2533 results about "Plasma processing" patented technology

A system includes a processing chamber configured to perform a plasma process with respect to one or more substrates. The system further includes an electrostatic chuck disposed within the processing chamber. The electrostatic chuck includes one or more electrodes. The system further includes an analog filter electrically coupled to at least one electrode of the one or more electrodes. The analog filter includes an air-core coil including a first coil and a second coil disposed within the first coil. The first coil and the second coil together form an inductor.

Embodiments provided herein generally include apparatus, plasma processing systems and methods for tuning in a radio frequency (RF) plasma processing system for improving substrate processing metrics. Some embodiments are directed to an apparatus for processing a substrate in a plasma processing system. The apparatus generally includes: an impedance for a match circuit configured to perform impedance matching for a plasma load; a diode-based switch coupled to the impedance for the match circuit; at least one signal generator coupled to the diode-based switch and configured to bias the diode-based switch to a first position based on a first impedance generated in the plasma load; and a second position based on a second impedance generated in the plasma load and an RF signal generator configured to provide an RF signal to the plasma load.

The invention discloses a carbon fiber composite material surface modification spraying system and a control method thereof. The system comprises a multi-axis robot, a plasma spray gun, a contact angle measuring probe, a 3D line laser scanner, a hyperspectral imager, an environment sensor and a controller. According to the method, the plasma power and the robot speed are adjusted in real time through contact angle measurement and plasma treatment feedback control, so that the CFRP surface can accurately reach a target value, and the coating adhesive force is improved; 3D line laser scanning and hyperspectral imaging are combined, and the posture, the distance, the wet film thickness and the component uniformity of the spray gun are monitored in real time; based on a prediction model fusing a physical model and a neural network, a self-adaptive fuzzy PID control algorithm is adopted, and the coating flow and the track posture of a spray gun are accurately regulated and controlled in real time. The problems of weak coating binding force, uneven thickness, orange peel, sagging and serious coating waste in traditional spraying are effectively solved, and self-adaptive, high-quality and green spraying of workpieces with complex curved surfaces is achieved.

A plasma processing system includes a pulsed voltage source configured to generate a pulsed voltage waveform having a first frequency. The plasma processing system includes a radio frequency source configured to generate a radio frequency waveform having a second frequency that is higher than the first frequency. The plasma processing system includes a junction box enclosure electrically coupling the pulsed voltage source to a direct current conductor coupled to a substrate support and further electrically coupling the pulsed voltage source to a radio frequency conductor coupled to a radio frequency baseplate. The junction box enclosure includes a pulsed voltage filter circuit coupled between the radio frequency source and the radio frequency conductor and operable to filter the pulsed voltage waveform. The junction box enclosure further includes a radio frequency filter circuit coupled between the pulsed voltage source and the direct current conductor and operable to filter the radio frequency waveform.

Embodiments of the disclosure include apparatus (e.g., plasma processing systems) and methods for the plasma processing of a substrate in a processing chamber. Some embodiments are directed to a method for waveform generation, which generally includes delivering a radio frequency (RF) waveform at a frequency for a first period of time using a RF generator and then halting the delivery of the RF waveform for a second period of time, and delivering a pulsed voltage waveform at a first voltage for at least a portion of a third period of time using a pulser, wherein the delivery of the pulsed voltage waveform overlaps with the delivery of the RF waveform during a portion of the second period of time.

The invention discloses a microporous diaphragm for a low-electrical-impedance lithium battery and a preparation method of the microporous diaphragm. The diaphragm comprises: a base film layer, wherein the base film layer is of a microporous structure formed by biaxially stretching polypropylene and / or polyethylene; the surface of the base film layer is coated with the functional coating, and the functional coating contains mixed slurry of inorganic nanoparticles and a binder; the surface modification layer is formed by introducing a hydrophilic electrolyte group on the surface of the functional coating through plasma treatment or chemical grafting. The base membrane layer forms a uniform micropore structure through a two-way stretching process, the functional coating is formed by compounding nano silicon dioxide or aluminum oxide and polyvinylidene fluoride according to a specific proportion, a porous layer with gradient pore diameter is formed, the pore size of the porous layer is smaller than that of the base membrane layer, and efficient permeation of electrolyte is ensured. Electrolyte-philic groups such as sulfonic groups are introduced into the surface modification layer, so that the wettability of the diaphragm to an electrolyte is remarkably improved. During preparation, the base membrane is formed through melt blending, two-way stretching and pore-forming agent extraction, and then the functional layer is constructed through slurry coating and a low-temperature plasma treatment or sulfonation process. The diaphragm combines gradient aperture design, inorganic filler enhancement and surface chemical modification, and realizes low impedance, high thermal stability and excellent mechanical strength.

The invention relates to the technical field of wafer processing, in particular to a reaction chamber and plasma processing equipment, which comprises a quartz tube, an induction coil, a Faraday shield cage, a state monitoring device, a rotation driving device and a control unit, and is characterized in that the quartz tube is arranged at the top of a processing chamber; the induction coil is arranged around the outer side of the quartz tube; the Faraday shielding cage is provided with a slit, and the orthographic projection of the slit on the circumferential wall of the quartz tube forms an erosion area; the state monitoring device is used for monitoring the erosion area; the driving end of the rotary driving device is connected with the quartz tube or the Faraday shielding cage; the control unit is in communication connection with the state monitoring device and the rotary driving device; according to the invention, through real-time monitoring and an active regulation and control mechanism, the problem of concentrated erosion of plasma to the quartz tube in a high-hydrogen process is effectively solved.

The invention provides a surface modified carbon fiber as well as a preparation method and application thereof, and belongs to the technical field of battery materials. Physical or chemical treatment on the surface of the carbon fiber is realized by performing one or more of accurate plasma treatment, chemical etching, coupling agent treatment and nano particle deposition on the surface of the carbon fiber, so that functional groups are introduced or a rough nano structure is formed; a functional layer with a specific functional group and a rough structure which are beneficial to attachment of positive electrode material slurry are formed on the surface of the carbon fiber, and then a stable and well-attached surface modified layer is obtained through heat treatment, so that the surface modified carbon fiber is prepared. According to the method disclosed by the invention, the surface roughness and the functional group richness can be improved on the premise that the mechanical property of the fiber is not obviously damaged, so that the adhesiveness and the electrical property of the positive electrode material slurry are enhanced, and a foundation is laid for the preparation of a carbon fiber positive electrode material and a structure-energy storage integrated composite structure.

The invention relates to the technical field of wafer processing equipment, in particular to a reaction cavity for a high-hydrogen process and plasma processing equipment, and the reaction cavity comprises a quartz tube; the first coil surrounds the outer side of the quartz tube and is connected with an external radio frequency power supply; the Faraday shielding cage is annularly arranged outside the quartz tube and between the quartz tube and the first coil, and a plurality of slits which penetrate through the side wall of the Faraday shielding cage and extend in the axial direction are formed in the Faraday shielding cage; the blocking piece is arranged in the quartz tube, and a structure formed by orthographic projection of the blocking piece on the circumferential side wall of the Faraday shielding cage covers a structure formed by orthographic projection of the first coil on the circumferential side wall of the Faraday shielding cage; the blocking piece is arranged in the quartz tube, so that concentrated bombardment of plasma generated in the high-hydrogen process on the inner wall of the quartz tube can be effectively blocked, the problems of erosion of the quartz tube and particle stripping are remarkably relieved, the process yield of plasma processing equipment is increased, and the service life of a machine table is prolonged.

The invention relates to the technical field of electrochromism coating, in particular to an electrochromism device coating process and method, and the electrochromism device coating process comprises the following steps: step 1, substrate pretreatment: cleaning attachments on the surface of a flexible substrate through ultrasonic cleaning and plasma treatment; step 2, conducting layer deposition treatment: depositing an indium tin oxide (ITO) conducting layer on the substrate at the deposition temperature of 100-380 DEG C, the thickness of 200-350 nm and the vacuum degree of less than or equal to 10 <-5 > Pa; step 3, electrochromic layer deposition treatment: sequentially depositing a tungsten oxide (WO3) layer and a nickel oxide (NiO) layer through a magnetron sputtering process, and controlling the film thickness ratio of NiO to WO3 to enable the ratio of NiO / W to be 0.25-0.357; 4, annealing treatment is conducted, specifically, annealing is conducted for the first time at the temperature of 200-500 DEG C, and the annealing time is 200-300 seconds; and secondary annealing is conducted, specifically, annealing is conducted at the temperature of 400 DEG C, and the annealing time ranges from 200 seconds to 800 seconds. The effect of improving the yellow ground color of the electrochromic device is achieved.

The invention relates to the technical field of wafer processing equipment, in particular to a reaction cavity and plasma processing equipment, comprising a quartz tube, an induction coil and a shielding member, the quartz tube is arranged at the top of a processing chamber; the induction coil is arranged on the outer side of the quartz tube in a surrounding manner and comprises a plurality of annular sections which are arranged at intervals in the axial direction of the quartz tube and a plurality of connecting sections which are arranged between every two adjacent annular sections and are used for connecting every two adjacent annular sections; the shielding component is annularly arranged between the quartz tube and the induction coil and comprises a plurality of annular shielding parts arranged in the axial direction of the quartz tube and a plurality of arc-shaped shielding parts arranged between every two adjacent annular shielding parts and used for connecting every two adjacent annular shielding parts; a slit is formed between two adjacent annular shielding parts; concentrated bombardment of high-energy ions on the inner wall of the quartz tube can be obviously prevented, so that erosion of the quartz tube is effectively reduced, particulate matter is reduced, the service life of a machine is prolonged, and the process yield is increased.

A substrate processing system comprising: a plasma processing apparatus; a depressurization transfer device having a transfer robot and an edge ring; and a controller is disclosed. The plasma processing apparatus includes: a depressurizable processing chamber; a substrate support table; a lifting mechanism; a gas supply part; and a plasma generating part. The controller controls following steps to be performed in following order: (a) performing plasma processing on the substrate and, then, applying a voltage of a first polarity to the electrode; (b) neutralizing the edge ring, by applying a voltage of a second polarity to the electrode while supplying a gas, and stopping the application of the voltage to the electrode after a predetermined period of time elapses; (c) separating the edge ring from a ring placing surface of the substrate support table; and (d) transferring the edge ring from the processing chamber to the depressurization pressure transfer device.

The invention relates to the technical field of semiconductor manufacturing equipment, in particular to a process cavity with a controllable gas flow field and plasma processing equipment, and the process cavity comprises a cavity body which is provided with a cavity for bearing a wafer; the air inlet channel is communicated with the cavity; the main air exhaust channel is arranged at the bottom of the cavity body and is communicated with the cavity; the main air exhaust channel is connected with a main control valve; the auxiliary air exhaust channel is arranged on the side wall of the cavity body and is communicated with the cavity; the main control valve and the auxiliary control valve work cooperatively. The control device is in communication connection with the main control valve and the auxiliary control valve; through the cooperation of the auxiliary air exhaust channel and the auxiliary control valve and the cooperation of the main air exhaust channel and the main control valve, the flow field distribution in the process cavity is adjusted, the gas concentration gradient and the edge dead zone in the radial direction of the wafer are guided to be eliminated, and the consistency of the side face angle, the surface roughness center area and the edge area of the outer ring groove or hole of the wafer is achieved.

The invention discloses a ceramic rock plate with a decorative effect and a production process thereof, and belongs to the technical field of ceramics. The rock plate is composed of a green body layer, a ground glaze layer, a cover glaze layer and an ink jet pattern layer, and after firing, a micro-nano rough and low-surface-energy synergistic protection layer is formed through oxygen-nitrogen plasma activation, a hydrothermal reaction of aluminum salt and an ammonia source compound, high-temperature calcination and silane derivative dipping and curing. The green body takes wollastonite, quartz sand and the like as raw materials, and the ground glaze and the cover glaze adopt a feldspar-quartz-nepheline system; after firing, performing plasma treatment and hydrothermal treatment to generate needle-shaped aluminum oxide, and introducing a silane derivative to realize double functions of super-hydrophobicity and wear resistance. Compared with the prior art, the anti-fouling and wear-resistant coating reaches the national standard 5 level, the process is simple, and the coating can be directly connected to an existing production line and is suitable for high-end wall floor decoration.

The invention relates to the technical field of preparation of medical supplies, in particular to a surgical membrane and a preparation process. During specific use, firstly, a polyurethane base membrane is selected and subjected to plasma treatment; spraying a nano SiO2 dispersion liquid containing a photoinitiator on the surface of the treated polyurethane base film, and then performing ultraviolet patterning irradiation to form a micro-bulge structure to obtain a base material layer; projecting the colloidal fluid to a temperature gradient mask through a digital micromirror device, so that the colloidal fluid is subjected to regional thermal polymerization on the substrate layer to form an intelligent adhesive layer with viscosity gradient; by adopting an aerosol jet printing technology, super absorbent fibers and polyvinyl alcohol-borax dynamic crosslinking hydrogel are co-deposited to form a drainage layer, so that the technical problems that a surgical membrane prepared by a surgical membrane preparation mode in the prior art is inflexible in adhesion and poor in surface structure performance, and a preparation process is difficult to accurately control are solved.

The invention discloses a multi-mode magnetic field intelligent closed-loop plasma confinement system and method. The system comprises a multi-mode magnetic field generation module, a multi-dimensional plasma diagnosis module and a layered intelligent closed-loop control module. The multi-mode magnetic field generation module generates a steady-state, pulse and alternating composite magnetic field to realize adjustable space gradient; the multi-dimensional diagnosis module synchronously acquires electrical, optical and particle parameters, and ensures the accuracy through data fusion; and the hierarchical intelligent closed-loop control module generates an adjusting instruction to realize closed-loop optimization based on dynamic threshold and multi-algorithm scheduling. According to the method, the constraint performance is improved through the steps of initialization, data acquisition, state evaluation and closed-loop adjustment in combination with parameter self-optimization and three-level fault protection. According to the scheme, the plasma constraint time exceeds 300 s, the escape rate is lower than 5%, the adjustment response is smaller than or equal to 10 ms, the method adapts to multiple working conditions and can be popularized to the fields of nuclear fusion experiments and plasma processing, and the problems that a traditional system is poor in stability and lags in response are solved.

The invention discloses a selective ink transfer printing method based on a liquid-like surface. The selective ink transfer printing method comprises the following steps that 1, the surface of a base body is treated through oxygen plasma; step 2, dissolving a reaction monomer in methylbenzene containing saturated water; step 3, placing the substrate subjected to oxygen plasma treatment in the reaction solution in the step 2 to form a PDMS molecular brush; step 4, performing pattern design on the surface of the PDMS molecular brush by adopting a mask process, treating by using an alkali solution, selectively removing the molecular brush in an unprotected area, and restoring the molecular brush to a hydrophilic glass surface; step 5, coating oil-based ink on the surface treated in the step 4 to form a clear pattern; and step 6, enabling the surface of the printing ink with the pattern to be in direct contact with a target substrate, and applying pressure to transfer the printing ink. According to the method, the problems of resolution, ink diffusion control and pattern uniformity of the existing printing technology are solved, and the printing precision and applicability are improved.

The invention belongs to the technical field of inorganic powder material modification, and discloses an aluminum hydroxide powder modification treatment method which comprises the following steps: step 1, plasma pretreatment, step 2, in-situ coordination reaction, step 3, nano-composite coating and step 4, post-treatment. The performance of aluminum hydroxide is remarkably improved through a plasma pretreatment-in-situ coordination-nano coating synergistic process, specifically, surface hydroxyl groups are reduced by 45% through plasma treatment, and a contact angle is larger than or equal to 120 degrees, the thermal decomposition temperature is increased by 55 DEG C, and LOI is increased to 31.8% by combining Al-O-P bonding and a SiO-GQDs composite coating layer. According to the process, the energy consumption of the pulse plasma is reduced by 40%, the cost of the spray drying coating process is reduced by 60%, and the GQDs are derived from the graphite waste, so that resource circulation is realized; and the material is non-toxic, has no stripping on a cold-hot cycle interface, meets the green flame-retardant standard, and provides an efficient solution for sustainable development of inorganic fillers.

A method for generating a bias voltage includes generating a radio frequency (RF) sinusoidal wave voltage, generating a DC square wave voltage, and forming a bias waveform by synchronizing the RF sinusoidal wave voltage and the DC square wave voltage. The method further includes providing the bias waveform to an electrode of a plasma processing system.

The invention discloses an instrument capable of being separated through light control and a preparation method and application of the instrument, and belongs to the technical field of biomedical engineering and flexible electronics. The instrument capable of being separated through light control comprises a flexible substrate layer, an electrode layer and a gel integration layer, the preparation method comprises the following steps: (1) forming an electrode pattern on a silicon wafer through photoetching, and carrying out oxygen plasma treatment to prepare a hydrophilic surface; (2) spin-coating a water-soluble polymer solution to form a sacrificial layer; (3) spin-coating silicone rubber pre-polymerized liquid and curing to form a flexible substrate layer; (4) dissolving the sacrificial layer with water to realize demolding, and embedding a patterned conductive material into the surface to form an electrode layer; and (5) coating the photo-responsive adhesive hydrogel pre-polymerization liquid, and performing cross-linking curing to form a gel integration layer, thereby obtaining the photo-responsive adhesive hydrogel. Through integrated structural design and functional material integration, the brain-computer interface ECoG electrode with high flexibility, high adhesion, high conductivity and controllable debonding capacity and the like is provided, and a technical basis and an application platform are provided for a next-generation intelligent implantable brain-computer system.

The invention discloses a method for preparing a carbon nanotube through plasma pretreatment-dipping deposition, which comprises the following steps: carrying out plasma treatment on a substrate, dipping the substrate subjected to plasma treatment into a catalyst precursor solution, taking out and drying to obtain a pretreated substrate; and introducing a carbon source gas, and preparing the carbon nanotubes on the surface of the pretreated substrate by adopting a vapor deposition method. According to the method, the wettability of the catalyst solution is improved by processing the base material through the plasma, the surface of the base plate is rough, the migration potential barrier of catalyst atoms on the surface of the base plate in the high-temperature annealing process is increased, excessive agglomeration of the catalyst atoms is prevented, and formation of small catalyst particles which are uniformly distributed is promoted; therefore, the prepared carbon nano tube is relatively compact, and the obtained carbon nano tube is high in density, large in specific surface area, and relatively high in yield and purity.

This plasma processing device has a processing chamber, a substrate holding unit, and a plasma source. The processing chamber provides a processing space for a substrate. The substrate holding unit holds the substrate in the processing chamber. The plasma source is configured to supply plasma into the processing chamber and comprises a gas supply unit, piping, an electromagnetic wave generator, an electromagnetic wave supply unit, and a resonator array structure. The gas supply unit supplies a raw material gas. The piping connects the gas supply unit and the processing chamber. The electromagnetic wave generator generates electromagnetic waves for plasma excitation to be supplied into the piping. The electromagnetic wave supply unit supplies the electromagnetic waves into the piping via a dielectric window provided in the piping. The resonator array structure includes a plurality of resonators that can resonate with a magnetic field component of the electromagnetic waves, have a smaller size than the wavelength of the electromagnetic waves, and are disposed in the direction of the same plane surface.

A control method of a plasma processing apparatus including a first electrode that places a workpiece thereon includes supplying a bias power to the first electrode, and supplying a source power having a frequency higher than that of the bias power into a plasma processing space. The source power has a first state and a second state. The control method further includes a first control process of alternately applying the first state and the second state of the source power in synchronization with a signal synchronized with a cycle of a radio frequency of the bias power, or a phase within one cycle of a reference electrical state that represents any one of a voltage, current, and electromagnetic field measured in a power feeding system of the bias power.

The invention discloses a paper-based composite film, which adopts a four-layer structural design, and the outer layer is an ultraviolet shielding layer formed by coating TiO2 with lignin; the transition layer is composed of 32-64 PLA / PBAT alternating microlayers, and the multiple alternating transition layers form a zigzag gas barrier path; ag-coated ZIF-8 nanoparticles are loaded on the paper base layer, so that long-acting antibiosis is realized by slowly releasing silver ions; and the inner layer adopts a PPC / PBS blend to support the heat sealing layer with adjustable heat sealing strength. According to the preparation process, a gradient micro-layer structure is constructed through a multi-runner co-extrusion die head and a layer multiplier, silver ions are loaded to ZIF-8 through an ultrasonic-vacuum impregnation process, the hydroxyl density of the surface of the paper base layer is improved through plasma treatment, good interlayer strength is achieved, ester bond crosslinking is induced in a pre-irradiation mode, and the product is prepared. The paper-based composite film has ultraviolet shielding, gradient blocking, slow-release antibacterial and controllable heat sealing performance, the interface bonding strength of a traditional paper-based composite film is greatly improved, all components are biodegradable, and the paper-based composite film is suitable for packaging of food, medicine and the like.

The invention provides a multi-zone temperature control electrostatic chuck and a plasma processing device. The multi-zone temperature control electrostatic chuck comprises at least one of a grid temperature control module and a radial partition temperature control module. The grid temperature control module comprises a plurality of first independent temperature control units arranged in an array; the radial partition temperature control module comprises a plurality of annular second independent temperature control units; each of the first independent temperature control unit and the second independent temperature control unit comprises a partition variable heating structure; the partition variable heating structure comprises a partition control piece, a first partition deformation piece and at least two first partition heating pieces, the first partition deformation piece comprises a first center and at least two first connecting claws, and the partition control piece is electrically connected with the first partition deformation piece and the first partition heating pieces; the first partition heating piece is connected with the end, away from the first center, of the first connecting claw. The multi-zone temperature control electrostatic chuck is used for balancing a local overheat area or a local supercooling area caused by uneven plasma distribution.

A control method of a plasma processing apparatus including a first electrode that places a workpiece thereon includes supplying a bias power to the first electrode, and supplying a source power having a frequency higher than that of the bias power into a plasma processing space. The source power has a first state and a second state. The control method further includes a first control process of alternately applying the first state and the second state of the source power in synchronization with a signal synchronized with a cycle of a radio frequency of the bias power, or a phase within one cycle of a reference electrical state that represents any one of a voltage, current, and electromagnetic field measured in a power feeding system of the bias power.

A system includes a processing chamber configured to perform a plasma process with respect to one or more substrates. The system further includes an electrostatic chuck disposed within the processing chamber. The electrostatic chuck includes one or more electrodes. The system further includes an analog filter electrically coupled to at least one electrode of the one or more electrodes. The analog filter includes an air-core coil including a first coil and a second coil disposed within the first coil. The first coil and the second coil together form an inductor.

The invention provides a photoresist removing method and a semiconductor device manufacturing method, when photoresist on a substrate needs to be removed, corresponding oxygen-free gas is introduced into a plasma processing chamber and plasma excitation is carried out, so that corresponding rays are generated and act on the surface of the photoresist, the surface of the photoresist is re-melted, and the photoresist on the substrate is removed; according to the method, the photoresist is cleaned by the wet method, and then the hard shell on the surface of the photoresist is removed, so that the photoresist removal capability of subsequent wet cleaning can be effectively improved, the wet cleaning time is shortened, the photoresist is effectively removed, meanwhile, residues generated after the photoresist is removed by wet cleaning can be effectively avoided, the product yield is further improved, and the general applicability is high. Moreover, the surface of the photoresist is re-melted by mainly utilizing the action of rays generated after plasma excitation is carried out on the oxygen-free gas to remove the hard shell on the surface of the photoresist, so that the problem of secondary influence on the exposed substrate caused by the existing dry photoresist removing processes such as a plasma ashing process and the like can be effectively avoided.

The invention relates to the technical field of semiconductor devices, in particular to a light-emitting diode epitaxial structure and a preparation method thereof. The light-emitting diode epitaxial structure comprises a substrate, an h-BN / O2 layer, a low-temperature GaN buffer layer, an N-type semiconductor layer, a multi-quantum well layer and a P-type semiconductor layer which are arranged in sequence, the h-BN / O2 layer subjected to oxygen plasma treatment is inserted between the heterogeneous substrate and the GaN epitaxial layer, the low-temperature GaN buffer layer is grown on the h-BN / O2 layer by controlling the process conditions, and the h-BN / O2 layer and the low-temperature GaN buffer layer are matched, so that lattice mismatch dislocation, residual stress and thermal mismatch of an epitaxial material grown on the heterogeneous substrate can be effectively modulated, the scattering efficiency under high current is improved, and the light emitting efficiency is improved. The probability of radiation recombination of the heteroepitaxial material is improved, and the requirement for heteroepitaxy is lowered.

A plasma processing apparatus includes a chamber, a substrate support in the chamber, a plasma generator, a bias power supply, an edge ring, a lifter, a switch, and a controller. At least one of the bias power supply or a radio-frequency power supply in the plasma generator is electrically coupled to a base in the substrate support. The lifter includes a conductive ring, a rod, an actuator, and a connector. The lifter raises and lowers the edge ring supported on the conductive ring. The connector electrically couples the conductive ring and the base. The switch changes between a first state in which the edge ring and the base are electrically coupled to each other and a second state in which the edge ring and the base are electrically disconnected from each other. The controller controls the switch.