Cleaning of chemical vapor deposition chamber

Abstract

A method of removing deposition residues from a processing chamber of a processing tool is provided. The method includes introducing a reactive cleaning substance generated by a remote plasma into the processing chamber. When the reactive cleaning substance generated by the remote plasma is introduced into the processing chamber, an in-situ plasma is formed at a processing station in the processing chamber.

Description

Background Art

[0001] The semiconductor device manufacturing process involves many steps such as material deposition, patterning and removal to form an integrated circuit on a substrate. Some steps involve the deposition of a carbon film. For example, carbon can be used as a hard mask material in the patterning process. The carbon film can be deposited by plasma enhanced chemical vapor deposition (PECVD). PECVD involves introducing a carbon precursor into a plasma in a reduced-atmosphere environment. The plasma generates reactive species from the carbon precursor. These reactive species react to form a carbon film on the substrate in the reduced-atmosphere environment. Summary of the invention

[0002] This summary is provided to introduce a selection of concepts in a simplified form, which will be further described in the specific implementation schemes below. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that address any or all of the disadvantages mentioned in any part of this disclosure.

[0003] Disclosed examples relate to cleaning a process chamber of a processing tool. In an exemplary method, a reactive cleaning species generated by a remote plasma is introduced into the process chamber. When the reactive cleaning species generated by the remote plasma is introduced into the process chamber, an in-situ plasma is formed at a process station in the process chamber.

[0004] In some such examples, generating the reactive species additionally or alternatively comprises comprising oxygen (O 2 ), nitrogen (N 2 ) and a gas mixture of one or more inert gases to produce a reactive oxygen-containing cleaning species.

[0005] In some such examples, the reactive oxygen-containing cleaning species additionally or alternatively comprises nitrogen oxide (NO) radicals.

[0006] In some such examples, generating the reactive cleaning species additionally or alternatively comprises generating a reactive cleaning species comprising nitrous oxide (N 2 O), hydrogen (H 2 ), or a combination thereof to produce the reactive oxygen-containing cleaning species.

[0007] In some such examples, forming the in-situ plasma additionally or alternatively includes applying radio frequency (RF) power to a substrate holder in the processing chamber to energize a cleaning species precursor in the processing chamber.

[0008] In some such examples, the RF power additionally or alternatively comprises a power within the range of 0.1 kW - 5.0 kW.

[0009] In some such examples, the method additionally or alternatively comprises monitoring the impedance of the in-situ plasma during a deposition residue cleaning cycle.

[0010] In some such examples, the method additionally or alternatively comprises detecting an end point of the deposition residue cleaning cycle by detecting a change in the impedance of the in-situ plasma over time, wherein the change in impedance represents a decrease in the amount of deposition residue in the processing chamber.

[0011] In some such examples, at least a portion of the in-situ plasma is additionally or alternatively located between a substrate holder of the processing chamber and a floor surface of the processing chamber.

[0012] In some such examples, at least a portion of the in-situ plasma is additionally or alternatively located in a gap between one or more surfaces of the processing chamber and a substrate handling component in the processing chamber.

[0013] Another example provides a processing tool. The processing tool includes a processing chamber that includes an inlet and a processing station. The processing station includes an in-situ plasma generator. The processing tool further includes a remote plasma generator that is coupled to the inlet of the processing chamber and a controller. The controller is configured to introduce a reactive cleaning species into the processing chamber using the remote plasma generator during a deposition residue cleaning cycle. The controller is further configured to form an in-situ plasma at the processing station using the in-situ plasma generator of the processing station when the reactive species generated by the remote plasma generator is introduced into the processing chamber.

[0014] In some such examples, the processing tool additionally or alternatively includes an O 2 source, an N 2 source, and an inert gas source that are in fluid communication with the remote plasma generator. The controller is additionally or alternatively configured to introduce O 2 , N 2 and the inert gas into the remote plasma generator during the deposition residue cleaning cycle.

[0015] In some such examples, the processing tool additionally or alternatively includes an N 2 O source, an H 2 source, or a combination thereof that is in fluid communication with the remote plasma generator, wherein the controller is configured to introduce N 2O and / or H 2 Introduced into the remote plasma generator.

[0016] In some such examples, the in-situ plasma generator additionally or alternatively includes an RF power supply configured to apply RF power to a substrate holder of the processing station.

[0017] In some such examples, the RF power source is configured to apply RF power within a power range of 0.1 kW - 5.0 kW.

[0018] In some such examples, the controller is additionally or alternatively configured to monitor impedance of the in-situ plasma during a deposition residue cleaning cycle.

[0019] In some such examples, the controller is additionally or alternatively configured to detect an endpoint of the deposition residue cleaning cycle by detecting a change in impedance of the in-situ plasma over time, wherein the change in impedance indicates a reduction in deposition residue in the processing chamber.

[0020] Another example provides a processing tool. The processing tool includes a processing chamber, the processing chamber includes a processing station. The processing station includes an in-situ plasma generator. The processing tool also includes a remote plasma generator and a controller. The controller is configured to introduce a reactive oxygen-containing cleaning substance into the processing chamber using the remote plasma generator during a carbon residue cleaning cycle. The controller is further configured to form an in-situ plasma at the processing station using the in-situ plasma generator of the processing station when the reactive cleaning substance generated by the remote plasma generator is introduced into the processing chamber. The controller is also configured to monitor the impedance of the in-situ plasma during the carbon residue cleaning cycle.

[0021] In some such examples, the in-situ plasma includes an RF power configured to apply RF power to a substrate holder in the processing chamber to energize a cleaning species precursor in the processing chamber.

[0022] In some such examples, the controller is additionally or alternatively configured to detect an end point of the carbon residue cleaning cycle by detecting a change in impedance of the in-situ plasma over time, wherein the change in impedance indicates a reduction in carbon residue in the processing chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic block diagram of an exemplary processing tool is shown.

[0024] Figure 2 Shows Figure 1 Schematic top view of a processing tool.

[0025] Figure 3 A graph depicting the change in impedance of an exemplary processing tool over time is shown.

[0026] Figure 4 A flow chart describing an exemplary method for cleaning deposition residues from a process chamber of a processing tool is shown.

[0027] Figure 5 A schematic diagram of an exemplary computing system is shown. DETAILED DESCRIPTION

[0028] The term "RF" stands for radio frequency.

[0029] The term "ALD" stands for atomic layer deposition.

[0030] The term "PEALD" stands for plasma enhanced atomic layer deposition.

[0031] The term "TALD" stands for Thermal Atomic Layer Deposition.

[0032] The term "CVD" stands for Chemical Vapor Deposition.

[0033] The term "PECVD" stands for plasma enhanced chemical vapor deposition.

[0034] The term "TCVD" stands for Thermal CVD.

[0035] The term "ALD" generally refers to a process that forms a film in one or more separate layers on a substrate by sequentially adsorbing precursors to a substrate and then chemically transforming the adsorbed precursors to form film layers. Examples of ALD processes include PEALD and TALD. PEALD and TALD utilize plasma of reactive gases and heat, respectively, to promote the chemical transformation of a precursor adsorbed to a substrate into a thin film on the substrate. The terms "growth," "deposition," and combinations thereof may also be used to represent film formation.

[0036] The term "CVD" generally refers to a process that forms a film on a substrate by a continuous flow of a gaseous precursor. PECVD utilizes plasma to form reactive species from gaseous precursors to aid in film formation. (TCVD) utilizes heat to promote film formation.

[0037] The terms "clean," "clean," and variations thereof generally refer to removing at least a portion of deposition residues from one or more surfaces in a processing chamber.

[0038] The term "cleaning material precursor" generally refers to a material that can be introduced into a plasma to produce a reactive cleaning material for cleaning deposited residues. Exemplary cleaning material precursors for cleaning carbon residues include: oxygen-containing cleaning precursors. Exemplary oxygen-containing cleaning precursors include: oxygen (O 2 ) and nitrous oxide (N 2 O).

[0039] The term "controller" generally refers to a computing system that is integrated with or otherwise in communication with a processing tool and that directs the performance of a process performed by the processing tool.

[0040] The term "deposition residue" generally refers to films deposited on surfaces other than substrates in a process chamber. Exemplary surfaces in a process chamber include: process gas inlet surfaces, substrate holder surfaces, and chamber walls. The term "carbon residue" generally refers to deposition residues that include carbon as a major component.

[0041] The term "deposition residue cleaning cycle" generally refers to a process cycle that includes introducing a cleaning substance precursor into a remote plasma in a remote plasma generator while also forming an in-situ plasma at a process station in a process chamber. The term "carbon residue cleaning cycle" generally refers to a deposition residue cleaning cycle in which the cleaning substance precursor includes an oxidant configured to oxidize carbon residue.

[0042] The term "endpoint" generally refers to the time at which a treatment is complete.

[0043] The term "flattening" generally refers to the decrease in the slope of a function over time.

[0044] The term "fluid communication" generally refers to the ability to conduct fluid between components.

[0045] The term "inert gas" generally refers to a gas that is substantially non-reactive in the processing environment. Exemplary inert gases include: nitrogen (N 2 ), helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe).

[0046] The term "in-situ plasma" generally refers to a plasma that is formed at a processing station in a processing tool.

[0047] The term "in-situ plasma generator" generally refers to a combination of components that can be used to form an in-situ plasma in a process chamber of a processing tool. Exemplary components include: an RF power supply; a matching network; and a showerhead or pedestal configured as an electrode in the process chamber.

[0048] The term "mixture" generally refers to a combination of two or more substances, where the substances are chemically different.

[0049] The term "susceptor" generally refers to a physical structure that is configured to support a substrate at a processing station.

[0050] The term "plasma" generally refers to a gas containing positive ions and free electrons.

[0051] The term "processing chamber" generally refers to a housing in which chemical and / or physical processes are performed on a substrate. The pressure, temperature, and atmosphere composition in the processing chamber may be controllable to perform these chemical and / or physical processes.

[0052] The term "process gas outlet" generally refers to a structure used to inject gas phase process chemicals into a process chamber of a process tool. The term "showerhead" generally refers to a process gas outlet that includes a plurality of holes distributed over an area. The process gas outlet may serve as an electrode in an in-situ plasma generator.

[0053] The term "processing station" may generally refer to the location within a processing chamber where a substrate is located during substrate processing.

[0054] The term "processing tool" may generally refer to a machine that includes a process chamber and other hardware configured to allow a process to be performed in the process chamber. PECVD and PEALD tools are examples of processing tools.

[0055] The term "free radical" generally refers to a chemical species that contains an unpaired electron.

[0056] The term "RF power supply" may generally refer to a device that outputs RF power to an electrode to generate a plasma in a process station in a process chamber or in a remote plasma chamber of a remote plasma generator.

[0057] The term "reactive cleaning species" may generally refer to one or more of ions or radicals generated by introducing a cleaning species precursor into a plasma. The term "reactive oxygen-containing cleaning species" generally refers to species that can oxidize carbon residues and are formed by introducing an oxygen-containing cleaning species precursor into a plasma.

[0058] The term "remote plasma" may generally refer to a plasma used to generate reactive cleaning species at a location remote from a processing station of a processing tool.

[0059] The term "remote plasma generator" may generally represent a combination of components that may be used to form a remote plasma at a location separate from a process station of a process chamber. The remote plasma generator includes a remote plasma chamber.

[0060] The term "remote plasma chamber" generally represents a housing in which a plasma is formed at a location of a processing station away from a processing chamber. The remote plasma chamber is configured to introduce reactive substances such as free radicals into the processing chamber after generation. The remote plasma chamber can be configured to produce inductively coupled plasma, capacitively coupled plasma, or microwave plasma. The remote plasma chamber can share a common vacuum system with the processing chamber so that the gas flow introduced into the remote plasma chamber enters the processing chamber. The remote plasma chamber can be configured to form inductively coupled plasma, capacitively coupled plasma, or microwave plasma. The remote plasma generated in the remote plasma chamber can produce reactive cleaning substances from the cleaning substance precursor introduced into the remote plasma. The inert gas flow can be included with the cleaning substance precursor flow.

[0061] The term "substrate" may generally refer to anything upon which a film may be deposited.

[0062] The term "substrate holder" may generally refer to a physical structure configured to support a substrate. A pedestal is an example of a substrate holder.

[0063] As described above, PECVD is a process for depositing materials on a substrate. For example, PECVD can be used to deposit a carbon film on a substrate by introducing a carbon-containing precursor into a plasma. The plasma produces a reactive carbon-containing species from the carbon-containing precursor. The reactive carbon-containing species that strikes the substrate forms a carbon film on the substrate. However, the deposition of the carbon film is not limited to the substrate. Instead, the carbon film is also deposited on the surface of the processing chamber. Examples include: chamber walls, exposed surfaces of a pedestal configured to support a substrate, and surfaces of a process gas outlet configured to distribute process chemicals into the processing chamber. Such carbon films are referred to herein as carbon residues. Similarly, other deposition processes, including other CVD processes and ALD processes such as PEALD, also form residues in the deposition chamber. Carbon residues and other other residues from deposition are generally referred to herein as deposition residues. Deposition residues can act as a source of particle contamination in the processing chamber.

[0064] Using existing methods, cleaning an entire process chamber can be challenging and time consuming. For example, the diffusion rate and flow distribution of reactive cleaning materials in the process chamber can cause relatively low concentrations of the reactive materials to reach some locations in the process chamber. In addition, at least some of the reactive materials may be extinguished (e.g., due to recombination or other reactions) before reaching some portions of the process chamber.

[0065] Therefore, the disclosed example relates to efficiently cleaning the deposition residue in the treatment chamber. In short, the reactive cleaning material produced by the remote plasma is introduced into the treatment chamber. As described above, the reactive cleaning material can undergo recombination or other reactions in the treatment chamber. In addition, the remote plasma does not convert all cleaning material precursors into reactive cleaning materials. Therefore, some cleaning material precursors also flow into the treatment chamber from the remote plasma generator. Therefore, when the reactive cleaning material is introduced from the remote plasma, the in-situ plasma is formed at the treatment station in the treatment tool to produce additional reactive cleaning materials in the treatment chamber. Compared to when only using remote plasma, the additional reactive cleaning materials produced by the in-situ plasma can allow the reactive cleaning materials to reach the difficult-to-clean areas of the treatment tool faster and with higher concentrations. In some such examples, the impedance of the in-situ plasma is monitored to detect the removal of the deposition residue from the treatment chamber. This enables the detection of the end point of the deposition residue cleaning cycle.

[0066] Figure 1 A schematic side view of an exemplary processing tool 100 is shown. Figure 2 A schematic top view of the processing tool 100 is shown. The processing tool 100 includes a processing chamber 102. Figure 2 , the processing chamber 102 includes four processing stations 104A, 104B, 104C, and 104D. In other examples, the processing chamber includes any other suitable number of processing stations, such as one, two, three, five, or more processing stations. Figure 1 In the illustration, processing stations 104C and 104D are located behind processing stations 104A and 104B, respectively, and therefore are not Figure 1 It is understandable that Figure 1 The structures of the processing stations 104A and 104B may also be included in the processing stations 104C and 104D.

[0067] continue Figure 1 , the processing stations 104A, 104B include substrate holders 106A, 106B, respectively. The processing stations 104A, 104B also include process gas outlets 108A, 108B, respectively. Each process gas outlet 108A, 108B includes a structure configured to dispense a gas-phase process chemical into the processing chamber 102 toward a substrate located on the corresponding substrate holder 106A, 106B. In some examples, each process gas outlet 108A, 108B includes a showerhead configured to dispense the gas-phase process chemical through a plurality of holes distributed throughout the area.

[0068] See again Figure 2The processing chamber 102 also includes a substrate handling system, which includes components, including arms 110A, 110B, 110C, 110D and a hub 111. The arms 110A, 110B, 110C, 110D are not shown in the figure for the purpose of clarity. Figure 1 The arms 110A, 110B, 110C, 110D are configured to place substrates at the processing stations 104A, 104B, 104C, 104D, respectively, to move substrates between the processing stations 104A, 104B, 104C, 104D, and / or to remove substrates from the processing chamber 102. In other examples, the substrate handling system may include a rotating disk.

[0069] Back to Figure 1 The processing tool 100 further includes a remote plasma generator 112. The remote plasma generator 112 includes a remote plasma chamber 114, an RF power supply 116, and an impedance matching network 118. In different examples, the remote plasma generator 112 may include a capacitively coupled plasma generator, an inductively coupled plasma generator, or a microwave plasma generator.

[0070] During the cleaning process, one or more cleaning substance precursor streams are introduced into the plasma in the remote plasma chamber 114 from one or more cleaning substance precursor sources described below. The cleaning substance precursors introduced into the remote plasma chamber 114 are activated by the plasma into reactive cleaning substances for introduction into the processing chamber 102. The operation of introducing the reactive substances into the chamber is schematically depicted at 120. In some examples, the reactive cleaning substances include reactive oxygen-containing cleaning substances. Examples include: oxygen (O 2 ) free radicals and nitrogen oxide (NO) free radicals. Ionic cleaning substances can also be generated.

[0071] The carbon residue reacts with the oxygen-containing cleaning material to form volatile carbon-oxygen compounds, such as carbon dioxide (CO 2 ) and carbon monoxide (CO). These volatile carbon compounds are then exhausted from the processing chamber 102.

[0072] As described above, the remote plasma generator 112 is in fluid communication with a cleaning material precursor source. Example cleaning material precursor sources include: 2 Source 122, nitrogen (N 2 ) source 124, and nitrous oxide (N 2 O) source 126. The remote plasma generator 112 may be from a source including O 2 and / or N 2 O plasma produces reactive oxygen species such as free radicals. Alternatively or additionally, the remote plasma generator 112 may generate a plasma containing O2 and N 2 The plasma produces nitric oxide (NO) free radicals. 2 The reactive oxygen species formed in the plasma containing NO, NO radicals, can have a longer radical lifetime. 2 The reactive oxygen species formed in the plasma, NO radicals, are able to reach further areas of the processing chamber 102 and remain active longer.

[0073] In some examples, from H 2 Source 128 of hydrogen (H 2 ) can be used as a cleaning species precursor. In such an example, H formed in the remote plasma as a reactive cleaning species 2 The free radicals can react with carbon residues to form methane (CH 4 ) and / or other volatile hydrocarbons. 2 It can also be used to adjust the oxidative properties of the oxidative reactive cleaning material. In other examples, the reactive cleaning material and / or the cleaning material precursor may additionally or alternatively include any other suitable material. Examples of other suitable materials include: carbon-free oxidants. More specific examples include: hydrogen peroxide (H 2 O 2 ), ozone (O 3 ) and water vapor (H 2 O).

[0074] The remote plasma generator 112 may also receive an inert gas flow from an inert gas source 130. Exemplary inert gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe). The inert gas may act as a diluent and / or may help stabilize the plasma containing the cleaning species precursor and reactive cleaning species.

[0075] In some examples, the RF power applied by the RF power source 116 of the remote plasma generator 112 is in a power range of 0.1 kW-15 kW. Generally speaking, a relatively high power plasma can produce a larger amount of reactive cleaning species. The RF power source 116 can generate RF power of any suitable frequency. In some examples, RF power can be generated with a frequency in the range of 300 kHz to 90 MHz. Examples of suitable frequencies include: 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz.

[0076] The processing tool 100 also includes an in-situ plasma generator 132. The in-situ plasma generator may generally refer to a plasma generator configured to generate an in-situ plasma in the processing chamber. The in-situ plasma generator 132 is configured to generate an in-situ plasma at the processing stations 104A, 104B, 104C, 104D, thereby facilitating the deposition of a film on a substrate in a PECVD process or a PEALD process. Exemplary plasmas 142A, 142B are shown between the processing gas outlets 108A, 108B and the substrate holders 106A, 106B of the processing stations 104A, 104B, respectively. As described in more detail below, the in-situ plasma generator may be used to provide energy for the unactivated cleaning material precursors and the recombined cleaning materials from the remote plasma generator. In this way, the in-situ plasma generator may generate additional reactive cleaning materials. This may assist the remote plasma generator to increase the concentration of reactive cleaning species and / or to more completely distribute the reactive cleaning species throughout the processing chamber relative to using the remote plasma generator alone.

[0077] The in-situ plasma generator 132 includes: an RF power supply 134 and a matching network 136. The RF power supply 134 is configured to apply RF power to the substrate holders 106A, 106B. In this example, the process gas outlets 108A, 108B are connected to an electrical ground 135. In other examples, RF power may be applied to the process gas outlets of the processing station instead of the substrate holders. The process gas outlets 108A, 108B and the substrate holders 106A, 106B may also be considered as components of the in-situ plasma generator 132. For example, the process gas outlets and substrate holders of each processing station are used to form a capacitively coupled plasma by the RF power applied to the substrate holder.

[0078] In some examples, the RF power generated by the in-situ plasma generator 132 is in the range of 0.1 kW-5.0 kW. Using RF power in this range helps avoid damage to the substrate holder and / or process gas outlet of the processing station. The RF power supply 134 can generate RF power of any suitable frequency. In some examples, RF power can be generated with a frequency in the range of 300 kHz to 90 MHz. Examples of suitable frequencies include: 400 kHz, 13.56 MHz, 27 MHz, 60 MHz, and 90 MHz.

[0079] exist Figure 1 In the schematic diagram of FIG. 1 , processing station 104A and processing station 104B are shown as receiving RF power from a common RF power supply 134 and matching network 136. In other examples, each processing station may include a separate RF power supply and matching network.

[0080] The processing tool 100 also includes a controller 138. The controller 138 includes a computing system that controls various controllable components of the processing tool 100. For example, the controller 138 is operable to control the remote plasma generator 112 and the in-situ plasma generator 132 to clean deposition residues from the processing chamber 102.

[0081] More specifically, the controller 138 is configured to control the remote plasma generator 112 during a deposition residue cleaning cycle to introduce the reactive cleaning species into the processing chamber 102. The reactive cleaning species includes free radicals that react with the deposition residue. As a result, the reactive cleaning species can remove at least a portion of the deposition residue from one or more surfaces in the processing chamber 102. In some examples, the reactive cleaning species can also include ions that are capable of reacting with the deposition residue.

[0082] In some examples, the controller is configured to introduce oxygen from the oxygen source 122 into the remote plasma chamber 114 at a rate in the range of 1 liter-50 liters per minute. In some examples, the controller is configured to introduce nitrogen from the nitrogen source 124 into the remote plasma chamber 114 at a rate in the range of 0.1 liter-1.0 liter per minute. Additionally, in some examples, the controller is configured to introduce an inert gas from the inert gas source 130 into the remote plasma chamber at a rate in the range of 1 liter-50 liters per minute. In other examples, any suitable gas flow can be provided to the remote plasma chamber 114.

[0083] The reactive cleaning substance 120 generated by the remote plasma is introduced into the processing chamber 102 via an inlet 140. In some examples, the inlet 140 is centered on a ceiling 141 of the processing chamber 102. This allows the reactive cleaning substance to be more evenly distributed throughout the processing chamber 102 than by introducing the remote plasma at a location that is not centered in the processing chamber. In other examples, the remote plasma generator can be configured to introduce the reactive cleaning substance into any other suitable location in the processing chamber. For example, each processing station can have a separate remote plasma generator.

[0084] In some examples, the processing tool 100 also includes one or more heaters. In the depicted example, the substrate holder 106A includes a first heater 168A, and the substrate holder 106B includes a second heater 168B. The heaters 168A, 168B can be controlled to heat the interior surface of the processing chamber 102 to a temperature in the range of 200°C to 800°C during the cleaning of the deposition residue. Such heating can be performed using a substrate holder heater, a process gas outlet heater, and / or any other suitable heater in the processing tool. These temperatures can promote oxidation of the deposition residue in the processing chamber 102. In other examples, the processing chamber may alternatively or additionally include other heaters. Examples include: heaters integrated into the process gas outlets 108A, 108B, and / or one or more chamber wall heaters.

[0085] In some examples, during cleaning, the pressure inside the processing chamber 102 is maintained at less than 760 Torr by the chamber exhaust system 115. In a more specific example, during cleaning, the total pressure inside the processing chamber 102 is maintained in the range of 1 Torr-10 Torr. Such a pressure can allow for sufficient mean free path for reactive cleaning species to migrate to surfaces in the chamber at a relatively large distance from the inlet 140.

[0086] As described above, in some instances, the reactive cleaning species generated by the remote plasma generator may not reach some portions of the process chamber 102 or may reach these portions of the process chamber at a relatively slow rate and / or at a relatively low concentration. Therefore, one advantage of the disclosure is that during a remote plasma chamber cleaning process, the controller 138 is further configured to control the in-situ plasma generator 132 to form an in-situ plasma at each of one or more of the process stations 104A, 104B, 104C, 104D. Figure 1Schematically shows the in-situ plasma 142A, 142B at the processing station 104A, 104B respectively. Each in-situ plasma 142A, 142B produces additional reactive cleaning substances in the processing chamber 102. For example, these additional reactive cleaning substances can be produced by supplying energy to the cleaning substance precursor provided to the processing chamber via the remote plasma generator 112. As described above, some of these cleaning substance precursors pass through the remote plasma generator 112 without being converted into reactive cleaning substances. In addition, reactive cleaning substances may be extinguished in the processing chamber (e.g., by recombination). Therefore, the in-situ plasma generator can form reactive cleaning substances from unactivated cleaning substance precursors and / or recombined reactive cleaning substances by the application of RF power. These additional reactive cleaning substances produced by the in-situ plasma can reach the parts of the processing chamber that may be challenging when using only remote plasma cleaning. Therefore, compared to the use of the remote plasma alone, the combination of the remote plasma and the in-situ plasma allows the processing tool to clean the processing chamber 102 in a shorter amount of time. The combination also allows for easier cleaning of hard to reach areas of the process chamber 102 .

[0087] Due to the electric field formed between the substrate holder 106A, 106B and other grounded surfaces of the process chamber 102 than the process gas outlets 108A, 108B, an in-situ plasma may be formed at other locations in the process chamber 102 other than between the process gas outlets of the process station and the substrate holder. Forming plasma at other locations may help clean hard-to-reach locations in the process chamber 102. For example, by applying RF power to the substrate holder 106A and grounding the bottom surface 146, an in-situ plasma 144A may be formed in the space between the substrate holder 106A and the bottom surface 146 of the process chamber 102. Similarly, by applying RF power to the substrate holder 106B and grounding the bottom surface, an in-situ plasma 144B may be formed in the space between the substrate holder 106B and the bottom surface 146 of the process chamber 102. The in-situ plasmas 144A and 144B may help clean underneath the substrate holders 106A, 106B. As another example, by applying RF power to the substrate holder 106A and grounding the chamber wall of the process chamber 102, an in-situ plasma 148A can be formed adjacent to a chamber wall location 150A of the process chamber. This can include a corner location 152A adjacent to where the bottom surface 146 intersects the chamber wall location 150. A similar in-situ plasma 148B can be formed adjacent to the process station 104B and other process stations. As yet another example, due to the electric field extending between the substrate holders 106A, 106B and the ceiling 141, in-situ plasmas 166A, 166B can be formed in the space between the process gas outlets 108A, 108B, respectively, and the ceiling 141 of the process chamber.

[0088] As described above, the in-situ plasma generator can be used to form an in-situ plasma to facilitate cleaning of hard-to-reach locations. For example, the hub 111 and arms 110A, 110B, 110C, 110D ( Figure 2 ) may be supported by the base 154 and separated from the base 154 by a gap. Deposition residues in the gap may be difficult to clean because at least a portion of the base 154 is in the shadow of the hub 111 from the perspective of the inlet 140. However, reactive cleaning species formed by the in-situ plasma may more easily reach the gap between the hub 111 and the base 154. In addition, in some examples, the in-situ plasma 156 may be formed between substrate handling components (e.g., arms 110A, 110B, 110C, 110D and the hub 111) and one or more surfaces of the processing chamber 102 (e.g., the bottom surface 154). Forming plasma at these locations may generate reactive cleaning species at these locations, thereby helping to reduce the time of the cleaning process. This may also cause some ion impacts on these surfaces in these locations, thereby etching away at least some of the deposition residues.

[0089] In some examples, the endpoint of the cleaning process can be estimated. In such examples, the time allocated for the chamber cleaning process can be overestimated to ensure that a thorough cleaning is performed. Overestimating the cleaning time can result in lower yields compared to actively monitoring the cleaning. Therefore, in some examples, the controller 138 is configured to actively monitor data about the chamber status to detect the cleaning endpoint. For example, the controller can use the impedance sensing system 160 to monitor the impedance of the in-situ plasma to detect the removal or reduction of the deposition residue from the chamber 102. During the cleaning process, a sensor such as CO 2 The presence of volatile oxidized carbon species such as oxidized carbon species changes the impedance of the plasma. Therefore, the in-situ plasma generator 132 may include one or more sensors to implement an impedance sensing system 160. For example, the in-situ plasma generator 132 may sense the current and voltage of the RF power supplied to the substrate holder 106A and / or the substrate holder 106B using an ammeter or a voltmeter, respectively. The impedance can be determined by the sensed current and voltage. As cleaning proceeds, the impedance changes as the concentration of oxidized carbon species in the processing chamber changes.

[0090] When the impedance of the in-situ plasma reaches a steady state, the controller 138 detects the completion of the cleaning cycle. For example, the impedance of the in-situ plasma tends to be flat over time, which can be used for cleaning endpoint detection. For example, Figure 3 A curve 300 is shown depicting impedance 302 versus time 304 during a PECVD chamber carbon residue cleaning process utilizing a remote plasma (e.g., from the remote plasma generator 112) and an in-situ plasma (e.g., from the in-situ plasma generator 132). In the example curve 300, the measured impedance 302 of the in-situ plasma decreases as the concentration of oxidized carbon species decreases. When the slope of the impedance 302 flattens, as indicated by arrow 306, this indicates that the cleaning process has been completed. In this manner, the impedance reaches a steady state value due to the removal and / or reduction of the deposition residue. Thus, the flattening of the slope of the impedance may indicate the completion of the deposition residue cleaning cycle. In some examples, the completion of the deposition residue cleaning cycle occurs when the carbon residue is completely or substantially completely removed. The term "substantially completely" may generally represent that enough deposition residue is removed such that the impedance slope shows no change over time, but some deposition residue remains on the chamber surfaces. In other examples, completion of the deposition residue cleaning cycle occurs when a predetermined amount of carbon residue is removed to prevent contamination (eg, when a sufficient amount of carbon residue is removed to prevent particles from breaking free and contaminating substrates in the processing chamber).

[0091] Back to Figure 1, data from the impedance sensing system 160 is used as an input to the controller 138. In some examples, the controller 138 is configured to adjust the RF power source 116 of the remote plasma generator 112 and / or the RF power source 134 of the in-situ plasma generator 132 based on the impedance. For example, the controller 138 may include code that implements the cleaning endpoint detection module 162. Using the code, the controller 138 may detect a flattening of impedance changes over time (e.g., Figure 3 ) to terminate the deposited residue cleaning cycle.

[0092] Figure 4 A flow chart is shown that describes an exemplary method 400 for cleaning deposition residues from a process chamber of a process tool. The method 400 may be used to clean the process tool 100 or any other suitable process tool including a remote plasma generator and an in-situ plasma generator. Figure 4 The dashed outlines in represent optional steps.

[0093] At 402, the method 400 includes introducing a reactive cleaning species generated by a remote plasma into the processing chamber. Introducing the reactive cleaning species into the processing chamber allows the reactive cleaning species to remove at least a portion of deposition residues from one or more surfaces in the processing chamber.

[0094] In some examples, at 404, generating the reactive cleaning species includes: 2 、N 2 and one or more inert gases to produce a reactive oxygen-containing cleaning species. In some examples, the oxygen-containing cleaning species precursor includes an oxidant, such as O 2 , H 2 O 2 , H 2 O(g), O 3 , and / or N 2 O. In some more specific examples, as shown in 406, the reactive oxygen-containing cleaning species include: 2 and N 2 The oxygen-containing free radicals and / or nitric oxide (NO) free radicals generated by the gas mixture of process 404. For example, these NO free radicals can be generated by the O in the gas mixture of process 404. 2 With N 2The NO radicals may be formed by a reaction between NO and NO. These NO radicals may have a longer radical lifetime than other free radical species. Therefore, these NO radicals may remain active for a longer time. This may allow these NO radicals to reach further areas of the processing chamber than other reactive cleaning species. The gas mixture may also include an inert gas. Examples include: He, Ne, Ar, Kr, and / or Xe. The inert gas may act as a diluent and / or may help stabilize the plasma.

[0095] In some examples, at 408, generating the reactive cleaning species comprises: 2 O, H 2 , or a combination thereof to produce reactive oxygen-containing cleaning substances. For example, Figure 1 The N 2 O source 126 is configured to supply N 2 O to remote plasma generator 112. N 2 O can produce O 2 free radicals and help stabilize the plasma. 2 Introduced into the remote plasma chamber to generate H 2 Free radical. 2 The free radicals can help to adjust the oxidative nature of the atmosphere in the processing chamber. In addition, the H 2 The free radicals may also react with carbon residues to form volatile hydrocarbon species.

[0096] At 410, the method 400 includes: forming an in-situ plasma at a processing station in a processing chamber when a reactive cleaning species generated by the remote plasma is introduced into the processing chamber. Figure 1 The in-situ plasma generator 132 is configured to generate additional reactive cleaning species in the processing chamber 102. The in-situ plasma generator can form reactive cleaning species from unreacted cleaning species precursors flowing in from the remote plasma generator. The in-situ plasma generator can also form reactive cleaning species from reactive cleaning species that have been extinguished (e.g., by recombination). This can result in a greater concentration of the reactive cleaning species in the processing chamber and / or the formation of a different distribution of the reactive cleaning species than using only the remote plasma generator. This can also help clean hard-to-reach locations in the processing chamber.

[0097] In some examples, forming the in-situ plasma at 412 includes applying radio frequency (RF) power to a substrate holder in the process chamber to energize a cleaning substance precursor in the process chamber. In other examples, the RF energy may be applied to a process gas outlet, or any other suitable electrode in the deposition chamber.

[0098] In some examples, the RF power comprises a power in the range of 0.1 kW - 5.0 kW, as shown at 414. As described above, this power range can promote the formation of the additional reactive cleaning species while avoiding damage to components in the processing chamber.

[0099] As described above, when plasma is formed between the process gas outlet and the substrate holder, plasma may also be formed at other locations in the chamber. As shown at 416, in some examples, a portion of the in-situ plasma may be located between the substrate holder of the process chamber and the bottom surface of the process chamber. This may more efficiently clean structures in the gap between the substrate holder and the bottom surface of the process chamber 102 than using only the reactive cleaning species generated by the remote plasma generator.

[0100] Also, in some examples, a portion of the in-situ plasma is located in a gap between one or more surfaces of the processing chamber and a substrate handling component in the processing chamber at 418. This can more efficiently clean surfaces in such gaps than using only a remote plasma.

[0101] As described above, the impedance of the in-situ RF plasma varies with the concentration of oxidized deposition residue species in the process chamber. Therefore, as described at 420, in some examples, the method 400 includes monitoring the impedance of the in-situ plasma during a deposition residue cleaning cycle. For example, Figure 1 The controller 138 is configured to monitor the impedance of the in-situ plasma to detect the removal of the deposition residue.

[0102] In some more specific examples, the impedance reaches a steady state when cleaning is complete. For example, the impedance of the in-situ plasma over time can be flattened at the end of the cleaning process. Therefore, at 422, in some examples, the method 400 also includes detecting the end of the deposition residue cleaning cycle by detecting a change in the impedance of the in-situ plasma over time. The change in impedance indicates a decrease in the amount of deposition residue in the processing chamber.

[0103] Thus, the above-described systems and methods can be used to remove deposition residues from a processing chamber of a processing tool. Compared to only by the remote plasma, the combination of the remote plasma and the in-situ plasma can provide a more efficient cleaning of the processing chamber. In addition, in some examples, the impedance of the in-situ plasma indicates the removal of the deposition residue from the processing chamber. This allows real-time detection of the end point of the deposition residue cleaning cycle. In some examples, the methods and processes described herein can be combined with a computing system of one or more computing devices. In particular, such methods and processes can be implemented as an executable computer application, a network-accessible computing device, an application programming interface (API), a database, or a combination of the above and / or other computing resources.

[0104] Figure 5 A simplified representation of a computing system 500 is depicted that is configured to provide any or all of the computing functionality described herein. For example, computing system 500 may take the form of one or more personal computers, server computers, and computers integrated with processing tools. Controller 138 is an example of computing system 500.

[0105] The computing system 500 includes a logic subsystem 502 and a storage subsystem 504. The computing system 500 may optionally include a display subsystem 506, an input subsystem 508, a communication subsystem 510, and / or Figure 5 Other subsystems not shown.

[0106] The logic subsystem 502 includes one or more physical devices that are configured to execute instructions. For example, the logic subsystem may be configured to execute instructions that are part of one or more applications, services, programs, routines, databases, objects, components, data structures, or other logical structures. Such instructions may be implemented to perform tasks, implement data forms, convert the states of one or more components, implement technical effects, or otherwise achieve the desired results of the disclosed technology as described herein.

[0107] The logic subsystem may include one or more hardware processors configured to execute software instructions. Additionally or alternatively, the logic subsystem may include one or more hardware or firmware devices configured to execute hardware or firmware instructions. The processor of the logic subsystem may be single-core or multi-core, and the instructions executed thereon may be configured for sequential, parallel and / or distributed processing. The individual components of the logic subsystem may be optionally distributed between two or more individual devices, which may be remotely located and / or configured for coordinated processing. Aspects of the logic subsystem may be virtualized and executed by remotely accessible network computing devices configured in a cloud computing structure.

[0108] The storage subsystem 504 includes one or more physical devices configured to temporarily and / or permanently store computer data, such as data and instructions executable by the logic subsystem. When the storage subsystem includes two or more devices, the devices may be parallel and / or remotely located. The storage subsystem 504 may include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, location addressable, archive addressable, and / or content addressable devices. The storage subsystem 504 may include removable and / or built-in devices. As the logic subsystem executes instructions, the state of the storage subsystem 504 may be switched - for example, to store other data.

[0109] The storage subsystem 504 may include removable and / or built-in devices. The storage subsystem 504 may include optical storage (e.g., CD, DVD, HD-DVD, Blu-ray disc, etc.), semiconductor storage (e.g., RAM, EPROM, EEPROM, etc.), and / or magnetic storage, etc. The storage subsystem 504 may include volatile, non-volatile, dynamic, static, read / write, read-only, random access, sequential access, location addressable, file addressable, and / or content addressable devices.

[0110] Aspects of logic subsystem 502 and storage subsystem 504 may be integrated together into one or more hardware logic components. Such hardware logic components may include program-specific and application-specific integrated circuits (PASIC / ASIC), program-specific and application-specific standard products (PSSP / ASSP), single-chip systems (SOCs), and complex programmable logic devices (CPLDs).

[0111] The logic subsystem and the storage subsystem may collaborate to instantiate one or more logic machines. As used herein, the term "machine" is used to collectively refer to a combination of hardware, firmware, software, instructions, and / or any other components to provide computer functionality. That is, "machine" is never an abstract concept and all have physical form. A machine may be instantiated by a single computing device, or a machine may include two or more subcomponents instantiated by two or more different computing devices. In some implementations, a machine includes a local component (e.g., a software application executed by a computer processor) that collaborates with a remote component (e.g., a cloud computing device provided by a network of server computers). The software and / or other instructions that give a particular machine its functionality may be optionally stored as one or more non-executable modules on one or more suitable storage devices.

[0112] When included, the display subsystem 506 can be used to present a visual representation of the data stored by the storage subsystem 504. The visual representation can take the form of a graphical user interface (GUI). When the methods and processes described herein change the data stored by the storage subsystem, and thus change the state of the storage subsystem, the state of the display subsystem 506 may also be transformed to visually represent the change in the underlying data. The display subsystem 506 can include one or more display devices, which virtually use any type of technology. Such a display device can be combined with the logic subsystem and the storage subsystem in a shared enclosure, or such a display device can be a peripheral display device.

[0113] When included, the input subsystem 508 may include or may interact with one or more user input devices (e.g., keyboard, mouse, touch screen). In some examples, the input subsystem may include or interact with selected natural user input (NUI) components. Such components may be integrated or peripheral, and the conversion and / or processing of input actions may be handled on-board or off-board. Exemplary NUI components may include microphones for voice and / or sound recognition, and infrared, color, stereo, and / or depth cameras for machine vision and / or gesture recognition.

[0114] When included, the communication subsystem 510 can be configured to communicatively couple the computing system 500 with one or more other computing devices. The communication subsystem 510 can include wired and / or wireless communication devices compatible with one or more different communication protocols. As non-limiting examples, the communication subsystem can be configured to communicate using a wireless telephone network, or a wired or wireless local area network or wide area network. In some examples, the communication subsystem can allow the computing system 500 to send messages to other devices and / or receive messages from other devices over a network such as the Internet.

[0115] The disclosure is presented by way of example and with reference to the associated accompanying drawings. In one or more diagrams, substantially identical components, processing steps, and other elements may be identified coordinately and described with minimal repetition. However, it should be noted that the elements identified coordinately may also differ to some extent. It should be further noted that some diagrams may be schematic and not depicted to scale. Different drawing scales, aspect ratios, and the number of components shown in the figures may be intentionally distorted to make specific features or relationships easier to observe.

[0116] As used herein, "and / or" is defined to include or∨, as enumerated by the truth table below: A B A∨B real real real real Fake real Fake real real Fake Fake Fake

[0117] As used herein, the term "one or more of A or B" includes: A, B, or a combination of A and B. The term "one or more of A, B, or C" is equivalent to A, B, and / or C. Therefore, as used herein, "one or more of A, B, or C" includes: A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

[0118] It should be understood that the configurations and / or methods described herein are exemplary in nature, and these examples should not be considered restrictive, as many variations are possible. The specific routines or methods described herein may represent one or more of any number of strategies. Therefore, the various actions shown and / or described may be performed in the order shown and / or described, in other orders, in parallel, or omitted. Likewise, the order of the above-mentioned processing may be changed.

[0119] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts, and / or properties disclosed herein, as well as any and all equivalents thereof.

Claims

1. A method for cleaning a process chamber of a process tool, the method comprising: introducing reactive cleaning species generated by a remote plasma into the processing chamber; and When the reactive cleaning species generated by the remote plasma is introduced into the process chamber, an in-situ plasma is formed at a process station in the process chamber.

2. The method according to claim 1, wherein the reactive cleaning species and the comprising: 2 ), nitrogen (N 2 ) and one or more inert gases to produce a reactive oxygen-containing cleaning species.

3. The method of claim 2, wherein the reactive oxygen-containing cleaning species comprises nitric oxide (NO) radicals.

4. The method of claim 1, wherein generating the reactive cleaning species comprises: 2 O), hydrogen (H 2 ), or a combination thereof to produce the reactive oxygen-containing cleaning species.

5. The method of claim 1, wherein forming the in-situ plasma comprises applying radio frequency (RF) energy to a substrate holder in the processing chamber. The method of claim 5 , wherein the RF power comprises a power within the range of 0.1 kW-5.0 kW.

7. The method of claim 1, further comprising monitoring impedance of the in-situ plasma during a deposition residue cleaning cycle.

8. The method of claim 7, further comprising detecting an end point of the deposition residue cleaning cycle by detecting a change in impedance of the in-situ plasma over time, wherein the change in impedance indicates a reduction in an amount of deposition residue in the processing chamber.

9. The method of claim 1, wherein at least a portion of the in-situ plasma is located between a substrate holder of the processing chamber and a bottom surface of the processing chamber.

10. The method of claim 1, at least a portion of the in-situ plasma being located in a gap between one or more surfaces of the processing chamber and a substrate handling component in the processing chamber.

11. A processing tool comprising: a processing chamber comprising an inlet and a processing station comprising an in-situ plasma generator; a remote plasma generator coupled to the inlet of the processing chamber; and A controller configured to, during a deposit residue cleaning cycle: introducing a reactive cleaning species into the processing chamber using the remote plasma generator; and When the reactive cleaning species generated by the remote plasma generator is introduced into the processing chamber, an in-situ plasma is formed at the processing station using the in-situ plasma generator of the processing station.

12. The processing tool of claim 11, further comprising an O 2 Source, N 2 a source of inert gas and a source of inert gas, and wherein the controller is configured to transfer O 2 、N 2 and an inert gas are introduced into the remote plasma generator.

13. The processing tool of claim 11, further comprising an N 2 O source, H 2 source, or a combination thereof, wherein the controller is configured to transfer N 2 O and / or H 2 Introduced into the remote plasma generator.

14. The processing tool of claim 11, wherein the in-situ plasma generator comprises a radio frequency (RF) power supply configured to apply RF power to a substrate holder of the processing station.

15. The processing tool according to claim 14, wherein the RF power supply is configured to apply an RF power in the range of 0.1 kW - 5.0 kW.

16. The processing tool of claim 11, wherein the controller is further configured to monitor impedance of the in-situ plasma during a deposition residue cleaning cycle.

17. The processing tool of claim 16, wherein the controller is configured to detect an end point of the deposition residue cleaning cycle by detecting a change in the impedance of the in-situ plasma over time, wherein the change in the impedance indicates a reduction in deposition residues in the processing chamber.

18. A processing tool comprising: a processing chamber comprising a processing station comprising an in-situ plasma generator; a remote plasma generator; and A controller configured to, during a carbon residue cleaning cycle: introducing a reactive oxygen-containing cleaning species into the processing chamber using the remote plasma generator; forming an in-situ plasma at the processing station using the in-situ plasma generator of the processing station when the reactive cleaning species generated by the remote plasma generator is introduced into the processing chamber; and The impedance of the in-situ plasma is monitored during the carbon residue cleaning cycle.

19. The processing tool of claim 18, wherein the in-situ plasma generator comprises a radio frequency (RF) power supply configured to apply RF power to a substrate holder in the processing chamber to energize a cleaning substance precursor in the processing chamber.

20. The processing tool of claim 18, wherein the controller is further configured to detect an end point of the carbon residue cleaning cycle by detecting a change in the impedance of the in-situ plasma over time, wherein the change in the impedance indicates a reduction in carbon residue in the processing chamber.

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