Conformal Molybdenum Deposition

Abstract

Embodiments of the present disclosure provide a conformally deposited molybdenum film with reduced resistivity and a method of forming the same. The method includes converting an amorphous silicon layer to a metal layer by thermally immersing the amorphous silicon layer containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a part of the silicon atoms in the amorphous silicon layer are replaced by metal atoms selected from the group consisting of molybdenum atoms and tungsten atoms. The method includes conformally depositing a molybdenum film on the metal layer.

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure relate to metal film deposition. More specifically, embodiments of the present disclosure are directed to conformal molybdenum deposition.

Background Art

[0002]

[0002] As circuit integration density increases, there is a growing need to improve the uniformity and process control regarding layer thickness. As a result, various techniques have been developed to deposit layers on substrates in a cost-effective manner while maintaining control over layer characteristics. Chemical vapor deposition (CVD) is one of the most common deposition processes used to deposit layers on substrates.

[0003]

[0003] Cyclic deposition or atomic layer deposition (ALD) is a type of CVD that exhibits excellent step coverage. ALD utilizes chemisorption techniques to supply precursor molecules to the substrate surface in cyclic cycles. By means of the cycles, the upper surface of the substrate is exposed to a first precursor, a purge gas, a second precursor, and a purge gas. The first precursor and the second precursor react to form a product compound as a film on the substrate surface. This cycle is repeated to form a layer of a desired thickness. As advanced microelectronic devices become increasingly complex, stringent requirements are imposed on currently used deposition techniques. Molybdenum and molybdenum-based films include attractive materials and conductive properties. These films have been proposed and tested for component applications from the front end to the back end of semiconductor and microelectronic devices. For example, in both blanket film and gap fill applications, a liner film (e.g., a TiN liner film) is deposited to achieve low resistivity molybdenum deposition. In gap fill applications, TiN is deposited in the gaps to achieve both low resistivity and conformal deposition. Conformal deposition is often required to uniformly deposit a metal film on a three-dimensional structure including high aspect ratio features.

[0004]

[0004] To achieve a low resistivity of the molybdenum film, an improved metal liner or metal layer continues to be needed. Accordingly, to achieve conformal molybdenum deposition with improved film characteristics, an improved material and method for depositing a liner film are needed.

Summary of the Invention

[0005]

[0005] One or more embodiments of the present disclosure include forming an amorphous silicon layer directly on a dielectric layer on a surface of a substrate, and subjecting the amorphous silicon layer containing silicon atoms to thermal immersion in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a part of the silicon atoms in the amorphous silicon layer are replaced by metal atoms selected from the group consisting of molybdenum atoms and tungsten atoms, thereby converting the amorphous silicon layer into a metal layer and forming a metal layer having a thickness in the range of 10 angstroms to 50 angstroms, and conformally depositing a molybdenum film on the metal layer.

[0006]

[0006] Further embodiments of the present disclosure are directed to a method of filling features formed on a surface of a substrate. The method of filling features formed on a surface of a substrate includes forming an amorphous silicon layer directly in a dielectric region within a feature on an upper surface of the substrate. The feature includes at least one surface defining a via, and the via includes a bottom surface containing a dielectric and two sidewalls. The method further includes converting the amorphous silicon layer to a metal layer by thermally immersing the amorphous silicon layer containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a portion of the silicon atoms in the amorphous silicon layer are replaced by metal atoms selected from the group consisting of molybdenum atoms and tungsten atoms, to form a metal layer having a thickness within the range of 10 angstroms to 50 angstroms. The method includes conformally depositing a molybdenum film on the metal layer to fill the feature. The conformally deposited molybdenum film is substantially free of seams and voids.

[0007]

[0007] To enable a more detailed understanding of the features of the present disclosure described above, a more specific description of the present disclosure, briefly summarized above, is obtained by referring to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the accompanying drawings show only typical embodiments of the present disclosure and, therefore, the present disclosure should not be considered to be limited in scope since it can recognize other equally effective embodiments. The embodiments described herein are shown by way of example and not limitation in the figures of the accompanying drawings, and like reference numerals indicate like elements.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 2D

Figure 3A

Figure 3B

Figure 3C

Figure 3D

Figure 3E

[0009]

[0018] Before describing some exemplary embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of the configurations or process steps described in the following description. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways.

[0010]

[0019] As used herein, the term "about" means approximately or nearly and means a variation of up to ±15% of the numerical value, in light of the numerical value or range specified. For example, values that differ by ±14%, ±10%, ±5%, ±2%, or ±1% satisfy the definition of about.

[0011]

[0020] As used in this specification and the appended claims, the terms "substrate" or "wafer" refer to the surface or a portion of the surface on which a process acts. Also, when reference is made to a substrate, it will be understood by those skilled in the art that it may refer only to a portion of the substrate, unless otherwise explicitly stated in the context. In addition, when reference is made to deposition on a substrate, it can mean both a bare substrate and a substrate on which one or more films or features have been deposited or formed.

[0012]

[0021] As used herein, "substrate" refers to any substrate or the surface of a material formed on a substrate on which film processing is performed during a manufacturing process. For example, the substrate surface on which processing can be performed can include any other material such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, as well as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. The substrate can be exposed to a pretreatment process to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to directly performing film processing on the surface of the substrate itself, in the present disclosure, as will be disclosed in more detail below, any of the disclosed film processing steps can be performed in an underlying layer formed on the substrate. The term "substrate surface" is intended to include an underlying layer as indicated by the context. Thus, for example, when a film / layer or a partial film / layer is deposited on the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0013]

[0022] As used herein, the term "substrate surface" refers to any substrate surface on which a layer can be formed. The substrate surface can have one or more features formed therein, one or more layers formed thereon, and combinations thereof. The shape of the feature can be any suitable shape including, but not limited to, peaks, trenches, and cylindrical vias. The term "feature" as used in this way refers to any intentional irregularity of a surface. Suitable examples of features include trenches having an upper portion, two sidewalls, and a bottom portion, peaks having an upper portion and two sidewalls extending upwardly from the surface, and vias having an open bottom and a sidewall extending downwardly from the surface, but are not limited thereto.

[0014]

[0023] The term "selectively" as used in this specification and the appended claims refers to a process that acts on a first surface and has a greater effect than another second surface. Such a process would be expressed as acting "selectively" on the first surface rather than the second surface. The expression "over" as used in this context does not mean the physical orientation of one surface over another surface, but rather the relationship of the thermodynamic or mechanical properties of the chemical reaction of one surface to another surface.

[0015]

[0024] The term "on" indicates that there is direct contact between elements. The term "directly on" indicates that there is direct contact between elements without intervening elements.

[0016]

[0025] The terms "precursor", "reactant", "reactive gas", etc. as used in this specification and the appended claims are used interchangeably to refer to any gaseous species capable of reacting with the substrate surface.

[0017]

[0026] As used herein, "atomic layer deposition" or "cyclic deposition" refers to depositing a material layer on a substrate surface by sequential exposure to two or more reactive compounds. The substrate or a portion of the substrate is separately exposed to two or more reactive compounds introduced into the reaction zone of the processing chamber. In a time-domain ALD process, the exposure to each reactive compound is separated by a time delay, whereby each compound can adhere to and / or react on 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 the material on the substrate surface, are simultaneously exposed to two or more reactive compounds such that any given point on the substrate is not substantially simultaneously exposed to a plurality of reactive compounds. As used herein and in the appended claims, the term "substantially" when used in this context means that, as understood by one of ordinary skill in the art, a small portion of the substrate may be exposed by diffusion to a plurality of reactive gases simultaneously, and the simultaneous exposure is not intended.

[0018]

[0027] In one aspect of a time-domain ALD process, after a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, a first time delay ensues. Next, after a second precursor or compound B is pulsed into the reaction zone, a second delay occurs. During each time delay, a purge gas (e.g., argon) is introduced into the processing chamber to purge the reaction zone or otherwise remove any remaining reactive compounds or reaction by-products from the reaction zone. Alternatively, the purge gas may flow continuously throughout the deposition process such that only the purge gas flows during the time delay between pulses of the reactive compounds. The reactive compounds are pulsed alternately until a desired film or film thickness is formed on the substrate surface. In either case, an ALD process that pulses compound A, the purge gas, compound B, and the purge gas constitutes one cycle. The cycle can be initiated with either compound A or compound B, and each stage of the cycle can be continued until a film of a predetermined thickness is achieved.

[0019]

[0028] In one embodiment of the spatial ALD process, a first reactive gas and a second reactive gas (e.g., hydrogen gas) are simultaneously supplied to the reaction zone, but are separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas supply device such that any given point on the substrate is exposed to the first reactive gas and the second reactive gas.

[0020]

[0029] Embodiments of the present disclosure advantageously provide a method for significantly improving the resistivity of a blanket molybdenum film deposited on an underlying tungsten or molybdenum layer formed by the method described in the present disclosure. One or more embodiments provide a method of forming a metal layer containing metal or tungsten by replacing silicon from an amorphous silicon layer on a dielectric using a continuous thermal process. In one or more embodiments, a continuous process is run for a period of time to form a metal layer having a predetermined process without repeating the dip coating process used to form the metal layer. In one or more embodiments, the metal layer formed on the dielectric by replacement of amorphous silicon has a thickness in the range of 10 angstroms to 50 angstroms, 15 angstroms to 50 angstroms, 20 angstroms to 50 angstroms, 25 angstroms to 50 angstroms, 30 angstroms to 50 angstroms, 35 angstroms to 50 angstroms, or 40 angstroms to 50 angstroms. Without wishing to be bound by any particular theory or principle, it is believed that not repeating the continuous process leads to an improvement in reducing the sheet resistivity of the molybdenum film formed on the metal layer. In a further embodiment, advantageously, a method is provided for reducing the sheet resistivity of bottom-up gap filling for vias with improved characteristics of the molybdenum film.

[0021]

[0030] Embodiments of the present disclosure are illustrated by diagrams showing devices (e.g., transistors) according to one or more embodiments of the present disclosure and processes for forming the devices. The processes illustrated are merely examples of possible uses of the disclosed processes, and those skilled in the art will recognize that the disclosed processes are not limited to the uses shown.

[0022]

[0031] FIG. 1 shows a process flow diagram of a deposition method 100 according to one or more embodiments of the present disclosure. The deposition method 100 includes, in operation 110, forming a direct amorphous silicon layer on a dielectric surface, such as a dielectric layer on a substrate or a dielectric region of a substrate. The deposition method 100 includes, in operation 120, converting the amorphous silicon layer into a metal layer by thermally immersing the amorphous silicon layer containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a portion of the silicon atoms in the amorphous silicon layer are replaced by metal atoms present during the process of thermally immersing the amorphous silicon layer. In operation 130, the deposition method 100 includes conformally depositing a molybdenum film on the metal layer.

[0023]

[0032] The substrate 202 can be any suitable substrate material. In one or more embodiments, the substrate 202 includes a semiconductor material (e.g., 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 400 includes one or more of silicon (Si), germanium (Ge), gallium (Ga), arsenic (As), indium (In), phosphorus (P), or selenium (Se). Although some examples of materials that can constitute the substrate 202 are provided, any material that can function as a basis for constructing 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.

[0024]

[0033] In some embodiments, the substrate may include a dielectric material (e.g., silicon-containing dielectric materials and metal oxide dielectric materials). In some embodiments, the substrate may include one or more dielectric surfaces including, but not limited to, silicon-containing dielectric materials such as silicon dioxide (SiO2), silicon suboxide, silicon nitride (Si3N4), silicon oxynitride (SiON), silicon oxycarbide (SiOC), silicon oxycarbide nitride (SiOCN), silicon carbonitride (SiCN). In some embodiments, the substrate may include one or more dielectric surfaces including, but not limited to, metal oxides such as aluminum oxide (Al2O3), hafnium oxide (HfO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), titanium oxide (TiO2), hafnium silicate (HfSiO x ), and lanthanum oxide (La2O3).

[0025]

[0034] The deposition process of the molybdenum film is a process capable of forming a thin film that is continuous over a large substrate area. One or more embodiments provide a process optimized such that the deposition process produces a molybdenum film with a low electrical resistivity.

[0026]

[0035] Figures 2A - D show cross - sectional views of a deposition process on a substrate according to one or more embodiments for generating a low electrical resistivity film on a dielectric layer. First, referring to Figure 2A, a substrate 2A is shown having a surface such as upper surface 203 and a dielectric layer 204 on upper surface 203. Referring to Figure 2B, in one or more embodiments, the deposition method includes forming an amorphous silicon layer 206 directly on dielectric layer 204 on upper surface 203 of substrate 202.

[0027]

[0036] Referring to Figure 2C, the method according to one or more embodiments further includes converting amorphous silicon layer 206 into metal layer 208 by thermally immersing amorphous silicon layer 206 containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a portion of the silicon atoms in the amorphous silicon layer are replaced by metal atoms selected from the group consisting of molybdenum atoms and tungsten atoms, to form a metal layer 208 having a thickness within the range of 10 angstroms to 50 angstroms or any thickness described herein.

[0028]

[0037] The method further includes conformally depositing a molybdenum film 210 on metal layer 208 to obtain the device shown in Figure 2D.

[0029]

[0038] In one or more embodiments, metal layer 208 is formed by thermally immersing amorphous silicon in a single non - repeating step. In other words, the thermal immersion process is a continuous process that is carried out over a certain period of time to achieve a predetermined thickness.

[0030]

[0039] In some embodiments, the dielectric layer 204 comprises silicon oxide (SiO x ), silicon nitride (SiN x ), silicon carbide (SiCx), silicon carbonitride (SiCxNy), silicon oxynitride (SiOxNy), a low-k material, or a combination thereof. In some embodiments, forming the amorphous silicon layer 206 includes exposing the surface of the substrate having the dielectric layer 204 to silane (SiH4), disilane (Si2H6), or trisilane (Si3H8).

[0031]

[0040] In embodiments where the metal layer 208 comprises tungsten, consists essentially of tungsten, or consists of tungsten, the tungsten compound is selected from the group consisting of tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten(VI) oxytetrachloride (WOCl4), and tungsten pentachloride (WCl5). In embodiments where the metal layer 208 comprises tungsten metal, consists essentially of tungsten metal, or consists of tungsten metal, the molybdenum compound is selected from the group consisting of molybdenum pentachloride (MoCl5), molybdenum oxychloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6).

[0032]

[0041] In one or more embodiments, hot-dipping the amorphous silicon layer is performed at a temperature in the range of 300 °C to 600 °C (e.g., a temperature in the range of 300 °C to 550 °C or 300 °C to 500 °C), a pressure in the range of 10 Torr to 300 Torr (e.g., a pressure in the range of 10 Torr to 250 Torr or 10 Torr to 200 Torr), and the time is in the range of 30 seconds to 600 seconds (e.g., in the range of 300 seconds to 500 seconds or 300 seconds to 400 seconds). The time is selected to obtain a predetermined or desired thickness of the metal layer 208. In some embodiments, the metal compound during hot-dipping is contained in an ampoule or container maintained at a temperature in the range of 30 °C to 150 °C.

[0033]

[0042] In one or more embodiments, conformally depositing the molybdenum film 210 includes one or more of atomic layer deposition (ALD), co-flow of a molybdenum precursor and hydrogen (H2), or chemical vapor deposition (CVD).

[0034]

[0043] According to some embodiments, conformally depositing the molybdenum film includes utilizing one or more of atomic layer deposition (ALD), co-flow of a molybdenum precursor and hydrogen (H2), or chemical vapor deposition (CVD). In some embodiments, the molybdenum precursor utilized during deposition of the molybdenum film includes one or more of molybdenum pentachloride (MoCl5), molybdenum oxychloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6). In some embodiments, conformally depositing the molybdenum film is performed at a temperature in the range of 300°C to 600°C and a pressure in the range of 10 Torr to 300 Torr. The molybdenum precursor can be contained in an ampoule or container maintained at a temperature in the range of 30°C to 150°C.

[0035]

[0044] Advantageously, the molybdenum film conformally deposited on the metal layer has a resistivity reduced by at least 30% compared to a titanium nitride (TiN) film on which the molybdenum film was conformally deposited. Experimentally, such an improvement was observed in films having a thickness in the range of 100 microns to 120 microns.

[0036]

[0045] Another aspect of the present disclosure relates to a method that is part of a gap filling process. Thus, the molybdenum metal film is deposited on a dielectric surface having one or more high aspect ratio gap features including vertical gap features and / or horizontal gap features. For example, referring to FIG. 3A, the substrate is included.

[0037]

[0046] Referring to FIGS. 3A - 3E, a method of filling a feature 300 formed on the upper surface 303 of a substrate 302 is shown for a feature 300 that is a gap including opposing sidewalls 320 and a bottom surface 330. The substrate 302 can include any of the non - limiting materials described above with respect to FIGS. 2A - D. In the illustrated embodiment, the substrate 302 is a dielectric region.

[0038]

[0047] In one or more embodiments, referring to FIG. 3B, the method of filling the feature 300 includes directly forming an amorphous silicon layer 304 on a dielectric region including the upper surface 303 within the feature 300 on the surface of the substrate 302, where the feature 300 includes at least one surface defining a via, and the via includes a bottom surface 330 including a dielectric and two opposing sidewalls 320.

[0039]

[0048] Referring to FIG. 3C, the method shows converting the amorphous silicon layer into a metal layer 306 by thermally dipping the amorphous silicon layer containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a portion of the silicon atoms in the amorphous silicon layer 304 shown in FIG. 3B are replaced by metal atoms selected from the group consisting of molybdenum atoms and tungsten atoms. FIG. 3D shows the metal layer 308 after complete conversion.

[0040]

[0049] In one or more embodiments, thermally dipping the amorphous silicon layer is performed at a temperature in the range of 300°C to 600°C (e.g., a temperature in the range of 300°C to 550°C or 300°C to 500°C), and a pressure in the range of 10 Torr to 300 Torr (e.g., a pressure in the range of 10 Torr to 250 Torr or 10 Torr to 200 Torr). The time of thermal dipping is selected to fill the feature 300. In some embodiments, the metal compound during thermal dipping is contained in an ampoule or container maintained at a temperature in the range of 30°C to 150°C.

[0041]

[0050] Referring to FIG. 3E, the method includes conformally depositing a molybdenum film 310 on the metal layer 308 to fill the feature 300, and the conformally deposited molybdenum film 310 is substantially free of seams and voids.

[0042]

[0051] According to an embodiment, the thermal soak includes exposing the amorphous silicon layer to one or more of tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten(VI) oxytetrachloride (also referred to as tungsten(VI) oxytetrachloride) (WOCl4), and tungsten pentachloride (WCl5) when the molybdenum film 310 contains tungsten, consists of tungsten, or consists essentially of tungsten. In embodiments where the molybdenum film 310 consists of molybdenum, consists of molybdenum, or consists essentially of molybdenum, the precursor is selected from molybdenum pentachloride (MoCl5), molybdenum(IV) oxytetrachloride (also referred to as molybdenum(IV) oxytetrachloride) (MoOCl4), molybdenum(IV) dioxydichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6).

[0043]

[0052] Conformally depositing the molybdenum film includes one or more of atomic layer deposition (ALD), co-flow of a molybdenum precursor and hydrogen (H2), or chemical vapor deposition (CVD). Molybdenum precursors in the conformally deposited film of one or more embodiments include molybdenum pentachloride (MoCl5), molybdenum(IV) oxytetrachloride (MoOCl4), molybdenum(IV) dioxydichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6).

[0044]

[0053] Advantageously, the molybdenum film 310 conformally deposited on the metal layer 308 has a resistivity that is at least 30% reduced compared to a titanium nitride (TiN) film on which the molybdenum film is conformally deposited. In an embodiment, the molybdenum film is conformally deposited throughout the via.

[0045]

[0054] In some embodiments, conformally depositing the molybdenum film is performed at a temperature in the range of 300 °C to 600 °C and a pressure in the range of 10 Torr to 300 Torr. The molybdenum precursor can be housed in an ampoule or container maintained at a temperature in the range of 30 °C to 150 °C.

[0046]

[0055] These drawings show a substrate 302 having a single feature 300 for illustrative purposes, and those skilled in the art will understand that there may be one or more features 300. The shape of feature 300 can be any suitable shape including, but not limited to, trenches and cylindrical vias. In this regard, the term "feature" means any intentional surface irregularity. Suitable examples of features include, but are not limited to, trenches and vias having a top, two sidewalls, and a bottom, and peaks having a top and two sidewalls. In one or more embodiments, at least one feature 300 includes one or more of a trench or a via. In a particular embodiment, at least one feature 300 includes a via. In a further embodiment, the terms "at least one feature 300" and "via 300" may be used interchangeably. Via 300 has a depth to a bottom surface 330 and a width between two opposing sidewalls 320, 320. 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, via 300 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.

[0047]

[0056] In some embodiments, the processes of deposition method 100 are each performed within the same processing chamber. In some embodiments, the processes of deposition method 100 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 processes of deposition method 100 are performed without the intervention of a vacuum break.

[0048]

[0057] In some embodiments, one or more of the plurality of chemical exposures are performed in situ (in place) without breaking the vacuum. In some embodiments, one or more of the plurality of chemical exposures are performed ex situ (out of place). As used herein, the term "in situ (in place)" refers to the processes of deposition method 100 that are each performed within the same processing chamber or within different processing chambers connected as part of a processing system such that the processes of deposition method 100 are each performed without the intervention of a vacuum break. As used herein, the term "ex situ (out of place)" refers to the processes of deposition method 100 that are each performed within the same processing chamber or different processing chambers such that one or more of the processes of deposition method 100 are performed with the intervention of a vacuum break.

[0049]

[0058] In some embodiments, the molybdenum film 310 is laterally bounded by two opposing sidewalls 320 of at least one feature 300. "Laterally bounded" in this context means that the deposited material does not extend beyond the intersection between the top surface and the two opposing sidewalls 320. In some embodiments, the molybdenum film 310 extends above at least one feature 300. In some embodiments, the molybdenum film 310 fills the via 300. A film that "fills the via" in this context has a volume that occupies at least 95%, at least 98%, or at least 99% of the volume of the via 300. In some embodiments, the film that fills the via has a fill height in the range of 30 nm to 75 nm (including the range of 40 nm to 60 nm).

[0050]

[0059] Embodiments of the present disclosure advantageously provide a molybdenum film 310 having a reduced resistivity as compared to molybdenum films deposited by processes other than the processes described herein (e.g., deposition method 100). Embodiments of the present disclosure advantageously provide a molybdenum film 310 that is void and seam free or substantially void and seam free. As used herein, "substantially void and seam free" means that less than about 5%, 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 430 selectively deposited in situ on an atomic basis contains voids and / or seams.

[0051]

[0060] Without intending to be bound by theory, it is believed that the quality of the deposited molybdenum film 310 is improved by performing the thermal immersion process continuously without repeating the process. In some embodiments, the molybdenum film 310 deposited by the methods described herein exhibits a decrease in resistivity as compared to molybdenum films made by other processes.

[0052]

[0061] Throughout this specification, references to "one embodiment," "certain embodiments," "one or more embodiments," or "an embodiment" mean that the particular feature, structure, material, or characteristic described in connection with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one or more embodiments," "in certain embodiments," "in one embodiment," or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the present disclosure. In one or more embodiments, the particular features, structures, materials, or characteristics are combined in any suitable manner.

[0053]

[0062] The disclosure of this specification has been described with reference to specific embodiments, but it should 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 apparatuses of the present disclosure without departing from the essence and scope of the present disclosure. Accordingly, the present disclosure is intended to cover modifications and variations that are within the scope of the appended claims and their equivalents.

Claims

1. forming an amorphous silicon layer directly on a dielectric layer on a surface of a substrate; thermally immersing the amorphous silicon layer containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a part of the silicon atoms in the amorphous silicon layer is replaced by a metal atom selected from the group consisting of molybdenum atoms and tungsten atoms, thereby converting the amorphous silicon layer into a metal layer; conformally depositing a molybdenum film on the metal layer; A deposition method comprising the steps of:

2. The dielectric is silicon oxide (SiO ｘ ), silicon nitride (SiN ｘ ), silicon carbide (SiC ｘ ), silicon carbonitride (SiCxNy), silicon oxynitride (SiOxNy), a low dielectric constant (low-κ) material, or a combination thereof, the deposition method according to claim 1.

3. Forming the amorphous silicon layer includes exposing the surface of the substrate to silane (SiH ４ ), disilane (Si ２ H ６ ), or trisilane (Si ３ H ８ ). The deposition method according to claim 1.

4. The deposition method according to claim 3, wherein forming the amorphous silicon layer is performed at a temperature in the range of 300 ° C to 600 ° C and a pressure in the range of 10 Torr to 300 Torr.

5. The tungsten compound is selected from the group consisting of tungsten hexafluoride (WF ６ ), tungsten hexachloride (WCl ６ ), tungsten(VI) oxytetrachloride (WOCl ４ ), and tungsten pentachloride (WCl ５ ), and the molybdenum compound is selected from the group consisting of molybdenum pentachloride (MoCl ５ ), molybdenum oxytetrachloride (MoOCl ４ ), molybdenum(IV) dioxydichloride (MoO ２ Cl ２ ), and molybdenum hexafluoride (MoF ６ ). The deposition method according to claim 1

6. The deposition method according to claim 5, wherein thermally immersing the amorphous silicon layer is performed at a temperature in the range of 300 ° C to 600 ° C and a pressure in the range of 10 Torr to 300 Torr.

7. Conformally depositing the molybdenum film includes one or more of atomic layer deposition (ALD), co-flow of a molybdenum precursor and hydrogen (H ２ ), or chemical vapor deposition (CVD), according to the deposition method of claim 1.

8. The molybdenum precursor includes one or more of molybdenum pentachloride (MoCl ５ ), molybdenum oxychloride tetrachloride (MoOCl ４ ), molybdenum dioxide dichloride (MoO ２ Cl ２ ), and molybdenum hexafluoride (MoF ６ ). The deposition method according to claim 7.

9. The deposition method according to claim 7, wherein conformally depositing the molybdenum film is performed at a temperature in the range of 300 ° C to 600 ° C and a pressure in the range of 10 Torr to 300 Torr.

10. The deposition method according to claim 1, wherein the molybdenum film conformally deposited on the metal layer has a resistivity reduced by at least 30% compared to a titanium nitride (TiN) film on which the molybdenum film is conformally deposited.

11. The deposition method according to claim 1, wherein converting the amorphous silicon layer into the metal layer includes thermally immersing the amorphous silicon layer containing silicon atoms in the presence of the molybdenum compound.

12. The deposition method according to claim 1, wherein converting the amorphous silicon layer into the metal layer includes thermally immersing the amorphous silicon layer containing silicon atoms in the presence of the tungsten compound.

13. A method of filling a feature formed on a surface of a substrate, comprising: Forming an amorphous silicon layer directly on a dielectric region within the feature on the surface of the substrate, wherein the feature includes at least one surface defining a via, and the via includes a bottom surface and two sidewalls including the dielectric, and forming the amorphous silicon layer. Thermally immersing the amorphous silicon layer containing silicon atoms in the presence of a metal compound selected from the group consisting of molybdenum compounds and tungsten compounds until at least a part of the silicon atoms in the amorphous silicon layer are substituted by metal atoms selected from the group consisting of molybdenum atoms and tungsten atoms, thereby converting the amorphous silicon layer into a metal layer. Conformally depositing a molybdenum film on the metal layer to fill the feature, wherein the conformally deposited molybdenum film substantially does not contain seams or voids, and filling the feature. A method comprising the above.

14. The hot-dipping includes exposing the amorphous silicon layer to one or more of tungsten hexafluoride (WF ６ ), tungsten hexachloride (WCl ６ ), tungsten(VI) oxychloride (WOCl ４ ), tungsten pentachloride (WCl ５ ), molybdenum pentachloride (MoCl ５ ), molybdenum oxychloride (MoOCl ４ ), molybdenum dioxide dichloride (MoO ２ Cl ２ ), and molybdenum hexafluoride (MoF ６ ), according to the method of claim 13.

15. Conformally depositing the molybdenum film includes one or more of atomic layer deposition (ALD), co-flow of a molybdenum precursor and hydrogen (H ２ ), or chemical vapor deposition (CVD), according to the method of claim 13.

16. The molybdenum precursor contains one or more of molybdenum pentachloride (MoCl ５ ), molybdenum oxychloride (MoOCl ４ ), molybdenum dioxide dichloride (MoO ２ Cl ２ ), and molybdenum hexafluoride (MoF ６ ), and the method according to claim 15.

17. The method according to claim 13, wherein the molybdenum film conformally deposited on the metal layer has a resistivity reduced by at least 30% compared to a titanium nitride (TiN) film on which the molybdenum film is deposited.

18. The method according to claim 13, wherein the molybdenum film is conformally deposited throughout the via.

19. The method according to claim 13, wherein converting the amorphous silicon layer into a metal layer includes thermally immersing the amorphous silicon layer containing silicon atoms in the presence of the tungsten compound.

20. The method according to claim 13, wherein converting the amorphous silicon layer into a metal layer includes thermally immersing the amorphous silicon layer containing silicon atoms in the presence of the molybdenum compound.

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