KR101320237B1 - Vacuum pump utilizing electron momentum transference - Google Patents

Abstract

The present invention is provided with an electron generating source in the sealed vacuum pump and provided with an electron focusing positive electrode for forming an electric field capable of accelerating electrons on the vacuum pump outlet side,
It is a vacuum pump that delivers the momentum by discharging the gas particles in the vacuum pump when the accelerated electrons move to the discharge capacity of the vacuum pump.
In addition, the ultrasonic vibration unit is provided on one side of the vacuum pump to apply ultrasonic vibration to prevent the gas particles in the vacuum pump from being physically adsorbed on the inner wall surface of the vacuum pump, thereby improving the vacuum and exhaust speed.
The present invention has a simple structure that does not require a mechanical configuration in the high vacuum region or ultra-high vacuum region and according to the nature of the residual gas particles to be discharged, even the particles which are difficult to ionize are smoothly discharged and the new gas in the vacuum vessel. It is a vacuum pump that uses the momentum transfer of electrons, which is characterized by being continuously operable with the outlet of the vacuum pump open even when particles are generated.

Description

Vacuum pump utilizing electron momentum transference

The present invention relates to a vacuum pump, and more particularly, to a vacuum pump using the momentum of electrons to deliver the momentum of the accelerated electrons to the gas particles in the vacuum pump and to apply the ultrasonic vibration to the vacuum pump to perform the exhaust action. .

The vacuum degree is divided into low vacuum, high vacuum (HV) and ultrahigh vacuum (UHV) according to the vacuum degree, and the vacuum degree is 1 atm ~ 10 ^-3 torr, 10 ^-3 to 10 ^-7 torr And 10 ⁻⁸ torr or less (760 torr = 1 atmosphere).

The low vacuum pump mainly uses a volumetric vacuum pump that repeatedly deflates and expands a space accommodating the fluid provided inside the vacuum pump and discharges air to the outside, and the high vacuum pump mainly uses a vacuum. A momentum transfer vacuum pump is used to transfer the momentum to the gas particles in the pump to increase the density of the gas particles on the outlet side and exhaust the gas particles. To obtain ultra-high vacuum, a capture pump that captures and removes residual gas particles in the chamber is mainly used. use.

A vacuum pump is used to remove the internal gas particles in the sealed container, that is, to increase the vacuum level. The vacuum pump can not operate as a single vacuum pump from the atmospheric pressure to the ultra-high vacuum region but operates at the vacuum degree of each region. By a combination of pumps.

To achieve high vacuum, oil rotary vacuum pump or mechanical pump, which is a low vacuum pump, is used as a backing pump, and a diffusion pump or turbo molecular pump is combined. In order to operate a high vacuum pump or an ultra high vacuum pump, such as a getter pump, an ion pump or a cold / hot pump connected to the mechanical pump and the turbo molecular pump to obtain an ultra-high vacuum degree, The low vacuum pump acts as a backing pump until a certain level of initial vacuum is reached.

Momentum transfer to obtain high vacuum The vacuum pumps are classified according to the method of delivering the momentum.The oil diffusion pump exhausts the vaporized oil vapor particles by impinging the momentum to the vacuum pump outlet side. In operation, the dry screw vacuum pump is coupled by a pair of blades of the rotating screw to impart momentum to the gas particles to exhaust the internal air, and the turbo molecular pump is a multi-layered metal fan fan that rotates at high speed and is a vacuum pump. It impinges on the gas particles inside and gives direction to the vacuum pump outlet side, and the molecular drag pump transfers the momentum to the rotation direction of the rotor, that is, the outlet side of the vacuum pump, which physically adsorbs the gas particles to the surface of the rotating rotor. The principle of most high vacuum pumps that are mainly used in industrial sites such as Direct flow is applied directly to the vacuum pump outlet. Mechanical vacuum pumps, such as turbomolecular pumps, require precise machining technology, and incur regular maintenance costs due to wear of parts during use. In the case of a wet vacuum pump using oil such as a pump, there is a problem of contaminating the inside of the vacuum chamber by the backflow of oil vapor.

Ultra high vacuum pumps include cold and hot pumps, ion pumps, and getter pumps, and cryogenic vacuum pumps maintain temperatures at very low temperatures to achieve ultra-vacuum conditions, reducing the mobility of gas particles and reducing The particles are trapped to increase the degree of vacuum.The ion pump installs electrodes such as anode and cathode in the vacuum chamber, forms an electric field, ionizes gas particles, and captures and removes them on metal surfaces such as titanium.The gettering pump is barium or titanium. Physically, the metal having good collection ability is deposited in the vacuum chamber to collect gas particles into the deposition film to increase the degree of vacuum.

The existing ultra-high vacuum pumps, such as cold / hot pumps, ion pumps, and diffusion pumps by titanium diffusion, trap the gas particles in the vacuum pump while the exit of the vacuum pump is sealed. If a new gas is generated in a reactor in a state, the capture pump is restricted in use, and the ion pump is difficult to remove particles such as inert gas, which is difficult to ionize, and the collected gas particles are collected in the vacuum pump even after the gas particles are collected. Such as re-emission from.

The gas particle behavior at atmospheric pressure is dense and dense, so the collision rate between the gas particles is higher than the collision rate between the gas particles and the inner wall of the vacuum pump. As the ratio of gas particles to the inner wall of the vacuum pump is similar, the inner wall of the vacuum pump starts to affect the flow of gas particles during the exhaust operation, and the gas particle density inside the vacuum pump in the high vacuum region or the ultra high vacuum region. Since the collision rate between the gas particles and the inner wall of the vacuum pump is much higher than the collision between the gas particles, the amount of gas particles remaining on the inner wall of the vacuum pump is reduced and physically reattached in order to obtain an ultra-high vacuum state. The residence time of the gas particles to be adsorbed should be minimized.

When the gas particles reach the inner wall of the vacuum pump, they are temporarily stopped by the physical adsorption phenomenon and released again or trapped on the inner wall and remain. This is because at the molecular level, the surface state of the inner wall of the vacuum pump is very irregular and rough. As it rises, the inner wall of the vacuum pump has a very important influence on the exhaust speed, so in order to obtain an ultra-high vacuum state, a baking process for heating the vacuum pump body itself by several hundred degrees or an inert gas such as argon is introduced into the vacuum pump. There is a problem that a cumbersome pretreatment process is required to make the vacuum state of the ultra-high vacuum region, such as to remove foreign substances remaining on the inner wall of the vacuum pump by injection.

Existing vacuum pumps used in semiconductor processes or electronic display processes are exposed to various toxic and corrosive gas particles, which is a fatal factor to shorten the life of mechanical parts and internal parts of vacuum pumps that are usually made of metal by corrosive gas particles. Teflon, nickel, cemented carbide, etc. may be coated inside the vacuum pump to extend the life of the vacuum pump. However, there is a limit, so it is usually necessary to repair overhaul every few months. There are also problems that include risk factors such as productivity degradation and workplace environmental pollution.

The present invention is a problem of the conventional vacuum pump described above-namely, regular maintenance cost due to wear and corrosion of parts and risks due to toxic gas liquid, backflow of evaporated oil, the sealing of the outlet when using the capture pump to obtain ultra-high vacuum degree Continuous process is impossible and baking process is required to remove gas particles remaining on the inner wall of the vacuum pump and gas particles are removed from the inner wall of the vacuum pump using inert gas, and ion pumps are difficult to remove. It was conceived to solve the problem, and it has a simple structure that does not require mechanical configuration in the high vacuum region or the ultra high vacuum region, and smoothly discharges even the particles which are difficult to ionize according to the nature of the residual gas particles to be discharged. The outlet of the vacuum pump even if new gas particles are generated in the vacuum vessel. A vacuum that can be operated continuously in one state and has a means for easily removing foreign matter molecules remaining on the inner wall of the vacuum pump, eliminating the cumbersome baking process and removing residual gas inside the vacuum pump for inert gas. Providing a pump is a challenge to be solved.

An electron emission source and a negative electrode are provided on one inner side of the vacuum pump, an electron focusing positive electrode is provided on the other side of the vacuum pump discharge direction, and an electron focusing electrode power source for forming an electric field is applied between the negative electrode and the electron focusing electrode. Accelerated electrons 31 generated and accelerated by the electron emission source 30 are accelerated toward the vacuum pump outlet 12 to transfer the momentum by the collision of the accelerated electrons to the gas particles 32 inside the vacuum pump, and are evacuated. One side of the 10 may further include an ultrasonic vibration unit 80, a high frequency power supply device 85, an electron acceleration positive electrode 40 and an electron acceleration electrode power supply 70, the electron emission source is CRT, VFD, It is a solution of the problem to use a hot electron or cold electron generator, which is an electron-emitting structure of any one of FED and SED.

Since the vacuum pump of the present invention uses the accelerated electrons as the direct mediator of the momentum transfer by colliding with the gas particles, the structure is simple because there is no mechanical element, and it can effectively transfer the momentum to the gas particles inside the vacuum pump to be discharged. When used together with a backing pump, it is possible to easily discharge particles that are difficult to ionize to realize a high vacuum state with high cleanness, and when the vacuum pump body is manufactured using Pyrex or quartz glass, Excellent corrosion resistance can significantly reduce the management cost, and equipped with ultrasonic vibration means on one side of the vacuum pump body can easily remove the foreign matter molecules remaining on the inner wall of the vacuum pump without a separate pretreatment process.

Unlike conventional capture pumps such as getter pumps and ion pumps that operate in the ultra-high vacuum region, the vacuum pump that provides the momentum transfer and the ultrasonic vibration to the vacuum pump body does not need to seal the outlet of the vacuum pump during operation. It can easily cope with the reactive continuous process in which gas particles are generated in the vacuum chamber, and it is easy to manufacture and easy to maintain due to its simple structure.

1 is a block diagram of a vacuum pump using the momentum transfer of electrons.
2 is a conceptual diagram for explaining the momentum transfer operation of the former.
3 is a conceptual diagram showing the configuration of various types of electron emission sources.
4 is a conceptual diagram showing the state of the inner wall of the vacuum pump of the nanoscale.
Figure 5 is a block diagram of an embodiment having a momentum transfer of the electrons and ultrasonic vibration means.

In order to remove the gas particles inside the sealed container, that is, to use the vacuum pump as a means to increase the degree of vacuum, and to obtain a high degree of vacuum, the degree of vacuum that can be operated on the inlet and outlet sides of the vacuum pump according to the performance characteristics of each vacuum pump. Therefore, a multi-stage vacuum pump system consisting of a series or parallel combination of two or three vacuum pumps in an operating vacuum degree region of each vacuum pump between the atmospheric pressure and the ultra-high vacuum state region obtains a high or ultra high vacuum state.

In order to obtain a high vacuum state, a low vacuum pump, a mechanical pump or an oil rotary vacuum pump, is used as a backing pump, and a diffusion pump or a turbo molecular pump is used. Is composed of a vacuum pump system by connecting to the outlet side of the crankcase, and to obtain ultra-high vacuum degree, a getter pump, an ion pump, or a cryogenic pump, which is a capture pump, is obtained in the vacuum pump system. It is used to deposit and equip the pump in the connection or the vacuum container.

The present invention is an electron emission source (30) inside the vacuum pump (10) by removing the existing high vacuum pump structure of the conventional vacuum pump to transfer the momentum to the gas particles in the vacuum pump using a liquid such as precision mechanical elements or vacuum oil Electrons are generated, the electron concentrating positive electrode 50 and the electron emission source 30 provided on the vacuum pump outlet 12 side are formed as the negative electrode 20, and an electric field is formed between the two electrodes. Accelerated electrons 31 generated and accelerated at 30 are accelerated toward the vacuum pump outlet 12 along the electric line of force.

1 is a configuration diagram of a vacuum pump using the momentum transfer of the present invention, the electron emission source 30 is a tungsten filament as a heat source in a low work function (alkali earth metal oxide) easy to release electrons even at low temperatures When one material such as barium oxide is coated on the surface of the tungsten filament and then heated by applying the electron emission source power supply unit 60 to the tungsten filament, it is easy to emit heat electrons even at low temperatures, and the electron is discharged to the vacuum pump outlet 12 in the opposite direction. After the focusing positive electrode 50 is formed and an electric field is formed using the tungsten filament as the electron emission source 30 as the negative electrode 20, the accelerated electrons 31 generated and accelerated by the electron emission source 30 along the electric field lines of the formed electric field. ) Reaches the electron focusing positive electrode 50, which collides with the gas particles 32 inside the vacuum pump 10 in the path to reach the product of the mass of the acceleration electrons 31 and the velocity at the time of collision. The momentum is transmitted, the density of the gas particles 32 is increased on the vacuum pump outlet 12 side of the vacuum pump 10 provided with the electron focusing positive electrode 50, thereby connecting the duct 90 and the auxiliary vacuum pump 100. The exhaust is made by.

The ultrasonic vibrator 80 provided at one side of the vacuum pump 10 receives power from the high frequency power supply 85 and applies ultrasonic vibration to the vacuum pump 10 to physically adsorb the surface of the vacuum pump inner wall 82. The residence time of the gas particles to be minimized.

The momentum transfer model for the acceleration electrons 31 hitting the gas particles 32 is the momentum due to the collision between the electron beam etch (E-beam lithography) or the accelerated electron beam and the phosphor of the CRT (Cathod-ray tube), which is a traditional electronic display. And energy transfer models.

In Equation 1 and FIG. 2, the momentum before and after the collision between the acceleration electrons 31 and the gas particles 32 in the vacuum pump 10 is preserved so that the gas particles are the velocity vector U ₂ of the final gas particles after the collision. Where the force exerted by the gas particles from the electron is the product of the rate of change of the velocity vector (U ₂ ) and the mass of the gas particles, according to Newton's second law.

Since the direction of the gas particles after the collision is the direction of movement and acceleration of electrons generated from the electron emission source 30, the electron focusing positive electrode 50 side of the vacuum pump outlet, the direction of the gas particles after the collision is the direction of movement of the gas particles before the collision. The direction is in accordance with the law of parallelogram in the direction of motion in the direction of the exit of the vacuum pump delivered by the acceleration electrons 31 after the collision with. After the collision between the acceleration electrons 31 and the gas particles 32 for the first time, the direction of movement of the gas particles may not be the exit side, but in the process of colliding with the acceleration electrons 31 many times, the direction of movement of the gas particles gradually changes to the exit side. In the case where the gas particles are ionized by the collision with the acceleration electrons 31, when they are negatively ionized, they move by the electromagnetic force along the electric force line to the outlet side where the electron focusing electrodes 50 are located, similarly to the acceleration electrons 31. The electrons are neutralized at the surface of the surface) and discharged through the vacuum pump outlet 12, and when positively ionized, they move to the negative electrode 20 side. When the cation reaches the negative electrode, the cation neutralizes the electrons at the negative electrode and then moves to the vacuum pump outlet side by electron collision.

When the state inside the vacuum pump reaches a high vacuum region, the density of gas particles in the vacuum pump becomes thinner and the mean free path, which is the distance that the gas particles can move before colliding with other gas particles, is increased. In order for the particles to be discharged out through the backing pump, the density of the gas particles is increased at the outlet side of the vacuum pump or the inlet side of the subvacuum pump, so that the particle size of the subvacuum vacuum pump 100 is increased through the connection duct 90. The amount of gas particles entering the inside is increased.

The momentum of the acceleration electrons 31 is transmitted by the collision of the acceleration electrons 31 to the gas particles 32 moving in any disordered direction, so that the density of the gas particles 32 increases on the vacuum pump outlet 12 side. As a result, the amount of gas particles 32 introduced into and discharged into the auxiliary vacuum pump 100 through the connection duct 90 increases, so that the inside of the vacuum pump 10 becomes a high or ultra high vacuum state.

The electron emission mechanism of the electron emission source 30 provided in one side of the vacuum pump 10 of the present invention can be implemented by various methods such as hot electron emission, cold electron emission, and electron emission using a tunneling effect of electrons. For example, barium oxide having a low work function in tungsten filament, a electron gun of a cathode ray tube (CRT) or a vacuum fluorescent display (VFD), which uses hot electrons that emit electrons by heating. It is also possible to use a structure that is easy to emit electrons by applying the FED, that is, a cold electron emission structure of a field emission display (field emission display) for emitting electrons in a strong electric field may be used. FED is a structure that generates cold electrons by electric field in many electron guns that are realized in nanoscale on a substrate by electron beam etching and chemical etching.

3A is a conceptual diagram illustrating a hot electron emission mechanism of a cathode ray tube (CRT).

The basic structure is a vacuum tube consisting of three parts, the negative electrode 20, the electron acceleration positive electrode 40 and the electron focusing positive electrode 50, the heater is heated by receiving the power of the electron emission source power supply unit 60 in a closed vacuum state When the negative electrode 20 of the electron emission source 30 is heated, hot electrons are emitted from the surface of the negative electrode 20, and the emitted hot electrons move along the electric force line formed by the electron acceleration positive electrode 40 and the electron focusing positive electrode. Between the 20 and the electron acceleration positive electrode 40 is provided with an electrode acceleration electrode power source 70 for the electric field formation, between the negative electrode 20 and the electron focusing positive electrode 50 has an electron acceleration electrode power source 70 to the negative electrode 20 And a closed circuit that continuously flows by accelerating and focusing the hot electrons emitted from the electrons. The electron acceleration positive electrode 40 is generated from the negative electrode 20 to control the hot electrons flowing to the electron focusing positive electrode 50 such as acceleration or deceleration. station And the.

FIG. 3B is a conceptual diagram showing an electron emitting mechanism of a vacuum fluorescent display (VFD).

The basic structure is a structure of a three-pole vacuum tube similar to the CRT, and consists of three parts of a negative electrode, an electron acceleration positive electrode 40 and an electron focusing positive electrode 50 in a sealed vacuum tube. The negative electrode 20 has a plurality of filament shapes and emits electrons. It serves as a circle 30. That is, the electron emission source 30 is the negative electrode 20.

Filament, which is an electron emission source of VFD, is called a line cathode because it serves as a negative electrode 20. Since VFD uses low-speed electrons unlike the CRT, barium oxide has a low work function to facilitate electron emission on the surface of tungsten wire. The electron acceleration positive electrode 40 serves as a control electrode for accelerating or blocking the flow of electrons delivered to the electron focusing positive electrode 50 by processing a metal piece such as stainless into a mesh structure. .

The low speed electrons are classified by the potential difference between the electron focusing electrode power source 71 formed between the negative electrode and the electron focusing positive electrode 50 when the electrons generated from the electron emission sources of the CRT and the VFD are accelerated. The applied potential difference is about 20,000 volts, but VFD is only a few tens to hundreds of volts, so the difference in the speed of the accelerated electrons is significantly different.

3C is a conceptual diagram illustrating an electron emission mechanism of a field emission display (FED).

FED is a nanoscale implementation on a substrate in nanoscale on a substrate. Cold electrons are emitted through a conical emission tip 35 by an electric field without applying thermal energy in a sealed vacuum tube. Accelerated electrons 31 are accelerated and controlled by the 40 and the electron focusing positive electrode 50.

The material of the emission tip 35 is made of molybdenum (Mo), tungsten (W), nickel (Ni) metal or zinc oxide (ZnO), CNT (carbon nano tube), the method of forming the emission tip 35 is molybdenum , Tungsten metal or ZnO and CNT as a paste, followed by precision screen printing to form an emission tip tip, or direct growth of molybdenum metal or CNT on a substrate by chemical vapor deposition (CVD) or physical vapor deposition (PVD) processes To form. The emission tip 35 is formed on the negative electrode 20, the electron acceleration positive electrode 40 is formed on the insulating layer 51, and the electron focusing positive electrode 50 is provided on the upper portion of the insulation layer 51.

In addition to the electron generating source using the FED's emission tip 35, palladium oxide (PdO) is processed into ultra fine powder to form a planar electron source formed in a conical rather than conical form, and utilizes the tunneling effect of electrons between the narrow conductors of nanoscale on the substrate. The electron emitting structure of the surface-conduction electron-emitter display (SED) used as an electron emission source can also be used.

In the high vacuum or ultra high vacuum region, the density of gas particles in the vacuum pump is low, so the higher the vacuum degree of the vacuum pump, the higher the rate of collision between the gas particles and the inner wall of the vacuum pump, rather than the collision between the gas particles, the high vacuum region, especially ultra high vacuum In order to ensure a smooth venting operation in the area, the gas particles remaining on the inner wall of the vacuum pump and their residual time should be minimized.

When the gas particles reach the inner wall of the vacuum pump after disordered collision between the gas particles, the gas particles may be temporarily stopped by the physical adsorption phenomenon and then discharged again or may be trapped in the inner wall and remain. FIG. 4 shows the inner surface of the vacuum pump inner wall 82 at nanoscale. The surface of the vacuum pump inner wall surface 82 has a very important influence on the exhaust velocity in the state of high vacuum or ultra-high vacuum region. Therefore, in order to obtain the ultra-high vacuum state, the vacuum pump ( 10) The cumbersome pretreatment process is performed to make the vacuum state of high vacuum or ultra high vacuum region, such as heating the body itself or injecting gas such as argon into the vacuum pump to remove foreign matter molecules remaining on the inner wall surface 82 of the vacuum pump. need.

The present invention can easily remove foreign matter molecules on the inner wall of the vacuum pump without the need for such cumbersome pretreatment, prevent new foreign matter molecules from adsorbing during the exhaust operation, and minimize the residual time of physically adsorbed gas particles. The ultrasonic vibration unit 80 is provided on the body of the vacuum pump 10 and the ultrasonic vibration unit 80 applies high frequency power to the high frequency power supply 85 to apply ultrasonic vibration to the body of the vacuum pump 10.

5 is a block diagram showing a vacuum pump according to an embodiment of the present invention.

The vacuum pump 10 according to the embodiment is connected to the vacuum chamber outlet 201 of the vacuum chamber 200 through the vacuum pump inlet 11, the electron emission source for emitting hot electrons on one inside of the vacuum pump 10 30 is provided, and an electron acceleration positive electrode 40 for forming an electric field and a conical electron focusing electrode 50 for accelerating the emitted hot electrons are provided around the vacuum pump outlet 12.

The electron emission source 30 is a negative electrode 20 composed of one or a plurality of line filaments coated with barium oxide for reducing the work function around the tungsten wire for hot electron emission, and is accelerated by being discharged from the negative electrode 20. The electrons 31 are first accelerated by the electron accelerating positive electrode 40 and secondly accelerated by the conical electron concentrating positive electrode 50 to impinge on the gas particles in the vacuum pump to impart momentum to the gas particles 32 in the direction of the vacuum pump outlet. ) To increase the density. As the density of the vacuum pump outlet increases, the probability of introducing into the connection duct 90 also increases, and the gas particles 32 introduced into the connection duct 90 are connected to the auxiliary vacuum pump outlet 110 by the auxiliary vacuum pump 105. Exhaust through.

At this time, the voltage of the electron focusing electrode power source 71 applied between the negative electrode 20 and the electron focusing positive electrode 50 is limited to within a few thousand volts, so that the ionization rate due to the collision of the acceleration electrons of the gas particles is not too high. That is, the low-speed electrons are used to transfer momentum to the gas particles in the vacuum pump.

When the voltage of the electron focusing electrode power source is increased to tens of thousands of volts or more, the ionization rate of the gas particles rapidly increases due to the collision of the accelerating electrons, and the accelerated electrons and anions reaching the electron focusing electrode 50 generate X-rays, The material constituting the 50 is evaporated to shorten the life.

Electron acceleration positive electrode 40 is processed in a mesh form to uniform the electric field formed between the negative electrode 20 has the effect of uniformizing the flow of the acceleration electrons, but in the configuration of the present invention using the principle of electron momentum transfer It is not essential and can be removed.

The electron focusing positive electrode 50 attracts the accelerating electrons 31 passing through the mesh-shaped electron acceleration positive electrode 40, but processes them into a conical shape to increase the density of gas particles on the vacuum pump outlet 12 side. The tip of the conical electron focusing electrode is opened so that the gas particles having a higher density are introduced into the vacuum pump outlet 12.

The electron emission source shown in this embodiment has a structure for emitting hot electrons and includes an electron emission source power supply unit 60 as a power source for heating a tungsten wire coated with barium oxide, which is a negative electrode. AC is possible, but in the case of direct current, the temperature gradient between the two ends of the tungsten wire is severe due to the voltage drop caused by the tungsten wire. Therefore, the center tab of the transformer of the electron emission power supply unit 60 using a transformer having an AC power source and a center tap is provided. ) Is grounded to minimize the temperature gradient due to voltage drop.

The potential difference applied between the negative electrode 20 and the electron acceleration positive electrode 40 is the electron acceleration electrode power source 70 which is a direct current, and the negative electrode and the electron focusing electrode power source 71 is the electron focusing electrode power source 71 which is a direct current. To form an electric field, the potential difference of the electron focusing electrode power source is set higher than the electron acceleration electrode power source, and the potential difference of the electron focusing electrode power source is set to several thousand volts or less, so that the gas particles inside the vacuum pump by the acceleration electrons 31 of too high speed. (32) It prevents X-ray generation and surface damage of electron focusing electrode by ionization and the impact of electrons and anions of too high energy state on electron focusing electrode.

An ultrasonic vibration unit 80 is provided on one side of the vacuum pump 10 and a high frequency power source is applied using the high frequency power source device 85 as a power source of the ultrasonic vibration unit.

Ultrasound is a frequency of frequencies higher than about 20 kHz, which is a human audible frequency, and is widely used industrially as an ultrasonic cleaner. Ultrasonic vibrators made of piezoelectric ceramics whose volume changes when an electric power is applied when a high frequency power capable of varying the frequency is applied. It is applied to generate high frequency vibration.

The reason for applying the ultrasonic vibration to the vacuum pump is that the gas particle density inside the vacuum pump is rare under high vacuum or ultra high vacuum, so that the ratio of collision with the gas particles in the vacuum pump inner wall surface 82 is higher than that between the gas particles and the vacuum pump inner wall surface. The state of 82 is very rough at the nanoscale, so that the gas particles 32 are adsorbed to obstruct the exhaust of the gas particles 32, so that ultrasonic vibration is applied to the vacuum pump 10 to improve the degree of vacuum and the exhaust speed.

As the existing ultra-high vacuum pump, such as a cold / hot pump or an ion pump and a diffusion pump by titanium diffusion, traps the gas particles in the chamber while the outlet is blocked, new gases in the chamber during etching or the like in semiconductor or other nano processes, etc. There is a problem in that the use is limited, but in the case of a vacuum pump using the momentum transfer of the present invention, there is no need to block the vacuum pump outlet 12 of the vacuum pump, the continuous process of generating gas particles in the vacuum chamber 200 You can easily respond to. In addition, it is easy to manufacture as well as to maintain a simple structure can be easily applied to the industry.

Reference Signs List 10: vacuum pump 11: vacuum pump inlet 12: vacuum pump outlet 20: negative electrode 22: insulating layer 23: substrate 30: electron emission source 31: accelerator electron 32: gas particles 33: anion 34: cation 35: emission tip 40: electron Accelerated positive electrode 50: Electron focusing positive electrode 51: Insulation layer 60: Electron emission source power supply 70: Electron acceleration electrode power 71: Electron focus electrode power 80: Ultrasonic vibrator 82: Vacuum pump inner wall surface 85: High frequency power supply 90: Connection duct 100 : Auxiliary vacuum pump 110: auxiliary vacuum pump outlet 200: vacuum chamber 201: vacuum chamber outlet

Claims (4)

delete A vacuum pump having an electron emission source and a negative electrode inside one of the vacuum pumps, an electron focusing positive electrode on the other side of the vacuum pump discharge direction, and an electron focusing electrode power source for forming an electric field for electron acceleration between the negative electrode and the electron focusing electrode To

A vacuum pump, characterized in that it further comprises an ultrasonic vibration unit and a high frequency power supply on one side of the vacuum pump.
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