Vacuum pump and vacuum exhaust system

Abstract

Provided are a vacuum pump and a vacuum exhaust system with which it is possible to effectively clean reaction products accumulated in the vacuum pump with a small number of radical generators while improving the cleaning efficiency by the radical generators, and with which it is possible to reduce the operating cost. The present invention is provided with: a radical supply port (134A) provided in the vicinity of an exhaust-side outlet of an exhaust mechanism (133) so as to penetrate into a housing (110); and a radical supply mechanism (135) that supplies radicals (136) into the housing (110A) from the radical supply port (134A) and causes the supplied radicals (136) to flow to a site where reaction products in the exhaust mechanism (132) accumulate.

Description

Technical Field

[0001] The present invention relates to a vacuum pump and a vacuum exhaust system, and in particular to a vacuum pump and a vacuum exhaust system that can be used in a pressure range from low vacuum to ultra-high vacuum. Background Art

[0002] When manufacturing memory, integrated circuits, and semiconductor devices, in order to avoid the effects of dust in the air, it is necessary to dope and etch high-purity semiconductor substrates (wafers) in a high-vacuum chamber, and to exhaust the chamber using a vacuum pump such as a turbomolecular pump.

[0003] As such a vacuum pump, there is known a vacuum pump including a cylindrical housing, a cylindrical stator which is fixed by a nest in the housing and provided with a threaded groove, and a rotor which is supported in the stator so as to be rotatable at high speed.

[0004] In a vacuum pump, the gas sucked from the air inlet of the housing may undergo a phase change from gas to solid during the compression process inside the pump (inside the housing), and solidify inside the pump. As a result, a solidified product (hereinafter referred to as a "reaction product") may accumulate inside the pump and block the gas flow path, which is an undesirable situation.

[0005] As a method for solving this problem, a technique of supplying radicals into the interior of a vacuum pump to clean the reaction product has been proposed (for example, refer to Patent Document 1).

[0006] Free radicals are substances that forcefully peel off, activate and remove the solidified materials accumulated inside the pump by applying high voltage to raw gas such as nitrogen trifluoride (NF3). However, there is a problem that free radicals lose their activity if they come into contact with the surface of the introduction tube introduced into the pump or the components of the pump. Therefore, in the case where a free radical generating device is provided near the air intake port of the vacuum pump as described in Patent Document 1, although the cleaning effect near the air intake port is high, it is often impossible to clean the reaction products accumulated near the exhaust port.

[0007] On the other hand, the reaction products often accumulate near the exhaust port of the vacuum pump, and it is necessary to effectively clean the area near the exhaust port. Therefore, a vacuum pump has been proposed that has a free radical generator installed not only near the air intake port but also near the middle of the exhaust mechanism of the vacuum pump, and adopts a technique that allows the free radicals to reach the part to be cleaned before the free radicals lose their activity (for example, refer to Patent Document 2).

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Publication No. 2008-248825

[0011] Patent Document 2: Japanese Patent Application Publication No. 2022-17864 Summary of the invention

[0012] Problems to be solved by the invention

[0013] However, although the vacuum pump described in Patent Document 2 can effectively clean both the vicinity of the air intake port and the vicinity of the air exhaust port, it is necessary to install radical generators at multiple locations, which has a problem of increasing the cost.

[0014] In addition, since the supplied radicals flow unidirectionally from the air inlet side to the air outlet side in the vacuum pump described in Patent Document 2, when the radical supply port is disposed near the center of the portion where the reaction product accumulates, the downstream side of the radical supply port can be cleaned, but the upstream side of the radical supply port cannot be cleaned. Therefore, in order to clean the upstream side of the radical supply port, a radical supply port for cleaning the upstream side is required separately.

[0015] Therefore, in order to provide a vacuum pump and a vacuum exhaust system that can improve the cleaning efficiency based on the free radical generating device and effectively clean the reaction products accumulated in the vacuum pump with fewer free radical generating devices, while reducing the operating cost, a technical problem that needs to be solved arises, and the purpose of the present invention is to solve this problem.

[0016] Means used to solve problems

[0017] The present invention is proposed to achieve the above-mentioned purpose. The invention recorded in Technical Solution 1 provides a vacuum pump, which is a vacuum pump comprising a shell having an air intake port and an air exhaust port, and an exhaust mechanism arranged on the inner side of the aforementioned shell, and comprising: a free radical supply port, which is arranged near the exhaust side outlet of the aforementioned exhaust mechanism and is set to pass through the aforementioned shell; and a free radical supply mechanism, which supplies free radicals into the aforementioned shell from the aforementioned free radical supply port, so that the aforementioned supplied free radicals flow to the location where the reaction products are accumulated in the aforementioned exhaust mechanism.

[0018] According to this structure, by supplying free radicals into the housing from a free radical supply port disposed between the air intake port and the exhaust port, and switching the path for making the free radicals flow toward the downstream side of the free radical supply port and the free radical path toward the upstream side of the free radical supply port, the supplied free radicals are spread over the entire part of the housing that needs to be cleaned. Moreover, the reaction products of the exhaust mechanism and the like accumulated in the housing can be activated and effectively removed. Thus, even a small number of free radical generating devices can effectively remove the reaction products, so it is possible to take into account both the reduction in the cost of cleaning parts and the reduction in the operating cost in the cleaning system inside the vacuum pump.

[0019] The invention described in claim 2 provides a vacuum pump, wherein in the structure described in claim 1, an intermediate port for discharging the radicals to the outside of the housing is provided between the air intake port and the radical supply port.

[0020] According to this structure, the free radicals supplied from the free radical supply port can be discharged to the outside of the housing not only through the exhaust port but also through the intermediate port. That is, by providing the intermediate port at a position where the reaction products of the exhaust mechanism accumulated in the housing can be activated and effectively removed, and by discharging the free radicals to the outside of the housing through the intermediate port as needed, the cleaning effect can be maximized. In addition, since the removed reaction products do not flow on the upstream side, the upstream side can be prevented from being contaminated.

[0021] The invention described in Technical Solution 3 provides a vacuum pump, which, in the structure described in Technical Solution 2, comprises: a suction / exhaust mechanism capable of sucking the free radicals supplied into the aforementioned shell through the aforementioned exhaust port or the aforementioned intermediate port and exhausting them to the outside of the aforementioned shell; and an exhaust switching valve capable of switching the exhaust path of the aforementioned free radicals to either the aforementioned exhaust port or the aforementioned intermediate port.

[0022] According to this structure, by switching the discharge path by the exhaust switching valve, the free radicals supplied from the free radical supply port into the housing can be discharged to the outside of the housing from one of the exhaust ports or the intermediate ports. Therefore, by selecting the position of the exhaust port or the intermediate port that can activate and effectively remove the reaction products of the exhaust mechanism accumulated in the housing, and by switching the discharge path of the free radicals by the exhaust switching valve, the cleaning effect can be maximized.

[0023] The invention described in Technical Solution 4 provides a vacuum pump, in which, in the structure described in Technical Solution 1, at least a portion of the aforementioned exhaust mechanism is a turbomolecular pump mechanism, and the turbomolecular pump mechanism has a rotating body having a plurality of rotating blades arranged in multiple layers in the axial direction, and a plurality of fixed blades arranged between the aforementioned plurality of rotating blades.

[0024] According to this structure, in a turbomolecular pump mechanism in which at least a portion of the exhaust mechanism has a rotating body having a plurality of rotating blades arranged in multiple layers in the axial direction, and a plurality of fixed blades arranged between the plurality of rotating blades, the reaction products of the exhaust mechanism accumulated in the casing can be activated and effectively removed.

[0025] The invention described in Technical Solution 5 provides a vacuum pump. In the structure described in Technical Solution 1, at least a portion of the aforementioned exhaust mechanism is a Sigband type pump mechanism, and the Sigband type pump mechanism has a rotating circular plate, a fixed circular plate, and a vortex groove arranged at at least a portion of the opposing surfaces of the aforementioned rotating circular plate and the aforementioned fixed circular plate.

[0026] According to this structure, in a Sigband type pump mechanism in which at least a portion of the exhaust mechanism has a rotating circular plate, a fixed circular plate, and a spiral groove provided at at least a portion of the opposing surfaces of the rotating circular plate and the fixed circular plate, the reaction products of the exhaust mechanism accumulated in the casing can be activated and effectively removed.

[0027] The invention described in Technical Solution 6 provides a vacuum pump. In the structure described in Technical Solution 1, at least a portion of the aforementioned exhaust mechanism is a Holweg-type pump mechanism, and the Holweg-type pump mechanism comprises a rotating cylinder, a fixed cylinder, and a threaded groove arranged at at least a portion of the opposing surfaces of the aforementioned rotating cylinder and the aforementioned fixed cylinder.

[0028] According to this structure, in a Holweg type pump mechanism in which at least a portion of the exhaust mechanism includes a rotating cylinder, a fixed cylinder, and a threaded groove provided at at least a portion of the opposing surfaces of the rotating cylinder and the fixed cylinder, the reaction products of the exhaust mechanism accumulated in the casing can be activated and effectively removed.

[0029] The invention described in Technical Solution 7 provides a vacuum pump. In the structure described in Technical Solution 2, the exhaust mechanism is composed of at least two of a turbomolecular pump mechanism, a Sigban pump mechanism or a Holweg pump mechanism. The turbomolecular pump mechanism has a rotating body having a plurality of rotating blades arranged in multiple layers in the axial direction, and a plurality of fixed blades arranged between the plurality of rotating blades. The Sigban pump mechanism has a rotating disc, a fixed disc, and a vortex groove arranged at at least a portion of the opposing surfaces of the rotating disc and the fixed disc. The Holweg pump mechanism has a rotating cylinder, a fixed cylinder, and a threaded groove arranged at at least a portion of the opposing surfaces of the rotating cylinder and the fixed cylinder. The intermediate port is arranged near the boundary of the adjacent turbomolecular pump mechanism, the Sigban pump mechanism or the Holweg pump mechanism.

[0030] According to this structure, in a vacuum pump in which at least a portion of the exhaust mechanism is composed of at least two or more of a Siegbain type pump mechanism having a rotating circular plate, a fixed circular plate, and a spiral groove provided at at least a portion of the opposing surfaces of the rotating circular plate and the fixed circular plate, or a Holweg type pump mechanism having a rotating cylinder, a fixed cylinder, and a threaded groove provided at at least a portion of the opposing surfaces of the rotating cylinder and the fixed cylinder, the reaction products of the exhaust mechanism accumulated in the casing can be activated and effectively removed.

[0031] The invention described in Technical Solution 8 provides a vacuum exhaust system, comprising: a vacuum pump, comprising a shell having an air intake port and an exhaust port, an exhaust mechanism arranged on the inner side of the shell, and a free radical supply port arranged near the exhaust side outlet of the exhaust mechanism and penetrating into the shell; and a free radical supply mechanism, which supplies free radicals into the shell from the free radical supply port and supplies the supplied free radicals to the location where the reaction products accumulate in the exhaust mechanism.

[0032] According to this structure, by supplying free radicals into the housing from a free radical supply port disposed between the air intake port and the exhaust port, and switching the path for making the free radicals flow toward the downstream side of the free radical supply port and the free radical path toward the upstream side of the free radical supply port, the supplied free radicals are spread over the entire part of the housing that needs to be cleaned. Moreover, the reaction products of the exhaust mechanism and the like accumulated in the housing can be activated and effectively removed. Thus, even a small number of free radical generating devices can effectively remove the reaction products, so a vacuum exhaust system that can take into account both the reduction in the cost of cleaning parts and the reduction in the operating cost in the cleaning system inside the vacuum pump can be realized.

[0033] Effects of the Invention

[0034] According to the present invention, if free radicals are supplied into the housing from a free radical supply port disposed between the air intake port and the air exhaust port, the supplied free radicals are distributed throughout the entire portion of the housing that needs to be cleaned, and the reaction products accumulated in the exhaust mechanism and the like in the housing can be activated and effectively removed. Thus, the reaction products can be effectively removed with a relatively small number of free radical generating devices, so that the cost of cleaning parts and the operating cost of the cleaning system inside the vacuum pump can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a longitudinal sectional view of a turbomolecular pump shown as a first example of a vacuum pump according to an embodiment of the present invention, and is a diagram for explaining a discharge path when the state is switched to discharge radicals from an intermediate port.

[0036] Figure 2It is a longitudinal sectional view of a turbomolecular pump shown as a first example of a vacuum pump according to an embodiment of the present invention, and is a diagram for explaining a discharge path when a state is switched to discharge radicals from a discharge port.

[0037] Figure 3 This is a diagram showing an example of an amplifier circuit in the turbomolecular pump of the first embodiment.

[0038] Figure 4 This is a timing chart showing a control example in which a current command value detected by the amplifier circuit in the turbomolecular pump according to the first embodiment is larger than the detected value.

[0039] Figure 5 This is a timing chart showing a control example in which a current command value detected by the amplifier circuit in the turbomolecular pump according to the first embodiment is smaller than the detected value.

[0040] Figure 6 It is a longitudinal sectional view of a turbomolecular pump shown as a second example of the vacuum pump according to the embodiment of the present invention.

[0041] Figure 7 It is a longitudinal sectional view of a turbomolecular pump shown as a third example of the vacuum pump according to the embodiment of the present invention.

[0042] Figure 8 It is a longitudinal sectional view of a turbomolecular pump shown as a fourth example of the vacuum pump according to the embodiment of the present invention.

[0043] Fig. 9 It is a longitudinal sectional view of a turbomolecular pump shown as a fifth example of the vacuum pump according to the embodiment of the present invention. DETAILED DESCRIPTION

[0044] In order to achieve the purpose of providing a vacuum pump and a vacuum exhaust system that can improve the cleaning efficiency based on a free radical generating device and effectively clean the reaction products accumulated in a vacuum pump with fewer free radical generating devices, while reducing the operating cost, the present invention is achieved by making the following structure: a vacuum pump is a vacuum pump comprising a shell with an air intake port and an exhaust port, and an exhaust mechanism arranged on the inner side of the aforementioned shell, comprising: a free radical supply port, which is arranged near the exhaust side outlet of the aforementioned exhaust mechanism and is set to pass through the aforementioned shell; and a free radical supply mechanism, which supplies free radicals into the aforementioned shell from the aforementioned free radical supply port, so that the aforementioned supplied free radicals flow to the location where the reaction products are accumulated in the aforementioned exhaust mechanism.

[0045] Example

[0046] Hereinafter, an embodiment of the present invention will be described in detail based on the accompanying drawings. In addition, in the following embodiments, when referring to the number, value, amount, range, etc. of constituent elements, except for the cases that are specifically indicated and the cases that are obviously limited to a specific number in principle, they are not limited to the specific number and may be more than or less than the specific number.

[0047] Furthermore, when referring to the shapes and positional relationships of components, etc., except for cases specifically stated or cases that are obviously considered not to be such in principle, etc., those that are substantially similar or similar to the shapes, etc. are included.

[0048] In addition, the drawings may be exaggerated by enlarging characteristic parts to make the features easier to understand, and the size ratios of the components are not limited to the same as the actual ones. In addition, in the cross-sectional views, in order to make the cross-sectional structure of the components easier to understand, the section lines of some components may be omitted.

[0049] In addition, in the following description, expressions indicating directions such as up and down, left and right are not absolute expressions, and although they are suitable for the case where the various parts of the vacuum pump of the present invention are in the depicted postures, when the postures are changed, they should be interpreted in accordance with the changes in the postures. In addition, the same reference numerals are given to the same elements throughout the entire description of the embodiments.

[0050] exist Figure 1 and Figure 2 : shows a longitudinal cross-sectional view of the turbo molecular pump 100A. Figure 1 and Figure 2 In the turbomolecular pump 100A, an air inlet 101 is formed at the upper end of the cylindrical outer cylinder 127, which is the housing. In addition, a rotating body 103 is provided inside the outer cylinder 127, and a plurality of rotating blades 102 (102a, 102b, 102c, ...) as turbine blades for sucking and discharging gas are formed radially and multi-layered on the periphery of the rotating body 103. A rotor shaft 113 is installed at the center of the rotating body 103, and the rotor shaft 113 is suspended and supported in the air by, for example, a five-axis controlled magnetic bearing and is position-controlled.

[0051] The upper radial electromagnet 104 has four electromagnets arranged in pairs on the X-axis and the Y-axis. Four upper radial sensors 107 are provided near the upper radial electromagnet 104 and corresponding to each of the upper radial electromagnets 104. The upper radial sensor 107 uses, for example, an inductance sensor having a conductive winding, an eddy current sensor, etc., and detects the position of the rotor shaft 113 based on the change in the inductance of the conductive winding that changes corresponding to the position of the rotor shaft 113. The upper radial sensor 107 is configured to detect the radial displacement of the rotor shaft 113, that is, the rotating body 103 fixed thereto, and transmit it to the control device 200.

[0052] In the control device 200, for example, a compensation circuit having a PID adjustment function generates an excitation control command signal for the upper radial electromagnet 104 based on a position signal detected by the upper radial sensor 107. Figure 3 The amplifier circuit 150 (described later) controls the excitation of the upper radial electromagnet 104 based on the excitation control command signal, thereby adjusting the upper radial position of the rotor shaft 113 .

[0053] The rotor shaft 113 is formed of a high magnetic permeability material (iron, stainless steel, etc.) and is attracted by the magnetic force of the upper radial electromagnet 104. Such adjustment is performed independently in the X-axis direction and the Y-axis direction. In addition, the lower radial electromagnet 105 and the lower radial sensor 108 are arranged in the same manner as the upper radial electromagnet 104 and the upper radial sensor 107, and the radial position of the lower side of the rotor shaft 113 is adjusted in the same manner as the radial position of the upper side.

[0054] Furthermore, the axial electromagnets 106A and 106B are arranged to sandwich a disc-shaped metal disk 111 provided at the lower part of the rotor shaft 113. The metal disk 111 is made of a high magnetic permeability material such as iron. An axial sensor 109 is provided to detect the axial displacement of the rotor shaft 113, and is configured to send its axial position signal to the control device 200.

[0055] Moreover, in the control device 200, for example, a compensation circuit with a PID adjustment function generates respective excitation control command signals for the axial electromagnet 106A and the axial electromagnet 106B based on the axial position signal detected by the axial sensor 109, and the amplifier circuit 150 performs excitation control on the axial electromagnet 106A and the axial electromagnet 106B respectively based on these excitation control command signals. As a result, the axial electromagnet 106A attracts the metal disk 111 upward by means of magnetic force, and the axial electromagnet 106B attracts the metal disk 111 downward, and the axial position of the rotor shaft 113 is adjusted.

[0056] In this way, the control device 200 appropriately adjusts the magnetic force exerted by the axial electromagnets 106A and 106B on the metal disk 111, so that the rotor shaft 113 is magnetically suspended in the axial direction and is held in space without contact. In addition, the amplifier circuit 150 for controlling the excitation of the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B will be described later.

[0057] On the other hand, the motor 121 includes a plurality of magnetic poles arranged circumferentially so as to surround the rotor shaft 113. Each magnetic pole is controlled by the control device 200 so as to rotate and drive the rotor shaft 113 via electromagnetic force acting between the magnetic poles and the rotor shaft 113. In addition, a rotation speed sensor such as a Hall element, a resolver, or an encoder (not shown) is incorporated in the motor 121, and the rotation speed of the rotor shaft 113 is detected based on the detection signal of the rotation speed sensor.

[0058] Furthermore, for example, a phase sensor (not shown) is mounted near the lower radial sensor 108 to detect the rotation phase of the rotor shaft 113. The control device 200 detects the position of the magnetic pole using the detection signal of the phase sensor and the rotation speed sensor.

[0059] A plurality of fixed blades 123 (123a, 123b, 123c, ...) are provided with a slight gap from the rotating blades 102 (102a, 102b, 102c, ...). The rotating blades 102 (102a, 102b, 102c, ...) are formed to be inclined at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113 in order to move exhaust gas molecules downward by collision.

[0060] In addition, the stationary blades 123 are also formed to be inclined at a predetermined angle from a plane perpendicular to the axis of the rotor shaft 113, and are arranged inwardly of the outer cylinder 127, alternately with the layers of the rotating blades 102. The outer peripheral ends of the stationary blades 123 are supported in a state of being inserted between a plurality of stacked stationary blade spacers 125 (125a, 125b, 125c, ...).

[0061] The fixed blade spacer 125 is an annular member, for example, made of a metal such as aluminum, iron, stainless steel, copper, or an alloy containing these metals as components. An outer cylinder 127 is fixed to the outer periphery of the fixed blade spacer 125 with a slight gap. A base portion 129 is provided at the bottom of the outer cylinder 127. An exhaust port 133 is formed in the base portion 129 and communicates with the outside. Exhaust gas that enters the air intake port 101 from the chamber side and is transferred to the base portion 129 is transported to the exhaust port 133.

[0062] Furthermore, according to the purpose of the turbomolecular pump 100A, a threaded spacer 131 is provided between the lower part of the fixed blade spacer 125 and the base part 129. The threaded spacer 131 is a cylindrical member made of a metal such as aluminum, copper, stainless steel, iron, or an alloy containing these metals as components, and a plurality of spiral thread grooves 131a are engraved on its inner circumference. The spiral direction of the thread groove 131a is the direction in which the molecules of the exhaust gas are transferred to the exhaust port 133 side when the molecules move in the rotation direction of the rotating body 103. A cylindrical part 102m is suspended from the lowermost part of the rotating body 103 that is connected to the rotating blades 102 (102a, 102b, 102c, ...). The outer circumference of the cylindrical part 102m is cylindrical, and extends toward the inner circumference of the threaded spacer 131, and is close to the inner circumference of the threaded spacer 131 with a predetermined gap therebetween. The exhaust gas transferred to the thread groove 131 a by the rotary blade 102 and the fixed blade 123 is sent to the base portion 129 while being guided by the thread groove 131 a.

[0063] The base 129 is a disc-shaped component constituting the base of the turbomolecular pump 100A, and is generally made of metal such as iron, aluminum, stainless steel, etc. The base 129 physically holds the turbomolecular pump 100A and also serves as a heat conduction path, so it is preferable to use a metal such as iron, aluminum, copper, etc. that has rigidity and high thermal conductivity.

[0064] In such a structure, when the rotary blade 102 is driven to rotate together with the rotor shaft 113 by the motor 121, the exhaust gas is sucked from the chamber through the air inlet 101 by the action of the rotary blade 102 and the fixed blade 123. The exhaust gas sucked from the air inlet 101 passes between the rotary blade 102 and the fixed blade 123 and is transferred to the base portion 129. At this time, the temperature of the rotary blade 102 rises due to the friction heat generated when the exhaust gas contacts the rotary blade 102, the conduction of heat generated by the motor 121, etc., but the heat is transferred to the fixed blade 123 side by radiation or conduction by gas molecules of the exhaust gas.

[0065] The stationary blade spacers 125 are joined to each other at the outer circumference, and transfer heat received by the stationary blades 123 from the rotary blades 102 , friction heat generated when the exhaust gas contacts the stationary blades 123 , and the like to the main body casing 114 .

[0066] In the above description, it is assumed that the threaded spacer 131 is disposed on the outer periphery of the cylindrical portion 102m of the rotating body 103, and the thread groove 131a is engraved on the inner peripheral surface of the threaded spacer 131. However, there is also a case where the thread groove is engraved on the outer peripheral surface of the cylindrical portion 102m and a spacer having a cylindrical inner peripheral surface is disposed around it.

[0067] In addition, depending on the purpose of the turbomolecular pump 100A, there is also the following situation: the electrical equipment part is covered with a stator column 122, and the inside of the stator column 122 is maintained at a specified pressure with a purge gas so that the gas sucked from the air intake port 101 does not invade the electrical equipment part. The electrical equipment part is composed of an upper radial electromagnet 104, an upper radial sensor 107, a motor 121, a lower radial electromagnet 105, a lower radial sensor 108, axial electromagnets 106A, 106B, an axial sensor 109, etc.

[0068] In this case, a pipe (not shown) is provided in the base portion 129, and the purge gas is introduced through the pipe. The introduced purge gas passes through the gaps between the protection bearing 120 and the rotor shaft 113, between the rotor and the stator of the motor 121, and between the stator column 122 and the inner circumferential cylindrical portion of the rotary blade 102, and is sent to the exhaust port 133.

[0069] Here, the turbomolecular pump 100A requires the determination of the model and the control based on the inherent parameters (e.g., the characteristics corresponding to the model) that have been adjusted respectively. In order to save the control parameters, the turbomolecular pump 100A is equipped with an electronic circuit unit 141 in its main body. The electronic circuit unit 141 is composed of a semiconductor memory such as an EEP-ROM, electronic parts such as semiconductor elements for accessing it, and a substrate 143 for mounting them. The electronic circuit unit 141 is accommodated in the lower part of the base 129 constituting the lower part of the turbomolecular pump 100A, such as the lower part of the rotation speed sensor not shown in the figure near the center, and is closed by an airtight bottom cover 145.

[0070] In addition, in the semiconductor manufacturing process, among the process gases introduced into the chamber, there is a process gas having a property of becoming solid if its pressure becomes higher than a specified value or its temperature becomes lower than a specified value. Inside the turbomolecular pump 100, the pressure of the exhaust gas is the lowest at the air intake port 101 and the highest at the exhaust port 133. During the process gas being transferred from the air intake port 101 to the exhaust port 133, if its pressure becomes higher than a specified value or its temperature becomes lower than a specified value, the process gas becomes solid and adheres to and accumulates inside the turbomolecular pump 100A.

[0071] For example, when SiCl4 is used as a process gas in an Al etching device, it can be seen from the vapor pressure curve that at low vacuum (760 [torr] ~ 10-2 [torr]) and low temperature (about 20 [°C]), solid products (such as AlCl3) precipitate and adhere to the inside of the turbomolecular pump 100A. Therefore, if the precipitate of the process gas is deposited inside the turbomolecular pump 100A, the deposit narrows the pump flow path, which becomes a cause of the performance degradation of the turbomolecular pump 100A. In addition, the aforementioned product is in a state where it is easy to solidify and adhere to the portion with higher pressure near the exhaust port and the threaded spacer 131.

[0072] Therefore, in order to solve this problem, in the past, a heater not shown in the figure and an annular water-cooling pipe 149 were wound around the outer periphery of the base portion 129, and a temperature sensor not shown in the figure (such as a thermistor) was embedded in the base portion 129, and based on the signal of the temperature sensor, the heating of the heater and the cooling by the water-cooling pipe 149 were controlled (hereinafter referred to as TMS. TMS; Temperature Management System) to maintain the temperature of the base portion 129 at a certain higher temperature (set temperature).

[0073] Next, regarding the turbo molecular pump 100A configured as above, the amplifier circuit 150 for controlling the excitation of the upper radial electromagnet 104, the lower radial electromagnet 105, and the axial electromagnets 106A and 106B will be described. Figure 3 A circuit diagram of the amplifier circuit 150 is shown in FIG.

[0074] exist Figure 3 In the embodiment, one end of the electromagnet winding 151 constituting the upper radial electromagnet 104 and the like is connected to the positive electrode 171a of the power source 171 via the transistor 161, and the other end is connected to the negative electrode 171b of the power source 171 via the current detection circuit 181 and the transistor 162. The transistors 161 and 162 are so-called power MOSFETs, and have a structure in which a diode is connected between the source and the drain.

[0075] At this time, the cathode terminal 161a of the diode of transistor 161 is connected to the positive electrode 171a, and the anode terminal 161b is connected to one end of the electromagnet winding 151. In addition, the cathode terminal 162a of the diode of transistor 162 is connected to the current detection circuit 181, and the anode terminal 162b is connected to the negative electrode 171b.

[0076] On the other hand, the cathode terminal 165a of the diode 165 for current regeneration is connected to one end of the electromagnet winding 151, and the anode terminal 165b is connected to the negative electrode 171b. In addition, similarly, the cathode terminal 166a of the diode 166 for current regeneration is connected to the positive electrode 171a, and the anode terminal 166b is connected to the other end of the electromagnet winding 151 via the current detection circuit 181. And, the current detection circuit 181 is composed of, for example, a Hall sensor type current sensor and a resistor element.

[0077] Therefore, when the magnetic bearing is controlled in five axes and there are ten electromagnets 104 , 105 , 106A, and 106B in total, the same amplifier circuit 150 is configured for each electromagnet, and ten amplifier circuits 150 are connected in parallel to the power supply 171 .

[0078] Furthermore, the amplification control circuit 191 is constituted by, for example, a digital signal processor unit (hereinafter referred to as a DSP unit) not shown in the control device 200 , and switches the transistors 161 and 162 between on and off.

[0079] The amplifier control circuit 191 compares the current value detected by the current detection circuit 181 (a signal reflecting the current value is referred to as a current detection signal 191c) with a predetermined current command value. Then, based on the comparison result, the size of the pulse width (pulse width time Tp1, Tp2) generated within one cycle of PWM control, that is, the control cycle Ts is determined. As a result, the gate drive signals 191a, 191b having the pulse width are output from the amplifier control circuit 191 to the gate terminals of the transistors 161, 162.

[0080] In addition, when the rotation speed of the rotating body 103 passes through the resonance point during the acceleration operation, when interference occurs during the constant speed operation, etc., it is necessary to control the position of the rotating body 103 at high speed and with strong force. Therefore, a high voltage of about 50V, for example, is used as the power supply 171 so that a sharp increase (or decrease) in the current flowing in the electromagnet winding 151 can be achieved. In addition, a capacitor (not shown) is usually connected between the positive electrode 171a and the negative electrode 171b of the power supply 171 for the purpose of stabilizing the power supply 171.

[0081] In such a configuration, when both transistors 161 and 162 are turned on, the current flowing through the electromagnet winding 151 (hereinafter referred to as electromagnet current iL) increases, and when both transistors 161 and 162 are turned off, the electromagnet current iL decreases.

[0082] In addition, if one of the transistors 161 and 162 is turned on and the other is turned off, a so-called flywheel current is maintained. Moreover, by making the flywheel current flow through the amplifier circuit 150 in this way, the hysteresis loss in the amplifier circuit 150 can be reduced, and the power consumption of the circuit as a whole can be suppressed to a low level. In addition, by controlling the transistors 161 and 162 in this way, high-frequency noise such as harmonics generated in the turbomolecular pump 100A can be reduced. Furthermore, by measuring the flywheel current with the current detection circuit 181, the electromagnet current iL flowing in the electromagnet winding 151 can be detected.

[0083] That is, when the detected current value is smaller than the current command value, Figure 4 As shown, both transistors 161 and 162 are turned on only once in the control cycle Ts (e.g., 100 μs) for a time period corresponding to the pulse width time Tp1. Therefore, the electromagnet current iL during this period increases toward the current value iLmax (not shown) that can flow from the positive electrode 171a to the negative electrode 171b via the transistors 161 and 162.

[0084] On the other hand, when the detected current value is larger than the current command value, Figure 5 As shown, both transistors 161 and 162 are turned off only once in the control cycle Ts for a time corresponding to the pulse width time Tp2. Therefore, the electromagnet current iL during this period decreases toward the current value iLmin (not shown) that can be regenerated from the negative electrode 171b to the positive electrode 171a via the diodes 165 and 166.

[0085] In either case, one of the transistors 161 and 162 is turned on after the pulse width time Tp1 or Tp2 has passed. Therefore, during this period, a current continues to flow through the amplifier circuit 150 .

[0086] In the turbomolecular pump 100A, the gas sucked from the air inlet 101 of the housing 110A having the outer tube 127 and the base 129 and formed in a substantially cylindrical shape may undergo a phase change from gas to solid during compression inside the housing 110A and solidify inside the housing 110A. As a result, a solidified product (hereinafter referred to as a "reaction product") may accumulate inside the housing 110A and block the gas flow path, which may be an undesirable condition.

[0087] In addition, the turbomolecular pump 100A of the first embodiment has an exhaust mechanism 132, which constitutes a turbomolecular pump mechanism 301 on the upstream side of the housing 110A and constitutes a thread groove pump mechanism 302 on the downstream side. In addition, the turbomolecular pump mechanism 301 is provided with a rotating body 103 having a plurality of rotating blades 102 arranged in multiple layers in the axial direction, and a plurality of fixed blades 123 arranged between the plurality of rotating blades 102. On the other hand, the thread groove pump mechanism 302 is provided with a cylindrical portion 102m as a rotating cylinder that rotates integrally with the rotating body 103, a threaded spacer 131 as a fixed cylinder, and a thread groove 131a on the inner peripheral surface of the threaded spacer 131, which is an opposing surface facing the outer peripheral surface of the rotating cylindrical portion 102m, constituting a so-called Holweg type pump mechanism. In addition, an intermediate port 112 penetrating into the housing 110A is provided at a substantially middle portion between the upstream and downstream sides of the housing 110A, that is, near the boundary between the turbomolecular pump mechanism 301 and the threaded groove pump mechanism 302 configured as a Holweg type pump mechanism, and a radical supply port 134A penetrating into the housing 110A is provided near the exhaust side outlet of the exhaust mechanism 132, that is, near the exhaust port 133. Furthermore, a radical supply mechanism 135 is connected to the radical supply port 134A, and a radical 136 is supplied from the radical supply mechanism 135 to the housing 110A via the radical supply port 134A, so that the supplied radical 136 flows to the portion where the reaction product of the exhaust mechanism 132 is accumulated, and the reaction product accumulated on the exhaust mechanism 132 is activated and removed by the radical 136. The supply of the radical 136 from the radical supply mechanism 135 is controlled by the control device 200, and an appropriate amount is supplied. Furthermore, an on-off valve 140A is provided between the radical supply mechanism 135 and the radical supply port 134A to control on / off the supply of radicals 136 from the radical supply mechanism 135 . The opening and closing of the on-off valve 140A is controlled by the control device 200 .

[0088] In addition, a purge gas supply port 139 for supplying a purge gas 138 from a purge gas supply mechanism 137 into the housing 110A is provided between the intake port 101 and the exhaust port 133 in the housing 110A. The purge gas supply port 139 is provided on the upstream side (the turbomolecular pump mechanism 301 side) of the intermediate port 112 and on the downstream side of the intake port 101. The supply of the purge gas 138 from the purge gas supply mechanism 137 is controlled by the control device 200 and supplied in an appropriate amount.

[0089] In addition, the free radical 136 is a fluorine free radical that can remove the solidified material accumulated inside the housing 110A, such as nitrogen trifluoride (NF3) and the like, which is generated by applying a high voltage to a raw material gas. On the other hand, the purge gas 138 is an inactive gas that pushes the free radical 136 toward the downstream side so that the free radical 136 supplied from the free radical supply port 134A to the housing 110A flows to a predetermined position in the housing 110A toward the air inlet 101 side and does not flow further toward the air inlet 101 side, such as nitrogen (N2).

[0090] In addition, the intermediate port 112 and the exhaust port 133 are connected to the suction / exhaust mechanism 201 via the exhaust switching valve 202A or the exhaust switching valve 202B, respectively. The suction / exhaust mechanism 201 has a suction pump that forcibly sucks / exhausts the free radicals 136 and the purge gas 138 in the housing 110A to the outside of the housing 110A via the intermediate port 112 and the exhaust port 133. The exhaust switching valve 202A interposed between the intermediate port 112 and the suction / exhaust mechanism 201 and the exhaust switching valve 202B interposed between the exhaust port 133 and the suction / exhaust mechanism 201 are opening and closing valves that are controlled by the control device 200. Here, the exhaust switching valve 202A and the exhaust switching valve 202B are selectively opened and closed by the control device 200 when using free radicals 136 and purge gas 138 to remove reaction products accumulated inside the shell 110A for cleaning. Through this switching operation, the exhaust paths of the free radicals 136 and the purge gas 138 are switched as described later, so that the exhaust mechanism 132 in the shell 110A and the exhaust path from the outlet of the exhaust mechanism 132 to the exhaust port 133 can be effectively cleaned.

[0091] Next, the cleaning operation for removing the reaction products accumulated in the housing 110A will be described. When performing the cleaning for removing the reaction products accumulated in the housing 110A, the process gas fed from the air inlet 101 is stopped. In addition, in order to more effectively remove the reaction products in the housing 110A, the cleaning is performed in two steps: cleaning of the exhaust mechanism 132 in the housing 110A and cleaning of the exhaust path from the outlet of the exhaust mechanism 132 to the exhaust port 133.

[0092] First, when cleaning the upstream side of the exhaust mechanism 132 in the housing 110A, the exhaust switching valve 202A is switched to open and the exhaust switching valve 202B is switched to close under the control of the control device 200, so that the intermediate port 112 becomes open and the exhaust port 133 becomes closed. Figure 1Then, the on-off valve 140A is opened, and the radicals 136 are supplied from the radical supply mechanism 135 into the housing 110A via the radical supply port 134A, and the purge gas 138 is supplied from the purge gas supply mechanism 137 into the housing 110A via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven to match the supply of the radicals 136 from the radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the radicals 136 and the purge gas 138 supplied into the housing 110A are sucked through the intermediate port 112 and discharged to the outside of the housing 110A.

[0093] Furthermore, the free radicals 136 supplied into the housing 110A activate and decompose / remove the reaction products accumulated inside the housing 110A while flowing inside the housing 110A, and are discharged to the outside of the housing 110A together with the reaction products and the purge gas 138 and processed. In addition, the purge gas 138 supplied from the purge gas supply port 139 on the upstream side (the air intake port 101 side) inside the housing 110A and discharged to the outside of the housing 110A from the intermediate port 112 while flowing together with the free radicals 136, when the free radicals 136 flow inside the housing 110A, guides the free radicals 136 to the intermediate port 112 while riding on the flow of the purge gas 138, and prevents the free radicals 136 from flowing to the air intake port 101 side over a predetermined height portion inside the housing 110A together with the reaction products. That is, the reaction product after the decomposition of the radical 136 is prevented from flowing to the turbomolecular pump mechanism 301 and is accumulated on the upstream side of the turbomolecular pump mechanism 301 .

[0094] Thus, the reaction product accumulated on the exhaust mechanism 132 can be effectively decomposed by the radicals 136 , and the decomposed gas can be discharged to the outside of the housing 110A from the intermediate port 112 .

[0095] In addition, during the cleaning operation of the exhaust mechanism 132, the amount of purge gas 138 flowing from the purge gas supply mechanism 137 into the shell 110A is approximately 1000 sccm, the amount of free radicals 136 flowing from the free radical supply mechanism 135 into the shell 110A is approximately 50 sccm, and the supply power in the free radical supply mechanism 135 is approximately 300 watts (W).

[0096] Next, when cleaning the exhaust path from the outlet of the exhaust mechanism 132 in the shell 110A to the exhaust port 133, the exhaust switching valve 202A is switched to closed, the exhaust switching valve 202B is switched to open, the intermediate port 112 becomes closed, and the exhaust port 133 becomes open under the control of the control device 200. Figure 2Then, the on-off valve 140A is opened, and the radicals 136 are supplied from the radical supply mechanism 135 into the housing 110A via the radical supply port 134A, and the purge gas 138 is supplied from the purge gas supply mechanism 137 into the housing 110A via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven to match the supply of the radicals 136 from the radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the radicals 136 and the purge gas 138 supplied into the housing 110A are sucked through the exhaust port 133 and discharged to the outside of the housing 110A. In addition, during the cleaning operation of the exhaust mechanism 132 on the downstream side, the amount of purge gas 138 flowing from the purge gas supply mechanism 137 into the shell 110A is approximately 50 sccm, the amount of free radicals 136 flowing from the free radical supply mechanism 135 into the shell 110A is approximately 50 sccm, and the supplied power is approximately 300 watts (W).

[0097] Furthermore, the free radicals 136 supplied into the housing 110A activate and decompose / remove the reaction products accumulated inside the housing 110A while flowing inside the housing 110A, and are discharged to the outside of the housing 110A together with the reaction products and the purge gas 138 and processed. In addition, when the downstream side (thread groove pump mechanism part 302 side) of the exhaust mechanism 132 is cleaned, the purge gas 138 is also supplied from the purge gas supply port 139 on the upstream side in the housing 110A, and flows from the exhaust port 133 to the outside of the housing 110A together with the free radicals 136 and is discharged. When the free radicals 136 flow inside the housing 110A, the purge gas 138 guides the free radicals 136 to the exhaust port 133 by riding on the flow of the purge gas 138, and prevents the free radicals 136 from flowing to the air intake port 101 side over a predetermined height portion inside the housing 110A together with the reaction products and dust.

[0098] Therefore, in the turbomolecular pump 100A of the first embodiment thus constructed, when removing the reaction products accumulated inside the housing 110A, the free radicals 136 are supplied into the housing 110A from the free radical supply port 134A provided between the air intake port 101 and the exhaust port 133, so that the supplied free radicals 136 are distributed throughout the entire portion to be cleaned inside the housing 110A, and the accumulated reaction products can be activated and effectively removed. In particular, by performing cleaning separately in the exhaust mechanism 132 and in the exhaust path from the outlet of the exhaust mechanism 132 to the exhaust port 133, the free radicals 136 can be kept from contacting the surfaces of other components that do not need to be cleaned as much as possible, and the activity of the free radicals 136 can be effectively cleaned in a shorter path without losing it. Thus, even a small number of free radical generating devices (free radical supply mechanisms 135) can effectively remove the reaction products, so that the cost of cleaning parts and the operating cost of the cleaning system inside the turbomolecular pump 100A can be reduced.

[0099] Furthermore, during cleaning of the interior of the housing 110A in the turbomolecular pump 100A of the first embodiment, when the purge gas 138 and the free radicals 136 are discharged from the intermediate port 112, in order to reliably prevent the decomposed gas from flowing to the air intake port 101 of the housing 110A, an on-off valve may be provided at the upper portion of the air intake port 101, and the on-off valve may be closed during cleaning.

[0100] In addition, during the cleaning operation, the exhaust mechanism 132 may be rotated at a low speed of about half of the rated speed, i.e., about 13500 rpm. If the exhaust mechanism 132 is rotated at a low speed, the situation where the unreacted free radicals 136 are discharged from the intermediate port 112 is reduced, and the generated free radicals 136 can be effectively utilized. In addition, if the rotation speed of the exhaust mechanism 132 is gradually reduced while cleaning, it is possible to effectively clean from the vicinity of the exhaust port 133 to the air intake port 101. On the other hand, if the rotation speed of the exhaust mechanism 132 is too high, it becomes difficult for the unreacted free radicals 136 to reach the upstream side. Therefore, when the cleaning effect on the upstream side in the housing 110A is low, the rotation speed of the rotating body 103 constituting a part of the exhaust mechanism can be slightly reduced. In addition, in order to further improve the cleaning effect on the upstream side, the rotating body 103 constituting a part of the exhaust mechanism can also be reversely rotated.

[0101] Figure 6 It means that Figure 1 and Figure 2 FIG. 1 is a diagram of a turbomolecular pump 100B according to a second embodiment in which a portion of the turbomolecular pump 100A is deformed. Figure 1 and Figure 2The turbomolecular pump 100A shown in the figure is provided with an on-off valve 140A on the outside of the housing 110A for controlling the supply of radicals 136 from the radical supply mechanism 135. Figure 6 The turbomolecular pump 100B of the second embodiment shown in the figure is provided with a radical supply port 134B for receiving the radical 136 supplied from the radical supply mechanism 135 and an on-off valve 140B for controlling the opening and closing of the radical supply port 134B in the housing 110B, and the other structures and effects are the same as those of the turbomolecular pump 100A of the first embodiment. Therefore, in the following description, the on-off valve 140B is used for the turbomolecular pump 100A of the first embodiment. Figure 1 and Figure 2 The same components of the turbomolecular pump 100A of the first embodiment shown are given the same reference numerals and their description is omitted, and only the parts with different structures are described. Figure 6 The housing 110B shown in FIG. 1 corresponds to Figure 1 and Figure 2 The housing 110A shown in FIG. 10A, in addition, the radical supply port 134B also corresponds to Figure 1 and Figure 2 The radical supply port 134A is shown in FIG.

[0102] exist Figure 6 In the turbomolecular pump 100B of the second embodiment shown, a radical supply port 134B is provided inside the base portion 129 in the housing 110B, and an on-off valve 140B for opening and closing the radical supply port 134B is also provided in the base portion 129 so that a part (valve body 142) of the on-off valve 140B protrudes. The on-off valve 140B is, for example, an electromagnetically operated valve. Furthermore, if the valve body 142 protrudes from the on-off valve 140B by electromagnetic operation, the valve body 142 blocks and closes the radical supply port 134B, thereby preventing the radical 136 from the radical supply mechanism 135 from flowing into the housing 110B via the radical supply port 134B. In addition, the process gas flowing inside the housing 110B is also prevented from flowing into the radical supply mechanism 135. On the contrary, if the valve body 142 is pulled in the direction away from the radical supply port 134B (the main body side of the opening and closing valve 140B) by electromagnetic operation, the radical supply port 134B opens, and the radical 136 from the radical supply mechanism 135 flows into the interior of the shell 110B through the radical supply port 134B.

[0103] Next, the operation of the turbomolecular pump 100B of the second embodiment in the case of removing the reaction products accumulated inside the housing 110B and performing cleaning will be described. In this case, when cleaning is performed to remove the reaction products accumulated inside the housing 110B, the process gas sent from the air intake port 101 is stopped. In addition, in order to more effectively remove the reaction products in the housing 110B, this cleaning is divided into two cleanings, namely, cleaning of the exhaust mechanism 132 in the housing 110B and cleaning of the exhaust path from the outlet of the exhaust mechanism 132 to the exhaust port 133.

[0104] First, when cleaning is performed in the exhaust mechanism 132 in the housing 110B, the exhaust switching valve 202A is switched to open, the exhaust switching valve 202B is switched to close, the intermediate port 112 is opened, and the exhaust port 133 is closed by the control of the control device 200. Then, the valve body 142 of the on-off valve 140B is opened, the radicals 136 are supplied from the radical supply mechanism 135 to the inside of the housing 110B via the radical supply port 134B, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the inside of the housing 110B via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven in accordance with the supply of the radicals 136 from the radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the radicals 136 and the purge gas 138 supplied to the inside of the housing 110B are sucked through the intermediate port 112 and discharged to the outside of the housing 110B.

[0105] Furthermore, the free radicals 136 supplied into the housing 110B activate and decompose / remove the reaction products accumulated inside the housing 110B while flowing inside the housing 110B, and are discharged to the outside of the housing 110B together with the reaction products and the purge gas 138 and processed. In addition, the purge gas 138 supplied from the purge gas supply port 139 on the upstream side (the air intake port 101 side) inside the housing 110B and flowing from the intermediate port 112 to the outside of the housing 110B together with the free radicals 136, when the free radicals 136 flow inside the housing 110B, is guided to the intermediate port 112 by the flow of the purge gas 138, and the free radicals 136 are prevented from flowing to the air intake port 101 side beyond a predetermined height position inside the housing 110B together with the reaction products.

[0106] Thus, the reaction product accumulated on the exhaust mechanism 132 can be effectively decomposed by the radicals 136 , and the decomposed gas can be discharged to the outside of the housing 110B from the intermediate port 112 .

[0107] In addition, during the cleaning of the exhaust mechanism 132, the amount of the purge gas 138 flowing from the purge gas supply mechanism 137 to the interior of the shell 110B is approximately 1000 sccm, the amount of free radicals 136 flowing from the free radical supply mechanism 135 to the interior of the shell 110B is approximately 50 sccm, and the supply power in the free radical supply mechanism 135 is approximately 300 watts (W).

[0108] Next, a case where the exhaust path from the outlet of the exhaust mechanism 132 in the housing 110B to the exhaust port 133 is cleaned is described. When cleaning the downstream side, the exhaust switching valve 202A is switched to close, the exhaust switching valve 202B is switched to open, the intermediate port 112 is closed, and the exhaust port 133 is opened by the control of the control device 200. Then, the on-off valve 140B is opened, the radical 136 is supplied from the radical supply mechanism 135 to the inside of the housing 110B via the radical supply port 134B, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the inside of the housing 110B via the purge gas supply port 139. Furthermore, the suction / exhaust mechanism 201 is driven in accordance with the supply of the radicals 136 from the radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the radicals 136 and the purge gas 138 supplied to the inside of the housing 110B are sucked and exhausted to the outside of the housing 110B through the exhaust port 133. In addition, during the cleaning operation of the exhaust path from the outlet of the exhaust mechanism 132 to the exhaust port 133, the amount of the purge gas 138 flowing from the purge gas supply mechanism 137 to the inside of the housing 110B is about 50 sccm, the amount of the radicals 136 flowing from the radical supply mechanism 135 to the inside of the housing 110B is about 50 sccm, and the supplied power is about 300 watts (W).

[0109] Furthermore, the free radicals 136 supplied into the housing 110B activate and decompose / remove the reaction products accumulated inside the housing 110B while flowing inside the housing 110B, and are discharged to the outside of the housing 110B together with the reaction products and the purge gas 138 and processed. Furthermore, when cleaning the downstream side of the exhaust mechanism 132, the purge gas 138 supplied from the upstream side purge gas supply port 139 in the housing 110B and flowing from the exhaust port 133 to the outside of the housing 110B together with the free radicals 136 also guides the free radicals 136 to the exhaust port 133 while the free radicals 136 flow inside the housing 110B, thereby preventing the free radicals 136 from flowing to the air intake port 101 side beyond a predetermined height position inside the housing 110B together with the reaction products.

[0110] Therefore, in the turbomolecular pump 100B of the second embodiment thus constructed, when removing the reaction products accumulated inside the housing 110B, the free radicals 136 are supplied to the inside of the housing 110B from the free radical supply port 134B provided between the air intake port 101 and the exhaust port 133, so that the supplied free radicals 136 are distributed throughout the entire portion to be cleaned inside the housing 110B, and the accumulated reaction products can be activated and effectively removed. In particular, by performing cleaning separately in the exhaust mechanism 132 and in the exhaust path from the outlet of the exhaust mechanism 132 to the exhaust port 133, the free radicals 136 can be kept from contacting the surfaces of other components that do not need to be cleaned as much as possible, and the activity of the free radicals 136 can be effectively cleaned in a shorter path without losing it. Thus, even with a small number of free radical generating devices (free radical supply mechanisms 135), the reaction products can be effectively removed, and the reduction of the cost of cleaning parts and the reduction of the operating cost in the cleaning system inside the turbomolecular pump 100B can be achieved.

[0111] Figure 7 It means that Figure 1 and Figure 2 FIG. 1 is a diagram of a turbomolecular pump 100C according to a third embodiment in which a portion of the turbomolecular pump 100A is deformed. Figure 1 and Figure 2 The turbomolecular pump 100A shown in the figure is provided with a radical supply port 134 between the air intake port 101 and the air exhaust port 133. Figure 7 The turbomolecular pump 100C of the third embodiment shown in FIG. 1 supplies radicals 136 from the exhaust port 133, and the other structures and effects are the same as those of the turbomolecular pump 100A of the first embodiment. Figure 1 and Figure 2 The same components of the turbomolecular pump 100A of the first embodiment shown are given the same reference numerals and their description is omitted, and only the parts with different structures are described. Figure 7 The housing 110C shown in FIG. 1 corresponds to Figure 1 and Figure 2 The housing 110A shown in FIG. 10A, in addition, the radical supply port 134C also corresponds to Figure 1 and Figure 2 The radical supply port 134A is shown in FIG.

[0112] exist Figure 7 In the turbo molecular pump 100C of the third embodiment shown in FIG. 1 , the intermediate port 112 is provided corresponding to the substantially middle portion of the exhaust mechanism 132 in the axial direction. Figure 7As shown, the intermediate port 112 is arranged roughly corresponding to the upstream part (turbomolecular pump mechanism part 301) and the downstream part (thread groove pump mechanism part 302) in the exhaust mechanism 132, the upstream part has a plurality of rotating blades 102 arranged in multiple layers in the axial direction, and a plurality of fixed blades 123 arranged between the plurality of rotating blades 102, and the downstream part has a cylindrical part 102m, and a thread groove 131a on the inner peripheral surface of a threaded spacer 131 opposite to the outer peripheral surface of the cylindrical part 102m.

[0113] In addition, the suction / exhaust mechanism 201 is connected to the intermediate port 112 of the turbomolecular pump 100B via the on-off valve 202C. The suction / exhaust mechanism 201 has a suction pump that forcibly sucks / exhausts the free radicals 136 and the purge gas 138 in the housing 110C to the outside of the housing 110C via the intermediate port 112 during cleaning. The on-off valve 202C here is a valve that is controlled to be opened and closed by the control device 200. Moreover, the on-off valve 202C is controlled to be open by the control device 200 when cleaning is performed to remove the reaction products accumulated in the housing 110C using the free radicals 136 and the purge gas 138, and the intermediate port 112 is connected to the suction / exhaust mechanism 201, and the gas in the housing 110C is sucked / exhausted to the outside of the housing 110C, so that the exhaust mechanism 132 and the like in the interior of the housing 110C can be effectively cleaned.

[0114] Next, the operation of cleaning in which the reaction products accumulated inside the housing 110C are removed will be described. When cleaning the exhaust mechanism 132 and the like inside the housing 110C, the on-off valve 202C is switched from closed to open by the control of the control device 200. Then, the three-way valve 140C is switched, and the free radical 136 is supplied from the free radical supply mechanism 135 to the housing 110C via the exhaust port 133, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the housing 110C via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven to match the supply of the free radical 136 from the free radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the free radical 136 and the purge gas 138 supplied to the housing 110C are discharged to the outside of the housing 110C via the intermediate port 112.

[0115] Furthermore, the free radicals 136 supplied into the housing 110C activate and decompose / remove the reaction products accumulated inside the housing 110C while flowing inside the housing 110C, and are discharged to the outside of the housing 110C together with the reaction products and the purge gas 138 and processed. In addition, the purge gas 138 supplied from the purge gas supply port 139 on the upstream side (the air inlet 101 side) inside the housing 110C and flowing from the intermediate port 112 to the outside of the housing 110C together with the free radicals 136, when the free radicals 136 flow inside the housing 110C, is guided to the intermediate port 112 by the flow of the purge gas 138, and the free radicals 136 are prevented from flowing to the air inlet 101 side beyond a predetermined height position inside the housing 110A together with the reaction products. Therefore, in the structure of the third embodiment, the amount of the purge gas 138 flowing from the purge gas supply mechanism 137 into the housing 110C and the amount of the radicals 136 flowing from the radical supply mechanism 135 into the housing 110C are adjusted while being balanced, and the flow of the radicals 136 toward the upstream side of the housing 110C together with the reaction products is controlled. In addition, in the adjustment of the height positions of the purge gas 138 and the radicals 136, the cleaning range in the housing 110C is set, and cleaning is performed within the set range.

[0116] Figure 8 It means that Figure 1 and Figure 2 FIG. 1 is a diagram of a turbomolecular pump 100D according to a fourth embodiment in which a portion of the turbomolecular pump 100A is deformed. Figure 1 and Figure 2 In the turbomolecular pump 100A shown in the figure, the radical supply port 134A is located at a height position substantially the same as that of the exhaust port 133 in the axial direction of the exhaust mechanism 132. Figure 8 The turbomolecular pump 100D of the fourth embodiment shown in the figure sets the radical supply port 134D at a position above the exhaust port 133 and roughly corresponding to the downstream portion (thread groove pump mechanism portion 302) in the exhaust mechanism 132, the downstream portion having a cylindrical portion 102m and a thread groove 131a on the inner peripheral surface of the threaded spacer 131 facing the outer peripheral surface of the cylindrical portion 102m. The other structures and effects are the same as those of the turbomolecular pump 100A of the first embodiment. Therefore, in the following description, the downstream portion is not described in detail. Figure 1 and Figure 2 The same components of the turbomolecular pump 100A of the first embodiment shown are given the same reference numerals and their description is omitted, and only the parts with different structures are described. Figure 8 The housing 110D shown in FIG. 1 corresponds to Figure 1 and Figure 2The housing 110A shown in FIG. 110A, in addition, the radical supply port 134D also corresponds to Figure 1 and Figure 2 The radical supply port 134A is shown in FIG.

[0117] Figure 8 The radical supply port 134D in the turbomolecular pump 100D of the fourth embodiment shown is located above the exhaust port 133 and approximately corresponding to the downstream portion (thread groove pump mechanism portion 302) in the exhaust mechanism 132, and the outer peripheral surface of the threaded spacer 131 is set to penetrate the housing 110D and the threaded spacer 131, and the downstream portion has a cylindrical portion 102m and a thread groove 131a on the inner peripheral surface of the threaded spacer 131 opposite to the outer peripheral surface of the cylindrical portion 102m.

[0118] Next, the operation of the turbomolecular pump 100D of the fourth embodiment in the case of removing the reaction products accumulated inside the housing 110D for cleaning is described. In this case, too, when cleaning is performed to remove the reaction products accumulated inside the housing 110D, the process gas fed from the air intake port 101 is stopped.

[0119] Furthermore, in the turbomolecular pump 100D of the fourth embodiment, when cleaning the upstream side of the radical supply port 134D, the exhaust switching valve 202A is switched to open, the exhaust switching valve 202B is switched to close, the intermediate port 112 is opened, and the exhaust port 133 is closed, under the control of the control device 200. Then, the on-off valve 140A is opened, the radicals 136 are supplied from the radical supply mechanism 135 to the housing 110D via the radical supply port 134D, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the housing 110D via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven to match the supply of free radicals 136 from the free radical supply mechanism 135 and the supply of purge gas 138 from the purge gas supply mechanism 137, and the free radicals 136 and purge gas 138 supplied into the shell 110D are sucked through the intermediate port 112 and discharged to the outside of the shell 110D.

[0120] Furthermore, the free radicals 136 supplied into the housing 110D activate and decompose / remove the reaction products accumulated inside the exhaust mechanism 132 while flowing inside the housing 110D, and are discharged to the outside of the housing 110D together with the reaction products and the purge gas 138 and processed. In addition, the purge gas 138 supplied from the purge gas supply port 139 on the upstream side (the air intake port 101 side) inside the housing 110D and flowing from the intermediate port 112 to the outside of the housing 110D together with the free radicals 136, when the free radicals 136 flow inside the housing 110D, is guided to the intermediate port 112 by the flow of the purge gas 138, and the free radicals 136 are prevented from flowing to the air intake port 101 side beyond a predetermined height position inside the housing 110D together with the reaction products.

[0121] Thus, the reaction products accumulated over a wide range can be effectively decomposed by free radicals 136 at a predetermined height position from the downstream side of the shell 110D (exhaust port 133) to the upstream side beyond the intermediate port 112, and the decomposed gas can be discharged from the intermediate port 112 to the outside of the shell 110D.

[0122] In addition, during the cleaning of the exhaust mechanism 132 on the upstream side, the amount of purge gas 138 flowing from the purge gas supply mechanism 137 to the inside of the shell 110D is approximately 1000 sccm, the amount of free radicals 136 flowing from the free radical supply mechanism 135 to the inside of the shell 110A is approximately 50 sccm, and the supply power in the free radical supply mechanism 135 is approximately 300 watts (W).

[0123] Next, in the case of intensively cleaning the range downstream of the radical supply port 134D, the exhaust switching valve 202A is switched to close, the exhaust switching valve 202B is switched to open, the intermediate port 112 is closed, and the exhaust port 133 is opened by the control of the control device 200. Then, the on-off valve 140A is opened, the radicals 136 are supplied from the radical supply mechanism 135 to the inside of the housing 110D via the radical supply port 134D, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the inside of the housing 110D via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven in accordance with the supply of the radicals 136 from the radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the radicals 136 and the purge gas 138 supplied to the inside of the housing 110D are sucked through the exhaust port 133 and discharged to the outside of the housing 110D. In addition, during the cleaning of the exhaust mechanism 132 on the downstream side, the amount of purge gas 138 flowing from the purge gas supply mechanism 137 to the inside of the shell 110D is approximately 50 sccm, the amount of free radicals 136 flowing from the free radical supply mechanism 135 to the inside of the shell 110B is approximately 50 sccm, and the supplied power is approximately 300 watts (W).

[0124] Furthermore, the free radicals 136 supplied to the interior of the housing 110D activate and decompose / remove the reaction products accumulated in the interior of the housing 110D while flowing in the interior of the housing 110D, and are discharged to the outside of the housing 110D together with the reaction products and the purge gas 138 and processed. In addition, when the downstream side (thread groove pump mechanism 302) of the exhaust mechanism 132 is cleaned, the purge gas 138 supplied from the upstream side purge gas supply port 139 in the housing 110D and flowing to the outside of the housing 110D together with the free radicals 136 from the exhaust port 133 also guides the free radicals 136 to the exhaust port 133 while the free radicals 136 flow in the housing 110D, thereby preventing the free radicals 136 from flowing to the air intake port 101 side beyond the predetermined height position in the housing 110B together with the reaction products.

[0125] Therefore, in the turbomolecular pump 100D of the fourth embodiment thus constructed, when removing the reaction products accumulated in the housing 110D, the free radicals 136 are supplied into the housing 110D from the free radical supply port 134D provided between the air intake port 101 and the exhaust port 133, so that the supplied free radicals 136 are distributed throughout the entire portion to be cleaned in the housing 110D, and the accumulated reaction products can be activated and effectively removed. In particular, by performing cleaning separately at the upstream side of the free radical supply port 134D and the downstream side of the free radical supply port 134D, the free radicals 136 can be cleaned as little as possible without contacting the surfaces of other components that do not need to be cleaned, and without losing the activity of the free radicals 136, along a short path. Thus, even a small number of free radical generating devices (free radical supply mechanisms 135) can effectively remove the reaction products, so that both the reduction in the cost of cleaning parts and the reduction in the operating cost in the cleaning system inside the turbomolecular pump 100D can be suppressed.

[0126] Fig. 9 It means that Figure 1 and Figure 2 FIG. 1 is a diagram of a turbomolecular pump 100E according to a fifth embodiment in which a portion of the turbomolecular pump 100A is deformed. Figure 1 and Figure 2 , Figure 6 , Figure 7 , Figure 8 The structures of the thread groove pump mechanism 302 of the turbomolecular pumps 100A, 100B, 100C, and 100D shown in the figures are all Holweg type pump mechanisms. Fig. 9 The turbomolecular pump 100E of the fifth embodiment shown in the figure is a case where a Siegband type pump mechanism is used, and the other structures and effects are the same as those of the turbomolecular pump 100A of the first embodiment. Figure 1 and Figure 2 The same components of the turbomolecular pump 100A of the first embodiment shown are given the same reference numerals and their description is omitted, and only the parts with different structures are described. Fig. 9 The housing 110E shown in FIG. 1 corresponds to Figure 1 and Figure 2 The housing 110A shown in FIG. 10A, in addition, the radical supply port 134E also corresponds to Figure 1 and Figure 2 The radical supply port 134A is shown in FIG.

[0127] The thread groove pump mechanism 302 is configured as a Sigband type pump mechanism. Fig. 9The screw groove pump mechanism 302 in the turbomolecular pump 100E shown has a rotating disc 302A and a fixed disc 302B that are axially opposed to each other. Moreover, the screw groove 302F as a spiral groove is formed on both sides of the fixed disc 302B that is opposed to the rotating disc 302A, and the screw groove 302F is provided with a spiral mountain portion 302D and a spiral valley portion 302E.

[0128] also, Fig. 9 The intermediate port 112 in the turbomolecular pump 100E shown is set near the boundary between the turbomolecular pump mechanism 301 and the thread groove pump mechanism 302 which is a sigban type pump mechanism, and is set to be in a state of penetrating into the housing 110A. On the other hand, the free radical supply port 134E in the turbomolecular pump 100E is located above the exhaust port 133 and roughly corresponding to the lower side of the downstream part in the exhaust mechanism 132 (the lower surface of the rotating circular plate 302A), and is set to be in a state of penetrating the housing 110E.

[0129] Next, the operation of the turbomolecular pump 100E of the fifth embodiment for cleaning by removing the reaction products accumulated inside the housing 110E is described. In this case, also in the cleaning operation of removing the reaction products accumulated inside the housing 110E, the process gas fed from the air intake port 101 is stopped.

[0130] Furthermore, in the turbomolecular pump 100E of the fifth embodiment, when cleaning is performed over the range from the downstream side to the upstream side in the housing 110E, the exhaust switching valve 202A is switched to open, the exhaust switching valve 202B is switched to close, the intermediate port 112 is opened, and the exhaust port 133 is closed by the control of the control device 200. Then, the on-off valve 140A is opened, the radical 136 is supplied from the radical supply mechanism 135 to the housing 110E via the radical supply port 134E, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the housing 110E via the purge gas supply port 139. In addition, the suction / exhaust mechanism 201 is driven to match the supply of free radicals 136 from the free radical supply mechanism 135 and the supply of purge gas 138 from the purge gas supply mechanism 137, and the free radicals 136 and purge gas 138 supplied into the shell 110E are sucked through the intermediate port 112 and discharged to the outside of the shell 110E.

[0131] Furthermore, the free radicals 136 supplied into the housing 110E activate and decompose / remove the reaction products accumulated inside the housing 110E while flowing inside the housing 110E, and are discharged to the outside of the housing 110E together with the reaction products and the purge gas 138 and processed. In addition, the purge gas 138 supplied from the purge gas supply port 139 on the upstream side (the air intake port 101 side) inside the housing 110E and flowing from the intermediate port 112 to the outside of the housing 110E together with the free radicals 136, when the free radicals 136 flow inside the housing 110B, guides the free radicals 136 to the intermediate port 112 by riding on the flow of the purge gas 138, and prevents the free radicals 136 from flowing to the air intake port 101 side beyond a predetermined height position inside the housing 110E together with the reaction products.

[0132] Thus, the reaction products accumulated over a wide range can be effectively decomposed by free radicals 136 at a predetermined height position from the downstream side of the shell 110E (exhaust port 133) to the upstream side beyond the intermediate port 112, and the decomposed gas can be discharged from the shell 110E from the intermediate port 112.

[0133] In addition, during the cleaning of the exhaust mechanism 132 on the upstream side, the amount of purge gas 138 flowing from the purge gas supply mechanism 137 to the inside of the shell 110E is approximately 1000 sccm, the amount of free radicals 136 flowing from the free radical supply mechanism 135 to the inside of the shell 110E is approximately 50 sccm, and the supply power in the free radical supply mechanism 135 is approximately 300 watts (W).

[0134] Next, when only the downstream side of the exhaust mechanism 132 in the housing 110E (in this example, the part of the Sigband type pump mechanism) is cleaned intensively, the exhaust switching valve 202A is switched to close, the exhaust switching valve 202B is switched to open, the intermediate port 112 is closed, and the exhaust port 133 is opened by the control of the control device 200. Then, the on-off valve 140A is opened, the radical 136 is supplied from the radical supply mechanism 135 to the housing 110E via the radical supply port 134E, and the purge gas 138 is supplied from the purge gas supply mechanism 137 to the housing 110D via the purge gas supply port 139. Furthermore, the suction / exhaust mechanism 201 is driven in accordance with the supply of the radicals 136 from the radical supply mechanism 135 and the supply of the purge gas 138 from the purge gas supply mechanism 137, and the radicals 136 and the purge gas 138 supplied into the housing 110E are sucked and exhausted to the outside of the housing 110E through the exhaust port 133. In the cleaning of the exhaust mechanism 132 on the downstream side, the amount of the purge gas 138 flowing from the purge gas supply mechanism 137 into the housing 110E is about 50 sccm, the amount of the radicals 136 flowing from the radical supply mechanism 135 into the housing 110E is about 50 sccm, and the supplied power is about 300 watts (W).

[0135] Furthermore, the free radicals 136 supplied into the housing 110E activate and decompose / remove the reaction products accumulated inside the housing 110E while flowing inside the housing 110E, and are discharged to the outside of the housing 110E together with the reaction products and the purge gas 138 and processed. Furthermore, when the downstream side of the exhaust mechanism 132 (in this example, the part of the sigban type pump mechanism) is cleaned, the purge gas 138 supplied from the purge gas supply port 139 on the upstream side of the housing 110E and discharged from the exhaust port 133 to the outside of the housing 110E together with the free radicals 136 also guides the free radicals 136 to the exhaust port 133 while the free radicals 136 flow inside the housing 110E, thereby preventing the free radicals 136 from flowing to the air intake port 101 side beyond a predetermined height position inside the housing 110E together with the reaction products.

[0136] Therefore, in the turbomolecular pump 100E based on the fifth embodiment configured in this way, when removing the reaction products accumulated in the housing 110E, the free radicals 136 are supplied into the housing 110E from the free radical supply port 134E provided between the air intake port 101 and the exhaust port 133, so that the supplied free radicals 136 are distributed throughout the entire portion to be cleaned in the housing 110E, and the accumulated reaction products can be activated and effectively removed. In particular, by performing the cleaning separately on the upstream side and the downstream side of the exhaust mechanism 132, the free radicals 136 can be cleaned as little as possible without contacting the surfaces of other components that do not need to be cleaned, and the activity of the free radicals 136 can be lost. Thus, even a small number of free radical generating devices (free radical supply mechanisms 135) can effectively remove the reaction products, and both the reduction in the cost of cleaning parts and the reduction in the operating cost in the system for cleaning the interior of the turbomolecular pump 100E can be suppressed.

[0137] In addition, the present invention can be variously modified and combined without departing from the spirit of the present invention, and the present invention naturally relates to the configurations of such modifications and combinations.

[0138] Furthermore, in each embodiment, the radical supply mechanism 135 is described using a structure in which the radical supply mechanism 135 is provided outside the turbomolecular pumps 100A to 100E, but the radical generator may be provided so as to be built in the housings 110A to 100E.

[0139] Description of Reference Numerals

[0140] 100A: Turbomolecular pump

[0141] 100B: Turbomolecular pump

[0142] 100C: Turbomolecular pump

[0143] 100D: Turbomolecular pump

[0144] 100E: Turbomolecular pump

[0145] 101: Intake

[0146] 102: Rotating blades

[0147] 102m: Cylinder

[0148] 103: Rotating body (exhaust mechanism)

[0149] 110A: Shell

[0150] 110B: Shell

[0151] 110C: Shell

[0152] 110D: Housing

[0153] 110E: Shell

[0154] 112: Middle port

[0155] 113: Rotor shaft

[0156] 123: Fixed blade

[0157] 123a: Fixed blade

[0158] 123b: Fixed blade

[0159] 123c: Fixed blade

[0160] 125: Fixed blade spacer

[0161] 127: Outer cylinder

[0162] 129: Base

[0163] 131: Threaded spacer

[0164] 131a: thread groove

[0165] 132: Exhaust mechanism

[0166] 133: Exhaust port

[0167] 134A: Free radical supply port

[0168] 134B: Free radical supply port

[0169] 134C: Free radical supply port

[0170] 134D: Free radical supply port

[0171] 134E: Free radical supply port

[0172] 135: Free radical supply mechanism

[0173] 136: Free Radicals

[0174] 137: Purge gas supply mechanism

[0175] 138: Purge gas

[0176] 139: Purge gas supply port

[0177] 140A: On / Off Valve

[0178] 140B: On / off valve

[0179] 140C: Three-way valve

[0180] 200: Control device

[0181] 201: Suction / exhaust mechanism

[0182] 202A: Exhaust switching valve

[0183] 202B: Exhaust switching valve

[0184] 202C: On / off valve

[0185] 301: Turbomolecular pump mechanism

[0186] 302: Thread groove pump mechanism

[0187] 302A: Rotating circular plate

[0188] 302B: Fixed round plate

[0189] 302D: Vortex Mountain

[0190] 302E: Spiral valley

[0191] 302F: thread groove

Claims

1. A vacuum pump comprising a housing having an air intake port and an air exhaust port, and an exhaust mechanism disposed inside the housing, characterized in that: have: A radical supply port is disposed near the exhaust outlet of the exhaust mechanism and is provided to penetrate into the housing; and The radical supply mechanism supplies radicals into the housing from the radical supply port, and causes the supplied radicals to flow to a portion where the reaction product is accumulated in the exhaust mechanism.

2. The vacuum pump according to claim 1, characterized in that An intermediate port for discharging the radicals to the outside of the housing is provided between the air intake port and the radical supply port.

3. The vacuum pump according to claim 2, characterized in that have: a suction / exhaust mechanism capable of sucking the free radicals supplied into the housing through the exhaust port or the intermediate port and exhausting them to the outside of the housing; and The exhaust switching valve can switch the exhaust path of the radicals to either the exhaust port or the intermediate port.

4. The vacuum pump according to claim 1, characterized in that At least a part of the exhaust mechanism is a turbomolecular pump mechanism including a rotating body having a plurality of rotating blades arranged in multiple layers in the axial direction, and a plurality of stationary blades disposed between the plurality of rotating blades.

5. The vacuum pump according to claim 1, characterized in that At least a portion of the exhaust mechanism is a Sigband pump mechanism having a rotating circular plate, a fixed circular plate, and a spiral groove provided at least a portion of the facing surfaces of the rotating circular plate and the fixed circular plate.

6. The vacuum pump according to claim 1, characterized in that At least a portion of the exhaust mechanism is a Holweg-type pump mechanism including a rotating cylinder, a fixed cylinder, and a threaded groove provided at least a portion of the facing surfaces of the rotating cylinder and the fixed cylinder.

7. The vacuum pump according to claim 2, characterized in that The exhaust mechanism is composed of at least two of a turbomolecular pump mechanism, a Siegbain pump mechanism, or a Holvik pump mechanism, wherein the turbomolecular pump mechanism has a rotating body having a plurality of rotating blades arranged in a multi-layered manner in the axial direction, and a plurality of fixed blades arranged between the plurality of rotating blades, the Siegbain pump mechanism has a rotating disc, a fixed disc, and a spiral groove provided at least in a portion of the facing surface of the rotating disc and the fixed disc, and the Holvik pump mechanism has a rotating cylinder, a fixed cylinder, and a threaded groove provided at least in a portion of the facing surface of the rotating cylinder and the fixed cylinder; The intermediate port is disposed near a boundary between the adjacent turbomolecular pump mechanisms, the Siegbain pump mechanisms, or the Holweg pump mechanisms.

8. A vacuum exhaust system, characterized in that: have: A vacuum pump comprising a housing having an air intake port and an air exhaust port, an exhaust mechanism disposed inside the housing, and a radical supply port disposed near an exhaust side outlet of the exhaust mechanism and penetrating into the housing; and The radical supply mechanism supplies radicals into the housing from the radical supply port, and supplies the supplied radicals to a portion where the reaction product is accumulated in the exhaust mechanism.

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