Gap filling method using catalyst deposition - Patent Application 20070122997

Abstract

A method for depositing a metal film is discussed. A metal film is formed on the bottom of a feature having a metal bottom and dielectric sidewalls. Formation of the metal film involves exposure to a metal precursor and an alkyl halide catalyst, and maintaining the substrate at a deposition temperature. The metal precursor has a decomposition temperature above the deposition temperature. The alkyl halide contains carbon and a halogen, and the halogen contains bromine or iodine.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE

[0002] Embodiments of the present disclosure generally relate to methods for depositing metal films. Some embodiments of the present disclosure are directed to methods for depositing metal films. Some embodiments of the present disclosure relate to selective deposition of metal films. Some embodiments of the present disclosure control deposition location and / or deposition rate through the use of plasma and / or thermal exposure conditions. [Background technology]

[0002] The semiconductor industry continues to pursue relentless device miniaturization driven by the need for high-performance mobility systems in emerging industries such as autonomous vehicles, virtual reality, and future mobile devices. To achieve this feat, new high-performance materials are needed to circumvent the inherent engineering, chemical, and physical challenges encountered in the rapid shrinking of features in microelectronic devices.

[0003] Ruthenium is a newly proposed material for integration due to its high melting point (ability to withstand high current densities), exceptional density, and ability to conduct electrical current. Ruthenium and ruthenium-containing thin films have attractive material and conduction properties. Ruthenium films have been proposed for applications ranging from front-end to back-end portions of semiconductor and microelectronic devices.

[0004] In theory, thin films of ruthenium should be deposited using thin film deposition techniques such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) due to their inherent ability to deposit materials precisely at high throughput.

[0005] Nevertheless, deposited ruthenium films often differ from bulk ruthenium materials. Depositing ruthenium films with high purity (>99 atomic % Ru), especially as gap-filling materials, presents particular challenges. Previous solutions utilizing oxygen reactants produced films that were rougher than the bulk material. Similarly, hydrogen reactants produced more impurities, requiring a subsequent annealing step for removal. Finally, plasma deposition processes have not been able to deposit gap-filling materials without creating seams and possibly damaging the underlying substrate.

[0006] Current technology involves filling structures with CVD or electrochemical plating (ECP) processes. CVD processes, where deposition occurs over the entire structure, typically result in voids forming as the film emerges due to roughness, leaving seams in the gaps. ECP processes are limited by size and by the existence of processes for the required materials.

[0007] Therefore, there is a need for methods and materials for depositing high purity, conformal ruthenium films as gap fills. There is also a need for methods and materials for depositing ruthenium films as gap fills without seams or voids.

[0008] Additionally, as semiconductor device designs evolve, precision material manufacturing in the semiconductor industry has entered an era of atomic-scale dimensions. At the atomic scale, where only tens of atoms matter, there is little margin for error. This unprecedented challenge requires new material processing techniques with atomic-level precision. However, increasing the complexity of the process flows required to fabricate atomic-scale devices can significantly reduce throughput and increase manufacturing costs.

[0009] Selective deposition techniques offer the potential for chemically selective atomic layer precision in patterning semiconductor films. Selective deposition also offers the potential for simpler process flows by eliminating lithography or other processes.

[0010] Selective deposition of materials can be achieved in a variety of ways. For example, some processes have inherent surface selectivity based on the chemistry of the surface. These processes are fairly uncommon and typically require surfaces with dramatically different surface energies, such as metals and dielectrics.

[0011] Therefore, there is a need for a method for selectively depositing metal films on metal surfaces over dielectric surfaces, or vice versa.

[0012] Additionally, current devices use tungsten films for memory and logic circuit applications. Tungsten film deposition is often performed at relatively high temperatures, which can be limited by the thermal budget of the device being formed. Tungsten films are often deposited using fluorine-containing compounds. Fluorine is generally undesirable in the deposition process due to potential reactions and adverse effects. To prevent the fluorine from reacting with underlying layers, relatively thick barrier layers are used. Deposition of the barrier layer reduces the thermal budget and throughput.

[0013] Therefore, there is a need in the art for conductive materials that are fluorine-free and / or can be deposited at low temperatures.

[0014] Additionally, during middle-of-line (MOL) processes, minimal via resistance is targeted for MOL structures. Often, a liner material is required to improve the adhesion of metal (e.g., ruthenium) to the dielectric material to eliminate post-processing steps such as chemical mechanical planarization (CMP). However, the presence of the liner increases the via resistance. Therefore, there is a need in the art for a gap-fill process for MOL that reduces via resistance. Summary of the Invention

[0015] One or more embodiments of the present disclosure are directed to a metal deposition method. A substrate having at least one feature including a bottom and sidewalls is exposed to alternating pulses of a metal precursor and an alkyl halide catalyst. The substrate is maintained at a deposition temperature to form a metal film on the bottom of the feature. The bottom of the feature comprises a metal and the sidewalls of the feature comprise a dielectric. The metal precursor has a decomposition temperature above the deposition temperature. The alkyl halide comprises carbon and a halogen, the halogen comprising bromine or iodine.

[0016] An additional embodiment of the present disclosure is directed to a method of forming a seamless gapfill. A second metal film is deposited within a feature on a substrate to partially fill the feature with the second metal film. The feature includes a bottom and at least one sidewall. The bottom includes a first metal and at least one sidewall includes a dielectric. The second metal film is selectively formed on the bottom relative to the at least one sidewall and has a top surface below a top surface of the dielectric. A liner is deposited on the sidewall of the feature to extend above the second metal film. The feature is filled with the second metal film to cover the liner and the top surface of the dielectric. At least a portion of the second metal film and liner is removed from the top surface of the dielectric and from at least a portion of the dielectric to form a seamless gapfill.

[0017] A further embodiment of the present disclosure is directed to a method for forming a seamless gapfill, the method including: (a) optionally cleaning a surface of a first metal at a bottom of a feature in a substrate, the feature including at least one dielectric sidewall; (b) selectively depositing a ruthenium film in the feature on the first metal relative to the dielectric sidewalls, the ruthenium film partially filling the feature such that a top surface of the ruthenium film is below a top surface of the dielectric; (c) optionally selectively forming a blocking layer on the top surface of the ruthenium film; and (d) depositing a ruthenium film on the dielectric sidewalls and the top surface of the dielectric. (e) optionally removing the blocking layer from the top surface of the ruthenium film; (f) filling the feature with a ruthenium film to cover the dielectric sidewalls and the conformal liner on the top surface of the dielectric; (g) annealing the ruthenium film; and (h) removing a portion of the ruthenium film and the dielectric, and at least a portion of the liner to form a seamless ruthenium gap fill.

[0018] So that the above-mentioned features of the present disclosure can be understood in detail, a more particular description of the present disclosure briefly summarized above can be had by reference to embodiments, some of which are illustrated in the accompanying drawings. It should be noted, however, that the present disclosure is also susceptible to 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. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram of a processing platform according to one or more embodiments of the present disclosure. [Figure 2] FIG. 1 is a cross-sectional view of a batch processing chamber according to one or more embodiments of the present disclosure. [Figure 3] FIG. 1 is a partial perspective view of a batch processing chamber according to one or more embodiments of the present disclosure. [Figure 4]FIG. 1 is a schematic diagram of a batch processing chamber according to one or more embodiments of the present disclosure. [Figure 5] FIG. 1 is a schematic diagram of a portion of a wedge-shaped gas distribution assembly for use in a batch processing chamber in accordance with one or more embodiments of the present disclosure. [Figure 6] FIG. 1 is a schematic diagram of a batch processing chamber according to one or more embodiments of the present disclosure. [Figure 7] FIG. 1 illustrates an exemplary process sequence for forming a metal layer using a two-pulse cyclic deposition technique in accordance with one or more embodiments of the present disclosure. [Figure 8] 1A-1C illustrate an exemplary process sequence for the formation of a ruthenium layer in accordance with one or more embodiments of the present disclosure. [Figure 9] 1 is a cross-sectional view of an exemplary substrate according to one or more embodiments of the present disclosure. [Figures 10A-10D] 1A-1D illustrate an exemplary substrate during processing in accordance with one or more embodiments of the present disclosure. [Figure 11] 1A-1D illustrate an exemplary method for seamless gap filling according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0020] In the accompanying figures, similar components and / or features may have the same reference label. Furthermore, various components of the same type may be distinguished by a dash following the reference label and a second label that distinguishes the similar components. When only a first reference label is used herein, the description is applicable to any of the similar components having the same first reference label, regardless of the second reference label.

[0021] Before describing several exemplary embodiments of the present disclosure, it is to be understood that the present disclosure is not limited to the details of structure or process routines set forth in the following description, as the present disclosure is capable of other embodiments and of being practiced or being carried out in various ways.

[0022] As used herein, "substrate," "substrate surface," and the like refer to any substrate or material surface formed on a substrate on which processing is performed. For example, substrate surfaces on which processing can be performed include, but are not limited to, materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, silicon nitride, 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. Substrates include, but are not limited to, semiconductor wafers. Substrates can be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate (or otherwise create or implant targeted chemical moieties to impart chemical functionality), anneal, and / or bake the substrate surface. In addition to direct processing of the surface of the substrate itself, the present disclosure also contemplates performing any of the disclosed film processing steps on underlying layers formed on the substrate, as disclosed in more detail below, and the term "substrate surface" is intended to include such underlying layers as the context indicates. Thus, for example, if a film / layer or partial film / layer is being deposited onto a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface. What a given substrate surface comprises depends on the material being deposited as well as the particular chemistry used.

[0023] As used herein, "atomic layer deposition" or "cyclic deposition" refers to depositing a layer of material on a substrate surface by sequential exposure to two or more reactive compounds. In this specification and the appended claims, terms such as "reactive compound," "reactive gas," "reactive species," "precursor," and "process gas" are used interchangeably to refer to substances having species capable of reacting with the substrate surface or materials on the substrate surface in surface reactions (e.g., chemisorption, oxidation, reduction). 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 considered 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 such that any given point on the substrate is not substantially simultaneously exposed to two or more reactive compounds. As used herein and in the appended claims, the term "substantially" as used in this regard means that a small portion of the substrate may be exposed to multiple reactive gases simultaneously due to diffusion, and that this simultaneous exposure is not intended, as will be understood by those skilled in the art.

[0024] In one aspect of a time-domain ALD process, a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, followed by a first time delay. Then, 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 compound or reaction by-products from the reaction zone. Alternatively, the purge gas can flow continuously throughout the deposition process, thus flowing only during the time delay between pulses of reactive compound. Alternatively, the reactive compound is 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 cyclic. The cycle can be initiated with either compound A or compound B, and each sequence of cycles can be continued until a film having a predetermined thickness is achieved.

[0025] In one embodiment of a spatial ALD process, a first reactive gas and a second reactive gas (e.g., a metal precursor gas) are simultaneously delivered to a reaction zone but separated by an inert gas curtain and / or a vacuum curtain, and the substrate is moved relative to the gas delivery device so that any given point on the substrate is exposed to the first reactive gas and the second reactive gas.

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

[0027] Some embodiments of the present disclosure are directed to processes using a reaction chamber with multiple gas ports that can be used for the introduction of different chemical or plasma gases. Spatially, these gas ports (also called channels) are separated by inert purge gas and / or vacuum pumping holes to create a gas curtain that minimizes or eliminates mixing of gases from different gas ports to avoid undesired gas-phase reactions. Wafers passing through these different spatially separated ports receive sequential multi-side exposure to different chemical or plasma environments, thus resulting in layer-by-layer film growth in spatial ALD mode or surface etching processes. In some embodiments, the processing chamber has a modular architecture on the gas distribution components, with each modular component having independent parameter control (e.g., RF or gas flow), providing flexibility for controlling, for example, gas flow and / or RF exposure.

[0028] Some embodiments of the present disclosure provide methods for depositing high-purity metal films. In various embodiment methods, atomic layer deposition (ALD) is used to provide pure or nearly pure metal films. While exemplary embodiments of the present disclosure refer to the deposition of ruthenium, it is believed that the principles of the present disclosure enable the deposition of highly pure metal films regardless of the metal.

[0029] Some embodiments of the present disclosure provide methods for selectively depositing a metal film on a metal surface over a dielectric surface. Some embodiments of the present disclosure provide methods for selectively depositing a metal film on a dielectric surface over a metal surface. As used herein and in the appended claims, terms such as "selectively depositing a film on one surface over another surface" mean that a first amount of film is deposited on the first surface and a second amount of film is deposited on the second surface, the amount of the second film being less than the amount of the first film, or no film is deposited on the second surface.

[0030] The term "over" as used in this context does not refer to the physical orientation of one surface over another, but rather to the relationship of the thermodynamic or kinetic properties of a chemical reaction of one surface to another. For example, preferential deposition of a metal film on a metal surface over a dielectric surface means that the metal film deposits on the metal surface and less or no metal film deposits on the dielectric surface, or that the formation of a metal film on a metal surface is thermodynamically or kinetically favored over the formation of a metal film on a dielectric surface.

[0031] The selectivity of a deposition process is generally expressed as a multiple of the growth rate. For example, if one surface grows (or deposits) 25 times faster than a different surface, the process would be described as having a selectivity of 25:1. In this context, a higher ratio indicates a more selective process.

[0032] Some embodiments of the present disclosure advantageously provide methods for depositing metal films having high purity. Accordingly, these highly pure films exhibit properties similar to the associated bulk metal materials. For example, some embodiments of the present disclosure provide ruthenium films that are smoother and have lower resistivity than ruthenium films deposited by conventional oxygen or hydrogen reactant processes. Some embodiments of the present disclosure advantageously provide metal films that seamlessly and conformally fill gaps.

[0033] Some embodiments of the present disclosure advantageously provide selective deposition of metal films with higher purity on metal surfaces than on dielectric surfaces. For example, selective deposition of metal (e.g., ruthenium) on copper over dielectrics advantageously provides a copper capping layer without additional etching or lithography steps. In addition, selective deposition can also enable bottom-up gap filling for features (e.g., trenches, vias) with metal contacts on the bottom and dielectric sidewalls.

[0034] Some embodiments of the present disclosure advantageously provide selective deposition of metal films having higher purity on dielectric surfaces than on metal surfaces. For example, selective deposition of metal over dielectrics is advantageous for providing metal layers over barriers or other dielectrics in back-end applications.

[0035] Some embodiments of the present disclosure utilize aerial ALD processes performed on a processing platform disclosed herein. Referring to these figures, FIG. 1 illustrates a processing platform 100 according to one or more embodiments of the present disclosure. The embodiment illustrated in FIG. 1 represents only one possible configuration and should not be considered limiting of the scope of the present disclosure. For example, in some embodiments, the processing platform 100 has different numbers of process chambers, buffer chambers, and robot configurations.

[0036] The processing platform 100 includes a central transfer station 110 having a number of sides 111, 112, 113, 114, 115, 116. The central transfer station 110 is shown having a first side 111, a second side 112, a third side 113, a fourth side 114, a fifth side 115, and a sixth side 116. While six sides are shown, those skilled in the art will understand that there can be any suitable number of sides for the central transfer station 110 depending, for example, on the overall configuration of the processing platform 100.

[0037] Positioned within transfer station 110 is robot 117. Robot 117 can be any suitable robot capable of moving wafers during processing. In some embodiments, robot 117 has a first arm 118 and a second arm 119. First arm 118 and second arm 119 can move independently of the other arm. First arm 118 and second arm 119 can move in the x-y plane and / or along the z-axis. In some embodiments, robot 117 includes a third arm or a fourth arm (not shown). Each of these arms can move independently of the other arms.

[0038] A first batch processing chamber 120 can be connected to the first side 111 of the central transfer station 110. The first batch processing chamber 120 can be configured to process x wafers at a time over a batch time. In some embodiments, the first batch processing chamber 120 can be configured to process between about four (x=4) and about twelve (x=12) wafers simultaneously. In some embodiments, the first batch processing chamber 120 is configured to process six (x=6) wafers simultaneously. As will be appreciated by those skilled in the art, the first batch processing chamber 120 can process multiple wafers between individual wafer loading / unloading, with each wafer being subjected to different process conditions at any given time. For example, a spatial atomic layer deposition chamber such as those shown in FIGS. 2-6 exposes wafers to different process conditions in different processing regions, thus completing the process as the wafers are moved through each of the regions.

[0039] 2 shows a cross-section of a processing chamber 200 including a gas distribution assembly 220, also referred to as an injector or injector assembly, and a susceptor assembly 240. The gas distribution assembly 220 is any type of gas delivery device used within a processing chamber. The gas distribution assembly 220 includes a front surface 221 that faces the susceptor assembly 240. The front surface 221 can have any number or variety of openings for delivering a flow of gas toward the susceptor assembly 240. The gas distribution assembly 220 also includes an outer periphery 224, which in the illustrated embodiment is substantially circular.

[0040] The specific type of gas distribution assembly 220 used can vary depending on the particular process being used. Embodiments of the present disclosure can be used with any type of processing system in which the gap between the susceptor and the gas distribution assembly is controlled. While various types of gas distribution assemblies (e.g., showerheads) can be used, embodiments of the present disclosure can be particularly useful in spatial gas distribution assemblies having multiple substantially parallel gas channels. As used herein and in the appended claims, the term "substantially parallel" means that the elongated axes of the gas channels extend in the same general direction. Minor imperfections in the parallelism of the gas channels are possible. In a binary reaction, the multiple substantially parallel gas channels can include at least one first reactive gas A channel, at least one second reactive gas B channel, at least one purge gas P channel, and / or at least one vacuum V channel. Gas flowing from the first reactive gas A channel, the second reactive gas B channel, and the purge gas P channel is directed toward the top surface of the wafer. A portion of the gas flow moves horizontally across the surface of the wafer and exits the process region through the purge gas P channel. A substrate moving from one end of the gas distribution assembly to the other is sequentially exposed to each of the process gases to form a layer on the substrate surface.

[0041] In some embodiments, the gas distribution assembly 220 is a rigid, stationary object made from a single injector unit. In one or more embodiments, the gas distribution assembly 220 is composed of multiple individual sections (e.g., injector units 222), as shown in Figure 3. Either a single object or a multi-section object can be used in various embodiments of the present disclosure described.

[0042] Positioned below the gas distribution assembly 220 is a susceptor assembly 240. The susceptor assembly 240 includes a top surface 241 and at least one recess 242 within the top surface 241. The susceptor assembly 240 also has a bottom surface 243 and an edge 244. The at least one recess 242 can be any suitable shape and size depending on the shape and size of the substrate 60 being processed. In the embodiment shown in FIG. 2, the recess 242 has a flat bottom to support the bottom of the wafer, although the bottom of the recess can vary. In some embodiments, the recess has a stepped region around its outer periphery sized to support the outer edge of the wafer. The amount of the wafer's outer edge supported by the steps can vary depending, for example, on the wafer thickness and the presence of pre-existing features on the backside of the wafer.

[0043] 2, the recess 242 in the top surface 241 of the susceptor assembly 240 is sized so that the top surface 61 of the substrate 60 supported in the recess 242 is substantially coplanar with the top surface 241 of the susceptor 240. As used herein and in the appended claims, the term "substantially coplanar" means that the top surface of the wafer and the top surface of the susceptor assembly are coplanar within ±0.2 mm. In some embodiments, the top surfaces are coplanar within 0.5 mm, ±0.4 mm, ±0.35 mm, ±0.30 mm, ±0.25 mm, ±0.20 mm, ±0.15 mm, ±0.10 mm, or ±0.05 mm.

[0044] 2 includes a support post 260 that can raise, lower, and rotate the susceptor assembly 240. The susceptor assembly may include a heater or gas line or electrical components in the center of the support post 260. The support post 260 may be the primary means for increasing or decreasing the gap between the susceptor assembly 240 and the gas distribution assembly 220 to move the susceptor assembly 240 into the appropriate position. The susceptor assembly 240 may also include a fine adjustment actuator 262 that can apply fine adjustments to the susceptor assembly 240 to create a predetermined gap 270 between the susceptor assembly 240 and the gas distribution assembly 220.

[0045] In some embodiments, the distance of gap 270 is in the range of about 0.1 mm to about 5.0 mm, or in the range of about 0.1 mm to about 3.0 mm, or in the range of about 0.1 mm to about 2.0 mm, or in the range of about 0.2 mm to about 1.8 mm, or in the range of about 0.3 mm to about 1.7 mm, or in the range of about 0.4 mm to about 1.6 mm, or in the range of about 0.5 mm to about 1.5 mm, or in the range of about 0.6 mm to about 1.4 mm, or in the range of about 0.7 mm to about 1.3 mm, or in the range of about 0.8 mm to about 1.2 mm, or in the range of about 0.9 mm to about 1.1 mm, or about 1 mm.

[0046] The processing chamber 200 shown in these figures is a carousel-type chamber in which the susceptor assembly 240 can hold multiple substrates 60. As shown in FIG. 3 , the gas distribution assembly 220 can include multiple separate injector units 222, each capable of depositing a film on a wafer as the wafer is moved beneath the injector unit. Two pie-shaped injector units 222 are shown positioned above the susceptor assembly 240 on generally opposite sides of the susceptor assembly 240. This number of injector units 222 is shown for illustrative purposes only. It will be understood that more or fewer injector units 222 can be included. In some embodiments, there are a sufficient number of pie-shaped injector units 222 to form a shape that conforms to the shape of the susceptor assembly 240. In some embodiments, each of the individual pie-shaped injector units 222 can be independently moved, removed, and / or replaced without affecting any of the other injector units 222. For example, one section can be lifted to allow a robot to access the area between the susceptor assembly 240 and the gas distribution assembly 220 for loading / unloading the substrate 60 .

[0047] A processing chamber with multiple gas injectors can be used to process multiple wafers simultaneously so that the wafers receive the same process flow. For example, as shown in FIG. 4, processing chamber 200 has four gas injector assemblies and four substrates 60. At the beginning of processing, substrates 60 can be positioned between gas distribution assemblies 220. Rotating susceptor assembly 240 45° (17) moves each substrate 60 between the gas distribution assemblies 220 toward the gas distribution assemblies 220 for film deposition, as indicated by the dotted circles below the gas distribution assemblies 220. Rotating another 45° moves the substrate 60 away from the gas distribution assemblies 220. The number of substrates 60 and gas distribution assemblies 220 can be the same or different. In some embodiments, the same number of wafers are processed as there are gas distribution assemblies. In one or more embodiments, the number of wafers being processed is a fraction or integer multiple of the number of gas distribution assemblies. For example, if there are four gas distribution assemblies, 4x wafers are being processed, where x is an integer value greater than or equal to 1. In an exemplary embodiment, the gas distribution assembly 220 includes eight process regions separated by gas curtains, and the susceptor assembly 240 is capable of holding six wafers.

[0048] The processing chamber 200 shown in FIG. 4 represents only one possible configuration and should not be considered limiting of the scope of the present disclosure. Here, the processing chamber 200 includes multiple gas distribution assemblies 220. In the embodiment shown, four gas distribution assemblies 220 (also referred to as injector assemblies) are evenly spaced around the processing chamber 200. While the processing chamber 200 shown is octagonal, those skilled in the art will understand that this is only one possible shape and should not be considered limiting of the scope of the present disclosure. While the gas distribution assembly 220 shown is trapezoidal, it could also be a single circular component or could be composed of multiple pie-shaped sections, as shown in FIG. 3.

[0049] 4 includes an auxiliary chamber, such as a load lock chamber 280, or buffer station, connected to one side of the processing chamber 200 to allow for loading / unloading of substrates (also referred to as substrates 60) in the processing chamber 200. A wafer robot can be positioned within the chamber 280 to move the substrate onto the susceptor.

[0050] Rotation of the carousel (e.g., susceptor assembly 240) can be continuous or intermittent (discontinuous). For continuous processing, the wafer rotates constantly and is therefore exposed to each of the injectors in turn. For discontinuous processing, the wafer can be moved to an injector area, stopped, and then moved to the inter-injector area 84 and stopped. For example, the carousel can rotate such that the wafer moves from the inter-injector area across the injector (or stops near the injector), advances onto the next inter-injector area, where the carousel can pause again. Pausing between injectors can provide time for additional processing routines (e.g., exposure to plasma) between each layer deposition.

[0051] FIG. 5 illustrates a section or portion of a gas distribution assembly 220 that can be referred to as an injector unit. The injector units 222 can be used individually or in combination with other injector units. For example, as shown in FIG. 6, four of the injector units 222 of FIG. 5 are combined to form a single gas distribution assembly 220 (for clarity, the lines separating the four injector units are not shown). The injector unit 222 of FIG. 5 has both a first reactive gas port 225 and a second gas port 235, in addition to a purge gas port 255 and a vacuum port 245, although not all of these components are required for the injector unit 222.

[0052] 5 and 6 , a gas distribution assembly 220 according to one or more embodiments can include multiple zones (or injector units 222), each of which can be the same or different. The gas distribution assembly 220 is positioned within the processing chamber and includes multiple elongated gas ports 225, 235, 245 on a front surface 221 of the gas distribution assembly 220. The multiple elongated gas ports 225, 235, 245, 255 extend from a zone adjacent the inner periphery 223 toward a zone adjacent the outer periphery 224 of the gas distribution assembly 220. The multiple gas ports shown include a first reactive gas port 225, a second gas port 235, a vacuum port 245 surrounding each of the first and second reactive gas ports, and a purge gas port 255.

[0053] 5 or 6, starting therefrom, the ports extend from at least approximately the inner circumferential region to at least approximately the outer circumferential region, although the ports can also extend more than radially from the inner region to the outer region. The ports can extend tangentially when the vacuum port 245 surrounds the reactive gas ports 225 and 235. In the embodiments shown in FIGS. 5 and 6, the wedge-shaped reactive gas ports 225, 235 are surrounded on all edges, including near the inner and outer circumferential regions, by the vacuum port 245.

[0054] Referring to FIG. 5, as the substrate moves along path 227, portions of the substrate surface are exposed to various reactive gases. As the substrate follows path 227, it is exposed to or "sees" purge gas port 255, vacuum port 245, first reactive gas port 225, vacuum port 245, purge gas port 255, vacuum port 245, second gas port 235, and vacuum port 245. Thus, at the end of path 227 shown in FIG. 5, the substrate is exposed to the first reactive gas and the second reactive gas to form a layer. The injector units 222 shown form a quarter circle, but could be larger or smaller. The gas distribution assembly 220 shown in FIG. 6 can be considered a combination of four of the injector units 222 of FIG. 3 connected in series.

[0055] The injector unit 222 in FIG. 5 shows a gas curtain 250 that separates the reactive gases. The term "gas curtain" is used to describe any combination of gas flow or vacuum that separates reactive gases so they do not mix. The gas curtain 250 shown in FIG. 5 includes a portion of the vacuum port 245 adjacent to the first reactive gas port 225, a central purge gas port 255, and a portion of the vacuum port 245 adjacent to the second gas port 235. This combination of gas flow and vacuum can be used to prevent or minimize gas-phase reactions of the first reactive gas and the second reactive gas.

[0056] Referring to Figure 6, the combination of gas flow and vacuum from the gas distribution assembly 220 creates separation into multiple process regions 350. The process regions are roughly defined around individual gas ports 225, 235 with gas curtains 250 located between them. The embodiment shown in Figure 6 defines eight separate process regions 350 with eight separate gas curtains 250 located therebetween. A processing chamber can have at least two process regions. In some embodiments, there are at least three, four, five, six, seven, eight, nine, ten, eleven, or twelve process regions.

[0057] During processing, a substrate can be exposed to more than one process region 350 at any given time. However, portions exposed to different process regions have gas curtains separating the two. For example, when the leading edge of the substrate enters the process region containing the second gas port 235, a central portion of the substrate falls under the gas curtain 250, and the trailing edge of the substrate is located in the process region containing the first reactive gas port 225.

[0058] A factory interface (shown in FIG. 4) connected to the processing chamber 200 is shown and can be, for example, a load lock chamber 280. To provide a frame of reference, a substrate 60 is shown stacked on the gas distribution assembly 220. The substrate 60 can often be located on a susceptor assembly so that it is held near the front surface 221 of the gas distribution assembly 220. The substrate 60 is loaded onto a substrate support or susceptor assembly (see FIG. 4) within the processing chamber 200 via the factory interface. The substrate is positioned adjacent to the first reactive gas port 225 and between two gas curtains 250 a, 250 b, thereby illustrating the substrate 60 positioned within a processing region. Rotating the substrate 60 along path 227 moves the substrate counterclockwise around the processing chamber 200. Thus, the substrate 60 is exposed to the first through eighth processing regions 350 a through 350 h, including all processing regions in between.

[0059] Some embodiments of the present disclosure are directed to a processing chamber 200 having multiple process regions 350a-350h, such as the processing chamber shown in FIG. 6, where each process region is separated from an adjacent region by a gas curtain 250. The number of gas curtains and process regions within a processing chamber can be any suitable number depending on the gas flow arrangement. The embodiment shown in FIG. 6 has eight gas curtains 250 and eight process regions 350a-350h.

[0060] 1 , the processing platform 100 includes a processing chamber 140 connected to a second side 112 of the central transfer station 110. The processing chamber 140 in some embodiments is configured to expose wafers to a process for processing the wafers before and / or after processing in the first batch processing chamber 120. In some embodiments, the processing chamber 140 comprises an annealing chamber. The annealing chamber can be a furnace annealing chamber or a rapid thermal annealing chamber, or a different chamber configured to hold the wafers at a predetermined temperature and pressure and provide a flow of gas to the chamber.

[0061] In some embodiments, the processing platform further comprises a second batch processing chamber 130 connected to a third side 113 of the central transfer station 110. The second batch processing chamber 130 can be configured similarly to the first batch processing chamber 120, or can be configured to perform a different process or process a different number of substrates.

[0062] The second batch processing chamber 130 can be the same as or different from the first batch processing chamber 120. In some embodiments, the first batch processing chamber 120 and the second batch processing chamber 130 are configured to perform the same process on the same number of wafers in the same batch time, such that x (the number of wafers in the first batch processing chamber 120) and y (the number of wafers in the second batch processing chamber 130) are the same and the first batch time and the second batch time (second batch processing chamber 130) are the same. In some embodiments, the first batch processing chamber 120 and the second batch processing chamber 130 are configured to have one or more of different wafer numbers (x is not equal to y), different batch times, or both.

[0063] 1, the processing platform 100 includes a second processing chamber 150 connected to the fourth side 114 of the central transfer station 110. The second processing chamber 150 can be the same as or different from the processing chamber 140.

[0064] The processing platform 100 may include a controller 195 connected to the robot 117 (connection not shown). The controller 195 may be configured to move wafers between the processing chamber 140 and the first batch processing chamber 120 via a first arm 118 of the robot 117. In some embodiments, the controller 195 is also configured to move wafers between the second processing chamber 150 and the second batch processing chamber 130 via a second arm 119 of the robot 117.

[0065] In some embodiments, the controller 195 is connected to the susceptor assembly 240 and the gas distribution assembly 220 of the processing chamber 200. The controller 195 can be configured to rotate (17) the susceptor assembly 240 about a central axis. The controller can also be configured to control gas flow in the gas ports 225, 235, 245, and 255. In some embodiments, the first reactive gas port 225 provides a flow of a metal precursor. In some embodiments, the second reactive gas port 235 provides a flow of a reactant. In some embodiments, other gas ports (not labeled) can provide a flow of plasma. The first reactive gas port 225, the second reactive gas port 235, and other reactive gas ports (not labeled) can be arranged in any processing order.

[0066] The processing platform 100 may also include a first buffer station 151 connected to a fifth side 115 of the central transfer station 110 and / or a second buffer station 152 connected to a sixth side 116 of the central transfer station 110. The first buffer station 151 and the second buffer station 152 may perform the same or different functions. For example, the buffer stations may hold cassettes of wafers, which are processed and returned to the original cassette, or the first buffer station 151 may hold unprocessed wafers, which are moved to the second buffer station 152 after processing. In some embodiments, one or more of the buffer stations are configured to pre-process, pre-heat, or clean wafers before and / or after processing.

[0067] In some embodiments, the controller 195 is configured to use the first arm 118 of the robot 117 to move wafers between the first buffer station 151 and one or more of the processing chamber 140 and the first batch processing chamber 120. In some embodiments, the controller 195 is configured to use the second arm 119 of the robot 117 to move wafers between the second buffer station 152 and one or more of the second processing chamber 150 or the second batch processing chamber 130.

[0068] The processing platform 100 may also include one or more slit valves 160 between the central transfer station 110 and any of the processing chambers. In the embodiment shown, there is a slit valve 160 between each of the processing chambers 120, 130, 140, 150 and the central transfer station 110. The slit valves 160 can be opened and closed to separate the environment in the processing chamber from the environment in the central transfer station 110. For example, if a processing chamber generates plasma during processing, it may be useful to close the slit valve for that processing chamber to prevent stray plasma from damaging a robot in the transfer station.

[0069] In some embodiments, the processing chambers are not easily removable from the central transfer station 110. To allow maintenance to be performed on any of the processing chambers, each of the processing chambers may further include multiple access doors 170 on the sides of the processing chamber. The access doors 170 allow manual access to the processing chamber without removing the processing chamber from the central transfer station 110. In the embodiment shown, each side of each of the processing chambers has an access door 170, except for the side connected to the transfer station. Including so many access doors 170 can complicate the design of the processing chambers used, as it must be possible to configure the hardware within the chambers to be accessible through the doors.

[0070] The processing platform of some embodiments includes a water box 180 connected to the central transfer station 110. The water box 180 can be configured to provide coolant to any or all of the processing chambers. Although referred to as a "water" box, those skilled in the art will understand that any coolant can be used.

[0071] In some embodiments, the size of the processing platform 100 allows connection to store electrical power via a single power connector 190. The single power connector 190 is attached to the processing platform 100 to provide electrical power to each of the processing chambers and the central transfer station 110.

[0072] The processing platform 100 can be connected to a factory interface 102 to allow wafers or cassettes of wafers to be loaded into the processing platform 100. A robot 103 in the factory interface 102 can move wafers or cassettes into and out of buffer stations 151, 152. The wafers or cassettes can be moved within the processing platform 100 by a robot 117 in a central transfer station 110. In some embodiments, the factory interface 102 is the transfer station of another cluster tool.

[0073] In some embodiments, the processing platform 100 or the first batch processing chamber 120 is connected to a controller. The controller can be the same controller 195 or a different controller. The controller can be coupled to the susceptor assembly and gas distribution assembly of the first batch processing chamber 120 and can have one or more configurations. These configurations can include, but are not limited to, a first configuration for rotating the susceptor assembly about a central axis, a second configuration for providing a flow of a metal precursor to the process region, a third configuration for providing a flow of a reactant to the process region, and a fourth configuration for providing a plasma in the process region.

[0074] 7 illustrates a generalized method for forming a metal film on a substrate according to one or more embodiments of the present disclosure. Method 700 generally begins at 702, where a substrate on which a metal film is to be formed is provided and placed into a processing chamber. As used herein, "substrate surface" refers to any substrate surface upon which a layer can be formed. The substrate surface can have one or more features formed therein, one or more layers formed on the substrate surface, and combinations thereof. The substrate (or substrate surface) can be pretreated prior to deposition of the metal film by, for example, polishing, etching, reducing, oxidizing, halogenating, hydroxylating, annealing, baking, etc.

[0075] The substrate can be any substrate upon which a material can be deposited, such as a silicon substrate, a III-V compound substrate, a silicon germanium (SiGe) substrate, an epitaxial substrate, a silicon-on-insulator (SOI) substrate, a display substrate such as a liquid crystal display (LCD), a plasma display, or an electroluminescent (EL) lamp display, a solar cell array, a solar panel, a light-emitting diode (LED) substrate, or a semiconductor wafer. In some embodiments, one or more additional layers can be disposed on the substrate, and a metal film can be at least partially formed on the additional layers. For example, in some embodiments, a layer including a metal, nitride, oxide, or the like, or a combination thereof, can be disposed on the substrate, and a metal film can be formed on such one or more layers.

[0076] At 703, the substrate is optionally exposed to a blocking compound. This process step is described in more detail below and can be useful for controlling the selectivity of the deposition process on substrates containing both metal and dielectric surfaces.

[0077] At 704, a metal film is formed on the substrate. The metal film can be formed via a cyclic deposition process, such as atomic layer deposition (ALD). In some embodiments, forming a metal film via a cyclic deposition process generally can include separately exposing the substrate to two or more process gases. In time-domain ALD embodiments, exposure to each of the process gases is separated by a time delay / pause to allow components of the process gas to adhere to and / or react with the substrate surface. Alternatively, or in combination, in some embodiments, purging can be performed before and / or after exposure of the substrate to the process gases, and an inert gas is used to perform this purging. For example, a first process gas can be provided to the process chamber, followed by a purge with an inert gas. Then, a second process gas can be provided to the process chamber, followed by a purge with an inert gas. In some embodiments, the inert gas can be provided sequentially to the process chamber, and a first process gas can be dispensed or pulsed into the process chamber, followed by a second process gas being dispensed or pulsed into the process chamber. In such embodiments, the continuous flow of inert gas can create a delay or pause between the dispensing of the first process gas and the dispensing of the second process gas to allow for purging of the process chamber between the dispensing of the process gases.

[0078] In spatial ALD embodiments, exposure to each of the process gases occurs simultaneously on different portions of the substrate, so that one portion of the substrate is exposed to a first reactive gas while a different portion of the substrate is exposed to a second reactive gas (if only two reactive gases are used). The substrate is moved relative to the gas delivery system so that each point on the substrate is sequentially exposed to both the first and second reactive gases. In either time-domain or spatial ALD process embodiments, this sequence can be repeated until a predetermined layer thickness is formed on the substrate surface.

[0079] As used herein, "pulse" or "dose" is intended to refer to an amount of source gas that is intermittently or discontinuously introduced into a process chamber. The amount of a particular compound in each pulse can vary over time, depending on the duration of the pulse. A particular process gas can include a single compound or a mixture / combination of two or more compounds, such as the process gases described below.

[0080] The duration of each pulse / dosage is variable and can be adjusted to accommodate, for example, the volumetric capacity of the processing chamber and the capabilities of the vacuum system coupled to the processing chamber. In addition, the process gas dosage time can vary according to the flow rate of the process gas, the temperature of the process gas, the type of control valve, the type of process chamber used, and the ability of the process gas components to adsorb to the substrate surface. The dosage time can also vary based on the type of layer being formed and the geometry of the device being formed. The dosage time must be long enough to provide a volume of compound sufficient to adsorb / chemisorb onto substantially the entire surface of the substrate and form a layer of the process gas components on the substrate.

[0081] The process of forming a metal film at 704 can begin by exposing the substrate to a first reactive gas, which includes an alkyl halide, and is exposed to the substrate for a first period of time, as shown at 706.

[0082] The alkyl halide can be any reactant suitable for adsorption to a halogen layer on a substrate for subsequent reaction. In some embodiments, the alkyl halide comprises carbon and a halogen. In some embodiments, the halogen comprises bromine or iodine. In some embodiments, the halogen is insoluble in the metal film. In this context, the halogen that is insoluble in the metal film comprises about 2% or less, about 1% or less, or about 0.5% or less of the metal film on an atomic basis. In some embodiments, the alkyl halide has the general formula RX, where R is an alkyl, alkenyl, aryl, or other carbon group. In some embodiments, R comprises 1 to 2, 1 to 4, or 1 to 6 carbon atoms. In some embodiments, the alkyl halide comprises or consists essentially of iodoethane (H5C2I) or diiodomethane (CHI2). In this context, an alkyl halide consisting essentially of the recited species comprises greater than 95%, 98%, 99%, or 99.5% of the recited species on a molar basis, excluding any inert diluent gases.

[0083] The alkyl halide is delivered to the process chamber as an alkyl halide-containing gas. The alkyl halide-containing gas can be provided in one or more pulses or continuously. The flow rate of the alkyl halide-containing gas can be any suitable flow rate, including, but not limited to, a flow rate in the range of about 1 to about 5000 sccm, or in the range of about 2 to about 4000 sccm, or in the range of about 3 to about 3000 sccm, or in the range of about 5 to about 2000 sccm. The alkyl halide-containing gas can be provided at any suitable pressure, including, but not limited to, a pressure in the range of about 5 mTorr to about 25 Torr, or in the range of about 100 mTorr to about 20 Torr, or in the range of about 5 Torr to about 20 Torr, or in the range of about 50 mTorr to about 2000 mTorr, or in the range of about 100 mTorr to about 1000 mTorr, or in the range of about 200 mTorr to about 500 mTorr.

[0084] The period of time during which the substrate is exposed to the alkyl halide-containing gas can be any suitable amount of time necessary to allow the alkyl halide to form a sufficient adsorbed layer on the substrate surface. For example, the process gas can be flowed into the process chamber for a period of about 0.1 seconds to about 90 seconds. In some time-domain ALD processes, the alkyl halide-containing gas is exposed to the substrate surface for a period of about 0.1 seconds to about 90 seconds, or about 0.5 seconds to about 60 seconds, or about 1 second to about 30 seconds, or about 2 seconds to about 25 seconds, or about 3 seconds to about 20 seconds, or about 4 seconds to about 15 seconds, or about 5 seconds to about 10 seconds.

[0085] In some embodiments, an inert gas can be provided to the process chamber simultaneously with the alkyl halide-containing gas. The inert gas can be mixed with the alkyl halide-containing gas (e.g., as a diluent gas) or provided separately, and can be pulsed or provided as a constant flow. In some embodiments, the inert gas is flowed into the process chamber at a constant flow within a range of about 1 to about 10,000 sccm. The inert gas can be any inert gas, such as argon, helium, neon, or a combination thereof.

[0086] The temperature of the substrate during deposition can be controlled, for example, by setting the temperature of the substrate support or susceptor. In some embodiments, the substrate is maintained at a temperature in the range of about 0°C to about 600°C, or in the range of about 25°C to about 500°C, or in the range of about 50°C to about 450°C, or in the range of about 100°C to about 400°C, or in the range of about 200°C to about 400°C, or in the range of about 250°C to about 350°C. In some embodiments, the substrate is maintained at a temperature below the decomposition temperature of the metal precursor. In some embodiments, the substrate is maintained at a temperature below the decomposition temperature of the alkyl halide. In some embodiments, the substrate is maintained at a temperature between the decomposition temperature of the alkyl halide and the decomposition temperature of the metal precursor.

[0087] In one or more embodiments, the substrate is maintained at a temperature of about 400° C. or less, or about 350° C. or less, or less than about 300° C. In one or more embodiments, the substrate is maintained at a temperature of about 250° C. or more, or about 300° C. or more, or greater than about 350° C. In some embodiments, the substrate is maintained at a temperature of about 280° C.

[0088] In addition to the above, additional process parameters can be adjusted during exposure of the substrate to the alkyl halide-containing gas. For example, in some embodiments, the process chamber can be maintained at a pressure in the range of about 0.2 to about 100 Torr, or about 0.3 to about 90 Torr, or about 0.5 to about 80 Torr, or about 1 to about 50 Torr.

[0089] Next, at 708, the process chamber (particularly for time-domain ALD) can be purged using an inert gas (this is not required for spatial ALD processes in which a gas curtain separates the reactive gases). The inert gas can be any inert gas, such as argon, helium, neon, or the like. In some embodiments, the inert gas can be the same as the inert gas provided to the process chamber during exposure of the substrate to the alkyl halide-containing gas at 706, or alternatively, can be different. In embodiments in which the inert gas is the same, purging can be performed by diverting the first process gas from the process chamber and allowing the inert gas to flow through the process chamber to purge any excess first process gas components or reaction by-products from the process chamber. In some embodiments, the inert gas can be provided at the same flow rate as used in connection with the first process gas described above, or in some embodiments, the flow rate can be increased or decreased. For example, in some embodiments, the inert gas can be provided to the process chamber at a flow rate of about 0 to about 10,000 sccm to purge the process chamber. In spatial ALD, a purge gas curtain is maintained between the reactive gas flows, and purging of the process chamber is not required. In some embodiments of spatial ALD processes, the process chamber or a region of the process chamber can be purged with an inert gas.

[0090] The flow of inert gas can facilitate removing any excess first process gas components and / or excess reaction by-products from the process chamber to prevent undesired gas-phase reactions of the first and second process gases.

[0091] Next, at 710, the substrate is exposed to a second process gas for a second period of time. The second process gas includes a metal precursor that reacts with the adsorbed halogen layer on the substrate surface to deposit a metal film. The second reactive gas can also be referred to as a metal precursor gas.

[0092] The metal precursor can be any precursor suitable for reacting with an adsorbed halogen layer on a substrate. In some embodiments, the metal precursor comprises a metal center and one or more ligands. In some embodiments, the metal center comprises one or more metal atoms. In other words, in some embodiments, the metal precursor is one or more of a dimer, trimer, or tetramer.

[0093] The metal precursor can be any suitable precursor having a decomposition temperature above the deposition temperature. In some embodiments, the metal precursor is substantially free of oxygen or nitrogen atoms. Accordingly, in these embodiments, the metal precursor is free of carbonyl, oxo, amine, or imine ligands. Within these parameters, the number of ligands on the metal precursor and the type of ligand can vary based on, for example, the oxidation state of the metal atom. The metal precursor can be homoleptic or heteroleptic. In some embodiments, the metal precursor includes at least one ligand containing an optionally alkyl-substituted cyclopentadiene (Cp) ring. In some embodiments, the metal precursor includes at least one ligand containing an optionally alkyl-substituted benzene ring. In some embodiments, the metal precursor includes at least one p-cymene ligand. In some embodiments, the metal precursor includes at least one ligand containing a ring-opened or ring-closed diene. In some embodiments, the metal precursor includes at least one 1,3-butadiene ligand. In some embodiments, the metal precursor includes at least one 1,5-hexadiene ligand. In some embodiments, the metal precursor includes at least one aromatic ligand. In some embodiments, at least one aromatic ligand comprises a benzene ring. In some embodiments, the benzene ring comprises at least one organic substituent comprising between 1 and 6 carbon atoms. In some embodiments, the aromatic ligand comprises at least one ethylbenzene ligand. In some embodiments, the metal precursor comprises, or consists essentially of, bis(ethylbenzene)molybdenum. In some embodiments, the metal precursor comprises, or consists essentially of p-cymene ruthenium 1,5-hexadiene.

[0094] The metal of the metal precursor corresponds to the metal of the metal film to be deposited. In some embodiments, the metal is selected from molybdenum, ruthenium, cobalt, copper, platinum, nickel, or tungsten. In some embodiments, the oxidation state of the metal of the metal precursor is 0. In other words, in some embodiments, the metal precursor comprises a zero-valent metal complex.

[0095] Additional process parameters can be adjusted during exposure of the substrate to the metal precursor gas. For example, in some embodiments, the process chamber can be maintained at a pressure in the range of about 0.2 to about 100 Torr, or about 0.3 to about 90 Torr, or about 0.5 to about 80 Torr, or about 1 to about 50 Torr.

[0096] The metal precursor is delivered to the processing chamber as a metal precursor gas. The metal precursor gas can be provided in one or more pulses or continuously. The flow rate of the metal precursor gas can be any suitable flow rate, including, but not limited to, a flow rate in the range of about 1 to about 5,000 sccm, or in the range of about 2 to about 4,000 sccm, or in the range of about 3 to about 3,000 sccm, or in the range of about 5 to about 2,000 sccm. The metal precursor gas can be provided at any suitable pressure, including, but not limited to, a pressure in the range of about 5 mTorr to about 25 Torr, or in the range of about 100 mTorr to about 20 Torr, or in the range of about 5 Torr to about 20 Torr, or in the range of about 50 mTorr to about 2,000 mTorr, or in the range of about 100 mTorr to about 1,000 mTorr, or in the range of about 200 mTorr to about 500 mTorr.

[0097] The substrate is exposed to the metal precursor gas for any suitable amount of time necessary to allow the metal precursor to react with the adsorbed halogen on the substrate surface. For example, the process gas can be flowed into the process chamber for a period of about 0.1 seconds to about 90 seconds. In some time-domain ALD processes, the metal precursor gas is exposed to the substrate surface for a period of about 0.1 seconds to about 90 seconds, or about 0.5 seconds to about 60 seconds, or about 1 second to about 30 seconds, or about 2 seconds to about 25 seconds, or about 3 seconds to about 20 seconds, or about 4 seconds to about 15 seconds, or about 5 seconds to about 10 seconds.

[0098] In some embodiments, an inert gas can be provided to the process chamber simultaneously with the metal precursor gas. The inert gas can be mixed with the metal precursor gas (e.g., as a diluent gas) or provided separately, and can be pulsed or provided as a constant flow. In some embodiments, the inert gas is flowed into the processing chamber at a constant flow rate in the range of about 1 to about 10,000 sccm. The inert gas can be any inert gas, such as argon, helium, neon, or a combination thereof.

[0099] Next, at 712, the process chamber can be purged using an inert gas. The inert gas can be any inert gas, such as, for example, argon, helium, neon, etc. In some embodiments, the inert gas can be the same as the inert gas provided to the process chamber during the previous process routine, or alternatively, can be different. In embodiments where the inert gas is the same, purging can be performed by diverting the second process gas from the process chamber and allowing the inert gas to flow through the process chamber to purge any excess second process gas components or reaction by-products from the process chamber. In some embodiments, the inert gas can be provided at the same flow rate as used in connection with the second process gas described above, or in some embodiments, the flow rate can be increased or decreased. For example, in some embodiments, the inert gas can be provided to the process chamber at a flow rate of 0 to greater than about 10,000 sccm to purge the process chamber.

[0100] While the generic embodiment of the processing method shown in FIG. 7 includes only two pulses of reactive gas, it will be understood that this is merely exemplary and that additional pulses of reactive gas can be used. In some embodiments, the method is performed without using an oxygen-containing reactive gas. The subprocess of 704 includes cycles. The cycles can be performed in any order as long as the reactive gases are separated by purging the processing chamber. In some embodiments, the metal film is deposited at a rate of about 0.2 Å / cycle or greater, about 0.3 Å / cycle or greater, about 0.4 Å / cycle or greater, about 0.5 Å / cycle or greater, about 0.6 Å / cycle or greater, about 0.7 Å / cycle or greater, about 0.8 Å / cycle or greater, about 0.9 Å / cycle or greater, about 1.0 Å / cycle or greater, or about 1.2 Å / cycle or greater.

[0101] The deposition process is carried out as a thermal process without the use of plasma reactants, in other words, in some embodiments the method is carried out without a plasma.

[0102] Next, at 714, it is determined whether the metal film has achieved the predetermined thickness. If the predetermined thickness has not been achieved, method 700 returns to 704 to continue forming metal films until the predetermined thickness is reached. After the predetermined thickness is reached, method 700 may end or may proceed to 716 for optional further processing (e.g., bulk deposition of another metal film). In some embodiments, the metal film may be deposited to form a total layer thickness of about 10 Å to about 10,000 Å, or in some embodiments, about 10 Å to about 1000 Å, or in some embodiments, about 50 Å to about 5,000 Å.

[0103] In some embodiments, the metal layer comprises about 75 atomic % or more molybdenum, or about 80 atomic % or more molybdenum, or about 85 atomic % or more molybdenum, or about 90 atomic % or more molybdenum, or about 95 atomic % or more molybdenum.

[0104] In some embodiments, the metal layer contains less than or equal to about 10 atomic % oxygen, or less than or equal to about 9 atomic % oxygen, or less than or equal to about 8 atomic % oxygen, or less than or equal to about 7 atomic % oxygen, or less than or equal to about 6 atomic % oxygen, or less than or equal to about 5 atomic % oxygen, or less than or equal to about 4 atomic % oxygen, or less than or equal to about 3 atomic % oxygen.

[0105] In some embodiments, the metal layer comprises in the range of about 0.02 to about 5 atomic percent iodine, or up to about 1 atomic percent iodine.

[0106] In some embodiments, the metal layer comprises no more than about 20 atomic % carbon, or no more than about 15 atomic % carbon, or no more than about 10 atomic % carbon, or no more than about 5 atomic % carbon.

[0107] In some embodiments, the metal layer comprises about 90 atomic % or more molybdenum, about 3 atomic % or less oxygen, about 1 atomic % or less iodine, and about 10 atomic % or less carbon.

[0108] In some embodiments, the metal layer has a resistivity of about 40 μΩ·cm or less, or about 35 μΩ·cm or less, or about 30 μΩ·cm or less, or about 25 μΩ·cm or less, or about 20 μΩ·cm or less. In some embodiments, the metal layer comprises molybdenum and has a resistivity of about 40 μΩ·cm or less, or about 35 μΩ·cm or less, or about 30 μΩ·cm or less, or about 25 μΩ·cm or less, or about 20 μΩ·cm or less.

[0109] In some embodiments, the metal film is further processed by annealing the metal film. Without being bound by theory, it is believed that annealing the film at high temperatures in an Ar or H ambient reduces carbon and halogen impurities in the metal film. In some embodiments, the metal film is annealed in an ambient containing argon or hydrogen gas (H) to reduce the atomic concentration of carbon and / or halogen impurities.

[0110] Metal films deposited by some embodiments are smoother than films deposited by known oxygen-based deposition processes, and in some embodiments, the metal films have a surface roughness of about 10% or less, about 8% or less, about 5% or less, or about 2% or less of the thickness of the metal film.

[0111] The metal film has a high purity. In some embodiments, the metal film has a carbon content of about 2% or less, about 1% or less, or about 0.5% or less on a carbon atom basis. In some embodiments, the metal film has a halogen content of about 1% or less or about 0.5% or less on a halogen atom basis. In some embodiments, the metal film has a purity of about 95% or more, about 97% or more, about 99% or more, about 99.5% or more, or about 99.9% or more metal atoms on an atomic basis.

[0112] Some embodiments of the present disclosure selectively deposit a first metal film on a second metal surface over a first dielectric surface. These methods are similar to method 700 described above, except that a substrate is provided that includes a first dielectric surface and a second metal surface. The first metal (metal film) and the second metal (substrate surface) can be the same metal or different metals. In some embodiments, the first metal is molybdenum, ruthenium, cobalt, copper, platinum, nickel, or tungsten, and the second metal is tungsten, cobalt, or copper.

[0113] The first dielectric surface can be formed from any suitable dielectric material. In some embodiments, the dielectric material contains nitrogen or oxygen atoms. Without being bound by theory, it is believed that these materials react with alkyl halides, preventing the halogens from adsorbing onto the substrate surface and catalyzing the reaction with the metal precursor. Accordingly, little, if any, metal film forms on the dielectric surface.

[0114] In some embodiments, the deposition temperature is below the decomposition temperature of the alkyl halide. Again, without being bound by theory, it is believed that when the alkyl halide decomposes, the halogen becomes available for reaction with the metal precursor on all surfaces (regardless of composition), resulting in metal film deposition on all substrate surfaces, including dielectric surfaces. In some embodiments, the deposition temperature is at or above the decomposition temperature of the alkyl halide.

[0115] Some embodiments of the present disclosure selectively deposit a first metal film on a first dielectric surface over a second metal surface. These methods are similar to method 700 described above, except that a substrate is provided that includes a first dielectric surface and a second metal surface, and the substrate is exposed to a blocking compound at 703.

[0116] At 703, a substrate including at least a second metal surface and a first dielectric surface is exposed to a blocking compound. The blocking compound can be any suitable compound for blocking deposition on the second metal surface. In some embodiments, the blocking compound includes at least one triple bond between two carbon atoms. In other words, in some embodiments, the blocking compound includes an alkyne. In some embodiments, the blocking compound has a general formula of R'≡R"; in some embodiments, R' and R" are the same. In some embodiments, R' and / or R" are alkyl or other carbon groups. In some embodiments, the blocking compound includes 4-12 carbon atoms. In some embodiments, R' and / or R" are linear. In some embodiments, R' and / or R" are branched. In some embodiments, the blocking compound includes 3-hexyne.

[0117] The first metal (metal film) and the second metal (substrate surface) can be the same metal or different metals. In some embodiments, the first metal is molybdenum, ruthenium, cobalt, copper, platinum, nickel, or tungsten, and the second metal is tungsten, cobalt, or copper.

[0118] The first dielectric surface can be formed from any suitable dielectric material. In some embodiments, the dielectric material includes nitrogen or oxygen atoms.

[0119] As previously mentioned, in some embodiments, the deposition temperature is at or above the decomposition temperature of the alkyl halide. In some embodiments, the deposition temperature is about 250°C or higher, about 260°C or higher, about 270°C or higher, about 280°C or higher, about 290°C or higher, or about 300°C or higher. In some embodiments, the deposition temperature is in the range of about 250°C to about 450°C, or in the range of about 300°C to about 400°C. In some embodiments, the deposition temperature is about 350°C.

[0120] As previously mentioned, without being bound by theory, it is believed that these materials react with the alkyl halides, preventing the halogens from adsorbing onto the substrate surface and catalyzing the reaction with the metal precursor. Accordingly, little, if any, metal film forms on the dielectric surface.

[0121] However, when the deposition temperature exceeds the decomposition temperature of the alkyl halide, halogen atoms deposit over the entire substrate surface, thereby enabling deposition on the dielectric surface. In some embodiments, the metal surface is blocked by a blocking compound, allowing little, if any, metal film to form on the metal surface. Accordingly, deposition of the metal film is selective to the dielectric surface over the metal surface.

[0122] In general, the deposition of highly pure metal films can be understood as follows: A substrate maintained at the deposition temperature is exposed to an alkyl halide (RX), adsorbing R and X onto the substrate, where R is a carbon group and X is a halogen. R is desorbed in the form of RR or R-, and X remains adsorbed on the substrate. The substrate is exposed to a metal precursor ML, where M is the metal and L is a ligand. ML reacts with the adsorbed X to form MX on the substrate surface and liberates L. MX reacts with other MX moieties on the substrate to form MM. This reaction can yield XX or X-. XX can be desorbed and purged. X- can remain on the surface and further react with ML.

[0123] According to the inventors, this general mechanism relies on several assumptions. First, X is insoluble in M. Without being bound by theory, the insolubility of X indicates that X will not be found in significant amounts in the final metal film. While it is possible to ignore this assumption (e.g., by utilizing a halogen soluble in M), it is believed that using a halogen soluble in M ​​(X) would result in a lower purity metal film. Second, in terms of bond strength, ML is weaker than MX, which is weaker than MM. Again, without being bound by theory, these thermodynamic relationships ensure that the above-mentioned reaction is thermodynamically favorable. Finally, ML is thermally stable at the deposition temperature. In other words, the thermal decomposition temperature of the metal precursor is higher than the deposition temperature. This theory suggests that when the metal precursor decomposes, the deposited film will contain a significant amount of precursor ligand L, which is typically considered a carbon impurity.

[0124] The present inventors have surprisingly found that a process comprising metal precursors, alkyl halides, and process conditions that meet all of the above requirements deposits highly pure metal films.

[0125] In addition, the inventors have surprisingly found that when the deposition temperature is below the thermal decomposition temperature of the alkyl halide, the deposition process becomes selective to metal surfaces over dielectric surfaces without the need for the use of a blocking layer.

[0126] Furthermore, the present inventors have surprisingly found that the deposition process can be made selective by exposing the metal surface to small amounts of an alkyne blocking compound when the deposition temperature is at or above the thermal decomposition temperature of the alkyl halide.

[0127] Some embodiments of the present disclosure advantageously provide methods for depositing conformal metal films on substrates having high aspect ratio structures. In this context, the term "conformal" means that the thickness of the metal film is uniform across the substrate surface. As used herein and in the appended claims, the term "substantially conformal" means that the thickness of the metal film does not vary by more than about 10%, 5%, 2%, 1%, or 0.5% relative to the average thickness of the film. In other words, a substantially conformal film has a conformality of greater than about 90%, 95%, 98%, 99%, or 99.5%.

[0128] One or more embodiments of the present disclosure are directed to a memory device including a molybdenum conductive layer. In some embodiments, the molybdenum conductive layer comprises at least about 90 atomic % molybdenum, at most about 3 atomic % oxygen, at most about 1 atomic % iodine, and at most about 10 atomic % carbon, and a resistivity of at most about 40 μΩ cm.

[0129] In some embodiments, the molybdenum conductive layer is formed on a barrier layer. In some embodiments, the barrier layer has a thickness of about 10 Å, 20 Å, 30 Å, 40 Å, or 50 Å or less. In some embodiments, the molybdenum conductive layer is formed on a substrate without an intervening barrier layer.

[0130] The above disclosure relates to the deposition of metal films by sequential pulsing of reactants. The following disclosure relates to the deposition of metal films by simultaneous or constant flow processes. In some embodiments, the sequential pulsing method is an ALD method. In some embodiments, the simultaneous or constant flow method is a CVD method. While the process steps are different, many of the reactants and process parameters are similar.

[0131] Figure 8 illustrates a generalized method 800 for forming a metal film on a substrate according to one or more embodiments of the present disclosure. Figure 9 illustrates an exemplary substrate for processing according to one or more embodiments of the present disclosure. Method 800 generally begins at 810, where a substrate 900 on which a metal film is to be formed is provided and placed into a processing chamber.

[0132] Referring to FIG. 9 , an exemplary substrate 900 is shown. In some embodiments, the substrate 900 has a substrate surface 905 that includes at least one feature 910. The feature 910 has sidewalls 912, 914 and a bottom 916. In some embodiments, a dielectric material 920 forms the sidewalls 912, 914, and a metallic material 930 forms the bottom 916. While the illustrated embodiment refers to two sidewalls, such as a trench-like structure, those skilled in the art will recognize that the present disclosure is not limited to trenches. In some embodiments, the feature constitutes a round via; such a via technically has a single round sidewall, but would appear in cross section as two sidewalls, as shown.

[0133] In some embodiments, the substrate 900 may undergo one or more optional pre-processing steps. At 815, the substrate may optionally have one or more layers formed on the substrate surface.

[0134] In some embodiments, a metal nitride liner is deposited in the feature 910. In some embodiments, the metal nitride liner comprises titanium nitride. In some embodiments, the metal nitride liner has a thickness in a range from about 15 Å to about 40 Å. In some embodiments, the metal nitride liner has a thickness of about 20 Å or about 30 Å. In some embodiments, no liner is formed in the feature prior to the formation of the metal film. In some embodiments, no liner is present between the metal film and the bottom of the feature.

[0135] In some embodiments, a seed layer is deposited on the substrate surface. In some embodiments, the seed layer is a conformal layer. In some embodiments, the seed layer is continuous. In some embodiments, the seed layer has a thickness in the range of about 1 nm to about 5 nm, or in the range of about 1 nm to about 4 nm. In some embodiments, the seed layer comprises a ruthenium layer deposited by known atomic layer deposition methods. In some embodiments, the seed layer is deposited by ALD cycles including a ruthenium precursor exposure and an alkyl halide exposure with an intervening purge. In some embodiments, the seed layer is deposited by ALD cycles including a ruthenium precursor exposure and an ammonia plasma exposure with an intervening purge.

[0136] In some embodiments, the bottom 916 comprises a metal and the optional pretreatment comprises a cleaning process. In some embodiments, the metal bottom 916 of the feature is cleaned to remove oxides from the metal prior to formation of the metal film within the feature.

[0137] Optionally, the substrate is exposed to a blocking compound at 820. This process step is described in more detail below and can be useful for controlling the selectivity of the deposition process on substrates that include both metal and dielectric surfaces.

[0138] At 830, a metal film is formed on the substrate. In some embodiments, the metal film is formed by exposing the substrate to a metal precursor and an alkyl halide catalyst while the substrate is maintained at a deposition temperature. In some embodiments, the alkyl halide catalyst and metal precursor are simultaneously exposed to the substrate. In some embodiments, the metal precursor and alkyl halide catalyst are separately and sequentially exposed to the substrate. In embodiments involving separate exposures, each "cycle" is a single exposure to the alkyl halide catalyst and metal precursor, in either order. The process of forming the metal film at 830 can begin by immersing the substrate in a catalytic gas. The catalytic gas includes an alkyl halide and is exposed to the substrate for a first period of time, as shown at 840. In some embodiments, the catalytic gas includes an alkyl halide catalyst that forms a catalytic layer on the metal bottom of the feature.

[0139] The alkyl halide can be any reactant suitable for adsorbing a layer onto a substrate for subsequent reaction. In other words, immersing the substrate in the alkyl halide forms an activated substrate surface. Alkyl halides are described above and elsewhere herein.

[0140] The alkyl halide can be provided to the process chamber in one or more pulses or continuously. In some embodiments, the alkyl halide includes an inert carrier gas and is referred to as an alkyl halide-containing gas. The flow rate and pressure of the alkyl halide or alkyl halide-containing gas can be any suitable value. The exemplary flow rates and pressures disclosed elsewhere herein for the alkyl halide-containing gas are also applicable to this embodiment.

[0141] The period of time for which the substrate is immersed in the alkyl halide can be any suitable amount of time necessary to allow the alkyl halide to form a sufficient adsorption layer on the substrate surface. For example, the alkyl halide can be allowed to immerse the substrate for a period of greater than about 3 seconds or greater than about 5 seconds. In some embodiments, the immersion period is within the range of about 3 seconds to about 60 seconds.

[0142] In some embodiments, an inert gas can be provided to the process chamber simultaneously with the alkyl halide-containing gas. The inert gas can be mixed with the alkyl halide (e.g., as a diluent gas) or provided separately, and can be pulsed or provided as a constant flow. The inert gas can be any inert gas, such as argon, helium, neon, or a combination thereof.

[0143] The substrate is then exposed to a second process gas for a second period of time at 850. The second process gas includes a metal precursor that reacts with the adsorbed alkyl halide or halogen layer on the substrate surface to deposit a metal film. The second reactive gas may also be referred to as a metal precursor gas.

[0144] The metal precursor can be any precursor suitable for reacting with an adsorbed alkyl halide or halogen layer on a substrate. Suitable metal precursors are described elsewhere herein.

[0145] The metal precursor is delivered to the processing chamber as a metal precursor gas. The metal precursor gas can be provided in one or more pulses or continuously. The flow rate and pressure of the metal precursor gas can be any suitable flow rate and pressure. Exemplary values ​​for flow rate and pressure are discussed elsewhere herein.

[0146] The substrate is exposed to the metal precursor gas for any suitable amount of time necessary to allow the metal precursor to react with the adsorbed halogen on the substrate surface. For example, the process gas can be flowed into the process chamber for a period of about 60 seconds or more. In some embodiments, the exposure period to the metal precursor is about 100 seconds, about 200 seconds, about 300 seconds, about 400 seconds, or about 500 seconds.

[0147] The temperature of the substrate during exposure to the metal precursor can be controlled, for example, by setting the temperature of the substrate support or susceptor. This temperature is also referred to as the deposition temperature. In some embodiments, the substrate is maintained at a temperature below the decomposition temperature of the metal precursor. In some embodiments, the substrate is maintained at a temperature below the decomposition temperature of the alkyl halide. In some embodiments, the substrate is maintained at a temperature between the decomposition temperature of the alkyl halide and the decomposition temperature of the metal precursor.

[0148] In one or more embodiments, the substrate is maintained at a temperature of about 400° C. or less, or about 350° C. or less, or about 300° C. or less, or about 250° C. or less, or about 200° C. or less. In one or more embodiments, the substrate is maintained at a temperature of about 150° C. or more, or about 200° C. or more, or about 250° C. or more, or about 300° C. or more, or about 350° C. or more. In some embodiments, the substrate is maintained at a temperature of about 225° C. or about 280° C.

[0149] The deposition process is carried out as a thermal process without the use of plasma reactants, in other words, the method is carried out without a plasma.

[0150] Next, at 860, it is determined whether the metal film has achieved the predetermined thickness. If the predetermined thickness has not been achieved, method 800 returns to 850 to continue exposing the substrate to the metal precursor until the predetermined thickness is reached. After the predetermined thickness is reached, method 800 may end or may proceed to 870 for any further processing. In some embodiments, the metal film may be deposited to form a total layer thickness of from about 10 Å to about 10,000 Å, or in some embodiments, from about 20 Å to about 1000 Å, or in some embodiments, from about 50 Å to about 200 Å.

[0151] Some embodiments of the present disclosure selectively deposit a metal film on a metal surface over a first dielectric surface. These methods are similar to method 800 described above. A substrate is provided that includes a dielectric surface and a metal surface. In some embodiments, the substrate shown in FIG. 9 is processed to selectively form a bottom-up gap fill on the metal surface at the bottom 916 of a feature 910.

[0152] The metal of the metal film and the metal of the substrate surface can be the same metal or different metals. The dielectric surface can be formed from any suitable dielectric material. In some embodiments, the dielectric material contains nitrogen or oxygen atoms. Without being bound by theory, it is believed that these materials react with alkyl halides, preventing the halogens from adsorbing onto the substrate surface and catalyzing the reaction with the metal precursor. Accordingly, little, if any, metal film forms on the dielectric surface.

[0153] In some embodiments, the deposition temperature is below the decomposition temperature of the alkyl halide. Again, without being bound by theory, it is believed that when the alkyl halide decomposes, the halogen becomes available for reaction with the metal precursor on all surfaces (regardless of composition), resulting in metal film deposition on all substrate surfaces, including dielectric surfaces. In some embodiments, the deposition temperature is at or above the decomposition temperature of the alkyl halide.

[0154] Some embodiments of the present disclosure advantageously provide a method for controlling deposition of metal films. In some embodiments, the deposition rate is controlled. In some embodiments, the deposition location is controlled.

[0155] In various embodiment methods, atomic layer deposition (ALD) or chemical vapor deposition (CVD) methods are used to form the metal film. The above disclosure describes an exemplary ALD process with respect to FIG. 7 and an exemplary CVD process with respect to FIG. 8.

[0156] As previously mentioned, the generalized deposition process shown in Figures 7 and 8 is carried out as a thermal process without the use of plasma reactants. The use and effects of plasma and other additional reactants are discussed further below.

[0157] Some embodiments of the present disclosure advantageously provide methods for depositing metal films within substrate features or other structures. Exemplary features or structures include, but are not limited to, trenches and vias.

[0158] Some embodiments of the present disclosure advantageously provide deposition control methods for reducing film deposition outside of target features and near the feature opening. Without being bound by theory, it is believed that reducing deposition in these areas allows for faster gap filling within the target feature and reduces clogging near the feature opening and the formation of voids or seams within the feature.

[0159] 7 and 8, without limiting the scope of the disclosure, both the ALD and CVD processes described above utilize alkyl halides and metal precursors to deposit metal films. Without being bound by theory, it is believed that the alkyl halide functions as a catalyst in the deposition of the metal film. Accordingly, as particularly evidenced by the CVD process, a single exposure of a substrate surface to an alkyl halide can be used to deposit metal films with thicknesses greater than 10 nm.

[0160] Advantageously, some embodiments of the present disclosure provide a deposition control method for reducing catalytic activity in a predetermined area of ​​a substrate surface. In some embodiments, catalytic activity is reduced. In some embodiments, catalytic activity is eliminated.

[0161] 10A-10D, an exemplary substrate 400 is shown during processing according to one or more embodiments of the present disclosure. The substrate 1000 shown in FIGS. 10A-10D is simplified for illustrative purposes. As discussed above and shown in FIG. 9, in some embodiments, substrates of the present disclosure include features or structures not shown in FIGS. 10A-10D.

[0162] In Figure 10A, substrate 1000 includes substrate surface 1010. In Figure 4B, substrate surface 1010 is exposed to an alkyl halide to form activated surface 1020. As described above, alkyl halide 1040 adsorbs onto substrate surface 1010 to form activated substrate surface 1020.

[0163] In Figure 10C, a predetermined area of ​​activated surface 1020 is exposed to a passivation treatment to form passivated surface 1030. Although alkyl halides 1040 shown in Figures 10B and 10C are depicted as circular or oval, no particular molecular shape is intended to be conveyed. Similarly, the difference between the circular shape shown in Figures 10B and 10C and the oval shape shown in Figure 10C is only meant to convey the activity and / or relative concentration of alkyl halides on the substrate surface.

[0164] In Figure 10D, the substrate 1000 is exposed to a metal precursor to form a metal film 1050. As shown in Figure 10D, the thickness T1 of the metal film 1050 on the activated surface 1020 is greater than the thickness T2 of the metal film 1050 on the passivated surface 1030.

[0165] In some embodiments, the passivation treatment reduces the concentration of alkyl halides on the activated surface 1020. In some embodiments, the passivation treatment reduces the catalytic activity of alkyl halides on the activated surface 1020.

[0166] In some embodiments, the methods described above with respect to FIGS. 10A-10D are modified to include a passivation treatment prior to exposure to the alkyl halide. In this regard, the passivation treatment is understood to "superactivate" predetermined areas of the substrate surface 1010 prior to exposure to the alkyl halide. Upon exposure to the alkyl halide, the "superactivated" surfaces form alkyl halides at a higher concentration or activity than surfaces not exposed to the passivation treatment. The difference in concentration and / or activity between these surfaces can be used to control deposition. In some embodiments, these surfaces can be further passivated as described above with respect to FIGS. 10C-10D.

[0167] Thickness T1 is greater than thickness T2. Accordingly, some embodiments of the present disclosure advantageously provide a deposition control method for controlling the amount of deposition in a predetermined area of ​​a substrate surface.

[0168] In some embodiments, the ratio of T1:T2 is about 1:1 or greater, about 2:1 or greater, about 3:1 or greater, about 4:1 or greater, about 5:1 or greater, or about 10:1 or greater. In some embodiments, little or no metal deposition occurs on the passivated surface 1030. In other words, in some embodiments, thickness T2 is about 0. In other words, essentially no metal film 1050 is deposited on the passivated surface 1030. In this context, "essentially no" means that the metal film on the passivated surface covers less than 5%, less than 2%, less than 1%, or less than 0.5% of the passivated surface.

[0169] The thickness of the metal film 1050 deposited on the activated surface 1020 and the passivated surface 1030 is directly proportional to the deposition rate on the activated surface 1020 and the passivated surface 1030. Accordingly, some embodiments of the present disclosure advantageously provide a deposition control method for controlling the deposition rate in a predetermined area of ​​the substrate surface.

[0170] In some embodiments, the entire substrate surface is exposed to the passivation treatment. Some embodiments of the present disclosure can be used to control the amount of deposition across the entire substrate. Some embodiments of the present disclosure can be used to control the deposition rate across the entire substrate.

[0171] In some embodiments, although not shown, the substrate 1000 includes one or more features. In some embodiments, the passivated surface 1030 is an outer surface of one or more features. In some embodiments, the passivated surface 1030 is a surface near the top of a sidewall of one or more features.

[0172] Without being bound by theory, it is believed that surfaces near substrate features and the top surfaces of the sidewalls of those features are more highly activated (exhibit greater deposition) due to their close proximity to multiple exposed surfaces. The greater the deposition on these surfaces, the greater the likelihood that the feature will close before a sufficient amount of film has formed inside the feature. When a feature closes, seams or voids often form. Accordingly, in some embodiments, the passivated surface 1030 is a surface near the top of one or more features. Further, in some embodiments, the passivated surface 1030 is a surface near a substrate feature. In some embodiments, the metal film is deposited in a feature with reduced seams or voids. In some embodiments, the metal film is deposited in a feature that is substantially seam- or void-free. In this context, the term "substantially seamless" means that any gaps formed between sidewalls in the film are less than about 1% of the cross-sectional area of ​​the sidewalls.

[0173] In some embodiments, the predetermined areas of the substrate are exposed to hydrogen gas without the use of a plasma.

[0174] In some embodiments, a pulse of hydrogen gas is introduced into the ALD deposition cycle described above. In other words, the substrate can be exposed to a pulse sequence of alkyl halide, purge, hydrogen gas, purge, metal precursor, and purge. In some embodiments, the substrate is exposed to an additional pulse of hydrogen gas, followed by a purge after exposure to the metal precursor. In some embodiments, the substrate is exposed to an additional pulse of hydrogen gas, followed by a purge after exposure to the alkyl halide. In some embodiments, the purge step between each exposure to the metal precursor and / or alkyl halide is performed in some, but not all, cycles.

[0175] In some embodiments, hydrogen gas exposure is incorporated into the CVD deposition cycle described above. In other words, the substrate can be immersed in an alkyl halide, exposed to hydrogen gas, and exposed to a metal precursor. In some embodiments, the substrate is exposed to hydrogen gas before exposure to the metal precursor. In some embodiments, hydrogen gas and the metal precursor are flowed simultaneously.

[0176] In some embodiments, predetermined areas of the substrate are exposed to a plasma containing one or more of hydrogen (H), ammonia (NH), or argon (Ar). In some embodiments, the plasma used to passivate the surface is a low-power plasma. In some embodiments, the plasma has a power in the range of about 50 W to about 500 W, in the range of about 50 W to about 300 W, in the range of about 50 W to about 200 W, or in the range of about 50 W to about 100 W.

[0177] In some embodiments, the plasma exposure time is about 30 seconds or less, about 20 seconds or less, about 15 seconds or less, about 10 seconds or less, about 5 seconds or less, or about 2 seconds or less.

[0178] In some embodiments, the plasma is a conductively coupled plasma (CCP). In some embodiments, the plasma is an inductively coupled plasma (ICP). In some embodiments, the plasma is a direct plasma generated within the processing environment. In some embodiments, the plasma is a remote plasma generated outside the processing environment.

[0179] In some embodiments, a plasma pulse is introduced into the ALD deposition cycle described above. In some embodiments, the plasma pulse replaces the hydrogen gas pulse described above with respect to the ALD deposition cycle.

[0180] In some embodiments, a plasma pulse is introduced into the CVD deposition cycle described above. In some embodiments, the plasma pulse replaces the hydrogen gas exposure described above with respect to the CVD deposition cycle.

[0181] 11 illustrates a process for seamless gap filling according to one or more embodiments of the present disclosure. The substrate 1100 shown has at least one feature 1105, which has a first metal 1110 at a bottom 1106 of the feature 1105 and at least one dielectric sidewall 1120. The first metal 1110 has a first metal surface 1111 exposed within the feature 1105. The dielectric sidewall 1120 has a top surface 1121 outside the feature 1105 and one or more sidewall surfaces 1122 within the feature 1105.

[0182] In some embodiments, the substrate 1100 is exposed to an optional cleaning process. The cleaning process cleans the first metal surface 1111 on the bottom 1106 of the feature 1105. In some embodiments, the cleaning process removes oxide from the first metal surface 1111. The cleaning process in some embodiments includes degassing the substrate with or without hydrogen, argon sputtering with or without hydrogen, water vapor cleaning, or APC cleaning.

[0183] In some embodiments, a catalyst-enhanced chemical vapor deposition (CECVD) process is used to deposit the metal film 1130. The metal film 1130 (e.g., a ruthenium film) is selectively deposited on the first metal 1110 to cover the first metal surface 1111. The metal film 1130 is deposited to a thickness that partially fills the feature 1105, such that the top surface of the metal film 1131 is below the top surface 1121 of the dielectric 1120.

[0184] Optionally, a blocking layer 1140 is formed on the top surface 1131 of the metal film 1130. The blocking layer 1140 can be any suitable material known to those skilled in the art to be capable of preventing the deposition of a liner material on the top surface 1131 of the metal film 1130. In some embodiments, the blocking layer 1140 comprises a self-assembled monolayer (SAM).

[0185] In some embodiments, a conformal liner 1150 is formed on the dielectric sidewalls 1122 and top surface 1121 of the dielectric 1120. In some embodiments, substantially no conformal liner 1150 is formed on the top surface 1131 of the metal film 1130 or on any blocking layer 1140. When used in this manner, the term "substantially no" means that no more than about 10%, 5%, 2%, or 1% of the surface area of ​​the metal film 1130 or any blocking layer 1140 has liner material deposited on it. This does not include the edges of the sidewalls where the sidewalls meet the top surface of the metal film or any blocking layer. In some embodiments, a conformal liner 1150 has a thickness of about 30 Å, 25 Å, or 20 Å or less. In some embodiments, the conformal liner 1150 has a thickness sufficient to form a continuous film. In some embodiments, the conformal liner 1150 includes titanium nitride (TiN) and / or tantalum nitride (TaN).

[0186] In some embodiments, the blocking layer 1140 is optionally removed from the top surface 1131 of the metal film 1130. The blocking layer 1140 can be removed by any suitable technique known to those skilled in the art.

[0187] In some embodiments, the feature 1105 is filled with a metal film 1130 to form an overburden 1133 covering the dielectric sidewalls and a conformal liner 1150 on the top surface of the dielectric.

[0188] In some embodiments, metal film 1130 is optionally annealed to change some properties of the film to form annealed metal film 1160. For example, in some embodiments, metal film 1130 is annealed to increase the density of the film. Annealing can be performed under any suitable conditions and by any suitable technique known to those skilled in the art.

[0189] In some embodiments, a portion of the annealed metal film 1160 (or metal film 1130, if not annealed) is removed by any suitable technique. In some embodiments, a portion of the annealed metal film 1160 (or metal film 1130) and at least a portion of the conformal liner 1150 are removed to expose the top surface 1121 of the dielectric 1120. In some embodiments, a portion of the annealed metal film 1160 (or metal film 1130) and a portion of the dielectric 1120, and at least a portion of the conformal liner 1150 are removed. In some embodiments, all of the conformal liner 1150 is removed. In some embodiments, the annealed metal film 1160 (or metal film 1130), the conformal liner 1150, and a portion of the dielectric 1120 are removed by chemical mechanical planarization.

[0190] In some embodiments, one or more of the blocking layer 1140 or the conformal liner 1150 are deposited prior to the formation of the metal film 1130, such that the blocking layer 1140 is formed directly on the first metal 1110. In some embodiments, the blocking layer 1140 is removed from the surface of the first metal 1110 prior to depositing the metal film 1130. In some such embodiments, the deposition of the metal film 1130 proceeds first by an ALD process and then by a CECVD process to grow the metal film.

[0191] In some embodiments, a combination of atomic layer deposition and catalyst-enhanced chemical vapor deposition is used. The ALD portion of some embodiments follows a sequence of a metal precursor (e.g., a ruthenium precursor) soak, a purge, a catalyst precursor (e.g., an iodine precursor) soak, and a purge. Individual exposures during the ALD portion in some embodiments have short durations. In some embodiments, the soak portion is performed for less than 10 seconds, 5 seconds, 4 seconds, 3 seconds, or 2 seconds. In some embodiments, the metal precursor soak is longer than the catalyst precursor soak. In some embodiments, the purge portion is performed for less than 5 seconds, 4 seconds, 3 seconds, 2 seconds, or 1 second. The CECVD portion of the process, whether coupled to the ALD section or not, typically has a longer pulse time and a different pulse sequence. In some embodiments, the CECVD sequence includes a catalyst precursor soak, followed by a metal precursor soak, and then a purge. The catalyst precursor soak in some CECVD embodiments has a duration in the range of 5 to 300 seconds, 10 to 240 seconds, 15 to 210 seconds, 20 to 180 seconds, 25 to 120 seconds, or 30 to 60 seconds. In some embodiments, the metal precursor soak in some CECVD embodiments has a duration in the range of 20 to 1200 seconds, 30 to 800 seconds, 40 to 600 seconds, 50 to 450 seconds, or 60 to 300 seconds. In some embodiments, the catalyst soak has a shorter duration than the metal soak. In some embodiments, the purge has a duration in the range of 1 to 100 seconds, 2 to 80 seconds, 3 to 60 seconds, 4 to 30 seconds, or 5 to 10 seconds.

[0192] In some embodiments, the process includes an initial ALD-type process to build up the thickness of the second metal. After a predetermined thickness of the second metal is formed, a CECVD process is repeatedly performed to grow a film having a predetermined thickness. In some embodiments, the CECVD process is ineffective for growing the second metal without the initial metal layer deposited by the selective ALD process. The ALD-type sequence of some embodiments deposits the second metal at a faster rate than the CECVD process. In some embodiments, after forming the metal film 1130 to a predetermined thickness (e.g., at the top of a feature), the process sequence switches to an ALD-type sequence. The metal film can then be further processed as described herein.

[0193] Throughout this specification, reference to "one embodiment," "a particular embodiment," "one or more embodiments," or "an embodiment" means that a particular feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of the present disclosure. Thus, the appearances of phrases such as "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. Furthermore, particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0194] Although the disclosure herein has been described with reference to particular embodiments, it is to 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 in the disclosed method and apparatus without departing from the spirit and scope of the disclosure. Therefore, it is intended that the disclosure cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. 1. A method of forming a seamless gap fill, comprising sequentially exposing a substrate having at least one feature including a bottom and a sidewall to a metal precursor and an alkyl halide catalyst, and maintaining the substrate at a deposition temperature to form a second metal film on the bottom of the at least one feature, wherein the bottom of the at least one feature comprises a first metal and the sidewall of the at least one feature comprises a dielectric, the metal precursor has a decomposition temperature above the deposition temperature, the alkyl halide comprises carbon and a halogen, and the halogen comprises bromine or iodine; selectively forming a blocking film on the top surface of the second metal film; forming a liner on the sidewalls and a top surface of the sidewalls, the liner not being formed substantially on the top surface of the second metal film; removing the blocking layer from the top surface of the second metal film; filling the at least one feature with the second metal film to cover the sidewalls and the liner on the top surface of the sidewalls; removing a portion of the second metal film and the dielectric, and at least a portion of the liner to form a seamless gap fill; A method comprising:

2. The method of claim 1 , wherein the first metal at the bottom of the feature comprises one or more of molybdenum, ruthenium, cobalt, copper, platinum, nickel, or tungsten.

3. The method of claim 1 , wherein the metal film comprises one or more of tungsten, ruthenium, molybdenum, or copper.

4. 10. The method of claim 1, wherein the metal precursor comprises a metal atom bonded to one or more of an alkyl-substituted benzene ring and a ring-opened or ring-closed diene.

5. 10. The method of claim 1, wherein the alkyl halide comprises iodoethane or diiodomethane.

6. The method of claim 1 , wherein the metal film is selectively formed on the bottom of the feature relative to the sidewalls.

7. The method of claim 1 , wherein the metal precursor and the alkyl halide catalyst are exposed to the substrate separately and sequentially within a cycle.

8. 8. The method of claim 7, wherein the alkyl halide catalyst is exposed to the substrate prior to the exposure of the metal precursor to form a catalyst layer on the metal bottom of the feature.

9. 9. The method of claim 8, further comprising exposing the substrate with the catalyst layer on the metal bottom of the feature to an anisotropic etch to remove any catalyst from the dielectric.

10. The method of claim 8 , wherein the metal film has a growth rate of about 0.8 Å / cycle or greater.

11. 10. The method of claim 1, further comprising washing the first metal at the bottom of the feature to remove oxides from the first metal prior to exposure to the metal precursor and alkyl halide catalyst.

12. 1. A method of forming a seamless gap fill, comprising: depositing a second metal film within a feature on a substrate to partially fill the feature with the second metal film, the feature having a bottom and at least one dielectric sidewall, the bottom comprising a first metal, the first metal comprising a first metal material, the first metal having a first metal surface exposed within the feature, the at least one dielectric sidewall having a top surface outside the feature and one or more dielectric sidewall surfaces within the feature, the second metal film comprising a second metal material, the second metal film forming directly and selectively on the first metal surface compared to the one or more dielectric sidewall surfaces within the feature, and the second metal film having a top surface below the top surface of the at least one dielectric sidewall; depositing a liner on the one or more dielectric sidewall surfaces within the feature up to above the second metal film; filling the feature with the second metallic material to cover the top surface of the liner and the at least one dielectric sidewall; removing the second metal film and a portion of the dielectric and at least a portion of the liner to form a seamless gap fill; forming a blocking layer on the top surface of the second metal film before depositing the liner, the blocking layer preventing the liner from forming on the top surface of the second metal film; The method further comprising, after forming the liner and before filling the feature with the second metal material, removing the blocking layer from the top surface of the second metal film.

13. 13. The method of claim 12, further comprising annealing the second metal film after filling the feature with the second metal material and before removing the second metal material from the top surface of the at least one dielectric sidewall.

14. 13. The method of claim 12, wherein the first metallic material comprises one or more of cobalt, tungsten, ruthenium, or molybdenum, and the second metallic material comprises one or more of tungsten, ruthenium, or molybdenum.

15. 1. A method of forming a seamless gap fill, comprising: (a) cleaning a bottom of a feature in a substrate, the feature including a bottom and at least one dielectric sidewall, the bottom including a first metal, the first metal having a first metal surface exposed within the feature, and the at least one dielectric sidewall having a top surface outside the feature and one or more dielectric sidewall surfaces within the feature; (b) selectively depositing a ruthenium film within the feature directly onto the first metal surface relative to the one or more dielectric sidewall surfaces within the feature, the ruthenium film partially filling the feature such that a top surface of the ruthenium film is below the top surface of the at least one dielectric sidewall; (c) selectively forming a blocking layer on the top surface of the ruthenium film; (d) forming a conformal liner on the one or more dielectric sidewall surfaces and the top surface of the at least one dielectric sidewall, the conformal liner being substantially free of the top surface of the ruthenium film; (e) removing the blocking layer from the top surface of the ruthenium film; (f) filling the feature with the ruthenium to cover the one or more dielectric sidewall surfaces and the conformal liner on the top surface of the at least one dielectric sidewall; (g) annealing the ruthenium film; (h) removing the ruthenium film and a portion of the dielectric, and at least a portion of the liner to form a seamless ruthenium gapfill.

Images