Conformal molybdenum deposition

Abstract

Embodiments of the present disclosure provide conformally deposited molybdenum films with reduced resistivity and methods of forming the same. The method includes soaking an amorphous silicon layer containing silicon atoms by heat in the presence of a metal compound selected from a group consisting of a molybdenum compound and a tungsten compound until at least a portion of the silicon atoms in the amorphous silicon layer are replaced by metal atoms selected from a group consisting of molybdenum atoms and tungsten atoms, and converting the amorphous silicon layer into a metal layer. A method includes conformally depositing a molybdenum film on a metal layer.

Description

Technical Field

[0001] Embodiments of the present disclosure relate to metal film deposition. More particularly, embodiments of the present disclosure relate to conformal molybdenum deposition. Background Art

[0002] As circuit integration increases, there is an increased demand for greater uniformity and process control with respect to layer thickness. Therefore, various techniques have been developed to deposit layers on substrates in a cost-effective manner while maintaining control over the layer properties. Chemical vapor deposition (CVD) is one of the most common deposition processes used to deposit layers on substrates.

[0003] A variant of CVD that exhibits excellent step coverage is cyclic deposition or atomic layer deposition (ALD). ALD uses chemical adsorption technology to deliver precursor molecules on the substrate surface in a sequential cyclic manner. The cycle exposes the top of 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 the product compound as a film on the substrate surface. Repeat the cycle to form the layer to the desired thickness. The increasing complexity of advanced microelectronic devices places stringent requirements on the deposition techniques currently used. Molybdenum and molybdenum-based films have attractive material and conductor properties. These films have been proposed and tested for applications from the front end to the back end of semiconductors and microelectronic devices. For example, in blanket films and gap filling applications, liner films (e.g., TiN liner films) are deposited to achieve low resistivity molybdenum deposition. In gap filling applications, TiN is deposited in the gap to achieve both low resistivity and conformal deposition. Conformal deposition is often required to uniformly deposit metal films over three-dimensional structures including high aspect ratio features.

[0004] There is a growing need for improved metal liners or metal layers to provide lower resistivity molybdenum films. Thus, there is a need for improved materials and methods for depositing liner films to provide conformal molybdenum deposition with improved film properties. Summary of the invention

[0005] One or more embodiments of the present disclosure relate to a deposition method, comprising forming an amorphous silicon layer directly on a dielectric layer on a surface of a substrate; converting the amorphous silicon layer into a metal layer by heat-immersing the amorphous silicon layer comprising silicon atoms in the presence of a metal compound selected from a 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 a group consisting of molybdenum atoms and tungsten atoms to form a metal layer having a thickness in a range from 10 angstroms to 50 angstroms; and conformally depositing a molybdenum film on the metal layer.

[0006] Additional embodiments of the present disclosure relate to a method for filling a feature formed on a surface of a substrate. The method for filling a feature formed on a surface of a substrate includes: forming an amorphous silicon layer directly on a dielectric region within a feature on a top surface of the substrate. The feature includes at least one surface defining a through hole, the through hole including a bottom surface and two sidewalls containing a dielectric. The method further includes converting the amorphous silicon layer into a metal layer by heat soaking an amorphous silicon layer including silicon atoms in the presence of a metal compound selected from a 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 a group consisting of molybdenum atoms and tungsten atoms to form a metal layer having a thickness in a range from 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 has substantially no gaps or voids. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to be able to understand in detail the manner in which the above-mentioned features of the present disclosure are used, reference may be made to the embodiments for a more specific description of the present disclosure briefly summarized above, some of which are shown in the accompanying drawings. However, it will be noted that the accompanying drawings only illustrate common embodiments of the present disclosure and are not to be considered limiting of its scope, as the present disclosure may admit of other equally effective embodiments. The embodiments as described herein are shown by way of example and are not limited to the figures of the accompanying drawings, in which the same reference numerals indicate similar elements.

[0008] Figure 1 A process flow diagram illustrating a deposition method according to one or more embodiments is shown;

[0009] Figure 2A shows a schematic cross-sectional view of a dielectric layer on a substrate according to one or more embodiments;

[0010] Figure 2B According to one or more embodiments, Figure 2A A schematic cross-sectional view of an amorphous silicon layer on a dielectric layer on a substrate is shown;

[0011] Figure 2C The conversion to a metal layer according to one or more embodiments is shown. Figure 2B A schematic cross-sectional view of an amorphous silicon layer on a substrate in FIG. 1 ; and

[0012] Figure 2D According to one or more embodiments, Figure 2C A schematic cross-sectional view of a metal film on a metal layer in FIG.

[0013] Figure 3A shows a schematic cross-sectional view of a feature on a substrate according to one or more embodiments;

[0014] Figure 3B illustrates a schematic cross-sectional view of an amorphous silicon layer on a feature on a substrate according to one or more embodiments;

[0015] Figure 3C The diagram shows a method of Figure 3B A schematic cross-sectional view of the conversion of an amorphous silicon layer into a metal layer is shown;

[0016] Figure 3D A schematic cross-sectional view showing a metal layer on a feature on a substrate after amorphous silicon has been converted to metal according to one or more embodiments; and

[0017] Figure 3E A substrate including Figure 3D Schematic cross-sectional views of features of metal layers and metal films on metals are shown. DETAILED DESCRIPTION

[0018] Before describing several exemplary embodiments of the present disclosure, it will be understood that the present disclosure is not limited to the details of construction or processing 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.

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

[0020] As used in this specification and the appended claims, the term "substrate" or "wafer" refers to a surface, or portion of a surface, on which a process is performed. As will also be understood by those skilled in the art, unless the context clearly indicates otherwise, references to a substrate may refer to only a portion of a substrate. In addition, references to depositing on a substrate may mean both a bare substrate and a substrate having one or more films or features deposited or formed thereon.

[0021] As used herein, "substrate" refers to any substrate or material surface formed on a substrate on which film processing is performed during the manufacturing process. For example, depending on the application, the substrate surface on which processing can be performed includes materials such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, and any other material such as metal, metal nitride, metal alloy, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. The substrate may be exposed to pre-processing treatments to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake the substrate surface. In addition to processing the film directly on the surface of the substrate itself, in the present disclosure, as disclosed in more detail below, any disclosed film processing step may also be performed on a lower layer formed on the substrate, and the term "substrate surface" is intended to include such lower layers as indicated in the context. Thus, for example, in the case where a film / layer or a portion of a film / layer has been deposited onto the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0022] As used herein, the term "substrate surface" refers to any substrate surface on which a layer may be formed. The substrate surface may have one or more features formed therein, one or more layers formed thereon, and combinations thereof. The shape of the feature may be any suitable shape, including but not limited to peaks, grooves, and cylindrical through holes. As used in this regard, the term "feature" refers to any intentional surface irregularity. Suitable examples of features include but are not limited to a groove having a top, two sidewalls, and a bottom, a peak having a top and two sidewalls extending upward from the surface, and a through hole having sidewalls extending downward from a surface having an open bottom.

[0023] As used in this specification and the appended claims, the term "selective" refers to a treatment that has a greater effect on a first surface than on another, second surface. Such a treatment will be described as acting "selectively" more on the first surface than on the second surface. The term "over" as used in this regard does not imply a physical orientation of one surface on top of another, but rather refers to the relationship of the thermodynamic or kinetic properties of a chemical reaction of one surface relative to another.

[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.

[0025] As used in this specification and the appended claims, the terms "precursor," "reactant," "reactive gas," and the like are used interchangeably to refer to any gaseous species that can react with a substrate surface.

[0026] As used herein, "atomic layer deposition" or "cyclic deposition" refers to the sequential exposure of two or more reactive compounds to deposit a layer of material on a substrate surface. The substrate, or a portion of the substrate, is individually 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 on the substrate surface and subsequently purged from the processing chamber. These reactive compounds are considered to be exposed to the substrate sequentially. In a spatial ALD process, different portions of the substrate surface, or materials on the substrate surface, are simultaneously exposed to two or more reactive compounds, so that any given point on the substrate is not substantially exposed to more than one reactive compound at the same time. As used in this specification and the appended claims, as will be understood by those skilled in the art, the term "substantially" used in this regard means that there is a possibility that a small portion of the substrate may be exposed to multiple reactive gases simultaneously due to diffusion, and this simultaneous exposure is not intentional.

[0027] In one aspect of a time-domain ALD process, a first reactive gas (i.e., a first precursor or compound A) is pulsed into a reaction zone, followed by a first time delay. Next, a second precursor or compound B is pulsed into the reaction zone, followed by a second delay. During each time delay, a purge gas (such as argon) is introduced into the processing chamber to purge the reaction zone or otherwise remove any residual reactive compounds or reaction byproducts 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, the ALD process of pulsing compound A, purge gas, compound B, and purge gas is a cycle. The cycle may start with compound A or compound B, and the cycle with the corresponding sequence is continued until a film with a predetermined thickness is obtained.

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

[0029] Embodiments of the present disclosure advantageously provide methods for substantially improving the resistivity of a blanket molybdenum film deposited on an underlying tungsten or molybdenum layer formed by the methods described in the present disclosure. One or more embodiments provide methods in which a continuous heat treatment is used to replace silicon from an amorphous silicon layer on a dielectric to form a metal layer comprising metal or tungsten. In one or more embodiments, a continuous treatment is performed for a period of time to form a metal layer, the continuous treatment having a predetermined treatment without repeating a heat soak treatment for forming the metal layer. In one or more embodiments, the metal layer formed on the dielectric by replacing the 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. Although not wishing to be bound by any particular theory or principle, it is believed that the continuous treatment without repetition leads to an improvement in the reduction of the stack resistivity of the molybdenum film formed on the metal layer. Further embodiments advantageously provide methods for reducing the stack resistivity of bottom-up gap filling for vias using improved molybdenum film properties.

[0030] Embodiments of the present disclosure are described by way of drawings, which illustrate devices (e.g., transistors) and processes for forming transistors according to one or more embodiments of the present disclosure. The processes shown are merely illustrative of possible uses of the disclosed processes, and those skilled in the art will recognize that the disclosed processes are not limited to the applications shown.

[0031] Figure 1 A process flow diagram of a deposition method 100 according to one or more embodiments of the present disclosure is depicted. At operation 110, the deposition method 100 includes directly forming an amorphous silicon layer on a dielectric surface (e.g., on a dielectric layer on a substrate, on a dielectric region of a substrate). At operation 120, the deposition method 100 includes converting the amorphous silicon layer into a metal layer by heat-soaking the amorphous silicon layer including silicon atoms in the presence of a metal compound selected from the group consisting of a molybdenum compound and a tungsten compound until at least a portion of the silicon atoms in the amorphous silicon layer are replaced by one or more metal atoms present during the treatment of heat-soaking the amorphous silicon layer. At operation 130, the deposition method 100 includes conformally depositing a molybdenum film on the metal layer.

[0032] The substrate 202 may be any suitable substrate material. In one or more embodiments, the substrate 202 includes a semiconductor material, such as silicon (Si), carbon (C), germanium (Ge), silicon germanium (SiGe), gallium arsenide (GaAs), indium phosphide (InP), indium gallium arsenide (InGaAs), indium aluminum arsenide (InAlAs), germanium (Ge), silicon germanium (SiGe), other semiconductor materials, or any combination thereof. In one or more embodiments, the substrate 400 includes one or more of silicon (Si), germanium (Ge), gallium (Ga), arsenic (As), indium (In), phosphorus (P), or selenium (Se). Although several examples of materials from which the substrate 202 is made have been provided, any material that can be used as a base having passive and active electronic devices (e.g., transistors, memories, capacitors, inductors, resistors, switches, integrated circuits, amplifiers, optoelectronic devices, or any other electronic devices) thereon may be utilized.

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

[0034] The deposition process used to deposit the molybdenum film is a deposition process capable of forming a continuous thin film over a large substrate area. One or more embodiments provide a process in which the deposition process is optimized to produce a low resistivity molybdenum film.

[0035] FIG. 2A to FIG. 2D Depicts a cross-sectional view of a deposition process on a substrate that produces a low resistivity film on a dielectric layer in accordance with one or more embodiments. Figure 2A , illustrates a substrate 2A having a surface such as a top surface 203 and a dielectric layer 204 on the top surface 203. Figure 2B In one or more embodiments, the deposition method includes forming an amorphous silicon layer 206 directly on the dielectric layer 204 on the top surface 203 of the substrate 202 .

[0036] See also Figure 2CThe method according to one or more embodiments further includes converting the amorphous silicon layer 206 into the metal layer 208 by heat-immersing the amorphous silicon layer 206 including silicon atoms for a period of time in the presence of a metal compound selected from a 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 a group consisting of molybdenum atoms and tungsten atoms, to form a metal layer 208 having a thickness in a range from 10 angstroms to 50 angstroms, or any thickness described herein.

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

[0038] In one or more embodiments, the metal layer 208 is formed by heat-soaking the amorphous silicon in a single step that is not repeated. In other words, the heat-soaking process is a continuous process that is performed for a period of time to obtain a predetermined thickness.

[0039] In some embodiments, dielectric layer 204 includes silicon oxide (SiO x )、Silicon Nitride(SiN x )、Silicon Carbide(SiC x ), Silicon Carbide Nitride (SiC x N y ), silicon oxynitride (SiO x N y ), a low dielectric constant dielectric material, or a combination thereof. In some embodiments, the step of forming the amorphous silicon layer 206 includes exposing the substrate surface having the dielectric layer 204 to silane (SiH4), disilane (Si2H6), or trisilane (Si3H8).

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

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

[0042] In one or more embodiments, conformally depositing the molybdenum film 210 includes one or more of atomic layer deposition (ALD), co-flowing a molybdenum precursor and hydrogen (H 2 ), or chemical vapor deposition (CVD).

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

[0044] Advantageously, a conformally deposited molybdenum film on a metal layer has a resistivity that is at least 30% reduced compared to a titanium nitride (TiN) film on which the conformally deposited molybdenum film is deposited. Experiments have shown that this improvement can be achieved for films with thicknesses ranging from 100 microns to 120 microns.

[0045] Another aspect of the present disclosure relates to a method as part of a gap fill process. Thus, a 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, see Figure 3A , the substrate contains

[0046] See also FIG. 3A to FIG. 3E, a method of filling a feature 300 formed on a top surface 303 of a substrate 302 is shown with respect to a feature 300 having a gap including opposing sidewalls 320 and a bottom surface 330. The substrate 302 may include the substrate 302 described above with respect to FIG. 2A to FIG. 2D Any of the non-limiting materials described. In the illustrated embodiment, substrate 302 is a dielectric region.

[0047] In one or more embodiments, see Figure 3B , the method of filling feature 300 includes directly forming an amorphous silicon layer 304 on a dielectric region, wherein the dielectric region includes a top surface 303 within the feature 300 on the surface of a substrate 302, and the feature 300 includes at least one surface defining a through hole, wherein the through hole includes a bottom surface 330 containing a dielectric and two opposing sidewalls 320.

[0048] See also Figure 3C The method further comprises replacing the amorphous silicon layer comprising silicon atoms by heat-immersing the amorphous silicon layer 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. Figure 3B The amorphous silicon layer 304 is shown converted into a metal layer 306 . Figure 3D The metal layer 308 is illustrated after complete conversion.

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

[0050] See also Figure 3E The method includes conformally depositing a molybdenum film 310 on the metal layer 308 to fill the feature 300, the conformally deposited molybdenum film 310 having substantially no gaps or voids.

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

[0052] Conformally depositing the molybdenum film includes one or more of atomic layer deposition (ALD), co-flowing a molybdenum precursor and hydrogen (H2), or chemical vapor deposition (CVD). The molybdenum precursor in the conformal film deposition of one or more embodiments includes one or more of molybdenum pentachloride (MoCl5), molybdenum oxychloride tetrachloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6).

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

[0054] In some embodiments, conformally depositing a molybdenum film is performed at a temperature in a range of 300° C. to 600° C. and at a pressure in a range of 10 Torr to 300 Torr. The molybdenum precursor may be contained in ampoules or containers maintained at a temperature in a range of 30° C. to 150° C.

[0055] The accompanying drawings illustrate a substrate 302 having a single feature 300 for illustrative purposes; however, one skilled in the art will appreciate that there may be more than one feature 300. The shape of the feature 300 may be any suitable shape, including but not limited to a groove and a cylindrical through hole. As used in this regard, the term "feature" means any intentional surface irregularity. Suitable examples of features include but are not limited to grooves and through holes 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 groove or a through hole. In a specific embodiment, at least one feature 300 includes a through hole. In yet other embodiments, the terms "at least one feature 300" and "through hole 300" may be used interchangeably. The through hole 300 has a depth to the 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, the through hole 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.

[0056] In some embodiments, the processes of deposition method 100 are each performed in the same process chamber. In some embodiments, the processes of deposition method 100 are each performed in different process chambers. In some embodiments, the different process chambers are connected as part of a processing system. In some embodiments, the processes of deposition method 100 are performed without an intervening vacuum break.

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

[0058] In some embodiments, the molybdenum film 310 is laterally bounded by two opposing sidewalls 320 of at least one feature 300. As used in this regard, "laterally bounded" 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 over at least one feature 300. In some embodiments, the molybdenum film 310 fills the through-hole 300. As used in this regard, a film that "fills the through-hole" has a volume that occupies at least 95%, at least 98%, or at least 99% of the volume of the through-hole 300. In some embodiments, the film that fills the through-hole has a fill height in the range from 30 nm to 75 nm, including in the range from 40 nm to 60 nm.

[0059] Embodiments of the present disclosure advantageously provide a molybdenum film 310 having a reduced resistivity compared to a molybdenum film deposited by processes other than those described herein (e.g., deposition method 100). Embodiments of the present disclosure advantageously provide a molybdenum film 310 that is free of or substantially free of voids and seams. As used in this regard, "substantially free" means that, on an atomic basis, less than about 5% (including less than about 4%, less than about 3%, less than about 2%, less than about 1%, less than about 0.5%, and less than about 0.1%) of the total composition of the in-situ selectively deposited molybdenum film 430 contains voids and / or seams.

[0060] Without intending to be bound by theory, it is believed that continuous heat soak treatments without repeated treatments improve the quality of the deposited molybdenum film 310. In some embodiments, the molybdenum film 310 deposited by the methods described herein has a reduced resistivity compared to molybdenum films made by other processes.

[0061] References throughout this specification to "one embodiment," "certain embodiments," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present disclosure. Thus, the appearance of phrases such as "in one or more embodiments," "certain embodiments," "in an embodiment," or "in an embodiment" in various places throughout this specification does not necessarily refer 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.

[0062] Although the disclosure herein has been described with reference to specific embodiments, it will 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 may be made to the methods and apparatus of the disclosure without departing from the spirit and scope of the disclosure. Therefore, the disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. A deposition method comprising the following steps: forming an amorphous silicon layer directly on the dielectric layer on the surface of the substrate; converting the amorphous silicon layer into a metal layer by heat-immersing the amorphous silicon layer including 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; and A molybdenum film is conformally deposited on the metal layer.

2. The deposition method according to claim 1, wherein the dielectric comprises silicon oxide (SiO x )、Silicon Nitride(SiN x )、Silicon Carbide(SiC x ), Silicon Carbide Nitride (SiC x N y ), silicon oxynitride (SiO x N y ), low dielectric constant dielectric materials, or a combination of the above. 3 . The deposition method according to claim 1 , wherein the step of forming the amorphous silicon layer comprises: exposing the surface of the substrate to silane (SiH 4 ), disilane (Si 2 H 6 ), or trisilane (Si 3 H 8 ). 4 . The deposition method according to claim 3 , wherein the step of forming the amorphous silicon layer is performed at a temperature in a range of 300° C. to 600° C. and at a pressure in a range of from 10 Torr to 300 Torr.

5. The deposition method according to claim 1, wherein the tungsten compound is selected from the group consisting of: tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten oxytetrachloride (VI) (WOCl4), tungsten pentachloride (WCl5), and the molybdenum compound is selected from the group consisting of: molybdenum pentachloride (MoCl5), molybdenum oxytetrachloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6). 6 . The deposition method according to claim 5 , wherein the step of heat-soaking the amorphous silicon layer is performed at a temperature in a range of 300° C. to 600° C. and at a pressure in a range of from 10 Torr to 300 Torr.

7. The deposition method of claim 1, wherein the step of conformally depositing the molybdenum film comprises one or more of atomic layer deposition (ALD), co-flowing a molybdenum precursor and hydrogen (H2), or chemical vapor deposition (CVD). 8 . The deposition method according to claim 7 , wherein the molybdenum precursor comprises 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 ).

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

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

11. The deposition method according to claim 1, wherein the step of converting the amorphous silicon layer into the metal layer comprises: thermally soaking the amorphous silicon layer including silicon atoms in the presence of the molybdenum compound.

12. The deposition method of claim 1, wherein the step of converting the amorphous silicon layer into a metal layer comprises: thermally soaking the amorphous silicon layer including silicon atoms in the presence of the tungsten compound.

13. A method of filling a feature formed on a surface of a substrate, the method comprising: forming an amorphous silicon layer directly on a dielectric region within the feature on the surface of the substrate, the feature including at least one surface defining a via, the via including a bottom surface and two sidewalls containing the dielectric; converting the amorphous silicon layer into a metal layer by heat-immersing the amorphous silicon layer including 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; and A molybdenum film is conformally deposited on the metal layer to fill the features, the conformally deposited molybdenum film being substantially free of seams or voids.

14. The method of claim 13, wherein the thermal soaking comprises exposing the amorphous silicon layer to one or more of: tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), tungsten (VI) oxychloride (WOCl4), tungsten pentachloride (WCl5), molybdenum pentachloride (MoCl5), molybdenum oxychloride tetrachloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6).

15. The method of claim 13, wherein conformally depositing the molybdenum film comprises one or more of atomic layer deposition (ALD), co-flowing a molybdenum precursor and hydrogen (H2), or chemical vapor deposition (CVD).

16. The method of claim 15, wherein the molybdenum precursor comprises one or more of molybdenum pentachloride (MoCl5), molybdenum oxychloride tetrachloride (MoOCl4), molybdenum dioxide dichloride (MoO2Cl2), and molybdenum hexafluoride (MoF6).

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

18. The method of claim 13, wherein the molybdenum film is completely conformally deposited within the via.

19. The method of claim 13, wherein the step of converting the amorphous silicon layer into a metal layer comprises: thermally soaking the amorphous silicon layer comprising silicon atoms in the presence of the tungsten compound.

20. The method of claim 13, wherein the step of converting the amorphous silicon layer into a metal layer comprises: thermally soaking the amorphous silicon layer comprising silicon atoms in the presence of the molybdenum compound.

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