Gap fill method using catalytic deposition

Abstract

Methods of depositing a metal film are discussed. The metal film is formed on a bottom of a feature having a metal bottom and a dielectric sidewall. The formation of the metal film includes exposure to a metal precursor and an alkyl halide catalyst while the substrate is maintained at a deposition temperature. The metal precursor has a decomposition temperature that is higher than the deposition temperature. The alkyl halide includes carbon and a halogen, and the halogen includes bromine or iodine.

Description

Technical Field

[0001] Generally, embodiments of this disclosure relate to methods for depositing metal films. Some embodiments of this disclosure relate to methods for depositing metal films. Some embodiments of this disclosure relate to the selective deposition of metal films. Some embodiments of this disclosure control the deposition location and / or rate by using plasma and / or thermal exposure conditions. Background Technology

[0002] Driven by the demand for mobile and high-performance systems from emerging industries such as self-driving cars, virtual reality, and future mobile devices, the semiconductor industry continues its efforts to achieve continuous miniaturization of devices. To accomplish this feat, new high-performance materials are needed to circumvent the inherent engineering, chemical, and physical challenges encountered in rapidly shrinking features in microelectronic devices.

[0003] Ruthenium is proposed as a novel integration material due to its high melting point (capable of withstanding high current densities), excellent density, and current conductivity. Ruthenium and ruthenium-containing thin films possess attractive material and conductivity properties. Ruthenium films have been proposed for applications ranging from the front-end to the back-end of semiconductor and microelectronic devices.

[0004] Due to the inherent ability of thin film deposition techniques such as chemical vapor deposition (CVD) and atomic layer deposition (ALD) to deposit materials in a high-throughput and precise manner, these techniques are ideal for depositing ruthenium thin films.

[0005] However, the deposited ruthenium films typically differ from bulk ruthenium materials. Depositing high-purity (>99 atomic% Ru) ruthenium films is particularly challenging, especially as an interstitial filler. Previous solutions utilizing oxygen reactants produce films that are rougher than those using bulk materials. Similarly, hydrogen reactants generate more impurities, requiring subsequent annealing steps to remove them. Finally, plasma deposition processes cannot deposit interstitial fillers without creating gaps and may damage the underlying substrate.

[0006] In current technologies, structures are filled using CVD or electrochemical electroplating (ECP) processes. In CVD processes where deposition occurs across the entire structure, voids are often formed when the film coalesces due to roughness, leaving gaps within these voids. ECP processes are limited by factors such as size and the availability of processing options for the desired material.

[0007] Therefore, there is a need for methods and materials for depositing high-purity conformal ruthenium films as interstitial fillers. Furthermore, there is a need for methods and materials for depositing ruthenium films as interstitial fillers in the absence of gaps or voids.

[0008] Furthermore, with the development of semiconductor device design, the precision materials manufacturing in the semiconductor industry has entered the era of the atomic scale. At the atomic scale, with only a few dozen atoms, there is virtually no room for error. This unprecedented challenge demands new materials handling technologies with atomic-level precision. However, increasing the complexity of the processing steps required for atomic-scale device manufacturing significantly reduces yield and increases manufacturing costs.

[0009] Selective deposition techniques offer the potential for chemically selective atomic layer precision in semiconductor film patterning. Selective deposition also offers the potential to simplify processing flows by eliminating photolithography or other processes.

[0010] Selective deposition of materials can be achieved in various ways. For example, some processes may be based on the inherent selectivity of a surface due to its surface chemistry. These processes are quite rare and typically require surfaces with extremely different surface energies, such as metals and dielectrics.

[0011] Therefore, there is a need for methods to selectively deposit metal films on metal surfaces in a manner even more favorable than on dielectric surfaces, or vice versa.

[0012] Furthermore, existing devices use tungsten films for memory and logic applications. Tungsten film deposition is typically performed at relatively high temperatures, which can be limited by the thermal budget of the resulting device. Fluorine-containing compounds are often used to deposit tungsten films. Fluorine is generally undesirable in the deposition process due to its reactive and adverse effects. To prevent fluorine from reacting with the underlying layer, a relatively thick barrier layer is used. Barrier layer deposition reduces the thermal budget and yield.

[0013] Therefore, there is a need in this field for conductive materials that do not use fluorine and / or can be deposited at low temperatures.

[0014] Furthermore, during middle-of-line (MOL) processing, the goal is to minimize the via resistance of the MOL structure. Padding materials are typically required to enhance the adhesion of the metal (e.g., ruthenium) to the dielectric material for post-processing steps such as chemical mechanical planarization (CMP). However, the presence of the padding increases the via resistance. Therefore, a gap-filling process with reduced via resistance is needed for MOL applications in this art. Summary of the Invention

[0015] One or more embodiments of this disclosure relate to a metal deposition method. A substrate having at least one feature, comprising 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, wherein the halogen comprises bromine or iodine.

[0016] Additional embodiments of this disclosure relate to a method for forming a seamless gap fill. A second metal film is deposited in a feature on a substrate to partially fill the feature using the second metal film. The feature includes a bottom and at least one sidewall. The bottom includes a first metal, and the 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 the top surface of the second metal film is lower than the top surface of the dielectric. A pad is deposited on the sidewall of the feature above the second metal film. The feature is filled using the second metal film to cover the top surfaces of the pad and the dielectric. The second metal film and at least some of the pad are removed from the top surface of the dielectric, and at least some of the dielectric is removed to form a seamless gap fill.

[0017] Further embodiments of this disclosure relate to a method for forming a seamless gap fill. The method includes the steps of: (a) optionally cleaning the surface of a first metal at the bottom of a feature in a substrate, the feature including at least one dielectric sidewall; (b) selectively depositing a ruthenium film on the first metal in the feature relative to the dielectric sidewall, the ruthenium film partially filling the feature such that the top surface of the ruthenium film is lower than the top surface of the dielectric; (c) optionally selectively forming a barrier layer on the top surface of the ruthenium film; (d) forming conformal pads on the dielectric sidewall and the top surface of the dielectric, the conformal pads not substantially formed on the top surface of the ruthenium film; (e) optionally removing the barrier layer from the top surface of the ruthenium film; (f) filling the feature with the ruthenium film to cover the conformal pads on the dielectric sidewall and the top surface of the dielectric; (g) annealing the ruthenium film; and (h) removing a portion of the ruthenium film and the dielectric, and removing at least some of the pads to form a seamless ruthenium gap fill. Attached Figure Description

[0018] Therefore, the above-described features of this disclosure can be understood in detail by referring to the embodiments to obtain a more specific description of the disclosure briefly summarized above, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only show typical embodiments of this disclosure and should not be considered as limiting the scope, as other equivalent embodiments are permissible.

[0019] Figure 1 A schematic diagram showing a processing platform according to one or more embodiments of this disclosure;

[0020] Figure 2 Showing a cross-sectional view of a batch processing chamber according to one or more embodiments of the present disclosure;

[0021] Figure 3 Showing a partial perspective view of a batch processing chamber according to one or more embodiments of the present disclosure;

[0022] Figure 4 A schematic diagram showing a batch processing chamber according to one or more embodiments of the present disclosure;

[0023] Figure 5 A schematic diagram showing a portion of a wedge-shaped gas distribution assembly for a batch processing chamber according to one or more embodiments of the present disclosure;

[0024] Figure 6 A schematic diagram showing a batch processing chamber according to one or more embodiments of the present disclosure;

[0025] Figure 7 An example processing sequence for forming a metal layer using a two-pulse cyclic deposition technique is illustrated according to one or more embodiments of this disclosure;

[0026] Figure 8 An example processing sequence for forming a ruthenium layer is illustrated according to one or more embodiments of this disclosure;

[0027] Figure 9 Showing a cross-sectional view of an example substrate according to one or more embodiments of this disclosure;

[0028] Figures 10A to 10D An example substrate illustrating processing during one or more embodiments of this disclosure; and

[0029] Figure 11 An example method for seamless gap filling is illustrated according to one or more embodiments of this disclosure.

[0030] In the accompanying drawings, similar parts and / or features may have the same reference numerals. Furthermore, various parts of the same type can be distinguished by a dash following the reference numerals and a second reference numeral used to differentiate similar parts. If only the first reference numeral is used in the description, the description applies to any similar part having the same first reference numeral, regardless of what the second reference numeral is. Detailed Implementation

[0031] Before describing several exemplary embodiments of this disclosure, it should be understood that this disclosure is not limited to the details of the construction or processing routines set forth in the following description. This disclosure can have other embodiments and can be practiced or implemented in various ways.

[0032] As used herein, the terms “substrate,” “substrate surface,” or similar terms refer to any substrate on which processing is performed or the surface of material formed on a substrate. For example, depending on the application, substrate surfaces on which processing is performed may 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). Substrates may include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes such as polishing, etching, reduction, oxidation, hydroxylation (or generating or grafting target chemical moieties to impart chemical functionality), annealing, and / or baking of the substrate surface. In addition to processing directly on the surface of the substrate itself, any film processing procedures disclosed herein (disclosed in more detail below) may also be performed on an underlayer formed on the substrate, and the term “substrate surface” is intended to include such underlayers as referred to herein. Therefore, for example, when a film / layer or part of a film / layer has been deposited onto a substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface. What a given substrate surface contains will depend on the material to be deposited and the specific chemicals used.

[0033] As used herein, “atomic layer deposition” or “cyclical deposition” refers to the sequential exposure of two or more reactive compounds to deposit a material layer on a substrate surface. As used in this specification and the appended claims, the terms “reactive compound,” “reactive gas,” “reactive species,” “precursor,” and “processing gas” are used interchangeably to refer to a substance having a species capable of reacting with the substrate surface or with materials on the substrate surface in a surface reaction (e.g., chemisorption, oxidation, reduction). The substrate or portions thereof are respectively exposed to two or more reactive compounds introduced into the reaction zone of a processing chamber. In a time-domain ALD process, the exposure to each reactive compound is time-delayed to allow each compound to adhere to and / or react on the substrate surface, and then be removed from the processing chamber. These reactive compounds are referred to as being sequentially exposed on the substrate. In spatial ALD processes, different portions of a substrate surface or different 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 exposed to more than one reactive compound at the same time. As used in this specification and the appended claims, and as those skilled in the art will understand, the term "substantially" in this context means that a very small portion of the substrate may be simultaneously exposed to multiple reactive gases due to diffusion, and that such simultaneous exposure is unintentional.

[0034] In one aspect of time-domain ALD processing, 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) can be introduced into the processing chamber to purge the reaction zone or remove any residual reactive compounds or reaction byproducts. Alternatively, the purge gas can flow continuously throughout the deposition process, such that only the purge gas flows during the time delays between pulses of the reactive compounds. The reactive compounds are pulsed alternately until a desired film or film thickness is formed on the substrate surface. In either case, the ALD process of pulsed delivery of compound A, purge gas, compound B, and purge gas is a cycle. A cycle can begin with compound A or compound B and continue the respective sequences until a film with a predetermined thickness is obtained.

[0035] In an embodiment of spatial ALD processing, a first reactive gas and a second reactive gas (e.g., a metal precursor gas) are simultaneously delivered to the reaction zone, but separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas delivery equipment such that any given point on the substrate is exposed to both the first and second reactive gases.

[0036] As used in this specification and the accompanying claims, the terms “precursor,” “reactant,” “reactive gas,” etc., are used interchangeably to refer to any gaseous species that can react with the substrate surface.

[0037] Some embodiments of this disclosure relate to a process using a reaction chamber with multiple gas ports for introducing different chemical or plasma gases. Spatially, these gas ports (also referred to as channels) are separated by inert purge gases and / or vacuum evacuation ports to create gas curtains, minimizing or eliminating mixing of gases from different ports to avoid unwanted gas-phase reactions. A wafer moving through these spatially separated ports receives sequential and multiple surface exposures to different chemical or plasma environments, resulting in layer-by-layer film growth or surface etching in a spatial ALD mode. In some embodiments, the processing chamber has a modular architecture on the gas distribution components, and each modular component has independent parameter controls (e.g., RF or gas flow) to provide control flexibility, such as gas flow and / or RF exposure.

[0038] Some embodiments of this disclosure provide methods for depositing high-purity metal films. The methods of various embodiments use atomic layer deposition (ALD) to provide pure or near-pure metal films. While exemplary embodiments of this disclosure mention the deposition of ruthenium, it should be understood that the principles of this disclosure can deposit high-purity metal films, regardless of the metal.

[0039] Some embodiments of this disclosure provide a method for selectively depositing a metal film on a metal surface in a manner more favorable than on a dielectric surface. Some embodiments of this disclosure provide a method for selectively depositing a metal film on a dielectric surface in a manner more favorable than on a metal surface. The term "selectively depositing a film on one surface in a manner more favorable than on another surface," as used in this specification and the appended claims, means depositing a first amount of film on a first surface and depositing a second amount of film on a second surface, wherein the second amount of film is less than the first amount of film, or no film is deposited on the second surface.

[0040] The term "over" as used here does not imply a physical orientation of one surface on top of another, but rather a thermodynamic or kinetic relationship of the chemical reactions of one surface relative to the other. For example, selectively depositing a metal film on a metal surface in a manner more favorable than on a dielectric surface means that a metal film is deposited on the metal surface, and less or no metal film is deposited on the dielectric surface; or that a metal film is thermodynamically or kinetically more likely to form on the metal surface than on the dielectric surface.

[0041] The selectivity of deposition treatments is generally expressed as a multiple of the growth rate. For example, if the growth (or deposition) rate of one surface is 25 times that of another surface, the treatment would be described as having a selectivity of 25:1. In this sense, a higher ratio indicates a more selective treatment.

[0042] Some embodiments of this disclosure advantageously provide methods for depositing high-purity metal films. Consequently, these high-purity films exhibit properties similar to those of the bulk metal materials associated with them. For example, some embodiments of this disclosure provide ruthenium films that are smoother and have lower resistivity than ruthenium films deposited by conventional oxygen or hydrogen reactants. Some embodiments of this disclosure advantageously provide gapless, conformally filled metal films.

[0043] Some embodiments of this disclosure advantageously provide the selective deposition of high-purity metal films on metal surfaces in a manner more favorable than on dielectric surfaces. For example, selectively depositing a metal (e.g., ruthenium) on copper in a manner more favorable than on dielectric surfaces advantageously provides a copper overlay layer without additional etching or photolithography steps. Furthermore, selective deposition can also fill gaps from bottom to top in features (e.g., trenches, vias) with metal contacts on the bottom and dielectric sidewalls.

[0044] Some embodiments of this disclosure advantageously provide the selective deposition of high-purity metal films on dielectric surfaces in a manner even more favorable than on metal surfaces. For example, selectively depositing metal on a dielectric advantageously provides a metal layer on a barrier or other dielectric in downstream applications.

[0045] Some embodiments of this disclosure utilize spatial ALD processing, which is executed on a processing platform as disclosed herein. Referring to the figures, Figure 1 A processing platform 100 according to one or more embodiments of the present disclosure is shown. Figure 1 The embodiments shown represent only one possible configuration and should not be considered as limiting the scope of the disclosure. For example, in some embodiments, the processing platform 100 has different numbers of processing chambers, buffer chambers, and robot configurations.

[0046] Processing platform 100 includes a central transfer station 110, which has multiple sides 111, 112, 113, 114, 115, and 116. The central transfer station 110 shown has 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. Although six sides are shown, those skilled in the art will understand that, depending on, for example, the overall configuration of processing platform 100, the central transfer station 110 may have any suitable number of sides.

[0047] The transfer station 110 has a robot 117 positioned therein. The robot 117 can be any suitable robot capable of moving the wafer during processing. In some embodiments, the robot 117 has a first arm 118 and a second arm 119. The first arm 118 and the second arm 119 can move independently of the other arms. The first arm 118 and the second arm 119 can move in the xy plane and / or along the z-axis. In some embodiments, the robot 117 includes a third arm or a fourth arm (not shown). Each arm can move independently of the other arms.

[0048] The 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 in a batch. In some embodiments, the first batch processing chamber 120 can be configured to process a range of approximately 4 (x=4) to approximately 12 (x=12) wafers simultaneously. In some embodiments, the first batch processing chamber 120 is configured to process six (x=6) wafers simultaneously. As those skilled in the art will understand, although the first batch processing chamber 120 can process multiple wafers between the loading / unloading of a single wafer, each wafer can experience different processing conditions at any given time. For example, such as... Figures 2 to 6 The spatial atomic layer deposition chamber shown exposes the wafer to different processing conditions in different processing regions, so that processing is completed as a wafer moves through each region.

[0049] Figure 2 The diagram shows a cross-section of a processing chamber 200, which includes a gas distribution assembly 220 (also referred to as an injector or injector assembly) and a base assembly 240. The gas distribution assembly 220 is any type of gas delivery device used in the processing chamber. The gas distribution assembly 220 includes a front surface 221 facing the base assembly 240. The front surface 221 may have any number or type of openings to deliver a gas flow toward the base assembly 240. The gas distribution assembly 220 also includes an outer peripheral edge 224, which, in the illustrated embodiment, is substantially circular.

[0050] The specific type of gas distribution assembly 220 used can vary depending on the specific process being used. Embodiments of this disclosure can be used with any type of processing system where the gap between the base and the gas distribution assembly is controlled. While various types of gas distribution assemblies (e.g., spray heads) can be employed, embodiments of this disclosure may be particularly useful for spatial gas distribution assemblies having multiple substantially parallel gas channels. The term "substantially parallel" as used in this specification and the appended claims means that the elongated axes of the gas channels extend in the same general direction. Slight imperfections may exist in the parallelism of the gas channels. In a binary reaction, the multiple substantially parallel gas channels may 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. Gases exiting from the (multiple) first reactive gas A channels, (multiple) second reactive gas B channels, and (multiple) purge gas P channels are directed toward the top surface of the wafer. Some gas flows horizontally across the surface of the wafer and exit the processing area via the (multiple) purge gas P channels. The substrate moving from one end of the gas distribution assembly to the other end is sequentially exposed to each processing gas, and a layer is formed on the substrate surface.

[0051] In some embodiments, the gas distribution assembly 220 is a rigid, fixed body made of a single injector unit. In one or more embodiments, such as Figure 3 As shown, the gas distribution assembly 220 is made of multiple independent segments (e.g., injector units 222). Both single-piece and multi-segment assemblies can be used with the various embodiments of this disclosure described herein.

[0052] The base assembly 240 is disposed below the gas distribution assembly 220. The base assembly 240 includes a top surface 241 and at least one recess 242 in the top surface 241. The base assembly 240 also has a bottom surface 243 and an edge 244. The at least one recess 242 can be of any suitable shape and size, depending on the shape and size of the substrate 60 being processed. Figure 2 In the illustrated embodiment, the groove 242 has a flat bottom to support the bottom of the wafer; however, the bottom of the groove can vary. In some embodiments, the groove has a stepped region around its outer peripheral edge, the stepped region being sized to support the outer peripheral edge of the wafer. The amount of the outer peripheral edge of the wafer supported by the steps can vary depending on, for example, the thickness of the wafer and features already present on the back side of the wafer.

[0053] In some implementations, such as Figure 2 As shown, the groove 242 in the top surface 241 of the base assembly 240 is sized such that the substrate 60 supported in the groove 242 has a top surface 61 that is substantially coplanar with the top surface 241 of the base 240. In this specification and the appended claims, the term "substantially coplanar" means that the top surface of the wafer and the top surface of the base 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.

[0054] Figure 2 The base assembly 240 includes a support column 260, which is capable of raising, lowering, and rotating the base assembly 240. The base assembly may include a heater, gas piping, or electronic components within the center of the support column 260. The support column 260 can be a primary means of increasing or decreasing the gap between the base assembly 240 and the gas distribution assembly 220, or of moving the base assembly 240 to a suitable position. The base assembly 240 may also include a fine-tuning actuator 262, which can make fine adjustments to the base assembly 240 to create a predetermined gap 270 between the base assembly 240 and the gas distribution assembly 220.

[0055] In some embodiments, the gap 270 distance 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.

[0056] The processing chamber 200 shown in the figure is a rotary chamber, in which the base assembly 240 can hold multiple substrates 60. Figure 3 As shown, the gas distribution assembly 220 may include a plurality of independent injector units 222, each capable of depositing a film on the wafer as it moves beneath the injector units. Two pie-shaped injector units 222 are shown positioned approximately on opposite sides of the base assembly 240 and above the base 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 may be included. In some embodiments, there are a sufficient number of pie-shaped injector units 222 to form a shape conforming to the shape of the base assembly 240. In some embodiments, each individual pie-shaped injector unit 222 may be moved, removed, and / or replaced independently without affecting any other injector units 222. For example, a segment may be raised to allow a robot to access the area between the base assembly 240 and the gas distribution assembly 220 to load / unload the substrate 60.

[0057] Processing chambers with multiple gas injectors can be used to process multiple wafers simultaneously, subjecting them to the same processing flow. For example, such as Figure 4As shown, the processing chamber 200 has four gas injector assemblies and four substrates 60. At the start of processing, the substrates 60 can be positioned between the gas distribution assemblies 220. Rotating the pedestal assembly 240 by 45° causes each substrate 60 between the gas distribution assemblies 220 to be moved to the gas distribution assembly 220 for film deposition, as indicated by the dashed circle below the gas distribution assembly 220. An additional 45° rotation will move the substrates 60 away from the gas distribution assembly 220. The number of substrates 60 and gas distribution assemblies 220 can be the same or different. In some embodiments, the number of wafers processed is the same as the number of gas distribution assemblies. In one or more embodiments, the number of wafers processed is a fraction or an integer multiple of the number of gas distribution assemblies. For example, if there are 4 gas distribution assemblies, then 4x wafers are processed, where x is an integer value greater than or equal to 1. In an exemplary embodiment, the gas distribution assembly 220 includes 8 processing regions separated by a gas curtain, while the pedestal assembly 240 can hold 6 wafers.

[0058] Figure 4 The processing chamber 200 shown represents only one possible configuration and should not be considered as limiting the scope of the disclosure. Here, the processing chamber 200 includes a plurality of gas distribution assemblies 220. In the illustrated embodiment, four gas distribution assemblies 220 (also referred to as injector assemblies) are evenly spaced around the processing chamber 200. The illustrated processing chamber 200 is octagonal; however, those skilled in the art will understand that this is a possible shape and should not be considered as limiting the scope of this disclosure. The illustrated gas distribution assembly 220 is trapezoidal, but may also be a single circular component or composed of multiple pie-shaped portions, such as... Figure 3 As shown.

[0059] Figure 4 The illustrated embodiment includes a loading and locking chamber 280 or an auxiliary chamber such as a buffer station. This chamber 280 is connected to one side of the processing chamber 200 to allow, for example, a substrate (also referred to as substrate 60) to be loaded / unloaded from the processing chamber 200. A wafer robot may be positioned within the chamber 280 to move the substrate onto a pedestal.

[0060] The rotation of the turntable (e.g., base assembly 240) can be continuous or intermittent (discontinuous). In continuous processing, wafers are continuously rotated, exposing them sequentially to the individual injectors. In discontinuous processing, wafers can be moved to an injector region and stopped, then moved to an inter-injector region 84 and stopped. For example, the turntable can rotate to move a wafer from the inter-injector region through the injectors (or stop near the injectors) and move to the next inter-injector region, where the turntable can pause again. Pauses between injectors can provide time for additional processing routines between layer depositions (e.g., exposure to plasma).

[0061] Figure 5 A segment or portion of the gas distribution assembly 220 is shown, which may be referred to as an injector unit. The injector unit 222 may be used alone or in combination with other injector units. For example, such as Figure 6 As shown, four Figure 5 The injector units 222 are combined to form a single gas distribution assembly 220. (For clarity, the lines separating the four injector units are not shown). Although Figure 5 The injector unit 222 has both a first reactive gas port 225 and a second gas port 235 in addition to the purge gas port 255 and the vacuum port 245, but the injector unit 222 does not require all of these components.

[0062] Please refer to Figure 5 or Figure 6 Both, according to one or more embodiments, the gas distribution assembly 220 may include multiple segments (or injector units 222), wherein the segments may be identical or different. The gas distribution assembly 220 is positioned within a processing chamber and includes multiple elongated gas ports 225, 235, 245 on its front surface 221. The multiple elongated gas ports 225, 235, 245, 255 extend from a region adjacent to the inner peripheral edge 223 to a region adjacent to the outer peripheral edge 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.

[0063] When describing a port extending from at least approximately the inner perimeter to at least approximately the outer perimeter, refer to... Figure 5 or Figure 6In the illustrated embodiment, however, the ports may extend radially not only from the inner peripheral region to the outer peripheral region. When the vacuum port 245 surrounds the reactive gas ports 225 and 235, these ports may extend tangentially. Figure 5 or Figure 6 In the embodiment shown, all edges of the wedge-shaped reactive gas ports 225, 235, including the edges of the adjacent inner and outer peripheral regions, are surrounded by the vacuum port 245.

[0064] Please refer to Figure 5 As the substrate moves along path 227, various portions of the substrate surface are exposed to various reactive gases. Along path 227, the substrate will be exposed to, or "see," the purge gas port 255, the vacuum port 245, the first reactive gas port 225, the vacuum port 245, the purge gas port 255, the vacuum port 245, the second gas port 235, and the vacuum port 245. Therefore, in Figure 5 At the end of path 227 shown, the substrate has been exposed to a first reactive gas and a second reactive gas to form a layer. The injector unit 222 shown is formed in the shape of a quarter circle, but can be larger or smaller. Figure 6 The gas distribution assembly 220 shown can be considered as four units connected in series. Figure 5 The combination of injector unit 222.

[0065] Figure 5 The injector unit 222 shows a gas curtain 250 separating the reactive gases. The term "gas curtain" is used to describe any combination of gas streams or vacuum that separates the reactive gases from mixing. Figure 5 The illustrated gas curtain 250 includes a portion of vacuum port 245 adjacent to the first reactive gas port 225, a central purge gas port 255, and a portion of vacuum port 245 adjacent to the second gas port 235. This combination of gas flow and vacuum can be used to prevent or reduce the gas-phase reaction between the first and second reactive gases.

[0066] Please refer to Figure 6 The combination of airflow and vacuum from the gas distribution assembly 220 forms partitions within multiple processing zones 350. The processing zones are generally defined around individual gas ports 225, 235, while the gas curtain 250 is located between 350. Figure 6 The illustrated embodiment comprises eight independent processing zones 350, with eight independent air curtains 250 between them. A processing chamber may have at least two processing zones. In some embodiments, there are at least three, four, five, six, seven, eight, nine, ten, eleven, or twelve processing zones.

[0067] During processing, the substrate may be exposed to more than one processing area 350 at any given time. However, portions exposed to different processing areas are separated by an air curtain. For example, if the leading edge of a substrate enters the processing area including the second gas port 235, the middle portion of the substrate will be under the air curtain 250, while the trailing edge of the substrate will be in the processing area including the first reactive gas port 225.

[0068] The factory interface shown in the diagram (e.g.) Figure 4 (As shown) Connecting to the processing chamber 200, the factory interface may be, for example, a loading locking chamber 280. The substrate 60 is shown stacked on the gas distribution assembly 220 to provide a reference frame. The substrate 60 is typically held near the front surface 221 of the gas distribution assembly 220 by resting on a base assembly. The substrate 60 is loaded into the processing chamber 200 via the factory interface and is loaded onto a substrate support or base assembly (see...). Figure 4 The substrate 60 can be shown as being positioned within the processing area because it is located near the first reactive gas port 225 and between the two gas curtains 250a and 250b. Rotating the substrate 60 along path 227 will cause the substrate to move counterclockwise around the processing chamber 200. Therefore, the substrate 60 will be exposed to the first processing area 350a through the eighth processing area 350h, including all processing areas in between.

[0069] Some embodiments of this disclosure relate to a processing chamber 200 having multiple processing zones 350a to 350h, each processing zone being separated from adjacent zones by an air curtain 250. For example, Figure 6 The processing chamber is shown. The number of air curtains and processing zones within the processing chamber depends on the airflow arrangement and can be any suitable number. Figure 6 The embodiment shown has eight air curtains 250 and eight processing zones 350a to 350h.

[0070] Please refer back to this. Figure 1 The processing platform 100 includes a treatment chamber 140 connected to a second side 112 of the central transfer station 110. In some embodiments, the treatment chamber 140 is configured to expose the wafer to processing before and / or after processing in the first batch of processing chambers 120. In some embodiments, the treatment chamber 140 includes an annealing chamber. The annealing chamber may be a furnace annealing chamber or a rapid thermal annealing chamber, or a different chamber configured to hold the wafer at a predetermined temperature and pressure and provide a gas flow to the chamber.

[0071] In some embodiments, the processing platform further includes a second batch processing chamber 130 connected to a third side 113 of the central transfer station 110. The second batch processing chamber 130 may be configured similarly to the first batch processing chamber 120, or it may be configured to perform different processes or process different numbers of substrates.

[0072] The second batch processing chamber 130 may 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 processing on the same number of wafers within 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 (of the 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 the following: different numbers of wafers (x is not equal to y), different batch times, or both.

[0073] exist Figure 1 In the illustrated embodiment, the processing platform 100 includes a second processing chamber 150 connected to a fourth side 114 of the central transfer station 110. The second processing chamber 150 may be the same as or different from the processing chamber 140.

[0074] The processing platform 100 may include a controller 195 (connection not shown) connected to the robot 117. The controller 195 may be configured to move a wafer between the processing chamber 140 and the first batch processing chamber 120 using a first arm 118 of the robot 117. In some embodiments, the controller 195 is also configured to move a wafer between a second processing chamber 150 and a second batch processing chamber 130 using a second arm 119 of the robot 117.

[0075] In some embodiments, controller 195 is connected to base assembly 240 and gas distribution assembly 220 of processing chamber 200. Controller 195 may be configured to rotate base assembly 240 about a central axis. Controller may also be configured to control gas flow in gas ports 225, 235, 245, and 255. In some embodiments, first reactive gas port 225 provides flow of a metal precursor. In some embodiments, second reactive gas port 235 provides flow of reactants. In some embodiments, other gas ports (not indicated) may provide plasma flow. First reactive gas port 225, second reactive gas port 235, and other reactive gas ports (not indicated) may be arranged in any processing order.

[0076] 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 station may hold wafer cassettes that are processed and returned to their original cassettes, or the first buffer station 151 may hold unprocessed wafers that are moved to the second buffer station 152 after processing. In some embodiments, one or more buffer stations are configured to pre-process, preheat, or clean the wafers before and / or after processing.

[0077] In some embodiments, controller 195 is configured to move a wafer between a first buffer station 151 and one or more of a disposal chamber 140 and a first batch processing chamber 120 using a first arm 118 of robot 117. In some embodiments, controller 195 is configured to move a wafer between a second buffer station 152 and one or more of a second disposal chamber 150 or a second batch processing chamber 130 using a second arm 119 of robot 117.

[0078] The processing platform 100 may also include one or more slit valves 160 between the central transfer station 110 and any processing chamber. In the illustrated embodiment, there is one slit valve 160 between each of the processing chambers 120, 130, 140, 150 and the central transfer station 110. The slit valve 160 can be opened and closed to isolate the environment within the processing chamber from the environment within the central transfer station 110. For example, if a processing chamber generates plasma during processing, closing the slit valve of that processing chamber can help prevent stray plasma from damaging the robot within the transfer station.

[0079] In some embodiments, the processing chambers are not easily removed from the central transfer station 110. To allow maintenance on any processing chamber, each processing chamber may further include multiple access doors 170 located 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 illustrated embodiment, each processing chamber has an access door 170 on each side in addition to the side connected to the transfer station. Including so many access doors 170 complicates the structure of the processing chambers employed, as the hardware within the chambers will need to be configured to be accessible via the doors.

[0080] In some implementations, the processing platform includes a water tank 180 connected to a central transfer station 110. The water tank 180 can be configured to supply coolant to any or all of the processing chambers. Although referred to as a "water" tank, those skilled in the art will understand that any coolant can be used.

[0081] In some implementations, the size of the processing platform 100 allows for connection to house power via a single power connector 190. The single power connector 190 is attached to the processing platform 100 to provide power to the individual processing chambers and the central transfer station 110.

[0082] Processing platform 100 can be connected to factory interface 102 to load wafers or wafer cassettes into processing platform 100. Robot 103 within factory interface 102 can move wafers or cassettes into and out of buffer stations 151, 152. Wafers or cassettes can be moved within processing platform 100 by robot 117 within central transfer station 110. In some embodiments, factory interface 102 is a transfer station for another cluster tool.

[0083] In some embodiments, the processing platform 100 or the first-stage processing chamber 120 is connected to a controller. The controller may be the same controller 195 or a different controller. The controller may be connected to the base assembly and gas distribution assembly of the first-stage processing chamber 120 and may have one or more configurations. These configurations may include, but are not limited to: a first configuration that rotates the base assembly about a central axis, a second configuration that provides flow of metallic precursors to the processing area, a third configuration that provides flow of reactants to the processing area, and a fourth configuration that provides plasma in the processing area.

[0084] Figure 7 This disclosure describes a general method for forming a metal film on a substrate according to one or more embodiments. Method 700 typically begins at 702, wherein a substrate is provided and disposed within a processing chamber, wherein a metal film will be formed on the substrate. As used herein, "substrate surface" refers to any substrate surface on which layers may be formed. A substrate surface may have one or more features formed therein, one or more layers formed thereon, and combinations thereof. The substrate (or substrate surface) may be pretreated prior to the deposition of the metal film, for example by polishing, etching, reduction, oxidation, halogenation, hydroxylation, annealing, baking, etc.

[0085] The substrate can be any substrate on which materials 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 (e.g., a liquid crystal display (LCD), a plasma display, an electroluminescent (EL) lamp display), a solar array, a solar panel, a light-emitting diode (LED) substrate, a semiconductor wafer, etc. In some embodiments, one or more additional layers may be disposed on the substrate, allowing a metal film to be at least partially formed thereon. For example, in some embodiments, layers comprising metals, nitrides, oxides, or the like or combinations thereof may be located on the substrate, and a metal film may be formed on or on these layers.

[0086] At 703, the substrate is optionally exposed to a barrier compound. This treatment step will be described in more detail below and can facilitate selective control of deposition processes on substrates including both metallic and dielectric surfaces.

[0087] 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) or similar. In some embodiments, forming a metal film via cyclic deposition generally involves exposing the substrate to two or more process gases. In time-domain ALD embodiments, the exposure to each process gas is separated by a time delay / pause to allow components of the process gases to adhere to and / or react on the substrate surface. Alternatively or in combination, in some embodiments, the substrate may be purged before and / or after exposure to the process gases, wherein an inert gas is used for purge. For example, a first process gas may be provided to a process chamber, followed by purge with an inert gas. Subsequently, a second process gas may be provided to the process chamber, followed by purge with an inert gas. In some embodiments, an inert gas may be continuously provided to the process chamber, and the first process gas may be supplied to the process chamber in a dose- or pulsed manner, followed by a dose- or pulsed supply of the second process gas to the process chamber. In such embodiments, a delay or pause may occur between the doses of the first and second processing gases, thereby allowing a continuous flow of inert gas to purify the processing chamber between the doses of the processing gases.

[0088] In a spatial ALD implementation, exposure to the processing gases occurs simultaneously at different portions of the substrate, such that a portion of the substrate is exposed to a first reactive gas, while different portions of the substrate are exposed to a second reactive gas (if only two reactive gases are used). The substrate moves relative to the gas delivery system, such that points on the substrate are sequentially exposed to the first and second reactive gases. In any implementation of temporal or spatial ALD processing, the sequence can be repeated until a predetermined layer thickness is formed on the substrate surface.

[0089] As used herein, “pulse” or “dose” is intended to represent the amount of source gas introduced into the processing chamber intermittently or discontinuously. Depending on the duration of the pulse, the amount of a particular compound within each pulse may vary over time. A particular processing gas may include a single compound or a mixture / combination of two or more compounds, such as the processing gases described below.

[0090] The duration of each pulse / dose is variable and can be adjusted to suit, for example, the volumetric capacity of the processing chamber and the capability of the vacuum system connected to the processing chamber. Furthermore, the dose time of the processing gas can vary depending on the flow rate of the processing gas, the temperature of the processing gas, the type of control valve, the type of processing chamber used, and the ability of the components of the processing gas to adsorb onto the substrate surface. The dose time can also vary based on the type of layer being formed and the geometry of the device being formed. The dose time should be long enough to provide a sufficient volume of compound to adsorb / chemisorb onto substantially the entire surface of the substrate, forming a layer of processing gas components on said entire surface.

[0091] The process of forming a metal film at 704 can be initiated by exposing the substrate to a first reactive gas. The first reactive gas contains an alkyl halide and is exposed to the substrate for a first time period, as shown at 706.

[0092] Alkyl halides can be any suitable reactant to adsorb a halogen layer onto the substrate for subsequent reactions. 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 regard, the halogen insoluble in the metal film comprises less than or equal to about 2%, less than or equal to about 1%, or less than or equal to about 0.5% of the metal film on an atomic basis. In some embodiments, the alkyl halide has the general formula RX, wherein R is an alkyl, alkenyl, aryl, or other carbonaceous group. In some embodiments, R comprises one to two, one to four, or one to six carbon atoms. In some embodiments, the alkyl halide comprises iodoethane (H5C2I) or diiodomethane (CH2I2), or is substantially composed of iodoethane (H5C2I) or diiodomethane (CH2I2). In this regard, alkyl halides, substantially composed of the specified species in molar quantities, contain more than 95%, 98%, 99%, or 99.5% of the specified species, excluding any inert diluent gases.

[0093] Alkyl halides are delivered as alkyl halide-containing gases to the processing chamber. The alkyl halide-containing gas can be supplied 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, the following: 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 supplied at any suitable pressure, including but not limited to the following pressures: 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.

[0094] The exposure period of the substrate to the alkyl halide gas can be any suitable time required for the alkyl halide to form a sufficient adsorption layer on top of the substrate(s). For example, the process gas may flow 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 gas is exposed to the substrate surface for the following durations: in the range of about 0.1 seconds to about 90 seconds, or in the range of about 0.5 seconds to about 60 seconds, or in the range of about 1 second to about 30 seconds, or in the range of about 2 seconds to about 25 seconds, or in the range of about 3 seconds to about 20 seconds, or in the range of about 4 seconds to about 15 seconds, or in the range of about 5 seconds to about 10 seconds.

[0095] In some embodiments, the inert gas may be additionally supplied to the processing chamber simultaneously with the alkyl halide-containing gas. The inert gas may be mixed with the alkyl halide-containing gas (e.g., as a dilution gas) or supplied separately, and may be pulsed or supplied at a constant flow rate. 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 may be any inert gas, such as argon, helium, neon, or combinations thereof.

[0096] The temperature of the substrate can be controlled during deposition, for example, by setting the temperature of the substrate support or base. In some embodiments, the substrate is maintained at a temperature within the following ranges: from about 0°C to about 600°C, or from about 25°C to about 500°C, or from about 50°C to about 450°C, or from about 100°C to about 400°C, or from about 200°C to about 400°C, or from about 250°C to about 350°C. In some embodiments, the substrate is maintained below the decomposition temperature of the metal precursor. In some embodiments, the substrate is maintained 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.

[0097] In one or more embodiments, the substrate is maintained at a temperature less than or equal to about 400°C, or less than or equal to about 350°C, or less than about 300°C. In one or more embodiments, the substrate is maintained at a temperature greater than or equal to about 250°C, or greater than or equal to about 300°C, or greater than about 350°C. In some embodiments, the substrate is maintained at a temperature of about 280°C.

[0098] In addition to the above, additional processing parameters can be adjusted when the substrate is exposed to an alkyl halide-containing gas. For example, in some embodiments, the processing chamber can be maintained at a pressure of about 0.2 to about 100 Torr, or in the range of about 0.3 to about 90 Torr, or in the range of about 0.5 to about 80 Torr, or in the range of about 1 to about 50 Torr.

[0099] Next, at 708, an inert gas can be used to purge the processing chamber (especially in time-domain ALD). (This step may not be necessary in spatial ALD processing because of the presence of a gas curtain separating the reactive gases). The inert gas can be any inert gas, for example, argon, helium, neon, etc. In some embodiments, the inert gas may be the same as or different from the inert gas supplied to the processing chamber during the exposure of the substrate to the alkyl halide-containing gas at 706. In embodiments where the inert gas is the same, purge can be performed by: transferring the first processing gas from the processing chamber, allowing the inert gas to flow through the processing chamber, or purging any excess first processing gas components or reaction byproducts from the processing chamber. In some embodiments, the inert gas can be supplied at the same flow rate used in conjunction with the first processing gas as described above, or in some embodiments, the flow rate can be increased or decreased. For example, in some embodiments, the inert gas can be supplied to the processing chamber at a flow rate of about 0 to about 10,000 sccm to purge the processing chamber. In a spatial ALD, a purge gas curtain can be maintained between the flow of reactant gases, eliminating the need for a purge chamber. In some embodiments of spatial ALD processing, an inert gas can be used to purge the purge chamber or an area of ​​the purge chamber.

[0100] An inert gas flow can help remove any excess of the first process gas components and / or excess reaction byproducts from the processing chamber, preventing undesirable gas-phase reactions of the first and second process gases.

[0101] Next, at 710, the substrate is exposed to a second processing gas for a second time period. The second processing gas contains a metal precursor, which reacts with a halogen adsorption layer on the substrate surface to deposit a metal film. The second reactive gas may also be referred to as a metal precursor gas.

[0102] The metal precursor can be any suitable precursor to react with the halogen layer adsorbed on the 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.

[0103] The metal precursor can be any suitable precursor with a decomposition temperature higher than the deposition temperature. In some embodiments, the metal precursor substantially does not contain oxygen or nitrogen atoms. Therefore, in these embodiments, the metal precursor does not contain carbonyl ligands, oxoligands, amine ligands, or imine ligands. Within these parameters, the number and type of ligands on the metal precursor can be varied according to, for example, the oxidation state of the metal atoms. The metal precursor can be homooleptic or heterooleptic. In some embodiments, the metal precursor contains at least one ligand comprising an optionally alkyl-substituted cyclopentadiene (Cp) ring. In some embodiments, the metal precursor contains at least one ligand comprising an optionally alkyl-substituted benzene ring. In some embodiments, the metal precursor contains at least one isopropyltoluene (p-cymene) ligand. In some embodiments, the metal precursor contains at least one ligand comprising an open or closed diene. In some embodiments, the metal precursor contains at least one 1,3-butadiene ligand. In some embodiments, the metal precursor comprises at least one 1,5-hexadiene ligand. In some embodiments, the metal precursor comprises at least one aromatic ligand. In some embodiments, the at least one aromatic ligand comprises a benzene ring. In some embodiments, the benzene ring comprises at least one organic substituent comprising 1 to 6 carbon atoms. In some embodiments, the aromatic ligand comprises at least one ethylbenzene ligand. In some embodiments, the metal precursor comprises bis(ethylbenzene)molybdenum or is substantially composed of bis(ethylbenzene)molybdenum. In some embodiments, the metal precursor comprises isopropyltoluene ruthenium 1,5-hexadiene or is substantially composed of isopropyltoluene ruthenium 1,5-hexadiene.

[0104] The metal in the metal precursor corresponds to the metal in the deposited metal film. 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 in the metal precursor is 0. In other words, in some embodiments, the metal precursor comprises a zero-valent metal complex.

[0105] While exposing the substrate to the metal precursor gas, additional processing parameters can be adjusted. For example, in some embodiments, the processing chamber can be maintained at pressures of about 0.2 to about 100 Torr, or in the range of about 0.3 to about 90 Torr, or in the range of about 0.5 to about 80 Torr, or in the range of about 1 to about 50 Torr.

[0106] The metal precursor is delivered as a metal precursor gas to the processing chamber. The metal precursor gas can be supplied 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, the following: 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 metal precursor gas can be supplied at any suitable pressure, including but not limited to the following pressures: 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.

[0107] The exposure period of the substrate to the metal precursor gas can be any suitable time required for the metal precursor to react with the halogens adsorbed on the substrate surface. For example, the processing gas can be allowed to flow into the processing 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 the following durations: in the range of about 0.1 seconds to about 90 seconds, or in the range of about 0.5 seconds to about 60 seconds, or in the range of about 1 second to about 30 seconds, or in the range of about 2 seconds to about 25 seconds, or in the range of about 3 seconds to about 20 seconds, or in the range of about 4 seconds to about 15 seconds, or in the range of about 5 seconds to about 10 seconds.

[0108] In some embodiments, an inert gas may be additionally supplied to the processing chamber simultaneously with the metal precursor gas. The inert gas may be mixed with the metal precursor gas (e.g., as a diluent gas) or supplied alone, and may be pulsed or supplied at a constant flow rate. 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 may be any inert gas, such as argon, helium, neon, or a combination thereof.

[0109] Next, at 712, an inert gas can be used to purge the processing chamber. The inert gas can be any inert gas, for example, argon, helium, neon, etc. In some embodiments, the inert gas may be the same as or different from the inert gas supplied to the processing chamber during the previous processing routine. In embodiments using the same inert gas, purge can be performed by: transferring a second processing gas from the processing chamber, allowing the inert gas to flow through the processing chamber, or purging any excess second processing gas components or reaction byproducts from the processing chamber. In some embodiments, the inert gas can be supplied at the same flow rate used in conjunction with the second processing gas as described above, or in some embodiments, the flow rate can be increased or decreased. For example, in some embodiments, the inert gas can be supplied to the processing chamber at a flow rate greater than 0 to about 10,000 sccm to purge the processing chamber.

[0110] Although Figure 7 The general implementation of the processing method shown includes only two pulses of reactive gas, but it will be understood that this is merely exemplary and additional pulses of reactive gas may be used. In some implementations, the method is performed without using oxygen-containing reactive gas. The sub-process at 704 comprises a cycle. The reactive gas can be circulated in any order as long as it is isolated by the purification of the processing chamber. In some implementations, the deposition rate of the metal film is greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, greater than or equal to approximately / cycle, goods greater than or equal to approximately / cycle.

[0111] The deposition process is performed by thermal treatment without using plasma reactants. In other words, in some embodiments, the method is performed without using plasma.

[0112] Next, at 714, it is determined whether the metal film has reached a predetermined thickness. If the predetermined thickness has not been reached, method 700 returns to 704 to continue forming the metal film until the predetermined thickness is reached. Once the predetermined thickness is reached, method 700 can end or proceed to 716 for optional further processing (e.g., bulk deposition of another metal film). In some embodiments, a metal film may be deposited to form an overall layer thickness of approximately to approximately Or in some implementations, approximately to approximately Or in some implementations, approximately to approximately

[0113] In some embodiments, the metal layer contains greater than or equal to about 75 atomic percent of molybdenum, or greater than or equal to about 80 atomic percent of molybdenum, or greater than or equal to about 85 atomic percent of molybdenum, or greater than or equal to about 90 atomic percent of molybdenum, or greater than or equal to about 95 atomic percent of molybdenum.

[0114] In some embodiments, the metal layer contains less than or equal to about 10 atomic percent oxygen, or less than or equal to about 9 atomic percent oxygen, or less than or equal to about 8 atomic percent oxygen, or less than or equal to about 7 atomic percent oxygen, or less than or equal to about 6 atomic percent oxygen, or less than or equal to about 5 atomic percent oxygen, or less than or equal to about 4 atomic percent oxygen, or less than or equal to about 3 atomic percent oxygen.

[0115] In some embodiments, the metal layer contains iodine in the range of about 0.02 to about 5 atomic percent, or less than or equal to about 1 atomic percent.

[0116] In some embodiments, the metal layer contains less than or equal to about 20 atomic percent of carbon, or less than or equal to about 15 atomic percent of carbon, or less than or equal to about 10 atomic percent of carbon, or less than or equal to about 5 atomic percent of carbon.

[0117] In some embodiments, the metal layer comprises more than or equal to about 90 atomic percent molybdenum, less than or equal to about 3 atomic percent oxygen, less than or equal to about 1 atomic percent iodine and less than or equal to about 10 atomic percent carbon.

[0118] In some embodiments, the metal layer has a resistivity of less than or equal to about 40 μohm-cm, or less than or equal to about 35 μohm-cm, or less than or equal to about 30 μohm-cm, or less than or equal to about 25 μohm-cm, or less than or equal to about 20 μohm-cm. In some embodiments, the metal layer comprises molybdenum and has a resistivity of less than or equal to about 40 μohm-cm, or less than or equal to about 35 μohm-cm, or less than or equal to about 30 μohm-cm, or less than or equal to about 25 μohm-cm, or less than or equal to about 20 μohm-cm.

[0119] In some embodiments, the metal film is further treated by annealing. Without being bound by theory, it is believed that annealing the film in an argon (Ar) or hydrogen (H2) atmosphere at high temperatures reduces carbon and halogen impurities in the metal film. In some embodiments, the metal film is annealed in an atmosphere containing argon or hydrogen (H2) to reduce the atomic concentration of carbon and / or halogen impurities.

[0120] Metal films deposited through some embodiments are smoother than films deposited through known oxygen-based deposition processes. In some embodiments, the surface roughness of the metal film is less than or equal to about 10%, about 8%, about 5%, or about 2% of the thickness of the metal film.

[0121] The purity of the metal film is high. In some embodiments, the carbon content of the metal film, on an atomic basis, is less than or equal to about 2%, less than or equal to about 1%, or less than or equal to about 0.5% carbon. In some embodiments, the halogen content of the metal film, on an atomic basis, is less than or equal to about 1% or less than or equal to about 0.5% halogen. In some embodiments, the purity of the metal film, on an atomic basis, is greater than or equal to about 95%, greater than or equal to about 97%, greater than or equal to about 99%, greater than or equal to about 99.5%, or greater than or equal to about 99.9% metal atoms.

[0122] Some embodiments of this disclosure selectively deposit a first metal film on the second metal surface in a manner more favorable than on the first dielectric surface. These methods are similar to method 700 as described above, except that the provided substrate includes a first dielectric surface and a second metal surface. The first metal (of the metal film) and the second metal (of the 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, while the second metal is tungsten, cobalt, or copper.

[0123] 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, these materials are believed to react with alkyl halides and prevent halogen adsorption on the substrate surface, thereby catalyzing the reaction with the metal precursor. Therefore, even if present, only a small metal film is formed on the dielectric surface.

[0124] In some embodiments, the deposition temperature is below the decomposition temperature of the alkyl halide. Similarly, without being theoretically constrained, it is believed that if the alkyl halide decomposes, the halogen will be able to react with the metal precursor on all surfaces (regardless of their 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.

[0125] Some embodiments of this disclosure selectively deposit a first metal film on the first dielectric surface rather than on the second metal surface. These methods are similar to method 700 as described above, except that the provided substrate includes a first dielectric surface and a second metal surface, and the substrate is exposed to a barrier compound at 703.

[0126] At point 703, a substrate comprising at least a second metal surface and a second dielectric surface is exposed to a blocking compound. The blocking compound can be any suitable compound used to block deposits on the second metal surface. In some embodiments, the blocking compound contains at least one triple bond between two carbon atoms. In other words, in some embodiments, the blocking compound comprises an alkyne. In some embodiments, the blocking compound has the general formula R'≡R"". In some embodiments, R' and R" are identical. In some embodiments, R' and / or R" are alkyl or other carbonaceous groups. In some embodiments, the blocking compound comprises 4 to 12 carbon atoms. In some embodiments, R' and / or R" are straight chains. In some embodiments, R' and / or R" are branched chains. In some embodiments, the blocking compound comprises 3-hexyne.

[0127] The first metal (of the metal film) and the second metal (of the 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, while the second metal is tungsten, cobalt, or copper.

[0128] The first dielectric surface can be formed from any suitable dielectric material. In some embodiments, the dielectric material contains nitrogen or oxygen atoms.

[0129] 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 greater than or equal to about 250°C, greater than or equal to about 260°C, greater than or equal to about 270°C, greater than or equal to about 280°C, greater than or equal to about 290°C, or greater than or equal to about 300°C. In some embodiments, the deposition temperature is about 350°C.

[0130] As previously mentioned, without being bound by theory, these materials are believed to react with alkyl halides and prevent halogen adsorption on the substrate surface, thereby catalyzing the reaction with metal precursors. Therefore, even if present, only a small metal film is formed on the dielectric surface.

[0131] However, when the deposition temperature is higher than the decomposition temperature of the alkyl halide, halogen atoms are deposited across the entire substrate surface, thus depositing on the dielectric surface. In some embodiments, the metal surface is blocked by a barrier compound, resulting in very little metal film (if any) forming on the metal surface. Therefore, the deposition of the metal film is more selective for the dielectric surface than for the metal surface.

[0132] Generally, the deposition of high-purity metal films can be understood as follows: A substrate maintained at the deposition temperature is exposed to an alkyl halide (RX) to adsorb R and X onto the substrate, where R is a carbonaceous group and X is a halogen. R is expressed as RR or R... - The adsorption of X is completed, leaving X adsorbed on the substrate. The substrate is exposed to a metal precursor, ML, where M is a metal and L is a ligand. ML reacts with the adsorbed X to form MX on the substrate surface, releasing L. MX reacts with other MX groups to form MM. This reaction may produce XX or X. - XX can be desorbed and purified. - It may remain on the surface to further react with ML.

[0133] According to the inventors, this general mechanism relies on several premises. First, X is insoluble in M. Without theoretical constraints, the insolubility of X determines that X will not be present in a significant amount in the final metal film. Although it is possible to ignore this premise (e.g., using a halogen soluble in M), it is believed that using a halogen soluble in M ​​(X) would provide a metal film of lower purity. Second, in terms of bonding strength, ML is weaker than MX, and MX is weaker than MM. Again, without theoretical constraints, these thermodynamic relationships ensure that the above 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. Theoretically, if the metal precursor decomposes, the deposited film will contain a significant amount of the precursor ligand L, typically considered a carbon impurity.

[0134] The inventors have surprisingly discovered that processing, including metal precursors, alkyl halides, and processing conditions that meet all the above requirements, deposits high-purity metal films.

[0135] Furthermore, the inventors have surprisingly discovered that if the deposition temperature is below the thermal decomposition temperature of alkyl halides, the deposition process exhibits greater selectivity for metal surfaces than for dielectric surfaces, without the need for a barrier layer.

[0136] Furthermore, the inventors have surprisingly discovered that if the deposition temperature is at or above the thermal decomposition temperature of the alkyl halide, the deposition process can be made selective by exposing the metal surface to small alkyne barrier compounds.

[0137] Some embodiments of this disclosure advantageously provide a method for depositing a conformal metal film on a substrate comprising a high aspect ratio structure. As used herein, the term "conformal" means that the thickness of the metal film is uniform throughout the entire substrate surface. As used in this specification and the appended claims, the term "substantially conformal" means that the thickness of the metal film varies with respect to the average thickness of the film by no more than about 10%, 5%, 2%, 1%, or 0.5%. In other words, a substantially conformal metal film exhibits conformability greater than about 90%, 95%, 98%, 99%, or 99.5%.

[0138] One or more embodiments of this disclosure relate to memory devices comprising a molybdenum conductive layer. In some embodiments, the molybdenum conductive layer comprises more than or equal to about 90 atomic percent molybdenum, less than or equal to about 3 atomic percent oxygen, less than or equal to about 1 atomic percent iodine, and less than or equal to about 10 atomic percent carbon, and a resistivity of less than or equal to about 40 μohm-cm.

[0139] In some embodiments, a molybdenum conductive layer is formed on the barrier layer. In some embodiments, the thickness of the barrier layer is less than or equal to approximately or In some implementations, the molybdenum conductive layer is formed on the substrate without an intermediate barrier layer.

[0140] The above disclosure relates to metal film deposition via sequential pulses of reactants. The following disclosure relates to metal film deposition via simultaneous or constant-current processing. In some embodiments, the sequential pulse method is an ALD method. In some embodiments, the simultaneous or constant-current method is a CVD method. Although the processing steps differ, many reactants and processing parameters are similar.

[0141] Figure 8 A general method 800 for forming a metal film on a substrate is described according to one or more embodiments of the present disclosure. Figure 9 An example substrate for processing according to one or more embodiments of this disclosure is depicted. Method 800 generally begins at 810, providing a substrate 900 and placing the substrate 900 in a processing chamber, wherein a metal film will be formed on the substrate 900.

[0142] Please see Figure 9An example substrate 900 is shown. In some embodiments, substrate 900 has a substrate surface 905, in which at least one feature 910 is present. Feature 910 has sidewalls 912, 914 and a bottom 916. In some embodiments, dielectric material 920 forms the sidewalls 912, 914 and metallic material 930 forms the bottom 916. Those skilled in the art will recognize that the illustrated embodiments involve two sidewalls, as in a trench structure, but this disclosure is not limited to trenches. In some embodiments, the feature includes a circular via, which, technically, has a single circular sidewall, which is shown as two sidewalls in the illustrated cross-sectional view.

[0143] In some embodiments, substrate 900 may undergo one or more optional pretreatment steps. At 815, the substrate may optionally have one or more layers formed on the substrate surface.

[0144] In some embodiments, a metal nitride pad is deposited in feature 910. In some embodiments, the metal nitride pad comprises titanium nitride. In some embodiments, the thickness of the metal nitride pad is approximately... to approximately Within a certain range. In some embodiments, the thickness of the metal nitride pad is approximately... or about In some embodiments, no pad is formed in the feature prior to the formation of the metal film. In some embodiments, no pad is formed between the metal film and the bottom of the feature.

[0145] 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 thickness of the seed layer is 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 a known atomic layer deposition method. In some embodiments, the seed layer is deposited by an ALD cycle, the ALD cycle including ruthenium precursor exposure and alkyl halide exposure, and intermediate cleanup. In some embodiments, the seed layer is deposited by an ALD cycle, the ALD cycle including ruthenium precursor exposure and ammonia plasma exposure, and intermediate cleanup.

[0146] In some embodiments, the bottom 916 comprises metal, and optional pretreatment includes a cleaning process. In some embodiments, the metal bottom 916 of the feature is cleaned to remove oxides from the metal before a metal film is formed in the feature.

[0147] At 820, the substrate is optionally exposed to a barrier compound. This treatment step will be described in more detail below and can facilitate selective control of deposition processes on substrates including both metallic and dielectric surfaces.

[0148] At 830, a metal film is formed on the substrate. The metal film of some embodiments is formed by exposing the substrate to a metal precursor and an alkyl halide catalyst while maintaining the substrate at the deposition temperature. In some embodiments, the alkyl halide catalyst and the metal precursor are simultaneously exposed to the substrate. In some embodiments, the metal precursor and the alkyl halide catalyst are exposed to the substrate separately and sequentially. In the separately exposed embodiments, each “cycle” is a single exposure of the alkyl halide catalyst and the metal precursor in any order. The process of forming the metal film at 830 may begin by immersing the substrate in a catalytic gas. As shown at 840, the catalytic gas contains an alkyl halide and exposes the substrate for a first time period. In some embodiments, the catalytic gas contains an alkyl halide catalyst, which forms a catalyst layer on a characteristic metal substrate.

[0149] Alkyl halides can be any suitable reactant to adsorb a layer on the substrate for subsequent reactions. In other words, immersing the substrate in an alkyl halide forms an activated substrate surface. Alkyl halides are described above and elsewhere herein.

[0150] Alkyl halides can be supplied to the processing chamber in one or more pulses or continuously. In some embodiments, the alkyl halides are supplied together with an inert carrier gas, 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. Example flow rates and pressures disclosed elsewhere herein for alkyl halide-containing gases may also be applied in this embodiment.

[0151] The immersion period of the substrate in the alkyl halide can be any suitable amount of time required to allow the alkyl halide to form a sufficient adsorption layer on the substrate(s) surface(s). For example, the immersion period of the alkyl halide in the substrate can be greater than about 3 seconds or greater than about 5 seconds. In some embodiments, the immersion period is in the range of about 3 seconds to about 60 seconds.

[0152] In some embodiments, the inert gas may be additionally supplied to the processing chamber simultaneously with the alkyl halide-containing gas. The inert gas may be mixed with the alkyl halide (e.g., as a diluent gas) or supplied alone, and may be pulsed or supplied at a constant flow. The inert gas may be any inert gas, such as argon, helium, neon, or a combination thereof.

[0153] Next, at 850°C, the substrate is exposed to a second processing gas for a second time period. The second processing gas contains a metal precursor, which reacts with an adsorbed layer of alkyl halides or halogens on the substrate surface to deposit a metal film. The second reactive gas may also be referred to as a metal precursor gas.

[0154] The metal precursor can be any suitable precursor to react with the alkyl halide layer or halogen layer adsorbed on the substrate. Suitable metal precursors are described elsewhere in this document.

[0155] The metal precursor is delivered as a metal precursor gas to the processing chamber. The metal precursor gas can be supplied 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. Example values ​​for flow rate and pressure are described elsewhere in this document.

[0156] The exposure period of the substrate to the metal precursor gas can be any suitable time required for the metal precursor to react with the halogens adsorbed on the substrate surface. For example, the process gas can flow 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.

[0157] The temperature of the substrate can be controlled during exposure to the metal precursor, for example, by setting the temperature of the substrate support or base. This temperature is also referred to as the deposition temperature. In some embodiments, the substrate is maintained below the decomposition temperature of the metal precursor. In some embodiments, the substrate is maintained 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.

[0158] In one or more embodiments, the substrate is maintained at a temperature of less than or equal to about 400°C, or less than or equal to about 350°C, or less than or equal to about 300°C, or less than or equal to about 250°C, or less than or equal to about 200°C. In one or more embodiments, the substrate is maintained at a temperature of greater than or equal to about 150°C, or greater than or equal to about 200°C, or greater than or equal to about 250°C, or greater than or equal to about 300°C, or greater than or equal to about 350°C. In some embodiments, the substrate is maintained at a temperature of about 225°C or about 280°C.

[0159] The deposition process is performed by thermal treatment without the use of plasma reactants. In other words, the method is performed without the use of plasma.

[0160] Next, at 860, it is determined whether the metal film has reached a predetermined thickness. If the predetermined thickness has not been reached, method 800 returns to 850 to continue exposing the substrate to the metal precursor until the predetermined thickness is reached. Once the predetermined thickness is reached, method 800 may end or proceed to 870 for optional further processing. In some embodiments, the metal film may be deposited to form an overall layer thickness of approximately to approximately Or in some implementations, approximately to approximately Or in some implementations, approximately to approximately

[0161] Some embodiments of this disclosure selectively deposit a metal film on a metal surface in a manner superior to that on a first dielectric surface. These methods are similar to the method 800 described above. The provided substrate comprises a dielectric surface and a metal surface. In some embodiments, the processing is as follows: Figure 9 The substrate shown is configured to selectively form an upward gap filling on the metal surface at the bottom 916 of feature 910.

[0162] The metal in the metal film and the metal on 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, these materials are believed to react with alkyl halides and prevent halogen adsorption on the substrate surface, thereby catalyzing the reaction with the metal precursor. Therefore, even if present, only a small amount of metal film is formed on the dielectric surface.

[0163] In some embodiments, the deposition temperature is below the decomposition temperature of the alkyl halide. Similarly, without being theoretically constrained, it is believed that if the alkyl halide decomposes, the halogen will be able to react with the metal precursor on all surfaces (regardless of their 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.

[0164] Some embodiments of this disclosure advantageously provide methods for controlling the deposition of metal films. In some embodiments, the deposition rate is controlled. In some embodiments, the deposition location is controlled.

[0165] Various embodiments of the method utilize atomic layer deposition (ALD) or chemical vapor deposition (CVD) to form metal films. The above disclosure is relative to... Figure 7 A demonstrative ALD treatment is described and is targeted at Figure 8 A demonstrative CVD process is described.

[0166] As mentioned above, Figure 7 and Figure 8 The general deposition process shown is performed as a thermal treatment without the use of plasma reactants. The use and effects of plasma and other additional reactants will be discussed further below.

[0167] Some embodiments of this disclosure advantageously provide a method for depositing a metal film within a substrate feature or other structure. Example features or structures include, but are not limited to, trenches and vias.

[0168] Some embodiments of this disclosure advantageously provide deposition control methods for reducing film deposition on the exterior of a target feature and near feature openings. Without being theoretically constrained, it is believed that reducing deposition in these areas can lead to faster gap filling within the target feature and reduce clogging near feature openings and the formation of voids or crevices within the feature.

[0169] Please see Figure 7 and Figure 8 Without limiting the scope of the above disclosure, both the ALD and CVD processes utilize alkyl halides and metal precursors to deposit metal films. Without being theoretically constrained, alkyl halides are believed to act as catalysts in metal film deposition. Therefore, as specifically demonstrated by the CVD process, a single exposure of the substrate surface to alkyl halides can be used to deposit metal films with a thickness exceeding 10 nm.

[0170] Some embodiments of this disclosure advantageously provide a deposition control method for reducing the activity of a catalyst in a predetermined region on a substrate surface. In some embodiments, the catalyst activity is reduced. In some embodiments, the catalyst activity is eliminated.

[0171] Please see Figures 10A to 10D This shows an example substrate 400 during processing according to one or more embodiments of the present disclosure. Simplified for illustrative purposes. Figures 10A to 10D The illustrated substrate 1000. As described above and in Figure 9 As shown, in some embodiments, the substrate of this disclosure contains Figures 10A to 10D Features or structures not described in the text.

[0172] exist Figure 10A In this process, substrate 1000 includes substrate surface 1010. Figure 10B In this process, the substrate surface 1010 is exposed to alkyl halides to form an activated surface 1020. As described above, alkyl halides 1040 are adsorbed onto the substrate surface 1010 to form the activated substrate surface 1020.

[0173] exist Figure 10C In this process, a predetermined area of ​​the activated surface 1020 is exposed to a deactivation treatment to form a deactivated surface 1030. Figure 10B and Figure 10C The alkyl halide 1040 shown is depicted as round or oval; however, this is not intended to convey a specific molecular shape. Similarly, Figure 10B and Figure 10C The circle shown Figure 10C The differences between the oval shapes shown are only to express the activity and / or relative concentration of alkyl halides on the substrate surface.

[0174] exist Figure 10D In this process, substrate 1000 is exposed to a metal precursor to form a metal film 1050. For example... Figure 10D As shown, 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 deactivated surface 1030.

[0175] In some embodiments, the deactivation treatment reduces the concentration of alkyl halides on the activated surface 1020. In some embodiments, the deactivation treatment reduces the catalytic activity of the alkyl halides on the activated surface 1020.

[0176] In some implementations, the above regarding Figures 10A to 10D The described method has been modified to include a deactivation treatment prior to exposure to alkyl halides. In this context, deactivation treatment can be understood as “superactivating” a predetermined region of the substrate surface 1010 before exposure to alkyl halides. Once exposed to alkyl halides, the “superactivated” surface forms a higher concentration or activity of alkyl halides compared to the surface not exposed to the deactivation treatment. The difference in concentration and / or activity between surfaces can be used to control deposition. In some embodiments, as referenced above… Figures 10C to 10D As shown in the figure, the surface can be further deactivated.

[0177] Thickness T1 is greater than thickness T2. Therefore, some embodiments of this disclosure advantageously provide a deposition control method for controlling the amount of deposition in a predetermined region on a substrate surface.

[0178] In some embodiments, the T1:T2 ratio is greater than or equal to about 1:1, greater than or equal to about 2:1, greater than or equal to about 3:1, greater than or equal to about 4:1, greater than or equal to about 5:1, or greater than or equal to about 10:1. In some embodiments, little to no metal deposition occurs on the deactivation surface 1030. In other words, in some embodiments, the thickness T2 is approximately 0. In other words, the amount of metal film 1050 deposited on the deactivation surface 1030 is substantially negligible. The term "substantially negligible" as used in this regard means that the metal film on the deactivation surface covers less than 5%, less than 2%, less than 1%, or less than 0.5% of the deactivation surface.

[0179] The thickness of the metal film 1050 deposited on the activated surface 1020 and the deactivated surface 1030 is proportional to the deposition rate on the activated surface 1020 and the deactivated surface 1030. Therefore, some embodiments of this disclosure advantageously provide a deposition control method for controlling the deposition rate in a predetermined region of a substrate surface.

[0180] In some embodiments, the entire substrate surface is exposed to a deactivation process. Some embodiments of this disclosure can be used to control the deposition amount across the entire substrate. Some embodiments of this disclosure can be used to control the deposition rate across the entire substrate.

[0181] In some embodiments, not shown, the substrate 1000 includes one or more features. In some embodiments, the deactivation surface 1030 is a surface outside the one or more features. In some embodiments, the deactivation surface 1030 is a surface near the top of the sidewall of the one or more features.

[0182] Unbound by theory, it is believed that surfaces near substrate features and the top surfaces of the sidewalls of these features are highly activated (exhibiting larger deposition) due to the presence of multiple exposed surfaces nearby. Larger deposition on these surfaces increases the likelihood that the feature will be closed before a sufficient amount of film forms within the feature. When a feature is closed, gaps or pores tend to form. Therefore, in some embodiments, the deactivated surface 1030 is a surface near the top of one or more features. Furthermore, in some embodiments, the deactivated surface 1030 is a surface near the substrate feature. In some embodiments, the metal film deposited in the feature has reduced gaps or pores. In some embodiments, the metal film deposited in the feature is substantially seamless or pore-free. The term "substantially seamless" as used in this regard means that any gaps formed in the film between the sidewalls are less than about 1% of the cross-sectional area of ​​the sidewalls.

[0183] In some embodiments, a predetermined area of ​​the substrate is exposed to hydrogen gas instead of using plasma.

[0184] In some embodiments, a hydrogen pulse is introduced into the aforementioned ALD deposition cycle. In other words, the substrate may be exposed to the following pulse sequence: alkyl halide, purge, hydrogen, purge, metal precursor, purge. In some embodiments, after exposure to the metal precursor, the substrate is exposed to an additional hydrogen pulse, followed by purge. In some embodiments, after exposure to the alkyl halide, the substrate is exposed to an additional hydrogen pulse, followed by purge. In some embodiments, the purge phase between exposures to the metal precursor and / or alkyl halide is performed in some cycles, but not in all cycles.

[0185] In some embodiments, hydrogen exposure is introduced into the aforementioned CVD deposition cycle. In other words, the substrate may be immersed in an alkyl halide, exposed to hydrogen, and exposed to a metal precursor. In some embodiments, the substrate is exposed to hydrogen before being exposed to the metal precursor. In some embodiments, hydrogen and the metal precursor are flowed in simultaneously.

[0186] In some embodiments, a predetermined area of ​​the substrate is exposed to a plasma comprising one or more of hydrogen (H2), ammonia (NH3), or argon (Ar). In some embodiments, the plasma used to deactivate 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, about 50 W to about 300 W, about 50 W to about 200 W, or about 50 W to about 100 W.

[0187] In some implementations, the plasma exposure time is less than or equal to about 30 seconds, less than or equal to about 20 seconds, less than or equal to about 15 seconds, less than or equal to about 10 seconds, less than or equal to about 5 seconds, or less than or equal to about 2 seconds.

[0188] In some embodiments, the plasma is capacitively coupled plasma (CCP). In some embodiments, the plasma is inductively coupled plasma (ICP). In some embodiments, the plasma is a direct plasma generated within the treatment environment. In some embodiments, the plasma is a remote plasma generated outside the treatment environment.

[0189] In some embodiments, a plasma pulse is introduced into the ALD deposition cycle described above. In some embodiments, the plasma pulse replaces the hydrogen pulse in the ALD deposition cycle described above.

[0190] In some embodiments, a plasma pulse is introduced into the CVD deposition cycle. In some embodiments, the plasma pulse replaces hydrogen exposure in the CVD deposition cycle.

[0191] Figure 11This illustration depicts a process for seamless gap filling according to one or more embodiments of the present disclosure. The illustrated substrate 1100 has at least one feature 1105, which has a first metal 1110 at a bottom 1106 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 located outside the feature 1105 and one or more sidewall surfaces 1122 located within the feature 1105.

[0192] In some embodiments, substrate 1100 is exposed to optional cleaning processes. The cleaning process cleans the first metal surface 1111 at the bottom 1106 of feature 1105. In some embodiments, the cleaning process removes oxides from the first metal surface 1111. Cleaning processes in some embodiments include: degassing the substrate using hydrogen or without hydrogen, argon sputtering using hydrogen or without hydrogen, steam cleaning, or APC cleaning.

[0193] 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 1131 of the metal film is lower than the top surface 1121 of the dielectric 1120.

[0194] Optionally, a barrier layer 1140 may be formed on the top surface 1131 of the metal film 1130. The barrier layer 1140 may be any suitable material known to those skilled in the art that can prevent the deposition of padding material on the top surface 1131 of the metal film 1130. In some embodiments, the barrier layer 1140 comprises a self-assembled monolayer (SAM).

[0195] In some embodiments, a conformal pad 1150 is formed on the dielectric sidewalls 1122 and top surface 1121 of the dielectric 1120. In some embodiments, substantially no conformal pad 1150 is formed on the top surface 1131 of the metal film 1130 or on the optional barrier layer 1140. As used in this manner, the term "substantially none" means that less than or equal to about 10%, 5%, 2%, or 1% of the surface area of ​​the metal film 1130 or the optional barrier layer 1140 has deposited pad material. This does not include the edges of the sidewalls where the sidewalls intersect the top surface of the metal film or the optional barrier layer. In some embodiments, the conformal pad 1150 has less than or equal to about or The thickness of the conformal pad 1150. In some embodiments, the conformal pad 1150 has a thickness sufficient to form a continuous film. In some embodiments, the conformal pad 1150 comprises titanium nitride (TiN) and / or tantalum nitride (TaN).

[0196] In some embodiments, the barrier layer 1140 may optionally be removed from the top surface 1131 of the metal film 1130. The barrier layer 1140 may be removed by any suitable technique known to those skilled in the art.

[0197] In some embodiments, the metal film 1130 is used to fill the feature 1105 to form an overburden 1133 covering the conformal pad 1150 on the sidewalls of the dielectric and the top surface of the dielectric.

[0198] In some embodiments, the metal film 1130 may be optionally annealed to alter certain properties of the film and form an annealed metal film 1160. For example, in some embodiments, the metal film 1130 is annealed to increase the film density. Annealing can be performed under any suitable conditions using any suitable techniques known to those skilled in the art.

[0199] In some embodiments, a portion of the annealed metal film 1160 (or, if not annealed, a portion of the metal film 1130) is removed using any suitable technique. In some embodiments, a portion of the annealed metal film 1160 (or a portion of the metal film 1130) and at least some conformal pads 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 a portion of the metal film 1130) and a portion of the dielectric 1120, as well as at least some conformal pads 1150, are removed. In some embodiments, all conformal pads 1150 are removed. In some embodiments, chemical mechanical planarization is provided to remove the portions of the annealed metal film 1160 (or metal film 1130), conformal pads 1150, and dielectric 1120.

[0200] In some embodiments, one or more of a barrier layer 1140 or a conformal pad 1150 are deposited prior to the formation of the metal film 1130, such that the barrier layer 1140 is formed directly on the first metal 1110. In some embodiments, the barrier layer 1140 is removed from the surface of the first metal 1110 prior to the deposition of the metal film 1130. In some such embodiments, the metal film 1130 is deposited using an initial ALD process, followed by CECVD processing to grow the metal film.

[0201] In some embodiments, a combination of atomic layer deposition (ALD) and catalyst-enhanced chemical vapor deposition (CECVD) is used. The ALD portion of some embodiments follows this sequence: immersion in a metal precursor (e.g., ruthenium precursor), cleanup, immersion in a catalyst precursor (e.g., iodine precursor), and cleanup. According to some embodiments, individual exposures during the ALD portion have short durations. In some embodiments, the immersion portion is performed for less than 10 seconds, 5 seconds, 4 seconds, 3 seconds, or 2 seconds. In some embodiments, the metal precursor immersion is longer than the catalyst precursor immersion. In some embodiments, the cleanup portion is performed for less than 5 seconds, 4 seconds, 3 seconds, 2 seconds, or 1 second. Processed CECVD portions, whether or not connected to the ALD segment, typically have longer pulse times and different pulse sequences. The CECVD sequence of some embodiments includes: catalyst precursor immersion, followed by metal precursor immersion, and then cleanup. In some CECVD embodiments, catalyst precursor immersion has a duration ranging from 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, metal precursor immersion has a duration ranging from 20 to 1200 seconds, 30 to 800 seconds, 40 to 600 seconds, 50 to 450 seconds, or 60 to 300 seconds. In some embodiments, catalyst immersion has a shorter duration than metal immersion. In some embodiments, purging has a duration ranging from 1 to 100 seconds, 2 to 80 seconds, 3 to 60 seconds, 4 to 30 seconds, or 5 to 10 seconds.

[0202] In some embodiments, the processing includes an initial ALD-type process to build up the thickness of the second metal. Once a predetermined thickness of the second metal has been formed, the CECVD process is repeated to grow a film with the predetermined thickness. In some embodiments, the CECVD process is ineffective for second metal growth without an initial layer of metal deposited by selective ALD processing. In some embodiments, the ALD-type sequence deposits the second metal at a faster rate than the CECVD process. In some embodiments, after the metal film 1130 has been formed to a predetermined thickness (e.g., to the top of a feature), the processing sequence switches to an ALD-type sequence. The metal film can then be further processed as described herein.

[0203] Throughout this specification, references to "one embodiment," "some embodiments," "one or more embodiments," or "an embodiment" mean that a specific feature, structure, material, or characteristic described in connection with that embodiment is included in at least one embodiment of this disclosure. Therefore, phrases appearing in multiple places throughout this specification, such as "in one or more embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," do not necessarily refer to the same embodiment of this disclosure. Furthermore, in one or more embodiments, specific features, structures, materials, or characteristics may be combined in any manner.

[0204] While the disclosure herein has been described with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of this disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of this disclosure without departing from the spirit and scope of this disclosure. Therefore, this disclosure is intended to include modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. A method of forming a seamless gap fill, the method comprising the steps of: depositing a second metal film in a feature on a substrate to partially fill the feature with the second metal film, the feature comprising 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 in the feature, the at least one dielectric sidewall having a top surface outside the feature and one or more dielectric sidewall surfaces located in the feature, the second metal film comprising a second metal material, the second metal film being formed directly and selectively on the first metal surface relative to the one or more dielectric sidewall surfaces located in the feature, and the second metal film having a top surface lower than the top surface of the at least one dielectric sidewall; depositing a liner on the one or more dielectric sidewall surfaces located in the feature over the second metal film; filling the feature with the second metal material to cover the liner and the top surface of the at least one dielectric sidewall; and removing the second metal film and at least some of the liner from the top surface of the at least one dielectric sidewall and removing at least some of the dielectric to form a seamless gap fill.

2. The method of claim 1, further comprising the step of forming a barrier layer on the top surface of the second metal film prior to depositing the liner, the barrier layer preventing the liner from being formed on the top surface of the second metal film.

3. The method of claim 2, further comprising the step of removing the barrier layer from the top surface of the second metal film after forming the liner and prior to filling the feature with the second metal material.

4. The method of claim 1, further comprising the step of annealing the second metal film after filling the feature with the second metal material and prior to removing the second metal material from the top surface of the at least one dielectric sidewall.

5. The method of claim 1, wherein the first metal material comprises one or more of cobalt, tungsten, ruthenium, or molybdenum, and the second metal material comprises one or more of tungsten, ruthenium, or molybdenum.

6. A method of forming a seamless gap fill, the method comprising the steps of: (a) cleaning a bottom of a feature in a substrate, the feature comprising a bottom and at least one dielectric sidewall, the bottom comprising a first metal, the first metal having a first metal surface exposed in the feature, the at least one dielectric sidewall having a top surface outside the feature and one or more dielectric sidewall surfaces located in the feature; (b) depositing a ruthenium film directly on the first metal surface in the feature selectively relative to the one or more dielectric sidewall surfaces located in the feature, the ruthenium film partially filling the feature such that a top surface of the ruthenium film is lower than the top surface of the at least one dielectric sidewall; ​ (c) selectively forming a barrier 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 not substantially formed on the top surface of the ruthenium film; (e) removing the barrier layer from the top surface of the ruthenium film; (f) filling the features with ruthenium to cover the conformal liner on the one or more dielectric sidewall surfaces and the top surface of the at least one dielectric sidewall; (g) annealing the ruthenium film; and (h) removing the ruthenium film and a portion of the dielectric and removing at least some of the liner to form a ruthenium seamless gap fill. ​

Images