure 5A illustrates a diagrammatic cross-sectional view of a feature on a substrate according to one or more embodiments;

[0018] Figure 5B Illustrated in accordance with one or more embodiments Figure 5A a diagrammatic cross-sectional view of a molybdenum-containing liner on a dielectric region of a feature on a substrate in FIG; and

[0019] Figure 5C Deposition according to one or more embodiments is illustrated in FIG. Figure 5B Schematic cross-sectional view of a molybdenum film on a molybdenum-containing liner in FIG. DETAILED DESCRIPTION

[0020] Before describing several example embodiments of the present disclosure, it will be understood that the present disclosure is not limited to the details of the architecture or processing steps described later in the specification. The present disclosure is capable of other embodiments and may be implemented or performed in various ways. As used herein, the term "about" means approximately or almost, and in the context of a stated value or range, means a variation of ±15% or less of that value. For example, a difference in a value of ±14%, ±10%, ±5%, ±2%, or ±1% would satisfy the definition of about.

[0021] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which film processing is performed during a manufacturing process. For example, substrate surfaces on which processing may be performed include 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 material such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. In some embodiments, the substrate includes one or more of titanium nitride (TiN), titanium silicide (TiSi), tungsten titanium silicide, clean silicon (Si), boron-doped silicon germanium (SiGeB), clean silicon phosphorus (SiP), titanium aluminum (TiAl), ruthenium (Ru), tungsten (W), and molybdenum (Mo). The substrate includes, without limitation, a semiconductor wafer.

[0022] The substrate may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to film treatments performed directly on the surface of the substrate itself, any of the film treatment steps disclosed herein may also be performed on underlying layers formed on the substrate, as described in greater detail below, and the term "substrate surface" is intended to include such underlying layers as the context dictates. Thus, for example, where a film / layer or portion of a film / layer has been deposited onto the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0023] As used herein, the term "substrate surface" refers to any substrate surface on which a layer may be formed. A substrate surface may have one or more features formed therein, one or more layers formed thereon, and combinations thereof. The shape of a feature may be any suitable shape, including but not limited to spikes, grooves, and cylindrical through-holes. When used in this manner, the term "feature" refers to any intentional surface irregularity. Suitable examples of features include, but are not limited to, grooves, spikes, and through-holes, wherein a groove has a top, two sidewalls, and a bottom, a spike has a top and two sidewalls extending upward from the surface, and a through-hole has sidewalls extending downward from the surface and a bottom. In some embodiments, the bottom of the through-hole comprises an open bottom defined or delimited by an underlying material, such as a dielectric material that also defines the two sidewalls, or the material below the bottom may be a conductor, such as a metal (e.g., copper), which may be the same or different from the sidewall material.

[0024] As used in this specification and the appended claims, the term "selective" refers to a treatment that acts with a greater effect on a first surface than on a second surface. Such a treatment will be described as acting "selectively" on the first surface as compared to the second surface. The term "over" used in this manner does not imply a physical orientation of one surface on top of another, but rather a relationship of the thermodynamic or kinetic properties of the chemical reactions of one surface relative to the other surface.

[0025] The term "on" indicates that there is direct contact between elements. The term "directly on" indicates that there is direct contact between elements with no intervening elements.

[0026] As used in this specification and the appended claims, the terms "precursor," "reactant," "reactant gas," and the like are used interchangeably to refer to any gaseous species that can react with a substrate surface.

[0027] As used herein, the term "liner" refers to a layer formed along at least a portion of the sidewalls and / or lower surface of an opening, such that a substantial portion of the opening prior to deposition of the layer remains unfilled after deposition of the layer. In some embodiments, the liner may be formed along the entire sidewalls and lower surface of the opening. The liner may also be formed on a planar surface of a planar substrate.

[0028] As used herein, "atomic layer deposition" or "cyclic deposition" refers to the sequential exposure of two or more reactive compounds to deposit layers of material on a substrate surface. The substrate or portions of the substrate surface are separately exposed to the two or more reactive compounds introduced into a reaction zone of a 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 and / or react on the substrate surface and then be purged from the processing chamber. The reactive compounds are said to be exposed to the substrate sequentially. In a spatial ALD process, different portions of the substrate surface or materials on the substrate surface are exposed to the two or more reactive compounds simultaneously, such that any given point on the substrate is not substantially simultaneously exposed to more than one reactive compound. As used in this specification and the appended claims, as will be understood by those skilled in the art, the term "substantially" as used in this context means that there is a possibility that a small portion of the substrate may be exposed to multiple reactive gases simultaneously due to diffusion, and that such simultaneous exposure is not intentional.

[0029] 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 region, followed by a first time delay. Next, a second precursor or compound B is pulsed into the reaction region, followed by a second delay. During each time delay, a purge gas, such as argon, is introduced into the process chamber to purge the reaction region or remove any residual reactive compounds or reaction byproducts from the reaction region. Alternatively, the purge gas may flow continuously during the entire deposition process, such that only the purge gas flows during the time delay between pulses of the reactive compounds. The reactive compounds are either pulsed until a desired film or film thickness is formed on the substrate surface. In either scenario, pulsing compound A, purge gas, compound B, and purge gas of the ALD process is a cycle. A cycle can begin with either compound A or compound B and continue in that order until a film having a predetermined thickness is achieved.

[0030] In an embodiment of a spatial ALD process, a first reactant gas and a second reactant gas (e.g., nitrogen) are delivered simultaneously to the reaction region but separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas delivery apparatus such that any given point on the substrate is exposed to both the first and second reactant gases.

[0031] In one or more embodiments, the liner and / or film is conformally deposited on the surface. As used herein, the term "conformal" or "conformally" refers to a film that adheres to and uniformly covers an exposed surface with a thickness that varies less than 5%, less than 2%, or less than 1% relative to the average thickness of the film. For example, Thick films can have less than The thickness variation includes at least the edges, corners, sides, and bottom of the recess. For example, the conformal films deposited by ALD in various embodiments of the present disclosure provide coverage of the deposited area with substantially uniform thickness on complex surfaces.

[0032]

[0014] Embodiments of the present disclosure advantageously provide methods for improving the resistivity of a molybdenum film deposited on an underlying molybdenum layer (eg, a molybdenum-containing liner) formed by the methods described herein.

[0033] Resistivity is a property of a material and a measure of its resistance to the movement of electrical charge through it. A material's resistivity affects the electrical operation of integrated circuits. Low-resistivity molybdenum films minimize power loss and overheating in integrated circuit designs. Because the resistivity of the liner layer is typically greater than that of the bulk material, the thickness of the liner layer should be minimized to keep the overall resistivity as low as possible. On the other hand, the molybdenum-containing liner should be thick enough to completely cover the underlying substrate to support high-quality bulk deposition.

[0034] In addition to providing molybdenum-containing films with low resistivity, the methods described herein provide films with good conformability and adhesion to underlying materials. One or more embodiments provide methods in which a molybdenum-containing liner is deposited directly on a dielectric surface. The inventors have unexpectedly discovered that a unique combination of a molybdenum-containing precursor and an organosilane reducing agent allows for molybdenum deposition on dielectric surfaces. Further embodiments advantageously provide methods for reducing stack resistivity for bottom-up gapfill of vias with improved molybdenum film properties.

[0035] It is known that hydrogen (H 2 ) can reduce metal chlorides (such as molybdenum (Mo) or tungsten (W)) to metals at higher temperatures, such as temperatures greater than 475° C. However, the use of hydrogen (H 2 ) to reduce metal chlorides (such as molybdenum (Mo) or tungsten (W)) to metals at lower temperatures (such as temperatures less than 400° C.) is thermodynamically / kinetically unfavorable.

[0036] One or more embodiments relate to a method for depositing a molybdenum film at a low temperature. The atomic layer deposition (ALD) process of one or more embodiments is a thermal process and does not involve the use of plasma. In one or more embodiments, the deposited film may be treated with plasma. Without being limited by theory, it is contemplated that depositing a molybdenum film directly on a substrate surface (such as a dielectric layer) using plasma will modify the composition of the dielectric layer. In some embodiments, the method described herein advantageously includes depositing a molybdenum film at a low temperature while minimizing the composition modification of the underlying layer (such as a dielectric layer). In some embodiments, this method advantageously includes, as an example, depositing a molybdenum film for contacts & multi-level interconnects at a temperature of less than or equal to 400°C. The molybdenum film may be deposited at a temperature in the range of 250°C to 400°C and a pressure in the range of 1 Torr to 300 Torr, such as a pressure in the range of 10 Torr to 100 Torr, or a pressure of about 35 Torr. Without being limited by theory, it is contemplated that low temperature deposition maintains the properties of the low-K dielectric material, and trenches and vias are patterned in the low-K dielectric material.

[0037] It is also expected that high deposition temperatures, such as temperatures greater than 400°C or greater than 450°C, will cause mechanical deformation of the low-K dielectric material, higher diffusion of faster and higher metal atoms or byproducts (HF, HCl, etc.) into the low-κ dielectric material, which changes the κ value, breakdown voltage and increases resistance-capacitance (RC) delay.

[0038] Further embodiments of the present disclosure are illustrated by the accompanying drawings, which illustrate devices (e.g., transistors) and processes for forming transistors according to one or more embodiments of the present disclosure. The processes shown are merely illustrative of possible uses for the disclosed processes, and skilled artisans will recognize that the disclosed processes are not limited to the illustrated applications.

[0039] Figure 1 A process flow diagram is illustrated for method 10. In some embodiments, method 10 includes depositing a molybdenum film (e.g., a first molybdenum film) directly on a substrate surface by exposing the substrate surface to a molybdenum-containing precursor and an organosilane reducing agent (operation 12); treating the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film (operation 14); and, optionally, depositing a second molybdenum film on the substantially carbon-free first molybdenum film (operation 16).

[0040] In some embodiments, at operation 12, depositing the first molybdenum film comprises one or more of atomic layer deposition (ALD), chemical vapor deposition (CVD), or pulsed CVD (pCVD). In some embodiments, at operation 12, the first molybdenum film is conformally deposited directly on the substrate surface. The atomic layer deposition (ALD) process of one or more embodiments is a thermal process and does not involve the use of plasma. In one or more embodiments, the deposited film can be treated with plasma. In some embodiments, the substrate surface is exposed to a molybdenum-containing precursor and an organosilane reducing agent simultaneously. In some embodiments, the substrate surface is exposed to a molybdenum-containing precursor and an organosilane reducing agent sequentially.

[0041] In some embodiments, at operation 12, depositing the first molybdenum film includes atomic layer deposition (ALD), which includes exposing the substrate surface to one or more cycles of a first precursor (e.g., a molybdenum-containing precursor), a purge gas, a second precursor (e.g., an organosilane reducing agent), and a purge gas.

[0042] In some embodiments, at operation 12, depositing the first molybdenum film comprises a spatial ALD process in which a first reactant gas (e.g., a molybdenum-containing precursor) and a second reactant gas (e.g., an organosilane reducing agent) are delivered simultaneously to the reaction region but separated by an inert gas curtain and / or a vacuum curtain. In some embodiments, at operation 12, depositing the first molybdenum film comprises co-flowing the molybdenum-containing precursor and the organosilane reducing agent. In some embodiments, at operation 12, depositing the first molybdenum film comprises chemical vapor deposition (CVD). In some embodiments, at operation 12, depositing the first molybdenum film comprises pulsed chemical vapor deposition (pCVD), in which one or both of the reactants (e.g., a molybdenum-containing precursor and an organosilane reducing agent) are pulsed into the processing chamber.

[0043] Advantageously, in one or more embodiments, the molybdenum films described herein are deposited in a manner that avoids gas phase reactions in a reactor (processing chamber) at a temperature of 400° C. or less. Without wishing to be bound by theory, it is contemplated that avoiding gas phase reactions during deposition results in the formation of films with improved conformality and improved film properties. Gas phase reactions of the molybdenum-containing precursor and the organosilane reducing agent can be avoided by implementing a dual-channel showerhead comprising a first channel and a second channel, wherein the molybdenum-containing precursor flows through the first channel and the organosilane reducing agent flows through the second channel, or vice versa. In some embodiments, the molybdenum-containing precursor and the organosilane reducing agent are symmetrically distributed near the wafer (or substrate) to avoid gas phase reactions. In some embodiments, gas phase reactions can be avoided by depositing the molybdenum film using a spatial ALD process, wherein a first reactant gas (e.g., a molybdenum-containing precursor) and a second reactant gas (e.g., an organosilane reducing agent) are delivered simultaneously to the processing region but separated by an inert gas curtain and / or a vacuum curtain.

[0044] The molybdenum-containing precursor may include any suitable molybdenum-containing compound. In some embodiments, the molybdenum-containing precursor includes any suitable molybdenum halide precursor. In some embodiments, the molybdenum-containing precursor includes one or more of molybdenum pentachloride (MoCl5), molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxytetrachloride (MoOCl4), molybdenum hexafluoride (MoF6), molybdenum hexacarbonyl, bis(tertiary butylimino)-bis(dimethylamino)molybdenum, or bis(ethylphenyl)molybdenum.

[0045] The organosilane reducing agent includes a compound of formula (II) or formula (III)

[0046]

[0047] where R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R a 、R b 、R c 、R d 、R e and R f are independently selected from hydrogen (H), substituted alkyl or unsubstituted alkyl; and X, Y, X' and Y' are independently selected from nitrogen (N) and carbon (C).

[0048] As used herein, the terms "lower alkyl," "alkyl," or "alk," alone or as part of another group, include both straight and branched chain hydrocarbons containing from 1 to 20 carbons in a regular chain, such as methyl, ethyl, propyl, isopropyl, butyl, tert-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethyl-pentyl, nonyl, decyl, undecyl, dodecyl, various branched chain isomers of the foregoing, and the like. Such groups may optionally include up to 1 to 4 substituents. Alkyl groups may be substituted or unsubstituted. In particular embodiments, R a 、R b 、R c 、R d 、R e and R f In some embodiments, at least one of R a 、R b 、R c 、R d 、R e and R f Each of includes a methyl group.

[0049] In one or more embodiments, the organosilane reducing agent is selected from bis(trimethylsilyl)cyclohexadiene, bis(trimethylsilyl)diaza-cyclohexadiene, bis(trimethylsilyl)aza-cyclohexadiene, 3,6-bis(trimethylsilyl)-1,4-cyclohexadiene, 1-methyl-3,6-bis(trimethylsilyl)-1,4-cyclohexadiene, and 1,4-bis-(trimethylsilyl)-1,4-diaza-2,5-cyclohexadiene. In some embodiments, the organosilane reducing agent includes 1,4-bis(trimethylsilyl)-2-methyl-2,5-cyclohexadiene.

[0050] In one or more embodiments, a molybdenum-containing precursor is delivered to the substrate from a first ampoule and an organosilane reducing agent is delivered to the substrate from a second ampoule. In some embodiments, the first ampoule and / or the second ampoule are maintained at a temperature in the range of about 30°C to about 150°C, including a range of about 50°C to about 100°C. In one or more specific embodiments, a molybdenum film (e.g., the molybdenum films 406 / 408 / 506 / 508 described herein) can be deposited at a temperature in the range of 250°C to 400°C and a pressure of about 35 Torr, wherein the first ampoule delivering the molybdenum-containing precursor is maintained at a temperature of about 60°C and the second ampoule delivering the organosilane reducing agent is maintained at a temperature of about 65°C.

[0051] The molybdenum film formed by the methods described herein can be substantially free of impurities. In one or more embodiments, the molybdenum film is substantially free of carbon (C) despite the substrate being exposed to a carbon-containing organosilane reducing agent. One or more embodiments of the present disclosure relate to operation 14 of method 10, which includes treating the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film. As used herein, the term "substantially carbon-free" means that on an atomic percentage (at.%) basis, less than about 5%, including less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5%, and less than about 0.1% of the total composition of the molybdenum film contains carbon.

[0052] In one or more embodiments, the organosilane reducing agent comprises a compound of formula (II) or (III) and one or more of X, Y, X′ or Y′ comprises nitrogen (N). In one or more embodiments, the molybdenum film is substantially free of nitrogen (N) despite exposure of the substrate to the nitrogen-containing organosilane reducing agent. One or more embodiments of the present disclosure relate to operation 14 of method 10, which comprises treating the molybdenum film with a plasma to remove nitrogen and form a molybdenum film that is substantially free of nitrogen. As used herein, the term “substantially free of nitrogen” means that on an atomic percentage (at.%) basis, less than about 5% of the total composition of the molybdenum film comprises nitrogen, including less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5%, and less than about 0.1%.

[0053] In one or more embodiments, the molybdenum film contains greater than about 90% total molybdenum content on an atomic basis, including greater than about 95% total molybdenum, greater than about 96% total molybdenum, greater than about 97% total molybdenum, greater than about 98% total molybdenum, or greater than about 99% total molybdenum. As used herein, the term "total metal content" refers to the percentage of molybdenum present in the molybdenum film on an atomic basis. In one or more embodiments, the molybdenum may be derived from a molybdenum-containing precursor.

[0054] In this description, the molybdenum film deposited directly on the substrate surface may be plasma treated at operation 14. The plasma may comprise any suitable plasma known to those skilled in the art. In some embodiments, the plasma may be composed of hydrogen (H2), nitrogen (N2), or silane (Si x H y ) is formed by one or more of the following. The plasma may include hydrogen (H2) ions and / or radicals, nitrogen (N2) ions or silane (Si x H y ) ions and / or radicals. The plasma may be an in-situ plasma or an ex-situ plasma. In some embodiments, the plasma is an ex-situ plasma formed of hydrogen (H 2 ) ions. It has been advantageously found that in certain embodiments where the plasma is an ex-situ plasma formed of hydrogen (H 2 ) ions, the deposited molybdenum film has a reduced resistivity compared to a molybdenum film treated with a plasma formed of hydrogen (H 2 ) radicals.

[0055] The plasma can be generated by any suitable plasma source known to the skilled person. In some embodiments, the plasma is generated by a plasma source selected from one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source.

[0056] In one or more embodiments, an ion filter separates one or more plasma sources. In one or more embodiments, the ion filter is used to filter ions from the plasma effluent during transport from the plasma source to the substrate surface. In one or more embodiments, the ion filter acts to reduce or eliminate ionic charged species that travel from the plasma source to the substrate surface. In one or more embodiments, uncharged neutral and radical species can travel through at least one aperture in the ion filter to react at the substrate surface. It should be noted that completely eliminating ionic charged species surrounding the substrate surface is not always a desired goal. In one or more embodiments, ionic species are required to reach the substrate surface to perform etching and / or deposition processes. In these examples, the ion filter helps control the concentration of ionic species in the area surrounding the substrate surface to a level that facilitates processing / cleaning and / or deposition processes. Without wishing to be bound by theory, it is contemplated that the use of the ion filter can improve the conformality of the deposited molybdenum film. In one or more embodiments, the ion filter comprises a showerhead. In some embodiments, the showerhead is a dual-channel showerhead, such as the dual-channel showerhead described herein.

[0057] In some embodiments, at operation 16, a second molybdenum film is deposited on the plasma-treated first molybdenum film. In one or more embodiments, the second molybdenum film is formed by the same treatment of the first molybdenum film as at operation 12. In some embodiments, the second molybdenum film is formed by exposing the first molybdenum film that was plasma-treated at operation 14 to a molybdenum-containing precursor and an organosilane reducing agent. In some embodiments, the second molybdenum film is formed by exposing the first molybdenum film that was plasma-treated at operation 14 to a plasma containing a molybdenum precursor and a reducing agent. The plasma may comprise any suitable plasma known to those skilled in the art. In some embodiments, the plasma is composed of hydrogen (H2), nitrogen (N2), or silane (Si x H y ). The plasma may be generated by any suitable plasma source known to those skilled in the art. In some embodiments, the plasma is generated by a plasma source selected from one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source.

[0058] Advantageously, in one or more embodiments, the molybdenum films described herein are deposited in a manner that avoids gas phase reactions in a reactor (processing chamber) at a temperature of 400° C. or less. A molybdenum-containing precursor is reacted with a plasma formed from a reducing agent, such as hydrogen (H 2 ), nitrogen (N 2 ), or silane (Si x H yGas-phase reactions (e.g., plasma formed from one or more of the molybdenum precursors) can be avoided by implementing a dual-channel showerhead comprising a first channel and a second channel, wherein the molybdenum-containing precursor flows through the first channel and the plasma formed from the reducing agent flows through the second channel, or vice versa. In some embodiments, the molybdenum-containing precursor and the plasma formed from the reducing agent are symmetrically distributed near the wafer (or substrate) to avoid gas-phase reactions. In some embodiments, gas-phase reactions can be avoided by depositing molybdenum films using a spatial ALD process, wherein a first reactant gas (e.g., a molybdenum-containing precursor) and a second reactant gas (e.g., a plasma formed from the reducing agent) are delivered to the reaction region simultaneously but separated by an inert gas curtain and / or a vacuum curtain.

[0059] Figure 2 A cross-sectional isometric view of a processing chamber is illustrated in accordance with one or more embodiments. Figure 3 A cross-sectional view of a processing chamber according to one or more embodiments is illustrated. Figure 2 and Figure 3 The processing chamber in will be further described later.

[0060] Figures 4A to 4C Depicts a cross-sectional view of a deposition process on a substrate that produces a low-resistance molybdenum film on a dielectric layer according to one or more embodiments. Figure 4A , shows a substrate 402 having a surface such as a top surface 403 and a dielectric layer 404 on the top surface 403. Figure 4B In one or more embodiments, a first molybdenum film 406 (eg, a molybdenum-containing liner 406 ) is shown directly on the dielectric layer 404 on the top surface 403 of the substrate 402 . Figure 4C In one or more embodiments, a molybdenum film 408 is shown on the molybdenum-containing liner 406 .

[0061] The substrate 402 can be any suitable substrate material. In one or more embodiments, the substrate 402 comprises a semiconductor material such as silicon (Si), carbon (C), germanium (Ge), silicon germanium (SiGe), gallium arsenide (GaAs), indium phosphide (InP), indium gallium arsenide (InGaAs), indium aluminum arsenide (InAlAs), germanium (Ge), silicon germanium (SiGe), other semiconductor materials, or any combination thereof. In one or more embodiments, the substrate 402 comprises one or more of silicon (Si), germanium (Ge), gallium (Ga), arsenic (As), indium (In), phosphorus (P), or selenium (Se). In some embodiments, the substrate 402 comprises one or more of titanium nitride (TiN), titanium silicide (TiSi), tungsten-titanium silicide alloy, clean silicon (Si), boron-doped silicon germanium (SiGeB), clean silicon phosphide (SiP), titanium aluminum (TiAl), ruthenium (Ru), tungsten (W), and molybdenum (Mo). While a few examples of materials from which substrate 402 may be made have been provided, any material that can serve as the basis for passive and active electronic devices (e.g., transistors, memories, capacitors, inductors, resistors, switches, integrated circuits, amplifiers, optoelectronic devices, or any other electronic device) may be utilized.

[0062] In some embodiments, substrate 402 may include a dielectric material, such as a silicon-containing dielectric material and / or a metal oxide dielectric material. In some embodiments, substrate 402 may include one or more dielectric surfaces (such as dielectric layer 404) comprising a low-κ dielectric material such as, but not limited to, silicon oxide (SiOx), silicon sub-oxide, silicon nitride (SiN x ), silicon nitride (Si3N4), silicon carbide (SiC x ), silicon oxycarbide (SiO x C y ), silicon carbide nitride (SiC x N y ), silicon oxynitride (SiO x N y ), tantalum nitride (TaN), hafnium oxide (HfO x ) or a combination thereof.

[0063] refer to Figure 4B, a first molybdenum film 406 is formed on the substrate 402, such as on the dielectric layer 404. In one or more embodiments, the first molybdenum film 406 is formed by operation 12 of the method 10 described above. In one or more embodiments, the first molybdenum film 406 described herein refers to a molybdenum-containing liner 406. In an embodiment in which a molybdenum-containing liner 406 is present, the molybdenum-containing liner 406 is formed by one or more of atomic layer deposition (ALD), chemical vapor deposition (CVD), or pulsed CVD (pCVD). The atomic layer deposition (ALD) process of one or more embodiments is a thermal process and does not involve the use of plasma. In one or more embodiments, the deposited film is treated with plasma. In an embodiment in which a molybdenum-containing liner 406 is present, the molybdenum-containing liner 406 is formed by operation 12, such as by exposing the dielectric layer 404 to a molybdenum-containing precursor and an organosilane reducing agent. In one or more embodiments, the molybdenum-containing liner 406 is conformally deposited on the dielectric layer 404.

[0064] The molybdenum-containing liner 406 may have any suitable thickness. In some embodiments, the molybdenum-containing liner 406 has a thickness less than or equal to Including, for example, thickness in the range of to to to to to to to or to

[0065] In one or more embodiments, the second molybdenum film 408 is deposited directly on the molybdenum-containing liner 406. The second molybdenum film 408 can have any suitable thickness. As described herein, in some embodiments, the first molybdenum film 406 can be referred to as the molybdenum-containing liner 406 and the second molybdenum film 408 can be referred to as the molybdenum film 408. The second molybdenum film 408 can be formed by the same process as the molybdenum-containing liner 406 (e.g., operation 12).

[0066] In embodiments where a molybdenum-containing liner 406 is present, a second molybdenum film 408 is formed by operation 16 , such as by exposing the molybdenum-containing liner 406 plasma-treated in operation 14 to a molybdenum-containing precursor and an organosilane reducing agent.

[0067] In some embodiments, the second molybdenum film 408 is formed by exposing the molybdenum-containing liner 406, which was plasma-treated in operation 14, to a plasma formed from a molybdenum-containing precursor and a reducing agent. The plasma may include any suitable plasma known to those skilled in the art. In some embodiments, the plasma is composed of hydrogen (H2), nitrogen (N2), or silane (Si x H y). The plasma may be generated by any suitable plasma source known to those skilled in the art. In some embodiments, the plasma is generated by a plasma source selected from one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source.

[0068] Advantageously, the molybdenum film 408 on the molybdenum-containing liner 406 has a resistivity that is at least 30% lower than that of the titanium nitride (TiN) film having the conformally deposited molybdenum film deposited thereon. In some embodiments, when the conformally deposited molybdenum-containing liner 406 and the molybdenum film 408 have a combined thickness of about When the conformally deposited molybdenum-containing liner 406 and the molybdenum film 408 define a film stack having a resistivity of less than or equal to 35 μΩ-cm. It has been advantageously discovered that using the methods described herein (which include using a plasma such as hydrogen (H2) radicals) to treat the conformally deposited molybdenum-containing liner 406 and / or molybdenum film 408, impurities can be removed more efficiently, which can further increase the film grain size and reduce the resistivity. In some embodiments, when the conformally deposited molybdenum-containing liner 406 and the molybdenum film 408 have a combined thickness of about When the resistivity of this film stack is in the range of 15 μΩ-cm to 35 μΩ-cm, including in the range of 20 μΩ-cm to 35 μΩ-cm, in the range of 25 μΩ-cm to 35 μΩ-cm, in the range of 20 μΩ-cm to 25 μΩ-cm, or in the range of 30 μΩ-cm to 35 μΩ-cm. In some embodiments, when the conformally deposited molybdenum-containing liner 406 and the molybdenum film 408 have a combined thickness of about When , the resistivity of this film stack is about 31 μΩ-cm.

[0069] Another aspect of the present disclosure relates to an electronic device comprising a conformally deposited molybdenum-containing liner (e.g., a first molybdenum film) on a dielectric surface and a molybdenum film (e.g., a second molybdenum film) directly on the molybdenum-containing liner. The inventive method can be utilized at any device node, but can be particularly advantageous at device nodes of about 25 nm or less, such as about 5 nm to about 25 nm.

[0070] A further aspect of the present disclosure relates to a method that is part of a gapfill process. In some embodiments, a molybdenum-containing liner is deposited on a dielectric surface of one or more high-aspect-ratio gap features, the high-aspect-ratio gap features including vertical gap features and / or horizontal gap features, and the molybdenum in the gap features forms a horizontal interconnect through which current flows. Without wishing to be bound by theory, according to one or more embodiments of the method described herein, gaps filled with molybdenum conformally deposited on the molybdenum-containing liner result in improved electrical operation of the integrated circuit by minimizing power loss and overheating in the integrated circuit having the molybdenum-filled gaps.

[0071] refer to Figures 5A to 5C , with respect to a feature 500 defining a trench, a method of filling a feature formed on a top surface 503 of a substrate 502 is shown, the trench having both a top surface 503, a bottom surface 530, and a gap defined by opposing sidewalls 520. The substrate 502 may include any upper surface with respect to Figures 4A to 4C The substrate 402 is not limited to a material. Figures 4A to 4C In the embodiment shown in , substrate 402 includes a dielectric region.

[0072] In one or more embodiments, reference Figure 5B The method of filling a feature includes conformally depositing a molybdenum-containing liner 506 directly on a dielectric region including a top surface 503 within a feature 500 on a surface of a substrate 502. The feature 500 includes at least one surface defining a trench, the trench including a top surface 503, a bottom surface 530, and two opposing sidewalls 520 containing a dielectric. In one or more embodiments, the molybdenum-containing liner 506 is conformally deposited directly on the dielectric region by operation 12.

[0073] refer to Figure 5C , the method includes depositing a molybdenum film 508 on a conformally deposited molybdenum-containing liner 506 to fill the feature 500, the molybdenum film 508 being substantially free of gaps or voids. In some embodiments, the molybdenum film 508 is deposited directly on the conformally deposited molybdenum-containing liner 506 to fill the feature 500 by operation 16, such as by one or more of atomic layer deposition (ALD), chemical vapor deposition (CVD), or pulsed CVD (pCVD), exposing the surface of the molybdenum-containing liner 506 to a molybdenum-containing precursor and an organosilane reducing agent. The atomic layer deposition (ALD) process of one or more embodiments is a thermal process and does not involve the use of plasma. The surface of the molybdenum-containing liner 506 may be exposed to, for example, one or more ALD cycles, including exposing the surface of the molybdenum-containing liner 506 to a first precursor (e.g., a molybdenum-containing precursor), a purge gas, a second precursor (e.g., an organosilane reducing agent), and a purge gas to form the molybdenum film 508 to a desired thickness to fill the feature 500.

[0074] In some embodiments, a molybdenum film 508 is formed in operation 16 by exposing the molybdenum-containing liner 506, which was plasma-treated in operation 14, to a plasma formed from a molybdenum-containing precursor and a reducing agent. The plasma may include any suitable plasma known to those skilled in the art. In some embodiments, the plasma is composed of hydrogen (H2), nitrogen (N2), or silane (Si x H y). The plasma may be generated by any suitable plasma source known to those skilled in the art. In some embodiments, the plasma is generated by a plasma source selected from one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source.

[0075] In one or more specific embodiments, when the molybdenum-containing precursor includes molybdenum hexafluoride (MoF6), the plasma does not include hydrogen (H2). It is contemplated that when the molybdenum-containing precursor includes molybdenum hexafluoride (MoF6) and the plasma includes hydrogen (H2), the reactants can be used to thermally deposit molybdenum films at temperatures greater than or equal to 400°C, but this reaction produces significant amounts of hydrofluoric acid (HF), which can have a deleterious effect on the underlying low-κ dielectric material.

[0076] The figures show a substrate 502 having a single feature 500 for illustrative purposes; however, those skilled in the art will appreciate that there may be more than one feature 500. The shape of the feature 500 may be any suitable shape, including, but not limited to, a trench and a cylindrical through-hole. When used in this manner, the term "feature" refers to any intentional surface irregularity. Suitable examples of features include, but are not limited to, trenches having a top surface, a bottom surface, and two opposing sidewalls comprising a dielectric material; spikes having a top and two sidewalls extending upward from the surface; and through-holes having sidewalls extending downward from the surface and a bottom. In some embodiments, the bottom of the through-hole comprises an open bottom defined or bounded by an underlying material, such as a dielectric material that also defines the two sidewalls, or the underlying material at the bottom may be a conductor such as a metal (e.g., copper), which may be a different material. In one or more embodiments, at least one feature 500 comprises one or more of a trench or a through-hole. In a particular embodiment, at least one feature 500 comprises a trench. In further embodiments, the terms "at least one feature 500" and "trench 500" may be used interchangeably. Trench 500 has a depth to a bottom surface 530 and a width between two opposing sidewalls 520. In some embodiments, the depth is in a range of 2 nm to 200 nm, 3 nm to 200 nm, 5 nm to 100 nm, 2 nm to 100 nm, or 50 nm to 100 nm. In some embodiments, the width is in a range of 10 nm to 100 nm, 10 nm to 20 nm, 10 nm to 50 nm, or 50 nm to 100 nm. In some embodiments, trench 500 has an aspect ratio (depth / width) in a range of 1:1 to 20:1, 5:1 to 20:1, 10:1 to 20:1, or 15:1 to 20:1.

[0077] In some embodiments, the molybdenum film 508 is laterally bounded by two opposing sidewalls 520 of at least one feature 500. When used in this manner, "laterally bounded" means that the deposited material does not extend beyond the intersection between the top surface 502 and the two opposing sidewalls 520. In some embodiments, the molybdenum film 508 extends beyond the at least one feature 500. In some embodiments, the molybdenum film 508 fills the trench 500. When used in this manner, a film that "fills the trench" has a volume that occupies at least 95%, at least 98%, or at least 99% of the volume of the trench 500. In some embodiments, the molybdenum film 508 filling the trench 500 has a fill height in the range of 30 nm to 75 nm, including in the range of 40 nm to 60 nm.

[0078] Embodiments of the present disclosure advantageously provide a molybdenum film 508 having a reduced resistivity compared to molybdenum films deposited by processes other than those described herein. Embodiments of the present disclosure advantageously provide a molybdenum film 508 that is free of voids and seams or substantially free of voids and seams. As used in this manner, "substantially free" means that on an atomic basis, less than about 5%, including less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5%, and less than about 0.1% of the total composition of the conformally deposited molybdenum film 508 comprises voids and / or seams.

[0079] The methods described herein may be performed in any suitable process chamber known to a skilled artisan. The methods described herein may be performed in, for example, an atomic layer deposition (ALD) process chamber (including a spatial ALD process chamber), a chemical vapor deposition (CVD) process chamber, or a pulsed CVD (pCVD) process chamber. The process chamber or process chamber platform may include, but is not limited to: Tesseract TM 、 system and any related PRODUCER platform, system, and / or Selectra TM etch chambers, all available from Applied Materials, Inc., Santa Clara, California. In some embodiments, the processing chamber includes a Selectra TM An etch chamber includes a plasma generating source and a molybdenum precursor source for flowing a molybdenum-containing precursor. In some embodiments, the entire processing chamber or portions of the processing chamber are coated with nickel to reduce undesirable particle formation.

[0080] In one or more embodiments, a processing chamber includes a pedestal. The pedestal includes a heater and an electrostatic chuck. In some embodiments, the pedestal includes a high current electrostatic chuck operating at a temperature in the range of about 200° C. to about 550° C., including a range of about 200° C. to about 300° C. In one or more embodiments, the pedestal supports a substrate within the processing chamber.

[0081] In one or more embodiments, a molybdenum-containing precursor is delivered to a processing chamber from a first ampoule and an organosilane reducing agent is delivered to the processing chamber from a second ampoule. In some embodiments, the first ampoule and / or the second ampoule are maintained at a temperature in the range of about 30°C to about 150°C, including a range of about 50°C to about 100°C. In one or more specific embodiments, a molybdenum film (e.g., molybdenum film 406 / 408 / 506 / 508) can be deposited at a temperature in the range of 250°C to 400°C and a pressure of about 35 Torr, wherein the first ampoule delivering the molybdenum-containing precursor is maintained at a temperature of about 60°C and the second ampoule delivering the organosilane reducing agent is maintained at a temperature of about 65°C.

[0082] In some embodiments, portions of the processing chamber and / or substrate are coated with molybdenum prior to exposing the molybdenum-coated portions to the plasma.

[0083] The present disclosure provides methods for use in single wafer or multi-wafer (also referred to as batch) processing chambers. Figure 2 and Figure 3 A processing chamber 100 according to one or more embodiments of the present disclosure is illustrated. Figure 2 The processing chamber 100 is shown illustrated as a cross-sectional isometric view. Figure 3 The processing chamber 100 is shown in cross-section. Accordingly, some embodiments of the present disclosure are directed to a processing chamber 100 incorporating a substrate support 200.

[0084] The processing chamber 100 has a housing 102 with walls 104 and a bottom 106. The housing 102 and the top plate 300 define a processing volume 109, also referred to as an interior volume. In some embodiments, portions of the processing volume 109 or the entire processing volume 109 is coated with nickel to reduce undesirable particle formation. In some embodiments, the processing chamber 100 includes a plasma source (not shown) on the top plate 300. In some embodiments, the plasma source includes one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source. In some embodiments, the processing chamber includes a Selectra TM The etch chamber includes a plasma generating source (not shown) and a molybdenum precursor source on a top plate 300 for flowing a molybdenum-containing precursor.

[0085] The illustrated processing chamber 100 includes a plurality of processing stations 110. The processing stations 110 are located within the interior volume 109 of the housing 102 and are positioned in an annular arrangement around the rotational axis 211 of the substrate support 200. Each processing station 110 includes a gas distribution plate 112 (also referred to as a gas injector) having a front surface 114. In some embodiments, the front surface 114 of each of the gas injectors 112 is substantially coplanar. The processing stations 110 are defined as areas in which processing can occur. For example, in some embodiments, the processing stations 110 are defined as areas bounded by a support surface 231 of the substrate support 200 (described below) and the front surfaces 114 of the gas injectors 112. In the illustrated embodiment, a heater 230 serves as a substrate support surface and forms a portion of the substrate support 200.

[0086] The processing station 110 can be configured to perform any suitable process and provide any suitable processing conditions. The type of gas distribution plate 112 used will depend, for example, on the type of process being performed and the type of showerhead or gas injector. For example, a processing station 110 configured to operate as an atomic layer deposition apparatus may have a showerhead or a vortex-type gas injector. In some embodiments, the processing station 110 includes a dual-channel showerhead as described herein. In some embodiments, portions of the dual-channel showerhead or the entire dual-channel showerhead is coated with nickel to reduce undesirable particle formation. A processing station 110 configured to operate as a plasma station may have one or more electrodes and / or ground plate configurations to generate a plasma while allowing the plasma gas to flow toward the wafer. Figure 3 The embodiment illustrated in FIG has different types of processing stations 110 on the left side of the figure (processing station 110a) and on the right side of the figure (processing station 110b). Suitable processing stations 110 include, but are not limited to, thermal processing stations, microwave plasma, three-electrode CCP, ICP, parallel plate CCP, UV exposure, laser processing, pumping chambers, annealing stations, and measurement stations.

[0087] In some embodiments, the operations of the methods described herein are each performed within the same processing chamber. In some embodiments, the operations of the methods described herein are each performed within different processing chambers. In some embodiments, the different processing chambers are connected as part of a processing system. In some embodiments, the operations of the methods described herein are performed without an intervening vacuum break.

[0088] In some embodiments, one or more operations of the methods described herein are performed in situ without breaking vacuum. In some embodiments, one or more operations of the methods described herein are performed ex situ.

[0089] As used herein, the term “in situ” means that the operations of the methods described herein are each performed in the same processing chamber or in different processing chambers connected as part of a processing system such that each of the operations of the methods described herein is performed without an intervening vacuum break.

[0090] As used herein, the term “ex situ” means that the operations of the methods described herein are each performed in the same processing chamber or in different processing chambers such that one or more operations of the methods described herein are performed with an intervening vacuum break.

[0091] One or more embodiments of the present disclosure are directed to a non-transitory computer-readable medium comprising instructions that, when executed by a controller of a processing chamber, cause the processing chamber to perform the methods described herein. In some embodiments, the non-transitory computer-readable medium comprises instructions that, when executed by a controller of the processing chamber, cause the processing chamber to perform method 10.

[0092] In some embodiments, the non-transitory computer-readable medium includes instructions that, when executed by a controller of a processing chamber, cause the processing chamber to: deposit a molybdenum film directly on a surface of a substrate by exposing the substrate surface to a molybdenum-containing precursor and an organosilane reducing agent at a temperature of less than or equal to 450°C, the molybdenum film having a molybdenum-carbon (Mo-C) bond; and treat the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film.

[0093] In some embodiments, the non-transitory computer-readable medium includes instructions that, when executed by a controller of a processing chamber, cause the processing chamber to: conformally deposit a first molybdenum film (e.g., a molybdenum-containing liner) directly on a feature by exposing the feature to a molybdenum-containing precursor and an organosilane reducing agent at a temperature less than or equal to 450° C., the first molybdenum film having a molybdenum-carbon (Mo-C) bond, the feature including a surface defining a trench, the trench including a top surface, a bottom surface comprising a metal material, and two opposing sidewalls comprising a low-K dielectric material; treat the first molybdenum film with a plasma to remove carbon and form a substantially carbon-free first molybdenum film; and deposit a second molybdenum film on the substantially carbon-free first molybdenum film to fill the feature.

[0094] References throughout this specification to "one embodiment," "some embodiments," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described with respect to that embodiment is included in at least one embodiment of the present disclosure. Thus, the appearance of phrases such as "in one or more embodiments," "in some embodiments," "in one embodiment," or "in an embodiment" in various places throughout this specification do not necessarily refer to the same embodiment of the present disclosure. In one or more embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner.

[0095] Although the present disclosure has been described herein with reference to specific embodiments, it will be understood that these embodiments are 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 apparatus of the present disclosure without departing from the spirit and scope of the present disclosure. Therefore, it is intended that the present disclosure include modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. A deposition method comprising: depositing a molybdenum film having a molybdenum-carbon (Mo—C) bond directly on a substrate surface by exposing the substrate surface to a molybdenum-containing precursor and an organosilane reducing agent at a temperature of 450° C. or less; and The molybdenum film is treated with a plasma to remove carbon and form a substantially carbon-free molybdenum film.

2. The deposition method of claim 1, wherein the substrate surface comprises a low-κ dielectric material.

3. The deposition method of claim 2, wherein the low-κ dielectric material comprises one or more of silicon oxide (SiOx), silicon nitride (SiN), silicon oxynitride (SiON), silicon oxycarbide (SiOC), silicon oxycarbonitride (SiOCN), or silicon carbide nitride (SiCN).

4. The deposition method of claim 1 , wherein the molybdenum-containing precursor comprises one or more of molybdenum pentachloride (MoCl 5 ), molybdenum dioxide dichloride (MoO 2 Cl 2 ), molybdenum oxytetrachloride (MoOCl 4 ), molybdenum hexafluoride (MoF 6 ), molybdenum hexacarbonyl, bis(tertiary butylimino)-bis(dimethylamino)molybdenum, or bis(ethylphenyl)molybdenum.

5. The deposition method according to claim 1, wherein the organosilane reducing agent comprises a compound of formula (II) or formula (III) where R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R a 、R b 、R c 、R d 、R e and R f are independently selected from hydrogen (H), substituted alkyl or unsubstituted alkyl; and X, Y, X' and Y' are independently selected from nitrogen (N) and carbon (C). 6 . The deposition method of claim 5 , wherein the organosilane reducing agent comprises 1,4-bis(trimethylsilyl)-2-methyl-2,5-cyclohexadiene.

7. The deposition method of claim 1, wherein depositing the molybdenum film comprises one or more of atomic layer deposition (ALD), chemical vapor deposition (CVD), or pulsed CVD (pCVD). 8 . The deposition method of claim 1 , wherein the molybdenum film is deposited at a temperature in a range of 250° C. to 400° C. and at a pressure in a range of 1 Torr to 300 Torr.

9. The deposition method of claim 1, wherein the ions are generated by a plasma source selected from one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source.

10. The deposition method according to claim 9, wherein the ions are hydrogen (H2), nitrogen (N2) or silane (Si x H y ) is formed by one or more of them.

11. The deposition method according to claim 10, wherein the plasma is an ex-situ plasma formed by hydrogen (H2) ions.

12. The deposition method of claim 1, wherein the substantially carbon-free molybdenum film comprises less than or equal to 1 at.% carbon (C).

13. A method of filling a feature formed on a surface of a substrate, the method comprising: conformally depositing a first molybdenum film having a molybdenum-carbon (Mo-C) bond directly on the feature by exposing the feature to a molybdenum-containing precursor at a temperature of less than or equal to 450° C. and an organosilane reducing agent, the first molybdenum film having a molybdenum-carbon (Mo-C) bond, the feature including a surface defining a trench, the trench including a top surface, a bottom surface, and two opposing sidewalls, the bottom surface comprising a metallic material, and the two opposing sidewalls comprising a low-κ dielectric material; treating the first molybdenum film with a plasma to remove carbon and form a substantially carbon-free first molybdenum film; as well as A second molybdenum film is deposited on the substantially carbon-free first molybdenum film to fill the feature.

14. The method of claim 13, wherein the molybdenum-containing precursor comprises one or more of molybdenum pentachloride (MoCl5), molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxytetrachloride (MoOCl4), molybdenum hexafluoride (MoF6), molybdenum hexacarbonyl, bis(tertiary butylimino)-bis(dimethylamino)molybdenum, or bis(ethylphenyl)molybdenum.

15. The method of claim 13, wherein the organosilane reducing agent comprises a compound of formula (II) or formula (III) where R 1 、R 2 、R 3 、R 4 、R 5 、R 6 、R 7 、R 8 、R a 、R b 、R c 、R d 、R e and R f are independently selected from hydrogen (H), substituted alkyl or unsubstituted alkyl; and X, Y, X' and Y' are independently selected from nitrogen (N) and carbon (C).

16. The method of claim 15, wherein the organosilane reducing agent comprises 1,4-bis(trimethylsilyl)-2-methyl-2,5-cyclohexadiene.

17. The method of claim 13, wherein the substantially carbon-free first molybdenum film comprises less than or equal to 1 at.% carbon (C).

18. The method of claim 13, wherein the ions include hydrogen (H2), nitrogen (N2), or silane (Si x H y ) and is generated by a plasma source selected from one or more of a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a microwave plasma source, or a remote plasma source.

19. The method of claim 18, wherein the ion source comprises an ion filter.

20. The method of claim 18, wherein depositing the second molybdenum film comprises exposing the substantially carbon-free first molybdenum film to the molybdenum-containing precursor and the organosilane reducing agent through a dual-channel showerhead comprising a first channel and a second channel, the molybdenum-containing precursor flowing through the first channel and the organosilane reducing agent flowing through the second channel.

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