Plasma-enhanced molybdenum deposition

Abstract

Embodiments of the present disclosure are directed to a method for depositing a molybdenum film directly onto a substrate surface (e.g., a low-k dielectric material) by exposing the substrate surface to a molybdenum-containing precursor and an organosilane reducing agent at a temperature of 450°C or less. The molybdenum-containing precursor includes one or more of molybdenum pentachloride (MoCl5), molybdenum dioxide dichloride (MoOCl2), molybdenum oxytetrachloride (MoOCl4), molybdenum hexafluoride (MoF6), molybdenum hexacarbonyl, bis(tert-butylimido)-bis(dimethylamido)molybdenum, or bis(ethylbenzene)molybdenum. The organosilane reducing agent includes a trimethylsilyl compound, such as 1,4-bis(trimethylsilyl)-2-methyl-2,5-cyclohexadiene.

Description

[Technical Field]

[0001]

[0001] Embodiments of the present disclosure relate to the field of electronic device manufacturing, and more particularly to integrated circuit (IC) manufacturing. In particular, embodiments of the present disclosure are directed to plasma-enhanced deposition of molybdenum at low temperatures. [Background technology]

[0002]

[0002] As circuit integration increases, there is an increasing need for greater uniformity and process control with respect to layer thickness. As a result, various techniques have been developed for cost-effectively depositing layers onto substrates while maintaining control over the layer's properties. Chemical vapor deposition (CVD) is one of the most common deposition processes employed to deposit layers onto substrates.

[0003] A variant of CVD that exhibits excellent step coverage is cyclic deposition or atomic layer deposition (ALD). ALD uses a chemisorption technique to sequentially deliver precursor molecules to a substrate surface. 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 as a film on the substrate surface. This ALD cycle is repeated to form a layer to a desired thickness.

[0004]

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

[0005]

[0005] Without wishing to be bound by any particular theory or principle, it is believed that molybdenum cannot be deposited and grown directly on a dielectric surface, but can be deposited and grown on a metal surface.

[0006] Molybdenum films can be used as low-resistivity electrical connections in the form of current-carrying vertical and / or horizontal interconnects, as vias between adjacent metal layers, and as contacts between a first metal layer and devices on a substrate. For example, in both blanket film and gap-fill applications, a liner film (e.g., a TiN liner film) is typically deposited on the dielectric surface to achieve reproducible 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 containing high-aspect-ratio features.

[0007]

[0007] There remains a need for improved metal liners or layers to reduce the resistivity of molybdenum films. Therefore, 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]

[0008] One or more embodiments are directed to a deposition method that includes 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 of 450°C or less, where the molybdenum film has molybdenum-carbon (Mo-C) bonds, and treating the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film.

[0009] An additional embodiment is directed to a method of filling a feature formed on a substrate surface, the method including: conformally depositing a first molybdenum film directly on the feature by exposing the feature to a molybdenum-containing precursor and an organosilane reducing agent at a temperature of 450° C. or less, the first molybdenum film having molybdenum-carbon (Mo—C) bonds, the feature including a surface defining a trench, the trench including a top surface, a bottom surface comprising a metallic 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.

[0010]

[0010] So that the features of the present disclosure may be fully understood, a more particular description of the present disclosure briefly summarized above will be obtained by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure may admit of other equally effective embodiments, and therefore the accompanying drawings illustrate only typical embodiments of the present disclosure and should not be considered as limiting the scope of the present disclosure. The embodiments 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 like elements. [Brief explanation of the drawings]

[0011] [Figure 1] 1 shows a process flow diagram of a method according to one or more embodiments. [Figure 2]

[0012] 1 illustrates a cross-sectional view of a processing chamber according to one or more embodiments. [Figure 3]

[0013] 1 illustrates a cross-sectional view of a processing chamber according to one or more embodiments. [Figure 4A]

[0014] 1 shows a schematic cross-sectional view of a dielectric layer on a substrate surface, according to one or more embodiments. [Figure 4B]

[0015] 4B shows a schematic cross-sectional view of a molybdenum-containing liner on a dielectric layer on the substrate surface shown in FIG. 4A, according to one or more embodiments. [Figure 4C]

[0016] 4C shows a schematic cross-sectional view of a molybdenum film deposited on the molybdenum liner shown in FIG. 4B, according to one or more embodiments. [Figure 5A]

[0017] 1 shows a schematic cross-sectional view of a feature on a substrate according to one or more embodiments. [Figure 5B]

[0018] 5B depicts a schematic cross-sectional view of a molybdenum-containing liner on a dielectric region of a feature on the substrate shown in FIG. 5A, according to one or more embodiments. [Figure 5C]

[0019] 5C shows a schematic cross-sectional view of a molybdenum film deposited on the molybdenum-containing liner shown in FIG. 5B, according to one or more embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0012]

[0020] Before describing some exemplary embodiments of the present disclosure, it should be understood that the present disclosure is not limited to the details of construction or process steps set forth in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways. As used herein, the term "about" means "approximately" or "nearly" and refers to a variation of no more than ±15% of a numerical value relative to a stated numerical value or range. For example, values ​​varying by ±14%, ±10%, ±5%, ±2%, or ±1% would satisfy the definition of about.

[0013]

[0021] As used herein, "substrate" refers to any substrate or any material surface formed on a substrate on which film processing is performed during a manufacturing process. For example, substrate surfaces on which processing can 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 materials, such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. In some embodiments, the substrate comprises one or more of titanium nitride (TiN), titanium silicide (TiSi), tungsten-titanium silicide alloy, cleaned silicon (Si), boron-doped silicon germanium (SiGeB), cleaned silicon phosphide (SiP), titanium aluminum (TiAl), ruthenium (Ru), tungsten (W), and molybdenum (Mo). Substrates include, but are not limited to, semiconductor wafers.

[0014]

[0022] The substrate may be subjected to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to performing film treatments directly on the surface of the substrate itself, in the present disclosure, any of the disclosed film treatment steps may be performed on an underlayer formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include such underlayers, as the context indicates. Thus, for example, if a film / layer or partial film / layer is being deposited on the substrate surface, the exposed surface of the newly deposited film / layer is the substrate surface.

[0015]

[0023] As used herein, the term "substrate surface" refers to any substrate surface on which a layer can be formed. A substrate surface can have one or more features formed thereon, one or more layers formed thereon, and combinations thereof. The shape of a feature can be any suitable shape, including, but not limited to, a peak, a trench, or a cylindrical via. The term "feature" as used in this regard refers to any intentional surface irregularity. Suitable examples of features include, but are not limited to, a trench having a top, two sidewalls, and a bottom; a peak having a top and two sidewalls extending upward from the surface; and a via having sidewalls extending downward from the surface including the bottom. In some embodiments, the bottom of the via includes an open bottom defined or bounded by an underlying material, such as a dielectric material, which may also define two sidewalls. Alternatively, the underlying material of the bottom may be a conductor, such as a metal (e.g., copper), which may be the same as or different from the sidewall material.

[0016]

[0024] As used herein and in the appended claims, the term "selectively" refers to a process that acts on a first surface to a greater extent than on another, second surface. Such a process would be described as acting "selectively" on the first surface over the second surface. The term "over" as used in this context does not refer to the physical orientation of one surface on top of the other, but rather to the relationship of the thermodynamic or kinetic properties of the chemical reactions of one surface to the other.

[0017]

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

[0018]

[0026] As used in this specification and the appended claims, the terms "precursor," "reactant," "reactive gas," and the like are used interchangeably and refer to any gas species capable of reacting with the substrate surface.

[0019]

[0027] As used herein, the term "liner" refers to a layer formed along at least a portion of the sidewalls and / or bottom 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 bottom surface of the opening. A liner may also be formed on a planar surface of a planar substrate.

[0020]

[0028] As used herein, "atomic layer deposition" or "cyclic deposition" refers to the sequential exposure of a substrate surface to two or more reactive compounds to deposit layers of material. A substrate or a portion of a substrate is separately exposed to two or more reactive compounds introduced into a reaction zone of a processing chamber. In a time-domain ALD process, exposure to each reactive compound is separated by a time delay to allow each compound to adhere to and / or react with the substrate surface and then be purged from the processing chamber. These reactive compounds are said to be sequentially exposed to the substrate. In a spatial ALD process, different portions of the substrate surface, or materials on the substrate surface, are simultaneously exposed to two or more reactive compounds, with any given point on the substrate not being substantially simultaneously exposed to multiple reactive compounds. As used herein and in the appended claims, the term "substantially" as used in this context means that, as understood by those skilled in the art, small portions of a substrate may be simultaneously exposed to multiple reactive gases due to diffusion, and simultaneous exposure is not intended.

[0021]

[0029] In one embodiment of a time-domain ALD process, a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, followed by a first time delay. Then, a second precursor or compound B is pulsed into the reaction zone, followed by a second time delay. During each time delay, a purge gas (such as argon) is introduced into the processing chamber to purge the reaction zone or otherwise remove any remaining reactive compound or reaction by-products from the reaction zone. Alternatively, a purge gas can flow continuously throughout the deposition process, such that only the purge gas flows during the time delay between pulses of reactive compound. The reactive compounds are alternately pulsed until a desired film or film thickness is formed on the substrate surface. In either scenario, the ALD process pulsing compound A, purge gas, compound B, and purge gas is one cycle. The cycle can start with either compound A or compound B, and continues in each order until a film having the desired thickness is achieved.

[0022]

[0030] In a spatial ALD process embodiment, a first reactive gas and a second reactive gas (e.g., nitrogen gas) are simultaneously supplied to a reaction zone but separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas supply system so that any given point on the substrate is exposed to both the first reactive gas and the second reactive gas.

[0023]

[0031] In one or more embodiments, the liner and / or film is conformally deposited on the surface. As used herein, the terms “conformal” or “conformally” refer to a film that adheres to and uniformly covers an exposed surface, with a thickness that varies by less than 5%, less than 2%, or less than 1% relative to the average thickness of the film. For example, a 1,000 Å thick film may have a thickness variation of less than 10 Å. This thickness and variation includes at least the edges, corners, sides, and bottom of a feature. For example, a conformal film deposited by ALD in various embodiments of the present disclosure may provide coverage over a complex surface with a substantially uniform thickness across the deposition area.

[0024]

[0032] Embodiments of the present disclosure advantageously provide a method for improving the resistivity of a molybdenum film deposited on an underlying molybdenum layer (e.g., a molybdenum-containing liner) formed by a method described herein.

[0025]

[0033] Resistivity is a material property that is a measure of a material's resistance to the movement of an electric charge through it. The resistivity of a material 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 total resistance as low as possible. On the other hand, to support high-quality bulk deposition, the molybdenum-containing liner should be thick enough to completely cover the underlying substrate.

[0026]

[0034] In addition to providing molybdenum-containing films with low resistivity, the methods described herein provide films with good uniformity and adhesion to underlying materials. One or more embodiments provide a method for depositing a molybdenum-containing liner directly onto a dielectric surface. Surprisingly, the inventors have discovered that a unique combination of a molybdenum-containing precursor and an organosilane reducing agent can deposit molybdenum onto a dielectric surface. Further embodiments advantageously present a method for reducing stack resistivity in bottom-up gap fill for vias with improved molybdenum film properties.

[0027]

[0035] It is known that hydrogen (H2) can reduce metal chlorides (such as molybdenum (Mo) or tungsten (W)) to metals at high temperatures, such as above 475°C. However, the use of hydrogen (H2) to reduce metal chlorides (such as molybdenum (Mo) or tungsten (W)) to metals is not thermodynamically / kinetically favorable at low temperatures, such as below 400°C.

[0028]

[0036] One or more embodiments are directed to a method for depositing a molybdenum film at low temperatures. The atomic layer deposition (ALD) process of one or more embodiments is a thermal process and does not involve the use of a plasma. In one or more embodiments, the deposited film may be treated with a plasma. While not intending to be bound by theory, it is believed that depositing a molybdenum film directly on a substrate surface, such as a dielectric layer, with a plasma may alter the composition of the dielectric layer. In some embodiments, the method described herein advantageously includes depositing a molybdenum film at low temperatures while minimizing compositional alteration of underlying layers, such as dielectric layers. In some embodiments, the method advantageously includes depositing a molybdenum film for contacts and multilayer interconnects at a temperature of, by way of example, 400°C or less. The molybdenum film may be deposited at a temperature in the range of 250°C to 400°C and at a pressure in the range of 1 Torr to 300 Torr (e.g., a pressure in the range of 10 Torr to 100 Torr, or a pressure of about 35 Torr). Without intending to be bound by theory, it is believed that low temperature deposition preserves the properties of the low-k dielectric material that patterns the trenches and vias.

[0029]

[0037] It is also believed that high deposition temperatures, e.g., temperatures above 400°C or even above 450°C, can result in mechanical deformation of the low-k dielectric material, faster and higher diffusion of metal atoms or by-products (HF, HCl, etc.) into the low-k dielectric material, which in turn can change the dielectric constant value, breakdown voltage, and increase the resistance-capacitor (RC) delay.

[0030]

[0038] Further embodiments of the present disclosure are illustrated by diagrams showing devices (e.g., transistors) and processes for forming the transistors, in accordance with one or more embodiments of the present disclosure. The processes shown are merely illustrative of possible uses of the disclosed processes, and one of ordinary skill in the art will recognize that the disclosed processes are not limited to the applications shown.

[0031]

[0039] 1 shows a process flow diagram of 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 (step 12), treating the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film (step 14), and optionally depositing a second molybdenum film on the substantially carbon-free first molybdenum film (step 16).

[0032]

[0040] In some embodiments, depositing the first molybdenum film in step 12 comprises one or more of atomic layer deposition (ALD), chemical vapor deposition (CVD), or pulsed CVD (pCVD). In some embodiments, in step 12, the first molybdenum film is conformally deposited directly on the substrate surface. In one or more embodiments, the atomic layer deposition (ALD) process 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. 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.

[0033]

[0041] In some embodiments, in step 12, depositing the first molybdenum film comprises atomic layer deposition (ALD), which comprises one or more cycles of exposing the substrate surface 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.

[0034]

[0042] In some embodiments, depositing the molybdenum film in step 12 comprises a spatial ALD process, in which a first reactive gas (e.g., a molybdenum-containing precursor) and a second reactive gas (e.g., an organosilane reducing agent) are simultaneously supplied to a reaction zone but separated by an inert gas curtain and / or a vacuum curtain. In some embodiments, depositing the first molybdenum film in step 12 comprises co-flowing a molybdenum-containing precursor and an organosilane reducing agent. In some embodiments, depositing the first molybdenum film in step 12 comprises chemical vapor deposition (CVD). In some embodiments, depositing the first molybdenum film in step 12 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 a processing chamber.

[0035]

[0043] Advantageously, in one or more embodiments, the molybdenum films described herein are deposited at temperatures of 400°C or less in a manner that avoids gas-phase reactions in the reactor (processing chamber). While not intending to be bound by theory, it is believed that avoiding gas-phase reactions during deposition improves conformality and results in films with enhanced film properties. Gas-phase reactions between the molybdenum-containing precursor and the organosilane reducing agent can be avoided by implementing a dual-channel showerhead including a first channel and a second channel, where the molybdenum-containing precursor is flowed through the first channel and the organosilane reducing agent is flowed 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. In this case, a first reactive gas (e.g., a molybdenum-containing precursor) and a second reactive gas (e.g., an organosilane reducing agent) are simultaneously fed into the reaction zone but separated by an inert gas curtain and / or a vacuum curtain.

[0036]

[0044] The molybdenum-containing precursor can 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 (MoOCl2), molybdenum oxytetrachloride (MoOCl4), molybdenum hexafluoride (MoF6), molybdenum hexacarbonyl, bis(tert-butylimido)-bis(dimethylamido)molybdenum, or bis(ethylbenzene)molybdenum.

[0037]

[0045] The organosilane reducing agent comprises a compound of general formula (II) or general formula (III): TIFF2026503980000002.tif86170 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).

[0038]

[0046] As used herein, the terms "lower alkyl," "alkyl," or "alk," used alone or as part of another group, include both straight-chain and branched-chain hydrocarbons typically containing 1 to 20 carbons in the chain, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethyl-pentyl, nonyl, decyl, undecyl, dodecyl, and various branched-chain isomers thereof. Such groups may optionally contain 1 to 4 substituents. Alkyl may be substituted or unsubstituted. In specific embodiments, R a , R b , R c , R d , R e , and R f At least one of R a , R b , R c , R d , R e , and R f Each of the groups contains methyl.

[0039]

[0047] 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 comprises 1,4-bis(trimethylsilyl)-2-methyl-2,5-cyclohexadiene.

[0040]

[0048] In one or more embodiments, a molybdenum-containing precursor is delivered to a substrate from a first ampoule, and an organosilane reducing agent is delivered to a substrate from a second ampoule. In some embodiments, the first ampoule and / or the second ampoule are maintained at a temperature ranging from about 30°C to about 150°C, including a range from about 50°C to about 100°C. In one or more specific embodiments, a molybdenum film (e.g., a molybdenum film 406 / 408 / 506 / 508 described herein) can be deposited at a temperature ranging from 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.

[0041]

[0049] Molybdenum films formed by the methods described herein may 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 are directed to step 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 free of carbon" means that, on an atomic percent (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 described molybdenum film contains carbon.

[0042]

[0050] In one or more embodiments, the organosilane reducing agent comprises a compound of general formula (II) or (III), wherein 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 the substrate being exposed to the nitrogen-containing organosilane reducing agent. One or more embodiments of the present disclosure are directed to step 14 of method 10, which comprises treating the molybdenum film with a plasma to remove nitrogen and form a substantially nitrogen-free molybdenum film. As used herein, the term "substantially nitrogen-free" means that, at the atomic percent (at. %) level, 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 described molybdenum film comprises nitrogen.

[0043]

[0051] In one or more embodiments, the molybdenum film comprises greater than about 90% total molybdenum at the atomic level, 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 at the atomic level. In one or more embodiments, the molybdenum may be derived from a molybdenum-containing precursor.

[0044]

[0052] As described herein, the molybdenum film deposited directly on the substrate surface may be treated with a plasma in step 14. The plasma may include any suitable plasma known to those skilled in the art. In some embodiments, the plasma may include hydrogen (H), nitrogen (N), or silane (Si). x H y The plasma is formed from one or more of hydrogen (H2) ions and / or radicals, nitrogen (N2) ions and / or radicals, or silane (Si x H yThe plasma may include one or more of hydrogen (H) 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 from hydrogen (H) ions. Advantageously, in certain embodiments where the plasma is an ex situ plasma formed from hydrogen (H) ions, it has been found that the resistivity of the deposited molybdenum film is reduced compared to molybdenum films treated with a plasma formed from hydrogen (H) radicals.

[0045]

[0053] The plasma may be generated by any suitable plasma source known to those skilled in the art, hi 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.

[0046]

[0054] 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 plasma effluents during their transit from the plasma source to the substrate surface. In one or more embodiments, the ion filter functions to reduce or remove ionic-charged species migrating from the plasma source to the substrate surface. In one or more embodiments, uncharged neutral and radical species may pass through at least one opening in the ion filter and react at the substrate surface. It should be noted that complete removal of ionic-charged species surrounding the substrate surface is not necessarily a desirable goal. In one or more embodiments, ionic species must reach the substrate surface to perform the etching and / or deposition process. In such cases, the ion filter helps control the concentration of ionic species in the region surrounding the substrate surface at a level that is conducive to the treatment / cleaning and / or deposition process. Without intending to be bound by theory, it is believed that the use of an ion filter can improve the conformality of the deposition of molybdenum films. In one or more embodiments, the ion filter includes a showerhead. In some embodiments, the showerhead is a dual-channel showerhead, such as the dual-channel showerheads described herein.

[0047]

[0055] In some embodiments, a second molybdenum film is deposited on the plasma-treated first molybdenum film in step 16. In one or more embodiments, the second molybdenum film is formed by the same process as the first molybdenum film in step 12. In some embodiments, the second molybdenum film is formed by exposing the plasma-treated first molybdenum film in step 14 to a molybdenum-containing precursor and an organosilane reducing agent. In some embodiments, the second molybdenum film is formed by exposing the plasma-treated first molybdenum film in step 14 to a plasma formed from a molybdenum-containing precursor and an organosilane reducing agent. The plasma can include any suitable plasma known to those skilled in the art. In some embodiments, the plasma is formed from hydrogen (H), nitrogen (N), or silane (Six 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.

[0048]

[0056] 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 temperatures below 400° C. A molybdenum-containing precursor and a plasma formed from a reducing agent (e.g., hydrogen (H), nitrogen (N), or silane (Si)) are reacted with each other to form a molybdenum-containing precursor. x H y Gas-phase reactions with reactive gases (e.g., a plasma formed from one or more of the molybdenum-containing precursors) can be avoided by implementing a dual-channel showerhead including a first channel and a second channel. Here, a molybdenum-containing precursor is flowed through the first channel and a plasma formed from a reducing agent is flowed through the second channel, or vice versa. In some embodiments, the plasma formed from the molybdenum-containing precursor and the reducing agent is 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. In this case, a first reactive gas (e.g., a molybdenum-containing precursor) and a second reactive gas (e.g., a plasma formed from a reducing agent) are simultaneously supplied to the reaction zone but separated by an inert gas curtain and / or a vacuum curtain.

[0049]

[0057] Figure 2 shows a cross-sectional isometric view of a processing chamber according to one or more embodiments. Figure 3 shows a cross-sectional view of a processing chamber according to one or more embodiments. The processing chambers shown in Figures 2 and 3 are further described below.

[0050]

[0058] 4A-4C illustrate cross-sectional views of a deposition process on a substrate that produces a low electrical resistivity film on a dielectric layer, according to one or more embodiments. Referring first to FIG. 4A, a substrate 402 is shown having a surface, such as top surface 403, and a dielectric layer 404 on top surface 403. Referring to FIG. 4B, in one or more embodiments, a first molybdenum film 406 (e.g., a molybdenum-containing liner 406) is shown directly on dielectric layer 404 on top surface 403 of substrate 402. Referring to FIG. 4C, in one or more embodiments, a molybdenum film 408 is shown on molybdenum-containing liner 406.

[0051]

[0059] 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 phosphate (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, cleaned silicon (Si), boron-doped silicon germanium (SiGeB), cleaned silicon phosphide (SiP), titanium aluminum (TiAl), ruthenium (Ru), tungsten (W), and molybdenum (Mo). Although some examples of materials from which the substrate 402 can be fabricated are provided, any material that can serve as a foundation for passive and active electronic devices (e.g., transistors, memory, capacitors, inductors, resistors, switches, integrated circuits, amplifiers, optoelectronic devices, or any other electronic device) can be utilized.

[0052]

[0060] In some embodiments, the substrate 402 may comprise a dielectric material (e.g., a silicon-containing dielectric material and / or a metal oxide dielectric material). In some embodiments, the substrate 402 may comprise a silicon oxide (SiO x ), silicon suboxide, silicon nitride (SiN x ), silicon nitride (Si3N4), silicon carbide (SiC x ), silicon oxycarbide (SiO x C y ), silicon carbonitride (SiC x N y ), silicon oxynitride (SiO x N y ), tantalum nitride (TaN), hafnium oxide (HfO x ), or combinations thereof.

[0053]

[0061] 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 step 12 of method 10 described above. In one or more embodiments, the first molybdenum film 406 described herein refers to a molybdenum-containing liner 406. In embodiments in which the 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 a plasma. In one or more embodiments, the deposited film may be treated with a plasma. In embodiments in which the molybdenum-containing liner 406 is present, the molybdenum-containing liner 406 is formed by step 12 (e.g., 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 .

[0054]

[0062] The molybdenum-containing liner 406 can have any suitable thickness, hi some embodiments, the molybdenum-containing liner 406 has a thickness of 20 Å or less (including, for example, a thickness ranging from 0.5 Å to 20 Å, 0.5 Å to 15 Å, 0.5 Å to 10 Å, 1 Å to 9 Å, 2 Å to 8 Å, 3 Å to 8 Å, 4 Å to 7 Å, or 5 Å to 6 Å).

[0055]

[0063] In one or more embodiments, the second molybdenum film 408 is deposited directly on the molybdenum-containing liner 406. The second molybdenum film 408 may have any suitable thickness. As described herein, in some embodiments, the first molybdenum film 406 may be referred to as the molybdenum-containing liner 406, and the second molybdenum film 408 may be referred to as the molybdenum film 408. The second molybdenum film 408 may be formed by the same process (e.g., step 12) as the molybdenum-containing liner 406.

[0056]

[0064] In embodiments in which a molybdenum-containing liner 406 is present, a second molybdenum film 408 is formed by step 16 (e.g., by exposing the molybdenum-containing liner 406, which was treated with plasma in step 14, to a molybdenum-containing precursor and an organosilane reducing agent).

[0057]

[0065] In some embodiments, the second molybdenum film 408 is formed by exposing the molybdenum-containing liner 406, which was plasma treated in step 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 may include hydrogen (H), nitrogen (N), 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]

[0066] Advantageously, the molybdenum film 408 on the molybdenum-containing liner 406 has at least a 30% reduction in resistivity compared to a titanium nitride (TiN) film on which the molybdenum film was conformally deposited. In some embodiments, the conformally deposited molybdenum-containing liner 406 and molybdenum film 408 define a film stack having a resistivity of 35 μΩ-cm or less when the conformally deposited molybdenum-containing liner 406 and molybdenum film 408 have a combined thickness of about 100 Å. Advantageously, it has been found that treating the conformally deposited molybdenum-containing liner 406 and / or molybdenum film 408 using methods described herein, including using a plasma such as hydrogen (H) radicals, can more efficiently remove impurities, further increase the film grain size, and reduce resistivity. In some embodiments, the resistivity of the film stack when the conformally deposited molybdenum-containing liner 406 and the molybdenum film 408 have a combined thickness of about 100 Å is in the range of 15 μΩ-cm to 35 μΩ-cm (including in the range of 20 μΩ-cm to 35 μΩ-cm, 25 μΩ-cm to 35 μΩ-cm, 20 μΩ-cm to 25 μΩ-cm, or 30 μΩ-cm to 35 μΩ-cm). In some embodiments, the resistivity of the film stack when the conformally deposited molybdenum-containing liner 406 and the molybdenum film 408 have a combined thickness of about 100 Å is about 31 μΩ-cm.

[0059]

[0067] Another aspect of the present disclosure relates to an electronic device including a molybdenum-containing liner (e.g., a first molybdenum film) conformally deposited on a dielectric surface and a molybdenum film (e.g., a second molybdenum film) formed directly on the molybdenum-containing liner. The method of the present invention can be utilized at any device node, but can be particularly advantageous at device nodes of about 25 nm or less, for example, from about 5 nm to about 25 nm.

[0060]

[0068] A further aspect of the present disclosure relates to a method that is part of a gap-fill process. In some embodiments, a molybdenum-containing liner is deposited on a dielectric surface having one or more high-aspect-ratio gap features, including vertical and / or horizontal gap features, and the molybdenum in the gap features forms a current-carrying horizontal interconnect. Without intending to be bound by theory, the molybdenum-filled gap on the conformally deposited molybdenum-containing liner according to one or more embodiments of the method described herein improves the electrical operation of the integrated circuit by minimizing power loss and overheating within the integrated circuit in which the gap is filled with molybdenum.

[0061]

[0069] 5A-5C, a method of filling a feature formed on a top surface 503 of a substrate 502 is illustrated with respect to feature 500 defining a trench, the trench having a top surface 503, a bottom surface 530, with a gap between the two surfaces defined by opposing sidewalls 520. Substrate 502 can include any of the non-limiting materials for substrate 402 described above with respect to FIGS. 4A-4C. In the embodiment shown in FIGS. 4A-4C, substrate 402 includes a dielectric region.

[0062]

[0070] 5B , a method of filling a feature includes conformally depositing a molybdenum-containing liner 506 directly onto a dielectric region including a top surface 503 within a feature 500 on a surface of a substrate 502, the feature 500 including at least one surface defining a trench, the trench including a top surface 503, a bottom surface 530, and two opposing sidewalls 520 comprising a dielectric. In one or more embodiments, the molybdenum-containing liner 506 is conformally deposited directly onto the dielectric region by step 12.

[0063]

[0071] 5C , the method includes depositing a molybdenum film 508 on the conformally deposited molybdenum-containing liner 506 to fill the feature 500, wherein the molybdenum film 508 is substantially free of seams or voids. In some embodiments, the molybdenum film 508 is deposited directly on the conformally deposited molybdenum-containing liner 506 via step 16 (e.g., by exposing the surface of the molybdenum-containing liner 506 to a molybdenum-containing precursor and an organosilane reducing agent via one or more of atomic layer deposition (ALD), chemical vapor deposition (CVD), or pulsed CVD (pCVD) to fill the feature 500). The atomic layer deposition (ALD) process of one or more embodiments is a thermal process and does not involve the use of a plasma. In one or more embodiments, the deposited film may be treated with a plasma. The surface of the molybdenum-containing liner 506 may be exposed to, for example, one or more ALD cycles. The one or more ALD cycles include 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 a molybdenum film 508 to a desired thickness to fill the feature 500.

[0064]

[0072] In some embodiments, the molybdenum film 508 is formed in step 16 by exposing the molybdenum-containing liner 506, which was plasma treated in step 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 may include hydrogen (H), nitrogen (N), 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.

[0065]

[0073] In one or more specific embodiments, when the molybdenum-containing precursor includes molybdenum hexafluoride (MoF), the plasma does not include hydrogen (H). When the molybdenum-containing precursor includes molybdenum hexafluoride (MoF) and the plasma includes hydrogen (H), the reactants can be used to thermally deposit molybdenum films at temperatures above 400°C, but the reaction generates significant amounts of hydrofluoric acid (HF), which is believed to have adverse effects on the underlying low-k dielectric material.

[0066]

[0074] While the figure shows a substrate 502 with a single feature 500 for illustrative purposes, one skilled in the art will understand that multiple features 500 may be present. The shape of the feature 500 may be any suitable shape, including, but not limited to, a trench and a cylindrical via. The term "feature" as used in this regard refers to an intentional surface irregularity. Suitable examples of features include, but are not limited to, a trench having a top surface, a bottom surface, and two opposing sidewalls comprising a dielectric material; a peak having a top and two sidewalls extending upward from a surface; and a via having sidewalls extending downward from a surface including a bottom. In some embodiments, the bottom of the via includes an open bottom defined or bounded by an underlying material, such as a dielectric material, which may also define two sidewalls; or the underlying material of 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 includes one or more of a trench or a via. In specific embodiments, the 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. The trench 500 has a depth to a bottom 530 and a width between two opposing sidewalls 520. In some embodiments, the depth is in the 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 the 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, the trench 500 has an aspect ratio (depth / width) in the range of 1:1 to 20:1, 5:1 to 20:1, 10:1 to 20:1, or 15:1 to 20:1.

[0067]

[0075] In some embodiments, the molybdenum film 508 is laterally bounded by two opposing sidewalls 520 of the at least one feature 500. As used in this regard, "laterally bounded" means that the deposited material does not extend beyond the intersection between the top surface 503 and the two opposing sidewalls 520. In some embodiments, the molybdenum film 508 extends above the at least one feature 500. In some embodiments, the molybdenum film 508 fills the trench 500. As used in this regard, 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 that fills 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.

[0068]

[0076] Embodiments of the present disclosure advantageously provide a molybdenum film 508 having 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 or substantially free of voids and seams. As used in this regard, "substantially free" means that, at the atomic level, 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 contains voids and / or seams.

[0069]

[0077] The methods described herein can be performed in any suitable process chamber known to those skilled in the art. The methods described herein can be performed, for example, in 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 can include, but is not limited to, the Continuum®, Olympia®, Tesseract™, PRODUCER® system and any associated PRODUCER platform, PRECISION5000® system, Trillium®, and / or Selectra™ etch chambers, all of which are available from Applied Materials, Inc., Santa Clara, California. In some embodiments, the process chamber comprises a Selectra® etch chamber including a plasma generation source and a molybdenum precursor source for flowing a molybdenum-containing precursor. In some embodiments, the entire process chamber, or portions thereof, are coated with nickel to reduce unwanted particle generation.

[0070]

[0078] In one or more embodiments, the 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 at a temperature in the range of about 200° C. to about 550° C., including in the range of about 200° C. to about 300° C. In one or more embodiments, the pedestal in the processing chamber supports a substrate.

[0071]

[0079] In one or more embodiments, the molybdenum-containing precursor is delivered to the process chamber from a first ampoule, and the organosilane reducing agent is delivered to the process chamber from a second ampoule. In some embodiments, the first ampoule and / or the second ampoule are maintained at a temperature ranging from about 30°C to about 150°C, including from 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 ranging from 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.

[0072]

[0080] In some embodiments, a portion of the processing chamber and / or the substrate is coated with molybdenum prior to exposing the molybdenum coated portion to the plasma.

[0073]

[0081] The present disclosure presents methods for use in single-wafer or multi-wafer (also referred to as batch) processing chambers. Figures 2 and 3 show a processing chamber 100 in accordance with one or more embodiments of the present disclosure. Figure 2 shows the processing chamber 100 illustrated as a cross-sectional isometric view. Figure 3 is a cross-sectional view of the processing chamber 100. Accordingly, some embodiments of the present disclosure are directed to a processing chamber 100 incorporating a substrate support 200.

[0074]

[0082] The processing chamber 100 includes a housing 102 with walls 104 and a bottom 106. The housing 102, together with a top plate 300, defines a processing space 109, also referred to as an interior space. In some embodiments, a portion of the processing space 109 or the entire processing space 109 is coated with nickel to reduce the formation of unwanted particles. 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® etch chamber including a plasma generation source (not shown) on the top plate 300 and a molybdenum precursor source for flowing a molybdenum-containing precursor.

[0075]

[0083] The illustrated processing chamber 100 includes multiple processing stations 110. The processing stations 110 are disposed within the interior space 109 of the housing 102 and are positioned in a circle around the axis of rotation 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 surfaces 114 of the gas injectors 112 are substantially coplanar. A processing station 110 is defined as an area in which processing can occur. For example, in some embodiments, a processing station 110 is defined as an area 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 the substrate support surface and forms part of the substrate support 200.

[0076]

[0084] The processing station 110 can be configured to perform any suitable process and provide any suitable process 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 (ALD) apparatus can have a showerhead or vortex-type gas injector. In some embodiments, the processing station 110 includes a dual-channel showerhead as described herein. In some embodiments, a portion of the dual-channel showerhead or the entire dual-channel showerhead is nickel-coated to reduce unwanted particle formation. On the other hand, a processing station 110 configured to operate as a plasma station can have one or more electrodes and / or grounded plate configurations to generate a plasma while allowing plasma gas to flow toward the wafer. The embodiment shown in FIG. 3 has a different type of processing station 110 on the left side of the drawing (processing station 110a) than on the right side of the drawing (processing station 110b). Suitable processing stations 110 include, but are not limited to, thermal processing stations, microwave plasma, three-electrode CCP, inductively coupled plasma, parallel plate CCP, UV exposure, laser processing, pumping chambers, annealing stations, and metrology stations.

[0077]

[0085] In some embodiments, the steps of the methods described herein are each performed in the same processing chamber. In some embodiments, the steps of the methods described herein are each performed in different processing chambers. In some embodiments, the different processing chambers are coupled together as part of a processing system. In some embodiments, the steps of the methods described herein are performed without an intervening vacuum break.

[0078]

[0086] In some embodiments, one or more of the steps of the methods described herein are performed in situ without breaking vacuum, hi some embodiments, one or more of the steps of the methods described herein are performed ex situ.

[0079]

[0087] As used herein, the term "in situ" refers to steps of the methods described herein that are each performed in the same processing chamber or different processing chambers that are linked as part of a processing system such that each of the steps of the methods described herein is performed without an intervening vacuum break.

[0080]

[0088] As used herein, the term "ex situ" refers to steps of the methods described herein that are each performed in the same processing chamber or in different processing chambers, such that one or more of the steps of the methods described herein are performed with an intervening vacuum break.

[0081]

[0089] 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.

[0082]

[0090] In some embodiments, the non-transitory computer-readable medium comprises instructions that, when executed by a controller of a process chamber, cause the process chamber to deposit a molybdenum film having molybdenum-carbon (Mo-C) bonds directly on the 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 treat the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film.

[0083]

[0091] In some embodiments, the non-transitory computer-readable medium, when executed by a controller of a processing chamber, includes instructions that, when executed by a controller of the 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 of 450° C. or less, the first molybdenum film having molybdenum-carbon (Mo—C) bonds, 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; 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.

[0084]

[0092] Throughout this specification, references to "one embodiment," "a particular embodiment," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one or more embodiments," "a particular embodiment," "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.

[0085]

[0093] Although the disclosure herein has been described with reference to particular embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed method and apparatus without departing from the spirit and scope of the disclosure. Therefore, the present disclosure is intended to cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. 1. 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 of 450° C. or less, wherein the molybdenum film has molybdenum-carbon (Mo—C) bonds; treating the molybdenum film with a plasma to remove carbon and form a substantially carbon-free molybdenum film; A deposition method comprising:

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

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

4. The molybdenum-containing precursor is molybdenum pentachloride (MoCl ５ ), molybdenum dioxide dichloride (MoO ２ Cl ２ ), molybdenum oxytetrachloride (MoOCl ４ ), molybdenum hexafluoride (MoF ６ 2. The deposition method of claim 1, wherein the organic compound comprises one or more of molybdenum, bis(tert-butylimido)-bis(dimethylamido)molybdenum, molybdenum hexacarbonyl, bis(tert-butylimido)-bis(dimethylamido)molybdenum, or bis(ethylbenzene)molybdenum.

5. the organosilane reducing agent comprises a compound of general formula (II) or general formula (III), Here, 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. 10. 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. 10. The deposition method of claim 1, wherein the molybdenum film is deposited at a temperature ranging from 250°C to 400°C and a pressure ranging from 1 Torr to 300 Torr.

9. 10. The deposition method of claim 1, wherein 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.

10. The plasma is hydrogen (H ２ ), nitrogen (N ２ ), or silane (Si ｘ H ｙ 10. The deposition method of claim 9, wherein the metal layer is formed from one or more of:

11. The plasma is hydrogen (H ２ 11. The deposition method of claim 10, wherein the plasma is an ex-situ plasma formed from argon, argon, and argon ions.

12. 10. The deposition method of claim 1, wherein the substantially carbon-free molybdenum film contains 1 atomic % or less of carbon (C).

13. 1. A method of filling features formed on a surface of a substrate, the method comprising: conformally depositing a first molybdenum film directly on the feature by exposing the feature to a molybdenum-containing precursor and an organosilane reducing agent at a temperature of 450° C. or less, the first molybdenum film having molybdenum-carbon (Mo—C) bonds, the feature including a surface defining a trench, the trench including a top surface, a bottom surface comprising a metallic 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; depositing a second molybdenum film on the substantially carbon-free first molybdenum film to fill the feature; A method comprising:

14. The molybdenum-containing precursor is molybdenum pentachloride (MoCl ５ ), molybdenum dioxide dichloride (MoO ２ Cl ２ ), molybdenum oxytetrachloride (MoOCl ４ ), molybdenum hexafluoride (MoF ６ ), molybdenum hexacarbonyl, bis(tert-butylimido)-bis(dimethylamido)molybdenum, or bis(ethylbenzene)molybdenum.

15. the organosilane reducing agent comprises a compound of general formula (II) or general formula (III), Here, 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. 16. The method of claim 15, wherein the organosilane reducing agent comprises 1,4-bis(trimethylsilyl)-2-methyl-2,5-cyclohexadiene.

17. 14. The method of claim 13, wherein the first molybdenum film is substantially carbon-free and comprises 1 atomic % or less of carbon (C).

18. The plasma is hydrogen (H ２ ), nitrogen (N ２ ), or silane (Si ｘ H ｙ 14. The method of claim 13, wherein the plasma source comprises 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 plasma source includes an ion filter.

20. 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, wherein the molybdenum-containing precursor is flowed through the first channel and the organosilane reducing agent is flowed through the second channel.

Images