KR20170103051A - Method of atmospheric pressure plasma discharge - Google Patents

Method of atmospheric pressure plasma discharge Download PDF

Info

Publication number
KR20170103051A
KR20170103051A KR1020160024911A KR20160024911A KR20170103051A KR 20170103051 A KR20170103051 A KR 20170103051A KR 1020160024911 A KR1020160024911 A KR 1020160024911A KR 20160024911 A KR20160024911 A KR 20160024911A KR 20170103051 A KR20170103051 A KR 20170103051A
Authority
KR
South Korea
Prior art keywords
helium
plasma discharge
chamber
argon
injected
Prior art date
Application number
KR1020160024911A
Other languages
Korean (ko)
Inventor
이상현
백승재
Original Assignee
한경대학교 산학협력단
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 한경대학교 산학협력단 filed Critical 한경대학교 산학협력단
Priority to KR1020160024911A priority Critical patent/KR20170103051A/en
Publication of KR20170103051A publication Critical patent/KR20170103051A/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32009—Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources
    • H01J37/32082—Radio frequency generated discharge
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/32—Gas-filled discharge tubes
    • H01J37/32431—Constructional details of the reactor
    • H01J37/3244—Gas supply means
    • H01J37/32449—Gas control, e.g. control of the gas flow
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
    • H05H1/00—Generating plasma; Handling plasma
    • H05H1/24—Generating plasma
    • H05H1/46—Generating plasma using applied electromagnetic fields, e.g. high frequency or microwave energy

Abstract

An atmospheric plasma discharge method and apparatus are presented. In the atmospheric plasma discharge method proposed in the present invention, argon is injected into a chamber to maintain the internal pressure of the chamber at a predetermined level. When the internal pressure of the chamber is maintained at a predetermined level, Performing helium plasma discharge using injected helium; stopping helium implantation after performing helium plasma discharge; performing helium plasma discharge; stopping helium implantation; And filling the chamber with a mixed gas.

Description

[0001] The present invention relates to a method of atmospheric pressure plasma discharge,

The present invention relates to a method and apparatus for helium addition for VHF atmospheric plasma ignition.

The discharge of the VHF atmospheric plasma is such that electrons accelerated by an electric field collide with gas molecules (that is, atoms) and gas molecules are ionized.

The factors for the plasma discharge are as follows. First, it requires a sufficient number of electrons to ignite the plasma. And it needs energy of electrons higher than ionization energy. The higher the frequency, the lower the kinetic energy of the electron as the pressure increases, and the plasma ignition becomes more difficult.

The ionization energy of argon (Ar) is 15.76 eV. The ionization energy of helium (He) is 24.59 eV. Helium is ignited at less energy because of the longer lifetime of the metastable state (ie, the excited state) helium, despite the higher ionization energy.

In an atmospheric plasma process, helium with a low discharge voltage is generally used. Helium is expensive and it is economically advantageous to replace it with argon. However, in an atmospheric plasma discharge in an argon atmosphere, a high voltage is required and it is difficult to obtain a stable plasma.

SUMMARY OF THE INVENTION The object of the present invention is to provide a plasma display apparatus capable of discharging helium (He) first and then stopping helium inflow and injecting argon at a low voltage to discharge an Ar plasma discharge (that is, a glow discharge) And a method and apparatus for discharging argon.

According to an aspect of the present invention, there is provided an atmospheric plasma discharge method comprising the steps of: injecting argon into a chamber to maintain an internal pressure of a chamber at a predetermined level of pressure; maintaining the internal pressure of the chamber at a predetermined level, Implanting helium into the pre-implanted chamber, performing a helium plasma discharge using the implanted helium, stopping the helium implantation after performing helium plasma discharge, helium implantation after performing helium plasma discharge, And injecting a predetermined gas to fill the chamber with the mixed gas.

The step of injecting argon into the chamber to maintain the internal pressure of the chamber at a predetermined magnitude of pressure provides only electrons for igniting the plasma without performing the argon plasma discharge.

The plasma begins to ignite the VHF atmospheric plasma as the electrons accelerated by the electric field collide with the gas molecules and ionize the gas molecules.

And the mixed plasma discharge is performed using the mixed gas to reduce the discharge voltage.

In another aspect, the atmospheric pressure plasma discharge apparatus proposed in the present invention includes a chamber into which a gas is injected, and a control unit that controls injection of the gas.

The control unit injects argon into the chamber to maintain the internal pressure of the chamber at a predetermined level, and when the internal pressure of the chamber is maintained at a predetermined level of pressure, helium is injected into the chamber After the helium plasma discharge is performed using the injected helium, the helium injection is stopped.

When argon is injected into the chamber and the pressure inside the chamber is maintained at a predetermined level of pressure, only the electrons are ignited to ignite the plasma without performing the argon plasma discharge.

After the helium plasma discharge is performed, the control unit stops the helium implantation and injects a predetermined gas to fill the chamber with the mixed gas.

According to embodiments of the present invention, in order to perform an argon (Ar) plasma discharge (that is, a glow discharge), first, helium (He) is discharged, Argon can be discharged.

1 is a view for explaining a breakdown voltage for an atmospheric plasma discharge according to an embodiment of the present invention.
2 is a flowchart illustrating an atmospheric plasma discharge method according to an embodiment of the present invention.
3 is a diagram showing the configuration of an atmospheric plasma discharge apparatus according to an embodiment of the present invention.
4 is a graph illustrating the ratio of helium to argon injected into a chamber according to an embodiment of the present invention.
5 is a graph for explaining an increase in a plasma discharge region according to an embodiment of the present invention.
6 is a graph illustrating the amount of gas entering the chamber in accordance with one embodiment of the present invention.
7 is a graph illustrating helium usage according to a thickness of a thin film according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view for explaining a breakdown voltage for an atmospheric plasma discharge according to an embodiment of the present invention.

Figures 1a and 1b are d = 15㎛, neon at 10-100kPa gas (Ne), helium (He), argon (Ar), experimental breakdown voltage (Breakdown voltage) and the Paschen curve according to the nitrogen (N 2) Paschen curve. (Reference: BAARS-HIBBE, L., et al., Journal of Physics D: Applied Physics , 2005, 38.4: 510.) High frequency glow discharges at atmospheric pressure with micro-structured electrode arrays. . The standard deviation of FIG. 1A represents the margin of deviation between the three manufactured mean squared error (MSE) samples. 1B shows the voltage-current characteristics of a DC Low Pressure Electrical Discharge Tube (cited by ROTH, JR Industrial Plasma Engineering Volume 1 Principles, Bristol and Philadelphia, 1995).

Referring to FIG. 1, at normal pressure, argon (Ar) has a breakdown voltage that is greater than helium (He).

The voltage that holds the plasma discharge (i. E., The glow discharge) is less than the breakdown voltage. When a high voltage is applied for the plasma discharge, the arc is easily discharged and induces defects on the substrate.

From these three facts, in order to perform an argon (Ar) plasma discharge (that is, a glow discharge), firstly helium (He) is discharged and then helium inflow is stopped and argon is injected, We propose a method of discharging.

In an atmospheric plasma process, helium with a low discharge voltage is generally used. Helium is expensive and it is economically advantageous to replace it with argon. However, in an atmospheric plasma discharge in an argon atmosphere, a high voltage is required and it is difficult to obtain a stable plasma. The proposed atmospheric plasma discharge method can obtain stable plasma at normal pressure.

2 is a flowchart illustrating an atmospheric plasma discharge method according to an embodiment of the present invention.

In the conventional atmospheric plasma discharge method, argon is injected into a chamber to maintain a pressure inside the chamber at a predetermined level (step 210). When the internal pressure of the chamber is maintained at a predetermined level, A helium plasma discharge is performed 230, a helium plasma discharge is performed, a helium implantation is stopped, and a predetermined gas is injected into the chamber to inject a mixed gas into the chamber Filling 240, performing a helium plasma discharge, and then stopping 250 helium implantation.

In step 210, argon is injected into the chamber to maintain the chamber's internal pressure at a predetermined magnitude of pressure. Argon is injected into the chamber to maintain the pressure inside the chamber at a high pressure. At this time, the injected argon does not perform the argon plasma discharge but provides only electrons to ignite the plasma.

In step 220, argon injects helium into the pre-injected chamber if the chamber's internal pressure is maintained at a predetermined magnitude of pressure. For atmospheric argon plasma discharge, helium is implanted into a chamber of argon-pre-implanted argon atmosphere. Because helium has a lower discharge voltage than argon, the argon helium gas mixture has a lower plasma discharge voltage than argon.

In step 230, a helium plasma discharge is performed using implanted helium. In other words, helium is added to perform argon-helium mixed plasma discharge. The plasma begins to ignite the VHF atmospheric plasma as the electrons accelerated by the electric field collide with the gas molecules and ionize the gas molecules.

In step 240, helium implantation is stopped after helium plasma discharge is performed. After a predetermined amount of helium is implanted to perform plasma discharge, helium implantation is stopped.

In step 250, helium plasma discharge is performed, helium implantation is stopped, and a predetermined gas is injected to fill the chamber with the mixed gas. After a normal-pressure helium plasma discharge, a desired gas (for example, argon, nitrogen, oxygen, hydrogen, etc.) is injected and the helium injection is stopped. Even after stopping the helium implantation after the plasma discharge, the plasma is continuously maintained using the mixed gas to be introduced. Thus, the discharge voltage can be reduced by performing the mixed plasma discharge using the mixed gas.

Compared with the plasma process using only helium, the proposed atmospheric plasma discharge method can reduce the amount of helium used and reduce the process cost.

3 is a diagram showing the configuration of an atmospheric plasma discharge apparatus according to an embodiment of the present invention.

The proposed atmospheric plasma discharge apparatus includes a chamber 310 into which a gas is injected and control units 321 and 322 that control the injection of the gas. The controller may be represented by a mass flow controller (MFC) as shown in FIG. The control unit according to an embodiment of the present invention is represented by MFC1 321 that controls the flow of argon 331 and MFC2 322 that controls the flow of helium 332. [

The control unit, that is, the MFC1 321, injects argon 331 into the chamber 310 to control the internal pressure of the chamber to be maintained at a predetermined level. At this time, the injected argon does not perform the argon plasma discharge but provides only electrons to ignite the plasma.

If the internal pressure of the chamber 310 is maintained at a predetermined level of pressure, then the control, i. E., MFC2 322, injects helium 332 into the chamber where argon has been pre-injected. Because helium has a lower discharge voltage than argon, the argon helium gas mixture has a lower plasma discharge voltage than argon.

Helium plasma discharge is performed using injected helium. In other words, helium is added to perform argon-helium mixed plasma discharge. The plasma begins to ignite the VHF atmospheric plasma as the electrons accelerated by the electric field collide with the gas molecules and ionize the gas molecules.

After performing the helium plasma discharge, MFC2 322 stops the helium 332 implant. After a predetermined amount of helium is implanted to perform plasma discharge, helium implantation is stopped.

After helium plasma discharge is performed, MFC2 322 stops injecting helium 332 and MFC2 321 injects a predetermined gas to fill the chamber with the mixed gas. After a normal-pressure helium plasma discharge, a desired gas (for example, argon, nitrogen, oxygen, hydrogen, etc.) is injected and the helium injection is stopped. Even after stopping the helium implantation after the plasma discharge, the plasma is continuously maintained using the mixed gas to be introduced. Thus, the discharge voltage can be reduced by performing the mixed plasma discharge using the mixed gas.

Compared with the plasma process using only helium, the proposed atmospheric plasma discharge apparatus can reduce the amount of helium used and reduce the process cost.

4 is a graph illustrating the ratio of helium to argon injected into a chamber according to an embodiment of the present invention.

4 (a) shows an injection flow rate 410 of argon injected into the chamber after the start of plasma ignition, FIG. 4 (b) shows an injection flow rate 420 of helium, FIG. Plasma ignition is initiated (440), and helium plasma discharge is performed by injecting helium for a period of time. After helium plasma discharge is performed, helium is stopped and argon is injected only after a certain period of time. Over time, the proportion of argon increases.

After the atmospheric helium plasma discharge, a desired gas (for example, argon, nitrogen, oxygen, hydrogen, etc.) may be injected. Even after stopping the helium implantation after the plasma discharge, the plasma is continuously maintained using the mixed gas to be introduced. Thus, the discharge voltage can be reduced by performing the mixed plasma discharge using the mixed gas.

5 is a graph for explaining an increase in a plasma discharge region according to an embodiment of the present invention.

Referring to FIG. 5, a plasma discharge region of argon at 50 MHz, an argon-helium plasma discharge region at 50 MHz, a plasma discharge region of argon at 60 MHz, and an argon-helium plasma discharge region at 60 MHz were shown.

The larger the pd value in the atmospheric pressure region, the larger the breakdown voltage is required. At the same power condition, a plasma discharge at a higher pd value means that the breakdown voltage is reduced.

Table 1 shows the plasma discharge region of argon at 50 MHz, the argon-helium plasma discharge region at 50 MHz, the plasma discharge region of argon at 60 MHz, and the argon-helium plasma discharge region at 60 MHz.

<Table 1>

Figure pat00001

<Table 2>

Figure pat00002

6 is a graph illustrating the amount of gas entering the chamber in accordance with one embodiment of the present invention.

6 (a) is a graph showing the flow rate of argon 610, FIG. 6 (b) is a flow rate 620 of helium with time, and FIG. 6 to be.

 First, argon is injected into the chamber to maintain the pressure inside the chamber at a predetermined level. Argon is injected into the chamber to maintain the pressure inside the chamber at a high pressure. At this time, the injected argon does not perform the argon plasma discharge but provides only electrons to ignite the plasma.

If the inner pressure of the chamber is maintained at a predetermined magnitude of pressure, helium is injected into the chamber where argon has been pre-injected at time 641. According to embodiments of the present invention, the internal pressure of the chamber can be adjusted to ~ 700 Torr.

For atmospheric argon plasma discharge, helium is implanted into a chamber of argon-pre-implanted argon atmosphere. Because helium has a lower discharge voltage than argon, the argon helium gas mixture has a lower plasma discharge voltage than argon.

From time 641, helium plasma discharge is performed using the injected helium. In other words, helium is added to perform argon-helium mixed plasma discharge. The plasma begins to ignite the VHF atmospheric plasma as the electrons accelerated by the electric field collide with the gas molecules and ionize the gas molecules.

After the helium plasma discharge is performed, helium implantation is stopped at time 642. After a predetermined amount of helium is implanted to perform plasma discharge, helium implantation is stopped.

After the helium plasma discharge is performed, the helium implantation is stopped and a predetermined gas is injected at time 643 to fill the chamber with the mixed gas. After the normal-pressure helium plasma discharge, a desired gas (for example, argon, nitrogen, oxygen, hydrogen, etc.) is injected and helium injection is stopped. Even after stopping the helium implantation after the plasma discharge, the plasma is continuously maintained using the mixed gas to be introduced. Thus, at time 643 the deposition of the Si thin film begins. Thus, the discharge voltage can be reduced by performing the mixed plasma discharge using the mixed gas.

7 is a graph illustrating helium usage according to a thickness of a thin film according to an embodiment of the present invention.

The deposition rate of the Si thin film according to an embodiment of the present invention is 2000 nm / min.

The proposed atmospheric plasma discharge method and apparatus are for obtaining stable plasma at normal pressure.

The plasma discharge method in the present invention is summarized in two ways. First, helium is injected into an argon atmosphere chamber for atmospheric argon plasma discharge. Because helium has a lower discharge voltage than argon, the argon helium gas mixture has a lower plasma discharge voltage than argon. Even after stopping the helium implantation after the plasma discharge, the plasma is maintained. Second, a desired gas (for example, argon, nitrogen, oxygen, hydrogen, etc.) is injected after the atmospheric helium plasma discharge and the helium injection is stopped. This method can reduce the process cost by reducing the amount of helium used, compared with a plasma process using only helium.

According to the proposed atmospheric-pressure plasma discharge method and apparatus, it is confirmed that the amount of helium gas for obtaining a 1000 nm thin film is reduced ten times as compared with the conventional technology.

The apparatus described above may be implemented as a hardware component, a software component, and / or a combination of hardware components and software components. For example, the apparatus and components described in the embodiments may be implemented within a computer system, such as, for example, a processor, a controller, an arithmetic logic unit (ALU), a digital signal processor, a microcomputer, a field programmable array (FPA) A programmable logic unit (PLU), a microprocessor, or any other device capable of executing and responding to instructions. The processing device may execute an operating system (OS) and one or more software applications running on the operating system. The processing device may also access, store, manipulate, process, and generate data in response to execution of the software. For ease of understanding, the processing apparatus may be described as being used singly, but those skilled in the art will recognize that the processing apparatus may have a plurality of processing elements and / As shown in FIG. For example, the processing unit may comprise a plurality of processors or one processor and one controller. Other processing configurations are also possible, such as a parallel processor.

The software may include a computer program, code, instructions, or a combination of one or more of the foregoing, and may be configured to configure the processing device to operate as desired or to process it collectively or collectively Device can be commanded. The software and / or data may be in the form of any type of machine, component, physical device, virtual equipment, computer storage media, or device , Or may be permanently or temporarily embodied in a transmitted signal wave. The software may be distributed over a networked computer system and stored or executed in a distributed manner. The software and data may be stored on one or more computer readable recording media.

The method according to an embodiment may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions to be recorded on the medium may be those specially designed and configured for the embodiments or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. For example, it is to be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, Lt; / RTI &gt; or equivalents, even if it is replaced or replaced.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

Claims (8)

In the atmospheric pressure plasma discharge method,
Injecting argon into the chamber to maintain the internal pressure of the chamber at a predetermined magnitude of pressure;
Injecting helium into the chamber where argon has been pre-injected if the chamber's internal pressure is maintained at a predetermined magnitude of pressure;
Performing helium plasma discharge using injected helium; And
Stopping helium implantation after performing helium plasma discharge
Wherein the plasma discharge is performed at a predetermined temperature. The method according to claim 1,
The step of injecting argon into the chamber to maintain the chamber's internal pressure at a predetermined magnitude of pressure comprises:
Without performing the argon plasma discharge, only the electrons for igniting the plasma
Atmospheric pressure plasma discharge method. 3. The method of claim 2,
In the plasma, electrons accelerated by an electric field collide with gas molecules, and gas molecules are ionized to start ignition of the VHF atmospheric plasma
Atmospheric pressure plasma discharge method. The method according to claim 1,
After the helium plasma discharge is performed, the helium implantation is stopped and a predetermined gas is injected to fill the chamber with the mixed gas
Further comprising the steps of: 5. The method of claim 4,
The mixed plasma discharge is performed using the mixed gas to reduce the discharge voltage
Atmospheric pressure plasma discharge method. In the atmospheric pressure plasma discharge apparatus,
A chamber into which gas is injected; And
A control unit for controlling the injection of the gas
Lt; / RTI &gt;
Wherein,
Argon is injected into the chamber to maintain the internal pressure of the chamber at a predetermined level, and when the internal pressure of the chamber is maintained at a predetermined level of pressure, helium is injected into the chamber in which argon has previously been injected, To perform helium plasma discharge and then to stop the helium implantation
Atmospheric pressure plasma discharge device. The method according to claim 6,
When argon is injected into the chamber and the pressure inside the chamber is maintained at a predetermined level of pressure, argon plasma discharge is not performed and only electrons are supplied to ignite the plasma
Atmospheric pressure plasma discharge device. The method according to claim 6,
Wherein,
After the helium plasma discharge is performed, the helium implantation is stopped and a predetermined gas is injected to fill the chamber with the mixed gas
Atmospheric pressure plasma discharge device.
KR1020160024911A 2016-03-02 2016-03-02 Method of atmospheric pressure plasma discharge KR20170103051A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020160024911A KR20170103051A (en) 2016-03-02 2016-03-02 Method of atmospheric pressure plasma discharge

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020160024911A KR20170103051A (en) 2016-03-02 2016-03-02 Method of atmospheric pressure plasma discharge

Publications (1)

Publication Number Publication Date
KR20170103051A true KR20170103051A (en) 2017-09-13

Family

ID=59967570

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020160024911A KR20170103051A (en) 2016-03-02 2016-03-02 Method of atmospheric pressure plasma discharge

Country Status (1)

Country Link
KR (1) KR20170103051A (en)

Similar Documents

Publication Publication Date Title
Balcon et al. Numerical model of an argon atmospheric pressure RF discharge
US9418859B2 (en) Plasma-enhanced etching in an augmented plasma processing system
JP4822240B2 (en) Method and apparatus for low voltage plasma doping using double pulses.
US5133826A (en) Electron cyclotron resonance plasma source
Akishev et al. Negative corona, glow and spark discharges in ambient air and transitions between them
US7808184B2 (en) Methods and apparatus for generating strongly-ionized plasmas with ionizational instabilities
US9059398B2 (en) Methods for etching materials used in MRAM applications
Gammino et al. Review on high current 2.45 GHz electron cyclotron resonance sources
KR20010039749A (en) Method for providing pulsed plasma during a portion of a semiconductor wafer process
US20160358784A1 (en) Plasma-enhanced etching in an augmented plasma processing system
TWI620268B (en) Method and apparatus for esc charge control for wafer clamping
Samir et al. Study on effect of neutral gas pressure on plasma characteristics in capacitive RF argon glow discharges at low pressure by fluid modeling
De la Cal et al. First-wall cleaning and isotope control studies by ICRF conditioning in Tore Supra with a permanent magnetic field
KR100881990B1 (en) Inductively coupled plasma firing method
KR20170103051A (en) Method of atmospheric pressure plasma discharge
EP3139403A1 (en) Cyclical plasma etching
Kudryavtsev et al. Townsend discharge instability on the right-hand branch of the Paschen curve
Stockli et al. Recent performance of the SNS H− source for 1-MW neutron production
Generalov et al. Method for significantly increasing the stability limit of the discharge in fast-flow large-volume lasers
US20070243713A1 (en) Apparatus and method for generating activated hydrogen for plasma stripping
JP3405321B2 (en) Operation method of ion source and ion beam irradiation device
US20090283502A1 (en) Plasma processing apparatus and control method for plasma processing apparatus
US9105451B2 (en) Plasma processing method and plasma processing apparatus
Payman et al. Development of a 50-A heaterless hollow cathode for electric thrusters
US20200343004A1 (en) Low pressure plasma mode

Legal Events

Date Code Title Description
A201 Request for examination
E902 Notification of reason for refusal
AMND Amendment
E601 Decision to refuse application
AMND Amendment