Microwave plasma processing unit
|発明の名称 （英語）||Microwave plasma processing unit|
[Problem] To provide a microwave plasma treatment apparatus that is not provided with complicated, long gas flow paths inside a dielectric substrate, to stabilize generation and retention of a plasma, and can generate a highly uniform, high-density, stable low-temperature plasma not only at low atmospheric pressures but also at middle atmospheric pressures and high atmospheric pressures. [Solution] In a micro plasma treatment apparatus including a dielectric substrate, a microwave introducing section, a microstrip line, an earth conductor, a gas inlet, a plasma generating section, and a nozzle for blowing out a plasma, the gas inlet is provided at the earth conductor or the microstrip line, and the gas inlet is provided with a diameter preferably smaller than a cut-off wavelength determined depending on a cross-section of the gas inlet, to prevent leakage of a microwave.
(From EP3264866 A1)
In recent years, development of materials and production techniques have been shown to be a plasma processing technique in many applications it is essential to the present invention.The plasma has a high ratio (非) while maintaining the thermal balance, because it can produce a high density of radicals at low temperatures has been widely used in a dry processing technique.
The atmospheric pressure (1torr ∼ 100torr) and (1torr or less) from the intermediate pressure between the atmospheric pressure plasma in won (source) in the presence of one of the plasma jet is utilized.The plasma jet from the nozzle of the device since the extraction (blowout), on which the semiconductor wafer or the like, using plasma CVD (chemical vapor phase synthesis), etching, ashing (resist treatments), plasma nitridation, and air cleaning, sterilization, and the like are useful in the treatment of sterilization of the present invention.
Currently, in order to generate a plasma jet, DC arc discharge or dc pulse discharge using well known methods.However, the DC pulse discharge or DC arc electric discharge method is used, it is easier to deteriorate the electrode, the reactive gas cannot be used in a variety of problems such as that of the present invention has.
In addition, methods of using a dielectric barrier discharge are well known.However, in a method using a dielectric barrier discharge, discharge is generated on the filaments (狀) point, a high density of radical generation may not be to such a highly pure product having various problems.
In addition, the plasma jet generating apparatus using an electrodeless type are also known.For example, to a high frequency of VHF (30 field 300MHz) using an inductively coupled thermal plasma generating device is proposed (see Patent document 1) are present.However, the plasma jet generating apparatus has been proposed that impedance matching is complicated, the scale of the structure may not be the problem that, because of the high voltage electrical circuit is also used in the fabrication and operation of the apparatus can have a variety of limitations on the present invention there is a problem.
On the other hand, using a microwave plasma jet generated has the following advantages.
(1) Microwave power source is inexpensive.
(2) Electrodeless operation is possible, long life and to maintain the discharge.
(3) Impedance matching is possible in a simple device.
(4) Better coupling efficiency of the microwave plasma.
(5) To the exterior of the radiation loss is, where it is needed to power can be reduced to a concentrate.
(6) Wide pressure range including at atmospheric pressure in the high density plasma is generated stably.
However, the conventional plasma generating apparatus using a microwave power of the microwave transmission line in the pipe as a waveguide and is used, the structure of a microwave transmission circuit is large and expensive operation to which it has been difficult to power or the like of the present invention there is a problem.
In recent years, instead of the conventional waveguide, a microstrip transmission line small power microwave plasma jet apparatus was produced using this method has been proposed (see Patent document 2, 3 and non Patent Literature 1, 2).
Fig. 15 in which, using conventional microstrip line of one example of a plasma jet generating device in perspective.The apparatus, one end of a cross section of the dielectric substrate (1) (端 部) provided in the microwave input unit (13) (section), towards the other end of the dielectric substrate (1), the tapered portion (14) is formed of a dielectric substrate (1), a gas flow passage (23) provided inside the dielectric substrate (1) is provided on one side of the transfer of microwave power, a microstrip line (11) dielectric substrate (1) covering one surface to the other one of the ground conductor (12), and the corresponding grounding conductor (12) of the microstrip line is (11) provided between the plasma generation portion (25), and plasma discharge (ejection) of the present invention is composed of the nozzle (24).
In the plasma jet generating apparatus, the gas, which is provided on the side of the dielectric substrate (1) 2 (22, 22) of the gas input port (23, 23) from the gas flow path through the conduit is in the plasma generation portion (25), a width of 10mm from the nozzle (24) to the outside of the dielectric substrate (1) is taken out of the plenum.
Microwave (2. 45GHz) Power, microwave coaxial interconnect (31) in a dielectric substrate (1) are introduced through, between the earth conductor (12) of a microstrip line (11) and the whole (propagation; propagate) thereby, the concentration of the plasma generating portion (25).In this way, plasma is generated, together with the gas stream (flow) from the nozzle (24) to the outside of the dielectric substrate (1) are taken out.
On the other hand, the plasma processes in order to improve the productivity in, a plasma processing on a large area having a width of the possible development of a plasma jet has been demanded.The microstrip line above a plasma generator is used, its structure, a dielectric substrate, or the like to the ground conductor hostexchangeauthority microstrip line scale by array (see Patent document 2) it is possible, it is expected to be promising and others.
1. A dielectric substrate, said dielectric substrate and the surface of the rear end of a second surface 1 on one of the other end (端 部) provided from a microstrip line and over, the first face of the dielectric substrate 1 a second surface opposite to the other end on one of the 2 from an end portion of the conductor and provided over the ground, provided at one end of said dielectric substrate, wherein the microstrip line and the ground conductor between the microwave input unit for inputting the microwave, the microwave input from the input unit for generating a plasma by microwaves and a space, in addition, the microstrip line and the ground conductor is disposed between the plasma generator and the space, wherein the ground conductors or microstrip line installed, the plasma generating unit for supplying gas to the gas input port, wherein the plasma generator with the gas supplied to the plasma generated by microwaves, the other end of the dielectric substrate and provided with nozzles for ejecting from the microwave plasma processing apparatus characterized in that it.
2. Method according to claim 1, wherein the diameter of the gas input, wherein the barrier is defined by the cross section of the gas input is smaller than the wavelength, the microwave plasma processing apparatus.
3. Method according to claim 1 or 2, wherein the first or second surface of the dielectric substrate 2 to 1, wherein the conductive plate of the microstrip line or groove is fitted into the earth with the microwave plasma processing apparatus characterized in that it.
4. Method according to any one of claims 1-3, wherein the dielectric substrate, the other end of the dielectric substrate has a thickness gradually smaller toward the taper portion having a shape that is provided with a microwave plasma processing apparatus characterized in that the.
5. Method according to any one of claims 1-4, wherein the ground conductors or microstrip line at the input port 2 is provided in the gas, the gas input port of each other by supplying gas species, plasma discharge characteristic and the plasma treatment to alter the properties of the microwave plasma processing apparatus.
6. Method according to claim 5, wherein the ground conductors or microstrip line on the input port 2 is provided at least one gas, any gas in the vaporization of the liquid material supplied to the input port means and the microwave plasma processing apparatus characterized in that it.
7. Method according to any one of claims 1-6, microstrip line dielectric substrate is provided on a first surface in contact with the dielectric substrate 2, wherein the first dielectric substrate 2 from one end of the other end of the ground conductor 2 provided over the first, the second microstrip line and the ground conductor 2 is disposed between the first space and the plasma generation portion 2, wherein the supply gas to the plasma generation portion 2 to, wherein the first and second ground conductor 2 provided on the gas input port 2, wherein the gas input port 2 provided for supplying the gas to the first gas supply means 2, wherein the first gas supplied to the plasma generation portion 2 with the plasma generated by microwaves, wherein the first dielectric substrate 2 to be ejected from the other end portion of a third (ejection) of the nozzle 2 the microwave plasma processing apparatus.
8. Method according to any one of claims 1 to 7 wherein the microwave plasma apparatus according to claim, wherein the dielectric substrate and the ground conductor to the public, are aligned laterally, to a longitudinal axis and configured to generate a plasma of the plasma processing apparatus of the microwave.
9. 1 Method according to any one of the first 8 of the microwave plasma apparatus according to claim, a rare gas, or a reactive gas, or a mixed gas of rare gas and reactive gas is supplied, the atmospheric pressure plasma in the intermediate or anticyclone microwave plasma processing apparatus so as to generate.
|参考情報 （研究プロジェクト等）||Innovative Plasma Processing Group, AIST|
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