Dual plasma pre-clean for selective gap fill

Abstract

Methods for pre-cleaning a substrate having metal and dielectric surfaces are described. A substrate including a surface structure having a metal bottom, a dielectric sidewall, and a field of dielectric is exposed to a dual plasma process in a processing chamber to remove chemical residues and / or impurities from the metal bottom, the dielectric sidewall, and / or the field of dielectric, and / or to repair surface defects in the dielectric sidewall and / or the field of dielectric. The dual plasma process includes a direct plasma and a remote plasma.

Description

Technical Field

[0001] Embodiments of this disclosure generally relate to methods for filling gaps in semiconductors. Specifically, embodiments of this disclosure relate to methods for pre-cleaning substrates to improve metal deposition selectivity. Background Technology

[0002] Internal interconnect metallization is widely used in logic and memory devices. Typically, a substrate is used in via / trench gap filling applications, followed by a high-volume deposited CVD / PVD film. However, as feature sizes decrease, via / trench structures become smaller and the volume ratio of the substrate increases, making it difficult to achieve defect-free and low-resistivity metal gap filling.

[0003] Selective deposition processes utilize the temperature difference between one surface material and another during deposition. This temperature delay can act as a lever to enable bottom-up gap filling without seams / voids and liner. However, several challenges hinder the widespread adoption of this technique. For example, impurities at the bottom of vias and on dielectric surfaces can reduce the selectivity of selective metal growth on metal surfaces relative to the dielectric field. Current processes employing different direct plasma treatments (e.g., H2 and O2 plasmas) to clean surface contaminants (e.g., oxygen, carbon, fluorine, chlorine) typically involve a trade-off between cleaning efficiency and selectivity: plasma-induced damage reduces selectivity during subsequent depositions once impurities and metal oxides are completely removed.

[0004] Effectively cleaning metal surfaces while maintaining minimal or no on-field growth is typically a major challenge preventing widespread use. Similarly, different surface structures with varying etching residues or contaminants may require different pre-cleaning treatments to enable selective growth.

[0005] Accordingly, there is a ongoing need in the art for improved methods and apparatus for pre-cleaning substrate surfaces for selective deposition. Summary of the Invention

[0006] One or more embodiments of this disclosure relate to a pre-cleaning method. A substrate comprising a surface structure having a metal bottom, dielectric sidewalls, and a dielectric field is exposed to a dual-plasma treatment in a processing chamber to remove chemical residues and / or impurities from the metal bottom, the dielectric sidewalls, and / or the dielectric field, and / or repair surface defects in the dielectric sidewalls and / or the dielectric field. The dual-plasma treatment includes direct plasma and remote plasma.

[0007] Additional embodiments of this disclosure relate to a pre-cleaning method. A substrate comprising a surface structure having a field with a metal bottom, dielectric sidewalls, and a dielectric is exposed to a dual-plasma treatment within a processing chamber including a dual-plasma cover to remove chemical residues and / or impurities from the field of the metal bottom, the dielectric sidewalls, and / or the dielectric, and / or repair surface defects in the field of the dielectric sidewalls and / or the dielectric. This dual-plasma treatment includes direct plasma and remote plasma.

[0008] Further embodiments of this disclosure relate to a non-transitory computer-readable medium comprising instructions to cause the processing chamber, when executed by a controller of the processing chamber, to perform the following operations: exposing a substrate with a surface structure comprising a field having a metal bottom, dielectric sidewalls, and a dielectric field within the processing chamber to a dual plasma process to remove chemical residues and / or impurities from the field of the metal bottom, the dielectric sidewalls, and / or the dielectric, and / or repair surface defects in the field of the dielectric sidewalls and / or the dielectric; wherein the dual plasma process comprises direct plasma and remote plasma. Attached Figure Description

[0009] Therefore, in order to understand the above-described features of this disclosure in detail, the disclosure can be described in more detail by referring to embodiments (briefly summarized above), some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings illustrate only typical embodiments of the disclosure and should therefore not be considered as limiting its scope, as other equivalent embodiments are permissible.

[0010] Figure 1 A schematic diagram showing a substrate structure according to one or more embodiments of the present disclosure is provided.

[0011] Figure 2 The illustration shows a flowchart of a method according to one or more embodiments of the present disclosure;

[0012] Figure 3 The illustration shows a schematic diagram of a processing tool according to one or more embodiments of the present disclosure; and

[0013] Figure 4 The illustration shows a schematic diagram of a processing tool according to one or more embodiments of the present disclosure. Detailed Implementation

[0014] 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 steps set forth in the following description. This disclosure can have other embodiments and can be implemented or carried out in various ways.

[0015] As used in this specification and the appended claims, the term "substrate" refers to a surface or a portion thereof on which a treatment is performed. Those skilled in the art will also understand that, unless the context clearly indicates otherwise, reference to substrate may also refer only to a portion of the substrate. Furthermore, reference to deposition on a substrate may mean both a bare substrate and a substrate on which one or more films or features are deposited or formed.

[0016] As used herein, “substrate” means any substrate or material surface formed on a substrate on which a film treatment is performed during manufacturing processes. For example, substrate surfaces on which treatments can be performed include materials such as silicon, silicon oxide, strained silicon, silicon-on-insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, glass, sapphire, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials, depending on the application. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes such as polishing, etching, reduction, oxidation, hydroxylation, annealing, UV curing, electron beam curing, and / or baking of the substrate surface. In addition to performing film treatments directly on the surface of the substrate itself, any of the disclosed film treatment steps may also be performed on an underlayer formed on the substrate, as disclosed in more detail below, and the term “substrate surface” is intended to include the underlayer as indicated by the context. Thus, for example, where a film / layer or a portion of a film / layer has already been deposited on the substrate surface, the exposed surface of a newly deposited film / layer becomes the substrate surface.

[0017] One or more embodiments of this disclosure advantageously provide a method for pre-cleaning substrates for a wider range of structural types and selective windows. Some embodiments advantageously provide a dual-plasma process with direct and remote plasma, simultaneously satisfying pre-cleaning efficiency and selectivity. The cleaning process described herein advantageously removes residues / impurities from both dielectric and metal surfaces from previous treatments. Furthermore, metal oxides from the previously treated metal surfaces are reduced to pure metal. Subsequently, good metal deposition performance is achieved, such as low line resistance, good yield, and high reliability. In one or more embodiments, the selectivity of tungsten (W) deposition is improved after a dual-plasma process combining direct and remote plasma with hydrogen (H2), oxygen (O2), and other gases. In one or more embodiments, a dual-plasma cap capable of simultaneously performing direct and remote plasma is part of the processing chamber.

[0018] Some embodiments of this disclosure provide methods for selective metal deposition at the bottom of contacts or vias, methods that require clean surfaces and begin with minimal incubation. In some embodiments, chemical residues and / or impurities that could hinder selective deposition and cause significant incubation delays are removed, including but not limited to: metal oxides / metal nitrides / metal carbides, etc. Some embodiments effectively clean metal contaminants while maintaining a contact / via structure preferred for selective processing.

[0019] The processing described in this disclosure utilizes a dual-plasma process that combines direct and remote plasma with hydrogen (H2), oxygen (O2), and other gases. The use of a dual-plasma cap advantageously separates ions and free radicals.

[0020] During processing, the substrate is exposed to plasma treatment to remove chemical residues and / or impurities from the metal bottom, dielectric sidewalls, and / or dielectric fields, and / or repair surface defects in the dielectric sidewalls and / or dielectric fields. Dual plasma treatment includes one plasma as a direct plasma and another plasma as a remote plasma. In one or more embodiments, the plasma includes hydrogen plasma and oxygen plasma. In one or more embodiments, the plasmas may be supplied sequentially. In other embodiments, the plasmas are supplied simultaneously.

[0021] In one or more embodiments, the substrate is exposed to a dual plasma process for treatment or cleaning. In one or more embodiments, the substrate includes at least one feature. The at least one feature may include any feature known to those skilled in the art, including but not limited to trenches, vias, or peaks. In embodiments where the substrate is exposed to remote plasma and / or direct plasma for treatment or cleaning, the treatment or cleaning removes, for example, one or more of residues and / or native oxides from a previous treatment.

[0022] Experiments show that selective tungsten (W) deposition exhibits a lower selective loss defect number after cleaning the substrate with H2, O2, and other gases using both direct and remote plasma. The experiments also show reduced growth of the structural field and sidewalls (caused by selective loss), achieving bottom-up growth. Uniform and mild internal structural treatment was also achieved, with similar treatments achieved on the field and sidewalls / bottom.

[0023] Figure 1 The diagram illustrates a contact structure used according to one or more embodiments. Figure 1The substrate 100 illustrated includes a structure 130 defined by a first material 102 and a second material 104. In the illustrated embodiment, the structure 130, including a bottom 132 and a side 134, is a through-hole or trench. The structure is defined on the bottom 132 by the first material 102 and on the side 134 by a second material 104 different from the first material 102. In some embodiments, the first material 102 includes a metal 110, which forms a metallic bottom 115 of the structure. The metal 110 can be any suitable metal, including but not limited to tungsten (W), cobalt (Co), and / or ruthenium (Ru). In some embodiments, the first material 102 and the bottom 132 of the structure 130 include nonmetals. Suitable nonmetals include, but are not limited to, metal nitrides (e.g., titanium nitride (TiN)), metal silicides (e.g., titanium silicide (TiSi)), or silicon (Si). As used in this specification and the appended claims, unless otherwise specified by subscripts, chemical formulas represent elemental identity and are not intended to imply any particular stoichiometry. For example, titanium nitride (TiN) films can have any suitable combination of titanium and nitrogen atoms, and are not limited to a single relationship.

[0024] In some embodiments, the second material 104 includes a dielectric 120. The sidewalls 134 of the structure 130 are formed by the sidewalls 122 of the dielectric 120. The top surface 106 of the second material 104 is also referred to as a field. In some embodiments, the second material 104 includes a dielectric 120 having sidewalls 122 and a field 124. The dielectric 120 can be any suitable material, including but not limited to silicon oxide (SiO), silicon dioxide (SiO2), silicon nitride (SiN), silicon oxynitride (SiON), aluminum nitride (AlN), aluminum oxide (AlO), or high-k dielectric materials. In some embodiments, the second material 104 includes a hard mask material (e.g., carbon (C)).

[0025] Figure 2 The illustration depicts a method 150 for pre-cleaning a substrate prior to selective deposition, according to one or more embodiments. Surface contaminants in some embodiments include one or more of the following: oxygen, nitrogen, carbon, or halogens (e.g., fluorine, chlorine, bromine, or iodine). In some embodiments, contaminants include organic compounds.

[0026] At operation 152, the substrate may optionally be placed into the processing chamber. At operation 154, the substrate is exposed to direct plasma. At operation 156, the substrate is exposed to remote plasma.

[0027] In one or more embodiments, the dual plasma processing includes exposing the substrate to direct plasma and then sequentially exposing it to remote plasma.

[0028] In an exemplary non-limiting embodiment, the cleaning process sequence includes: (1) performing a direct plasma treatment on the substrate in a processing chamber, wherein the plasma comprises hydrogen; and (2) performing a remote plasma treatment on the substrate in a processing chamber, wherein the plasma comprises oxygen. In one embodiment, after (1) and before (2), the cleaning process sequence further includes performing a direct plasma treatment on the substrate in a processing chamber, wherein the plasma comprises oxygen. In one embodiment, after (2), the cleaning process sequence further includes performing a remote plasma treatment on the substrate in a processing chamber, wherein the plasma comprises hydrogen. In one embodiment, after (2), the cleaning process sequence further includes performing a direct plasma treatment on the substrate in a processing chamber, wherein the plasma comprises hydrogen, and then performing a remote plasma treatment on the substrate in a processing chamber, wherein the plasma comprises hydrogen.

[0029] In another exemplary non-limiting embodiment, the cleaning process sequence includes performing the following plasma treatments: (1) direct hydrogen plasma; (2) direct oxygen plasma treatment; (3) remote oxygen plasma; and (4) remote hydrogen plasma. Optionally, direct hydrogen plasma is provided between (3) and (4).

[0030] In an exemplary, non-limiting embodiment, the cleaning process sequence includes: (1) performing direct plasma treatment on the substrate in a processing chamber, wherein the plasma comprises hydrogen; and (2) performing remote plasma treatment on the substrate in a processing chamber, wherein the plasma comprises hydrogen. Other embodiments may include a cleaning process sequence after (1) and before (2), further comprising one or more of the following: direct oxygen plasma; remote oxygen plasma; direct hydrogen plasma; and remote hydrogen plasma. In one embodiment, after (2), the cleaning process sequence further comprises one or more of the following: direct oxygen plasma; remote oxygen plasma; direct hydrogen plasma; and remote hydrogen plasma.

[0031] In an exemplary, non-limiting embodiment, the cleaning process sequence includes: (1) performing direct plasma treatment on the substrate in a processing chamber, wherein the plasma comprises oxygen; and (2) performing remote plasma treatment on the substrate in a processing chamber, wherein the plasma comprises oxygen. Other embodiments may include a cleaning process sequence after (1) and before (2), further including one or more of the following: direct oxygen plasma; remote oxygen plasma; direct hydrogen plasma; and remote hydrogen plasma. In one embodiment, after (2), the cleaning process sequence further includes one or more of the following: direct oxygen plasma; remote oxygen plasma; direct hydrogen plasma; and remote hydrogen plasma.

[0032] In another exemplary non-limiting embodiment, the cleaning process includes performing the following plasma treatments: (1) co-current direct plasma of hydrogen and oxygen; and (2) co-current remote plasma of hydrogen and oxygen.

[0033] In some embodiments, the hydrogen (H2) plasma is a capacitively coupled plasma (CCP). In some embodiments, the H2 plasma is a low-energy plasma.

[0034] In one or more embodiments, the hydrogen plasma has a pressure in the range of 1 Torr to 30 Torr.

[0035] In some embodiments, the oxygen plasma is a capacitively coupled plasma (CCP). In some embodiments, the oxygen (O2) plasma is a high-density, high-energy plasma. In some embodiments, the low-energy plasma has a power of greater than or equal to 100 watts to less than or equal to 600 watts.

[0036] In one or more embodiments, the substrate is maintained at a temperature ranging from -20°C to 500°C during exposure to oxygen plasma.

[0037] In some embodiments, the oxygen plasma has a pressure in the range of 1 Torr to 30 Torr.

[0038] Following operation 156, the substrate may be further processed for selective metal deposition. In one or more embodiments, after cleaning, the substrate is exposed to at least one precursor of a metal to selectively form a metal film on the substrate. In one or more embodiments, the method further includes exposing the substrate to at least one precursor relative to a plasma-enhanced chemical vapor deposition (PECVD) process or a plasma-enhanced atomic layer deposition (PEALD) process to deposit a film on the substrate. Any suitable precursor known to those skilled in the art can be used to form a film on the substrate.

[0039] In some implementations... Figure 2 The pre-cleaning method illustrated in the figure effectively removes residues and enhances the selectivity of subsequent deposition treatments.

[0040] Various hardware arrangements can be used to implement method 200. In some embodiments, one or two chambers can be used to achieve multiple processes for surface cleaning. Chambers can be used for O2 / Ar / H2 plasma processes with different gas types. In some embodiments, H2 and O2 processes are performed in one chamber.

[0041] Figure 3A processing tool 200 according to one or more embodiments is illustrated. In one or more embodiments, the processing tool 200 includes a processing chamber 201. The processing chamber includes a cover 202 and at least one sidewall 204. In one or more embodiments, the cover 202 and at least one sidewall 204 define an internal space 205 of the processing chamber 201. In one or more embodiments, the processing tool 200 includes a remote plasma unit 206 within the internal space 205 of the processing chamber 201. In one or more embodiments, a direct plasma unit 208 is located within the internal space 205 of the processing chamber 201. In one or more embodiments, one of the remote plasma units 206 generates remote plasma, while the direct plasma unit 208 generates direct plasma. In one or more embodiments, the generation of remote plasma and the generation of direct plasma occur sequentially. In some embodiments, the generation of remote plasma occurs first, followed by the generation of direct plasma. In other embodiments, the generation of direct plasma occurs first, followed by the generation of remote plasma. In one or more embodiments, the generation of remote plasma and the generation of direct plasma occur simultaneously.

[0042] In one or more embodiments, ion filter 212 separates remote plasma unit 206 and direct plasma unit 208. In one or more embodiments, ion filter 212 is used to filter ions from the plasma effluent during transport from remote plasma unit 206 to substrate processing region 215. In one or more embodiments, ion filter 212 functions to reduce or eliminate ionicly charged matter traveling from remote plasma unit 206 to substrate 230. In one or more embodiments, uncharged neutral and free radical matter can pass through at least one aperture 218 in ion filter 212 to react at substrate 230. It should be noted that completely eliminating ionicly charged matter in the reaction region 215 surrounding substrate 230 is not always a desirable goal. In one or more embodiments, ionic matter is required to reach substrate 230 for etching and / or deposition processes. In these cases, ion filter 212 helps to control the concentration of ionic matter in reaction region 215 at levels that aid in processing / cleaning and / or deposition.

[0043] In one or more embodiments, the processing tool includes at least one electrode within a processing chamber. In one or more embodiments, the at least one electrode is located within the internal space 205 of the processing chamber 201. Figure 3 In the embodiment illustrated herein, at least one electrode 210 is positioned in electrical communication with a remote plasma unit 206.

[0044] In one or more embodiments, the processing chamber 201 includes a base 214. In one or more embodiments, the base 214 is configured to support a semiconductor substrate 230 in a processing region 215. In one or more embodiments, the base 214 may have a heat exchange passage (not shown) through which a heat exchange fluid flows to control the temperature of the substrate 230. In one or more embodiments, the temperature of the substrate 230 may be cooled or heated to maintain a relatively low temperature, for example, from about -20°C to about 400°C. In one or more embodiments, the heat exchange fluid includes one or more of ethylene glycol or water. In other embodiments, the base 214 is resistively heated using an embedded resistance heater element (not shown) to achieve a relatively high temperature, for example, from about 100°C to about 1100°C, or from about 200°C to about 750°C. In one or more embodiments, the base 214 is configured to rotate. In one or more embodiments, the base 214 includes electrodes 216 within its interior, and the base 214 is powered by the RF generator 250 and matched by the RF matcher 240. In one or more embodiments, the base 214 comprises a metallic material and is itself an electrode.

[0045] In one or more embodiments, at least one power source (e.g., RF generator 250) is electrically connected to the processing chamber 201 via a first RF matcher 240 and a second RF matcher 245.

[0046] In one or more embodiments, two RF generators 250 are electrically connected to the processing chamber 201. In such an embodiment, a first RF generator 250 is electrically connected to a base electrode 216, and a second RF generator 255 is electrically connected to a top electrode 210.

[0047] In one or more embodiments, a radio frequency (RF) powered remote plasma unit 206 and / or a direct plasma unit 208 are used to generate plasma. In one or more embodiments, alternating current (AC) is rectified and switched to supply current to an RF amplifier. The RF amplifier operates at a reference frequency (e.g., 13.56 MHz), driving current through an output matching network, then through a power measurement circuit to the power supply output. The output matching network is typically designed to connect a generator optimized to drive a specific impedance (e.g., 50 ohms) to have the same characteristic impedance as coaxial cables commonly used in industry. Power flows through a matched cable section, is measured by a matching controller, and is converted via load matching. Load matching is typically an electrically operated autotuner, thus introducing a predetermined time delay before the system is properly configured. After load matching, the power is then directed to a plasma excitation circuit that drives two electrodes in a evacuated processing chamber. Process gas is introduced into the evacuated processing chamber and, when driven by the circuit, generates plasma. Because the matching network or load matching is electrically powered, the response time from the matching network is typically on the order of one second or longer.

[0048] In some embodiments, the plasma power ranges from about 10 W to about 1000 W, including from about 200 W to about 600 W. In some embodiments, the plasma power is less than or equal to about 1000 W, or less than or equal to about 6500 W.

[0049] The plasma frequency can be any suitable frequency. In some embodiments, the plasma has a frequency in the range of about 200 kHz to 30 MHz. In some embodiments, the plasma frequency is less than or equal to about 20 MHz, less than or equal to about 10 MHz, less than or equal to about 5 MHz, less than or equal to about 1000 kHz, or less than or equal to about 500 kHz. In some embodiments, the plasma frequency is greater than or equal to about 210 kHz, greater than or equal to about 250 kHz, greater than or equal to about 600 kHz, greater than or equal to about 750 MHz, greater than or equal to about 1200 kHz, greater than or equal to about 2 MHz, greater than or equal to about 4 MHz, greater than or equal to about 7 MHz, greater than or equal to about 12 MHz, greater than or equal to about 15 MHz, or greater than or equal to about 25 MHz. In one or more embodiments, the plasma has a frequency of about 13.56 MHz, or about 350 kHz, or about 400 kHz, or about 27 MHz, or about 40 MHz, or about 60 MHz.

[0050] In one or more embodiments, controller 220 may be provided and coupled to various components of processing tool 200 to control its operation. Controller 220 may be a single controller controlling the entire processing tool 200, or multiple controllers controlling various parts of processing tool 200. For example, processing tool 200 may include separate controllers for each of processing chamber 202, remote plasma unit 206, direct plasma unit 208, and power source 250.

[0051] In some embodiments, the processing chamber 201 further includes a controller 220. In one or more embodiments, the controller 220 controls the ignition of the plasma by a remote plasma unit 206 and / or a direct plasma unit 208 within the processing chamber 201.

[0052] In some implementations, controller 220 includes a central processing unit (CPU) 222, memory 224, input / output (I / O) 226, and support circuitry 228. Controller 220 may control processing tool 200 directly or via a computer (or controller) associated with a particular processing chamber and / or support system components.

[0053] Controller 220 may be one of any form of general-purpose computer processor that can be used in an industrial environment to control various chambers and subprocessors. The memory 224 or computer-readable medium of controller 220 may be one or more readily available memories, such as non-transitory memory (e.g., random access memory (RAM)), read-only memory (ROM), floppy disk, hard disk, optical storage media (e.g., optical disc or digital video disc), flash drive, or any other form of local or remote digital storage. Memory 224 may hold a set of instructions operable by the processor (CPU 222) to control parameters and components of processing tool 200.

[0054] Support circuitry 228 is coupled to CPU 222 for conventional processor support. This circuitry includes cache, power supply, clock circuitry, input / output circuitry systems, and subsystems. One or more processes may be stored as software routines in memory 224, which, when executed or invoked by the processor, enable the processor to control the operation of processing tool 200 or individual processing units (e.g., remote plasma unit 206 and direct plasma unit 208) in the manner described herein. Software routines may also be stored and / or executed by a hardware-remotely located second CPU (not shown) controlled by CPU 222.

[0055] Some or all of the processes and methods of this disclosure may also be executed in hardware. Thus, the processes can be implemented in software and executed using a computer system in hardware (e.g., application-specific integrated circuits or other types of hardware) or in a combination of software and hardware. When executed by a processor, the software routines transform a general-purpose computer into a dedicated computer (controller) that controls the operation of the control chamber to perform the processes.

[0056] In some embodiments, controller 220 has one or more configurations to perform individual processes or subprocesses to perform the method. Controller 220 may be connected to and configured to operate intermediate components to perform the functions of the method. For example, controller 220 may be connected to and configured to control one or more of the remote plasma unit 206, direct plasma unit 208, base 214, at least one electrode, or other components.

[0057] Figure 4 A processing tool 300 according to one or more embodiments is illustrated. In one or more embodiments, the processing tool 300 includes a processing chamber 301. The processing chamber includes a cover 302 and at least one sidewall 304. In one or more embodiments, the cover 302 and at least one sidewall 304 define an internal space 305 of the processing chamber 301. In one or more embodiments, the processing tool 300 includes a remote plasma unit 306 within the internal space 305 of the processing chamber 301. In one or more embodiments, a direct plasma unit 308 is located within the internal space 305 of the processing chamber 301. In one or more embodiments, one of the remote plasma units 306 generates remote plasma, while the direct plasma unit 308 generates direct plasma. In one or more embodiments, the generation of remote plasma and the generation of direct plasma occur sequentially. In some embodiments, the generation of remote plasma occurs first, followed by the generation of direct plasma. In other embodiments, the generation of direct plasma occurs first, followed by the generation of remote plasma. In one or more embodiments, the generation of remote plasma and the generation of direct plasma occur simultaneously.

[0058] In one or more embodiments, an ion filter 312 separates the remote plasma unit 306 and the direct plasma unit 308. In one or more embodiments, the ion filter 312 is used to filter ions from the plasma effluent during transport from the remote plasma unit 306 to the substrate processing region 315. In one or more embodiments, the ion filter 312 functions to reduce or eliminate ionicly charged matter traveling from the remote plasma unit 306 to the substrate 330. In one or more embodiments, uncharged neutral and free radical matter can pass through at least one aperture 318 in the ion filter 312 to react at the substrate 330. It should be noted that completely eliminating ionicly charged matter in the reaction region 315 surrounding the substrate 330 is not always the desired goal. In one or more embodiments, ionic matter is required to reach the substrate 330 for etching and / or deposition processes. In these cases, the ion filter 312 helps to control the concentration of ionic matter in the reaction region 315 at levels that aid in the processing / cleaning and / or deposition processes.

[0059] In one or more embodiments, the ion filter 312 includes a nozzle.

[0060] In one or more embodiments, the processing tool includes at least one electrode within a processing chamber. In one or more embodiments, the at least one electrode is located within an internal space 305 of the processing chamber 301. Figure 4 In the embodiment illustrated herein, at least one electrode 316 is positioned in electrical communication with the base 314.

[0061] In one or more embodiments, the processing chamber 301 includes a base 314. In one or more embodiments, the base 314 is configured to support a semiconductor substrate 330 in a processing region 315. In one or more embodiments, the base 314 may have a heat exchange channel (not shown) through which a heat exchange fluid flows to control the temperature of the substrate 330. In one or more embodiments, the temperature of the substrate 330 may be cooled or heated to maintain a relatively low temperature, for example, from about -20°C to about 400°C, or from about 0°C to about 400°C. In one or more embodiments, the heat exchange fluid includes one or more of ethylene glycol or water. In other embodiments, the base 314 is resistively heated by using an embedded resistance heater element (not shown) to achieve a relatively high temperature, for example, from about 100°C to about 1100°C, or from about 200°C to about 750°C. In one or more embodiments, the base 314 is configured to rotate. In one or more embodiments, the base 314 includes electrodes 316 within its interior, and the base 314 is powered by an RF generator 350 and matched by an RF matcher 340. In one or more embodiments, the base 314 comprises a metallic material and is itself an electrode.

[0062] In one or more embodiments, at least one power source (e.g., RF generator 350) is electrically connected to the processing chamber 301 via an RF matcher 340.

[0063] In one or more embodiments, two RF generators are electrically connected to the processing chamber 301. In such an embodiment, a first RF generator 350 is electrically connected to a base electrode 316, and a second RF generator 355 is electrically connected to an inductively coupled plasma (ICP) coil 370.

[0064] In one or more embodiments, a radio frequency (RF) powered remote plasma unit 306 and / or a direct plasma unit 308 are used to generate plasma. In one or more embodiments, alternating current (AC) is rectified and switched to supply current to an RF amplifier. The RF amplifier operates at a reference frequency (e.g., 13.56 MHz), driving current through an output matching network, then through a power measurement circuit to the power supply output. The output matching network is typically designed to connect a generator optimized to drive a specific impedance (e.g., 50 ohms) to have the same characteristic impedance as coaxial cables commonly used in industry. Power flows through a matched cable section, is measured by a matching controller, and is converted via load matching. Load matching is typically an electrically operated autotuner, thus introducing a predetermined time delay before the system is properly configured. After load matching, the power is then directed to a plasma excitation circuit that drives two electrodes in a evacuated processing chamber. Process gas is introduced into the evacuated processing chamber and, when driven by the circuit, generates plasma. Because the matching network or load matching is electrically powered, the response time from the matching network is typically on the order of one second or longer.

[0065] In some embodiments, the plasma power ranges from about 10 W to about 1000 W, including from about 200 W to about 600 W. In some embodiments, the plasma power is less than or equal to about 1000 W, or less than or equal to about 6500 W.

[0066] The plasma frequency can be any suitable frequency. In some embodiments, the plasma has a frequency in the range of about 200 kHz to 30 MHz. In some embodiments, the plasma frequency is less than or equal to about 20 MHz, less than or equal to about 10 MHz, less than or equal to about 5 MHz, less than or equal to about 1000 kHz, or less than or equal to about 500 kHz. In some embodiments, the plasma frequency is greater than or equal to about 210 kHz, greater than or equal to about 250 kHz, greater than or equal to about 600 kHz, greater than or equal to about 750 MHz, greater than or equal to about 1200 kHz, greater than or equal to about 2 MHz, greater than or equal to about 4 MHz, greater than or equal to about 7 MHz, greater than or equal to about 12 MHz, greater than or equal to about 15 MHz, or greater than or equal to about 25 MHz. In one or more embodiments, the plasma has a frequency of about 13.56 MHz, or about 350 kHz, or about 400 kHz, or about 27 MHz, or about 40 MHz, or about 60 MHz.

[0067] In one or more embodiments, a controller 320 may be provided and coupled to various components of the processing tool 300 to control its operation. The controller 320 may be a single controller controlling the entire processing tool 300, or multiple controllers controlling various parts of the processing tool 300. For example, the processing tool 300 may include separate controllers for each of the processing chamber 301, the remote plasma unit 306, the direct plasma unit 308, and the power source 350.

[0068] In some embodiments, the processing chamber 301 further includes a controller 320. In one or more embodiments, the controller 320 controls the ignition of the plasma by a remote plasma unit 306 and / or a direct plasma unit 308 within the processing chamber 301.

[0069] In some implementations, controller 320 includes a central processing unit (CPU) 322, memory 324, input / output (I / O) 326, and support circuitry 328. Controller 320 may control processing tool 300 directly or via a computer (or controller) associated with a particular processing chamber and / or support system components.

[0070] The controller 320 may be one of any form of general-purpose computer processor that can be used in an industrial environment to control various chambers and subprocessors. The memory 324 or computer-readable medium of the controller 320 may be one or more readily available memories, such as non-transitory memory (e.g., random access memory (RAM)), read-only memory (ROM), floppy disk, hard disk, optical storage media (e.g., optical disc or digital video disc), flash drive, or any other form of local or remote digital storage. The memory 324 may hold a set of instructions operable by the processor (CPU 322) to control parameters and components of the processing tool 300.

[0071] Support circuitry 328 is coupled to CPU 322 for conventional processor support. This circuitry includes cache, power supply, clock circuitry, input / output circuitry systems, and subsystems. One or more processes may be stored as software routines in memory 324, which, when executed or invoked by the processor, enable the processor to control the operation of processing tool 300 or individual processing units (e.g., remote plasma unit 306 and direct plasma unit 308) in the manner described herein. Software routines may also be stored and / or executed by a hardware-remotely located second CPU (not shown) controlled by CPU 322.

[0072] Some or all of the processes and methods of this disclosure may also be executed in hardware. Thus, the processes can be implemented in software and executed using a computer system in hardware (e.g., application-specific integrated circuits or other types of hardware) or in a combination of software and hardware. When executed by a processor, the software routines transform a general-purpose computer into a dedicated computer (controller) that controls the operation of the control chamber to perform the processes.

[0073] In some embodiments, controller 320 has one or more configurations to perform individual processes or subprocesses to perform the method. Controller 320 may be connected to and configured to operate intermediate components to perform the functions of the method. For example, controller 320 may be connected to and configured to control one or more of a remote plasma unit 306, a direct plasma unit 308, a base 314, at least one electrode 316, an ICP coil 370, or other components.

[0074] Additional embodiments of this disclosure relate to a processing system having one or more processing chambers. The processing chambers of this system include a cooled base. In one or more embodiments, the processing chambers include... Figure 3 or Figure 4 The processing tool for either of them.

[0075] One or more embodiments relate to a non-transitory computer-readable medium comprising instructions to cause a processing chamber, when executed by a controller of the processing chamber, to perform the following operations: exposing a substrate in the processing chamber to a dual plasma process comprising a surface structure having a metal bottom, dielectric sidewalls, and a field of dielectric to remove chemical residues and / or impurities from the metal bottom, the dielectric sidewalls, and / or the field of dielectric, and / or repair surface defects in the dielectric sidewalls and / or the field of dielectric; wherein the dual plasma process comprises direct plasma followed by remote plasma.

[0076] Throughout this specification, references to "one embodiment," "some embodiments," "one or more embodiments," or "an embodiment" refer to a specific feature, structure, material, or characteristic described in connection with that embodiment being included in at least one embodiment of this disclosure. Therefore, phrases appearing 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 suitable manner.

[0077] Although the disclosure herein has been described with reference to specific embodiments, those skilled in the art will understand that the described embodiments are merely illustrative of the principles and applications of the disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of this disclosure without departing from the spirit and scope of the disclosure. Therefore, the disclosure may include modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. A method for filling a gap in a semiconductor, the method comprising the steps of: exposing a substrate comprising a surface structure having a metal bottom, a dielectric sidewall, and a field of dielectric in a process chamber to a dual plasma process to remove chemical residues and / or impurities from the metal bottom, the dielectric sidewall, and / or the field of dielectric, and / or to repair surface defects in the dielectric sidewall and / or the field of dielectric; and exposing the substrate to a tungsten precursor to form a tungsten film on the substrate, the tungsten film formed on the metal bottom relative to the dielectric sidewall and the field of dielectric, wherein the dual plasma process comprises a direct plasma and a remote plasma, wherein the process chamber comprises at least one sidewall defining an interior space, the interior space comprising a remote plasma unit and a direct plasma unit.

2. The method of claim 1, wherein the direct plasma comprises a hydrogen plasma and the remote plasma comprises an oxygen plasma.

3. The method of claim 2, wherein the dual plasma process further comprises one or more of: a direct oxygen plasma, a remote oxygen plasma, a direct hydrogen plasma, and a remote hydrogen plasma.

4. The method of claim 1, wherein the direct plasma comprises an oxygen plasma and the remote plasma comprises a hydrogen plasma.

5. The method of claim 4, wherein the dual plasma process further comprises one or more of: a direct oxygen plasma, a remote oxygen plasma, a direct hydrogen plasma, and a remote hydrogen plasma.

6. The method of claim 1, wherein the direct plasma comprises an oxygen plasma and the remote plasma comprises an oxygen plasma.

7. The method of claim 6, wherein the dual plasma process further comprises one or more of: a direct oxygen plasma, a remote oxygen plasma, a direct hydrogen plasma, and a remote hydrogen plasma.

8. The method of claim 1, wherein the direct plasma comprises a hydrogen plasma and the remote plasma comprises a hydrogen plasma.

9. The method of claim 8, wherein the dual plasma process further comprises one or more of: a direct oxygen plasma, a remote oxygen plasma, a direct hydrogen plasma, and a remote hydrogen plasma.

10. The method of claim 1, wherein the dielectric comprises one or more of: silicon nitride (SiN), silicon oxide (SiO), silicon oxynitride (SiON), or a high-k dielectric.

11. The method of claim 1, wherein the metal comprises one or more of: tungsten (W), cobalt (Co), or ruthenium (Ru).

12. The method of claim 1, wherein the dielectric comprises silicon oxide (SiO), silicon nitride (SiN), and / or silicon oxynitride (SiON), and the metal comprises tungsten (W).

13. The method of claim 1, wherein the process chamber comprises a dual plasma lid.

14. The method of claim 1, wherein the substrate is exposed to direct hydrogen plasma prior to remote oxygen plasma.

15. The method of claim 1, wherein the substrate is exposed to direct oxygen plasma prior to remote hydrogen plasma.

16. A non-transitory computer readable medium comprising instructions to cause a processing chamber to perform the following operations when executed by a controller of the processing chamber: exposing a substrate comprising a surface structure having a metal bottom, a dielectric sidewall, and a field of dielectric in a processing chamber to a dual plasma process to remove chemical residue and / or impurities from the metal bottom, the dielectric sidewall, and / or the field of dielectric, and / or to repair surface defects in the dielectric sidewall and / or the field of dielectric; and exposing the substrate to a tungsten precursor to form a tungsten film on the substrate, the tungsten film formed on the metal bottom relative to the dielectric sidewall and the field of dielectric, wherein the dual plasma process comprises a direct plasma and a remote plasma, wherein the processing chamber comprises at least one sidewall defining an interior space, the interior space comprising a remote plasma unit and a direct plasma unit.

17. The non-transitory computer readable medium of claim 16, further comprising instructions to cause the processing chamber to perform the following operations when executed by a controller of the processing chamber: exposing the substrate to a direct oxygen plasma and a remote hydrogen plasma.

18. The non-transitory computer readable medium of claim 16, further comprising instructions to cause the processing chamber to perform the following operations when executed by a controller of the processing chamber: exposing the substrate to a direct oxygen plasma and a remote hydrogen plasma.

19. The non-transitory computer readable medium of claim 16, further comprising instructions to cause the processing chamber to perform the following operations when executed by a controller of the processing chamber: exposing the substrate to a direct plasma of a co-flow of hydrogen and oxygen, and a remote plasma of a co-flow of hydrogen and oxygen.

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