JP7481085B2 - Gas transfer device and method of using the gas transfer device - Google Patents

Description

The present invention relates to a gas transfer device and a method for using the gas transfer device.

Among vacuum equipment such as semiconductor manufacturing equipment, there are some that are used with some kind of gas introduced into the vacuum chamber. One example is a dry etching equipment that etches a substrate with a gas such as sulfur hexafluoride introduced into the equipment. Another example is a vacuum sputtering equipment that sputters an object with a gas such as argon introduced into the equipment.

As described above, in a vacuum device that introduces gas into a chamber, the amount of processing of the target object varies depending on the degree of vacuum inside the device (the pressure or concentration of the introduced gas), so it is important to control the degree of vacuum. JP 2007-134428 A (Patent Document 1) discloses a dry etching device that adjusts the gas pressure of sulfur hexafluoride in a plasma chamber by controlling an orifice valve.

JP 2007-134428 A

In the device described in Patent Document 1, gas in the plasma chamber is exhausted from the orifice valve to the outside of the plasma chamber. Therefore, the gas pressure may be low (high vacuum) near the orifice valve, and the gas pressure may be high (low vacuum) far from the orifice valve. Non-uniformity in the vacuum level inside the plasma chamber, especially near the workpiece, may affect the processing accuracy, processing uniformity, and/or processing stability of the dry etching.

This issue is not limited to dry etching equipment. The issue described above exists in general vacuum equipment that introduces gas into a chamber, such as a vacuum sputtering device.

Therefore, one of the objectives of this application is to solve the above-mentioned problems.

This application discloses a gas transfer device for transferring gas, comprising an inner cylinder having at least a cylindrical portion on at least a part thereof and including a stage mounting portion provided on the intake side of the inner cylinder, an outer cylinder having at least a cylindrical portion on at least a part thereof and arranged coaxially with the central axis of the inner cylinder, a rotor blade provided on a gas flow path defined by the inner cylinder and the outer cylinder, the rotor blade configured to be rotatable around the central axis, a stationary blade provided on the gas flow path, and a motor for rotating the rotor blade, the inner cylinder and the outer cylinder being formed hollow, and the gas transfer device further comprising a gas purge port for supplying gas to a space defined by the inner cylinder and the rotor blade.

FIG. 2 is a schematic cross-sectional view of the gas transfer device according to the first embodiment. FIG. 2 is an exploded three-dimensional view of the inner cylinder and other components according to the first embodiment. FIG. FIG. FIG. FIG. 2 is an enlarged cross-sectional view of the periphery of an axial magnetic pole of the gas transfer device shown in FIG. 1 . FIG. 4 is a front view of the axial sensor holder. FIG. 4 is a bottom view of the axial sensor holder. FIG. 13 is a diagram showing the gas transfer device with the stage mounting part removed. FIG. 11 is a schematic cross-sectional view of a gas transfer device according to a second embodiment. FIG. 1 is a front cross-sectional view of a gas transfer device having a touchdown bearing provided at the exhaust side end of a rotor blade. FIG. 13 is a front cross-sectional view of a gas transfer device in which the inner cylinder can be removed together with the bottom plate toward the inside of the processing chamber. 11 is a front cross-sectional view of the gas transfer device of FIG. 10 with the inner cylinder 110 removed together with the bottom plate. FIG. 2 is a diagram showing a gas transfer device in which a stage of stator vanes is located at the most intake side.

First Embodiment
1 is a schematic diagram showing a cross section of a gas transfer device 100 according to the first embodiment. Note that gas transfer device 100 according to the present embodiment is configured symmetrically with respect to a central axis 113, except for a connector 118, an exhaust port 122, a vent port 181 provided in an airflow adjustment baffle plate 180, and a gas purge port 191 provided in a stage mounting portion 114.

The gas transfer device 100 in FIG. 1 is configured to suck in gas from the top of the page and exhaust gas to the bottom of the page. In the following description, the "intake side" refers to the top of the page or the upward direction of the page in FIG. 1, and the "exhaust side" refers to the bottom of the page or the downward direction of the page in FIG. 1. The gas transfer device 100 will be described as being connected to a vacuum device 10. The vacuum device 10 in this example is a dry etching device, and is equipped with a processing chamber 11 (vacuum chamber 11), a process gas supply mechanism 12 and a shower head electrode 13 provided in the processing chamber 11, an AC power source 14, and a cable 15 connected to the AC power source 14. A control device 20 for controlling at least one of the vacuum device 10 and the gas transfer device 100 may also be provided. The vacuum device 10 may be a device such as a CVD device, a vacuum deposition device, or an ashing device, in addition to a dry etching device.

(Regarding the inner and outer cylinders)
The gas transfer device 100 of FIG. 1 includes an inner cylinder 110 and an outer cylinder 120 that is provided outside the inner cylinder 110 and spaced apart from the inner cylinder 110. In the example of FIG. 1, a space between the outer peripheral surface of the inner cylinder 110 and the inner peripheral surface of the outer cylinder 120 forms a gas flow path 130 in the gas transfer device 100. In other words, the inner cylinder 110 and the outer cylinder 120 define the gas flow path 130. The gas transfer device 100 includes an exhaust port 122 for exhausting gas that has passed through the gas flow path 130. In this embodiment, the exhaust port 122 is provided at the bottom of the outer cylinder 120, but the exhaust port 122 may be provided in another part of the outer cylinder 120. The exhaust port 122 may also be provided in another part such as the inner cylinder 110.

The inner cylinder 110 has at least a cylindrical portion 111. The inner cylinder 110 is formed hollow and defines a hollow space 112. The outer cylinder 120 also has at least a cylindrical portion 121 and is formed hollow. The cylindrical portion 121 of the outer cylinder 120 is formed hollow.
1. The cylindrical portion 111 of the nozzle 100 is disposed coaxially with the central axis 113 of the cylindrical portion 111 of the nozzle 100.

The inner cylinder 110 includes a stage mounting portion 114 for mounting the stage 115 at the end of the intake side of the inner cylinder 110. The stage mounting portion 114 may be formed integrally with the inner cylinder 110 or may be formed as a separate part. In this embodiment, the stage mounting portion 114 is a cylindrical, hollow part and is a separate part from the inner cylinder 110. However, the shape of the stage mounting portion 114 is not limited to a cylindrical shape, and can be a shape that corresponds to the shape of the stage 115, for example. The stage mounting portion 114 can also be non-hollow. In this case, the stage mounting portion 114 becomes the closed end of the hollow space 112.

A stage 115 for fixing the substrate 116 is attached to the stage attachment portion 114. Since the stage attachment portion 114 is a part of the inner cylinder 110, it is also possible to express that "the stage 115 is attached to the inner cylinder 110". In this embodiment, the stage 115 is formed in a cylindrical shape in order to fix the circular substrate 116. However, the shape of the stage 115 is not limited to a cylindrical shape, and can be, for example, a shape corresponding to the shape of the substrate 116. Furthermore, the stage 115 forms the closed end of the hollow space 112. The stage 115 is configured to be able to fix the substrate 116, such as a silicon wafer, by including, for example, an electrostatic chuck or the like.

The arrangement of the inner cylinder 110, the outer cylinder 120, the stage attachment portion 114, the stage 115, and the substrate 116 will be described using the exploded view of FIG. 2. However, in FIG. 2, parts other than the inner cylinder 110, the outer cylinder 120, the stage attachment portion 114, the stage 115, the substrate 116, the connector 118, the first bolt 124, and the second bolt 202 are not shown.

2, in this embodiment, the central axes of the outer cylinder 120, the stage mounting portion 114, the stage 115, and the substrate 116 are arranged so as to be coaxial with the central axis 113 of the cylindrical portion 111 of the inner cylinder 110. The bottom of the inner cylinder 110 is provided with first female threaded holes 117 (eight in this example), and the bottom of the outer cylinder 120 is provided with first through holes 123 (eight in this example). In this example, the inner cylinder 110 can be fixed to the outer cylinder 120 by screwing eight first bolts 124 into the first female threaded holes 117 through the first through holes 123. However, the method of fixing the inner cylinder 110 and the outer cylinder 120 is not limited to the above-mentioned method. For example, a bottom plate can be provided between the inner cylinder 110 and the outer cylinder 120, the inner cylinder 110 and the bottom plate can be fixed, and the outer cylinder 120 can be further fixed to the bottom plate. It is also preferable to provide a seal such as an O-ring between the inner cylinder 110 and the outer cylinder 120.

The inner cylinder 110 and the stage mounting part 114 can also be fixed using a second through hole 200 provided in the stage mounting part 114, a second female threaded hole 201 provided on the intake side of the inner cylinder 110, and a second bolt 202. In this case, by providing a countersunk portion in the second through hole 200, it is possible to prevent the head of the second bolt 202 from interfering with the stage 115. The stage mounting part 114 and the stage 115 can also be fixed with bolts. In addition to fixing with bolts, conventionally known fixing methods such as fitting can also be used to fix the various parts together.

Depending on the type of vacuum device 10 to which the gas transfer device 100 is connected, various functions or configurations can be given to the stage 115. For example, if the vacuum device 10 is a dry etching device, an electrode connected to an AC power source 14 may be provided on the stage 115. In addition, for example, a stage drive mechanism or a stage temperature adjustment mechanism can be provided on the stage 115. By storing these elements or wiring connected to these elements in the hollow space 112, the gas transfer device 100 can be made smaller.

(About rotor blades and stator blades)
A moving blade 140 and a stator blade 150 are provided on the gas flow path 130. The moving blade 140 is rotatably disposed on the gas flow path 130. The stator blade 150 is disposed to face the moving blade 140. The moving blade 140 and the stator blade 150 provided on the gas flow path 130 obstruct the flow of gas molecules on the gas flow path 130 and reduce the piping conductance of the gas flow path 130. By reducing the piping conductance, it becomes possible to uniformly maintain the gas supplied from the process gas supply mechanism 12 to the inside of the vacuum apparatus 10 inside the processing chamber 11.

The moving blade 140 is a member that rotates or is rotated at high speed. In addition, the gas transfer device 100 according to the embodiment has a hollow space 112. Therefore, the diameter of the moving blade 140 according to the embodiment is likely to be larger than the diameter of the moving blade of a gas transfer device that does not have a hollow space. Therefore, the moving blade 140 according to the embodiment may be exposed to strong centrifugal stress. Furthermore, the temperature of each part of the gas transfer device 100 may rise during operation of the gas transfer device 100. Therefore, it is preferable that the moving blade 140 is as light as possible, can withstand strong centrifugal stress, and has high creep resistance. Therefore, the moving blade 140 according to the embodiment may be formed from an aluminum alloy containing silver. Moving blades formed from aluminum alloys are widely known, but it has been found that the strength of the moving blade 140 can be further improved by using an aluminum alloy containing silver. The silver content may be 0.01% to 5% (mass percent) under conditions of normal temperature and normal pressure. However, the silver content may be a percentage other than the above-mentioned percentage. More preferably, the rotor blade 140 may be formed by forging such an aluminum alloy. However, the rotor blade 140 may be formed from other materials and by other forming methods.

In the example of FIG. 1, the stator vane 150 is indirectly attached to the outer casing 120 via the heat transfer spacer 125. However, the stator vane 150 may be directly attached to the outer casing 120. The stator vane 150 may be configured to be separable from the heat transfer spacer 125 and/or the outer casing 120. The material of the stator vane 150 may be the same as or different from the material of the rotor blade 140. The stator vane 150 may be formed integrally with the heat transfer spacer 125. More specifically, at least one of the stator vane bases 151 described later may be formed integrally with the heat transfer spacer 125. When the stator vane 150 and the heat transfer spacer 125 are separate and independent parts, a gap may be generated between the stator vane 150 and the heat transfer spacer 125. As described later, the gas transfer device 100 according to the embodiment can be used not only under molecular flow conditions but also under intermediate flow conditions or viscous flow conditions. If a gap exists between the stator blade 150 and the heat transfer spacer 125 under intermediate flow conditions or viscous flow conditions, it is considered that gas is likely to leak from the processing chamber 11 through such a gap. Conversely to gas leakage, there is also a possibility that unintended gas may enter the processing chamber 11 through such a gap. Furthermore, the gas transfer device 100 according to the embodiment has a hollow space 112. Therefore, the diameter of the stator blade 150 according to the embodiment is likely to be larger than the diameter of the stator blade of a gas transfer device that does not have a hollow space. Therefore, in the gas transfer device 100 according to the embodiment, the size of the gap between the stator blade 150 and the heat transfer spacer 125 (which may be expressed as "gap length", "gap area", or "gap volume") is likely to be large. It is considered that the larger the gap, the greater the amount of gas leaking from the processing chamber 11/the amount of gas flowing into the processing chamber 11. To minimize the occurrence of gaps between the stator blades 150 and the heat transfer spacer 125, the stator blades 150 (or at least a part of the stator blades 150) are integrally formed with the heat transfer spacer 125 (or at least a part of the heat transfer spacer 125), thereby reducing the leakage of gas from the processing chamber 11/the inflow of gas into the processing chamber 11.

While the gas transfer device 100 transfers gas, heat is generated inside the gas transfer device 100. The generated heat warms the stator blades 150. The heat of the stator blades 150 is transferred to the outer cylinder 120 (through the heat transfer spacer 125 if the heat transfer spacer 125 is provided). The heat transferred to the outer cylinder 120 is dissipated to the external space in the configuration of FIG. 1. However, unlike FIG. 1, some other parts may be provided outside the outer cylinder 120. For example, if the lower part of the processing chamber 11 is formed in a cylindrical shape and the gas transfer device 100 is attached to such a cylindrical part, the wall of the processing chamber 11 may exist around the outer cylinder 120. In order to efficiently conduct heat between each part, it is preferable to make adjacent parts contact each other.

On the other hand, when the stator blades 150, the heat transfer spacer 125 (if present), and the outer cylinder 120 receive heat, each part may expand due to the heat. Furthermore, since heat moves from the inside to the outside of the gas transfer device 100, the parts located inside the gas transfer device 100 tend to become hotter than the parts located outside. (However, depending on the configuration of the device and the specific heat or heat capacity of each part, the parts located outside may become hotter.) Therefore, when gas is transferred by the gas transfer device 100 with adjacent parts in contact with each other, a phenomenon similar to shrink fitting occurs. That is, when gas is transferred by the gas transfer device 100, adjacent parts may press against each other due to thermal expansion. When parts are pressed against each other due to thermal expansion, it becomes impossible to disassemble the parts, or at least it becomes difficult to disassemble the parts until the temperature of the parts drops. In addition, it is thought that deformation of the parts may occur due to the parts pressing against each other. Since the hollow space 112 is provided in the gas transfer device 100, the diameter of each part tends to become large. As the diameter of the parts increases, the amount of radial expansion due to heat also increases, so problems due to thermal expansion are expected to become more serious.

To address problems caused by a phenomenon similar to shrink fitting, the vanes 150, the heat transfer spacers 125 (if present), and the casing 120 may be dimensioned to satisfy at least one of the following conditions:
When the temperature of the stator vane 150 reaches or exceeds a first predetermined temperature (e.g., a temperature 20 degrees lower than the maximum allowable temperature of the gas transfer device 100), the stator vane 150 comes into contact with a component on its outer periphery (e.g., the heat transfer spacer 125 or the outer casing 150). In other words, when the temperature of the stator vane 150 is lower than the first predetermined temperature, the stator vane 150 does not come into contact with a component on its outer periphery (a gap is formed).
When the temperature of the heat transfer spacer reaches or exceeds a second predetermined temperature (e.g., a temperature 30 degrees lower than the maximum allowable temperature of the gas transfer device 100), the heat transfer spacer 125 comes into contact with a component located on its periphery (e.g., the outer cylinder 120). In other words, when the temperature of the heat transfer spacer 125 is lower than the second predetermined temperature, the heat transfer spacer 125 does not come into contact with a component located on its periphery.
When the temperature of the outer cylinder 120 reaches or exceeds a third predetermined temperature (e.g., a temperature 40 degrees lower than the maximum allowable temperature of the gas transfer device 100), the outer cylinder 120 comes into contact with the components on its outer periphery (e.g., the processing chamber 11). In other words, when the temperature of the outer cylinder 120 is lower than the third predetermined temperature, the outer cylinder 120 does not come into contact with the components on its outer periphery.

According to a configuration that satisfies at least one of the above conditions, when the temperature of the parts reaches or exceeds a predetermined temperature, the parts come into contact with each other, and heat is conducted between the parts. Therefore, when the temperature of the parts reaches or exceeds a predetermined temperature, it becomes possible to dissipate heat from the gas transfer device 100. On the other hand, at room temperature, gaps are formed between the parts. Therefore, the force with which one part presses down on another due to thermal expansion can be reduced. This makes it possible to solve problems caused by a phenomenon similar to shrink fitting.

The rotor blade 140 will be described in detail with reference to Figure 3. Figure 3A is a top view of the rotor blade 140 as viewed from the intake side. Figure 3B is a front view of the rotor blade 140. The rotor blade 140 of this embodiment includes a cylindrical, hollow rotor blade base 141. The rotor blade base 141 is provided with four rotor blade stages 142. Each of the rotor blade stages 142 is an assembly of individual rotor blades 143. Each of the individual rotor blades 143 is formed radially around the central axis of the rotor blade base 141. When the gas transfer device 100 is assembled, the central axis of the rotor blade base 141 approximately coincides with the central axis 113 of the cylindrical portion 111 of the inner cylinder 110. Therefore, it is said that the rotor blade base 141 is a cylindrical rotor blade base.
It is possible to read "the central axis of the rotor blades 113" as "the central axis 113." Furthermore, the number of rotor blade stages 142 and the number and angle of each rotor blade 143 are not limited to those shown in the figure.

The rotor blades 140 can rotate around the central axis 113. Each of the rotor blades 143 is inclined so that the front part is located on the intake side and the rear part is located on the exhaust side with respect to the rotation direction 300 of the rotor blades 140. With this configuration, each rotor blade 143 collides with gas molecules during rotation to add kinetic energy to the gas molecules, and transfers the gas molecules from the top of the paper in FIG. 1 to the bottom of the paper. In addition, it is generally known that in order to increase the intake efficiency of molecules on the intake side and prevent backflow of molecules on the exhaust side, the inclination angle of the rotor blade stage 142 located on the intake side is increased and the inclination angle of the rotor blade stage 142 located on the exhaust side is decreased. On the other hand, the gas transfer device 100 according to the embodiment needs to keep gas such as process gas in the processing chamber 10. Therefore, all the inclination angles of the rotor blade stages 142 may be approximately the same. Specifically, all of the individual moving blades 143 may be inclined between 10 degrees and 30 degrees (however, the inclination angle when each moving blade 143 is parallel to the left and right direction in FIG. 3B is 0 degrees). Of course, it is also possible to set the angle to be smaller than 10 degrees or smaller than 30 degrees. With this configuration, it is possible to maintain the necessary compression ratio, the necessary gas transfer performance, and to keep gas such as a process gas inside the processing chamber 10. The faster the rotation speed of the moving blades 140, the higher the transfer efficiency of gas molecules. Therefore, by increasing or decreasing the rotation speed of the moving blades 140, the piping conductance of the gas flow path 130 can be increased or decreased. As an example, it is possible to adopt a configuration in which the control device 20 controls the rotation speed of the moving blades 140.

Next, the stator vane 150 will be described in detail with reference to FIG. 4. FIG. 4A is a top view of the stator vane 150 (or at least a part of the stator vane 150) seen from the intake side. FIG. 4B is a front cross-sectional view of the stator vane 150 (or at least a part of the stator vane 150). The stator vane 150 has a cylindrical, hollow stator vane base 151. The stator vane base 151 is configured to be split into two at the position of a split line 154. When assembling the stator vane base 151, the two parts are attached so as to sandwich the rotor vane 140. However, the stator vane base 151 is not limited to having a split structure. In addition, the stator vane base 151 has one stator vane stage 152. As can be understood from the fact that multiple parts (four in FIG. 1) are assigned the same reference number "150" in FIG. 1, the stator vane 150 may be a stack of multiple stator vane bases 151. By stacking the stator vane bases 151, the stator vane 150 as a whole has a plurality of stator vane stages 152. When one stator vane base 151 has one stator vane stage 152, the number of stator vane bases 151 is preferably equal to the number of rotor blade stages 142. The stator vane stage 152 is an assembly of individual stator vanes 153. Each of the individual stator vanes 153 is formed radially around the central axis of the stator vane base 151 (which can be read as the central axis 113). However, the number of stator vane stages 152 provided on one stator vane base 151, the number of stator vane stages 152 as a whole of the stator vane 150, and the number and angle of each stator vane 153 are not limited to the numbers shown in the figure.

Each of the individual stator vanes 153 is inclined in the opposite direction to each of the rotor blades 143. That is, each of the individual stator vanes 153 is inclined so that the front part is located on the exhaust side and the rear part is located on the intake side with respect to the rotation direction 300 of the rotor blade 140. With this configuration, the stator vanes 150 prevent the movement of gas molecules from the bottom of the paper to the top of the paper in FIG. 1 (backflow of gas molecules). As with the rotor blade 140, it is known that the inclination angle of the stator vane stage 152 located on the intake side is large and the inclination angle of the stator vane stage 152 located on the exhaust side is small for the stator vanes 150. As with the rotor blade 140 (rotor blade stage 142), the inclination angles of all of the stator vane stages 152 may be approximately the same. Specifically, all of the individual stator vanes 153 may be inclined between 10 degrees and 30 degrees (however, the inclination angle when each stator vane 153 is parallel to the left and right direction of FIG. 4B is 0 degrees). Of course, it is also possible to set the angle to less than 10 degrees or less than 30 degrees.

According to the above configuration, the rotor blades 140 (individual rotor blades 143) and the stator blades 150 (individual stator blades 153) each act as a blade for transporting gas molecules in addition to reducing the conductance of the gas passage 130. Here, the following definition is provided in the JIS (Japanese Industrial Standards).
JIS Z 8126-2:1999 2.1.2.5 "Molecular pump": "A momentum transport vacuum pump in which momentum is imparted to gas molecules by a high-speed rotor surface, and the gas is transported in the direction of the pump exhaust port."
JIS Z 8126-2:1999 2.1.2.5.1 "Turbomolecular pump": "A molecular pump in which a rotor has grooves or blades and rotates between a corresponding similar stator. The peripheral speed of the rotor is approximately the same as the speed of motion of the gas molecules. It usually performs well under molecular flow conditions."

The gas transfer device 100 according to the embodiment transfers gas in the direction of the exhaust port by imparting momentum to gas molecules with the moving blades 140 (individual moving blades 143). Therefore, in light of the JIS definition, the gas transfer device 100 according to the embodiment is a molecular pump. Furthermore, the gas transfer device 100 according to the embodiment is configured such that the moving blades 140 (stage 142 of moving blades) rotate between the stationary blades 150 (stage 152 of stationary blades). Therefore, in light of the JIS definition, the gas transfer device 100 according to the embodiment is a turbomolecular pump. However, the gas transfer device according to the embodiment is provided to "reducing the piping conductance to uniformly maintain the gas supplied from the process gas supply mechanism 12 to the inside of the vacuum device 10 inside the processing chamber 11." It is considered that the inside of the processing chamber 11 to which the process gas is supplied can be under not only molecular flow conditions but also viscous flow conditions or intermediate flow conditions. Therefore, please note that the gas transfer device in this embodiment is different from a typical turbomolecular pump (which, according to the JIS, "usually demonstrates its performance under molecular flow conditions").

When multiple stator vane bases 151 are stacked, it is preferable that the stator vane bases 151 are connected to each other in the form of a spigot joint. For example, as shown in FIG. 4, a convex portion 155 may be provided on the inner circumferential side of the upper surface of the stator vane base 151. A concave portion 156 corresponding to the convex portion 155 may be provided on the inner circumferential side of the lower surface of the stator vane base 151. By combining the convex portion 155 with the concave portion 156, the multiple stator vane bases 151 can be positioned with high precision. In addition, by increasing the precision of the positioning of the stator vane base 151, it is possible to accurately manage the gap length between the rotor vane 140 and the stator vane 150. Note that the structure in FIG. 4 is merely an example. For example, unlike FIG. 4, a concave portion 156 may be provided on the upper surface of the stator vane base 151, and a convex portion 155 may be provided on the lower surface of the stator vane base 151. The convex portion 155 and the concave portion 156 may be provided on a portion other than the inner circumferential side of the stator vane base 151.

(Regarding bearings)
The gas transfer device 100 includes a bearing for rotatably supporting the rotor blades 140. The bearing may be a rolling bearing or a magnetic bearing. In the example of FIG. 1, a magnetic bearing 160 is provided between the inner cylinder 110 and the rotor blades 140. The magnetic bearing 160 in the example of FIG. 1 includes two sets of radial magnetic poles 161 and one set of axial magnetic poles 162. The magnetic bearing in FIG. 1 further includes a touchdown bearing 163.

The radial magnetic poles 161 are magnetic poles for supporting the radial load of the rotor blade 140. In the example of FIG. 1, the radial magnetic poles 161 are provided on the outer peripheral surface of the cylindrical portion 111 of the inner cylinder 110 and the inner peripheral surface of the rotor blade 140. The radial magnetic poles 161 may be provided with a radial displacement sensor (not shown) that measures the radial displacement between the inner cylinder 110 and the rotor blade 140. In this case, the control device 20 controls the radial magnetic poles 161 based on the measurement amount of the displacement sensor, thereby stabilizing the rotation of the rotor blade 140.

The axial magnetic pole 162 is a magnetic pole for supporting the axial load of the moving blade 140. In the example of FIG. 1, the axial magnetic pole 162 is provided on the stage mounting portion 114, which is a part of the inner cylinder 110. In addition to the axial magnetic pole 162, an axial magnetic pole target 164, which is a target of the axial magnetic pole 162, an axial sensor holder 165 for holding an axial displacement sensor (not shown), and an axial sensor target 166, which is a target of the axial displacement sensor, may be provided. Here, the axial displacement sensor is a sensor that measures the axial displacement between the inner cylinder 110 and the moving blade 140. In the example of FIG. 1, the axial magnetic pole target 164 and the axial sensor target 166 are fixed to the moving blade 140 and rotate together with the moving blade 140. In addition, as shown in FIG. 1, the axial magnetic pole 162, the axial magnetic pole target 164, the axial sensor holder 165, and the axial sensor target 166 are located in positions accessible from the top of the gas transfer device 100, making it easy to replace the axial magnetic pole 162.

The touchdown bearing 163 is a bearing that operates when the magnetic bearing 160 becomes uncontrollable. In the example of FIG. 1, the touchdown bearing 163 is provided between the stage mounting portion 114, which is part of the inner cylinder 110, and the rotor blade 140.

Conventionally, a two-point contact ball bearing capable of supporting a load in one direction, either the radial or axial direction, was used as the touchdown bearing 163. However, when the magnetic bearing 160 is stopped in an emergency, loads can occur in both the radial and axial directions. In the conventional technology, therefore, two two-point contact ball bearings were combined (double row) to support both radial and axial loads. On the other hand, in this embodiment, a four-point contact single row ball bearing is used as the touchdown bearing 163. A four-point contact ball bearing can support both radial and axial loads with one (single row) bearing. By making the touchdown bearing a single row, it is possible to achieve a reduction in the size and number of parts. In addition to the four-point contact single row ball bearing, it is also possible to adopt bearings such as a normal single row ball bearing, an angular ball bearing, and a cylindrical roller bearing.

Furthermore, the touchdown bearing 163 may be glass coated. The application of a glass coating improves the hardness and slipperiness of the touchdown bearing 163. Therefore, the glass coating can reduce damage to the touchdown bearing 163, for example, when the magnetic bearing 160 is stopped in an emergency. Similarly, the glass coating can reduce damage to other parts that come into contact with the touchdown bearing 163. When using a ball bearing as the touchdown bearing 163, it is preferable to apply a glass coating to at least one of the balls inside the bearing and the points where the balls come into contact.

In order to reduce damage to the touchdown bearing 163 and other parts that come into contact with the touchdown bearing 163, other lubricants may be used in addition to the glass coating. As the lubricant, for example, a solid lubricant containing molybdenum disulfide or tungsten disulfide may be used. At least a part of the touchdown bearing 163 may be made of a high-strength material. An example of a high-strength material is nickel-chromium-molybdenum steel. By making the touchdown bearing 163 from a high-strength material, the number of times the touchdown bearing can be used can be increased. In particular, by making the part of the touchdown bearing 163 that rotates together with the moving blade 140 from a high-strength material, the touchdown bearing 163 can withstand strong rotational stress. Since the gas transfer device 100 according to the embodiment has the hollow space 112, the diameter of the moving blade 140 is likely to be large. Therefore, the rotational stress generated in the touchdown bearing 163 (more precisely, the part of the touchdown bearing 163 that rotates together with the moving blade 140) is also likely to be large. It is therefore important to configure the touchdown bearing 163 so that it can withstand rotational stresses.

If the magnetic bearing 160 becomes uncontrollable and the touchdown bearing 163 starts to operate, there is a possibility that the rotation axis of the moving blade 140 will vibrate around the touchdown bearing 163. Therefore, the gap distance between the radial magnetic pole 161 provided on the outer circumferential surface of the cylindrical portion 111 of the inner cylinder 110 and the radial magnetic pole 161 provided on the inner circumferential surface of the moving blade 140 is configured so that the radial magnetic poles do not come into contact with each other even if the rotation axis of the moving blade 140 vibrates. Here, it is considered that the radial magnetic pole 161 far from the touchdown bearing 163 moves in the direction perpendicular to the rotation axis due to the vibration of the rotation axis larger than the radial magnetic pole 161 close to the touchdown bearing 163. Therefore, by increasing the gap distance of the radial magnetic poles provided far from the touchdown bearing 163, it is possible to effectively prevent the radial magnetic poles from contacting each other.

In addition, among the components of the magnetic bearing 160, the components that rotate together with the moving blade 140 may rotate at high speed. Conventionally, it has been known to provide a ring-shaped spacer member between the components of the magnetic bearing 160 that rotate together with the moving blade 140 and the moving blade 140 in order to prevent the components from coming loose during rotation. The spacer member can firmly hold the components of the magnetic bearing. On the other hand, there is a problem that the number and weight of the components of the gas transfer device 100 as a whole are increased by providing a spacer member. In addition, when the diameter of the moving blade 140 is large, as in the gas transfer device 100 according to the embodiment, the amount of thermal expansion of each component is large. If a spacer member is used when the amount of thermal expansion is large, the possibility of each component interfering with each other due to the expansion increases. Therefore, the moving blade 140 of the gas transfer device 100 according to the embodiment may be connected to the components of the magnetic bearing 160 by shrink fitting without using a spacer member. More specifically, a groove may be dug in the inner peripheral portion of the moving blade 140, and the components of the magnetic bearing may be shrink fitted into the groove. The shrink-fit temperature is preferably higher than the maximum allowable temperature of the gas transfer device 100 (e.g., 120°C). By shrink-fitting at such a temperature, the possibility of parts falling off can be reduced even when the gas transfer device 100 is at its highest temperature. Note that the magnetic bearing 160 parts and the rotor blade 140 may be joined by cold fitting instead of shrink fitting.

(Regarding motors)
The gas transfer device 100 further includes a motor for rotating the rotor blades 140. In the example of Fig. 1, the center of rotation of the rotor blades 140 is the central shaft 113. In the example of Fig. 1, one radial gap type motor 170 including a rotor 171 and a stator 172 is used as the motor. The rotor 171 is provided on the rotor blades 140. The stator 172 is provided in a position facing the rotor 171 in the cylindrical portion 111 of the inner cylinder 110.

The above-mentioned arrangement and number of bearings and motors are merely examples. Any conventionally known configurations of bearings and motors may be used as long as they do not contradict the description in this specification.

(Regarding connectors and wiring)
In order to operate the components of the gas transfer device 100 (such as the magnetic bearing 160 and the radial gap type motor 170), it is necessary to supply power to those components. That is, the gas transfer device 100 may require a connector for electrically connecting the inside and outside of the gas transfer device 100. Here, components such as a cable 15 connected to an AC power source 14 and the like are present in the hollow space 112. Therefore, in order to avoid interference between the components present inside the hollow space 112, such as the cable 15, and the connector, it is preferable to provide the connector in a location other than the cylindrical portion 111 of the inner cylinder 110.

Therefore, in this embodiment, the connector 118 is provided at the bottom of the exhaust side of the outer tube 120, which is the bottom of the exhaust side of the gas transfer device 100. It is also possible to provide the connector 118 at the bottom of the exhaust side of the inner tube 110. If the inner tube 110 and the outer tube 120 are connected by a bottom plate, the connector 118 may be provided at the bottom plate. With the above configuration, it is possible to avoid interference between the parts present in the cylindrical part 111 of the inner tube 110 and the connector 118. It is also possible to provide multiple connectors 118 in order to reduce the number of pins per connector 118. Although there are exceptions, a connector with a small number of pins is generally smaller than a connector with a large number of pins. Therefore, by using multiple connectors 118, it is possible to reduce the size of the connector 118. The number of connectors 118 may be appropriately determined depending on the number of parts, the number of pins required (the number of conductive paths required), the dimensions of the part where the connector 118 is provided, etc.

Furthermore, in this embodiment, a groove 203 for laying wiring connected to the connector 118 is formed on the outer circumferential surface of the cylindrical portion 111 of the inner cylinder 110 (see FIG. 2). By laying wiring in this groove 203 to connect between the connector 118 and various components (such as a motor), it is possible to prevent the wiring from becoming entangled in the rotor blades 140, etc. The shape of the groove 203 may be any shape depending on the arrangement and number of components to which the wiring is connected.

(About the airflow adjustment baffle plate)
1, if exhaust port 122 of gas transfer device 100 is present only on the left side of the page, the flow path length of the left side of gas flow path 130 will be shorter than the flow path length of the right side of the page. As a result, the piping conductance of the left side of gas flow path 130 may be greater than the piping conductance of the right side of the page. Therefore, when gas transfer device 100 is attached to vacuum device 10 and driven, the degree of vacuum may be high in the left side of vacuum device 10 and low in the right side of the page.

In addition, in this embodiment, the inside of the vacuum device 10 is evacuated by collision of gas molecules inside the vacuum device 10 with each of the moving blades 143 of the moving blades 140. Each of the moving blades 143 rotates in a rotation direction 300 around the central axis 113 (see FIG. 3A). The rotation of each of the moving blades 143 can generate a swirling flow inside the vacuum device 10. It is difficult to control the swirling flow, and the swirling flow can cause the degree of vacuum to become uneven, so it is preferable to avoid the generation of the swirling flow as much as possible.

The gas transfer device in FIG. 1 is provided with an airflow adjustment baffle plate 180 having an air vent 181 at a position adjacent to the intake side of the rotor blade 140. The airflow adjustment baffle plate 180 is a baffle plate independent of the rotor blade 140 and the stator blade 150, and is a plate for adjusting the airflow inside the vacuum device 10. The airflow adjustment baffle plate 180 may be one whose installation position, installation angle, and/or size of the air vent, etc., can be adjusted.

The vents 181 of the airflow adjustment baffle plate 180 are provided to compensate for the change in piping conductance of the gas flow path 130 due to the position. Furthermore, the vents 181 are provided to prevent the occurrence of swirling flow. As a specific example, the airflow adjustment baffle plate 180 can be made ring-shaped and multiple vents 181 can be provided. In this case, by appropriately selecting the shape, size and/or installation position of each vent, it is possible to compensate for the difference in piping conductance of the gas flow path 130. For example, in FIG. 1, the vent 181 on the right side of the page is formed larger than the vent 181 on the left side of the page. In addition, airflow adjustment baffle plate 180 and vents 181 of any shape can be adopted depending on the desired performance.

It is also possible to suppress the generation of swirling flow by using the stator vane 150 instead of the airflow adjustment baffle plate 180. In the configuration of FIG. 1, the stage of the rotor blade 142 and the stage of the stator vane 152 that is located closest to the intake side is the stage of the rotor blade 142. Instead of the configuration of FIG. 1, the gas transfer device 100 may be configured as shown in FIG. 12 so that the stage of the stator vane 152 is located closest to the intake side. According to the configuration of FIG. 12, the stage of the stator vane 152 is located closer to the intake side than the stage of the rotor blade 142 that is closest to the intake side, so that the generation of swirling flow by the rotor blade 140 can be suppressed. Note that the configuration of FIG. 12 is obtained by deleting the stage of the rotor blade 142 located closest to the intake side from the configuration of FIG. 1. However, the stage of the stator vane 152 may be located closest to the intake side by other methods, such as adding the stage of the stator vane 152 to the configuration of FIG. 1.

(Gas purge port)
Furthermore, the gas transfer device 100 according to this embodiment includes a gas purge port 191 for supplying gas to an exhaust side space 190 defined by the inner cylinder 110 and the rotor blades 140. More specifically, the exhaust side space 190 may be a space defined by the outer circumferential surface of the inner cylinder 110 and the inner circumferential surface of the rotor blades (more specifically, the rotor blade base 141).

In the example of FIG. 1, the gas purge port 191 is provided in the stage mounting portion 114, which is a part of the inner cylinder 110. However, the location where the gas purge port 191 is provided is an example. As long as gas can be supplied to the exhaust side space 190, the gas purge port 191 may be provided in any location of the inner cylinder 110 or in another component (e.g., the outer cylinder 120). In addition, a purge gas supply mechanism 192 that supplies purge gas via the gas purge port 191 is connected to the gas purge port 191.

For example, if the vacuum device 10 is a dry etching device, sulfur hexafluoride or the like that is supplied to the dry etching device and converted into plasma may damage the components of the gas transfer device 100 (particularly the motor or bearings, etc.). Therefore, the gas transfer device 100 of this embodiment protects the components of the gas transfer device 100 by supplying a non-reactive gas from the purge gas supply mechanism 192 to the exhaust side space 190 via the gas purge port 191. It is preferable to use dry air, argon, nitrogen, or the like as the purge gas.

Gas can be constantly supplied from the purge gas supply mechanism 192 while the gas transfer device 100 is in operation. However, this method can result in a large amount of gas consumption. Therefore, when it is necessary to protect the components of the gas transfer device 100, that is, when at least one of the following cases is true: (1) a specific type of gas (particularly a gas that may damage the components of the gas transfer device 100 (e.g., a process gas supplied by the process gas supply mechanism 12)) is supplied to the processing chamber 11, and (2) the degree of vacuum inside the processing chamber 11 is equal to or greater than a specific value, gas may be supplied from the purge gas supply mechanism 192 through the gas purge port 191. By supplying gas in at least one of the above cases (1) and (2), it may be possible to reduce the amount of gas consumed.

(About the spiral structure)
Since the rotating body such as the moving blade 140 in the gas transfer device 100 rotates at high speed, it is difficult to provide a gasket such as an O-ring on the rotating body. Therefore, a small gap is provided between the rotating body and the stationary body in the gas transfer device 100. Since the size of the gap is small, no large gas outflow occurs from this gap. However, as long as the gap exists, even if it is small, there is a possibility that a small amount of gas outflow occurs through this gap as a gas outflow flow path. In particular, when gas is supplied from the gas purge port 191, there is a possibility that the supplied gas will flow out into the inside of the vacuum device 10. Therefore, in this embodiment, a spiral structure 501 (thread groove structure) is formed in the gas outflow flow path 500 between the exhaust side space 190 defined by the inner cylinder 110 and the moving blade 140 and the inside of the vacuum device 10.

5 is an enlarged cross-sectional view of the periphery of the axial magnetic pole 162 in the gas transfer device 100 shown in FIG. 5, a gas purge port 191 is provided in the stage mounting portion 114 so as to supply gas between the axial magnetic pole 162 and the touchdown bearing 163. A part of the gas supplied from the gas purge port 191 flows to the exhaust side through the touchdown bearing 163 to protect the components of the gas transfer device 100. On the other hand, the gas flowing from the gas purge port 191 to the intake side can flow into the inside of the processing chamber 11 through the gaps between the axial magnetic pole 162, the axial magnetic pole target 164, the axial sensor holder 165, and the axial sensor target 166. That is, this gap becomes a gas outflow passage 500.

In FIG. 5, a spiral structure 501 is formed in the axial sensor holder 165 of the gas outflow passage 500. FIG. 6 shows the axial sensor holder 165 on which the spiral structure 501 is formed, with FIG. 6A being a front view and FIG. 6B being a bottom view seen from the exhaust side. In this embodiment, the spiral structure 501 includes both a spiral structure 601 formed on the side surface and a spiral structure 602 formed on the bottom surface. However, the spiral structure may be formed on only one of the side surface or the bottom surface.

In the gas transfer device 100 of this embodiment, the gas flowing to the intake side passes through the spiral structure 501 of the gas outflow passage 500. Therefore, the passage length when the spiral structure 501 is provided is longer than the passage length when the spiral structure 501 is not provided. As a result, the piping conductance of the gas outflow passage 500 is reduced, and the amount of gas flowing out from the gas outflow passage 500 can be reduced.

In this embodiment, the rotation direction 300 of the moving blade 140 is clockwise as viewed from the intake side (see FIG. 3A). Furthermore, the helical structure 601 formed on the side is formed like a right-handed screw (see FIG. 6A). When gas molecules present inside the helical structure 601 formed on the side collide with the rotating moving blade 140 (or other parts rotating together with the moving blade 140), the gas molecules receive a force in the rotation direction 300 and move. By moving clockwise as viewed from the intake side inside the right-handed helical structure 601 formed on the side, the gas molecules gradually move to the exhaust side. Therefore, by adopting a right-handed screw structure, it is possible to reduce the possibility that gas molecules introduced from the gas purge port 191 will flow into the processing chamber 11 through the gas outflow passage 500.

If only the spiral structure 601 formed on the side surface is changed to a left-handed thread without changing the other structures, the gas molecules inside the spiral structure 601 formed on the side surface gradually move toward the intake side. Therefore, by adopting a left-handed thread structure, it is possible to reduce the possibility that gas molecules inside the processing chamber 11 will flow out to the exhaust side space 190 via the gas outflow passage 500. Note that when the rotor blade 140 is rotating in the opposite direction to the rotation direction 300, the characteristics of the right-handed thread structure and the left-handed thread structure are interchanged.

Like the spiral structure 601 formed on the side, the spiral structure 602 formed on the bottom surface also has different characteristics depending on the direction in which it is formed. The characteristics of the spiral structure 601 formed on the side and the spiral structure 602 formed on the bottom surface, i.e., the characteristics of the spiral structure 501 as a whole, may be appropriately selected as needed.

5 and 6, the spiral structure 501 is provided only on the axial sensor holder 165. However, the spiral structure 501 may be provided anywhere on the gas outflow passage 500. Also, in the example of FIG. 5 and FIG. 6, the spiral structure 501 is provided only on one side of the gas outflow passage 500. However, the spiral structure 501 can be provided on both sides of the gas outflow passage 500 so that the spiral structures 501 face each other. The groove width, number of grooves, and other specific structures of the spiral structure 501 may be determined according to the desired performance.

(Regarding the separation structure of the stage mounting part)
For example, if the vacuum device 10 is a dry etching device, the moving blades 140 and the stationary blades 150 may be damaged by contact with plasma-converted gas. Furthermore, if emergency stops of the gas transfer device 100 are repeated, damage accumulates in the touch-down bearing 163. Therefore, the maintainability of the gas transfer device 100 becomes important in order to maintain the moving blades 140, the stationary blades 150, the touch-down bearing 163, and other parts.

The stage mounting part 114 of the gas transfer device 100 according to this embodiment is provided so as to be separable from the inner cylinder 110 (see FIG. 2). Furthermore, in the gas transfer device 100 according to this embodiment, the moving blade 140 is connected to the stage mounting part 114 via a magnetic bearing. Therefore, by pulling out the stage mounting part 114 separated from the inner cylinder 110 in the direction of the intake side, it is possible to remove the moving blade 140 from the gas transfer device 100. In addition, it is also possible to remove the stationary blade 150 from the gas transfer device 100 at the same time as removing the moving blade 140. FIG. 7 shows the gas transfer device 100 in a state in which the stage mounting part 114 has been pulled out. Note that the stator 172, touchdown bearing 163, axial magnetic pole 162, etc. may also be configured to be removed from the gas transfer device at the same time as removing the moving blade 140. With this configuration, it is possible to easily access each of the removed parts, so that the maintainability of the gas transfer device 100 can be significantly improved.

(Effects of the gas transfer device)
In the gas transfer device 100 having the above configuration, the conductance of the gas flow passage 130 is reduced by the moving blades 140 and the stationary blades 150. Therefore, the gas supplied from the process gas supply mechanism 12 to the inside of the vacuum device 10 can be uniformly maintained inside the processing chamber 11. Furthermore, since the gas transfer device 100 also functions as a turbo molecular pump 100, it is also possible to exhaust gas from inside the processing chamber 11. Here, the gas flow passage 130 of the gas transfer device 100 forms a ring-shaped intake port centered on the stage mounting portion 114. Therefore, it is possible to uniform the degree of vacuum inside the vacuum device 10 (particularly near the substrate 116) more easily than in the conventional device.

(Regarding control of gas transfer device)
Not only can the degree of vacuum inside the vacuum device 10 be made uniform, but the degree of vacuum inside the vacuum device 10 can also be adjusted by the gas transfer device 100 of FIG. 1. The degree of vacuum is adjusted by controlling at least one of the rotation speed of the moving blades 140 and the amount of gas supplied by the process gas supply mechanism 12 while or after the process gas supply mechanism 12 supplies gas to the process chamber 11 so that the degree of vacuum in the process chamber 11 becomes a desired degree of vacuum. The control may be performed manually by a user or by the control device 20. The above-mentioned "desired degree of vacuum" can also be set lower than the degree of vacuum at the most exhaust side of the gas flow path 130. In this case, the compression ratio of the gas transfer device 100 is less than 1.

Second Embodiment
FIG. 8 is a schematic diagram showing a cross section of the gas transfer device 100 according to the second embodiment. The gas transfer device 100 according to the second embodiment includes a rolling bearing 860 instead of the magnetic bearing 160 in FIG. 1, and an axial gap type motor 870 instead of the radial gap type motor 170. The axial gap type motor 870 in the example of FIG. 8 includes a rotor 871 and a stator 872 that are spaced apart from each other in the direction of the rotation axis, and the rotor 871 includes a magnet 873 and a rotor yoke 874. In addition, in the gas transfer device 100 of this embodiment, the stage attachment part 114 is integrally formed with the inner cylinder 110. Furthermore, the exhaust port 122 is provided on the side of the outer cylinder 120, not on the bottom surface thereof. Furthermore, the inner cylinder 110 and the outer cylinder 120 are connected via a bottom plate 800. Furthermore, in this embodiment, an airflow adjustment baffle plate 18 is provided.
In this respect, the second embodiment does not include the control device 20, the connector 118, the first bolt 124, the purge gas supply mechanism 192, and the like.

(Regarding rolling bearings)
The rolling bearing 860 is subject to greater wear than the magnetic bearing 160, but is less expensive than the magnetic bearing 160. In the example of Fig. 8, a double-row ball bearing is used as the rolling bearing 860. A glass coating may be applied to the portion of the rolling bearing 860 where wear may occur.

(Axial gap motor)
As described in the first embodiment, when the radial gap type motor 170 is used, the radial gap type motor 170 is provided between the inner cylinder 110 and the moving blade 140 (exhaust side space 190) (see FIG. 1). Since the gap between the inner cylinder 110 and the moving blade 140 is not so large, when a large radial gap type motor 170 is used, the motor may interfere with other components. If a large radial gap type motor 170 is to be used, the shape of the inner cylinder 110 and/or the moving blade 140 must be changed to secure a space for installing the radial gap type motor 170. However, changing the shape of each component may lead to an increase in the size of the entire gas transfer device 100 or a decrease in the performance of the gas transfer device 100. On the other hand, when a small radial gap type motor 170 is used, sufficient motor output may not be obtained.

Therefore, the gas transfer device 100 according to this embodiment employs an axial gap motor 870. Unlike a general motor (radial gap motor), the axial gap motor 870 has a rotor 871 and a stator 872 spaced apart in the direction of the rotation axis. In the example of FIG. 8, the magnet 873 of the rotor 871 is provided at the exhaust side end of the moving blade 140 via a rotor yoke 874. The stator 872 is provided at a position facing the rotor 871 of the gas flow path 130. By arranging the rotor 871 and the stator 872 in this manner, interference with other parts in the radial direction is less likely to occur. Therefore, it is possible to use a motor with a sufficiently high output without increasing the size of the entire gas transfer device 100 and reducing the performance of the gas transfer device 100.

The axial gap motor 870 of this embodiment may also be advantageous in terms of leakage magnetic field. For example, if the vacuum apparatus 10 is a plasma etching apparatus, leakage of a magnetic field from the motor to the vicinity of the substrate 116 may adversely affect the etching process. The rotor 871 and stator 872 of the axial gap motor 870 of this embodiment are provided on the exhaust side, and are provided at a position farther from the stage mounting portion 114 than the radial gap motor 170 of the first embodiment. Therefore, the axial gap motor 870 of this embodiment may be able to reduce the amount of leakage magnetic field more than the radial gap motor 170.

In this embodiment, since a rolling bearing 860 is used instead of the magnetic bearing 160, the components of the magnetic bearing 160 (radial magnetic pole 161, axial magnetic pole 162, touchdown bearing 163, axial magnetic pole target 164, axial sensor holder 165, and axial sensor target 166) are not provided. Therefore, in this embodiment, the gap between the moving blade 140 and the inner cylinder 110 (stage mounting part 114 which is a part of the moving blade 140) becomes the gas outflow flow path 500. The spiral structure 501 is formed in the moving blade 140 and/or the inner cylinder 110 (stage mounting part 114 which is a part of the inner cylinder 110).

Third Embodiment
In the third embodiment, a touchdown bearing 163 is provided in a different position from that in the first embodiment.
A gas transfer device 100 including the above will be described with reference to Fig. 9. However, in Fig. 9, elements (such as the outer cylinder 120) that are not necessary for describing the installation location of the touchdown bearing 163 may be omitted from illustration.

As shown in FIG. 9, in this embodiment, the touchdown bearing 163 is provided near the exhaust side end of the rotor blade 140. In addition, due to the change in the installation location of the touchdown bearing 163, the axial magnetic pole 162 and the axial magnetic pole target 164 are also provided near the exhaust side end of the rotor blade 140.

Furthermore, in this embodiment, a sealing member 900 is provided at the intake side end of the rotor blade 140 to define the boundary between the exhaust side space 190 and the processing chamber 11. In the example of FIG. 9, the sealing member 900 is illustrated as a separate, independent part from the rotor blade 140. However, the sealing member 900 may be formed integrally with the rotor blade 140. In addition, a spiral structure 501 is provided on the portion of the inner cylinder 110 that faces the sealing member 900. Additionally or alternatively, a spiral structure 501 can also be provided on the portion of the sealing member 900 that faces the inner cylinder 110.

By providing the touchdown bearing 163 near the exhaust end of the rotor blade 140, the structure near the intake end of the rotor blade 140 can be simplified. As the structure is simplified, interference between parts near the intake end of the rotor blade 140 is less likely to occur. In addition, as the structure is simplified, there is an effect that the size of the gas transfer device 100, in particular the height of the gas transfer device 100, can be reduced.

Furthermore, the touchdown bearing 163 in this embodiment is provided on the exhaust side of the touchdown bearing 163 in the first embodiment (see FIG. 1, etc.). Therefore, the distance between the touchdown bearing 163 and the processing chamber 11 in this embodiment is longer than the distance between the touchdown bearing 163 and the processing chamber 11 in the first embodiment. In this embodiment, the process gas flowing out from the processing chamber 11 follows a relatively long path to reach the touchdown bearing 163. Since the concentration of the process gas decreases due to the diffusion of gas molecules while following the long path, it is considered that the reaction amount between the process gas and the touchdown bearing 163 in this embodiment decreases. Therefore, it is considered that the life of the touchdown bearing 163 can be extended in this embodiment.

Fourth Embodiment
In the fourth embodiment, a gas transfer device 100 including a bottom plate 1000 and capable of removing an inner cylinder 110 together with the bottom plate 1000 toward the inside of a processing chamber 11 will be described with reference to Figures 10 and 11. However, in Figure 11, illustration of elements (such as the processing chamber 11) that are not necessary for the description of removal of parts of the gas transfer device 100 may be omitted.

The gas transfer device 100 according to this embodiment includes a bottom plate 1000 in addition to the gas transfer device 100 shown in FIG. 1. The bottom plate 1000 is removably fixed to the bottom of the outer cylinder 120 in the direction toward the inside of the processing chamber 11 (the intake side). Any means such as bolts (not shown) can be used to fix the bottom plate 1000 and the outer cylinder 120. Furthermore, the bottom plate 1000 supports the inner cylinder 110 with a first bolt 124. In the example of FIG. 10, the exhaust port 122 and the connector 118 are provided on the bottom plate 1000. However, the exhaust port 122 and the connector 118 may be provided on the inner cylinder 110 or the outer cylinder 120 as long as they do not adversely affect the removal of the inner cylinder 110 described in FIG. 11.

11 is a diagram showing the gas transfer device 100 when the inner cylinder 110 is removed together with the bottom plate 1000 toward the inside of the processing chamber 11. In this embodiment, by removing the bottom plate 1000 from the outer cylinder 120 toward the inside of the processing chamber 11 (the intake side), it is possible to remove the inner cylinder 110 and the parts associated with the inner cylinder 110 together with the bottom plate 1000. Furthermore, the gas transfer device 100 and/or the vacuum device 10 according to this embodiment are configured so that interference between the gas transfer device 100 and the vacuum device 10 does not occur when the inner cylinder 110 is removed together with the bottom plate 1000.

The configuration of this embodiment has the advantage that the inner tube 110 and parts associated with the inner tube 110 can be easily removed, improving maintainability.

Although several embodiments of the present invention have been described above, the above-mentioned embodiments of the invention are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from its spirit, and the present invention naturally includes equivalents. Furthermore, any combination or omission of each component described in the claims and specification is possible within the scope of solving at least part of the above-mentioned problems or achieving at least part of the effects.

As one embodiment, the present application discloses a gas transfer device for transferring gas, comprising an inner cylinder having at least a cylindrical portion on at least a portion thereof and including a stage mounting portion provided on the intake side of the inner cylinder, an outer cylinder having at least a cylindrical portion on at least a portion thereof and arranged coaxially with the central axis of the inner cylinder, a rotor blade provided on a gas flow path defined by the inner cylinder and the outer cylinder, the rotor blade configured to be rotatable around the central axis, a stationary blade provided on the gas flow path, and a motor for rotating the rotor blade, the inner cylinder and the outer cylinder being formed hollow, and the gas transfer device further comprising a gas purge port for supplying gas to a space defined by the inner cylinder and the rotor blade.

One example of the effect of this gas transfer device is that it is possible to maintain the gas supplied to the inside of the vacuum device uniformly inside the processing chamber.

Furthermore, as one embodiment, the present application discloses a gas transfer device in which a gas purge port is provided in the inner cylinder or the outer cylinder. The contents of this disclosure reveal the details of the gas transfer device.

Furthermore, as one embodiment, the present application discloses a gas transfer device that includes a magnetic bearing disposed between the inner cylinder and the rotor blades to rotatably support the rotor blades, the magnetic bearing including a touchdown bearing, and the touchdown bearing being a four-point contact single row ball bearing.

This gas transfer device has the advantage of being able to reduce the size and number of parts by using a single row of touchdown bearings.

Furthermore, the present application discloses, as one embodiment, a gas transfer device in which a touchdown bearing is glass coated.

As an example, this gas transfer device has the effect of reducing damage sustained by the touchdown bearing and other parts that come into contact with the touchdown bearing through the glass coating.

Furthermore, as one embodiment, the present application discloses a gas transfer device that is provided at the bottom of the exhaust side of the gas transfer device and includes a connector for electrically connecting the inside and outside of the gas transfer device.

One example of the effect of this gas transfer device is that it is possible to avoid interference between the connector and parts present in the cylindrical portion of the inner tube.

Furthermore, as one embodiment, the present application discloses a gas transfer device in which a groove for laying wiring connected to a connector is formed on the outer circumferential surface of the cylindrical portion of the inner tube.

As an example, this gas transfer device has the effect of preventing the wiring from becoming entangled in the rotor blades 140, etc., by laying the wiring in the grooves.

Furthermore, as one embodiment, the present application discloses a gas transfer device in which a spiral structure is formed in the gas outflow passage.

As an example, this gas transfer device has the effect of reducing the amount of gas flowing out from the gas outflow passage.

Furthermore, as one embodiment, the present application discloses a gas transfer device in which the stage mounting portion is provided so as to be separable from the inner cylinder.Furthermore, as one embodiment, the present application discloses a gas transfer device configured so that the moving blades and stationary blades can be removed from the gas transfer device by separating the stage mounting portion from the inner cylinder.

One example of the effect of these gas transfer devices is that they can improve maintainability.

Furthermore, as one embodiment, the present application discloses a gas transfer device in which the motor is an axial gap type motor including a rotor and a stator, the rotor is provided on the exhaust side of the rotor blades, and the stator is provided in a position facing the rotor on the gas flow path.

This gas transfer device has the effect of making it possible to use a motor with sufficiently high output without increasing the size of the gas transfer device or reducing its performance.

Furthermore, as one embodiment, the present application discloses a gas transfer device that includes a rolling bearing disposed between the inner cylinder and the rotor blades, which rotatably supports the rotor blades.

This disclosure provides detailed configuration information when using an axial gap motor.

Furthermore, as one embodiment, the present application discloses a method of using a gas transfer device connected to a vacuum chamber, the method including the step of supplying gas to a space defined by the inner cylinder and the rotor blades through a gas purge port when at least one of (1) a predetermined type of gas is being supplied to the vacuum chamber and (2) the degree of vacuum inside the vacuum chamber is equal to or greater than a predetermined value.

One example of the effect of this method is that it may be possible to reduce gas consumption.

10... Vacuum device 11... Processing chamber (vacuum chamber)
12: Process gas supply mechanism 13: Shower head electrode 14: AC power supply 15: Cable 20: Control device 100: Gas transfer device 110: Inner cylinder 111: Cylindrical part of inner cylinder 112: Hollow space 113: Central axis 114: Stage mounting part 115: Stage 116: Substrate 117: First female threaded hole 118: Connector 120: Outer cylinder 121: Cylindrical part of outer cylinder 122: Exhaust port 123: First through hole 124: First bolt 125: Heat transfer spacer 130: Gas flow path 140: Rotating blade 141: Rotating blade base 142: Rotating blade stage 143: Individual rotating blade 150: Stator blade 151: Stator blade base 152: Stator blade stage 153: Individual stator blade 154: Parting line 155: Convex part Reference Signs List 156: Recess 160: Magnetic bearing 161: Radial magnetic pole 162: Axial magnetic pole 163: Touchdown bearing 164: Axial magnetic pole target 165: Axial sensor holder 166: Axial sensor target 170: Radial gap type motor 171: Rotor 172: Stator 180: Airflow adjustment baffle plate 181: Vent 190: Exhaust side space 191: Gas purge port 192: Purge gas supply mechanism 200: Second through hole 201: Second female threaded hole 202: Second bolt 203: Groove 300: Rotation direction of rotor blade 500: Gas outflow flow path 501, 601, 602: Spiral structure 800: Bottom plate 860: Rolling bearing 870: Axial gap type motor 871: Rotor 872: stator 873: magnet 874: rotor yoke 900: sealing member 1000: bottom plate

Claims (9)

A gas transfer device for transferring a gas, comprising:
an inner cylinder having at least a cylindrical portion at a portion thereof, the inner cylinder including a stage mounting portion provided on an intake side of the inner cylinder;
An outer cylinder having at least a cylindrical portion and arranged coaxially with a central axis of the inner cylinder;
a rotor blade provided on a gas flow path defined by the inner cylinder and the outer cylinder, the rotor blade being configured to be rotatable about the central axis;
A stator blade provided on the gas flow path;
A motor for rotating the rotor blades;
Equipped with
The inner cylinder and the outer cylinder are formed hollow,
the gas transfer device further includes a gas purge port for supplying a gas to an exhaust side space defined by an outer circumferential surface of the inner cylinder and an inner circumferential surface of the rotor blade;
The gas transfer device further includes a magnetic bearing or a rolling bearing provided between the inner cylinder and the rotor blades to rotatably support the rotor blades,
the magnetic bearing includes a touchdown bearing;
the gas purge port is provided in the stage mounting portion, and is configured such that a portion of the gas supplied from the gas purge port passes through the exhaust side space after passing through the touchdown bearing or the rolling bearing .
Gas transfer device. 2. The gas transfer device of claim 1 , wherein the touchdown bearing is glass coated. The gas transfer device according to claim 1, further comprising a connector provided at the bottom of the exhaust side of the gas transfer device for electrically connecting the inside and outside of the gas transfer device. 4. The gas transfer device according to claim 3 , wherein a groove for laying wiring connected to said connector is formed on an outer circumferential surface of the cylindrical portion of said inner cylinder. The gas transfer device according to claim 1 , wherein a spiral structure is formed in the gas outlet passage. The gas transfer device according to claim 1 , wherein the stage attachment portion is provided separably from the inner cylinder. The gas transfer device according to claim 6 , wherein the rotor blades and the stator blades can be removed from the gas transfer device by separating the stage mounting portion from the inner cylinder. The motor is an axial gap motor including a rotor and a stator,
The rotor is provided on the exhaust side of the rotor blade,
The gas transfer device according to claim 1 , wherein the stator is provided at a position opposite to the rotor on the gas flow path. 9. A method of using a gas transfer device according to any one of claims 1 to 8 in connection with a vacuum chamber, comprising the steps of:
supplying a gas to the exhaust side space through the gas purge port when at least one of the following conditions is met: (1) a predetermined type of gas is being supplied to the vacuum chamber ; and (2) a degree of vacuum inside the vacuum chamber is equal to or greater than a predetermined value.
The method includes:

Images