Parasitic plasma detection apparatus and method

Abstract

Apparatuses for detecting plasma are disclosed, as well as reactor systems and methods for detecting plasma comprising the apparatuses. Exemplary apparatuses include an ion collector and a meter configured to measure a change in one or more of a current, a charge, or a potential difference. Exemplary apparatuses also include a controller configured to generate one or more signals indicative of a presence of a parasitic plasma and / or a size and intensity of the parasitic plasma.

Description

Technical Field

[0001] This disclosure generally relates to plasma detection apparatus, methods for detecting parasitic plasma, and devices including plasma detection apparatus. More specifically, examples of this disclosure relate to methods and apparatus for detecting ions that can be generated by parasitic plasma. Background Technology

[0002] In semiconductor manufacturing, plasma is used in a variety of processes and systems. For example, plasma is often used to generate active materials that can be used in deposition, etching, or cleaning processes.

[0003] Some systems that use plasma include a reaction space between parallel electrodes, where plasma is intended to be generated. However, parasitic plasmas are often generated in other spaces within the system, such as exhaust systems or other cavities within the system. These parasitic plasmas can damage components of the system, generate unwanted particles that may cause defects on the substrate being processed, or cause processing variations on the substrate being processed.

[0004] Parasitic plasmas can be detected by matching networks, temperature changes in system components, or using optical sensors configured to detect radiation emitted from parasitic plasmas. This technique may detect plasmas slowly and / or fail to detect weak parasitic plasmas before causing significant damage to system components. Therefore, there is a desire for improved parasitic plasma detection devices and systems, such as those that can detect parasitic plasmas directly and / or before major damage to system components occurs.

[0005] Any discussion set forth in this section (including discussions of problems and solutions) is included in this disclosure for the purpose of providing background information only. Such discussion should not be construed as an admission that any or all information was known at the time of making this invention or otherwise constitutes prior art. Summary of the Invention

[0006] This synopsis is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the following detailed description of exemplary embodiments of this disclosure. This synopsis is not intended to require the identification of key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0007] The various examples described herein relate to parasitic plasma detection devices, reactor systems including parasitic plasma detection devices, and methods for detecting parasitic plasma. As explained below, the methods described herein can be used to manufacture electronic devices, such as semiconductor devices. Exemplary devices can be able to detect parasitic plasma in space by detecting the generation of ions. Exemplary reactor systems can include detection devices placed in spaces where parasitic plasma may be generated. If a signal from the detection device exceeds a threshold or exceeds a threshold within a certain time period, the exemplary reactor system can be configured to interlock or stop providing plasma (e.g., RF) power. Exemplary methods can use the detection devices or reactor systems described herein to detect parasitic plasma.

[0008] According to one or more embodiments, an exemplary apparatus for detecting plasma is provided. The exemplary apparatus includes a panel, an ion collector, and a meter connected to the ion collector. The exemplary apparatus is configured to detect the presence of (e.g., positive and / or negative) ions, such as ions generated by plasma. The panel of the exemplary apparatus may be configured to be mounted in or connected to (e.g., an inner) wall of a reactor system in a space where parasitic plasma may be generated. The ion collector may extend through the panel and be connected to the meter. The meter may be configured to measure at least one of current, charge, or potential difference. The ion collector may be configured to contact ions generated by parasitic plasma. When ions contact the ion collector, the meter may measure a change in at least one of current, charge, or potential difference. The meter may generate an output indicating a change in at least one of current, charge, or potential difference. The output may indicate the presence of parasitic plasma that generates ions. The exemplary apparatus may also include a controller that can convert the output of the meter into a signal indicating the presence of plasma or a relative amount of ion generation.

[0009] The exemplary device may also include a grid and a generator connected to the grid. The grid may have a first portion extending through the panel to connect to the generator, and a second portion including coils, loops, or a series of (e.g., concentric) loops around an axis. The second portion may surround or encircle the ion collector. The generator may be positioned on the same side of the panel as the meter. The generator may be configured to generate at least one of an AC voltage, a positive DC voltage, or a negative DC voltage to the grid. In operation, the voltage generated to the grid can create an electric field that can capture ions and direct them toward the ion collector.

[0010] According to one or more embodiments, an exemplary reactor system with parasitic plasma detection is provided. The exemplary reactor system includes a reaction chamber, a controller, a base disposed within the reaction chamber, a reaction space at least partially defined by a top surface of the base, a sub-space adjacent to the reaction space, and a detection device mounted to a wall in the sub-space. The exemplary reactor system can be configured to generate plasma in the reaction space. The exemplary reactor system can be designed to generate plasma only in the reaction space, but the exemplary reactor system can generate parasitic plasma in the sub-space. The detection device is configured to detect the generation of ions in the sub-space. The detection device can be a detection device as described herein. The detection device can generate an output to the controller indicating a change in at least one of current, charge, or potential difference. The controller can be configured to interlock the reactor system or stop plasma generation if the output from the detection device exceeds a threshold.

[0011] According to one or more embodiments, an exemplary method for detecting parasitic plasma is provided. The exemplary method can detect parasitic plasma and stop plasma generation and minimize damage caused by the parasitic plasma. The exemplary method includes providing a reactor system comprising a reaction space and a secondary space adjacent to the reaction space, providing a detection device in the secondary space, generating plasma in the reaction space, and generating a signal from the detection device indicating the presence of parasitic plasma in the secondary space. The reactor system and detection device can be as described herein.

[0012] The exemplary method may also include sending the output from the detection device to the controller. The exemplary method may also include interlocking the reactor system or stopping plasma generation if the output exceeds a threshold.

[0013] These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings; the invention is not limited to any particular embodiment disclosed. Attached Figure Description

[0014] Embodiments of this disclosure can be more fully understood when considered in conjunction with the following illustrative drawings, and by referring to the detailed description and claims.

[0015] Figure 1 An apparatus for detecting plasma according to one or more embodiments of the present disclosure is shown;

[0016] Figure 2 Another apparatus for detecting plasma according to one or more embodiments of the present disclosure is shown;

[0017] Figure 3 Examples of reactor systems according to one or more examples of this disclosure are shown;

[0018] Figure 4 A method for detecting parasitic plasma according to one or more embodiments of the present disclosure is shown.

[0019] It should be understood that the elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements to aid in understanding the embodiments shown in this disclosure. Detailed Implementation

[0020] The following description of exemplary embodiments of the methods, structures, apparatuses, and systems is merely illustrative and for purposes of explanation only; the following description is not intended to necessarily limit the scope of this disclosure or the claims. Furthermore, the description of multiple embodiments having the described features is not intended to exclude other embodiments having additional features or other embodiments including different combinations of the described features. For example, various embodiments are set forth as exemplary embodiments and may be recited in the dependent claims. Unless otherwise stated, exemplary embodiments or components thereof may be combined or may be applied separately from each other.

[0021] The illustrations presented herein are not intended to be actual views of any particular system, structure, or device, but are merely idealized representations used to describe embodiments of this disclosure.

[0022] The specific embodiments shown and described are illustrative of the invention and its best mode, and are not intended to limit the scope of aspects and embodiments in any way. In fact, for the sake of brevity, conventional manufacturing, connection, fabrication, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in the actual system, and / or may not exist in some embodiments.

[0023] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Unless otherwise stated, expressions such as “at least one of…” modify the entire column of elements when following an element in the column, and not necessarily any individual element in that column.

[0024] As used in this article, the singular forms “a,” “one,” and “the” are intended to include both singular and plural forms, unless the context otherwise requires.

[0025] As used herein, the term "substrate" can refer to any one or more underlying materials that can be used to form or on which devices, circuits, or films are formed. A substrate may comprise a bulk material, such as silicon (e.g., single-crystal silicon), other group IV materials (e.g., germanium), or compound semiconductor materials (e.g., group III-V or II-VI semiconductors), and may comprise one or more layers overlaid or under the bulk material. For example, a substrate may comprise silicon or silicon-germanium. In some cases, a substrate may comprise an oxide (e.g., silicon oxide).

[0026] In this disclosure, any two numbers of a variable may constitute a feasible range of the variable, and any range indicated may include or exclude endpoints. Furthermore, any value of the indicated variable (whether or not it is indicated by “about”) may refer to an exact value or an approximate value and include equivalents, and may refer to an average, median, representative value, multi-value, etc. For example, the value of a variable may include + / -20%, or + / -10%, or + / -5%, or + / -1%, or + / -0% of the value of the listed variable. Additionally, in this disclosure, the terms “comprising,” “including,” “consisting of,” and “having” may independently mean “generally or broadly comprising,” “including,” “substantially constitutes,” or “consisting of” in some embodiments. The meaning of any definition in this disclosure does not necessarily exclude the common and customary meaning in some embodiments.

[0027] Figure 1 and Figure 2 Devices 100 and 200 for detecting plasma according to exemplary embodiments of the present disclosure are shown. Devices 100 and 200 each include an ion collector 110, a grid 120, a panel 130, a generator 140 connected to the grid 120, a meter 150, a controller 160, a modulator 170, and a switch 180 connected to the modulator 170. Device 200 also includes an ion collector 110, a grid 120, a panel 130, a generator 140 connected to the grid 120, a meter 150, a controller 160, a modulator 170, and a switch 180 connected to the modulator 170. Device 200 is similar to device 100, except that device 200 has a second portion 221 of the grid 120, which is different from that of device 100. Unless specifically indicated, device 200 may have the same structure, components, functions, and configuration as device 100.

[0028] In some embodiments, the device 100 is configured to detect (e.g., positive and / or negative) ions generated from a plasma. In some embodiments, the device 100 is configured to generate an output indicating the number of ions detected. In some embodiments, the device 100 is configured to generate a signal indicating the presence of a parasitic plasma. In some embodiments, the device 100 is configured to generate a signal indicating the intensity or magnitude of the parasitic plasma.

[0029] In some embodiments, the ion collector 110 comprises a conductive material, such as a metal. In some embodiments, the ion collector 110 comprises one or more of copper, silver, gold, steel, aluminum, and brass. In some embodiments, the ion collector 110 is (e.g., a straight) wire. The ion collector 110 extends through panel 130 and connects to meter 150. In some embodiments, the ion collector 110 has no voltage bias or is at (e.g., nearly) ground potential when not in contact with ions. In some embodiments, the ion collector 110 has no net charge when not in contact with ions. In some embodiments, the ion collector 110 has no net current when not in contact with ions. The ion collector 110 is configured to generate a current, a potential change, or a charge change when it comes into contact with ions.

[0030] Meter 150 is configured to measure changes in current, potential, or charge when ions come into contact with ion collector 110. Meter 150 can be any suitable meter capable of measuring changes in current, potential, or charge when ions come into contact with ion collector 110. For example, meter 150 can be an electrometer. Meter 150 produces an output (e.g., to controller 160) representing changes in current, potential, or charge. Thus, the output can indicate the presence of ions, such as ions generated by plasma. In some embodiments, meter 150 is configured to measure positive changes in charge or potential and / or negative changes in charge or potential. In some embodiments, meter 150 is further grounded. In some embodiments, meter 150 includes an amplifier configured to amplify the output.

[0031] Controller 160 includes electronic circuitry and software for collecting, storing, and analyzing output from meter 150. In some embodiments, controller 160 is configured to generate one or more signals based on the output from meter 150. In some embodiments, controller 160 includes an amplifier configured to amplify the output from meter 150. In some embodiments, controller 160 is configured to generate a first signal indicating whether a change in current, potential, or charge exceeds a first threshold. In some embodiments, controller 160 is configured to generate a second signal indicating whether a change in current, potential, or charge exceeds a second threshold within a first time period. In some embodiments, controller 160 is configured to generate a third signal indicating the ion collection rate (and therefore the rate of ion generation from the plasma). In some embodiments, controller 160 is configured to send one or more of the first, second, or third signals to other components, such as other system components, or to a user interface.

[0032] In some embodiments, the device 100 does not include any solid material surrounding or shielding the ion collector 110 from its environment or the space in which the device is used to detect plasma (other than the grid 120 and modulator 170). In some embodiments, the device does not include any solid material (other than the grid 120 and modulator 170) obstructing the line of sight from the ion collector 110 to the space in which the device is used to detect plasma. In some embodiments, the device does not include any solid material obstructing the line of sight from the ion collector 110 to the space in which the device is used to detect plasma (other than the grid 120 and modulator 170).

[0033] The grid 120 may surround a portion of the ion collector 110 (e.g., along the axis of the ion collector 110). The grid 120 does not (e.g., directly) contact the ion collector 110. The grid 120 may include a conductive material, such as a metal. Exemplary materials include copper, silver, gold, aluminum, steel, and brass. The grid 120 may include a first portion 123 and a second portion 121. In some embodiments, the second portion 121 includes a loop or a series of (e.g., concentric) loops around an axis, such as... Figure 1 Rings 122A-D in the middle. (Although in Figure 1 Only four rings are shown, but the grid 120 may include any suitable number of rings. In some embodiments, the second portion 121 surrounds the ion collector 110. In some embodiments, the ion collector 110 is positioned on an axis passing through the center of the second portion 121. In some embodiments, the ion collector 110 is positioned through... Figure 1 The ion collector 110 is positioned on the axis at the center of each of a series of concentric rings 122A-D. In other embodiments, the ion collector 110 is arranged through... Figure 2 On the axis at the center of coil 222. The first part 123 of grid 120 connects the second part 121 of grid 120 to generator 140 and extends through panel 130.

[0034] In some embodiments, the grid 220 includes a second portion 221, which includes coils, for example... Figure 2 The coil 222 shown.

[0035] In some embodiments, generator 140 is configured to apply a voltage bias to grid 120. In some embodiments, generator 140 is configured to generate at least one of AC voltage, positive DC voltage, or negative DC voltage to grid 120. In some embodiments, generator 140 is configured to (e.g., periodically or manually) change the type of the generated voltage (i.e., from DC voltage to AC voltage and vice versa). In some embodiments, generator 140 is configured to (e.g., periodically, continuously, or manually) change the amount and / or sign of the generated voltage. In some embodiments, controller 160 is configured to control the amount, sign, type, and / or duration of the voltage generated by generator 140. In some embodiments, controller 160 is configured to control the amount, sign, type, and / or duration of the voltage generated by generator 140 based on the output of meter 150 or from user input. In some embodiments, the positive DC voltage is between about 1V and about 50V, or between about 5V and about 25V, or between about 10V and about 20V. In some embodiments, the negative DC voltage is between about -1V and about -50V, or between about -5V and about -25V, or between about -10V and about -20V. In some embodiments, the AC voltage is between about 5V and about 110V, or between about 20V and about 80V, or between about 30V and about 60V. In some embodiments, the AC voltage has a frequency of about 30Hz to about 100Hz, or between about 50Hz and 60Hz.

[0036] When generator 140 provides a voltage bias to grid 120, a potential gradient (e.g., relative) is generated between grid 120 and ion collector 110. Depending on the type of ions and the sign of the voltage bias, ions are either repelled or attracted to ion collector 110. For example, when a positive voltage bias is applied to grid 120, the potential gradient between grid 120 and ion collector 110 will attract positive ions and repel negative ions to ion collector 110. Similarly, when a negative voltage bias is applied to grid 120, the potential gradient between grid 120 and ion collector 110 will attract negative ions and repel positive ions to ion collector 110. In some embodiments, grid 120 may be configured to direct ions to ion collector 110 when a voltage is applied to grid 120. In some embodiments, grid 120 may be configured to trap ions inside coil 222 or concentric rings 122A-D when a voltage is applied to grid 120. In some embodiments, the grid 120 is configured to capture positive ions and / or direct positive ions to the ion collector 110 when a positive DC voltage is applied to the grid 120. In some embodiments, the grid 120 is configured to capture negative ions and direct negative ions to the ion collector 110 when a negative DC voltage is applied to the grid 120. In some embodiments, the grid 120 is configured to capture both positive and negative ions and direct them to the ion collector 110 when an AC voltage is applied to the grid 120.

[0037] In some embodiments, device 100 further includes a modulator 170. In some embodiments, modulator 170 includes one or more wires. In some embodiments, modulator includes a conductive material, such as a metal. In some embodiments, modulator 170 extends through panel 130 and is connected to switch 180. In some embodiments, switch 180 is configured to be grounded or connected to a first portion 123 of grid 120 and generator 140. In some embodiments, when switch 180 is grounded, modulator is not (e.g., directly) connected to grid 120. In some embodiments, modulator is not (e.g., directly) connected to a second portion 121 (or 221) of grid 120. In some embodiments, device 100 is configured to modulate the strength and / or shape of a potential gradient based on the state of switch 180. When switch is connected to the first portion 123 of grid 120, generator 140 applies a voltage bias to modulator 170. When switch is grounded, no voltage bias is applied to modulator 170. In some embodiments, switch 180 is connected to controller 160. In some embodiments, controller 160 is configured to change the state of switch 180 based on user input, the output of meter 150, or signals generated by controller 160 and / or signals received from user input. In some embodiments, controller 160 is configured to change the state of switch 180 when the output from meter 150 exceeds a threshold.

[0038] Figure 3 A reactor system 300 for detecting parasitic plasma according to an exemplary embodiment of the present disclosure is shown. The reactor system 300 includes a reaction chamber 305, a base 330 configured to hold a substrate 320, a shaft 340 supporting the base 330, an upper electrode 335, a reaction space 310, a sub-space 350, a detection device 360 ​​including a meter 370, and a controller 380.

[0039] Reaction chamber 305 may include any suitable reaction chamber, such as an atomic layer deposition (ALD) or chemical vapor deposition (CVD) reaction chamber. For example, reaction chamber 305 may form part of a capacitively coupled plasma-enhanced reactor system.

[0040] The detection device 360 ​​can be any detection device as described herein. The detection device 360 ​​is configured to detect ions, such as ions generated by parasitic plasma. In some embodiments, the reactor system 300 includes multiple detection devices. In some embodiments, the multiple detection devices are placed in the same space, such as subspace 350. In some embodiments, the reactor system is configured to detect parasitic plasma in multiple spaces, and the detection devices are placed in multiple spaces, such as in exhaust space 390.

[0041] In some embodiments, the base 330 may include a lower electrode. In some embodiments, the reaction space 310 is defined at least partially by the top surface of the base 330. In some embodiments, the reaction space 310 is defined at least partially by the lower surface of the upper electrode 335. During operation of the reactor system 300, plasma may be generated in the reaction space 310, for example by applying plasma (e.g., RF) power to one or more of the base 330 and the upper electrode 335.

[0042] In some embodiments, the reactor system 300 includes a subspace 350 adjacent to the reaction space 310. In some embodiments, the subspace 350 is at least partially defined by or disposed below the lower surface of the base 330. Parasitic plasma can be generated in the subspace 350 when plasma (e.g., RF) power is applied to the base 330 and / or the upper electrode 335, or when plasma is generated in the reaction space 310.

[0043] In some embodiments, the detection device 360 ​​is disposed in the subspace 350. In some embodiments, the detection device 360 ​​includes a panel connected to a wall in the subspace 350. In some embodiments, the panel of the detection device 360 ​​is sealed (e.g., vacuum-sealed or near-vacuum-sealed) to the wall in the subspace 350. In some embodiments, the detection device 360 ​​includes an ion collector extending into the subspace 350. In some embodiments, the detection device 360 ​​includes or is connected to a meter 370. The meter 370 may be the same as or similar to the meter described above. In some embodiments, the meter 370 is an electrometer. In some embodiments, the meter 370 is configured to measure a change in one or more of current, charge, or potential difference when ions contact the ion collector of the detection device 360. In some embodiments, the meter 370 generates an output (e.g., to a controller 380) representing a change in current, potential, or charge. Thus, the output may indicate the presence of ions, such as ions generated by plasma. In some embodiments, the meter 370 is configured to measure positive changes in charge or potential and / or negative changes in charge or potential.

[0044] In some embodiments, the detection device 360 ​​is connected to the controller 380. In some embodiments, the controller 380 may be the same as or similar to the controller described above. In other embodiments, the controller 380 may include additional hardware, software, and connections to control components of the reactor system 300. In some embodiments, the controller 380 may include modules, such as software or hardware components, such as an FPGA or ASIC, that perform certain tasks. Modules may be advantageously configured to reside on an addressable storage medium of the control system and configured to perform one or more processes or methods as described herein. In some embodiments, the controller 380 includes electronic circuitry and software to perform one or more of the following: selectively operating one or more generators, meters, and / or switches in the detection device; collecting, storing, and analyzing outputs from the meter 370; generating one or more signals based on the outputs from the meter 370 (e.g., to other components of the reactor system or to a user interface); and selectively operating other components included in the reactor system 300. In some embodiments, the controller 380 is a component of the detection device 360. In some embodiments, the controller 380 is a component separate from the detection device 360. In some embodiments, the reactor system 300 may include multiple controllers. Each of the plurality of controllers may perform one or more functions of controller 380 as described herein. In some embodiments, controller 380 may be configured to perform sub-steps of the methods described herein.

[0045] In some embodiments, controller 380 is configured to generate one or more signals based on the output from meter 370. In some embodiments, controller 380 is configured to generate a first signal indicating whether a change in current, potential, or charge exceeds a first threshold. In some embodiments, controller 380 is configured to generate a second signal indicating whether a change in current, potential, or charge exceeds a second threshold within a first time period. In some embodiments, the duration of the first time period is between about 0.5 seconds and about 30 seconds, or between about 1 second and about 15 seconds, or between about 3 seconds and about 10 seconds. In some embodiments, controller 380 is configured to generate a third signal indicating the ion collection rate (and therefore the rate at which ions are generated from the plasma). In some embodiments, controller 380 is configured to send one or more of the first, second, or third signals to other components, such as other system components, or to a user interface. In some embodiments, controller 380 is configured to send a signal to interlock or stop plasma generation (e.g., by stopping the supply of RF power to one or more electrodes) if the signal exceeds the threshold. In some embodiments, controller 380 is configured to send a signal to shut down the base heater, shut down the gas flow, or stop the supply of plasma power. In some embodiments, controller is configured to receive outputs from multiple detection devices. In some embodiments, the controller is configured to send a signal to interlock or stop plasma generation if the output from more than one detection device exceeds a first threshold and / or exceeds a second threshold within a first time period.

[0046] Other configurations of the reactor system 300 are possible, including different configurations of the reaction space, electrodes, chambers, exhaust systems, etc. Furthermore, for the sake of simplicity and to illustrate the system, many components have been omitted, and these components may include, for example, various valves, manifolds, purifiers, heaters, containers, vents, and / or bypasses.

[0047] During operation of reactor system 300, substrate 320, such as a semiconductor wafer, is transferred from, for example, substrate processing system to reaction chamber 305. Once the substrate is transferred to reaction chamber 305, one or more gases from a gas source (not shown) can be introduced into reaction chamber 305.

[0048] Figure 4 A method 400 for detecting parasitic plasma in a reactor system according to an exemplary embodiment of the present disclosure is shown. Method 400 includes providing a reactor system 410, providing a detection device 420, generating plasma 430, operating the detection device 440, and optionally stopping plasma generation 450 if parasitic plasma is detected.

[0049] The reactor system provided during step 410 is configured to generate plasma and can be any reactor system as described herein. The reactor system includes a reaction space and a sub-space. In some embodiments, the reactor system is configured to generate plasma in the reaction space. In some embodiments, the reactor system is designed not to generate parasitic plasma in the sub-space when operating as intended.

[0050] Method 400 continues by providing a detection device 420. In some embodiments, providing the detection device 420 includes providing the detection device in a secondary space. In some embodiments, providing the detection device 420 includes providing the detection device in another space (e.g., an exhaust system) where plasma is to be detected. In some embodiments, multiple detection devices are provided in one or more spaces. In some embodiments, the detection device is positioned within the line of sight of the space where plasma can be detected. In some embodiments, there may be no solid material between the detection device and the space where the plasma is to be detected. The detection device is any suitable detection device as described herein. In some embodiments, the detection device is configured to detect ions. In some embodiments, the detection device includes an ion collector and is configured to measure a change in one or more of current, charge, or potential difference when ions contact the ion collector.

[0051] Method 400 continues to generate plasma 430. In some embodiments, generating plasma 430 includes providing RF power to one or more electrodes and providing one or more gases to the reaction space in the reactor system. As described above, the reactor system may be designed to generate plasma in the reaction space but not in the subspace when operating as intended. However, the reactor system may be able to generate parasitic plasma in the subspace while simultaneously generating plasma in the reaction space. In some embodiments, generating plasma 430 includes generating parasitic plasma in the subspace. Generating plasma 430 includes generating ions that can travel in the reaction space and / or the subspace. In some embodiments, generating parasitic plasma in the subspace causes ions to damage components of the reactor system.

[0052] Method 400 continues to operate the detection device 440. In some embodiments, operating the detection device 440 includes measuring one or more of current, charge, or potential difference when ions contact the ion collector. In some embodiments, operating the detection device 440 includes generating an output indicating a change in one or more of current, charge, or potential difference from a meter (e.g., to a controller). In some embodiments, operating the detection device 440 includes a controller collecting, storing, and / or analyzing the output from the meter. In some embodiments, operating the detection device 440 includes a controller generating one or more signals based on the output from the meter. In some embodiments, operating the detection device 440 includes a controller generating a first signal indicating whether a change in current, potential, or charge exceeds a first threshold. The first threshold may be an input from a user, a predetermined value, or a calculated value from other inputs, such as the amount of plasma (e.g., RF power) supplied to the electrode. In some embodiments, operating the detection device 440 includes a controller generating a second signal indicating whether a change in current, potential, or charge exceeds a second threshold within a first time period. The second threshold may be an input from a user, a predetermined value, or a calculated value from other inputs, such as the amount of RF power supplied to the electrode. The first time period can be an input from the user, a predetermined value, or a calculated value from other inputs, such as the amount of RF power supplied to the electrodes. In some embodiments, the first time period is at least 0.5 seconds. In some embodiments, the duration of the first time period is between about 0.5 seconds and about 30 seconds, or between about 1 second and about 15 seconds, or between about 3 seconds and about 10 seconds. In some embodiments, the operation detection device 440 includes a controller generating a third signal indicating the ion collection rate (and therefore the rate at which ions are generated from the plasma). In some embodiments, the operation detection device 440 includes a controller sending one or more of the first, second, or third signals to other components, such as other system components, or to a user interface. In some embodiments, the operation detection device includes determining whether parasitic plasma is generated based on one or more signals from the controller.

[0053] In some embodiments, the operation detection device 440 includes a generator of the detection device applying at least one of an AC voltage, a positive DC voltage, or a negative DC voltage to the grid of the detection device. In some embodiments, the operation detection device 440 includes modifying the voltage applied to the grid. In some embodiments, the positive DC voltage is between about 1V and about 50V, or between about 5V and about 25V, or between about 10V and about 20V. In some embodiments, the negative DC voltage is between about -1V and about -50V, or between about -5V and about -25V, or between about -10V and about -20V. In some embodiments, the AC voltage is between about 5V and about 110V, or between about 20V and about 80V, or between about 30V and about 60V. In some embodiments, the AC voltage has a frequency of about 30Hz to about 100Hz or between about 50Hz and 60Hz.

[0054] In some embodiments, the operation detection device 440 includes changing the state of a switch of the detection device, wherein the switch is connected to a modulator and ground or connected to a grid. In some embodiments, the operation detection device 440 includes a controller that changes the state of the switch based on a signal from a controller.

[0055] If parasitic plasma 450 is detected, method 400 may optionally continue to stop plasma generation. In some embodiments, stopping plasma generation 450 includes interlocking the reactor system. In some embodiments, stopping plasma generation 450 includes stopping the supply of RF power to the reactor system. A controller may be used to interlock the reactor system or control the supply of RF power.

[0056] The exemplary embodiments described above do not limit the scope of the invention, as these embodiments are merely examples of embodiments of the invention, the scope of which is defined by the appended claims and their legal equivalents. Any equivalent embodiments are intended to fall within the scope of the invention. In fact, various modifications to this disclosure, such as alternative useful combinations of the described elements, in addition to those shown and described herein, will become apparent to those skilled in the art from the description. These modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

1. A method for detecting parasitic plasma in a reactor system, the method comprising: A reactor system is provided, which includes a reaction space and a secondary space adjacent to the reaction space; Provide detection devices in the secondary space; Plasma is generated in the reaction space; as well as A signal indicating the presence of parasitic plasma in the subspace is generated from a detection device, wherein the detection device is configured to detect ions.

2. The method according to claim 1, wherein, The detection device includes: An ion collector that extends into the subspace; A panel, wherein an ion collector extends through the panel, and wherein the panel is configured to be attached to the wall of the sub-space; and A meter configured to measure at least one of current, charge, or potential difference, wherein the meter is connected to an ion collector, and The detection device is configured to measure changes in one or more of current, charge, or potential difference when ions come into contact with the ion collector.

3. The method according to claim 2, wherein, The detection device further includes: A grid comprising a first portion extending through the panel and a second portion comprising coils or a series of concentric rings, wherein the second portion surrounds the ion collector; and A generator connected to a grid, wherein the generator is configured to produce at least one of an AC voltage, a positive DC voltage, or a negative DC voltage to the grid.

4. The method of claim 3, further comprising applying at least one of the AC voltage, the positive DC voltage, or the negative DC voltage to the grid. in, The grid is configured to capture ions and guide them to the ion collector when a voltage is applied to the grid.

5. The method according to claim 4, wherein, At least one of the AC voltage or the negative DC voltage is applied to the grid.

6. The method according to claim 1, wherein, The top surface of the base at least partially defines the reaction space, and the subspace is disposed below the base.

7. The method according to claim 1, wherein, If a change in one or more of the current, charge, or potential difference exceeds a first threshold, the detection device generates a first signal indicating the presence of the parasitic plasma.

8. The method according to claim 1, wherein, If the change in one or more of the current, charge, or potential difference exceeds a second threshold within a first time period, the detection device generates a second signal indicating the presence of the parasitic plasma.

9. The method according to claim 1, wherein, The detection device is connected to a controller, wherein the controller is configured to stop generating the plasma in the reaction space if a change in one or more of the current, charge, or potential difference exceeds a first threshold.

10. The method according to claim 3, wherein, The detection device further includes a modulator extending through the panel and connected to the switch, and wherein the detection device is connected to a controller, wherein the controller is configured to change the state of the switch if a change in one or more of the current, charge, or potential difference exceeds a second threshold.

11. The method of claim 1, further comprising providing a plurality of detection devices in the subspace.

12. A reactor system with parasitic plasma detection, the reactor system comprising: Reaction chamber; The base is located in the reaction chamber; The reaction space, wherein the reaction space is at least partially defined by the top surface of the base; Subspace, which is located below the base; and A detection device mounted to a wall in a subspace, wherein the detection device is configured to detect parasitic plasma in the subspace, wherein the detection device includes an ion collector extending into the subspace, and wherein the detection device is configured to measure a change in one or more of current, charge, or potential difference when ions contact the ion collector.

13. The reactor system according to claim 12, wherein, The detection device further includes: A panel connected to the wall, wherein the panel is sealed to the wall, and wherein the ion collector extends through the panel; and A meter configured to measure at least one of current, charge, or potential difference, wherein the meter is connected to an ion collector.

14. The reactor system according to claim 13, wherein, The detection device further includes: A grid comprising a first portion extending through the panel and a second portion comprising coils or a series of concentric rings, wherein the second portion surrounds the ion collector; and A generator connected to a grid, wherein the generator is configured to produce at least one of an AC voltage, a positive DC voltage, or a negative DC voltage to the grid.

15. The reactor system of claim 12, further comprising a controller connected to the detection device, wherein, The controller is configured to interlock the reactor system if the signal from the detection device exceeds a threshold.

16. An apparatus for detecting plasma, the apparatus comprising: panel; An ion collector comprising a conductive material, wherein the ion collector extends through a panel; A grid comprising a first portion extending through a panel and a second portion comprising a coil or a series of concentric rings, wherein the second portion surrounds an ion collector; A meter configured to measure at least one of current, charge, or potential difference, wherein the meter is connected to an ion collector; and A generator connected to a grid, wherein the generator is configured to produce at least one of an AC voltage, a positive DC voltage, or a negative DC voltage to the grid. The device is configured to detect ions generated from plasma.

17. The apparatus according to claim 16, wherein, The ion collector is positioned along an axis passing through the center of each of the series of concentric rings or the center of the coil.

18. The apparatus of claim 16, further comprising a controller configured to convert the output from the meter into a signal indicating the presence of the plasma.

19. The apparatus according to claim 16, wherein, The generator is configured to produce at least one of the AC voltage or the negative DC voltage to the grid.

20. The apparatus of claim 16, further comprising a modulator extending through the panel and connected to a switch.

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